[v1,5/6] Sure Admin Security Feature

Commit Message

Jorge Lopez April 4, 2022, 8:36 p.m. UTC

HP Commercial PC’s have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.  To
prevent unauthorized changes to these settings, the system can be
configured to use a Sure Admin cryptographic signature-based
authorization string that the BIOS will use to verify authorization to
modify the setting. Behind the scenes, Sure Admin uses Secure Platform
Management (SPM) and WMI

'settings' is a file associated with Sure Admin. BIOS settings can be
read or written through the Sure Admin settings file in sysfs

	/sys/devices/platform/hp-wmi/sure_admin/settings

Expected data format to update BIOS setting

	[BIOS setting],[new value],[auth token]

Sample settings reported data

	{
		"Class": "HPBIOS_BIOSEnumeration",
		"Name": "USB Storage Boot",
		"Path": "\\Advanced\\Boot Options",
		"IsReadOnly": 0,
		...
		"Value": "Enable",
		"Size": 2,
		"PossibleValues": [
			"Disable",
			"Enable"
		]
	}

This feature requires "Update hp_wmi_group to simplify feature
addition" patch.

All changes were validated on a HP ZBook Workstation,
HP EliteBook x360, and HP EliteBook 850 G8 notebooks.

Signed-off-by: Jorge Lopez <[e-mail]>

---
Based on the latest platform-drivers-x86.git/for-next
---
 drivers/platform/x86/hp-wmi.c | 977 ++++++++++++++++++++++++++++++++++
 1 file changed, 977 insertions(+)

Comments

Mario Limonciello April 4, 2022, 9:59 p.m. UTC | #1

[Public]



> -----Original Message-----
> From: Jorge Lopez <[e-mail]>
> Sent: Monday, April 4, 2022 15:36
> To: [e-mail]
> Subject: [PATCH v1 5/6] Sure Admin Security Feature
> 
> HP Commercial PC’s have several BIOS settings that control its
> behaviour and capabilities, many of which are related to security.  To
> prevent unauthorized changes to these settings, the system can be
> configured to use a Sure Admin cryptographic signature-based
> authorization string that the BIOS will use to verify authorization to
> modify the setting. Behind the scenes, Sure Admin uses Secure Platform
> Management (SPM) and WMI
> 
> 'settings' is a file associated with Sure Admin. BIOS settings can be
> read or written through the Sure Admin settings file in sysfs
> 
> 	/sys/devices/platform/hp-wmi/sure_admin/settings
> 
> Expected data format to update BIOS setting
> 
> 	[BIOS setting],[new value],[auth token]
> 
> Sample settings reported data
> 
> 	{
> 		"Class": "HPBIOS_BIOSEnumeration",
> 		"Name": "USB Storage Boot",
> 		"Path": "\\Advanced\\Boot Options",
> 		"IsReadOnly": 0,
> 		...
> 		"Value": "Enable",
> 		"Size": 2,
> 		"PossibleValues": [
> 			"Disable",
> 			"Enable"
> 		]
> 	}
> 

This sounds like it has re-invented /sys/class/firmware-attributes.

Shouldn't you adopt that API?

> This feature requires "Update hp_wmi_group to simplify feature
> addition" patch.
> 
> All changes were validated on a HP ZBook Workstation,
> HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
> 
> Signed-off-by: Jorge Lopez <[e-mail]>
> 
> ---
> Based on the latest platform-drivers-x86.git/for-next
> ---
>  drivers/platform/x86/hp-wmi.c | 977
> ++++++++++++++++++++++++++++++++++
>  1 file changed, 977 insertions(+)
> 
> diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
> index 918e3eaf1b67..b72ca18b77a6 100644
> --- a/drivers/platform/x86/hp-wmi.c
> +++ b/drivers/platform/x86/hp-wmi.c
> @@ -27,6 +27,7 @@
>  #include <linux/rfkill.h>
>  #include <linux/string.h>
>  #include <linux/dmi.h>
> +#include <linux/nls.h>
> 
>  MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
>  MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
> @@ -37,8 +38,16 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-
> 3D44E2C707E4");
> 
>  #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-ACCDC67EF61C"
>  #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-3D44E2C707E4"
> +
>  #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
> 
> +#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-6A1B8106F83C"
> +#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-
> E293ADB9BF05"
> +#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-
> 4A3C09E75133"
> +#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-A0E0-
> 7045CB4DA745"
> +#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-
> 015176049E2D"
> +#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-951D-
> C7CB9B4B8D5E"
> +
>  /* DMI board names of devices that should use the omen specific path for
>   * thermal profiles.
>   * This was obtained by taking a look in the windows omen command center
> @@ -1025,6 +1034,973 @@ static const struct attribute_group
> sure_start_group = {
>  	.attrs = sure_start_attrs,
>  };
> 
> +
> +static int convert_hexstr_to_str(char **hex, int input_len, char **str, int
> *len)
> +{
> +	int ret = 0;
> +	int new_len = 0;
> +	char tmp[] = "0x00";
> +	char *input = *hex;
> +	char *new_str = NULL;
> +	int  ch;
> +	int i;
> +
> +	if (input_len <= 0 || hex == NULL || str == NULL || len == NULL)
> +		return -EINVAL;
> +
> +	*len = 0;
> +	*str = NULL;
> +
> +	new_str = kmalloc(input_len, GFP_KERNEL);
> +	if (!new_str)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < input_len; i += 5) {
> +		strncpy(tmp, input + i, strlen(tmp));
> +		ret = kstrtoint(tmp, 16, &ch);
> +		if (ret) {
> +			new_len = 0;
> +			break;
> +		}
> +
> +		if (ch == '\\')
> +			new_str[new_len++] = '\\';
> +
> +		new_str[new_len++] = ch;
> +		if (ch == '\0')
> +			break;
> +	}
> +
> +	if (new_len) {
> +		new_str[new_len] = '\0';
> +		*str = krealloc(new_str, (new_len + 1) * sizeof(char),
> GFP_KERNEL);
> +		if (*str)
> +			*len = new_len;
> +		else
> +			ret = -ENOMEM;
> +	}
> +
> +	if (ret)
> +		kfree(new_str);
> +	return ret;
> +}
> +
> +/*
> + * hp_wmi_get_setting_object() - Get an ACPI object by GUID and instance
> + *
> + * @guid:	GUID associated with the ACPI list of managed objects
> + * @instance:	Instance index to query on the ACPI list
> + * @obj:	The output ACPI object of type ACPI_TYPE_PACKAGE
> + *		or ACPI_TYPE_BUFFER (freed by the callee)
> + *
> + * Returns	zero on success.  Otherwise,an error inherited from
> + *		wmi_query_block(). It returns a obj by parameter if
> + *		the query returned object of type buffer or package,
> + *		otherwise, a null obj is returned.
> + *
> + * Note: obj should be freed by the callee once it is finished working with it
> + */
> +static int hp_wmi_get_setting_object(char *guid, int instance,
> +				union acpi_object **obj)
> +{
> +	struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER, NULL
> };
> +	union acpi_object *tmp = NULL;
> +	int ret;
> +
> +	ret = wmi_query_block(guid, instance, &output);
> +	if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
> +		tmp = output.pointer;
> +		if (tmp->type == ACPI_TYPE_BUFFER || tmp->type ==
> ACPI_TYPE_PACKAGE)
> +			*obj = output.pointer;
> +		else {
> +			kfree(tmp);
> +			*obj = NULL;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +
> +static int get_string_from_buffer(u16 **buffer, char **str)
> +{
> +	u16 *ptr = *buffer;
> +	u16 ptrlen;
> +
> +	u16 size;
> +	int i;
> +	char *output = NULL;
> +	int escape = 0;
> +
> +	ptrlen = *(ptr++);
> +	size = ptrlen / 2;
> +
> +	if (size == 0)
> +		goto cleanup_exit;
> +
> +	for (i = 0; i < size; i++)
> +		if (ptr[i] == '\\')
> +			escape++;
> +
> +	size += escape;
> +	*str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
> +	if (!*str)
> +		return -ENOMEM;
> +
> +	output = *str;
> +
> +	/*
> +	 * convert from UTF-16 unicode to ASCII
> +	 */
> +	utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output, size);
> +
> +	if (escape == 0) {
> +		ptr += (ptrlen / 2);
> +		goto cleanup_exit;
> +	}
> +	/*
> +	 * Convert escape characters only when found
> +	 */
> +	for (i = 0; i < size; i++) {
> +		if (*ptr == '\\')
> +			output[i++] = '\\';
> +		output[i] = *ptr;
> +		ptr++;
> +	}
> +
> +cleanup_exit:
> +	*buffer = ptr;
> +	return 0;
> +}
> +
> +static int get_integer_from_buffer(int **buffer, int *integer)
> +{
> +	int *ptr = PTR_ALIGN(*buffer, 4);
> +	*integer = *(ptr++);
> +	*buffer = ptr;
> +	return 0;
> +}
> +
> +
> +// Sure Admin functions
> +enum hp_wmi_data_type {
> +	HPWMI_STRING_TYPE,
> +	HPWMI_INTEGER_TYPE,
> +	HPWMI_ENUMERATION_TYPE,
> +	HPWMI_ORDEREDLIST_TYPE,
> +	HPWMI_PASSWORD_TYPE,
> +};
> +
> +#define HP_WMI_COMMON_ELEMENTS	\
> +	"Name",	\
> +	"Value",	\
> +	"Path",	\
> +	"IsReadOnly",	\
> +	"DisplayInUI",	\
> +	"RequiresPhysicalPresence",	\
> +	"Sequence",	\
> +	"PrerequisiteSize",	\
> +	"SecurityLevel"
> +
> +const char *hp_wmi_string_elements[] = {
> +	HP_WMI_COMMON_ELEMENTS,
> +	"MinLength",
> +	"MaxLength"
> +};
> +
> +const char *hp_wmi_integer_elements[] = {
> +	HP_WMI_COMMON_ELEMENTS,
> +	"LowerBound",
> +	"UpperBound",
> +	"IntValue"
> +};
> +
> +const char *hp_wmi_enumeration_elements[] = {
> +	HP_WMI_COMMON_ELEMENTS,
> +	"CurrentValue",
> +	"Size"
> +};
> +
> +const char *hp_wmi_orderedlist_elements[] = {
> +	HP_WMI_COMMON_ELEMENTS,
> +	"Size"
> +};
> +
> +const char *hp_wmi_password_elements[] = {
> +	HP_WMI_COMMON_ELEMENTS,
> +	"MinLength",
> +	"MaxLength",
> +	"Size",
> +	"SupportedEncoding",
> +	"IsSet"
> +};
> +
> +const char **hp_wmi_elements[] = {
> +	hp_wmi_string_elements,
> +	hp_wmi_integer_elements,
> +	hp_wmi_enumeration_elements,
> +	hp_wmi_orderedlist_elements,
> +	hp_wmi_password_elements
> +};
> +
> +const int hp_wmi_elements_count[] = {
> +	ARRAY_SIZE(hp_wmi_string_elements),
> +	ARRAY_SIZE(hp_wmi_integer_elements),
> +	ARRAY_SIZE(hp_wmi_enumeration_elements),
> +	ARRAY_SIZE(hp_wmi_orderedlist_elements),
> +	ARRAY_SIZE(hp_wmi_password_elements)
> +};
> +
> +const char *hp_wmi_classes[] = {
> +	"HPBIOS_BIOSString",
> +	"HPBIOS_BIOSInteger",
> +	"HPBIOS_BIOSEnumeration",
> +	"HPBIOS_BIOSOrderedList",
> +	"HPBIOS_BIOSPassword"
> +};
> +
> +static DEFINE_MUTEX(buf_mutex);
> +static int settings_buffer_size;
> +static int buf_alloc_size;
> +static char *hp_bios_settings_buffer;
> +
> +
> +static int append_package_elements_to_buffer(union acpi_object *obj,
> +					     char *buf, int alloc_size, enum
> hp_wmi_data_type type)
> +{
> +	int i;
> +	union acpi_object *pobj = NULL;
> +	char *value = NULL;
> +	int value_len;
> +	char *tmpstr = NULL;
> +	char *part_tmp = NULL;
> +	int tmp_len = 0;
> +	char *part = NULL;
> +	int status = 0;
> +	int size = 0;
> +	int buf_size;
> +
> +	if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> +		return -EINVAL;
> +
> +	if (obj->type != ACPI_TYPE_PACKAGE)
> +		return -EINVAL;
> +
> +	buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> +	buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> hp_wmi_classes[type]);
> +
> +	for (i = 0; i < 3; i++) {
> +		pobj = &(obj->package.elements[i]);
> +		if (pobj->type == ACPI_TYPE_STRING) {
> +			status = convert_hexstr_to_str(&pobj-
> >string.pointer,
> +						       pobj->string.length,
> &value, &value_len);
> +			if (ACPI_FAILURE(status))
> +				continue;
> +			/*
> +			 * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> since
> +			 * 'CurrentValue' is reported.
> +			 */
> +			if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> +				buf_size = snprintf(buf, alloc_size,
> +						    "%s\t\"%s\": \"%s\",\n",
> +						    buf,
> +
> hp_wmi_elements[type][i], value);
> +
> +		}
> +		kfree(value);
> +		value = NULL;
> +	}
> +
> +	for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> +		pobj = &(obj->package.elements[i]);
> +
> +		if (type == HPWMI_ENUMERATION_TYPE &&
> +		    i == 9 &&
> +		    pobj->type == ACPI_TYPE_STRING) {
> +			/*
> +			 * Report "CurrentValue" as "Value"
> +			 */
> +			status = convert_hexstr_to_str(&pobj-
> >string.pointer,
> +						       pobj->string.length,
> +						       &value, &value_len);
> +			if (ACPI_FAILURE(status))
> +				continue;
> +
> +			buf_size = snprintf(buf, alloc_size,
> +					    "%s\t\"Value\": \"%s\",\n",
> +					    buf, value);
> +			kfree(value);
> +			value = NULL;
> +
> +		} else if (type == HPWMI_PASSWORD_TYPE &&
> +			   i == 12 &&
> +			   pobj->type == ACPI_TYPE_STRING) {
> +			/*
> +			 * Report list of "SupportEncoding"
> +			 *
> +			 *	"SupportedEncoding": [
> +			 *		"utf-16"
> +			 *	],
> +			 *
> +			 */
> +
> +			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> +					    buf, hp_wmi_elements[type][i]);
> +			while (size--) {
> +				pobj = &(obj->package.elements[i]);
> +				status = convert_hexstr_to_str(&pobj-
> >string.pointer,
> +							       pobj-
> >string.length,
> +							       &value,
> &value_len);
> +				if (ACPI_FAILURE(status))
> +					continue;
> +
> +				if (size) {
> +					buf_size = snprintf(buf, alloc_size,
> +							    "%s\t\t\"%s\",\n",
> buf, value);
> +					i++;
> +				} else
> +					buf_size = snprintf(buf, alloc_size,
> +							    "%s\t\t\"%s\"\n",
> buf, value);
> +
> +				kfree(value);
> +				value = NULL;
> +
> +			}
> +			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> +			continue;
> +
> +		} else if (pobj->type == ACPI_TYPE_INTEGER) {
> +			/*
> +			 * Report "PrerequisiteSize" and "Size" values
> +			 *	...
> +			 *	"PrerequisiteSize": 1,
> +			 *	...
> +			 *	"Size": 2,
> +			 *	...
> +			 */
> +			if (i == 7)
> +				size = pobj->integer.value;
> +			else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> 9)
> +				size = pobj->integer.value;
> +			else if (type == HPWMI_ENUMERATION_TYPE && i
> == 10)
> +				size = pobj->integer.value;
> +			else if (type == HPWMI_PASSWORD_TYPE && i ==
> 11)
> +				size = pobj->integer.value;
> +
> +			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> %lld,\n", buf,
> +					    hp_wmi_elements[type][i], pobj-
> >integer.value);
> +		}
> +	}
> +
> +	if (type == HPWMI_ENUMERATION_TYPE) {
> +		buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\":
> [\n", buf);
> +		for (i = 0; i < size; i++) {
> +			pobj = &(obj->package.elements[i +
> hp_wmi_elements_count[type]]);
> +
> +			status = convert_hexstr_to_str(&pobj-
> >string.pointer,
> +						       pobj->string.length,
> +						       &value, &value_len);
> +			if (ACPI_FAILURE(status))
> +				break;
> +
> +			/*
> +			 * Report list of "PossibleValues" of size
> +			 * "Size"
> +			 *	...
> +			 *	"Size": 2,
> +			 *	"PossibleValues": [
> +			 *			"Disable",
> +			 *			"Enable"]
> +			 */
> +			if (i == (size - 1))
> +				buf_size = snprintf(buf, alloc_size,
> +						    "%s\t\t\"%s\"\n", buf,
> value);
> +			else
> +				buf_size = snprintf(buf, alloc_size,
> +						    "%s\t\t\"%s\",\n", buf,
> value);
> +			kfree(value);
> +			value = NULL;
> +		}
> +		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> +	}
> +
> +	if (type == HPWMI_ORDEREDLIST_TYPE) {
> +		buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n",
> buf);
> +		if (size <= 0)
> +			goto finish_ordered_list;
> +
> +		pobj = &(obj-
> >package.elements[hp_wmi_elements_count[type]]);
> +		status = convert_hexstr_to_str(&pobj->string.pointer,
> +					       pobj->string.length, &value,
> &value_len);
> +		if (ACPI_FAILURE(status))
> +			goto finish_ordered_list;
> +
> +		/*
> +		 * Ordered list data is stored in hex and comma separated
> format
> +		 * Convert the data and split it to show each element
> +		 */
> +		status = convert_hexstr_to_str(&value, value_len, &tmpstr,
> &tmp_len);
> +		if (ACPI_FAILURE(status))
> +			goto finish_ordered_list;
> +
> +		part_tmp = tmpstr;
> +		part = strsep(&part_tmp, ",");
> +		while (part) {
> +			buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"",
> buf, part);
> +			part = strsep(&part_tmp, ",");
> +			if (part)
> +				buf_size = snprintf(buf, alloc_size, "%s,\n",
> buf);
> +			else
> +				buf_size = snprintf(buf, alloc_size, "%s\n",
> buf);
> +		}
> +	}
> +
> +finish_ordered_list:
> +	if (type == HPWMI_ORDEREDLIST_TYPE)
> +		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> +
> +	/*
> +	 * remove trailing comma
> +	 */
> +	if (buf_size > 3)
> +		buf[buf_size - 2] = ' ';
> +
> +	kfree(tmpstr);
> +	kfree(value);
> +	return snprintf(buf, alloc_size, "%s},\n", buf);
> +}
> +
> +static int append_buffer_elements_to_buffer(union acpi_object *obj,
> +					    char *buf, int alloc_size, enum
> hp_wmi_data_type type)
> +{
> +	int buf_size;
> +	int status;
> +	char *str = NULL;
> +	int i;
> +	int j;
> +	int integer;
> +	int size = 0;
> +
> +	if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> +		return -EINVAL;
> +
> +	if (obj->type != ACPI_TYPE_BUFFER)
> +		return -EINVAL;
> +
> +	buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> +	buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> hp_wmi_classes[type]);
> +
> +	for (i = 0; i < 3; i++) {
> +		status = get_string_from_buffer((u16 **)&obj-
> >buffer.pointer, &str);
> +		if (ACPI_SUCCESS(status)) {
> +			/*
> +			 * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> since
> +			 * 'CurrentValue' is reported.
> +			 */
> +			if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> +				buf_size = snprintf(buf, alloc_size,
> +						    "%s\t\"%s\": \"%s\",\n",
> +						    buf,
> +
> hp_wmi_elements[type][i], str);
> +		}
> +		kfree(str);
> +		str = NULL;
> +
> +	}
> +
> +	for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> +		if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
> +			status = get_string_from_buffer((u16 **)&obj-
> >buffer.pointer, &str);
> +			if (ACPI_SUCCESS(status)) {
> +				/*
> +				 * Report "CurrentValue" as "Value"
> +				 */
> +				buf_size = snprintf(buf, alloc_size,
> +						    "%s\t\"Value\": \"%s\",\n",
> buf, str);
> +			}
> +			kfree(str);
> +			str = NULL;
> +			continue;
> +
> +		} else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
> +			/*
> +			 * Report list of "SupportEncoding"
> +			 *
> +			 *	"SupportedEncoding": [
> +			 *		"utf-16"
> +			 *	],
> +			 *
> +			 */
> +
> +			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> +					    buf, hp_wmi_elements[type][i]);
> +			for (j = 0; j < size; j++) {
> +				status = get_string_from_buffer((u16
> **)&obj->buffer.pointer, &str);
> +				if (ACPI_SUCCESS(status)) {
> +					if (j == size - 1)
> +						buf_size = snprintf(buf,
> alloc_size,
> +
> "%s\t\t\"%s\"\n", buf, str);
> +					else
> +						buf_size = snprintf(buf,
> alloc_size,
> +
> "%s\t\t\"%s\",\n", buf, str);
> +				}
> +				kfree(str);
> +				str = NULL;
> +			}
> +			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> +			continue;
> +		}
> +
> +		size = 0;
> +		status = get_integer_from_buffer((int **)&obj-
> >buffer.pointer, &integer);
> +		if (ACPI_SUCCESS(status)) {
> +			/*
> +			 * Report "PrerequisiteSize" and "Size" values
> +			 *	...
> +			 *	"PrerequisiteSize": 1,
> +			 *	...
> +			 *	"Size": 2,
> +			 *	...
> +			 */
> +			if (i == 7)
> +				size = integer;
> +			else if (type == HPWMI_ENUMERATION_TYPE && i
> == 10)
> +				size = integer;
> +			else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> 9)
> +				size = integer;
> +			else if (type == HPWMI_PASSWORD_TYPE && i ==
> 11)
> +				size = integer;
> +
> +			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> %d,\n", buf,
> +					    hp_wmi_elements[type][i],
> integer);
> +		}
> +
> +		if (size > 20)
> +			pr_warn("%s exceeded the maximum number of
> elements supported or data may be malformed\n",
> +				hp_wmi_elements[type][i]);
> +
> +		if (ACPI_SUCCESS(status) && i == 7) {
> +			buf_size = snprintf(buf, alloc_size,
> "%s\t\"Prerequisites\": [\n", buf);
> +			for (j = 0; j < size; j++) {
> +				status = get_string_from_buffer((u16
> **)&obj->buffer.pointer, &str);
> +				if (ACPI_SUCCESS(status)) {
> +					buf_size = snprintf(buf, alloc_size,
> "%s\t\t\"%s\"", buf, str);
> +
> +					if (j == size - 1)
> +						buf_size = snprintf(buf,
> alloc_size, "%s\n", buf);
> +					else
> +						buf_size = snprintf(buf,
> alloc_size, "%s,\n", buf);
> +
> +				}
> +				kfree(str);
> +				str = NULL;
> +			}
> +			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> +		}
> +	}
> +
> +	if (type == HPWMI_ENUMERATION_TYPE || type ==
> HPWMI_ORDEREDLIST_TYPE) {
> +		if (type == HPWMI_ENUMERATION_TYPE)
> +			buf_size = snprintf(buf, alloc_size,
> "%s\t\"PossibleValues\": [\n", buf);
> +		else
> +			buf_size = snprintf(buf, alloc_size,
> "%s\t\"Elements\": [\n", buf);
> +
> +		for (i = 0; i < size; i++) {
> +			status = get_string_from_buffer((u16 **)&obj-
> >buffer.pointer, &str);
> +			if (ACPI_SUCCESS(status)) {
> +				buf_size = snprintf(buf, alloc_size,
> "%s\t\t\"%s\"", buf, str);
> +
> +				if (i == size - 1)
> +					buf_size = snprintf(buf, alloc_size,
> "%s\n", buf);
> +				else
> +					buf_size = snprintf(buf, alloc_size,
> "%s,\n", buf);
> +
> +			}
> +			kfree(str);
> +			str = NULL;
> +		}
> +		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> +	}
> +
> +	/*
> +	 * remove trailing comma
> +	 */
> +	if (buf_size > 3)
> +		buf[buf_size - 2] = ' ';
> +
> +	return snprintf(buf, alloc_size, "%s},\n", buf);
> +}
> +
> +static int hp_bios_settings_free_buffer(void)
> +{
> +	mutex_lock(&buf_mutex);
> +	kfree(hp_bios_settings_buffer);
> +	settings_buffer_size = 0;
> +	buf_alloc_size = 0;
> +	mutex_unlock(&buf_mutex);
> +
> +	return 0;
> +}
> +
> +static int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
> +					   int *alloc_size,
> +					   struct mutex *buf_mutex)
> +{
> +	int new_buffer_size;
> +	char *new_buf = NULL;
> +	int ret = 0;
> +
> +	if (*buf_size + PAGE_SIZE >= *alloc_size) {
> +		new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
> +
> +		mutex_lock(buf_mutex);
> +		new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
> +		mutex_unlock(buf_mutex);
> +		if (new_buf) {
> +			mutex_lock(buf_mutex);
> +			*buf = new_buf;
> +			*alloc_size = ksize(new_buf);
> +			mutex_unlock(buf_mutex);
> +		} else {
> +			hp_bios_settings_free_buffer();
> +			ret = -ENOMEM;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static int append_settings_to_buffer(char *guid, int type, char **buf,
> +				     int *buf_size, int *alloc_size,
> +				     struct mutex *buf_mutex)
> +{
> +	union acpi_object *obj = NULL;
> +	int ret = 0;
> +	int status = 0;
> +	int instance = 0;
> +
> +	/*
> +	 * Query all the instances until to receive a AE_BAD_PARAMETER
> +	 */
> +	do {
> +		ret = hp_wmi_get_setting_object(guid, instance++, &obj);
> +		if (ACPI_SUCCESS(ret) && obj != NULL) {
> +			status = 0;
> +			if (obj->type == ACPI_TYPE_PACKAGE) {
> +				mutex_lock(buf_mutex);
> +				status =
> append_package_elements_to_buffer(obj,
> +							*buf, *alloc_size,
> type);
> +				if (status > 0)
> +					*buf_size = status;
> +				mutex_unlock(buf_mutex);
> +
> +			} else if (obj->type == ACPI_TYPE_BUFFER) {
> +				mutex_lock(buf_mutex);
> +				status =
> append_buffer_elements_to_buffer(obj,
> +							*buf, *alloc_size,
> type);
> +				if (status > 0)
> +					*buf_size = status;
> +				mutex_unlock(buf_mutex);
> +
> +			} else
> +				pr_warn("The retrieved object type(%d) is
> not supported yet\n",
> +					obj->type);
> +
> +			ret = hp_bios_settings_realloc_buffer(buf, buf_size,
> alloc_size, buf_mutex);
> +		}
> +
> +		kfree(obj);
> +		obj = NULL;
> +
> +	} while (ACPI_SUCCESS(ret));
> +
> +	/*
> +	 * AE_BAD_PARAMETER means the loop ended by exhaustion
> +	 */
> +	if (ret == AE_BAD_PARAMETER)
> +		ret = 0;
> +
> +	return ret;
> +}
> +
> +static int hp_bios_settings_fill_buffer(void)
> +{
> +	int status = 0;
> +	int initial_buffer_size = 20 * PAGE_SIZE;
> +
> +	mutex_lock(&buf_mutex);
> +	hp_bios_settings_buffer = kmalloc(initial_buffer_size, GFP_KERNEL);
> +	mutex_unlock(&buf_mutex);
> +	if (!hp_bios_settings_buffer)
> +		return -ENOMEM;
> +
> +	mutex_lock(&buf_mutex);
> +	buf_alloc_size = ksize(hp_bios_settings_buffer);
> +	settings_buffer_size = snprintf(hp_bios_settings_buffer,
> +					buf_alloc_size, "[\n");
> +	mutex_unlock(&buf_mutex);
> +
> +	status = append_settings_to_buffer(HPWMI_STRING_GUID,
> +		HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
> +	if (ACPI_FAILURE(status))
> +		pr_err("error 0x%x occurred retrieving string instances\n",
> status);
> +
> +	status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
> +		HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
> +	if (ACPI_FAILURE(status))
> +		pr_err("error 0x%x occurred retrieving integer instances\n",
> status);
> +
> +	status = append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
> +		HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
> +	if (ACPI_FAILURE(status))
> +		pr_err("error 0x%x occurred retrieving enumeration
> instances\n", status);
> +
> +	status = append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
> +		HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
> +	if (ACPI_FAILURE(status))
> +		pr_err("error 0x%x occurred retrieving ordered list
> instances\n", status);
> +
> +	status = append_settings_to_buffer(HPWMI_PASSWORD_GUID,
> +		HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
> +	if (ACPI_FAILURE(status))
> +		pr_err("error 0x%x occurred retrieving password list
> instances\n", status);
> +
> +	mutex_lock(&buf_mutex);
> +	/*
> +	 * remove trailing comma
> +	 */
> +	if (settings_buffer_size >= 3) {
> +		if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
> +			hp_bios_settings_buffer[settings_buffer_size - 2] = '
> ';
> +	}
> +	settings_buffer_size = snprintf(hp_bios_settings_buffer,
> +					buf_alloc_size, "%s]\n",
> +					hp_bios_settings_buffer);
> +	mutex_unlock(&buf_mutex);
> +
> +	return settings_buffer_size;
> +}
> +
> +/*
> + * sure_admin_settings_read - Return a formatted file with settings
> + *                              and possible options read from BIOS
> + *
> + * @filp:  Pointer to file of settings read from BIOS
> + * @kobj:  Pointer to a kernel object of things that show up as directory in
> the sysfs filesystem.
> + * @attr:  Pointer to list of read attributes
> + * @buf:   Pointer to buffer
> + * @off:   File current offset
> + * @count: Buffer size
> + *
> + * Returns the count of unicode chars read if successful, otherwise
> + *		-ENOMEM unable to allocate memory
> + *		-EINVAL buffer not allocated or too small
> + *
> + */
> +static ssize_t sure_admin_settings_read(struct file *filp, struct kobject
> *kobj,
> +					struct bin_attribute *attr, char *buf,
> loff_t off, size_t count)
> +{
> +	ssize_t ret;
> +
> +	/* clear the buffer when offset is pointing to the last position */
> +	if (off >= settings_buffer_size && settings_buffer_size > 0) {
> +		hp_bios_settings_free_buffer();
> +		return 0;
> +	}
> +
> +	/* clear the buffer whenever the read starts from the first position
> */
> +	if (off == 0 && settings_buffer_size > 0)
> +		hp_bios_settings_free_buffer();
> +
> +	if (settings_buffer_size == 0)
> +		hp_bios_settings_fill_buffer();
> +
> +	mutex_lock(&buf_mutex);
> +	ret = memory_read_from_buffer(buf, count, &off,
> hp_bios_settings_buffer,
> +				      settings_buffer_size);
> +	mutex_unlock(&buf_mutex);
> +
> +	return ret;
> +}
> +
> +
> +/*
> + * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
> + *
> + * @p:   Unicode buffer address
> + * @str: string to convert to unicode
> + *
> + * Returns a void pointer to the buffer containing unicode string
> + */
> +static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
> +{
> +	int len = strlen(str);
> +
> +	/*
> +	 * Add null character when reading an empty string
> +	 */
> +	if (len == 0) {
> +		*p++ = 2;
> +		*p++ = (u8)0x00;
> +		return p;
> +	}
> +	*p++ = len * 2;
> +	utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
> +	p += len;
> +
> +	return p;
> +}
> +
> +/*
> + * hp_wmi_set_bios_setting - Set setting's value in BIOS
> + *
> + * @input_buffer: Input buffer address
> + * @input_size:   Input buffer size
> + *
> + * Returns: Count of unicode characters written to BIOS if successful,
> otherwise
> + *		-ENOMEM unable to allocate memory
> + *		-EINVAL buffer not allocated or too small
> + */
> +static int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
> +{
> +	union acpi_object *obj;
> +	struct acpi_buffer input = {input_size, input_buffer};
> +	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
> +	int ret = 0;
> +
> +	ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID, 0, 1,
> &input, &output);
> +
> +	obj = output.pointer;
> +	if (!obj)
> +		return -EINVAL;
> +
> +	if (obj->type != ACPI_TYPE_INTEGER)
> +		ret = -EINVAL;
> +
> +	ret = obj->integer.value;
> +	kfree(obj);
> +	return ret;
> +}
> +
> +/* Sure Admin Functions */
> +
> +#define UTF_PREFIX			((unsigned char *)"<utf-16/>")
> +#define BEAM_PREFIX			((unsigned char
> *)"<BEAM/>")
> +
> +/*
> + * sure_admin_settings_write - Write the contents of a formatted file
> + *                               with settings and performs the logic
> + *                               to change any settings in BIOS.
> + *
> + * @filp:  Pointer to file of settings to be written to BIOS
> + * @kobj:  Pointer to a kernel object of things that show up as directory in
> the sysfs filesystem.
> + * @attr:  Pointer to list of attributes for the write operation
> + * @buf:   Pointer to buffer
> + * @off:   File current offset
> + * @count: Buffer size
> + *
> + *
> + * Returns the count of unicode characters written to BIOS if successful,
> otherwise
> + *		-ENOMEM unable to allocate memory
> + *		-EINVAL buffer not allocated or too small
> + *
> + */
> +static ssize_t sure_admin_settings_write(struct file *filp, struct kobject
> *kobj,
> +			struct bin_attribute *attr, char *buf, loff_t off, size_t
> count)
> +{
> +	int status = 0;
> +	char *part = NULL;
> +	int part_len = 0;
> +	unsigned short *buffer = NULL;
> +	unsigned short *tmpstr = NULL;
> +	int buffer_size = (count + strlen(UTF_PREFIX)) * sizeof(unsigned
> short);
> +
> +	buffer = kmalloc(buffer_size, GFP_KERNEL);
> +	if (!buffer)
> +		return -ENOMEM;
> +
> +	tmpstr = buffer;
> +	part = strsep(&buf, ",");
> +	if (!part) {
> +		status = -EINVAL;
> +		goto out_free;
> +	}
> +	tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> +	part = strsep(&buf, ",");
> +	if (!part) {
> +		status = -EINVAL;
> +		goto out_free;
> +	}
> +
> +	/* Add extra buffer space when encountering an empty string */
> +	if (!strlen(part))
> +		buffer_size += sizeof(unsigned short);
> +	tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> +	part = strsep(&buf, ",");
> +	if (!part) {
> +		status = -EINVAL;
> +		goto out_free;
> +	}
> +	part_len = strlen(part) - 1;
> +	part[part_len] = '\0';
> +
> +	if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
> +	       /*
> +		* BEAM_PREFIX is append to buffer when a signature
> +		* is provided and Sure Admin is enabled in BIOS
> +		*/
> +		// BEAM_PREFIX found, convert part to unicode
> +		tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> +		// decrease buffer size allocated initially for UTF_PREFIX
> +		buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
> +	} else {
> +		/*
> +		 * UTF-16 prefix is append to the * buffer when a BIOS
> +		 * admin password is configured in BIOS
> +		 */
> +
> +		// append UTF_PREFIX to part and then convert it to unicode
> +		part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
> +		if (!part)
> +			goto out_free;
> +
> +		tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> +		kfree(part);
> +	}
> +
> +	part = strsep(&buf, ",");
> +	if (part) {
> +		status = -EINVAL;
> +		goto out_free;
> +	}
> +	status = hp_wmi_set_bios_setting(buffer, buffer_size);
> +	if (ACPI_FAILURE(status))
> +		status = -EINVAL;
> +
> +out_free:
> +	kfree(buffer);
> +	if (ACPI_SUCCESS(status))
> +		return count;
> +	return status;
> +}
> +
> +HPWMI_BINATTR_RW(sure_admin, settings, 0);
> +
> +static struct bin_attribute *sure_admin_binattrs[] = {
> +	&sure_admin_settings,
> +	NULL,
> +};
> +
> +static const struct attribute_group sure_admin_group = {
> +	.name = "sure_admin",
> +	.bin_attrs = sure_admin_binattrs,
> +};
> +
>  static DEVICE_ATTR_RO(display);
>  static DEVICE_ATTR_RO(hddtemp);
>  static DEVICE_ATTR_RW(als);
> @@ -1050,6 +2026,7 @@ static const struct attribute_group
> *hp_wmi_groups[] = {
>  	&hp_wmi_group,
>  	&spm_group,
>  	&sure_start_group,
> +	&sure_admin_group,
>  	NULL,
>  };
> 
> --
> 2.25.1

Hans de Goede April 5, 2022, 11:54 a.m. UTC | #2

Hi,

On 4/4/22 23:59, Limonciello, Mario wrote:
> [Public]
> 
> 
> 
>> -----Original Message-----
>> From: Jorge Lopez <[e-mail]>
>> Sent: Monday, April 4, 2022 15:36
>> To: [e-mail]
>> Subject: [PATCH v1 5/6] Sure Admin Security Feature
>>
>> HP Commercial PC’s have several BIOS settings that control its
>> behaviour and capabilities, many of which are related to security.  To
>> prevent unauthorized changes to these settings, the system can be
>> configured to use a Sure Admin cryptographic signature-based
>> authorization string that the BIOS will use to verify authorization to
>> modify the setting. Behind the scenes, Sure Admin uses Secure Platform
>> Management (SPM) and WMI
>>
>> 'settings' is a file associated with Sure Admin. BIOS settings can be
>> read or written through the Sure Admin settings file in sysfs
>>
>> 	/sys/devices/platform/hp-wmi/sure_admin/settings
>>
>> Expected data format to update BIOS setting
>>
>> 	[BIOS setting],[new value],[auth token]
>>
>> Sample settings reported data
>>
>> 	{
>> 		"Class": "HPBIOS_BIOSEnumeration",
>> 		"Name": "USB Storage Boot",
>> 		"Path": "\\Advanced\\Boot Options",
>> 		"IsReadOnly": 0,
>> 		...
>> 		"Value": "Enable",
>> 		"Size": 2,
>> 		"PossibleValues": [
>> 			"Disable",
>> 			"Enable"
>> 		]
>> 	}
>>
> 
> This sounds like it has re-invented /sys/class/firmware-attributes.
> 
> Shouldn't you adopt that API?

I fully agree. Jorge as I already indicated in our off-list
conversation when you initially started working on this
feature, we already have a standardized API for querying/changing
BIOS settings from within Linux:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-class-firmware-attributes

and any new code (such as this patch) which implements BIOS
setting changing MUST follow this standardized API (extending
it where necessary).

I'm sorry but this patch is not acceptable in its current form,
it needs to be *completely rewritten* to implement:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-class-firmware-attributes

See:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/platform/x86/dell/dell-wmi-sysman
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/platform/x86/think-lmi.c

for example code / for 2 drivers from other vendors already
implementing this.

The same applies to the:

"[PATCH v1 3/6] Secure Platform Management Security Feature"

this needs to be implemented as
a /sys/class/firmware-attributes/*/authentication/
authentication method, see for example these Lenovo specific
addition to the /sys/class/firmware-attributes/*/authentication/
userspace API for similar functionality on Lenovo Think* devices:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=06384573a3e8335ac6797577e545c33dbf91b490

I'll merge patches 1-2 sometime this week since those are
fine and it will be good to have those "out of the way",
but the rest of the series will need to be rewritten
taken the above comments into account.

Regards,

Hans










> 
>> This feature requires "Update hp_wmi_group to simplify feature
>> addition" patch.
>>
>> All changes were validated on a HP ZBook Workstation,
>> HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
>>
>> Signed-off-by: Jorge Lopez <[e-mail]>
>>
>> ---
>> Based on the latest platform-drivers-x86.git/for-next
>> ---
>>  drivers/platform/x86/hp-wmi.c | 977
>> ++++++++++++++++++++++++++++++++++
>>  1 file changed, 977 insertions(+)
>>
>> diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
>> index 918e3eaf1b67..b72ca18b77a6 100644
>> --- a/drivers/platform/x86/hp-wmi.c
>> +++ b/drivers/platform/x86/hp-wmi.c
>> @@ -27,6 +27,7 @@
>>  #include <linux/rfkill.h>
>>  #include <linux/string.h>
>>  #include <linux/dmi.h>
>> +#include <linux/nls.h>
>>
>>  MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
>>  MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
>> @@ -37,8 +38,16 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-
>> 3D44E2C707E4");
>>
>>  #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-ACCDC67EF61C"
>>  #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-3D44E2C707E4"
>> +
>>  #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
>>
>> +#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-6A1B8106F83C"
>> +#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-
>> E293ADB9BF05"
>> +#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-
>> 4A3C09E75133"
>> +#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-A0E0-
>> 7045CB4DA745"
>> +#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-
>> 015176049E2D"
>> +#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-951D-
>> C7CB9B4B8D5E"
>> +
>>  /* DMI board names of devices that should use the omen specific path for
>>   * thermal profiles.
>>   * This was obtained by taking a look in the windows omen command center
>> @@ -1025,6 +1034,973 @@ static const struct attribute_group
>> sure_start_group = {
>>  	.attrs = sure_start_attrs,
>>  };
>>
>> +
>> +static int convert_hexstr_to_str(char **hex, int input_len, char **str, int
>> *len)
>> +{
>> +	int ret = 0;
>> +	int new_len = 0;
>> +	char tmp[] = "0x00";
>> +	char *input = *hex;
>> +	char *new_str = NULL;
>> +	int  ch;
>> +	int i;
>> +
>> +	if (input_len <= 0 || hex == NULL || str == NULL || len == NULL)
>> +		return -EINVAL;
>> +
>> +	*len = 0;
>> +	*str = NULL;
>> +
>> +	new_str = kmalloc(input_len, GFP_KERNEL);
>> +	if (!new_str)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < input_len; i += 5) {
>> +		strncpy(tmp, input + i, strlen(tmp));
>> +		ret = kstrtoint(tmp, 16, &ch);
>> +		if (ret) {
>> +			new_len = 0;
>> +			break;
>> +		}
>> +
>> +		if (ch == '\\')
>> +			new_str[new_len++] = '\\';
>> +
>> +		new_str[new_len++] = ch;
>> +		if (ch == '\0')
>> +			break;
>> +	}
>> +
>> +	if (new_len) {
>> +		new_str[new_len] = '\0';
>> +		*str = krealloc(new_str, (new_len + 1) * sizeof(char),
>> GFP_KERNEL);
>> +		if (*str)
>> +			*len = new_len;
>> +		else
>> +			ret = -ENOMEM;
>> +	}
>> +
>> +	if (ret)
>> +		kfree(new_str);
>> +	return ret;
>> +}
>> +
>> +/*
>> + * hp_wmi_get_setting_object() - Get an ACPI object by GUID and instance
>> + *
>> + * @guid:	GUID associated with the ACPI list of managed objects
>> + * @instance:	Instance index to query on the ACPI list
>> + * @obj:	The output ACPI object of type ACPI_TYPE_PACKAGE
>> + *		or ACPI_TYPE_BUFFER (freed by the callee)
>> + *
>> + * Returns	zero on success.  Otherwise,an error inherited from
>> + *		wmi_query_block(). It returns a obj by parameter if
>> + *		the query returned object of type buffer or package,
>> + *		otherwise, a null obj is returned.
>> + *
>> + * Note: obj should be freed by the callee once it is finished working with it
>> + */
>> +static int hp_wmi_get_setting_object(char *guid, int instance,
>> +				union acpi_object **obj)
>> +{
>> +	struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER, NULL
>> };
>> +	union acpi_object *tmp = NULL;
>> +	int ret;
>> +
>> +	ret = wmi_query_block(guid, instance, &output);
>> +	if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
>> +		tmp = output.pointer;
>> +		if (tmp->type == ACPI_TYPE_BUFFER || tmp->type ==
>> ACPI_TYPE_PACKAGE)
>> +			*obj = output.pointer;
>> +		else {
>> +			kfree(tmp);
>> +			*obj = NULL;
>> +		}
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +
>> +static int get_string_from_buffer(u16 **buffer, char **str)
>> +{
>> +	u16 *ptr = *buffer;
>> +	u16 ptrlen;
>> +
>> +	u16 size;
>> +	int i;
>> +	char *output = NULL;
>> +	int escape = 0;
>> +
>> +	ptrlen = *(ptr++);
>> +	size = ptrlen / 2;
>> +
>> +	if (size == 0)
>> +		goto cleanup_exit;
>> +
>> +	for (i = 0; i < size; i++)
>> +		if (ptr[i] == '\\')
>> +			escape++;
>> +
>> +	size += escape;
>> +	*str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
>> +	if (!*str)
>> +		return -ENOMEM;
>> +
>> +	output = *str;
>> +
>> +	/*
>> +	 * convert from UTF-16 unicode to ASCII
>> +	 */
>> +	utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output, size);
>> +
>> +	if (escape == 0) {
>> +		ptr += (ptrlen / 2);
>> +		goto cleanup_exit;
>> +	}
>> +	/*
>> +	 * Convert escape characters only when found
>> +	 */
>> +	for (i = 0; i < size; i++) {
>> +		if (*ptr == '\\')
>> +			output[i++] = '\\';
>> +		output[i] = *ptr;
>> +		ptr++;
>> +	}
>> +
>> +cleanup_exit:
>> +	*buffer = ptr;
>> +	return 0;
>> +}
>> +
>> +static int get_integer_from_buffer(int **buffer, int *integer)
>> +{
>> +	int *ptr = PTR_ALIGN(*buffer, 4);
>> +	*integer = *(ptr++);
>> +	*buffer = ptr;
>> +	return 0;
>> +}
>> +
>> +
>> +// Sure Admin functions
>> +enum hp_wmi_data_type {
>> +	HPWMI_STRING_TYPE,
>> +	HPWMI_INTEGER_TYPE,
>> +	HPWMI_ENUMERATION_TYPE,
>> +	HPWMI_ORDEREDLIST_TYPE,
>> +	HPWMI_PASSWORD_TYPE,
>> +};
>> +
>> +#define HP_WMI_COMMON_ELEMENTS	\
>> +	"Name",	\
>> +	"Value",	\
>> +	"Path",	\
>> +	"IsReadOnly",	\
>> +	"DisplayInUI",	\
>> +	"RequiresPhysicalPresence",	\
>> +	"Sequence",	\
>> +	"PrerequisiteSize",	\
>> +	"SecurityLevel"
>> +
>> +const char *hp_wmi_string_elements[] = {
>> +	HP_WMI_COMMON_ELEMENTS,
>> +	"MinLength",
>> +	"MaxLength"
>> +};
>> +
>> +const char *hp_wmi_integer_elements[] = {
>> +	HP_WMI_COMMON_ELEMENTS,
>> +	"LowerBound",
>> +	"UpperBound",
>> +	"IntValue"
>> +};
>> +
>> +const char *hp_wmi_enumeration_elements[] = {
>> +	HP_WMI_COMMON_ELEMENTS,
>> +	"CurrentValue",
>> +	"Size"
>> +};
>> +
>> +const char *hp_wmi_orderedlist_elements[] = {
>> +	HP_WMI_COMMON_ELEMENTS,
>> +	"Size"
>> +};
>> +
>> +const char *hp_wmi_password_elements[] = {
>> +	HP_WMI_COMMON_ELEMENTS,
>> +	"MinLength",
>> +	"MaxLength",
>> +	"Size",
>> +	"SupportedEncoding",
>> +	"IsSet"
>> +};
>> +
>> +const char **hp_wmi_elements[] = {
>> +	hp_wmi_string_elements,
>> +	hp_wmi_integer_elements,
>> +	hp_wmi_enumeration_elements,
>> +	hp_wmi_orderedlist_elements,
>> +	hp_wmi_password_elements
>> +};
>> +
>> +const int hp_wmi_elements_count[] = {
>> +	ARRAY_SIZE(hp_wmi_string_elements),
>> +	ARRAY_SIZE(hp_wmi_integer_elements),
>> +	ARRAY_SIZE(hp_wmi_enumeration_elements),
>> +	ARRAY_SIZE(hp_wmi_orderedlist_elements),
>> +	ARRAY_SIZE(hp_wmi_password_elements)
>> +};
>> +
>> +const char *hp_wmi_classes[] = {
>> +	"HPBIOS_BIOSString",
>> +	"HPBIOS_BIOSInteger",
>> +	"HPBIOS_BIOSEnumeration",
>> +	"HPBIOS_BIOSOrderedList",
>> +	"HPBIOS_BIOSPassword"
>> +};
>> +
>> +static DEFINE_MUTEX(buf_mutex);
>> +static int settings_buffer_size;
>> +static int buf_alloc_size;
>> +static char *hp_bios_settings_buffer;
>> +
>> +
>> +static int append_package_elements_to_buffer(union acpi_object *obj,
>> +					     char *buf, int alloc_size, enum
>> hp_wmi_data_type type)
>> +{
>> +	int i;
>> +	union acpi_object *pobj = NULL;
>> +	char *value = NULL;
>> +	int value_len;
>> +	char *tmpstr = NULL;
>> +	char *part_tmp = NULL;
>> +	int tmp_len = 0;
>> +	char *part = NULL;
>> +	int status = 0;
>> +	int size = 0;
>> +	int buf_size;
>> +
>> +	if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
>> +		return -EINVAL;
>> +
>> +	if (obj->type != ACPI_TYPE_PACKAGE)
>> +		return -EINVAL;
>> +
>> +	buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
>> +	buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
>> hp_wmi_classes[type]);
>> +
>> +	for (i = 0; i < 3; i++) {
>> +		pobj = &(obj->package.elements[i]);
>> +		if (pobj->type == ACPI_TYPE_STRING) {
>> +			status = convert_hexstr_to_str(&pobj-
>>> string.pointer,
>> +						       pobj->string.length,
>> &value, &value_len);
>> +			if (ACPI_FAILURE(status))
>> +				continue;
>> +			/*
>> +			 * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
>> since
>> +			 * 'CurrentValue' is reported.
>> +			 */
>> +			if (type != HPWMI_ENUMERATION_TYPE || i != 1)
>> +				buf_size = snprintf(buf, alloc_size,
>> +						    "%s\t\"%s\": \"%s\",\n",
>> +						    buf,
>> +
>> hp_wmi_elements[type][i], value);
>> +
>> +		}
>> +		kfree(value);
>> +		value = NULL;
>> +	}
>> +
>> +	for (i = 3; i < hp_wmi_elements_count[type]; i++) {
>> +		pobj = &(obj->package.elements[i]);
>> +
>> +		if (type == HPWMI_ENUMERATION_TYPE &&
>> +		    i == 9 &&
>> +		    pobj->type == ACPI_TYPE_STRING) {
>> +			/*
>> +			 * Report "CurrentValue" as "Value"
>> +			 */
>> +			status = convert_hexstr_to_str(&pobj-
>>> string.pointer,
>> +						       pobj->string.length,
>> +						       &value, &value_len);
>> +			if (ACPI_FAILURE(status))
>> +				continue;
>> +
>> +			buf_size = snprintf(buf, alloc_size,
>> +					    "%s\t\"Value\": \"%s\",\n",
>> +					    buf, value);
>> +			kfree(value);
>> +			value = NULL;
>> +
>> +		} else if (type == HPWMI_PASSWORD_TYPE &&
>> +			   i == 12 &&
>> +			   pobj->type == ACPI_TYPE_STRING) {
>> +			/*
>> +			 * Report list of "SupportEncoding"
>> +			 *
>> +			 *	"SupportedEncoding": [
>> +			 *		"utf-16"
>> +			 *	],
>> +			 *
>> +			 */
>> +
>> +			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
>> +					    buf, hp_wmi_elements[type][i]);
>> +			while (size--) {
>> +				pobj = &(obj->package.elements[i]);
>> +				status = convert_hexstr_to_str(&pobj-
>>> string.pointer,
>> +							       pobj-
>>> string.length,
>> +							       &value,
>> &value_len);
>> +				if (ACPI_FAILURE(status))
>> +					continue;
>> +
>> +				if (size) {
>> +					buf_size = snprintf(buf, alloc_size,
>> +							    "%s\t\t\"%s\",\n",
>> buf, value);
>> +					i++;
>> +				} else
>> +					buf_size = snprintf(buf, alloc_size,
>> +							    "%s\t\t\"%s\"\n",
>> buf, value);
>> +
>> +				kfree(value);
>> +				value = NULL;
>> +
>> +			}
>> +			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>> +			continue;
>> +
>> +		} else if (pobj->type == ACPI_TYPE_INTEGER) {
>> +			/*
>> +			 * Report "PrerequisiteSize" and "Size" values
>> +			 *	...
>> +			 *	"PrerequisiteSize": 1,
>> +			 *	...
>> +			 *	"Size": 2,
>> +			 *	...
>> +			 */
>> +			if (i == 7)
>> +				size = pobj->integer.value;
>> +			else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
>> 9)
>> +				size = pobj->integer.value;
>> +			else if (type == HPWMI_ENUMERATION_TYPE && i
>> == 10)
>> +				size = pobj->integer.value;
>> +			else if (type == HPWMI_PASSWORD_TYPE && i ==
>> 11)
>> +				size = pobj->integer.value;
>> +
>> +			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
>> %lld,\n", buf,
>> +					    hp_wmi_elements[type][i], pobj-
>>> integer.value);
>> +		}
>> +	}
>> +
>> +	if (type == HPWMI_ENUMERATION_TYPE) {
>> +		buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\":
>> [\n", buf);
>> +		for (i = 0; i < size; i++) {
>> +			pobj = &(obj->package.elements[i +
>> hp_wmi_elements_count[type]]);
>> +
>> +			status = convert_hexstr_to_str(&pobj-
>>> string.pointer,
>> +						       pobj->string.length,
>> +						       &value, &value_len);
>> +			if (ACPI_FAILURE(status))
>> +				break;
>> +
>> +			/*
>> +			 * Report list of "PossibleValues" of size
>> +			 * "Size"
>> +			 *	...
>> +			 *	"Size": 2,
>> +			 *	"PossibleValues": [
>> +			 *			"Disable",
>> +			 *			"Enable"]
>> +			 */
>> +			if (i == (size - 1))
>> +				buf_size = snprintf(buf, alloc_size,
>> +						    "%s\t\t\"%s\"\n", buf,
>> value);
>> +			else
>> +				buf_size = snprintf(buf, alloc_size,
>> +						    "%s\t\t\"%s\",\n", buf,
>> value);
>> +			kfree(value);
>> +			value = NULL;
>> +		}
>> +		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>> +	}
>> +
>> +	if (type == HPWMI_ORDEREDLIST_TYPE) {
>> +		buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n",
>> buf);
>> +		if (size <= 0)
>> +			goto finish_ordered_list;
>> +
>> +		pobj = &(obj-
>>> package.elements[hp_wmi_elements_count[type]]);
>> +		status = convert_hexstr_to_str(&pobj->string.pointer,
>> +					       pobj->string.length, &value,
>> &value_len);
>> +		if (ACPI_FAILURE(status))
>> +			goto finish_ordered_list;
>> +
>> +		/*
>> +		 * Ordered list data is stored in hex and comma separated
>> format
>> +		 * Convert the data and split it to show each element
>> +		 */
>> +		status = convert_hexstr_to_str(&value, value_len, &tmpstr,
>> &tmp_len);
>> +		if (ACPI_FAILURE(status))
>> +			goto finish_ordered_list;
>> +
>> +		part_tmp = tmpstr;
>> +		part = strsep(&part_tmp, ",");
>> +		while (part) {
>> +			buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"",
>> buf, part);
>> +			part = strsep(&part_tmp, ",");
>> +			if (part)
>> +				buf_size = snprintf(buf, alloc_size, "%s,\n",
>> buf);
>> +			else
>> +				buf_size = snprintf(buf, alloc_size, "%s\n",
>> buf);
>> +		}
>> +	}
>> +
>> +finish_ordered_list:
>> +	if (type == HPWMI_ORDEREDLIST_TYPE)
>> +		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>> +
>> +	/*
>> +	 * remove trailing comma
>> +	 */
>> +	if (buf_size > 3)
>> +		buf[buf_size - 2] = ' ';
>> +
>> +	kfree(tmpstr);
>> +	kfree(value);
>> +	return snprintf(buf, alloc_size, "%s},\n", buf);
>> +}
>> +
>> +static int append_buffer_elements_to_buffer(union acpi_object *obj,
>> +					    char *buf, int alloc_size, enum
>> hp_wmi_data_type type)
>> +{
>> +	int buf_size;
>> +	int status;
>> +	char *str = NULL;
>> +	int i;
>> +	int j;
>> +	int integer;
>> +	int size = 0;
>> +
>> +	if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
>> +		return -EINVAL;
>> +
>> +	if (obj->type != ACPI_TYPE_BUFFER)
>> +		return -EINVAL;
>> +
>> +	buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
>> +	buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
>> hp_wmi_classes[type]);
>> +
>> +	for (i = 0; i < 3; i++) {
>> +		status = get_string_from_buffer((u16 **)&obj-
>>> buffer.pointer, &str);
>> +		if (ACPI_SUCCESS(status)) {
>> +			/*
>> +			 * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
>> since
>> +			 * 'CurrentValue' is reported.
>> +			 */
>> +			if (type != HPWMI_ENUMERATION_TYPE || i != 1)
>> +				buf_size = snprintf(buf, alloc_size,
>> +						    "%s\t\"%s\": \"%s\",\n",
>> +						    buf,
>> +
>> hp_wmi_elements[type][i], str);
>> +		}
>> +		kfree(str);
>> +		str = NULL;
>> +
>> +	}
>> +
>> +	for (i = 3; i < hp_wmi_elements_count[type]; i++) {
>> +		if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
>> +			status = get_string_from_buffer((u16 **)&obj-
>>> buffer.pointer, &str);
>> +			if (ACPI_SUCCESS(status)) {
>> +				/*
>> +				 * Report "CurrentValue" as "Value"
>> +				 */
>> +				buf_size = snprintf(buf, alloc_size,
>> +						    "%s\t\"Value\": \"%s\",\n",
>> buf, str);
>> +			}
>> +			kfree(str);
>> +			str = NULL;
>> +			continue;
>> +
>> +		} else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
>> +			/*
>> +			 * Report list of "SupportEncoding"
>> +			 *
>> +			 *	"SupportedEncoding": [
>> +			 *		"utf-16"
>> +			 *	],
>> +			 *
>> +			 */
>> +
>> +			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
>> +					    buf, hp_wmi_elements[type][i]);
>> +			for (j = 0; j < size; j++) {
>> +				status = get_string_from_buffer((u16
>> **)&obj->buffer.pointer, &str);
>> +				if (ACPI_SUCCESS(status)) {
>> +					if (j == size - 1)
>> +						buf_size = snprintf(buf,
>> alloc_size,
>> +
>> "%s\t\t\"%s\"\n", buf, str);
>> +					else
>> +						buf_size = snprintf(buf,
>> alloc_size,
>> +
>> "%s\t\t\"%s\",\n", buf, str);
>> +				}
>> +				kfree(str);
>> +				str = NULL;
>> +			}
>> +			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>> +			continue;
>> +		}
>> +
>> +		size = 0;
>> +		status = get_integer_from_buffer((int **)&obj-
>>> buffer.pointer, &integer);
>> +		if (ACPI_SUCCESS(status)) {
>> +			/*
>> +			 * Report "PrerequisiteSize" and "Size" values
>> +			 *	...
>> +			 *	"PrerequisiteSize": 1,
>> +			 *	...
>> +			 *	"Size": 2,
>> +			 *	...
>> +			 */
>> +			if (i == 7)
>> +				size = integer;
>> +			else if (type == HPWMI_ENUMERATION_TYPE && i
>> == 10)
>> +				size = integer;
>> +			else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
>> 9)
>> +				size = integer;
>> +			else if (type == HPWMI_PASSWORD_TYPE && i ==
>> 11)
>> +				size = integer;
>> +
>> +			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
>> %d,\n", buf,
>> +					    hp_wmi_elements[type][i],
>> integer);
>> +		}
>> +
>> +		if (size > 20)
>> +			pr_warn("%s exceeded the maximum number of
>> elements supported or data may be malformed\n",
>> +				hp_wmi_elements[type][i]);
>> +
>> +		if (ACPI_SUCCESS(status) && i == 7) {
>> +			buf_size = snprintf(buf, alloc_size,
>> "%s\t\"Prerequisites\": [\n", buf);
>> +			for (j = 0; j < size; j++) {
>> +				status = get_string_from_buffer((u16
>> **)&obj->buffer.pointer, &str);
>> +				if (ACPI_SUCCESS(status)) {
>> +					buf_size = snprintf(buf, alloc_size,
>> "%s\t\t\"%s\"", buf, str);
>> +
>> +					if (j == size - 1)
>> +						buf_size = snprintf(buf,
>> alloc_size, "%s\n", buf);
>> +					else
>> +						buf_size = snprintf(buf,
>> alloc_size, "%s,\n", buf);
>> +
>> +				}
>> +				kfree(str);
>> +				str = NULL;
>> +			}
>> +			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>> +		}
>> +	}
>> +
>> +	if (type == HPWMI_ENUMERATION_TYPE || type ==
>> HPWMI_ORDEREDLIST_TYPE) {
>> +		if (type == HPWMI_ENUMERATION_TYPE)
>> +			buf_size = snprintf(buf, alloc_size,
>> "%s\t\"PossibleValues\": [\n", buf);
>> +		else
>> +			buf_size = snprintf(buf, alloc_size,
>> "%s\t\"Elements\": [\n", buf);
>> +
>> +		for (i = 0; i < size; i++) {
>> +			status = get_string_from_buffer((u16 **)&obj-
>>> buffer.pointer, &str);
>> +			if (ACPI_SUCCESS(status)) {
>> +				buf_size = snprintf(buf, alloc_size,
>> "%s\t\t\"%s\"", buf, str);
>> +
>> +				if (i == size - 1)
>> +					buf_size = snprintf(buf, alloc_size,
>> "%s\n", buf);
>> +				else
>> +					buf_size = snprintf(buf, alloc_size,
>> "%s,\n", buf);
>> +
>> +			}
>> +			kfree(str);
>> +			str = NULL;
>> +		}
>> +		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>> +	}
>> +
>> +	/*
>> +	 * remove trailing comma
>> +	 */
>> +	if (buf_size > 3)
>> +		buf[buf_size - 2] = ' ';
>> +
>> +	return snprintf(buf, alloc_size, "%s},\n", buf);
>> +}
>> +
>> +static int hp_bios_settings_free_buffer(void)
>> +{
>> +	mutex_lock(&buf_mutex);
>> +	kfree(hp_bios_settings_buffer);
>> +	settings_buffer_size = 0;
>> +	buf_alloc_size = 0;
>> +	mutex_unlock(&buf_mutex);
>> +
>> +	return 0;
>> +}
>> +
>> +static int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
>> +					   int *alloc_size,
>> +					   struct mutex *buf_mutex)
>> +{
>> +	int new_buffer_size;
>> +	char *new_buf = NULL;
>> +	int ret = 0;
>> +
>> +	if (*buf_size + PAGE_SIZE >= *alloc_size) {
>> +		new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
>> +
>> +		mutex_lock(buf_mutex);
>> +		new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
>> +		mutex_unlock(buf_mutex);
>> +		if (new_buf) {
>> +			mutex_lock(buf_mutex);
>> +			*buf = new_buf;
>> +			*alloc_size = ksize(new_buf);
>> +			mutex_unlock(buf_mutex);
>> +		} else {
>> +			hp_bios_settings_free_buffer();
>> +			ret = -ENOMEM;
>> +		}
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int append_settings_to_buffer(char *guid, int type, char **buf,
>> +				     int *buf_size, int *alloc_size,
>> +				     struct mutex *buf_mutex)
>> +{
>> +	union acpi_object *obj = NULL;
>> +	int ret = 0;
>> +	int status = 0;
>> +	int instance = 0;
>> +
>> +	/*
>> +	 * Query all the instances until to receive a AE_BAD_PARAMETER
>> +	 */
>> +	do {
>> +		ret = hp_wmi_get_setting_object(guid, instance++, &obj);
>> +		if (ACPI_SUCCESS(ret) && obj != NULL) {
>> +			status = 0;
>> +			if (obj->type == ACPI_TYPE_PACKAGE) {
>> +				mutex_lock(buf_mutex);
>> +				status =
>> append_package_elements_to_buffer(obj,
>> +							*buf, *alloc_size,
>> type);
>> +				if (status > 0)
>> +					*buf_size = status;
>> +				mutex_unlock(buf_mutex);
>> +
>> +			} else if (obj->type == ACPI_TYPE_BUFFER) {
>> +				mutex_lock(buf_mutex);
>> +				status =
>> append_buffer_elements_to_buffer(obj,
>> +							*buf, *alloc_size,
>> type);
>> +				if (status > 0)
>> +					*buf_size = status;
>> +				mutex_unlock(buf_mutex);
>> +
>> +			} else
>> +				pr_warn("The retrieved object type(%d) is
>> not supported yet\n",
>> +					obj->type);
>> +
>> +			ret = hp_bios_settings_realloc_buffer(buf, buf_size,
>> alloc_size, buf_mutex);
>> +		}
>> +
>> +		kfree(obj);
>> +		obj = NULL;
>> +
>> +	} while (ACPI_SUCCESS(ret));
>> +
>> +	/*
>> +	 * AE_BAD_PARAMETER means the loop ended by exhaustion
>> +	 */
>> +	if (ret == AE_BAD_PARAMETER)
>> +		ret = 0;
>> +
>> +	return ret;
>> +}
>> +
>> +static int hp_bios_settings_fill_buffer(void)
>> +{
>> +	int status = 0;
>> +	int initial_buffer_size = 20 * PAGE_SIZE;
>> +
>> +	mutex_lock(&buf_mutex);
>> +	hp_bios_settings_buffer = kmalloc(initial_buffer_size, GFP_KERNEL);
>> +	mutex_unlock(&buf_mutex);
>> +	if (!hp_bios_settings_buffer)
>> +		return -ENOMEM;
>> +
>> +	mutex_lock(&buf_mutex);
>> +	buf_alloc_size = ksize(hp_bios_settings_buffer);
>> +	settings_buffer_size = snprintf(hp_bios_settings_buffer,
>> +					buf_alloc_size, "[\n");
>> +	mutex_unlock(&buf_mutex);
>> +
>> +	status = append_settings_to_buffer(HPWMI_STRING_GUID,
>> +		HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
>> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
>> +	if (ACPI_FAILURE(status))
>> +		pr_err("error 0x%x occurred retrieving string instances\n",
>> status);
>> +
>> +	status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
>> +		HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
>> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
>> +	if (ACPI_FAILURE(status))
>> +		pr_err("error 0x%x occurred retrieving integer instances\n",
>> status);
>> +
>> +	status = append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
>> +		HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
>> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
>> +	if (ACPI_FAILURE(status))
>> +		pr_err("error 0x%x occurred retrieving enumeration
>> instances\n", status);
>> +
>> +	status = append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
>> +		HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
>> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
>> +	if (ACPI_FAILURE(status))
>> +		pr_err("error 0x%x occurred retrieving ordered list
>> instances\n", status);
>> +
>> +	status = append_settings_to_buffer(HPWMI_PASSWORD_GUID,
>> +		HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
>> +		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
>> +	if (ACPI_FAILURE(status))
>> +		pr_err("error 0x%x occurred retrieving password list
>> instances\n", status);
>> +
>> +	mutex_lock(&buf_mutex);
>> +	/*
>> +	 * remove trailing comma
>> +	 */
>> +	if (settings_buffer_size >= 3) {
>> +		if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
>> +			hp_bios_settings_buffer[settings_buffer_size - 2] = '
>> ';
>> +	}
>> +	settings_buffer_size = snprintf(hp_bios_settings_buffer,
>> +					buf_alloc_size, "%s]\n",
>> +					hp_bios_settings_buffer);
>> +	mutex_unlock(&buf_mutex);
>> +
>> +	return settings_buffer_size;
>> +}
>> +
>> +/*
>> + * sure_admin_settings_read - Return a formatted file with settings
>> + *                              and possible options read from BIOS
>> + *
>> + * @filp:  Pointer to file of settings read from BIOS
>> + * @kobj:  Pointer to a kernel object of things that show up as directory in
>> the sysfs filesystem.
>> + * @attr:  Pointer to list of read attributes
>> + * @buf:   Pointer to buffer
>> + * @off:   File current offset
>> + * @count: Buffer size
>> + *
>> + * Returns the count of unicode chars read if successful, otherwise
>> + *		-ENOMEM unable to allocate memory
>> + *		-EINVAL buffer not allocated or too small
>> + *
>> + */
>> +static ssize_t sure_admin_settings_read(struct file *filp, struct kobject
>> *kobj,
>> +					struct bin_attribute *attr, char *buf,
>> loff_t off, size_t count)
>> +{
>> +	ssize_t ret;
>> +
>> +	/* clear the buffer when offset is pointing to the last position */
>> +	if (off >= settings_buffer_size && settings_buffer_size > 0) {
>> +		hp_bios_settings_free_buffer();
>> +		return 0;
>> +	}
>> +
>> +	/* clear the buffer whenever the read starts from the first position
>> */
>> +	if (off == 0 && settings_buffer_size > 0)
>> +		hp_bios_settings_free_buffer();
>> +
>> +	if (settings_buffer_size == 0)
>> +		hp_bios_settings_fill_buffer();
>> +
>> +	mutex_lock(&buf_mutex);
>> +	ret = memory_read_from_buffer(buf, count, &off,
>> hp_bios_settings_buffer,
>> +				      settings_buffer_size);
>> +	mutex_unlock(&buf_mutex);
>> +
>> +	return ret;
>> +}
>> +
>> +
>> +/*
>> + * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
>> + *
>> + * @p:   Unicode buffer address
>> + * @str: string to convert to unicode
>> + *
>> + * Returns a void pointer to the buffer containing unicode string
>> + */
>> +static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
>> +{
>> +	int len = strlen(str);
>> +
>> +	/*
>> +	 * Add null character when reading an empty string
>> +	 */
>> +	if (len == 0) {
>> +		*p++ = 2;
>> +		*p++ = (u8)0x00;
>> +		return p;
>> +	}
>> +	*p++ = len * 2;
>> +	utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
>> +	p += len;
>> +
>> +	return p;
>> +}
>> +
>> +/*
>> + * hp_wmi_set_bios_setting - Set setting's value in BIOS
>> + *
>> + * @input_buffer: Input buffer address
>> + * @input_size:   Input buffer size
>> + *
>> + * Returns: Count of unicode characters written to BIOS if successful,
>> otherwise
>> + *		-ENOMEM unable to allocate memory
>> + *		-EINVAL buffer not allocated or too small
>> + */
>> +static int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
>> +{
>> +	union acpi_object *obj;
>> +	struct acpi_buffer input = {input_size, input_buffer};
>> +	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
>> +	int ret = 0;
>> +
>> +	ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID, 0, 1,
>> &input, &output);
>> +
>> +	obj = output.pointer;
>> +	if (!obj)
>> +		return -EINVAL;
>> +
>> +	if (obj->type != ACPI_TYPE_INTEGER)
>> +		ret = -EINVAL;
>> +
>> +	ret = obj->integer.value;
>> +	kfree(obj);
>> +	return ret;
>> +}
>> +
>> +/* Sure Admin Functions */
>> +
>> +#define UTF_PREFIX			((unsigned char *)"<utf-16/>")
>> +#define BEAM_PREFIX			((unsigned char
>> *)"<BEAM/>")
>> +
>> +/*
>> + * sure_admin_settings_write - Write the contents of a formatted file
>> + *                               with settings and performs the logic
>> + *                               to change any settings in BIOS.
>> + *
>> + * @filp:  Pointer to file of settings to be written to BIOS
>> + * @kobj:  Pointer to a kernel object of things that show up as directory in
>> the sysfs filesystem.
>> + * @attr:  Pointer to list of attributes for the write operation
>> + * @buf:   Pointer to buffer
>> + * @off:   File current offset
>> + * @count: Buffer size
>> + *
>> + *
>> + * Returns the count of unicode characters written to BIOS if successful,
>> otherwise
>> + *		-ENOMEM unable to allocate memory
>> + *		-EINVAL buffer not allocated or too small
>> + *
>> + */
>> +static ssize_t sure_admin_settings_write(struct file *filp, struct kobject
>> *kobj,
>> +			struct bin_attribute *attr, char *buf, loff_t off, size_t
>> count)
>> +{
>> +	int status = 0;
>> +	char *part = NULL;
>> +	int part_len = 0;
>> +	unsigned short *buffer = NULL;
>> +	unsigned short *tmpstr = NULL;
>> +	int buffer_size = (count + strlen(UTF_PREFIX)) * sizeof(unsigned
>> short);
>> +
>> +	buffer = kmalloc(buffer_size, GFP_KERNEL);
>> +	if (!buffer)
>> +		return -ENOMEM;
>> +
>> +	tmpstr = buffer;
>> +	part = strsep(&buf, ",");
>> +	if (!part) {
>> +		status = -EINVAL;
>> +		goto out_free;
>> +	}
>> +	tmpstr = ascii_to_utf16_unicode(tmpstr, part);
>> +	part = strsep(&buf, ",");
>> +	if (!part) {
>> +		status = -EINVAL;
>> +		goto out_free;
>> +	}
>> +
>> +	/* Add extra buffer space when encountering an empty string */
>> +	if (!strlen(part))
>> +		buffer_size += sizeof(unsigned short);
>> +	tmpstr = ascii_to_utf16_unicode(tmpstr, part);
>> +	part = strsep(&buf, ",");
>> +	if (!part) {
>> +		status = -EINVAL;
>> +		goto out_free;
>> +	}
>> +	part_len = strlen(part) - 1;
>> +	part[part_len] = '\0';
>> +
>> +	if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
>> +	       /*
>> +		* BEAM_PREFIX is append to buffer when a signature
>> +		* is provided and Sure Admin is enabled in BIOS
>> +		*/
>> +		// BEAM_PREFIX found, convert part to unicode
>> +		tmpstr = ascii_to_utf16_unicode(tmpstr, part);
>> +		// decrease buffer size allocated initially for UTF_PREFIX
>> +		buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
>> +	} else {
>> +		/*
>> +		 * UTF-16 prefix is append to the * buffer when a BIOS
>> +		 * admin password is configured in BIOS
>> +		 */
>> +
>> +		// append UTF_PREFIX to part and then convert it to unicode
>> +		part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
>> +		if (!part)
>> +			goto out_free;
>> +
>> +		tmpstr = ascii_to_utf16_unicode(tmpstr, part);
>> +		kfree(part);
>> +	}
>> +
>> +	part = strsep(&buf, ",");
>> +	if (part) {
>> +		status = -EINVAL;
>> +		goto out_free;
>> +	}
>> +	status = hp_wmi_set_bios_setting(buffer, buffer_size);
>> +	if (ACPI_FAILURE(status))
>> +		status = -EINVAL;
>> +
>> +out_free:
>> +	kfree(buffer);
>> +	if (ACPI_SUCCESS(status))
>> +		return count;
>> +	return status;
>> +}
>> +
>> +HPWMI_BINATTR_RW(sure_admin, settings, 0);
>> +
>> +static struct bin_attribute *sure_admin_binattrs[] = {
>> +	&sure_admin_settings,
>> +	NULL,
>> +};
>> +
>> +static const struct attribute_group sure_admin_group = {
>> +	.name = "sure_admin",
>> +	.bin_attrs = sure_admin_binattrs,
>> +};
>> +
>>  static DEVICE_ATTR_RO(display);
>>  static DEVICE_ATTR_RO(hddtemp);
>>  static DEVICE_ATTR_RW(als);
>> @@ -1050,6 +2026,7 @@ static const struct attribute_group
>> *hp_wmi_groups[] = {
>>  	&hp_wmi_group,
>>  	&spm_group,
>>  	&sure_start_group,
>> +	&sure_admin_group,
>>  	NULL,
>>  };
>>
>> --
>> 2.25.1

Jorge Lopez April 5, 2022, 4:52 p.m. UTC | #3

Hi Hans,

On Tue, Apr 5, 2022 at 6:54 AM Hans de Goede <[e-mail]> wrote:
>
> Hi,
>
> On 4/4/22 23:59, Limonciello, Mario wrote:
> > [Public]
> >
> >
> >
> >> -----Original Message-----
> >> From: Jorge Lopez <[e-mail]>
> >> Sent: Monday, April 4, 2022 15:36
> >> To: [e-mail]
> >> Subject: [PATCH v1 5/6] Sure Admin Security Feature
> >>
> >> HP Commercial PC’s have several BIOS settings that control its
> >> behaviour and capabilities, many of which are related to security.  To
> >> prevent unauthorized changes to these settings, the system can be
> >> configured to use a Sure Admin cryptographic signature-based
> >> authorization string that the BIOS will use to verify authorization to
> >> modify the setting. Behind the scenes, Sure Admin uses Secure Platform
> >> Management (SPM) and WMI
> >>
> >> 'settings' is a file associated with Sure Admin. BIOS settings can be
> >> read or written through the Sure Admin settings file in sysfs
> >>
> >>      /sys/devices/platform/hp-wmi/sure_admin/settings
> >>
> >> Expected data format to update BIOS setting
> >>
> >>      [BIOS setting],[new value],[auth token]
> >>
> >> Sample settings reported data
> >>
> >>      {
> >>              "Class": "HPBIOS_BIOSEnumeration",
> >>              "Name": "USB Storage Boot",
> >>              "Path": "\\Advanced\\Boot Options",
> >>              "IsReadOnly": 0,
> >>              ...
> >>              "Value": "Enable",
> >>              "Size": 2,
> >>              "PossibleValues": [
> >>                      "Disable",
> >>                      "Enable"
> >>              ]
> >>      }
> >>
> >
> > This sounds like it has re-invented /sys/class/firmware-attributes.
> >
> > Shouldn't you adopt that API?
>
> I fully agree. Jorge as I already indicated in our off-list
> conversation when you initially started working on this
> feature, we already have a standardized API for querying/changing
> BIOS settings from within Linux:
>

I agree that changing the BIOS settings from within Linux could
utilize the new methodology,  I will need to look closely at the
requirements before I can proceed to make the changes.
Keep in mind authentication of the values is done by BIOS.  No Linux
process validates any data name, value, or auth token; only BIOS.  All
data written to the sysfs file is not validated, it is just forward to
BIOS.  See spm_kek_store and spm_sk_store functions.
One point I must make clear when updating BIOS settings.  any  NOT
read-only BIOS settings can be changed by the application at any time.
   This list of settings changes from one system to another.

I am in disagreement with reading the settings.  hp-wmi does not read
one value at a time. It reads all values exposed by BIOS.  See
attached sample output.
The method for how all BIOS settings are reported needs to match the
method how Windows products do it.  It is a requirement to start
migrating customers from Windows to Linux while minimizing how BIOS
data is reported.

I will investigate the new API and bring it to the team's attention.

> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-class-firmware-attributes
>
> and any new code (such as this patch) which implements BIOS
> setting changing MUST follow this standardized API (extending
> it where necessary).
>
> I'm sorry but this patch is not acceptable in its current form,
> it needs to be *completely rewritten* to implement:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-class-firmware-attributes
>
> See:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/platform/x86/dell/dell-wmi-sysman
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/platform/x86/think-lmi.c
>
> for example code / for 2 drivers from other vendors already
> implementing this.
>
> The same applies to the:
>
> "[PATCH v1 3/6] Secure Platform Management Security Feature"
>
> this needs to be implemented as
> a /sys/class/firmware-attributes/*/authentication/
> authentication method, see for example these Lenovo specific
> addition to the /sys/class/firmware-attributes/*/authentication/
> userspace API for similar functionality on Lenovo Think* devices:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=06384573a3e8335ac6797577e545c33dbf91b490
>
> I'll merge patches 1-2 sometime this week since those are
> fine and it will be good to have those "out of the way",
> but the rest of the series will need to be rewritten
> taken the above comments into account.

v1-0003-Sure-Start-Security-Feature.patch  reports the number of audit
logs available and reports them when read.    it does not read/write
BIOS settings hence it does not fall within the same category as
patches v1-0002-Secure-Platform-Management-Security-Feature.patch and
v1-0004-Sure-Admin-Security-Feature.patch
Do you agree?

>
> Regards,
>
> Hans
>
>
>
>
>
>
>
>
>
>
> >
> >> This feature requires "Update hp_wmi_group to simplify feature
> >> addition" patch.
> >>
> >> All changes were validated on a HP ZBook Workstation,
> >> HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
> >>
> >> Signed-off-by: Jorge Lopez <[e-mail]>
> >>
> >> ---
> >> Based on the latest platform-drivers-x86.git/for-next
> >> ---
> >>  drivers/platform/x86/hp-wmi.c | 977
> >> ++++++++++++++++++++++++++++++++++
> >>  1 file changed, 977 insertions(+)
> >>
> >> diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
> >> index 918e3eaf1b67..b72ca18b77a6 100644
> >> --- a/drivers/platform/x86/hp-wmi.c
> >> +++ b/drivers/platform/x86/hp-wmi.c
> >> @@ -27,6 +27,7 @@
> >>  #include <linux/rfkill.h>
> >>  #include <linux/string.h>
> >>  #include <linux/dmi.h>
> >> +#include <linux/nls.h>
> >>
> >>  MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
> >>  MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
> >> @@ -37,8 +38,16 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-
> >> 3D44E2C707E4");
> >>
> >>  #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-ACCDC67EF61C"
> >>  #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-3D44E2C707E4"
> >> +
> >>  #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
> >>
> >> +#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-6A1B8106F83C"
> >> +#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-
> >> E293ADB9BF05"
> >> +#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-
> >> 4A3C09E75133"
> >> +#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-A0E0-
> >> 7045CB4DA745"
> >> +#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-
> >> 015176049E2D"
> >> +#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-951D-
> >> C7CB9B4B8D5E"
> >> +
> >>  /* DMI board names of devices that should use the omen specific path for
> >>   * thermal profiles.
> >>   * This was obtained by taking a look in the windows omen command center
> >> @@ -1025,6 +1034,973 @@ static const struct attribute_group
> >> sure_start_group = {
> >>      .attrs = sure_start_attrs,
> >>  };
> >>
> >> +
> >> +static int convert_hexstr_to_str(char **hex, int input_len, char **str, int
> >> *len)
> >> +{
> >> +    int ret = 0;
> >> +    int new_len = 0;
> >> +    char tmp[] = "0x00";
> >> +    char *input = *hex;
> >> +    char *new_str = NULL;
> >> +    int  ch;
> >> +    int i;
> >> +
> >> +    if (input_len <= 0 || hex == NULL || str == NULL || len == NULL)
> >> +            return -EINVAL;
> >> +
> >> +    *len = 0;
> >> +    *str = NULL;
> >> +
> >> +    new_str = kmalloc(input_len, GFP_KERNEL);
> >> +    if (!new_str)
> >> +            return -ENOMEM;
> >> +
> >> +    for (i = 0; i < input_len; i += 5) {
> >> +            strncpy(tmp, input + i, strlen(tmp));
> >> +            ret = kstrtoint(tmp, 16, &ch);
> >> +            if (ret) {
> >> +                    new_len = 0;
> >> +                    break;
> >> +            }
> >> +
> >> +            if (ch == '\\')
> >> +                    new_str[new_len++] = '\\';
> >> +
> >> +            new_str[new_len++] = ch;
> >> +            if (ch == '\0')
> >> +                    break;
> >> +    }
> >> +
> >> +    if (new_len) {
> >> +            new_str[new_len] = '\0';
> >> +            *str = krealloc(new_str, (new_len + 1) * sizeof(char),
> >> GFP_KERNEL);
> >> +            if (*str)
> >> +                    *len = new_len;
> >> +            else
> >> +                    ret = -ENOMEM;
> >> +    }
> >> +
> >> +    if (ret)
> >> +            kfree(new_str);
> >> +    return ret;
> >> +}
> >> +
> >> +/*
> >> + * hp_wmi_get_setting_object() - Get an ACPI object by GUID and instance
> >> + *
> >> + * @guid:   GUID associated with the ACPI list of managed objects
> >> + * @instance:       Instance index to query on the ACPI list
> >> + * @obj:    The output ACPI object of type ACPI_TYPE_PACKAGE
> >> + *          or ACPI_TYPE_BUFFER (freed by the callee)
> >> + *
> >> + * Returns  zero on success.  Otherwise,an error inherited from
> >> + *          wmi_query_block(). It returns a obj by parameter if
> >> + *          the query returned object of type buffer or package,
> >> + *          otherwise, a null obj is returned.
> >> + *
> >> + * Note: obj should be freed by the callee once it is finished working with it
> >> + */
> >> +static int hp_wmi_get_setting_object(char *guid, int instance,
> >> +                            union acpi_object **obj)
> >> +{
> >> +    struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER, NULL
> >> };
> >> +    union acpi_object *tmp = NULL;
> >> +    int ret;
> >> +
> >> +    ret = wmi_query_block(guid, instance, &output);
> >> +    if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
> >> +            tmp = output.pointer;
> >> +            if (tmp->type == ACPI_TYPE_BUFFER || tmp->type ==
> >> ACPI_TYPE_PACKAGE)
> >> +                    *obj = output.pointer;
> >> +            else {
> >> +                    kfree(tmp);
> >> +                    *obj = NULL;
> >> +            }
> >> +    }
> >> +
> >> +    return ret;
> >> +}
> >> +
> >> +
> >> +static int get_string_from_buffer(u16 **buffer, char **str)
> >> +{
> >> +    u16 *ptr = *buffer;
> >> +    u16 ptrlen;
> >> +
> >> +    u16 size;
> >> +    int i;
> >> +    char *output = NULL;
> >> +    int escape = 0;
> >> +
> >> +    ptrlen = *(ptr++);
> >> +    size = ptrlen / 2;
> >> +
> >> +    if (size == 0)
> >> +            goto cleanup_exit;
> >> +
> >> +    for (i = 0; i < size; i++)
> >> +            if (ptr[i] == '\\')
> >> +                    escape++;
> >> +
> >> +    size += escape;
> >> +    *str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
> >> +    if (!*str)
> >> +            return -ENOMEM;
> >> +
> >> +    output = *str;
> >> +
> >> +    /*
> >> +     * convert from UTF-16 unicode to ASCII
> >> +     */
> >> +    utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output, size);
> >> +
> >> +    if (escape == 0) {
> >> +            ptr += (ptrlen / 2);
> >> +            goto cleanup_exit;
> >> +    }
> >> +    /*
> >> +     * Convert escape characters only when found
> >> +     */
> >> +    for (i = 0; i < size; i++) {
> >> +            if (*ptr == '\\')
> >> +                    output[i++] = '\\';
> >> +            output[i] = *ptr;
> >> +            ptr++;
> >> +    }
> >> +
> >> +cleanup_exit:
> >> +    *buffer = ptr;
> >> +    return 0;
> >> +}
> >> +
> >> +static int get_integer_from_buffer(int **buffer, int *integer)
> >> +{
> >> +    int *ptr = PTR_ALIGN(*buffer, 4);
> >> +    *integer = *(ptr++);
> >> +    *buffer = ptr;
> >> +    return 0;
> >> +}
> >> +
> >> +
> >> +// Sure Admin functions
> >> +enum hp_wmi_data_type {
> >> +    HPWMI_STRING_TYPE,
> >> +    HPWMI_INTEGER_TYPE,
> >> +    HPWMI_ENUMERATION_TYPE,
> >> +    HPWMI_ORDEREDLIST_TYPE,
> >> +    HPWMI_PASSWORD_TYPE,
> >> +};
> >> +
> >> +#define HP_WMI_COMMON_ELEMENTS      \
> >> +    "Name", \
> >> +    "Value",        \
> >> +    "Path", \
> >> +    "IsReadOnly",   \
> >> +    "DisplayInUI",  \
> >> +    "RequiresPhysicalPresence",     \
> >> +    "Sequence",     \
> >> +    "PrerequisiteSize",     \
> >> +    "SecurityLevel"
> >> +
> >> +const char *hp_wmi_string_elements[] = {
> >> +    HP_WMI_COMMON_ELEMENTS,
> >> +    "MinLength",
> >> +    "MaxLength"
> >> +};
> >> +
> >> +const char *hp_wmi_integer_elements[] = {
> >> +    HP_WMI_COMMON_ELEMENTS,
> >> +    "LowerBound",
> >> +    "UpperBound",
> >> +    "IntValue"
> >> +};
> >> +
> >> +const char *hp_wmi_enumeration_elements[] = {
> >> +    HP_WMI_COMMON_ELEMENTS,
> >> +    "CurrentValue",
> >> +    "Size"
> >> +};
> >> +
> >> +const char *hp_wmi_orderedlist_elements[] = {
> >> +    HP_WMI_COMMON_ELEMENTS,
> >> +    "Size"
> >> +};
> >> +
> >> +const char *hp_wmi_password_elements[] = {
> >> +    HP_WMI_COMMON_ELEMENTS,
> >> +    "MinLength",
> >> +    "MaxLength",
> >> +    "Size",
> >> +    "SupportedEncoding",
> >> +    "IsSet"
> >> +};
> >> +
> >> +const char **hp_wmi_elements[] = {
> >> +    hp_wmi_string_elements,
> >> +    hp_wmi_integer_elements,
> >> +    hp_wmi_enumeration_elements,
> >> +    hp_wmi_orderedlist_elements,
> >> +    hp_wmi_password_elements
> >> +};
> >> +
> >> +const int hp_wmi_elements_count[] = {
> >> +    ARRAY_SIZE(hp_wmi_string_elements),
> >> +    ARRAY_SIZE(hp_wmi_integer_elements),
> >> +    ARRAY_SIZE(hp_wmi_enumeration_elements),
> >> +    ARRAY_SIZE(hp_wmi_orderedlist_elements),
> >> +    ARRAY_SIZE(hp_wmi_password_elements)
> >> +};
> >> +
> >> +const char *hp_wmi_classes[] = {
> >> +    "HPBIOS_BIOSString",
> >> +    "HPBIOS_BIOSInteger",
> >> +    "HPBIOS_BIOSEnumeration",
> >> +    "HPBIOS_BIOSOrderedList",
> >> +    "HPBIOS_BIOSPassword"
> >> +};
> >> +
> >> +static DEFINE_MUTEX(buf_mutex);
> >> +static int settings_buffer_size;
> >> +static int buf_alloc_size;
> >> +static char *hp_bios_settings_buffer;
> >> +
> >> +
> >> +static int append_package_elements_to_buffer(union acpi_object *obj,
> >> +                                         char *buf, int alloc_size, enum
> >> hp_wmi_data_type type)
> >> +{
> >> +    int i;
> >> +    union acpi_object *pobj = NULL;
> >> +    char *value = NULL;
> >> +    int value_len;
> >> +    char *tmpstr = NULL;
> >> +    char *part_tmp = NULL;
> >> +    int tmp_len = 0;
> >> +    char *part = NULL;
> >> +    int status = 0;
> >> +    int size = 0;
> >> +    int buf_size;
> >> +
> >> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> >> +            return -EINVAL;
> >> +
> >> +    if (obj->type != ACPI_TYPE_PACKAGE)
> >> +            return -EINVAL;
> >> +
> >> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> >> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> >> hp_wmi_classes[type]);
> >> +
> >> +    for (i = 0; i < 3; i++) {
> >> +            pobj = &(obj->package.elements[i]);
> >> +            if (pobj->type == ACPI_TYPE_STRING) {
> >> +                    status = convert_hexstr_to_str(&pobj-
> >>> string.pointer,
> >> +                                                   pobj->string.length,
> >> &value, &value_len);
> >> +                    if (ACPI_FAILURE(status))
> >> +                            continue;
> >> +                    /*
> >> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> >> since
> >> +                     * 'CurrentValue' is reported.
> >> +                     */
> >> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> >> +                            buf_size = snprintf(buf, alloc_size,
> >> +                                                "%s\t\"%s\": \"%s\",\n",
> >> +                                                buf,
> >> +
> >> hp_wmi_elements[type][i], value);
> >> +
> >> +            }
> >> +            kfree(value);
> >> +            value = NULL;
> >> +    }
> >> +
> >> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> >> +            pobj = &(obj->package.elements[i]);
> >> +
> >> +            if (type == HPWMI_ENUMERATION_TYPE &&
> >> +                i == 9 &&
> >> +                pobj->type == ACPI_TYPE_STRING) {
> >> +                    /*
> >> +                     * Report "CurrentValue" as "Value"
> >> +                     */
> >> +                    status = convert_hexstr_to_str(&pobj-
> >>> string.pointer,
> >> +                                                   pobj->string.length,
> >> +                                                   &value, &value_len);
> >> +                    if (ACPI_FAILURE(status))
> >> +                            continue;
> >> +
> >> +                    buf_size = snprintf(buf, alloc_size,
> >> +                                        "%s\t\"Value\": \"%s\",\n",
> >> +                                        buf, value);
> >> +                    kfree(value);
> >> +                    value = NULL;
> >> +
> >> +            } else if (type == HPWMI_PASSWORD_TYPE &&
> >> +                       i == 12 &&
> >> +                       pobj->type == ACPI_TYPE_STRING) {
> >> +                    /*
> >> +                     * Report list of "SupportEncoding"
> >> +                     *
> >> +                     *      "SupportedEncoding": [
> >> +                     *              "utf-16"
> >> +                     *      ],
> >> +                     *
> >> +                     */
> >> +
> >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> >> +                                        buf, hp_wmi_elements[type][i]);
> >> +                    while (size--) {
> >> +                            pobj = &(obj->package.elements[i]);
> >> +                            status = convert_hexstr_to_str(&pobj-
> >>> string.pointer,
> >> +                                                           pobj-
> >>> string.length,
> >> +                                                           &value,
> >> &value_len);
> >> +                            if (ACPI_FAILURE(status))
> >> +                                    continue;
> >> +
> >> +                            if (size) {
> >> +                                    buf_size = snprintf(buf, alloc_size,
> >> +                                                        "%s\t\t\"%s\",\n",
> >> buf, value);
> >> +                                    i++;
> >> +                            } else
> >> +                                    buf_size = snprintf(buf, alloc_size,
> >> +                                                        "%s\t\t\"%s\"\n",
> >> buf, value);
> >> +
> >> +                            kfree(value);
> >> +                            value = NULL;
> >> +
> >> +                    }
> >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >> +                    continue;
> >> +
> >> +            } else if (pobj->type == ACPI_TYPE_INTEGER) {
> >> +                    /*
> >> +                     * Report "PrerequisiteSize" and "Size" values
> >> +                     *      ...
> >> +                     *      "PrerequisiteSize": 1,
> >> +                     *      ...
> >> +                     *      "Size": 2,
> >> +                     *      ...
> >> +                     */
> >> +                    if (i == 7)
> >> +                            size = pobj->integer.value;
> >> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> >> 9)
> >> +                            size = pobj->integer.value;
> >> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> >> == 10)
> >> +                            size = pobj->integer.value;
> >> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> >> 11)
> >> +                            size = pobj->integer.value;
> >> +
> >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> >> %lld,\n", buf,
> >> +                                        hp_wmi_elements[type][i], pobj-
> >>> integer.value);
> >> +            }
> >> +    }
> >> +
> >> +    if (type == HPWMI_ENUMERATION_TYPE) {
> >> +            buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\":
> >> [\n", buf);
> >> +            for (i = 0; i < size; i++) {
> >> +                    pobj = &(obj->package.elements[i +
> >> hp_wmi_elements_count[type]]);
> >> +
> >> +                    status = convert_hexstr_to_str(&pobj-
> >>> string.pointer,
> >> +                                                   pobj->string.length,
> >> +                                                   &value, &value_len);
> >> +                    if (ACPI_FAILURE(status))
> >> +                            break;
> >> +
> >> +                    /*
> >> +                     * Report list of "PossibleValues" of size
> >> +                     * "Size"
> >> +                     *      ...
> >> +                     *      "Size": 2,
> >> +                     *      "PossibleValues": [
> >> +                     *                      "Disable",
> >> +                     *                      "Enable"]
> >> +                     */
> >> +                    if (i == (size - 1))
> >> +                            buf_size = snprintf(buf, alloc_size,
> >> +                                                "%s\t\t\"%s\"\n", buf,
> >> value);
> >> +                    else
> >> +                            buf_size = snprintf(buf, alloc_size,
> >> +                                                "%s\t\t\"%s\",\n", buf,
> >> value);
> >> +                    kfree(value);
> >> +                    value = NULL;
> >> +            }
> >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >> +    }
> >> +
> >> +    if (type == HPWMI_ORDEREDLIST_TYPE) {
> >> +            buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n",
> >> buf);
> >> +            if (size <= 0)
> >> +                    goto finish_ordered_list;
> >> +
> >> +            pobj = &(obj-
> >>> package.elements[hp_wmi_elements_count[type]]);
> >> +            status = convert_hexstr_to_str(&pobj->string.pointer,
> >> +                                           pobj->string.length, &value,
> >> &value_len);
> >> +            if (ACPI_FAILURE(status))
> >> +                    goto finish_ordered_list;
> >> +
> >> +            /*
> >> +             * Ordered list data is stored in hex and comma separated
> >> format
> >> +             * Convert the data and split it to show each element
> >> +             */
> >> +            status = convert_hexstr_to_str(&value, value_len, &tmpstr,
> >> &tmp_len);
> >> +            if (ACPI_FAILURE(status))
> >> +                    goto finish_ordered_list;
> >> +
> >> +            part_tmp = tmpstr;
> >> +            part = strsep(&part_tmp, ",");
> >> +            while (part) {
> >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"",
> >> buf, part);
> >> +                    part = strsep(&part_tmp, ",");
> >> +                    if (part)
> >> +                            buf_size = snprintf(buf, alloc_size, "%s,\n",
> >> buf);
> >> +                    else
> >> +                            buf_size = snprintf(buf, alloc_size, "%s\n",
> >> buf);
> >> +            }
> >> +    }
> >> +
> >> +finish_ordered_list:
> >> +    if (type == HPWMI_ORDEREDLIST_TYPE)
> >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >> +
> >> +    /*
> >> +     * remove trailing comma
> >> +     */
> >> +    if (buf_size > 3)
> >> +            buf[buf_size - 2] = ' ';
> >> +
> >> +    kfree(tmpstr);
> >> +    kfree(value);
> >> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> >> +}
> >> +
> >> +static int append_buffer_elements_to_buffer(union acpi_object *obj,
> >> +                                        char *buf, int alloc_size, enum
> >> hp_wmi_data_type type)
> >> +{
> >> +    int buf_size;
> >> +    int status;
> >> +    char *str = NULL;
> >> +    int i;
> >> +    int j;
> >> +    int integer;
> >> +    int size = 0;
> >> +
> >> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> >> +            return -EINVAL;
> >> +
> >> +    if (obj->type != ACPI_TYPE_BUFFER)
> >> +            return -EINVAL;
> >> +
> >> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> >> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> >> hp_wmi_classes[type]);
> >> +
> >> +    for (i = 0; i < 3; i++) {
> >> +            status = get_string_from_buffer((u16 **)&obj-
> >>> buffer.pointer, &str);
> >> +            if (ACPI_SUCCESS(status)) {
> >> +                    /*
> >> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> >> since
> >> +                     * 'CurrentValue' is reported.
> >> +                     */
> >> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> >> +                            buf_size = snprintf(buf, alloc_size,
> >> +                                                "%s\t\"%s\": \"%s\",\n",
> >> +                                                buf,
> >> +
> >> hp_wmi_elements[type][i], str);
> >> +            }
> >> +            kfree(str);
> >> +            str = NULL;
> >> +
> >> +    }
> >> +
> >> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> >> +            if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
> >> +                    status = get_string_from_buffer((u16 **)&obj-
> >>> buffer.pointer, &str);
> >> +                    if (ACPI_SUCCESS(status)) {
> >> +                            /*
> >> +                             * Report "CurrentValue" as "Value"
> >> +                             */
> >> +                            buf_size = snprintf(buf, alloc_size,
> >> +                                                "%s\t\"Value\": \"%s\",\n",
> >> buf, str);
> >> +                    }
> >> +                    kfree(str);
> >> +                    str = NULL;
> >> +                    continue;
> >> +
> >> +            } else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
> >> +                    /*
> >> +                     * Report list of "SupportEncoding"
> >> +                     *
> >> +                     *      "SupportedEncoding": [
> >> +                     *              "utf-16"
> >> +                     *      ],
> >> +                     *
> >> +                     */
> >> +
> >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> >> +                                        buf, hp_wmi_elements[type][i]);
> >> +                    for (j = 0; j < size; j++) {
> >> +                            status = get_string_from_buffer((u16
> >> **)&obj->buffer.pointer, &str);
> >> +                            if (ACPI_SUCCESS(status)) {
> >> +                                    if (j == size - 1)
> >> +                                            buf_size = snprintf(buf,
> >> alloc_size,
> >> +
> >> "%s\t\t\"%s\"\n", buf, str);
> >> +                                    else
> >> +                                            buf_size = snprintf(buf,
> >> alloc_size,
> >> +
> >> "%s\t\t\"%s\",\n", buf, str);
> >> +                            }
> >> +                            kfree(str);
> >> +                            str = NULL;
> >> +                    }
> >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >> +                    continue;
> >> +            }
> >> +
> >> +            size = 0;
> >> +            status = get_integer_from_buffer((int **)&obj-
> >>> buffer.pointer, &integer);
> >> +            if (ACPI_SUCCESS(status)) {
> >> +                    /*
> >> +                     * Report "PrerequisiteSize" and "Size" values
> >> +                     *      ...
> >> +                     *      "PrerequisiteSize": 1,
> >> +                     *      ...
> >> +                     *      "Size": 2,
> >> +                     *      ...
> >> +                     */
> >> +                    if (i == 7)
> >> +                            size = integer;
> >> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> >> == 10)
> >> +                            size = integer;
> >> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> >> 9)
> >> +                            size = integer;
> >> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> >> 11)
> >> +                            size = integer;
> >> +
> >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> >> %d,\n", buf,
> >> +                                        hp_wmi_elements[type][i],
> >> integer);
> >> +            }
> >> +
> >> +            if (size > 20)
> >> +                    pr_warn("%s exceeded the maximum number of
> >> elements supported or data may be malformed\n",
> >> +                            hp_wmi_elements[type][i]);
> >> +
> >> +            if (ACPI_SUCCESS(status) && i == 7) {
> >> +                    buf_size = snprintf(buf, alloc_size,
> >> "%s\t\"Prerequisites\": [\n", buf);
> >> +                    for (j = 0; j < size; j++) {
> >> +                            status = get_string_from_buffer((u16
> >> **)&obj->buffer.pointer, &str);
> >> +                            if (ACPI_SUCCESS(status)) {
> >> +                                    buf_size = snprintf(buf, alloc_size,
> >> "%s\t\t\"%s\"", buf, str);
> >> +
> >> +                                    if (j == size - 1)
> >> +                                            buf_size = snprintf(buf,
> >> alloc_size, "%s\n", buf);
> >> +                                    else
> >> +                                            buf_size = snprintf(buf,
> >> alloc_size, "%s,\n", buf);
> >> +
> >> +                            }
> >> +                            kfree(str);
> >> +                            str = NULL;
> >> +                    }
> >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >> +            }
> >> +    }
> >> +
> >> +    if (type == HPWMI_ENUMERATION_TYPE || type ==
> >> HPWMI_ORDEREDLIST_TYPE) {
> >> +            if (type == HPWMI_ENUMERATION_TYPE)
> >> +                    buf_size = snprintf(buf, alloc_size,
> >> "%s\t\"PossibleValues\": [\n", buf);
> >> +            else
> >> +                    buf_size = snprintf(buf, alloc_size,
> >> "%s\t\"Elements\": [\n", buf);
> >> +
> >> +            for (i = 0; i < size; i++) {
> >> +                    status = get_string_from_buffer((u16 **)&obj-
> >>> buffer.pointer, &str);
> >> +                    if (ACPI_SUCCESS(status)) {
> >> +                            buf_size = snprintf(buf, alloc_size,
> >> "%s\t\t\"%s\"", buf, str);
> >> +
> >> +                            if (i == size - 1)
> >> +                                    buf_size = snprintf(buf, alloc_size,
> >> "%s\n", buf);
> >> +                            else
> >> +                                    buf_size = snprintf(buf, alloc_size,
> >> "%s,\n", buf);
> >> +
> >> +                    }
> >> +                    kfree(str);
> >> +                    str = NULL;
> >> +            }
> >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >> +    }
> >> +
> >> +    /*
> >> +     * remove trailing comma
> >> +     */
> >> +    if (buf_size > 3)
> >> +            buf[buf_size - 2] = ' ';
> >> +
> >> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> >> +}
> >> +
> >> +static int hp_bios_settings_free_buffer(void)
> >> +{
> >> +    mutex_lock(&buf_mutex);
> >> +    kfree(hp_bios_settings_buffer);
> >> +    settings_buffer_size = 0;
> >> +    buf_alloc_size = 0;
> >> +    mutex_unlock(&buf_mutex);
> >> +
> >> +    return 0;
> >> +}
> >> +
> >> +static int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
> >> +                                       int *alloc_size,
> >> +                                       struct mutex *buf_mutex)
> >> +{
> >> +    int new_buffer_size;
> >> +    char *new_buf = NULL;
> >> +    int ret = 0;
> >> +
> >> +    if (*buf_size + PAGE_SIZE >= *alloc_size) {
> >> +            new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
> >> +
> >> +            mutex_lock(buf_mutex);
> >> +            new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
> >> +            mutex_unlock(buf_mutex);
> >> +            if (new_buf) {
> >> +                    mutex_lock(buf_mutex);
> >> +                    *buf = new_buf;
> >> +                    *alloc_size = ksize(new_buf);
> >> +                    mutex_unlock(buf_mutex);
> >> +            } else {
> >> +                    hp_bios_settings_free_buffer();
> >> +                    ret = -ENOMEM;
> >> +            }
> >> +    }
> >> +
> >> +    return ret;
> >> +}
> >> +
> >> +static int append_settings_to_buffer(char *guid, int type, char **buf,
> >> +                                 int *buf_size, int *alloc_size,
> >> +                                 struct mutex *buf_mutex)
> >> +{
> >> +    union acpi_object *obj = NULL;
> >> +    int ret = 0;
> >> +    int status = 0;
> >> +    int instance = 0;
> >> +
> >> +    /*
> >> +     * Query all the instances until to receive a AE_BAD_PARAMETER
> >> +     */
> >> +    do {
> >> +            ret = hp_wmi_get_setting_object(guid, instance++, &obj);
> >> +            if (ACPI_SUCCESS(ret) && obj != NULL) {
> >> +                    status = 0;
> >> +                    if (obj->type == ACPI_TYPE_PACKAGE) {
> >> +                            mutex_lock(buf_mutex);
> >> +                            status =
> >> append_package_elements_to_buffer(obj,
> >> +                                                    *buf, *alloc_size,
> >> type);
> >> +                            if (status > 0)
> >> +                                    *buf_size = status;
> >> +                            mutex_unlock(buf_mutex);
> >> +
> >> +                    } else if (obj->type == ACPI_TYPE_BUFFER) {
> >> +                            mutex_lock(buf_mutex);
> >> +                            status =
> >> append_buffer_elements_to_buffer(obj,
> >> +                                                    *buf, *alloc_size,
> >> type);
> >> +                            if (status > 0)
> >> +                                    *buf_size = status;
> >> +                            mutex_unlock(buf_mutex);
> >> +
> >> +                    } else
> >> +                            pr_warn("The retrieved object type(%d) is
> >> not supported yet\n",
> >> +                                    obj->type);
> >> +
> >> +                    ret = hp_bios_settings_realloc_buffer(buf, buf_size,
> >> alloc_size, buf_mutex);
> >> +            }
> >> +
> >> +            kfree(obj);
> >> +            obj = NULL;
> >> +
> >> +    } while (ACPI_SUCCESS(ret));
> >> +
> >> +    /*
> >> +     * AE_BAD_PARAMETER means the loop ended by exhaustion
> >> +     */
> >> +    if (ret == AE_BAD_PARAMETER)
> >> +            ret = 0;
> >> +
> >> +    return ret;
> >> +}
> >> +
> >> +static int hp_bios_settings_fill_buffer(void)
> >> +{
> >> +    int status = 0;
> >> +    int initial_buffer_size = 20 * PAGE_SIZE;
> >> +
> >> +    mutex_lock(&buf_mutex);
> >> +    hp_bios_settings_buffer = kmalloc(initial_buffer_size, GFP_KERNEL);
> >> +    mutex_unlock(&buf_mutex);
> >> +    if (!hp_bios_settings_buffer)
> >> +            return -ENOMEM;
> >> +
> >> +    mutex_lock(&buf_mutex);
> >> +    buf_alloc_size = ksize(hp_bios_settings_buffer);
> >> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> >> +                                    buf_alloc_size, "[\n");
> >> +    mutex_unlock(&buf_mutex);
> >> +
> >> +    status = append_settings_to_buffer(HPWMI_STRING_GUID,
> >> +            HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
> >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >> +    if (ACPI_FAILURE(status))
> >> +            pr_err("error 0x%x occurred retrieving string instances\n",
> >> status);
> >> +
> >> +    status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
> >> +            HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
> >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >> +    if (ACPI_FAILURE(status))
> >> +            pr_err("error 0x%x occurred retrieving integer instances\n",
> >> status);
> >> +
> >> +    status = append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
> >> +            HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
> >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >> +    if (ACPI_FAILURE(status))
> >> +            pr_err("error 0x%x occurred retrieving enumeration
> >> instances\n", status);
> >> +
> >> +    status = append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
> >> +            HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
> >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >> +    if (ACPI_FAILURE(status))
> >> +            pr_err("error 0x%x occurred retrieving ordered list
> >> instances\n", status);
> >> +
> >> +    status = append_settings_to_buffer(HPWMI_PASSWORD_GUID,
> >> +            HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
> >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >> +    if (ACPI_FAILURE(status))
> >> +            pr_err("error 0x%x occurred retrieving password list
> >> instances\n", status);
> >> +
> >> +    mutex_lock(&buf_mutex);
> >> +    /*
> >> +     * remove trailing comma
> >> +     */
> >> +    if (settings_buffer_size >= 3) {
> >> +            if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
> >> +                    hp_bios_settings_buffer[settings_buffer_size - 2] = '
> >> ';
> >> +    }
> >> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> >> +                                    buf_alloc_size, "%s]\n",
> >> +                                    hp_bios_settings_buffer);
> >> +    mutex_unlock(&buf_mutex);
> >> +
> >> +    return settings_buffer_size;
> >> +}
> >> +
> >> +/*
> >> + * sure_admin_settings_read - Return a formatted file with settings
> >> + *                              and possible options read from BIOS
> >> + *
> >> + * @filp:  Pointer to file of settings read from BIOS
> >> + * @kobj:  Pointer to a kernel object of things that show up as directory in
> >> the sysfs filesystem.
> >> + * @attr:  Pointer to list of read attributes
> >> + * @buf:   Pointer to buffer
> >> + * @off:   File current offset
> >> + * @count: Buffer size
> >> + *
> >> + * Returns the count of unicode chars read if successful, otherwise
> >> + *          -ENOMEM unable to allocate memory
> >> + *          -EINVAL buffer not allocated or too small
> >> + *
> >> + */
> >> +static ssize_t sure_admin_settings_read(struct file *filp, struct kobject
> >> *kobj,
> >> +                                    struct bin_attribute *attr, char *buf,
> >> loff_t off, size_t count)
> >> +{
> >> +    ssize_t ret;
> >> +
> >> +    /* clear the buffer when offset is pointing to the last position */
> >> +    if (off >= settings_buffer_size && settings_buffer_size > 0) {
> >> +            hp_bios_settings_free_buffer();
> >> +            return 0;
> >> +    }
> >> +
> >> +    /* clear the buffer whenever the read starts from the first position
> >> */
> >> +    if (off == 0 && settings_buffer_size > 0)
> >> +            hp_bios_settings_free_buffer();
> >> +
> >> +    if (settings_buffer_size == 0)
> >> +            hp_bios_settings_fill_buffer();
> >> +
> >> +    mutex_lock(&buf_mutex);
> >> +    ret = memory_read_from_buffer(buf, count, &off,
> >> hp_bios_settings_buffer,
> >> +                                  settings_buffer_size);
> >> +    mutex_unlock(&buf_mutex);
> >> +
> >> +    return ret;
> >> +}
> >> +
> >> +
> >> +/*
> >> + * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
> >> + *
> >> + * @p:   Unicode buffer address
> >> + * @str: string to convert to unicode
> >> + *
> >> + * Returns a void pointer to the buffer containing unicode string
> >> + */
> >> +static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
> >> +{
> >> +    int len = strlen(str);
> >> +
> >> +    /*
> >> +     * Add null character when reading an empty string
> >> +     */
> >> +    if (len == 0) {
> >> +            *p++ = 2;
> >> +            *p++ = (u8)0x00;
> >> +            return p;
> >> +    }
> >> +    *p++ = len * 2;
> >> +    utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
> >> +    p += len;
> >> +
> >> +    return p;
> >> +}
> >> +
> >> +/*
> >> + * hp_wmi_set_bios_setting - Set setting's value in BIOS
> >> + *
> >> + * @input_buffer: Input buffer address
> >> + * @input_size:   Input buffer size
> >> + *
> >> + * Returns: Count of unicode characters written to BIOS if successful,
> >> otherwise
> >> + *          -ENOMEM unable to allocate memory
> >> + *          -EINVAL buffer not allocated or too small
> >> + */
> >> +static int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
> >> +{
> >> +    union acpi_object *obj;
> >> +    struct acpi_buffer input = {input_size, input_buffer};
> >> +    struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
> >> +    int ret = 0;
> >> +
> >> +    ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID, 0, 1,
> >> &input, &output);
> >> +
> >> +    obj = output.pointer;
> >> +    if (!obj)
> >> +            return -EINVAL;
> >> +
> >> +    if (obj->type != ACPI_TYPE_INTEGER)
> >> +            ret = -EINVAL;
> >> +
> >> +    ret = obj->integer.value;
> >> +    kfree(obj);
> >> +    return ret;
> >> +}
> >> +
> >> +/* Sure Admin Functions */
> >> +
> >> +#define UTF_PREFIX                  ((unsigned char *)"<utf-16/>")
> >> +#define BEAM_PREFIX                 ((unsigned char
> >> *)"<BEAM/>")
> >> +
> >> +/*
> >> + * sure_admin_settings_write - Write the contents of a formatted file
> >> + *                               with settings and performs the logic
> >> + *                               to change any settings in BIOS.
> >> + *
> >> + * @filp:  Pointer to file of settings to be written to BIOS
> >> + * @kobj:  Pointer to a kernel object of things that show up as directory in
> >> the sysfs filesystem.
> >> + * @attr:  Pointer to list of attributes for the write operation
> >> + * @buf:   Pointer to buffer
> >> + * @off:   File current offset
> >> + * @count: Buffer size
> >> + *
> >> + *
> >> + * Returns the count of unicode characters written to BIOS if successful,
> >> otherwise
> >> + *          -ENOMEM unable to allocate memory
> >> + *          -EINVAL buffer not allocated or too small
> >> + *
> >> + */
> >> +static ssize_t sure_admin_settings_write(struct file *filp, struct kobject
> >> *kobj,
> >> +                    struct bin_attribute *attr, char *buf, loff_t off, size_t
> >> count)
> >> +{
> >> +    int status = 0;
> >> +    char *part = NULL;
> >> +    int part_len = 0;
> >> +    unsigned short *buffer = NULL;
> >> +    unsigned short *tmpstr = NULL;
> >> +    int buffer_size = (count + strlen(UTF_PREFIX)) * sizeof(unsigned
> >> short);
> >> +
> >> +    buffer = kmalloc(buffer_size, GFP_KERNEL);
> >> +    if (!buffer)
> >> +            return -ENOMEM;
> >> +
> >> +    tmpstr = buffer;
> >> +    part = strsep(&buf, ",");
> >> +    if (!part) {
> >> +            status = -EINVAL;
> >> +            goto out_free;
> >> +    }
> >> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> >> +    part = strsep(&buf, ",");
> >> +    if (!part) {
> >> +            status = -EINVAL;
> >> +            goto out_free;
> >> +    }
> >> +
> >> +    /* Add extra buffer space when encountering an empty string */
> >> +    if (!strlen(part))
> >> +            buffer_size += sizeof(unsigned short);
> >> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> >> +    part = strsep(&buf, ",");
> >> +    if (!part) {
> >> +            status = -EINVAL;
> >> +            goto out_free;
> >> +    }
> >> +    part_len = strlen(part) - 1;
> >> +    part[part_len] = '\0';
> >> +
> >> +    if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
> >> +           /*
> >> +            * BEAM_PREFIX is append to buffer when a signature
> >> +            * is provided and Sure Admin is enabled in BIOS
> >> +            */
> >> +            // BEAM_PREFIX found, convert part to unicode
> >> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> >> +            // decrease buffer size allocated initially for UTF_PREFIX
> >> +            buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
> >> +    } else {
> >> +            /*
> >> +             * UTF-16 prefix is append to the * buffer when a BIOS
> >> +             * admin password is configured in BIOS
> >> +             */
> >> +
> >> +            // append UTF_PREFIX to part and then convert it to unicode
> >> +            part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
> >> +            if (!part)
> >> +                    goto out_free;
> >> +
> >> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> >> +            kfree(part);
> >> +    }
> >> +
> >> +    part = strsep(&buf, ",");
> >> +    if (part) {
> >> +            status = -EINVAL;
> >> +            goto out_free;
> >> +    }
> >> +    status = hp_wmi_set_bios_setting(buffer, buffer_size);
> >> +    if (ACPI_FAILURE(status))
> >> +            status = -EINVAL;
> >> +
> >> +out_free:
> >> +    kfree(buffer);
> >> +    if (ACPI_SUCCESS(status))
> >> +            return count;
> >> +    return status;
> >> +}
> >> +
> >> +HPWMI_BINATTR_RW(sure_admin, settings, 0);
> >> +
> >> +static struct bin_attribute *sure_admin_binattrs[] = {
> >> +    &sure_admin_settings,
> >> +    NULL,
> >> +};
> >> +
> >> +static const struct attribute_group sure_admin_group = {
> >> +    .name = "sure_admin",
> >> +    .bin_attrs = sure_admin_binattrs,
> >> +};
> >> +
> >>  static DEVICE_ATTR_RO(display);
> >>  static DEVICE_ATTR_RO(hddtemp);
> >>  static DEVICE_ATTR_RW(als);
> >> @@ -1050,6 +2026,7 @@ static const struct attribute_group
> >> *hp_wmi_groups[] = {
> >>      &hp_wmi_group,
> >>      &spm_group,
> >>      &sure_start_group,
> >> +    &sure_admin_group,
> >>      NULL,
> >>  };
> >>
> >> --
> >> 2.25.1
>

Mario Limonciello April 5, 2022, 5:13 p.m. UTC | #4

[Public]



> -----Original Message-----
> From: Jorge Lopez <[e-mail]>
> Sent: Tuesday, April 5, 2022 11:52
> To: Hans de Goede <[e-mail]>
> Cc: Limonciello, Mario <[e-mail]>; platform-driver-
> [e-mail]
> Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
> 
> Hi Hans,
> 
> On Tue, Apr 5, 2022 at 6:54 AM Hans de Goede <[e-mail]>
> wrote:
> >
> > Hi,
> >
> > On 4/4/22 23:59, Limonciello, Mario wrote:
> > > [Public]
> > >
> > >
> > >
> > >> -----Original Message-----
> > >> From: Jorge Lopez <[e-mail]>
> > >> Sent: Monday, April 4, 2022 15:36
> > >> To: [e-mail]
> > >> Subject: [PATCH v1 5/6] Sure Admin Security Feature
> > >>
> > >> HP Commercial PC's have several BIOS settings that control its
> > >> behaviour and capabilities, many of which are related to security.  To
> > >> prevent unauthorized changes to these settings, the system can be
> > >> configured to use a Sure Admin cryptographic signature-based
> > >> authorization string that the BIOS will use to verify authorization to
> > >> modify the setting. Behind the scenes, Sure Admin uses Secure
> Platform
> > >> Management (SPM) and WMI
> > >>
> > >> 'settings' is a file associated with Sure Admin. BIOS settings can be
> > >> read or written through the Sure Admin settings file in sysfs
> > >>
> > >>      /sys/devices/platform/hp-wmi/sure_admin/settings
> > >>
> > >> Expected data format to update BIOS setting
> > >>
> > >>      [BIOS setting],[new value],[auth token]
> > >>
> > >> Sample settings reported data
> > >>
> > >>      {
> > >>              "Class": "HPBIOS_BIOSEnumeration",
> > >>              "Name": "USB Storage Boot",
> > >>              "Path": "\\Advanced\\Boot Options",
> > >>              "IsReadOnly": 0,
> > >>              ...
> > >>              "Value": "Enable",
> > >>              "Size": 2,
> > >>              "PossibleValues": [
> > >>                      "Disable",
> > >>                      "Enable"
> > >>              ]
> > >>      }
> > >>
> > >
> > > This sounds like it has re-invented /sys/class/firmware-attributes.
> > >
> > > Shouldn't you adopt that API?
> >
> > I fully agree. Jorge as I already indicated in our off-list
> > conversation when you initially started working on this
> > feature, we already have a standardized API for querying/changing
> > BIOS settings from within Linux:
> >
> 
> I agree that changing the BIOS settings from within Linux could
> utilize the new methodology,  I will need to look closely at the
> requirements before I can proceed to make the changes.
> Keep in mind authentication of the values is done by BIOS.  No Linux
> process validates any data name, value, or auth token; only BIOS.  All
> data written to the sysfs file is not validated, it is just forward to
> BIOS.  See spm_kek_store and spm_sk_store functions.

That's fine, and it's a safer design to have BIOS validate it.

> One point I must make clear when updating BIOS settings.  any  NOT
> read-only BIOS settings can be changed by the application at any time.
>    This list of settings changes from one system to another.

Right.

> 
> I am in disagreement with reading the settings.  hp-wmi does not read
> one value at a time. It reads all values exposed by BIOS.  See
> attached sample output.

The settings can all be read at initialization time for the driver and cached
then.

> The method for how all BIOS settings are reported needs to match the
> method how Windows products do it.  It is a requirement to start
> migrating customers from Windows to Linux while minimizing how BIOS
> data is reported.

Because we have a standardized API in Linux for this, I think it's best to abstract
this behind a userspace application/script.  If they expect to see it in the format you
showed, the userspace application can take the data from Linux and package it that
way.

You'll have richer libraries and languages and tools to work from when doing this too.
It should make it a lot less painful.

> 
> I will investigate the new API and bring it to the team's attention.
> 
> >
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
> f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
> 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
> &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
> D&amp;reserved=0
> >
> > and any new code (such as this patch) which implements BIOS
> > setting changing MUST follow this standardized API (extending
> > it where necessary).
> >
> > I'm sorry but this patch is not acceptable in its current form,
> > it needs to be *completely rewritten* to implement:
> >
> >
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
> f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
> 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
> &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
> D&amp;reserved=0
> >
> > See:
> >
> >
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fdell%2Fdell-wmi-
> sysman&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8f
> ea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> 7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> mp;sdata=z5jmH7ECYBeLcndQ2vfHaUuyE04Eaf1Lymh6BjnyJ%2Fk%3D&amp;r
> eserved=0
> >
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fthink-
> lmi.c&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea
> 104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C
> 0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLj
> AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;
> sdata=5n6w9LEB2iWpj1cOQP6Ngz94AqP1Bu4vu8T0EdN%2FThU%3D&amp;re
> served=0
> >
> > for example code / for 2 drivers from other vendors already
> > implementing this.
> >
> > The same applies to the:
> >
> > "[PATCH v1 3/6] Secure Platform Management Security Feature"
> >
> > this needs to be implemented as
> > a /sys/class/firmware-attributes/*/authentication/
> > authentication method, see for example these Lenovo specific
> > addition to the /sys/class/firmware-attributes/*/authentication/
> > userspace API for similar functionality on Lenovo Think* devices:
> >
> >
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> 2Fcommit%2F%3Fid%3D06384573a3e8335ac6797577e545c33dbf91b490&amp;
> data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea1040342827
> 08da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C63784
> 7743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLC
> JQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=eldS
> 4H3Z%2BAyL%2FG%2FO9W9rDGC37yh5sGgtUhpKdUAoSmA%3D&amp;reser
> ved=0
> >
> > I'll merge patches 1-2 sometime this week since those are
> > fine and it will be good to have those "out of the way",
> > but the rest of the series will need to be rewritten
> > taken the above comments into account.
> 
> v1-0003-Sure-Start-Security-Feature.patch  reports the number of audit
> logs available and reports them when read.    it does not read/write
> BIOS settings hence it does not fall within the same category as
> patches v1-0002-Secure-Platform-Management-Security-Feature.patch and
> v1-0004-Sure-Admin-Security-Feature.patch
> Do you agree?
> 
> >
> > Regards,
> >
> > Hans
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > >
> > >> This feature requires "Update hp_wmi_group to simplify feature
> > >> addition" patch.
> > >>
> > >> All changes were validated on a HP ZBook Workstation,
> > >> HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
> > >>
> > >> Signed-off-by: Jorge Lopez <[e-mail]>
> > >>
> > >> ---
> > >> Based on the latest platform-drivers-x86.git/for-next
> > >> ---
> > >>  drivers/platform/x86/hp-wmi.c | 977
> > >> ++++++++++++++++++++++++++++++++++
> > >>  1 file changed, 977 insertions(+)
> > >>
> > >> diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-
> wmi.c
> > >> index 918e3eaf1b67..b72ca18b77a6 100644
> > >> --- a/drivers/platform/x86/hp-wmi.c
> > >> +++ b/drivers/platform/x86/hp-wmi.c
> > >> @@ -27,6 +27,7 @@
> > >>  #include <linux/rfkill.h>
> > >>  #include <linux/string.h>
> > >>  #include <linux/dmi.h>
> > >> +#include <linux/nls.h>
> > >>
> > >>  MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
> > >>  MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
> > >> @@ -37,8 +38,16 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-
> > >> 3D44E2C707E4");
> > >>
> > >>  #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-
> ACCDC67EF61C"
> > >>  #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-
> 3D44E2C707E4"
> > >> +
> > >>  #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
> > >>
> > >> +#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-
> 6A1B8106F83C"
> > >> +#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-
> > >> E293ADB9BF05"
> > >> +#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-
> > >> 4A3C09E75133"
> > >> +#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-A0E0-
> > >> 7045CB4DA745"
> > >> +#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-
> > >> 015176049E2D"
> > >> +#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-951D-
> > >> C7CB9B4B8D5E"
> > >> +
> > >>  /* DMI board names of devices that should use the omen specific path
> for
> > >>   * thermal profiles.
> > >>   * This was obtained by taking a look in the windows omen command
> center
> > >> @@ -1025,6 +1034,973 @@ static const struct attribute_group
> > >> sure_start_group = {
> > >>      .attrs = sure_start_attrs,
> > >>  };
> > >>
> > >> +
> > >> +static int convert_hexstr_to_str(char **hex, int input_len, char **str,
> int
> > >> *len)
> > >> +{
> > >> +    int ret = 0;
> > >> +    int new_len = 0;
> > >> +    char tmp[] = "0x00";
> > >> +    char *input = *hex;
> > >> +    char *new_str = NULL;
> > >> +    int  ch;
> > >> +    int i;
> > >> +
> > >> +    if (input_len <= 0 || hex == NULL || str == NULL || len == NULL)
> > >> +            return -EINVAL;
> > >> +
> > >> +    *len = 0;
> > >> +    *str = NULL;
> > >> +
> > >> +    new_str = kmalloc(input_len, GFP_KERNEL);
> > >> +    if (!new_str)
> > >> +            return -ENOMEM;
> > >> +
> > >> +    for (i = 0; i < input_len; i += 5) {
> > >> +            strncpy(tmp, input + i, strlen(tmp));
> > >> +            ret = kstrtoint(tmp, 16, &ch);
> > >> +            if (ret) {
> > >> +                    new_len = 0;
> > >> +                    break;
> > >> +            }
> > >> +
> > >> +            if (ch == '\\')
> > >> +                    new_str[new_len++] = '\\';
> > >> +
> > >> +            new_str[new_len++] = ch;
> > >> +            if (ch == '\0')
> > >> +                    break;
> > >> +    }
> > >> +
> > >> +    if (new_len) {
> > >> +            new_str[new_len] = '\0';
> > >> +            *str = krealloc(new_str, (new_len + 1) * sizeof(char),
> > >> GFP_KERNEL);
> > >> +            if (*str)
> > >> +                    *len = new_len;
> > >> +            else
> > >> +                    ret = -ENOMEM;
> > >> +    }
> > >> +
> > >> +    if (ret)
> > >> +            kfree(new_str);
> > >> +    return ret;
> > >> +}
> > >> +
> > >> +/*
> > >> + * hp_wmi_get_setting_object() - Get an ACPI object by GUID and
> instance
> > >> + *
> > >> + * @guid:   GUID associated with the ACPI list of managed objects
> > >> + * @instance:       Instance index to query on the ACPI list
> > >> + * @obj:    The output ACPI object of type ACPI_TYPE_PACKAGE
> > >> + *          or ACPI_TYPE_BUFFER (freed by the callee)
> > >> + *
> > >> + * Returns  zero on success.  Otherwise,an error inherited from
> > >> + *          wmi_query_block(). It returns a obj by parameter if
> > >> + *          the query returned object of type buffer or package,
> > >> + *          otherwise, a null obj is returned.
> > >> + *
> > >> + * Note: obj should be freed by the callee once it is finished working
> with it
> > >> + */
> > >> +static int hp_wmi_get_setting_object(char *guid, int instance,
> > >> +                            union acpi_object **obj)
> > >> +{
> > >> +    struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER, NULL
> > >> };
> > >> +    union acpi_object *tmp = NULL;
> > >> +    int ret;
> > >> +
> > >> +    ret = wmi_query_block(guid, instance, &output);
> > >> +    if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
> > >> +            tmp = output.pointer;
> > >> +            if (tmp->type == ACPI_TYPE_BUFFER || tmp->type ==
> > >> ACPI_TYPE_PACKAGE)
> > >> +                    *obj = output.pointer;
> > >> +            else {
> > >> +                    kfree(tmp);
> > >> +                    *obj = NULL;
> > >> +            }
> > >> +    }
> > >> +
> > >> +    return ret;
> > >> +}
> > >> +
> > >> +
> > >> +static int get_string_from_buffer(u16 **buffer, char **str)
> > >> +{
> > >> +    u16 *ptr = *buffer;
> > >> +    u16 ptrlen;
> > >> +
> > >> +    u16 size;
> > >> +    int i;
> > >> +    char *output = NULL;
> > >> +    int escape = 0;
> > >> +
> > >> +    ptrlen = *(ptr++);
> > >> +    size = ptrlen / 2;
> > >> +
> > >> +    if (size == 0)
> > >> +            goto cleanup_exit;
> > >> +
> > >> +    for (i = 0; i < size; i++)
> > >> +            if (ptr[i] == '\\')
> > >> +                    escape++;
> > >> +
> > >> +    size += escape;
> > >> +    *str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
> > >> +    if (!*str)
> > >> +            return -ENOMEM;
> > >> +
> > >> +    output = *str;
> > >> +
> > >> +    /*
> > >> +     * convert from UTF-16 unicode to ASCII
> > >> +     */
> > >> +    utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output, size);
> > >> +
> > >> +    if (escape == 0) {
> > >> +            ptr += (ptrlen / 2);
> > >> +            goto cleanup_exit;
> > >> +    }
> > >> +    /*
> > >> +     * Convert escape characters only when found
> > >> +     */
> > >> +    for (i = 0; i < size; i++) {
> > >> +            if (*ptr == '\\')
> > >> +                    output[i++] = '\\';
> > >> +            output[i] = *ptr;
> > >> +            ptr++;
> > >> +    }
> > >> +
> > >> +cleanup_exit:
> > >> +    *buffer = ptr;
> > >> +    return 0;
> > >> +}
> > >> +
> > >> +static int get_integer_from_buffer(int **buffer, int *integer)
> > >> +{
> > >> +    int *ptr = PTR_ALIGN(*buffer, 4);
> > >> +    *integer = *(ptr++);
> > >> +    *buffer = ptr;
> > >> +    return 0;
> > >> +}
> > >> +
> > >> +
> > >> +// Sure Admin functions
> > >> +enum hp_wmi_data_type {
> > >> +    HPWMI_STRING_TYPE,
> > >> +    HPWMI_INTEGER_TYPE,
> > >> +    HPWMI_ENUMERATION_TYPE,
> > >> +    HPWMI_ORDEREDLIST_TYPE,
> > >> +    HPWMI_PASSWORD_TYPE,
> > >> +};
> > >> +
> > >> +#define HP_WMI_COMMON_ELEMENTS      \
> > >> +    "Name", \
> > >> +    "Value",        \
> > >> +    "Path", \
> > >> +    "IsReadOnly",   \
> > >> +    "DisplayInUI",  \
> > >> +    "RequiresPhysicalPresence",     \
> > >> +    "Sequence",     \
> > >> +    "PrerequisiteSize",     \
> > >> +    "SecurityLevel"
> > >> +
> > >> +const char *hp_wmi_string_elements[] = {
> > >> +    HP_WMI_COMMON_ELEMENTS,
> > >> +    "MinLength",
> > >> +    "MaxLength"
> > >> +};
> > >> +
> > >> +const char *hp_wmi_integer_elements[] = {
> > >> +    HP_WMI_COMMON_ELEMENTS,
> > >> +    "LowerBound",
> > >> +    "UpperBound",
> > >> +    "IntValue"
> > >> +};
> > >> +
> > >> +const char *hp_wmi_enumeration_elements[] = {
> > >> +    HP_WMI_COMMON_ELEMENTS,
> > >> +    "CurrentValue",
> > >> +    "Size"
> > >> +};
> > >> +
> > >> +const char *hp_wmi_orderedlist_elements[] = {
> > >> +    HP_WMI_COMMON_ELEMENTS,
> > >> +    "Size"
> > >> +};
> > >> +
> > >> +const char *hp_wmi_password_elements[] = {
> > >> +    HP_WMI_COMMON_ELEMENTS,
> > >> +    "MinLength",
> > >> +    "MaxLength",
> > >> +    "Size",
> > >> +    "SupportedEncoding",
> > >> +    "IsSet"
> > >> +};
> > >> +
> > >> +const char **hp_wmi_elements[] = {
> > >> +    hp_wmi_string_elements,
> > >> +    hp_wmi_integer_elements,
> > >> +    hp_wmi_enumeration_elements,
> > >> +    hp_wmi_orderedlist_elements,
> > >> +    hp_wmi_password_elements
> > >> +};
> > >> +
> > >> +const int hp_wmi_elements_count[] = {
> > >> +    ARRAY_SIZE(hp_wmi_string_elements),
> > >> +    ARRAY_SIZE(hp_wmi_integer_elements),
> > >> +    ARRAY_SIZE(hp_wmi_enumeration_elements),
> > >> +    ARRAY_SIZE(hp_wmi_orderedlist_elements),
> > >> +    ARRAY_SIZE(hp_wmi_password_elements)
> > >> +};
> > >> +
> > >> +const char *hp_wmi_classes[] = {
> > >> +    "HPBIOS_BIOSString",
> > >> +    "HPBIOS_BIOSInteger",
> > >> +    "HPBIOS_BIOSEnumeration",
> > >> +    "HPBIOS_BIOSOrderedList",
> > >> +    "HPBIOS_BIOSPassword"
> > >> +};
> > >> +
> > >> +static DEFINE_MUTEX(buf_mutex);
> > >> +static int settings_buffer_size;
> > >> +static int buf_alloc_size;
> > >> +static char *hp_bios_settings_buffer;
> > >> +
> > >> +
> > >> +static int append_package_elements_to_buffer(union acpi_object
> *obj,
> > >> +                                         char *buf, int alloc_size, enum
> > >> hp_wmi_data_type type)
> > >> +{
> > >> +    int i;
> > >> +    union acpi_object *pobj = NULL;
> > >> +    char *value = NULL;
> > >> +    int value_len;
> > >> +    char *tmpstr = NULL;
> > >> +    char *part_tmp = NULL;
> > >> +    int tmp_len = 0;
> > >> +    char *part = NULL;
> > >> +    int status = 0;
> > >> +    int size = 0;
> > >> +    int buf_size;
> > >> +
> > >> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> > >> +            return -EINVAL;
> > >> +
> > >> +    if (obj->type != ACPI_TYPE_PACKAGE)
> > >> +            return -EINVAL;
> > >> +
> > >> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> > >> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> > >> hp_wmi_classes[type]);
> > >> +
> > >> +    for (i = 0; i < 3; i++) {
> > >> +            pobj = &(obj->package.elements[i]);
> > >> +            if (pobj->type == ACPI_TYPE_STRING) {
> > >> +                    status = convert_hexstr_to_str(&pobj-
> > >>> string.pointer,
> > >> +                                                   pobj->string.length,
> > >> &value, &value_len);
> > >> +                    if (ACPI_FAILURE(status))
> > >> +                            continue;
> > >> +                    /*
> > >> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> > >> since
> > >> +                     * 'CurrentValue' is reported.
> > >> +                     */
> > >> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> > >> +                            buf_size = snprintf(buf, alloc_size,
> > >> +                                                "%s\t\"%s\": \"%s\",\n",
> > >> +                                                buf,
> > >> +
> > >> hp_wmi_elements[type][i], value);
> > >> +
> > >> +            }
> > >> +            kfree(value);
> > >> +            value = NULL;
> > >> +    }
> > >> +
> > >> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> > >> +            pobj = &(obj->package.elements[i]);
> > >> +
> > >> +            if (type == HPWMI_ENUMERATION_TYPE &&
> > >> +                i == 9 &&
> > >> +                pobj->type == ACPI_TYPE_STRING) {
> > >> +                    /*
> > >> +                     * Report "CurrentValue" as "Value"
> > >> +                     */
> > >> +                    status = convert_hexstr_to_str(&pobj-
> > >>> string.pointer,
> > >> +                                                   pobj->string.length,
> > >> +                                                   &value, &value_len);
> > >> +                    if (ACPI_FAILURE(status))
> > >> +                            continue;
> > >> +
> > >> +                    buf_size = snprintf(buf, alloc_size,
> > >> +                                        "%s\t\"Value\": \"%s\",\n",
> > >> +                                        buf, value);
> > >> +                    kfree(value);
> > >> +                    value = NULL;
> > >> +
> > >> +            } else if (type == HPWMI_PASSWORD_TYPE &&
> > >> +                       i == 12 &&
> > >> +                       pobj->type == ACPI_TYPE_STRING) {
> > >> +                    /*
> > >> +                     * Report list of "SupportEncoding"
> > >> +                     *
> > >> +                     *      "SupportedEncoding": [
> > >> +                     *              "utf-16"
> > >> +                     *      ],
> > >> +                     *
> > >> +                     */
> > >> +
> > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> > >> +                                        buf, hp_wmi_elements[type][i]);
> > >> +                    while (size--) {
> > >> +                            pobj = &(obj->package.elements[i]);
> > >> +                            status = convert_hexstr_to_str(&pobj-
> > >>> string.pointer,
> > >> +                                                           pobj-
> > >>> string.length,
> > >> +                                                           &value,
> > >> &value_len);
> > >> +                            if (ACPI_FAILURE(status))
> > >> +                                    continue;
> > >> +
> > >> +                            if (size) {
> > >> +                                    buf_size = snprintf(buf, alloc_size,
> > >> +                                                        "%s\t\t\"%s\",\n",
> > >> buf, value);
> > >> +                                    i++;
> > >> +                            } else
> > >> +                                    buf_size = snprintf(buf, alloc_size,
> > >> +                                                        "%s\t\t\"%s\"\n",
> > >> buf, value);
> > >> +
> > >> +                            kfree(value);
> > >> +                            value = NULL;
> > >> +
> > >> +                    }
> > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >> +                    continue;
> > >> +
> > >> +            } else if (pobj->type == ACPI_TYPE_INTEGER) {
> > >> +                    /*
> > >> +                     * Report "PrerequisiteSize" and "Size" values
> > >> +                     *      ...
> > >> +                     *      "PrerequisiteSize": 1,
> > >> +                     *      ...
> > >> +                     *      "Size": 2,
> > >> +                     *      ...
> > >> +                     */
> > >> +                    if (i == 7)
> > >> +                            size = pobj->integer.value;
> > >> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> > >> 9)
> > >> +                            size = pobj->integer.value;
> > >> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> > >> == 10)
> > >> +                            size = pobj->integer.value;
> > >> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> > >> 11)
> > >> +                            size = pobj->integer.value;
> > >> +
> > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> > >> %lld,\n", buf,
> > >> +                                        hp_wmi_elements[type][i], pobj-
> > >>> integer.value);
> > >> +            }
> > >> +    }
> > >> +
> > >> +    if (type == HPWMI_ENUMERATION_TYPE) {
> > >> +            buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\":
> > >> [\n", buf);
> > >> +            for (i = 0; i < size; i++) {
> > >> +                    pobj = &(obj->package.elements[i +
> > >> hp_wmi_elements_count[type]]);
> > >> +
> > >> +                    status = convert_hexstr_to_str(&pobj-
> > >>> string.pointer,
> > >> +                                                   pobj->string.length,
> > >> +                                                   &value, &value_len);
> > >> +                    if (ACPI_FAILURE(status))
> > >> +                            break;
> > >> +
> > >> +                    /*
> > >> +                     * Report list of "PossibleValues" of size
> > >> +                     * "Size"
> > >> +                     *      ...
> > >> +                     *      "Size": 2,
> > >> +                     *      "PossibleValues": [
> > >> +                     *                      "Disable",
> > >> +                     *                      "Enable"]
> > >> +                     */
> > >> +                    if (i == (size - 1))
> > >> +                            buf_size = snprintf(buf, alloc_size,
> > >> +                                                "%s\t\t\"%s\"\n", buf,
> > >> value);
> > >> +                    else
> > >> +                            buf_size = snprintf(buf, alloc_size,
> > >> +                                                "%s\t\t\"%s\",\n", buf,
> > >> value);
> > >> +                    kfree(value);
> > >> +                    value = NULL;
> > >> +            }
> > >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >> +    }
> > >> +
> > >> +    if (type == HPWMI_ORDEREDLIST_TYPE) {
> > >> +            buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n",
> > >> buf);
> > >> +            if (size <= 0)
> > >> +                    goto finish_ordered_list;
> > >> +
> > >> +            pobj = &(obj-
> > >>> package.elements[hp_wmi_elements_count[type]]);
> > >> +            status = convert_hexstr_to_str(&pobj->string.pointer,
> > >> +                                           pobj->string.length, &value,
> > >> &value_len);
> > >> +            if (ACPI_FAILURE(status))
> > >> +                    goto finish_ordered_list;
> > >> +
> > >> +            /*
> > >> +             * Ordered list data is stored in hex and comma separated
> > >> format
> > >> +             * Convert the data and split it to show each element
> > >> +             */
> > >> +            status = convert_hexstr_to_str(&value, value_len, &tmpstr,
> > >> &tmp_len);
> > >> +            if (ACPI_FAILURE(status))
> > >> +                    goto finish_ordered_list;
> > >> +
> > >> +            part_tmp = tmpstr;
> > >> +            part = strsep(&part_tmp, ",");
> > >> +            while (part) {
> > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"",
> > >> buf, part);
> > >> +                    part = strsep(&part_tmp, ",");
> > >> +                    if (part)
> > >> +                            buf_size = snprintf(buf, alloc_size, "%s,\n",
> > >> buf);
> > >> +                    else
> > >> +                            buf_size = snprintf(buf, alloc_size, "%s\n",
> > >> buf);
> > >> +            }
> > >> +    }
> > >> +
> > >> +finish_ordered_list:
> > >> +    if (type == HPWMI_ORDEREDLIST_TYPE)
> > >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >> +
> > >> +    /*
> > >> +     * remove trailing comma
> > >> +     */
> > >> +    if (buf_size > 3)
> > >> +            buf[buf_size - 2] = ' ';
> > >> +
> > >> +    kfree(tmpstr);
> > >> +    kfree(value);
> > >> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> > >> +}
> > >> +
> > >> +static int append_buffer_elements_to_buffer(union acpi_object *obj,
> > >> +                                        char *buf, int alloc_size, enum
> > >> hp_wmi_data_type type)
> > >> +{
> > >> +    int buf_size;
> > >> +    int status;
> > >> +    char *str = NULL;
> > >> +    int i;
> > >> +    int j;
> > >> +    int integer;
> > >> +    int size = 0;
> > >> +
> > >> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> > >> +            return -EINVAL;
> > >> +
> > >> +    if (obj->type != ACPI_TYPE_BUFFER)
> > >> +            return -EINVAL;
> > >> +
> > >> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> > >> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> > >> hp_wmi_classes[type]);
> > >> +
> > >> +    for (i = 0; i < 3; i++) {
> > >> +            status = get_string_from_buffer((u16 **)&obj-
> > >>> buffer.pointer, &str);
> > >> +            if (ACPI_SUCCESS(status)) {
> > >> +                    /*
> > >> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> > >> since
> > >> +                     * 'CurrentValue' is reported.
> > >> +                     */
> > >> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> > >> +                            buf_size = snprintf(buf, alloc_size,
> > >> +                                                "%s\t\"%s\": \"%s\",\n",
> > >> +                                                buf,
> > >> +
> > >> hp_wmi_elements[type][i], str);
> > >> +            }
> > >> +            kfree(str);
> > >> +            str = NULL;
> > >> +
> > >> +    }
> > >> +
> > >> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> > >> +            if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
> > >> +                    status = get_string_from_buffer((u16 **)&obj-
> > >>> buffer.pointer, &str);
> > >> +                    if (ACPI_SUCCESS(status)) {
> > >> +                            /*
> > >> +                             * Report "CurrentValue" as "Value"
> > >> +                             */
> > >> +                            buf_size = snprintf(buf, alloc_size,
> > >> +                                                "%s\t\"Value\": \"%s\",\n",
> > >> buf, str);
> > >> +                    }
> > >> +                    kfree(str);
> > >> +                    str = NULL;
> > >> +                    continue;
> > >> +
> > >> +            } else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
> > >> +                    /*
> > >> +                     * Report list of "SupportEncoding"
> > >> +                     *
> > >> +                     *      "SupportedEncoding": [
> > >> +                     *              "utf-16"
> > >> +                     *      ],
> > >> +                     *
> > >> +                     */
> > >> +
> > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> > >> +                                        buf, hp_wmi_elements[type][i]);
> > >> +                    for (j = 0; j < size; j++) {
> > >> +                            status = get_string_from_buffer((u16
> > >> **)&obj->buffer.pointer, &str);
> > >> +                            if (ACPI_SUCCESS(status)) {
> > >> +                                    if (j == size - 1)
> > >> +                                            buf_size = snprintf(buf,
> > >> alloc_size,
> > >> +
> > >> "%s\t\t\"%s\"\n", buf, str);
> > >> +                                    else
> > >> +                                            buf_size = snprintf(buf,
> > >> alloc_size,
> > >> +
> > >> "%s\t\t\"%s\",\n", buf, str);
> > >> +                            }
> > >> +                            kfree(str);
> > >> +                            str = NULL;
> > >> +                    }
> > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >> +                    continue;
> > >> +            }
> > >> +
> > >> +            size = 0;
> > >> +            status = get_integer_from_buffer((int **)&obj-
> > >>> buffer.pointer, &integer);
> > >> +            if (ACPI_SUCCESS(status)) {
> > >> +                    /*
> > >> +                     * Report "PrerequisiteSize" and "Size" values
> > >> +                     *      ...
> > >> +                     *      "PrerequisiteSize": 1,
> > >> +                     *      ...
> > >> +                     *      "Size": 2,
> > >> +                     *      ...
> > >> +                     */
> > >> +                    if (i == 7)
> > >> +                            size = integer;
> > >> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> > >> == 10)
> > >> +                            size = integer;
> > >> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> > >> 9)
> > >> +                            size = integer;
> > >> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> > >> 11)
> > >> +                            size = integer;
> > >> +
> > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> > >> %d,\n", buf,
> > >> +                                        hp_wmi_elements[type][i],
> > >> integer);
> > >> +            }
> > >> +
> > >> +            if (size > 20)
> > >> +                    pr_warn("%s exceeded the maximum number of
> > >> elements supported or data may be malformed\n",
> > >> +                            hp_wmi_elements[type][i]);
> > >> +
> > >> +            if (ACPI_SUCCESS(status) && i == 7) {
> > >> +                    buf_size = snprintf(buf, alloc_size,
> > >> "%s\t\"Prerequisites\": [\n", buf);
> > >> +                    for (j = 0; j < size; j++) {
> > >> +                            status = get_string_from_buffer((u16
> > >> **)&obj->buffer.pointer, &str);
> > >> +                            if (ACPI_SUCCESS(status)) {
> > >> +                                    buf_size = snprintf(buf, alloc_size,
> > >> "%s\t\t\"%s\"", buf, str);
> > >> +
> > >> +                                    if (j == size - 1)
> > >> +                                            buf_size = snprintf(buf,
> > >> alloc_size, "%s\n", buf);
> > >> +                                    else
> > >> +                                            buf_size = snprintf(buf,
> > >> alloc_size, "%s,\n", buf);
> > >> +
> > >> +                            }
> > >> +                            kfree(str);
> > >> +                            str = NULL;
> > >> +                    }
> > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >> +            }
> > >> +    }
> > >> +
> > >> +    if (type == HPWMI_ENUMERATION_TYPE || type ==
> > >> HPWMI_ORDEREDLIST_TYPE) {
> > >> +            if (type == HPWMI_ENUMERATION_TYPE)
> > >> +                    buf_size = snprintf(buf, alloc_size,
> > >> "%s\t\"PossibleValues\": [\n", buf);
> > >> +            else
> > >> +                    buf_size = snprintf(buf, alloc_size,
> > >> "%s\t\"Elements\": [\n", buf);
> > >> +
> > >> +            for (i = 0; i < size; i++) {
> > >> +                    status = get_string_from_buffer((u16 **)&obj-
> > >>> buffer.pointer, &str);
> > >> +                    if (ACPI_SUCCESS(status)) {
> > >> +                            buf_size = snprintf(buf, alloc_size,
> > >> "%s\t\t\"%s\"", buf, str);
> > >> +
> > >> +                            if (i == size - 1)
> > >> +                                    buf_size = snprintf(buf, alloc_size,
> > >> "%s\n", buf);
> > >> +                            else
> > >> +                                    buf_size = snprintf(buf, alloc_size,
> > >> "%s,\n", buf);
> > >> +
> > >> +                    }
> > >> +                    kfree(str);
> > >> +                    str = NULL;
> > >> +            }
> > >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >> +    }
> > >> +
> > >> +    /*
> > >> +     * remove trailing comma
> > >> +     */
> > >> +    if (buf_size > 3)
> > >> +            buf[buf_size - 2] = ' ';
> > >> +
> > >> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> > >> +}
> > >> +
> > >> +static int hp_bios_settings_free_buffer(void)
> > >> +{
> > >> +    mutex_lock(&buf_mutex);
> > >> +    kfree(hp_bios_settings_buffer);
> > >> +    settings_buffer_size = 0;
> > >> +    buf_alloc_size = 0;
> > >> +    mutex_unlock(&buf_mutex);
> > >> +
> > >> +    return 0;
> > >> +}
> > >> +
> > >> +static int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
> > >> +                                       int *alloc_size,
> > >> +                                       struct mutex *buf_mutex)
> > >> +{
> > >> +    int new_buffer_size;
> > >> +    char *new_buf = NULL;
> > >> +    int ret = 0;
> > >> +
> > >> +    if (*buf_size + PAGE_SIZE >= *alloc_size) {
> > >> +            new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
> > >> +
> > >> +            mutex_lock(buf_mutex);
> > >> +            new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
> > >> +            mutex_unlock(buf_mutex);
> > >> +            if (new_buf) {
> > >> +                    mutex_lock(buf_mutex);
> > >> +                    *buf = new_buf;
> > >> +                    *alloc_size = ksize(new_buf);
> > >> +                    mutex_unlock(buf_mutex);
> > >> +            } else {
> > >> +                    hp_bios_settings_free_buffer();
> > >> +                    ret = -ENOMEM;
> > >> +            }
> > >> +    }
> > >> +
> > >> +    return ret;
> > >> +}
> > >> +
> > >> +static int append_settings_to_buffer(char *guid, int type, char **buf,
> > >> +                                 int *buf_size, int *alloc_size,
> > >> +                                 struct mutex *buf_mutex)
> > >> +{
> > >> +    union acpi_object *obj = NULL;
> > >> +    int ret = 0;
> > >> +    int status = 0;
> > >> +    int instance = 0;
> > >> +
> > >> +    /*
> > >> +     * Query all the instances until to receive a AE_BAD_PARAMETER
> > >> +     */
> > >> +    do {
> > >> +            ret = hp_wmi_get_setting_object(guid, instance++, &obj);
> > >> +            if (ACPI_SUCCESS(ret) && obj != NULL) {
> > >> +                    status = 0;
> > >> +                    if (obj->type == ACPI_TYPE_PACKAGE) {
> > >> +                            mutex_lock(buf_mutex);
> > >> +                            status =
> > >> append_package_elements_to_buffer(obj,
> > >> +                                                    *buf, *alloc_size,
> > >> type);
> > >> +                            if (status > 0)
> > >> +                                    *buf_size = status;
> > >> +                            mutex_unlock(buf_mutex);
> > >> +
> > >> +                    } else if (obj->type == ACPI_TYPE_BUFFER) {
> > >> +                            mutex_lock(buf_mutex);
> > >> +                            status =
> > >> append_buffer_elements_to_buffer(obj,
> > >> +                                                    *buf, *alloc_size,
> > >> type);
> > >> +                            if (status > 0)
> > >> +                                    *buf_size = status;
> > >> +                            mutex_unlock(buf_mutex);
> > >> +
> > >> +                    } else
> > >> +                            pr_warn("The retrieved object type(%d) is
> > >> not supported yet\n",
> > >> +                                    obj->type);
> > >> +
> > >> +                    ret = hp_bios_settings_realloc_buffer(buf, buf_size,
> > >> alloc_size, buf_mutex);
> > >> +            }
> > >> +
> > >> +            kfree(obj);
> > >> +            obj = NULL;
> > >> +
> > >> +    } while (ACPI_SUCCESS(ret));
> > >> +
> > >> +    /*
> > >> +     * AE_BAD_PARAMETER means the loop ended by exhaustion
> > >> +     */
> > >> +    if (ret == AE_BAD_PARAMETER)
> > >> +            ret = 0;
> > >> +
> > >> +    return ret;
> > >> +}
> > >> +
> > >> +static int hp_bios_settings_fill_buffer(void)
> > >> +{
> > >> +    int status = 0;
> > >> +    int initial_buffer_size = 20 * PAGE_SIZE;
> > >> +
> > >> +    mutex_lock(&buf_mutex);
> > >> +    hp_bios_settings_buffer = kmalloc(initial_buffer_size,
> GFP_KERNEL);
> > >> +    mutex_unlock(&buf_mutex);
> > >> +    if (!hp_bios_settings_buffer)
> > >> +            return -ENOMEM;
> > >> +
> > >> +    mutex_lock(&buf_mutex);
> > >> +    buf_alloc_size = ksize(hp_bios_settings_buffer);
> > >> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> > >> +                                    buf_alloc_size, "[\n");
> > >> +    mutex_unlock(&buf_mutex);
> > >> +
> > >> +    status = append_settings_to_buffer(HPWMI_STRING_GUID,
> > >> +            HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
> > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >> +    if (ACPI_FAILURE(status))
> > >> +            pr_err("error 0x%x occurred retrieving string instances\n",
> > >> status);
> > >> +
> > >> +    status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
> > >> +            HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
> > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >> +    if (ACPI_FAILURE(status))
> > >> +            pr_err("error 0x%x occurred retrieving integer instances\n",
> > >> status);
> > >> +
> > >> +    status =
> append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
> > >> +            HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
> > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >> +    if (ACPI_FAILURE(status))
> > >> +            pr_err("error 0x%x occurred retrieving enumeration
> > >> instances\n", status);
> > >> +
> > >> +    status = append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
> > >> +            HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
> > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >> +    if (ACPI_FAILURE(status))
> > >> +            pr_err("error 0x%x occurred retrieving ordered list
> > >> instances\n", status);
> > >> +
> > >> +    status = append_settings_to_buffer(HPWMI_PASSWORD_GUID,
> > >> +            HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
> > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >> +    if (ACPI_FAILURE(status))
> > >> +            pr_err("error 0x%x occurred retrieving password list
> > >> instances\n", status);
> > >> +
> > >> +    mutex_lock(&buf_mutex);
> > >> +    /*
> > >> +     * remove trailing comma
> > >> +     */
> > >> +    if (settings_buffer_size >= 3) {
> > >> +            if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
> > >> +                    hp_bios_settings_buffer[settings_buffer_size - 2] = '
> > >> ';
> > >> +    }
> > >> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> > >> +                                    buf_alloc_size, "%s]\n",
> > >> +                                    hp_bios_settings_buffer);
> > >> +    mutex_unlock(&buf_mutex);
> > >> +
> > >> +    return settings_buffer_size;
> > >> +}
> > >> +
> > >> +/*
> > >> + * sure_admin_settings_read - Return a formatted file with settings
> > >> + *                              and possible options read from BIOS
> > >> + *
> > >> + * @filp:  Pointer to file of settings read from BIOS
> > >> + * @kobj:  Pointer to a kernel object of things that show up as directory
> in
> > >> the sysfs filesystem.
> > >> + * @attr:  Pointer to list of read attributes
> > >> + * @buf:   Pointer to buffer
> > >> + * @off:   File current offset
> > >> + * @count: Buffer size
> > >> + *
> > >> + * Returns the count of unicode chars read if successful, otherwise
> > >> + *          -ENOMEM unable to allocate memory
> > >> + *          -EINVAL buffer not allocated or too small
> > >> + *
> > >> + */
> > >> +static ssize_t sure_admin_settings_read(struct file *filp, struct kobject
> > >> *kobj,
> > >> +                                    struct bin_attribute *attr, char *buf,
> > >> loff_t off, size_t count)
> > >> +{
> > >> +    ssize_t ret;
> > >> +
> > >> +    /* clear the buffer when offset is pointing to the last position */
> > >> +    if (off >= settings_buffer_size && settings_buffer_size > 0) {
> > >> +            hp_bios_settings_free_buffer();
> > >> +            return 0;
> > >> +    }
> > >> +
> > >> +    /* clear the buffer whenever the read starts from the first position
> > >> */
> > >> +    if (off == 0 && settings_buffer_size > 0)
> > >> +            hp_bios_settings_free_buffer();
> > >> +
> > >> +    if (settings_buffer_size == 0)
> > >> +            hp_bios_settings_fill_buffer();
> > >> +
> > >> +    mutex_lock(&buf_mutex);
> > >> +    ret = memory_read_from_buffer(buf, count, &off,
> > >> hp_bios_settings_buffer,
> > >> +                                  settings_buffer_size);
> > >> +    mutex_unlock(&buf_mutex);
> > >> +
> > >> +    return ret;
> > >> +}
> > >> +
> > >> +
> > >> +/*
> > >> + * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
> > >> + *
> > >> + * @p:   Unicode buffer address
> > >> + * @str: string to convert to unicode
> > >> + *
> > >> + * Returns a void pointer to the buffer containing unicode string
> > >> + */
> > >> +static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
> > >> +{
> > >> +    int len = strlen(str);
> > >> +
> > >> +    /*
> > >> +     * Add null character when reading an empty string
> > >> +     */
> > >> +    if (len == 0) {
> > >> +            *p++ = 2;
> > >> +            *p++ = (u8)0x00;
> > >> +            return p;
> > >> +    }
> > >> +    *p++ = len * 2;
> > >> +    utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
> > >> +    p += len;
> > >> +
> > >> +    return p;
> > >> +}
> > >> +
> > >> +/*
> > >> + * hp_wmi_set_bios_setting - Set setting's value in BIOS
> > >> + *
> > >> + * @input_buffer: Input buffer address
> > >> + * @input_size:   Input buffer size
> > >> + *
> > >> + * Returns: Count of unicode characters written to BIOS if successful,
> > >> otherwise
> > >> + *          -ENOMEM unable to allocate memory
> > >> + *          -EINVAL buffer not allocated or too small
> > >> + */
> > >> +static int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
> > >> +{
> > >> +    union acpi_object *obj;
> > >> +    struct acpi_buffer input = {input_size, input_buffer};
> > >> +    struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
> > >> +    int ret = 0;
> > >> +
> > >> +    ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID, 0, 1,
> > >> &input, &output);
> > >> +
> > >> +    obj = output.pointer;
> > >> +    if (!obj)
> > >> +            return -EINVAL;
> > >> +
> > >> +    if (obj->type != ACPI_TYPE_INTEGER)
> > >> +            ret = -EINVAL;
> > >> +
> > >> +    ret = obj->integer.value;
> > >> +    kfree(obj);
> > >> +    return ret;
> > >> +}
> > >> +
> > >> +/* Sure Admin Functions */
> > >> +
> > >> +#define UTF_PREFIX                  ((unsigned char *)"<utf-16/>")
> > >> +#define BEAM_PREFIX                 ((unsigned char
> > >> *)"<BEAM/>")
> > >> +
> > >> +/*
> > >> + * sure_admin_settings_write - Write the contents of a formatted file
> > >> + *                               with settings and performs the logic
> > >> + *                               to change any settings in BIOS.
> > >> + *
> > >> + * @filp:  Pointer to file of settings to be written to BIOS
> > >> + * @kobj:  Pointer to a kernel object of things that show up as directory
> in
> > >> the sysfs filesystem.
> > >> + * @attr:  Pointer to list of attributes for the write operation
> > >> + * @buf:   Pointer to buffer
> > >> + * @off:   File current offset
> > >> + * @count: Buffer size
> > >> + *
> > >> + *
> > >> + * Returns the count of unicode characters written to BIOS if
> successful,
> > >> otherwise
> > >> + *          -ENOMEM unable to allocate memory
> > >> + *          -EINVAL buffer not allocated or too small
> > >> + *
> > >> + */
> > >> +static ssize_t sure_admin_settings_write(struct file *filp, struct kobject
> > >> *kobj,
> > >> +                    struct bin_attribute *attr, char *buf, loff_t off, size_t
> > >> count)
> > >> +{
> > >> +    int status = 0;
> > >> +    char *part = NULL;
> > >> +    int part_len = 0;
> > >> +    unsigned short *buffer = NULL;
> > >> +    unsigned short *tmpstr = NULL;
> > >> +    int buffer_size = (count + strlen(UTF_PREFIX)) * sizeof(unsigned
> > >> short);
> > >> +
> > >> +    buffer = kmalloc(buffer_size, GFP_KERNEL);
> > >> +    if (!buffer)
> > >> +            return -ENOMEM;
> > >> +
> > >> +    tmpstr = buffer;
> > >> +    part = strsep(&buf, ",");
> > >> +    if (!part) {
> > >> +            status = -EINVAL;
> > >> +            goto out_free;
> > >> +    }
> > >> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > >> +    part = strsep(&buf, ",");
> > >> +    if (!part) {
> > >> +            status = -EINVAL;
> > >> +            goto out_free;
> > >> +    }
> > >> +
> > >> +    /* Add extra buffer space when encountering an empty string */
> > >> +    if (!strlen(part))
> > >> +            buffer_size += sizeof(unsigned short);
> > >> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > >> +    part = strsep(&buf, ",");
> > >> +    if (!part) {
> > >> +            status = -EINVAL;
> > >> +            goto out_free;
> > >> +    }
> > >> +    part_len = strlen(part) - 1;
> > >> +    part[part_len] = '\0';
> > >> +
> > >> +    if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
> > >> +           /*
> > >> +            * BEAM_PREFIX is append to buffer when a signature
> > >> +            * is provided and Sure Admin is enabled in BIOS
> > >> +            */
> > >> +            // BEAM_PREFIX found, convert part to unicode
> > >> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > >> +            // decrease buffer size allocated initially for UTF_PREFIX
> > >> +            buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
> > >> +    } else {
> > >> +            /*
> > >> +             * UTF-16 prefix is append to the * buffer when a BIOS
> > >> +             * admin password is configured in BIOS
> > >> +             */
> > >> +
> > >> +            // append UTF_PREFIX to part and then convert it to unicode
> > >> +            part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
> > >> +            if (!part)
> > >> +                    goto out_free;
> > >> +
> > >> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > >> +            kfree(part);
> > >> +    }
> > >> +
> > >> +    part = strsep(&buf, ",");
> > >> +    if (part) {
> > >> +            status = -EINVAL;
> > >> +            goto out_free;
> > >> +    }
> > >> +    status = hp_wmi_set_bios_setting(buffer, buffer_size);
> > >> +    if (ACPI_FAILURE(status))
> > >> +            status = -EINVAL;
> > >> +
> > >> +out_free:
> > >> +    kfree(buffer);
> > >> +    if (ACPI_SUCCESS(status))
> > >> +            return count;
> > >> +    return status;
> > >> +}
> > >> +
> > >> +HPWMI_BINATTR_RW(sure_admin, settings, 0);
> > >> +
> > >> +static struct bin_attribute *sure_admin_binattrs[] = {
> > >> +    &sure_admin_settings,
> > >> +    NULL,
> > >> +};
> > >> +
> > >> +static const struct attribute_group sure_admin_group = {
> > >> +    .name = "sure_admin",
> > >> +    .bin_attrs = sure_admin_binattrs,
> > >> +};
> > >> +
> > >>  static DEVICE_ATTR_RO(display);
> > >>  static DEVICE_ATTR_RO(hddtemp);
> > >>  static DEVICE_ATTR_RW(als);
> > >> @@ -1050,6 +2026,7 @@ static const struct attribute_group
> > >> *hp_wmi_groups[] = {
> > >>      &hp_wmi_group,
> > >>      &spm_group,
> > >>      &sure_start_group,
> > >> +    &sure_admin_group,
> > >>      NULL,
> > >>  };
> > >>
> > >> --
> > >> 2.25.1
> >

Jorge Lopez April 7, 2022, 1:44 p.m. UTC | #5

Hans, Mario,

The code links make references to code that implements the new
interfaces but there’s
still code in the kernel that uses the old ones.  I do agree we should
be forward looking
and want to be good participants in the kernel development, but can’t
let our immediate
business needs be impacted with opportunities to enhance the driver to
take advantage
of the latest kernel features.

Rewriting those security features will impact customer business
datelines requiring
HP to provide private releases as the kernel version changes.   The
requested changes
will impact products in the market and HP ability to help customers to
migrate to Linux
from Windows products.

It is because of the immediate business needs, avoiding impacting our
customers/products,
and rewriting  enhancements to the driver that I need to propose an
interim solution.

My proposal is to introduce a read/write value accessible in the user
space to control how
the driver reports and handles BIOS settings and values.  The new
configuration features
will be gradually disabled  as they are converted to use the standardized API.
It is like the configuration flag used to overcome the tablet detection problem
introduced in the past.   The changes solely affect the HP WMI driver.
This option will help us
move forward for this release and give us time to make the necessary
changes to both
the driver and support applications.

Please let me know if this is a viable interim solution.

If it is not possible, I need to ask where the actual written
requirement is found so I can
include them in the business justification for changes and release
delays to management.


Regards,

Jorge Lopez


On Tue, Apr 5, 2022 at 12:13 PM Limonciello, Mario
<[e-mail]> wrote:
>
> [Public]
>
>
>
> > -----Original Message-----
> > From: Jorge Lopez <[e-mail]>
> > Sent: Tuesday, April 5, 2022 11:52
> > To: Hans de Goede <[e-mail]>
> > Cc: Limonciello, Mario <[e-mail]>; platform-driver-
> > [e-mail]
> > Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
> >
> > Hi Hans,
> >
> > On Tue, Apr 5, 2022 at 6:54 AM Hans de Goede <[e-mail]>
> > wrote:
> > >
> > > Hi,
> > >
> > > On 4/4/22 23:59, Limonciello, Mario wrote:
> > > > [Public]
> > > >
> > > >
> > > >
> > > >> -----Original Message-----
> > > >> From: Jorge Lopez <[e-mail]>
> > > >> Sent: Monday, April 4, 2022 15:36
> > > >> To: [e-mail]
> > > >> Subject: [PATCH v1 5/6] Sure Admin Security Feature
> > > >>
> > > >> HP Commercial PC's have several BIOS settings that control its
> > > >> behaviour and capabilities, many of which are related to security.  To
> > > >> prevent unauthorized changes to these settings, the system can be
> > > >> configured to use a Sure Admin cryptographic signature-based
> > > >> authorization string that the BIOS will use to verify authorization to
> > > >> modify the setting. Behind the scenes, Sure Admin uses Secure
> > Platform
> > > >> Management (SPM) and WMI
> > > >>
> > > >> 'settings' is a file associated with Sure Admin. BIOS settings can be
> > > >> read or written through the Sure Admin settings file in sysfs
> > > >>
> > > >>      /sys/devices/platform/hp-wmi/sure_admin/settings
> > > >>
> > > >> Expected data format to update BIOS setting
> > > >>
> > > >>      [BIOS setting],[new value],[auth token]
> > > >>
> > > >> Sample settings reported data
> > > >>
> > > >>      {
> > > >>              "Class": "HPBIOS_BIOSEnumeration",
> > > >>              "Name": "USB Storage Boot",
> > > >>              "Path": "\\Advanced\\Boot Options",
> > > >>              "IsReadOnly": 0,
> > > >>              ...
> > > >>              "Value": "Enable",
> > > >>              "Size": 2,
> > > >>              "PossibleValues": [
> > > >>                      "Disable",
> > > >>                      "Enable"
> > > >>              ]
> > > >>      }
> > > >>
> > > >
> > > > This sounds like it has re-invented /sys/class/firmware-attributes.
> > > >
> > > > Shouldn't you adopt that API?
> > >
> > > I fully agree. Jorge as I already indicated in our off-list
> > > conversation when you initially started working on this
> > > feature, we already have a standardized API for querying/changing
> > > BIOS settings from within Linux:
> > >
> >
> > I agree that changing the BIOS settings from within Linux could
> > utilize the new methodology,  I will need to look closely at the
> > requirements before I can proceed to make the changes.
> > Keep in mind authentication of the values is done by BIOS.  No Linux
> > process validates any data name, value, or auth token; only BIOS.  All
> > data written to the sysfs file is not validated, it is just forward to
> > BIOS.  See spm_kek_store and spm_sk_store functions.
>
> That's fine, and it's a safer design to have BIOS validate it.
>
> > One point I must make clear when updating BIOS settings.  any  NOT
> > read-only BIOS settings can be changed by the application at any time.
> >    This list of settings changes from one system to another.
>
> Right.
>
> >
> > I am in disagreement with reading the settings.  hp-wmi does not read
> > one value at a time. It reads all values exposed by BIOS.  See
> > attached sample output.
>
> The settings can all be read at initialization time for the driver and cached
> then.
>
> > The method for how all BIOS settings are reported needs to match the
> > method how Windows products do it.  It is a requirement to start
> > migrating customers from Windows to Linux while minimizing how BIOS
> > data is reported.
>
> Because we have a standardized API in Linux for this, I think it's best to abstract
> this behind a userspace application/script.  If they expect to see it in the format you
> showed, the userspace application can take the data from Linux and package it that
> way.
>
> You'll have richer libraries and languages and tools to work from when doing this too.
> It should make it a lot less painful.
>
> >
> > I will investigate the new API and bring it to the team's attention.
> >
> > >
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> > ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> > attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
> > f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
> > 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> > C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
> > &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
> > D&amp;reserved=0
> > >
> > > and any new code (such as this patch) which implements BIOS
> > > setting changing MUST follow this standardized API (extending
> > > it where necessary).
> > >
> > > I'm sorry but this patch is not acceptable in its current form,
> > > it needs to be *completely rewritten* to implement:
> > >
> > >
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> > ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> > attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
> > f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
> > 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> > C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
> > &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
> > D&amp;reserved=0
> > >
> > > See:
> > >
> > >
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> > ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fdell%2Fdell-wmi-
> > sysman&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8f
> > ea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> > 7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> > wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> > mp;sdata=z5jmH7ECYBeLcndQ2vfHaUuyE04Eaf1Lymh6BjnyJ%2Fk%3D&amp;r
> > eserved=0
> > >
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> > ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fthink-
> > lmi.c&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea
> > 104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C
> > 0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLj
> > AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;
> > sdata=5n6w9LEB2iWpj1cOQP6Ngz94AqP1Bu4vu8T0EdN%2FThU%3D&amp;re
> > served=0
> > >
> > > for example code / for 2 drivers from other vendors already
> > > implementing this.
> > >
> > > The same applies to the:
> > >
> > > "[PATCH v1 3/6] Secure Platform Management Security Feature"
> > >
> > > this needs to be implemented as
> > > a /sys/class/firmware-attributes/*/authentication/
> > > authentication method, see for example these Lenovo specific
> > > addition to the /sys/class/firmware-attributes/*/authentication/
> > > userspace API for similar functionality on Lenovo Think* devices:
> > >
> > >
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> > ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > 2Fcommit%2F%3Fid%3D06384573a3e8335ac6797577e545c33dbf91b490&amp;
> > data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea1040342827
> > 08da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C63784
> > 7743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLC
> > JQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=eldS
> > 4H3Z%2BAyL%2FG%2FO9W9rDGC37yh5sGgtUhpKdUAoSmA%3D&amp;reser
> > ved=0
> > >
> > > I'll merge patches 1-2 sometime this week since those are
> > > fine and it will be good to have those "out of the way",
> > > but the rest of the series will need to be rewritten
> > > taken the above comments into account.
> >
> > v1-0003-Sure-Start-Security-Feature.patch  reports the number of audit
> > logs available and reports them when read.    it does not read/write
> > BIOS settings hence it does not fall within the same category as
> > patches v1-0002-Secure-Platform-Management-Security-Feature.patch and
> > v1-0004-Sure-Admin-Security-Feature.patch
> > Do you agree?
> >
> > >
> > > Regards,
> > >
> > > Hans
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > >
> > > >> This feature requires "Update hp_wmi_group to simplify feature
> > > >> addition" patch.
> > > >>
> > > >> All changes were validated on a HP ZBook Workstation,
> > > >> HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
> > > >>
> > > >> Signed-off-by: Jorge Lopez <[e-mail]>
> > > >>
> > > >> ---
> > > >> Based on the latest platform-drivers-x86.git/for-next
> > > >> ---
> > > >>  drivers/platform/x86/hp-wmi.c | 977
> > > >> ++++++++++++++++++++++++++++++++++
> > > >>  1 file changed, 977 insertions(+)
> > > >>
> > > >> diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-
> > wmi.c
> > > >> index 918e3eaf1b67..b72ca18b77a6 100644
> > > >> --- a/drivers/platform/x86/hp-wmi.c
> > > >> +++ b/drivers/platform/x86/hp-wmi.c
> > > >> @@ -27,6 +27,7 @@
> > > >>  #include <linux/rfkill.h>
> > > >>  #include <linux/string.h>
> > > >>  #include <linux/dmi.h>
> > > >> +#include <linux/nls.h>
> > > >>
> > > >>  MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
> > > >>  MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
> > > >> @@ -37,8 +38,16 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-
> > > >> 3D44E2C707E4");
> > > >>
> > > >>  #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-
> > ACCDC67EF61C"
> > > >>  #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-
> > 3D44E2C707E4"
> > > >> +
> > > >>  #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
> > > >>
> > > >> +#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-
> > 6A1B8106F83C"
> > > >> +#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-
> > > >> E293ADB9BF05"
> > > >> +#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-
> > > >> 4A3C09E75133"
> > > >> +#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-A0E0-
> > > >> 7045CB4DA745"
> > > >> +#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-
> > > >> 015176049E2D"
> > > >> +#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-951D-
> > > >> C7CB9B4B8D5E"
> > > >> +
> > > >>  /* DMI board names of devices that should use the omen specific path
> > for
> > > >>   * thermal profiles.
> > > >>   * This was obtained by taking a look in the windows omen command
> > center
> > > >> @@ -1025,6 +1034,973 @@ static const struct attribute_group
> > > >> sure_start_group = {
> > > >>      .attrs = sure_start_attrs,
> > > >>  };
> > > >>
> > > >> +
> > > >> +static int convert_hexstr_to_str(char **hex, int input_len, char **str,
> > int
> > > >> *len)
> > > >> +{
> > > >> +    int ret = 0;
> > > >> +    int new_len = 0;
> > > >> +    char tmp[] = "0x00";
> > > >> +    char *input = *hex;
> > > >> +    char *new_str = NULL;
> > > >> +    int  ch;
> > > >> +    int i;
> > > >> +
> > > >> +    if (input_len <= 0 || hex == NULL || str == NULL || len == NULL)
> > > >> +            return -EINVAL;
> > > >> +
> > > >> +    *len = 0;
> > > >> +    *str = NULL;
> > > >> +
> > > >> +    new_str = kmalloc(input_len, GFP_KERNEL);
> > > >> +    if (!new_str)
> > > >> +            return -ENOMEM;
> > > >> +
> > > >> +    for (i = 0; i < input_len; i += 5) {
> > > >> +            strncpy(tmp, input + i, strlen(tmp));
> > > >> +            ret = kstrtoint(tmp, 16, &ch);
> > > >> +            if (ret) {
> > > >> +                    new_len = 0;
> > > >> +                    break;
> > > >> +            }
> > > >> +
> > > >> +            if (ch == '\\')
> > > >> +                    new_str[new_len++] = '\\';
> > > >> +
> > > >> +            new_str[new_len++] = ch;
> > > >> +            if (ch == '\0')
> > > >> +                    break;
> > > >> +    }
> > > >> +
> > > >> +    if (new_len) {
> > > >> +            new_str[new_len] = '\0';
> > > >> +            *str = krealloc(new_str, (new_len + 1) * sizeof(char),
> > > >> GFP_KERNEL);
> > > >> +            if (*str)
> > > >> +                    *len = new_len;
> > > >> +            else
> > > >> +                    ret = -ENOMEM;
> > > >> +    }
> > > >> +
> > > >> +    if (ret)
> > > >> +            kfree(new_str);
> > > >> +    return ret;
> > > >> +}
> > > >> +
> > > >> +/*
> > > >> + * hp_wmi_get_setting_object() - Get an ACPI object by GUID and
> > instance
> > > >> + *
> > > >> + * @guid:   GUID associated with the ACPI list of managed objects
> > > >> + * @instance:       Instance index to query on the ACPI list
> > > >> + * @obj:    The output ACPI object of type ACPI_TYPE_PACKAGE
> > > >> + *          or ACPI_TYPE_BUFFER (freed by the callee)
> > > >> + *
> > > >> + * Returns  zero on success.  Otherwise,an error inherited from
> > > >> + *          wmi_query_block(). It returns a obj by parameter if
> > > >> + *          the query returned object of type buffer or package,
> > > >> + *          otherwise, a null obj is returned.
> > > >> + *
> > > >> + * Note: obj should be freed by the callee once it is finished working
> > with it
> > > >> + */
> > > >> +static int hp_wmi_get_setting_object(char *guid, int instance,
> > > >> +                            union acpi_object **obj)
> > > >> +{
> > > >> +    struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER, NULL
> > > >> };
> > > >> +    union acpi_object *tmp = NULL;
> > > >> +    int ret;
> > > >> +
> > > >> +    ret = wmi_query_block(guid, instance, &output);
> > > >> +    if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
> > > >> +            tmp = output.pointer;
> > > >> +            if (tmp->type == ACPI_TYPE_BUFFER || tmp->type ==
> > > >> ACPI_TYPE_PACKAGE)
> > > >> +                    *obj = output.pointer;
> > > >> +            else {
> > > >> +                    kfree(tmp);
> > > >> +                    *obj = NULL;
> > > >> +            }
> > > >> +    }
> > > >> +
> > > >> +    return ret;
> > > >> +}
> > > >> +
> > > >> +
> > > >> +static int get_string_from_buffer(u16 **buffer, char **str)
> > > >> +{
> > > >> +    u16 *ptr = *buffer;
> > > >> +    u16 ptrlen;
> > > >> +
> > > >> +    u16 size;
> > > >> +    int i;
> > > >> +    char *output = NULL;
> > > >> +    int escape = 0;
> > > >> +
> > > >> +    ptrlen = *(ptr++);
> > > >> +    size = ptrlen / 2;
> > > >> +
> > > >> +    if (size == 0)
> > > >> +            goto cleanup_exit;
> > > >> +
> > > >> +    for (i = 0; i < size; i++)
> > > >> +            if (ptr[i] == '\\')
> > > >> +                    escape++;
> > > >> +
> > > >> +    size += escape;
> > > >> +    *str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
> > > >> +    if (!*str)
> > > >> +            return -ENOMEM;
> > > >> +
> > > >> +    output = *str;
> > > >> +
> > > >> +    /*
> > > >> +     * convert from UTF-16 unicode to ASCII
> > > >> +     */
> > > >> +    utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output, size);
> > > >> +
> > > >> +    if (escape == 0) {
> > > >> +            ptr += (ptrlen / 2);
> > > >> +            goto cleanup_exit;
> > > >> +    }
> > > >> +    /*
> > > >> +     * Convert escape characters only when found
> > > >> +     */
> > > >> +    for (i = 0; i < size; i++) {
> > > >> +            if (*ptr == '\\')
> > > >> +                    output[i++] = '\\';
> > > >> +            output[i] = *ptr;
> > > >> +            ptr++;
> > > >> +    }
> > > >> +
> > > >> +cleanup_exit:
> > > >> +    *buffer = ptr;
> > > >> +    return 0;
> > > >> +}
> > > >> +
> > > >> +static int get_integer_from_buffer(int **buffer, int *integer)
> > > >> +{
> > > >> +    int *ptr = PTR_ALIGN(*buffer, 4);
> > > >> +    *integer = *(ptr++);
> > > >> +    *buffer = ptr;
> > > >> +    return 0;
> > > >> +}
> > > >> +
> > > >> +
> > > >> +// Sure Admin functions
> > > >> +enum hp_wmi_data_type {
> > > >> +    HPWMI_STRING_TYPE,
> > > >> +    HPWMI_INTEGER_TYPE,
> > > >> +    HPWMI_ENUMERATION_TYPE,
> > > >> +    HPWMI_ORDEREDLIST_TYPE,
> > > >> +    HPWMI_PASSWORD_TYPE,
> > > >> +};
> > > >> +
> > > >> +#define HP_WMI_COMMON_ELEMENTS      \
> > > >> +    "Name", \
> > > >> +    "Value",        \
> > > >> +    "Path", \
> > > >> +    "IsReadOnly",   \
> > > >> +    "DisplayInUI",  \
> > > >> +    "RequiresPhysicalPresence",     \
> > > >> +    "Sequence",     \
> > > >> +    "PrerequisiteSize",     \
> > > >> +    "SecurityLevel"
> > > >> +
> > > >> +const char *hp_wmi_string_elements[] = {
> > > >> +    HP_WMI_COMMON_ELEMENTS,
> > > >> +    "MinLength",
> > > >> +    "MaxLength"
> > > >> +};
> > > >> +
> > > >> +const char *hp_wmi_integer_elements[] = {
> > > >> +    HP_WMI_COMMON_ELEMENTS,
> > > >> +    "LowerBound",
> > > >> +    "UpperBound",
> > > >> +    "IntValue"
> > > >> +};
> > > >> +
> > > >> +const char *hp_wmi_enumeration_elements[] = {
> > > >> +    HP_WMI_COMMON_ELEMENTS,
> > > >> +    "CurrentValue",
> > > >> +    "Size"
> > > >> +};
> > > >> +
> > > >> +const char *hp_wmi_orderedlist_elements[] = {
> > > >> +    HP_WMI_COMMON_ELEMENTS,
> > > >> +    "Size"
> > > >> +};
> > > >> +
> > > >> +const char *hp_wmi_password_elements[] = {
> > > >> +    HP_WMI_COMMON_ELEMENTS,
> > > >> +    "MinLength",
> > > >> +    "MaxLength",
> > > >> +    "Size",
> > > >> +    "SupportedEncoding",
> > > >> +    "IsSet"
> > > >> +};
> > > >> +
> > > >> +const char **hp_wmi_elements[] = {
> > > >> +    hp_wmi_string_elements,
> > > >> +    hp_wmi_integer_elements,
> > > >> +    hp_wmi_enumeration_elements,
> > > >> +    hp_wmi_orderedlist_elements,
> > > >> +    hp_wmi_password_elements
> > > >> +};
> > > >> +
> > > >> +const int hp_wmi_elements_count[] = {
> > > >> +    ARRAY_SIZE(hp_wmi_string_elements),
> > > >> +    ARRAY_SIZE(hp_wmi_integer_elements),
> > > >> +    ARRAY_SIZE(hp_wmi_enumeration_elements),
> > > >> +    ARRAY_SIZE(hp_wmi_orderedlist_elements),
> > > >> +    ARRAY_SIZE(hp_wmi_password_elements)
> > > >> +};
> > > >> +
> > > >> +const char *hp_wmi_classes[] = {
> > > >> +    "HPBIOS_BIOSString",
> > > >> +    "HPBIOS_BIOSInteger",
> > > >> +    "HPBIOS_BIOSEnumeration",
> > > >> +    "HPBIOS_BIOSOrderedList",
> > > >> +    "HPBIOS_BIOSPassword"
> > > >> +};
> > > >> +
> > > >> +static DEFINE_MUTEX(buf_mutex);
> > > >> +static int settings_buffer_size;
> > > >> +static int buf_alloc_size;
> > > >> +static char *hp_bios_settings_buffer;
> > > >> +
> > > >> +
> > > >> +static int append_package_elements_to_buffer(union acpi_object
> > *obj,
> > > >> +                                         char *buf, int alloc_size, enum
> > > >> hp_wmi_data_type type)
> > > >> +{
> > > >> +    int i;
> > > >> +    union acpi_object *pobj = NULL;
> > > >> +    char *value = NULL;
> > > >> +    int value_len;
> > > >> +    char *tmpstr = NULL;
> > > >> +    char *part_tmp = NULL;
> > > >> +    int tmp_len = 0;
> > > >> +    char *part = NULL;
> > > >> +    int status = 0;
> > > >> +    int size = 0;
> > > >> +    int buf_size;
> > > >> +
> > > >> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> > > >> +            return -EINVAL;
> > > >> +
> > > >> +    if (obj->type != ACPI_TYPE_PACKAGE)
> > > >> +            return -EINVAL;
> > > >> +
> > > >> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> > > >> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> > > >> hp_wmi_classes[type]);
> > > >> +
> > > >> +    for (i = 0; i < 3; i++) {
> > > >> +            pobj = &(obj->package.elements[i]);
> > > >> +            if (pobj->type == ACPI_TYPE_STRING) {
> > > >> +                    status = convert_hexstr_to_str(&pobj-
> > > >>> string.pointer,
> > > >> +                                                   pobj->string.length,
> > > >> &value, &value_len);
> > > >> +                    if (ACPI_FAILURE(status))
> > > >> +                            continue;
> > > >> +                    /*
> > > >> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> > > >> since
> > > >> +                     * 'CurrentValue' is reported.
> > > >> +                     */
> > > >> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> > > >> +                            buf_size = snprintf(buf, alloc_size,
> > > >> +                                                "%s\t\"%s\": \"%s\",\n",
> > > >> +                                                buf,
> > > >> +
> > > >> hp_wmi_elements[type][i], value);
> > > >> +
> > > >> +            }
> > > >> +            kfree(value);
> > > >> +            value = NULL;
> > > >> +    }
> > > >> +
> > > >> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> > > >> +            pobj = &(obj->package.elements[i]);
> > > >> +
> > > >> +            if (type == HPWMI_ENUMERATION_TYPE &&
> > > >> +                i == 9 &&
> > > >> +                pobj->type == ACPI_TYPE_STRING) {
> > > >> +                    /*
> > > >> +                     * Report "CurrentValue" as "Value"
> > > >> +                     */
> > > >> +                    status = convert_hexstr_to_str(&pobj-
> > > >>> string.pointer,
> > > >> +                                                   pobj->string.length,
> > > >> +                                                   &value, &value_len);
> > > >> +                    if (ACPI_FAILURE(status))
> > > >> +                            continue;
> > > >> +
> > > >> +                    buf_size = snprintf(buf, alloc_size,
> > > >> +                                        "%s\t\"Value\": \"%s\",\n",
> > > >> +                                        buf, value);
> > > >> +                    kfree(value);
> > > >> +                    value = NULL;
> > > >> +
> > > >> +            } else if (type == HPWMI_PASSWORD_TYPE &&
> > > >> +                       i == 12 &&
> > > >> +                       pobj->type == ACPI_TYPE_STRING) {
> > > >> +                    /*
> > > >> +                     * Report list of "SupportEncoding"
> > > >> +                     *
> > > >> +                     *      "SupportedEncoding": [
> > > >> +                     *              "utf-16"
> > > >> +                     *      ],
> > > >> +                     *
> > > >> +                     */
> > > >> +
> > > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> > > >> +                                        buf, hp_wmi_elements[type][i]);
> > > >> +                    while (size--) {
> > > >> +                            pobj = &(obj->package.elements[i]);
> > > >> +                            status = convert_hexstr_to_str(&pobj-
> > > >>> string.pointer,
> > > >> +                                                           pobj-
> > > >>> string.length,
> > > >> +                                                           &value,
> > > >> &value_len);
> > > >> +                            if (ACPI_FAILURE(status))
> > > >> +                                    continue;
> > > >> +
> > > >> +                            if (size) {
> > > >> +                                    buf_size = snprintf(buf, alloc_size,
> > > >> +                                                        "%s\t\t\"%s\",\n",
> > > >> buf, value);
> > > >> +                                    i++;
> > > >> +                            } else
> > > >> +                                    buf_size = snprintf(buf, alloc_size,
> > > >> +                                                        "%s\t\t\"%s\"\n",
> > > >> buf, value);
> > > >> +
> > > >> +                            kfree(value);
> > > >> +                            value = NULL;
> > > >> +
> > > >> +                    }
> > > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > > >> +                    continue;
> > > >> +
> > > >> +            } else if (pobj->type == ACPI_TYPE_INTEGER) {
> > > >> +                    /*
> > > >> +                     * Report "PrerequisiteSize" and "Size" values
> > > >> +                     *      ...
> > > >> +                     *      "PrerequisiteSize": 1,
> > > >> +                     *      ...
> > > >> +                     *      "Size": 2,
> > > >> +                     *      ...
> > > >> +                     */
> > > >> +                    if (i == 7)
> > > >> +                            size = pobj->integer.value;
> > > >> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> > > >> 9)
> > > >> +                            size = pobj->integer.value;
> > > >> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> > > >> == 10)
> > > >> +                            size = pobj->integer.value;
> > > >> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> > > >> 11)
> > > >> +                            size = pobj->integer.value;
> > > >> +
> > > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> > > >> %lld,\n", buf,
> > > >> +                                        hp_wmi_elements[type][i], pobj-
> > > >>> integer.value);
> > > >> +            }
> > > >> +    }
> > > >> +
> > > >> +    if (type == HPWMI_ENUMERATION_TYPE) {
> > > >> +            buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\":
> > > >> [\n", buf);
> > > >> +            for (i = 0; i < size; i++) {
> > > >> +                    pobj = &(obj->package.elements[i +
> > > >> hp_wmi_elements_count[type]]);
> > > >> +
> > > >> +                    status = convert_hexstr_to_str(&pobj-
> > > >>> string.pointer,
> > > >> +                                                   pobj->string.length,
> > > >> +                                                   &value, &value_len);
> > > >> +                    if (ACPI_FAILURE(status))
> > > >> +                            break;
> > > >> +
> > > >> +                    /*
> > > >> +                     * Report list of "PossibleValues" of size
> > > >> +                     * "Size"
> > > >> +                     *      ...
> > > >> +                     *      "Size": 2,
> > > >> +                     *      "PossibleValues": [
> > > >> +                     *                      "Disable",
> > > >> +                     *                      "Enable"]
> > > >> +                     */
> > > >> +                    if (i == (size - 1))
> > > >> +                            buf_size = snprintf(buf, alloc_size,
> > > >> +                                                "%s\t\t\"%s\"\n", buf,
> > > >> value);
> > > >> +                    else
> > > >> +                            buf_size = snprintf(buf, alloc_size,
> > > >> +                                                "%s\t\t\"%s\",\n", buf,
> > > >> value);
> > > >> +                    kfree(value);
> > > >> +                    value = NULL;
> > > >> +            }
> > > >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > > >> +    }
> > > >> +
> > > >> +    if (type == HPWMI_ORDEREDLIST_TYPE) {
> > > >> +            buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n",
> > > >> buf);
> > > >> +            if (size <= 0)
> > > >> +                    goto finish_ordered_list;
> > > >> +
> > > >> +            pobj = &(obj-
> > > >>> package.elements[hp_wmi_elements_count[type]]);
> > > >> +            status = convert_hexstr_to_str(&pobj->string.pointer,
> > > >> +                                           pobj->string.length, &value,
> > > >> &value_len);
> > > >> +            if (ACPI_FAILURE(status))
> > > >> +                    goto finish_ordered_list;
> > > >> +
> > > >> +            /*
> > > >> +             * Ordered list data is stored in hex and comma separated
> > > >> format
> > > >> +             * Convert the data and split it to show each element
> > > >> +             */
> > > >> +            status = convert_hexstr_to_str(&value, value_len, &tmpstr,
> > > >> &tmp_len);
> > > >> +            if (ACPI_FAILURE(status))
> > > >> +                    goto finish_ordered_list;
> > > >> +
> > > >> +            part_tmp = tmpstr;
> > > >> +            part = strsep(&part_tmp, ",");
> > > >> +            while (part) {
> > > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"",
> > > >> buf, part);
> > > >> +                    part = strsep(&part_tmp, ",");
> > > >> +                    if (part)
> > > >> +                            buf_size = snprintf(buf, alloc_size, "%s,\n",
> > > >> buf);
> > > >> +                    else
> > > >> +                            buf_size = snprintf(buf, alloc_size, "%s\n",
> > > >> buf);
> > > >> +            }
> > > >> +    }
> > > >> +
> > > >> +finish_ordered_list:
> > > >> +    if (type == HPWMI_ORDEREDLIST_TYPE)
> > > >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > > >> +
> > > >> +    /*
> > > >> +     * remove trailing comma
> > > >> +     */
> > > >> +    if (buf_size > 3)
> > > >> +            buf[buf_size - 2] = ' ';
> > > >> +
> > > >> +    kfree(tmpstr);
> > > >> +    kfree(value);
> > > >> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> > > >> +}
> > > >> +
> > > >> +static int append_buffer_elements_to_buffer(union acpi_object *obj,
> > > >> +                                        char *buf, int alloc_size, enum
> > > >> hp_wmi_data_type type)
> > > >> +{
> > > >> +    int buf_size;
> > > >> +    int status;
> > > >> +    char *str = NULL;
> > > >> +    int i;
> > > >> +    int j;
> > > >> +    int integer;
> > > >> +    int size = 0;
> > > >> +
> > > >> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> > > >> +            return -EINVAL;
> > > >> +
> > > >> +    if (obj->type != ACPI_TYPE_BUFFER)
> > > >> +            return -EINVAL;
> > > >> +
> > > >> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> > > >> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> > > >> hp_wmi_classes[type]);
> > > >> +
> > > >> +    for (i = 0; i < 3; i++) {
> > > >> +            status = get_string_from_buffer((u16 **)&obj-
> > > >>> buffer.pointer, &str);
> > > >> +            if (ACPI_SUCCESS(status)) {
> > > >> +                    /*
> > > >> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> > > >> since
> > > >> +                     * 'CurrentValue' is reported.
> > > >> +                     */
> > > >> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> > > >> +                            buf_size = snprintf(buf, alloc_size,
> > > >> +                                                "%s\t\"%s\": \"%s\",\n",
> > > >> +                                                buf,
> > > >> +
> > > >> hp_wmi_elements[type][i], str);
> > > >> +            }
> > > >> +            kfree(str);
> > > >> +            str = NULL;
> > > >> +
> > > >> +    }
> > > >> +
> > > >> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> > > >> +            if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
> > > >> +                    status = get_string_from_buffer((u16 **)&obj-
> > > >>> buffer.pointer, &str);
> > > >> +                    if (ACPI_SUCCESS(status)) {
> > > >> +                            /*
> > > >> +                             * Report "CurrentValue" as "Value"
> > > >> +                             */
> > > >> +                            buf_size = snprintf(buf, alloc_size,
> > > >> +                                                "%s\t\"Value\": \"%s\",\n",
> > > >> buf, str);
> > > >> +                    }
> > > >> +                    kfree(str);
> > > >> +                    str = NULL;
> > > >> +                    continue;
> > > >> +
> > > >> +            } else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
> > > >> +                    /*
> > > >> +                     * Report list of "SupportEncoding"
> > > >> +                     *
> > > >> +                     *      "SupportedEncoding": [
> > > >> +                     *              "utf-16"
> > > >> +                     *      ],
> > > >> +                     *
> > > >> +                     */
> > > >> +
> > > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> > > >> +                                        buf, hp_wmi_elements[type][i]);
> > > >> +                    for (j = 0; j < size; j++) {
> > > >> +                            status = get_string_from_buffer((u16
> > > >> **)&obj->buffer.pointer, &str);
> > > >> +                            if (ACPI_SUCCESS(status)) {
> > > >> +                                    if (j == size - 1)
> > > >> +                                            buf_size = snprintf(buf,
> > > >> alloc_size,
> > > >> +
> > > >> "%s\t\t\"%s\"\n", buf, str);
> > > >> +                                    else
> > > >> +                                            buf_size = snprintf(buf,
> > > >> alloc_size,
> > > >> +
> > > >> "%s\t\t\"%s\",\n", buf, str);
> > > >> +                            }
> > > >> +                            kfree(str);
> > > >> +                            str = NULL;
> > > >> +                    }
> > > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > > >> +                    continue;
> > > >> +            }
> > > >> +
> > > >> +            size = 0;
> > > >> +            status = get_integer_from_buffer((int **)&obj-
> > > >>> buffer.pointer, &integer);
> > > >> +            if (ACPI_SUCCESS(status)) {
> > > >> +                    /*
> > > >> +                     * Report "PrerequisiteSize" and "Size" values
> > > >> +                     *      ...
> > > >> +                     *      "PrerequisiteSize": 1,
> > > >> +                     *      ...
> > > >> +                     *      "Size": 2,
> > > >> +                     *      ...
> > > >> +                     */
> > > >> +                    if (i == 7)
> > > >> +                            size = integer;
> > > >> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> > > >> == 10)
> > > >> +                            size = integer;
> > > >> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> > > >> 9)
> > > >> +                            size = integer;
> > > >> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> > > >> 11)
> > > >> +                            size = integer;
> > > >> +
> > > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> > > >> %d,\n", buf,
> > > >> +                                        hp_wmi_elements[type][i],
> > > >> integer);
> > > >> +            }
> > > >> +
> > > >> +            if (size > 20)
> > > >> +                    pr_warn("%s exceeded the maximum number of
> > > >> elements supported or data may be malformed\n",
> > > >> +                            hp_wmi_elements[type][i]);
> > > >> +
> > > >> +            if (ACPI_SUCCESS(status) && i == 7) {
> > > >> +                    buf_size = snprintf(buf, alloc_size,
> > > >> "%s\t\"Prerequisites\": [\n", buf);
> > > >> +                    for (j = 0; j < size; j++) {
> > > >> +                            status = get_string_from_buffer((u16
> > > >> **)&obj->buffer.pointer, &str);
> > > >> +                            if (ACPI_SUCCESS(status)) {
> > > >> +                                    buf_size = snprintf(buf, alloc_size,
> > > >> "%s\t\t\"%s\"", buf, str);
> > > >> +
> > > >> +                                    if (j == size - 1)
> > > >> +                                            buf_size = snprintf(buf,
> > > >> alloc_size, "%s\n", buf);
> > > >> +                                    else
> > > >> +                                            buf_size = snprintf(buf,
> > > >> alloc_size, "%s,\n", buf);
> > > >> +
> > > >> +                            }
> > > >> +                            kfree(str);
> > > >> +                            str = NULL;
> > > >> +                    }
> > > >> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > > >> +            }
> > > >> +    }
> > > >> +
> > > >> +    if (type == HPWMI_ENUMERATION_TYPE || type ==
> > > >> HPWMI_ORDEREDLIST_TYPE) {
> > > >> +            if (type == HPWMI_ENUMERATION_TYPE)
> > > >> +                    buf_size = snprintf(buf, alloc_size,
> > > >> "%s\t\"PossibleValues\": [\n", buf);
> > > >> +            else
> > > >> +                    buf_size = snprintf(buf, alloc_size,
> > > >> "%s\t\"Elements\": [\n", buf);
> > > >> +
> > > >> +            for (i = 0; i < size; i++) {
> > > >> +                    status = get_string_from_buffer((u16 **)&obj-
> > > >>> buffer.pointer, &str);
> > > >> +                    if (ACPI_SUCCESS(status)) {
> > > >> +                            buf_size = snprintf(buf, alloc_size,
> > > >> "%s\t\t\"%s\"", buf, str);
> > > >> +
> > > >> +                            if (i == size - 1)
> > > >> +                                    buf_size = snprintf(buf, alloc_size,
> > > >> "%s\n", buf);
> > > >> +                            else
> > > >> +                                    buf_size = snprintf(buf, alloc_size,
> > > >> "%s,\n", buf);
> > > >> +
> > > >> +                    }
> > > >> +                    kfree(str);
> > > >> +                    str = NULL;
> > > >> +            }
> > > >> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > > >> +    }
> > > >> +
> > > >> +    /*
> > > >> +     * remove trailing comma
> > > >> +     */
> > > >> +    if (buf_size > 3)
> > > >> +            buf[buf_size - 2] = ' ';
> > > >> +
> > > >> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> > > >> +}
> > > >> +
> > > >> +static int hp_bios_settings_free_buffer(void)
> > > >> +{
> > > >> +    mutex_lock(&buf_mutex);
> > > >> +    kfree(hp_bios_settings_buffer);
> > > >> +    settings_buffer_size = 0;
> > > >> +    buf_alloc_size = 0;
> > > >> +    mutex_unlock(&buf_mutex);
> > > >> +
> > > >> +    return 0;
> > > >> +}
> > > >> +
> > > >> +static int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
> > > >> +                                       int *alloc_size,
> > > >> +                                       struct mutex *buf_mutex)
> > > >> +{
> > > >> +    int new_buffer_size;
> > > >> +    char *new_buf = NULL;
> > > >> +    int ret = 0;
> > > >> +
> > > >> +    if (*buf_size + PAGE_SIZE >= *alloc_size) {
> > > >> +            new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
> > > >> +
> > > >> +            mutex_lock(buf_mutex);
> > > >> +            new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
> > > >> +            mutex_unlock(buf_mutex);
> > > >> +            if (new_buf) {
> > > >> +                    mutex_lock(buf_mutex);
> > > >> +                    *buf = new_buf;
> > > >> +                    *alloc_size = ksize(new_buf);
> > > >> +                    mutex_unlock(buf_mutex);
> > > >> +            } else {
> > > >> +                    hp_bios_settings_free_buffer();
> > > >> +                    ret = -ENOMEM;
> > > >> +            }
> > > >> +    }
> > > >> +
> > > >> +    return ret;
> > > >> +}
> > > >> +
> > > >> +static int append_settings_to_buffer(char *guid, int type, char **buf,
> > > >> +                                 int *buf_size, int *alloc_size,
> > > >> +                                 struct mutex *buf_mutex)
> > > >> +{
> > > >> +    union acpi_object *obj = NULL;
> > > >> +    int ret = 0;
> > > >> +    int status = 0;
> > > >> +    int instance = 0;
> > > >> +
> > > >> +    /*
> > > >> +     * Query all the instances until to receive a AE_BAD_PARAMETER
> > > >> +     */
> > > >> +    do {
> > > >> +            ret = hp_wmi_get_setting_object(guid, instance++, &obj);
> > > >> +            if (ACPI_SUCCESS(ret) && obj != NULL) {
> > > >> +                    status = 0;
> > > >> +                    if (obj->type == ACPI_TYPE_PACKAGE) {
> > > >> +                            mutex_lock(buf_mutex);
> > > >> +                            status =
> > > >> append_package_elements_to_buffer(obj,
> > > >> +                                                    *buf, *alloc_size,
> > > >> type);
> > > >> +                            if (status > 0)
> > > >> +                                    *buf_size = status;
> > > >> +                            mutex_unlock(buf_mutex);
> > > >> +
> > > >> +                    } else if (obj->type == ACPI_TYPE_BUFFER) {
> > > >> +                            mutex_lock(buf_mutex);
> > > >> +                            status =
> > > >> append_buffer_elements_to_buffer(obj,
> > > >> +                                                    *buf, *alloc_size,
> > > >> type);
> > > >> +                            if (status > 0)
> > > >> +                                    *buf_size = status;
> > > >> +                            mutex_unlock(buf_mutex);
> > > >> +
> > > >> +                    } else
> > > >> +                            pr_warn("The retrieved object type(%d) is
> > > >> not supported yet\n",
> > > >> +                                    obj->type);
> > > >> +
> > > >> +                    ret = hp_bios_settings_realloc_buffer(buf, buf_size,
> > > >> alloc_size, buf_mutex);
> > > >> +            }
> > > >> +
> > > >> +            kfree(obj);
> > > >> +            obj = NULL;
> > > >> +
> > > >> +    } while (ACPI_SUCCESS(ret));
> > > >> +
> > > >> +    /*
> > > >> +     * AE_BAD_PARAMETER means the loop ended by exhaustion
> > > >> +     */
> > > >> +    if (ret == AE_BAD_PARAMETER)
> > > >> +            ret = 0;
> > > >> +
> > > >> +    return ret;
> > > >> +}
> > > >> +
> > > >> +static int hp_bios_settings_fill_buffer(void)
> > > >> +{
> > > >> +    int status = 0;
> > > >> +    int initial_buffer_size = 20 * PAGE_SIZE;
> > > >> +
> > > >> +    mutex_lock(&buf_mutex);
> > > >> +    hp_bios_settings_buffer = kmalloc(initial_buffer_size,
> > GFP_KERNEL);
> > > >> +    mutex_unlock(&buf_mutex);
> > > >> +    if (!hp_bios_settings_buffer)
> > > >> +            return -ENOMEM;
> > > >> +
> > > >> +    mutex_lock(&buf_mutex);
> > > >> +    buf_alloc_size = ksize(hp_bios_settings_buffer);
> > > >> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> > > >> +                                    buf_alloc_size, "[\n");
> > > >> +    mutex_unlock(&buf_mutex);
> > > >> +
> > > >> +    status = append_settings_to_buffer(HPWMI_STRING_GUID,
> > > >> +            HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
> > > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > > >> +    if (ACPI_FAILURE(status))
> > > >> +            pr_err("error 0x%x occurred retrieving string instances\n",
> > > >> status);
> > > >> +
> > > >> +    status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
> > > >> +            HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
> > > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > > >> +    if (ACPI_FAILURE(status))
> > > >> +            pr_err("error 0x%x occurred retrieving integer instances\n",
> > > >> status);
> > > >> +
> > > >> +    status =
> > append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
> > > >> +            HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
> > > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > > >> +    if (ACPI_FAILURE(status))
> > > >> +            pr_err("error 0x%x occurred retrieving enumeration
> > > >> instances\n", status);
> > > >> +
> > > >> +    status = append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
> > > >> +            HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
> > > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > > >> +    if (ACPI_FAILURE(status))
> > > >> +            pr_err("error 0x%x occurred retrieving ordered list
> > > >> instances\n", status);
> > > >> +
> > > >> +    status = append_settings_to_buffer(HPWMI_PASSWORD_GUID,
> > > >> +            HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
> > > >> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > > >> +    if (ACPI_FAILURE(status))
> > > >> +            pr_err("error 0x%x occurred retrieving password list
> > > >> instances\n", status);
> > > >> +
> > > >> +    mutex_lock(&buf_mutex);
> > > >> +    /*
> > > >> +     * remove trailing comma
> > > >> +     */
> > > >> +    if (settings_buffer_size >= 3) {
> > > >> +            if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
> > > >> +                    hp_bios_settings_buffer[settings_buffer_size - 2] = '
> > > >> ';
> > > >> +    }
> > > >> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> > > >> +                                    buf_alloc_size, "%s]\n",
> > > >> +                                    hp_bios_settings_buffer);
> > > >> +    mutex_unlock(&buf_mutex);
> > > >> +
> > > >> +    return settings_buffer_size;
> > > >> +}
> > > >> +
> > > >> +/*
> > > >> + * sure_admin_settings_read - Return a formatted file with settings
> > > >> + *                              and possible options read from BIOS
> > > >> + *
> > > >> + * @filp:  Pointer to file of settings read from BIOS
> > > >> + * @kobj:  Pointer to a kernel object of things that show up as directory
> > in
> > > >> the sysfs filesystem.
> > > >> + * @attr:  Pointer to list of read attributes
> > > >> + * @buf:   Pointer to buffer
> > > >> + * @off:   File current offset
> > > >> + * @count: Buffer size
> > > >> + *
> > > >> + * Returns the count of unicode chars read if successful, otherwise
> > > >> + *          -ENOMEM unable to allocate memory
> > > >> + *          -EINVAL buffer not allocated or too small
> > > >> + *
> > > >> + */
> > > >> +static ssize_t sure_admin_settings_read(struct file *filp, struct kobject
> > > >> *kobj,
> > > >> +                                    struct bin_attribute *attr, char *buf,
> > > >> loff_t off, size_t count)
> > > >> +{
> > > >> +    ssize_t ret;
> > > >> +
> > > >> +    /* clear the buffer when offset is pointing to the last position */
> > > >> +    if (off >= settings_buffer_size && settings_buffer_size > 0) {
> > > >> +            hp_bios_settings_free_buffer();
> > > >> +            return 0;
> > > >> +    }
> > > >> +
> > > >> +    /* clear the buffer whenever the read starts from the first position
> > > >> */
> > > >> +    if (off == 0 && settings_buffer_size > 0)
> > > >> +            hp_bios_settings_free_buffer();
> > > >> +
> > > >> +    if (settings_buffer_size == 0)
> > > >> +            hp_bios_settings_fill_buffer();
> > > >> +
> > > >> +    mutex_lock(&buf_mutex);
> > > >> +    ret = memory_read_from_buffer(buf, count, &off,
> > > >> hp_bios_settings_buffer,
> > > >> +                                  settings_buffer_size);
> > > >> +    mutex_unlock(&buf_mutex);
> > > >> +
> > > >> +    return ret;
> > > >> +}
> > > >> +
> > > >> +
> > > >> +/*
> > > >> + * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
> > > >> + *
> > > >> + * @p:   Unicode buffer address
> > > >> + * @str: string to convert to unicode
> > > >> + *
> > > >> + * Returns a void pointer to the buffer containing unicode string
> > > >> + */
> > > >> +static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
> > > >> +{
> > > >> +    int len = strlen(str);
> > > >> +
> > > >> +    /*
> > > >> +     * Add null character when reading an empty string
> > > >> +     */
> > > >> +    if (len == 0) {
> > > >> +            *p++ = 2;
> > > >> +            *p++ = (u8)0x00;
> > > >> +            return p;
> > > >> +    }
> > > >> +    *p++ = len * 2;
> > > >> +    utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
> > > >> +    p += len;
> > > >> +
> > > >> +    return p;
> > > >> +}
> > > >> +
> > > >> +/*
> > > >> + * hp_wmi_set_bios_setting - Set setting's value in BIOS
> > > >> + *
> > > >> + * @input_buffer: Input buffer address
> > > >> + * @input_size:   Input buffer size
> > > >> + *
> > > >> + * Returns: Count of unicode characters written to BIOS if successful,
> > > >> otherwise
> > > >> + *          -ENOMEM unable to allocate memory
> > > >> + *          -EINVAL buffer not allocated or too small
> > > >> + */
> > > >> +static int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
> > > >> +{
> > > >> +    union acpi_object *obj;
> > > >> +    struct acpi_buffer input = {input_size, input_buffer};
> > > >> +    struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
> > > >> +    int ret = 0;
> > > >> +
> > > >> +    ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID, 0, 1,
> > > >> &input, &output);
> > > >> +
> > > >> +    obj = output.pointer;
> > > >> +    if (!obj)
> > > >> +            return -EINVAL;
> > > >> +
> > > >> +    if (obj->type != ACPI_TYPE_INTEGER)
> > > >> +            ret = -EINVAL;
> > > >> +
> > > >> +    ret = obj->integer.value;
> > > >> +    kfree(obj);
> > > >> +    return ret;
> > > >> +}
> > > >> +
> > > >> +/* Sure Admin Functions */
> > > >> +
> > > >> +#define UTF_PREFIX                  ((unsigned char *)"<utf-16/>")
> > > >> +#define BEAM_PREFIX                 ((unsigned char
> > > >> *)"<BEAM/>")
> > > >> +
> > > >> +/*
> > > >> + * sure_admin_settings_write - Write the contents of a formatted file
> > > >> + *                               with settings and performs the logic
> > > >> + *                               to change any settings in BIOS.
> > > >> + *
> > > >> + * @filp:  Pointer to file of settings to be written to BIOS
> > > >> + * @kobj:  Pointer to a kernel object of things that show up as directory
> > in
> > > >> the sysfs filesystem.
> > > >> + * @attr:  Pointer to list of attributes for the write operation
> > > >> + * @buf:   Pointer to buffer
> > > >> + * @off:   File current offset
> > > >> + * @count: Buffer size
> > > >> + *
> > > >> + *
> > > >> + * Returns the count of unicode characters written to BIOS if
> > successful,
> > > >> otherwise
> > > >> + *          -ENOMEM unable to allocate memory
> > > >> + *          -EINVAL buffer not allocated or too small
> > > >> + *
> > > >> + */
> > > >> +static ssize_t sure_admin_settings_write(struct file *filp, struct kobject
> > > >> *kobj,
> > > >> +                    struct bin_attribute *attr, char *buf, loff_t off, size_t
> > > >> count)
> > > >> +{
> > > >> +    int status = 0;
> > > >> +    char *part = NULL;
> > > >> +    int part_len = 0;
> > > >> +    unsigned short *buffer = NULL;
> > > >> +    unsigned short *tmpstr = NULL;
> > > >> +    int buffer_size = (count + strlen(UTF_PREFIX)) * sizeof(unsigned
> > > >> short);
> > > >> +
> > > >> +    buffer = kmalloc(buffer_size, GFP_KERNEL);
> > > >> +    if (!buffer)
> > > >> +            return -ENOMEM;
> > > >> +
> > > >> +    tmpstr = buffer;
> > > >> +    part = strsep(&buf, ",");
> > > >> +    if (!part) {
> > > >> +            status = -EINVAL;
> > > >> +            goto out_free;
> > > >> +    }
> > > >> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > > >> +    part = strsep(&buf, ",");
> > > >> +    if (!part) {
> > > >> +            status = -EINVAL;
> > > >> +            goto out_free;
> > > >> +    }
> > > >> +
> > > >> +    /* Add extra buffer space when encountering an empty string */
> > > >> +    if (!strlen(part))
> > > >> +            buffer_size += sizeof(unsigned short);
> > > >> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > > >> +    part = strsep(&buf, ",");
> > > >> +    if (!part) {
> > > >> +            status = -EINVAL;
> > > >> +            goto out_free;
> > > >> +    }
> > > >> +    part_len = strlen(part) - 1;
> > > >> +    part[part_len] = '\0';
> > > >> +
> > > >> +    if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
> > > >> +           /*
> > > >> +            * BEAM_PREFIX is append to buffer when a signature
> > > >> +            * is provided and Sure Admin is enabled in BIOS
> > > >> +            */
> > > >> +            // BEAM_PREFIX found, convert part to unicode
> > > >> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > > >> +            // decrease buffer size allocated initially for UTF_PREFIX
> > > >> +            buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
> > > >> +    } else {
> > > >> +            /*
> > > >> +             * UTF-16 prefix is append to the * buffer when a BIOS
> > > >> +             * admin password is configured in BIOS
> > > >> +             */
> > > >> +
> > > >> +            // append UTF_PREFIX to part and then convert it to unicode
> > > >> +            part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
> > > >> +            if (!part)
> > > >> +                    goto out_free;
> > > >> +
> > > >> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > > >> +            kfree(part);
> > > >> +    }
> > > >> +
> > > >> +    part = strsep(&buf, ",");
> > > >> +    if (part) {
> > > >> +            status = -EINVAL;
> > > >> +            goto out_free;
> > > >> +    }
> > > >> +    status = hp_wmi_set_bios_setting(buffer, buffer_size);
> > > >> +    if (ACPI_FAILURE(status))
> > > >> +            status = -EINVAL;
> > > >> +
> > > >> +out_free:
> > > >> +    kfree(buffer);
> > > >> +    if (ACPI_SUCCESS(status))
> > > >> +            return count;
> > > >> +    return status;
> > > >> +}
> > > >> +
> > > >> +HPWMI_BINATTR_RW(sure_admin, settings, 0);
> > > >> +
> > > >> +static struct bin_attribute *sure_admin_binattrs[] = {
> > > >> +    &sure_admin_settings,
> > > >> +    NULL,
> > > >> +};
> > > >> +
> > > >> +static const struct attribute_group sure_admin_group = {
> > > >> +    .name = "sure_admin",
> > > >> +    .bin_attrs = sure_admin_binattrs,
> > > >> +};
> > > >> +
> > > >>  static DEVICE_ATTR_RO(display);
> > > >>  static DEVICE_ATTR_RO(hddtemp);
> > > >>  static DEVICE_ATTR_RW(als);
> > > >> @@ -1050,6 +2026,7 @@ static const struct attribute_group
> > > >> *hp_wmi_groups[] = {
> > > >>      &hp_wmi_group,
> > > >>      &spm_group,
> > > >>      &sure_start_group,
> > > >> +    &sure_admin_group,
> > > >>      NULL,
> > > >>  };
> > > >>
> > > >> --
> > > >> 2.25.1
> > >

Mario Limonciello April 7, 2022, 7:17 p.m. UTC | #6

[Public]

> -----Original Message-----
> From: Jorge Lopez <[e-mail]>
> Sent: Thursday, April 7, 2022 08:45
> To: Limonciello, Mario <[e-mail]>
> Cc: Hans de Goede <[e-mail]>; platform-driver-
> [e-mail]
> Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
> 
> Hans, Mario,
> 
> The code links make references to code that implements the new
> interfaces but there’s
> still code in the kernel that uses the old ones.  I do agree we should
> be forward looking
> and want to be good participants in the kernel development, but can’t
> let our immediate
> business needs be impacted with opportunities to enhance the driver to
> take advantage
> of the latest kernel features.
> 

Keep in mind that from an upstream kernel perspective this driver is "new".
There is no requirements from the upstream perspective to
keep your old interfaces in place from when it was out of tree.

Requirements like this start when the driver is in tree.
https://www.kernel.org/doc/html/latest/admin-guide/abi-stable.html

> Rewriting those security features will impact customer business
> datelines requiring
> HP to provide private releases as the kernel version changes.   The
> requested changes
> will impact products in the market and HP ability to help customers to
> migrate to Linux
> from Windows products.
> 
> It is because of the immediate business needs, avoiding impacting our
> customers/products,
> and rewriting  enhancements to the driver that I need to propose an
> interim solution.

Right, get it upstream and it's less work, of course 

Jorge Lopez April 7, 2022, 8:57 p.m. UTC | #7

On Thu, Apr 7, 2022 at 2:17 PM Limonciello, Mario
<[e-mail]> wrote:
>
> [Public]
>
> > -----Original Message-----
> > From: Jorge Lopez <[e-mail]>
> > Sent: Thursday, April 7, 2022 08:45
> > To: Limonciello, Mario <[e-mail]>
> > Cc: Hans de Goede <[e-mail]>; platform-driver-
> > [e-mail]
> > Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
> >
> > Hans, Mario,
> >
> > The code links make references to code that implements the new
> > interfaces but there’s
> > still code in the kernel that uses the old ones.  I do agree we should
> > be forward looking
> > and want to be good participants in the kernel development, but can’t
> > let our immediate
> > business needs be impacted with opportunities to enhance the driver to
> > take advantage
> > of the latest kernel features.
> >
>
> Keep in mind that from an upstream kernel perspective this driver is "new".
> There is no requirements from the upstream perspective to
> keep your old interfaces in place from when it was out of tree.
>
> Requirements like this start when the driver is in tree.
> https://www.kernel.org/doc/html/latest/admin-guide/abi-stable.html
>
Thank you for the link and explanation regarding the kernel
perspective for the state of the driver.

> > Rewriting those security features will impact customer business
> > datelines requiring
> > HP to provide private releases as the kernel version changes.   The
> > requested changes
> > will impact products in the market and HP ability to help customers to
> > migrate to Linux
> > from Windows products.
> >
> > It is because of the immediate business needs, avoiding impacting our
> > customers/products,
> > and rewriting  enhancements to the driver that I need to propose an
> > interim solution.
>
> Right, get it upstream and it's less work, of course 

Hans de Goede April 8, 2022, 9:21 a.m. UTC | #8

Hi Jorge,

On 4/7/22 15:44, Jorge Lopez wrote:
> Hans, Mario,
> 
> The code links make references to code that implements the new
> interfaces but there’s
> still code in the kernel that uses the old ones.

I'm not sure what you mean with "uses the old ones" there never
has been any kernel drivers for changing BIOS settings before
the dell and lenovo drivers were merged.

Sure there are generic mechanisms like chardev-s and ioctls which
are used for a whole bunch of things. But AFAIK there never was
an API specifically for changing BIOS settings before.

> I do agree we should
> be forward looking
> and want to be good participants in the kernel development, but can’t
> let our immediate
> business needs be impacted with opportunities to enhance the driver to
> take advantage
> of the latest kernel features.
> 
> Rewriting those security features will impact customer business
> datelines requiring
> HP to provide private releases as the kernel version changes.   The
> requested changes
> will impact products in the market and HP ability to help customers to
> migrate to Linux
> from Windows products.

This sounds like you are saying that you are already shipping
a version of the driver with the non-standard API to customers.
Shipping code to customers before even proposing it upstream is
HP own choice and the results of that as such are HP's
responsibility.

You cannot just say we are already shipping this so we need
the upstream kernel to support this non standard API, that is
not how upstream kernel development works.

I realize that HP is new to working directly with the upstream kernel
community and I realize that being told that the API which you are
already using cannot be used for upstreaming your driver is not what
you want to hear.

But that does not change that I cannot accept a driver which does not
implement the standard API which the upstream kernel community has
agreed upon for this functionality.

Or as Mario very elegantly put it:

'Keep in mind that from an upstream kernel perspective this driver is "new".
There is no requirements from the upstream perspective to
keep your old interfaces in place from when it was out of tree.'

> It is because of the immediate business needs, avoiding impacting our
> customers/products,
> and rewriting  enhancements to the driver that I need to propose an
> interim solution.
> 
> My proposal is to introduce a read/write value accessible in the user
> space to control how
> the driver reports and handles BIOS settings and values.  The new
> configuration features
> will be gradually disabled  as they are converted to use the standardized API.
> It is like the configuration flag used to overcome the tablet detection problem
> introduced in the past.   The changes solely affect the HP WMI driver.
> This option will help us
> move forward for this release and give us time to make the necessary
> changes to both
> the driver and support applications.
> 
> Please let me know if this is a viable interim solution.

First of all to be very clear, any code going upstream must support
the standard API:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-class-firmware-attributes

from day one. I'm not really enthusiastic about the concept of also
supporting the API which you have been using out of tree so far, but
I guess that Mario's suggestion to offer a Kconfig option which
when enabled offers this API under debugfs might be an acceptible
compromise. I would need to see the actual code for that though to
see if this is acceptable.

And there would need to be a clear cut-of date document after which
the code to support the old API will be removed.

> If it is not possible, I need to ask where the actual written
> requirement is found so I can
> include them in the business justification for changes and release
> delays to management.

I'm not sure if this is written down somewhere, but certainly
you will agree that if you were submitting a driver for a soundcard
that that should use the existing ALSA userspace API for sound so
that it would just work with the existing userspace sound support.

This is the same. If an existing standardized userspace API exists
for a certain functionality then that userspace API _must_ be used,
AFAIK this is not explictly written down anywhere because it is just
very much common sense.

Regards,

Hans






> On Tue, Apr 5, 2022 at 12:13 PM Limonciello, Mario
> <[e-mail]> wrote:
>>
>> [Public]
>>
>>
>>
>>> -----Original Message-----
>>> From: Jorge Lopez <[e-mail]>
>>> Sent: Tuesday, April 5, 2022 11:52
>>> To: Hans de Goede <[e-mail]>
>>> Cc: Limonciello, Mario <[e-mail]>; platform-driver-
>>> [e-mail]
>>> Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
>>>
>>> Hi Hans,
>>>
>>> On Tue, Apr 5, 2022 at 6:54 AM Hans de Goede <[e-mail]>
>>> wrote:
>>>>
>>>> Hi,
>>>>
>>>> On 4/4/22 23:59, Limonciello, Mario wrote:
>>>>> [Public]
>>>>>
>>>>>
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Jorge Lopez <[e-mail]>
>>>>>> Sent: Monday, April 4, 2022 15:36
>>>>>> To: [e-mail]
>>>>>> Subject: [PATCH v1 5/6] Sure Admin Security Feature
>>>>>>
>>>>>> HP Commercial PC's have several BIOS settings that control its
>>>>>> behaviour and capabilities, many of which are related to security.  To
>>>>>> prevent unauthorized changes to these settings, the system can be
>>>>>> configured to use a Sure Admin cryptographic signature-based
>>>>>> authorization string that the BIOS will use to verify authorization to
>>>>>> modify the setting. Behind the scenes, Sure Admin uses Secure
>>> Platform
>>>>>> Management (SPM) and WMI
>>>>>>
>>>>>> 'settings' is a file associated with Sure Admin. BIOS settings can be
>>>>>> read or written through the Sure Admin settings file in sysfs
>>>>>>
>>>>>>      /sys/devices/platform/hp-wmi/sure_admin/settings
>>>>>>
>>>>>> Expected data format to update BIOS setting
>>>>>>
>>>>>>      [BIOS setting],[new value],[auth token]
>>>>>>
>>>>>> Sample settings reported data
>>>>>>
>>>>>>      {
>>>>>>              "Class": "HPBIOS_BIOSEnumeration",
>>>>>>              "Name": "USB Storage Boot",
>>>>>>              "Path": "\\Advanced\\Boot Options",
>>>>>>              "IsReadOnly": 0,
>>>>>>              ...
>>>>>>              "Value": "Enable",
>>>>>>              "Size": 2,
>>>>>>              "PossibleValues": [
>>>>>>                      "Disable",
>>>>>>                      "Enable"
>>>>>>              ]
>>>>>>      }
>>>>>>
>>>>>
>>>>> This sounds like it has re-invented /sys/class/firmware-attributes.
>>>>>
>>>>> Shouldn't you adopt that API?
>>>>
>>>> I fully agree. Jorge as I already indicated in our off-list
>>>> conversation when you initially started working on this
>>>> feature, we already have a standardized API for querying/changing
>>>> BIOS settings from within Linux:
>>>>
>>>
>>> I agree that changing the BIOS settings from within Linux could
>>> utilize the new methodology,  I will need to look closely at the
>>> requirements before I can proceed to make the changes.
>>> Keep in mind authentication of the values is done by BIOS.  No Linux
>>> process validates any data name, value, or auth token; only BIOS.  All
>>> data written to the sysfs file is not validated, it is just forward to
>>> BIOS.  See spm_kek_store and spm_sk_store functions.
>>
>> That's fine, and it's a safer design to have BIOS validate it.
>>
>>> One point I must make clear when updating BIOS settings.  any  NOT
>>> read-only BIOS settings can be changed by the application at any time.
>>>    This list of settings changes from one system to another.
>>
>> Right.
>>
>>>
>>> I am in disagreement with reading the settings.  hp-wmi does not read
>>> one value at a time. It reads all values exposed by BIOS.  See
>>> attached sample output.
>>
>> The settings can all be read at initialization time for the driver and cached
>> then.
>>
>>> The method for how all BIOS settings are reported needs to match the
>>> method how Windows products do it.  It is a requirement to start
>>> migrating customers from Windows to Linux while minimizing how BIOS
>>> data is reported.
>>
>> Because we have a standardized API in Linux for this, I think it's best to abstract
>> this behind a userspace application/script.  If they expect to see it in the format you
>> showed, the userspace application can take the data from Linux and package it that
>> way.
>>
>> You'll have richer libraries and languages and tools to work from when doing this too.
>> It should make it a lot less painful.
>>
>>>
>>> I will investigate the new API and bring it to the team's attention.
>>>
>>>>
>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
>>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
>>> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
>>> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
>>> f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
>>> 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
>>> C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
>>> &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
>>> D&amp;reserved=0
>>>>
>>>> and any new code (such as this patch) which implements BIOS
>>>> setting changing MUST follow this standardized API (extending
>>>> it where necessary).
>>>>
>>>> I'm sorry but this patch is not acceptable in its current form,
>>>> it needs to be *completely rewritten* to implement:
>>>>
>>>>
>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
>>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
>>> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
>>> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
>>> f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
>>> 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
>>> C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
>>> &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
>>> D&amp;reserved=0
>>>>
>>>> See:
>>>>
>>>>
>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
>>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
>>> 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fdell%2Fdell-wmi-
>>> sysman&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8f
>>> ea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%
>>> 7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
>>> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
>>> mp;sdata=z5jmH7ECYBeLcndQ2vfHaUuyE04Eaf1Lymh6BjnyJ%2Fk%3D&amp;r
>>> eserved=0
>>>>
>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
>>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
>>> 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fthink-
>>> lmi.c&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea
>>> 104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C
>>> 0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLj
>>> AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;
>>> sdata=5n6w9LEB2iWpj1cOQP6Ngz94AqP1Bu4vu8T0EdN%2FThU%3D&amp;re
>>> served=0
>>>>
>>>> for example code / for 2 drivers from other vendors already
>>>> implementing this.
>>>>
>>>> The same applies to the:
>>>>
>>>> "[PATCH v1 3/6] Secure Platform Management Security Feature"
>>>>
>>>> this needs to be implemented as
>>>> a /sys/class/firmware-attributes/*/authentication/
>>>> authentication method, see for example these Lenovo specific
>>>> addition to the /sys/class/firmware-attributes/*/authentication/
>>>> userspace API for similar functionality on Lenovo Think* devices:
>>>>
>>>>
>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
>>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
>>> 2Fcommit%2F%3Fid%3D06384573a3e8335ac6797577e545c33dbf91b490&amp;
>>> data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea1040342827
>>> 08da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C63784
>>> 7743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLC
>>> JQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=eldS
>>> 4H3Z%2BAyL%2FG%2FO9W9rDGC37yh5sGgtUhpKdUAoSmA%3D&amp;reser
>>> ved=0
>>>>
>>>> I'll merge patches 1-2 sometime this week since those are
>>>> fine and it will be good to have those "out of the way",
>>>> but the rest of the series will need to be rewritten
>>>> taken the above comments into account.
>>>
>>> v1-0003-Sure-Start-Security-Feature.patch  reports the number of audit
>>> logs available and reports them when read.    it does not read/write
>>> BIOS settings hence it does not fall within the same category as
>>> patches v1-0002-Secure-Platform-Management-Security-Feature.patch and
>>> v1-0004-Sure-Admin-Security-Feature.patch
>>> Do you agree?
>>>
>>>>
>>>> Regards,
>>>>
>>>> Hans
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>>
>>>>>> This feature requires "Update hp_wmi_group to simplify feature
>>>>>> addition" patch.
>>>>>>
>>>>>> All changes were validated on a HP ZBook Workstation,
>>>>>> HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
>>>>>>
>>>>>> Signed-off-by: Jorge Lopez <[e-mail]>
>>>>>>
>>>>>> ---
>>>>>> Based on the latest platform-drivers-x86.git/for-next
>>>>>> ---
>>>>>>  drivers/platform/x86/hp-wmi.c | 977
>>>>>> ++++++++++++++++++++++++++++++++++
>>>>>>  1 file changed, 977 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-
>>> wmi.c
>>>>>> index 918e3eaf1b67..b72ca18b77a6 100644
>>>>>> --- a/drivers/platform/x86/hp-wmi.c
>>>>>> +++ b/drivers/platform/x86/hp-wmi.c
>>>>>> @@ -27,6 +27,7 @@
>>>>>>  #include <linux/rfkill.h>
>>>>>>  #include <linux/string.h>
>>>>>>  #include <linux/dmi.h>
>>>>>> +#include <linux/nls.h>
>>>>>>
>>>>>>  MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
>>>>>>  MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
>>>>>> @@ -37,8 +38,16 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-
>>>>>> 3D44E2C707E4");
>>>>>>
>>>>>>  #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-
>>> ACCDC67EF61C"
>>>>>>  #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-
>>> 3D44E2C707E4"
>>>>>> +
>>>>>>  #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
>>>>>>
>>>>>> +#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-
>>> 6A1B8106F83C"
>>>>>> +#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-
>>>>>> E293ADB9BF05"
>>>>>> +#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-
>>>>>> 4A3C09E75133"
>>>>>> +#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-A0E0-
>>>>>> 7045CB4DA745"
>>>>>> +#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-
>>>>>> 015176049E2D"
>>>>>> +#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-951D-
>>>>>> C7CB9B4B8D5E"
>>>>>> +
>>>>>>  /* DMI board names of devices that should use the omen specific path
>>> for
>>>>>>   * thermal profiles.
>>>>>>   * This was obtained by taking a look in the windows omen command
>>> center
>>>>>> @@ -1025,6 +1034,973 @@ static const struct attribute_group
>>>>>> sure_start_group = {
>>>>>>      .attrs = sure_start_attrs,
>>>>>>  };
>>>>>>
>>>>>> +
>>>>>> +static int convert_hexstr_to_str(char **hex, int input_len, char **str,
>>> int
>>>>>> *len)
>>>>>> +{
>>>>>> +    int ret = 0;
>>>>>> +    int new_len = 0;
>>>>>> +    char tmp[] = "0x00";
>>>>>> +    char *input = *hex;
>>>>>> +    char *new_str = NULL;
>>>>>> +    int  ch;
>>>>>> +    int i;
>>>>>> +
>>>>>> +    if (input_len <= 0 || hex == NULL || str == NULL || len == NULL)
>>>>>> +            return -EINVAL;
>>>>>> +
>>>>>> +    *len = 0;
>>>>>> +    *str = NULL;
>>>>>> +
>>>>>> +    new_str = kmalloc(input_len, GFP_KERNEL);
>>>>>> +    if (!new_str)
>>>>>> +            return -ENOMEM;
>>>>>> +
>>>>>> +    for (i = 0; i < input_len; i += 5) {
>>>>>> +            strncpy(tmp, input + i, strlen(tmp));
>>>>>> +            ret = kstrtoint(tmp, 16, &ch);
>>>>>> +            if (ret) {
>>>>>> +                    new_len = 0;
>>>>>> +                    break;
>>>>>> +            }
>>>>>> +
>>>>>> +            if (ch == '\\')
>>>>>> +                    new_str[new_len++] = '\\';
>>>>>> +
>>>>>> +            new_str[new_len++] = ch;
>>>>>> +            if (ch == '\0')
>>>>>> +                    break;
>>>>>> +    }
>>>>>> +
>>>>>> +    if (new_len) {
>>>>>> +            new_str[new_len] = '\0';
>>>>>> +            *str = krealloc(new_str, (new_len + 1) * sizeof(char),
>>>>>> GFP_KERNEL);
>>>>>> +            if (*str)
>>>>>> +                    *len = new_len;
>>>>>> +            else
>>>>>> +                    ret = -ENOMEM;
>>>>>> +    }
>>>>>> +
>>>>>> +    if (ret)
>>>>>> +            kfree(new_str);
>>>>>> +    return ret;
>>>>>> +}
>>>>>> +
>>>>>> +/*
>>>>>> + * hp_wmi_get_setting_object() - Get an ACPI object by GUID and
>>> instance
>>>>>> + *
>>>>>> + * @guid:   GUID associated with the ACPI list of managed objects
>>>>>> + * @instance:       Instance index to query on the ACPI list
>>>>>> + * @obj:    The output ACPI object of type ACPI_TYPE_PACKAGE
>>>>>> + *          or ACPI_TYPE_BUFFER (freed by the callee)
>>>>>> + *
>>>>>> + * Returns  zero on success.  Otherwise,an error inherited from
>>>>>> + *          wmi_query_block(). It returns a obj by parameter if
>>>>>> + *          the query returned object of type buffer or package,
>>>>>> + *          otherwise, a null obj is returned.
>>>>>> + *
>>>>>> + * Note: obj should be freed by the callee once it is finished working
>>> with it
>>>>>> + */
>>>>>> +static int hp_wmi_get_setting_object(char *guid, int instance,
>>>>>> +                            union acpi_object **obj)
>>>>>> +{
>>>>>> +    struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER, NULL
>>>>>> };
>>>>>> +    union acpi_object *tmp = NULL;
>>>>>> +    int ret;
>>>>>> +
>>>>>> +    ret = wmi_query_block(guid, instance, &output);
>>>>>> +    if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
>>>>>> +            tmp = output.pointer;
>>>>>> +            if (tmp->type == ACPI_TYPE_BUFFER || tmp->type ==
>>>>>> ACPI_TYPE_PACKAGE)
>>>>>> +                    *obj = output.pointer;
>>>>>> +            else {
>>>>>> +                    kfree(tmp);
>>>>>> +                    *obj = NULL;
>>>>>> +            }
>>>>>> +    }
>>>>>> +
>>>>>> +    return ret;
>>>>>> +}
>>>>>> +
>>>>>> +
>>>>>> +static int get_string_from_buffer(u16 **buffer, char **str)
>>>>>> +{
>>>>>> +    u16 *ptr = *buffer;
>>>>>> +    u16 ptrlen;
>>>>>> +
>>>>>> +    u16 size;
>>>>>> +    int i;
>>>>>> +    char *output = NULL;
>>>>>> +    int escape = 0;
>>>>>> +
>>>>>> +    ptrlen = *(ptr++);
>>>>>> +    size = ptrlen / 2;
>>>>>> +
>>>>>> +    if (size == 0)
>>>>>> +            goto cleanup_exit;
>>>>>> +
>>>>>> +    for (i = 0; i < size; i++)
>>>>>> +            if (ptr[i] == '\\')
>>>>>> +                    escape++;
>>>>>> +
>>>>>> +    size += escape;
>>>>>> +    *str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
>>>>>> +    if (!*str)
>>>>>> +            return -ENOMEM;
>>>>>> +
>>>>>> +    output = *str;
>>>>>> +
>>>>>> +    /*
>>>>>> +     * convert from UTF-16 unicode to ASCII
>>>>>> +     */
>>>>>> +    utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output, size);
>>>>>> +
>>>>>> +    if (escape == 0) {
>>>>>> +            ptr += (ptrlen / 2);
>>>>>> +            goto cleanup_exit;
>>>>>> +    }
>>>>>> +    /*
>>>>>> +     * Convert escape characters only when found
>>>>>> +     */
>>>>>> +    for (i = 0; i < size; i++) {
>>>>>> +            if (*ptr == '\\')
>>>>>> +                    output[i++] = '\\';
>>>>>> +            output[i] = *ptr;
>>>>>> +            ptr++;
>>>>>> +    }
>>>>>> +
>>>>>> +cleanup_exit:
>>>>>> +    *buffer = ptr;
>>>>>> +    return 0;
>>>>>> +}
>>>>>> +
>>>>>> +static int get_integer_from_buffer(int **buffer, int *integer)
>>>>>> +{
>>>>>> +    int *ptr = PTR_ALIGN(*buffer, 4);
>>>>>> +    *integer = *(ptr++);
>>>>>> +    *buffer = ptr;
>>>>>> +    return 0;
>>>>>> +}
>>>>>> +
>>>>>> +
>>>>>> +// Sure Admin functions
>>>>>> +enum hp_wmi_data_type {
>>>>>> +    HPWMI_STRING_TYPE,
>>>>>> +    HPWMI_INTEGER_TYPE,
>>>>>> +    HPWMI_ENUMERATION_TYPE,
>>>>>> +    HPWMI_ORDEREDLIST_TYPE,
>>>>>> +    HPWMI_PASSWORD_TYPE,
>>>>>> +};
>>>>>> +
>>>>>> +#define HP_WMI_COMMON_ELEMENTS      \
>>>>>> +    "Name", \
>>>>>> +    "Value",        \
>>>>>> +    "Path", \
>>>>>> +    "IsReadOnly",   \
>>>>>> +    "DisplayInUI",  \
>>>>>> +    "RequiresPhysicalPresence",     \
>>>>>> +    "Sequence",     \
>>>>>> +    "PrerequisiteSize",     \
>>>>>> +    "SecurityLevel"
>>>>>> +
>>>>>> +const char *hp_wmi_string_elements[] = {
>>>>>> +    HP_WMI_COMMON_ELEMENTS,
>>>>>> +    "MinLength",
>>>>>> +    "MaxLength"
>>>>>> +};
>>>>>> +
>>>>>> +const char *hp_wmi_integer_elements[] = {
>>>>>> +    HP_WMI_COMMON_ELEMENTS,
>>>>>> +    "LowerBound",
>>>>>> +    "UpperBound",
>>>>>> +    "IntValue"
>>>>>> +};
>>>>>> +
>>>>>> +const char *hp_wmi_enumeration_elements[] = {
>>>>>> +    HP_WMI_COMMON_ELEMENTS,
>>>>>> +    "CurrentValue",
>>>>>> +    "Size"
>>>>>> +};
>>>>>> +
>>>>>> +const char *hp_wmi_orderedlist_elements[] = {
>>>>>> +    HP_WMI_COMMON_ELEMENTS,
>>>>>> +    "Size"
>>>>>> +};
>>>>>> +
>>>>>> +const char *hp_wmi_password_elements[] = {
>>>>>> +    HP_WMI_COMMON_ELEMENTS,
>>>>>> +    "MinLength",
>>>>>> +    "MaxLength",
>>>>>> +    "Size",
>>>>>> +    "SupportedEncoding",
>>>>>> +    "IsSet"
>>>>>> +};
>>>>>> +
>>>>>> +const char **hp_wmi_elements[] = {
>>>>>> +    hp_wmi_string_elements,
>>>>>> +    hp_wmi_integer_elements,
>>>>>> +    hp_wmi_enumeration_elements,
>>>>>> +    hp_wmi_orderedlist_elements,
>>>>>> +    hp_wmi_password_elements
>>>>>> +};
>>>>>> +
>>>>>> +const int hp_wmi_elements_count[] = {
>>>>>> +    ARRAY_SIZE(hp_wmi_string_elements),
>>>>>> +    ARRAY_SIZE(hp_wmi_integer_elements),
>>>>>> +    ARRAY_SIZE(hp_wmi_enumeration_elements),
>>>>>> +    ARRAY_SIZE(hp_wmi_orderedlist_elements),
>>>>>> +    ARRAY_SIZE(hp_wmi_password_elements)
>>>>>> +};
>>>>>> +
>>>>>> +const char *hp_wmi_classes[] = {
>>>>>> +    "HPBIOS_BIOSString",
>>>>>> +    "HPBIOS_BIOSInteger",
>>>>>> +    "HPBIOS_BIOSEnumeration",
>>>>>> +    "HPBIOS_BIOSOrderedList",
>>>>>> +    "HPBIOS_BIOSPassword"
>>>>>> +};
>>>>>> +
>>>>>> +static DEFINE_MUTEX(buf_mutex);
>>>>>> +static int settings_buffer_size;
>>>>>> +static int buf_alloc_size;
>>>>>> +static char *hp_bios_settings_buffer;
>>>>>> +
>>>>>> +
>>>>>> +static int append_package_elements_to_buffer(union acpi_object
>>> *obj,
>>>>>> +                                         char *buf, int alloc_size, enum
>>>>>> hp_wmi_data_type type)
>>>>>> +{
>>>>>> +    int i;
>>>>>> +    union acpi_object *pobj = NULL;
>>>>>> +    char *value = NULL;
>>>>>> +    int value_len;
>>>>>> +    char *tmpstr = NULL;
>>>>>> +    char *part_tmp = NULL;
>>>>>> +    int tmp_len = 0;
>>>>>> +    char *part = NULL;
>>>>>> +    int status = 0;
>>>>>> +    int size = 0;
>>>>>> +    int buf_size;
>>>>>> +
>>>>>> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
>>>>>> +            return -EINVAL;
>>>>>> +
>>>>>> +    if (obj->type != ACPI_TYPE_PACKAGE)
>>>>>> +            return -EINVAL;
>>>>>> +
>>>>>> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
>>>>>> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
>>>>>> hp_wmi_classes[type]);
>>>>>> +
>>>>>> +    for (i = 0; i < 3; i++) {
>>>>>> +            pobj = &(obj->package.elements[i]);
>>>>>> +            if (pobj->type == ACPI_TYPE_STRING) {
>>>>>> +                    status = convert_hexstr_to_str(&pobj-
>>>>>>> string.pointer,
>>>>>> +                                                   pobj->string.length,
>>>>>> &value, &value_len);
>>>>>> +                    if (ACPI_FAILURE(status))
>>>>>> +                            continue;
>>>>>> +                    /*
>>>>>> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
>>>>>> since
>>>>>> +                     * 'CurrentValue' is reported.
>>>>>> +                     */
>>>>>> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
>>>>>> +                            buf_size = snprintf(buf, alloc_size,
>>>>>> +                                                "%s\t\"%s\": \"%s\",\n",
>>>>>> +                                                buf,
>>>>>> +
>>>>>> hp_wmi_elements[type][i], value);
>>>>>> +
>>>>>> +            }
>>>>>> +            kfree(value);
>>>>>> +            value = NULL;
>>>>>> +    }
>>>>>> +
>>>>>> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
>>>>>> +            pobj = &(obj->package.elements[i]);
>>>>>> +
>>>>>> +            if (type == HPWMI_ENUMERATION_TYPE &&
>>>>>> +                i == 9 &&
>>>>>> +                pobj->type == ACPI_TYPE_STRING) {
>>>>>> +                    /*
>>>>>> +                     * Report "CurrentValue" as "Value"
>>>>>> +                     */
>>>>>> +                    status = convert_hexstr_to_str(&pobj-
>>>>>>> string.pointer,
>>>>>> +                                                   pobj->string.length,
>>>>>> +                                                   &value, &value_len);
>>>>>> +                    if (ACPI_FAILURE(status))
>>>>>> +                            continue;
>>>>>> +
>>>>>> +                    buf_size = snprintf(buf, alloc_size,
>>>>>> +                                        "%s\t\"Value\": \"%s\",\n",
>>>>>> +                                        buf, value);
>>>>>> +                    kfree(value);
>>>>>> +                    value = NULL;
>>>>>> +
>>>>>> +            } else if (type == HPWMI_PASSWORD_TYPE &&
>>>>>> +                       i == 12 &&
>>>>>> +                       pobj->type == ACPI_TYPE_STRING) {
>>>>>> +                    /*
>>>>>> +                     * Report list of "SupportEncoding"
>>>>>> +                     *
>>>>>> +                     *      "SupportedEncoding": [
>>>>>> +                     *              "utf-16"
>>>>>> +                     *      ],
>>>>>> +                     *
>>>>>> +                     */
>>>>>> +
>>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
>>>>>> +                                        buf, hp_wmi_elements[type][i]);
>>>>>> +                    while (size--) {
>>>>>> +                            pobj = &(obj->package.elements[i]);
>>>>>> +                            status = convert_hexstr_to_str(&pobj-
>>>>>>> string.pointer,
>>>>>> +                                                           pobj-
>>>>>>> string.length,
>>>>>> +                                                           &value,
>>>>>> &value_len);
>>>>>> +                            if (ACPI_FAILURE(status))
>>>>>> +                                    continue;
>>>>>> +
>>>>>> +                            if (size) {
>>>>>> +                                    buf_size = snprintf(buf, alloc_size,
>>>>>> +                                                        "%s\t\t\"%s\",\n",
>>>>>> buf, value);
>>>>>> +                                    i++;
>>>>>> +                            } else
>>>>>> +                                    buf_size = snprintf(buf, alloc_size,
>>>>>> +                                                        "%s\t\t\"%s\"\n",
>>>>>> buf, value);
>>>>>> +
>>>>>> +                            kfree(value);
>>>>>> +                            value = NULL;
>>>>>> +
>>>>>> +                    }
>>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>>>>>> +                    continue;
>>>>>> +
>>>>>> +            } else if (pobj->type == ACPI_TYPE_INTEGER) {
>>>>>> +                    /*
>>>>>> +                     * Report "PrerequisiteSize" and "Size" values
>>>>>> +                     *      ...
>>>>>> +                     *      "PrerequisiteSize": 1,
>>>>>> +                     *      ...
>>>>>> +                     *      "Size": 2,
>>>>>> +                     *      ...
>>>>>> +                     */
>>>>>> +                    if (i == 7)
>>>>>> +                            size = pobj->integer.value;
>>>>>> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
>>>>>> 9)
>>>>>> +                            size = pobj->integer.value;
>>>>>> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
>>>>>> == 10)
>>>>>> +                            size = pobj->integer.value;
>>>>>> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
>>>>>> 11)
>>>>>> +                            size = pobj->integer.value;
>>>>>> +
>>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
>>>>>> %lld,\n", buf,
>>>>>> +                                        hp_wmi_elements[type][i], pobj-
>>>>>>> integer.value);
>>>>>> +            }
>>>>>> +    }
>>>>>> +
>>>>>> +    if (type == HPWMI_ENUMERATION_TYPE) {
>>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\":
>>>>>> [\n", buf);
>>>>>> +            for (i = 0; i < size; i++) {
>>>>>> +                    pobj = &(obj->package.elements[i +
>>>>>> hp_wmi_elements_count[type]]);
>>>>>> +
>>>>>> +                    status = convert_hexstr_to_str(&pobj-
>>>>>>> string.pointer,
>>>>>> +                                                   pobj->string.length,
>>>>>> +                                                   &value, &value_len);
>>>>>> +                    if (ACPI_FAILURE(status))
>>>>>> +                            break;
>>>>>> +
>>>>>> +                    /*
>>>>>> +                     * Report list of "PossibleValues" of size
>>>>>> +                     * "Size"
>>>>>> +                     *      ...
>>>>>> +                     *      "Size": 2,
>>>>>> +                     *      "PossibleValues": [
>>>>>> +                     *                      "Disable",
>>>>>> +                     *                      "Enable"]
>>>>>> +                     */
>>>>>> +                    if (i == (size - 1))
>>>>>> +                            buf_size = snprintf(buf, alloc_size,
>>>>>> +                                                "%s\t\t\"%s\"\n", buf,
>>>>>> value);
>>>>>> +                    else
>>>>>> +                            buf_size = snprintf(buf, alloc_size,
>>>>>> +                                                "%s\t\t\"%s\",\n", buf,
>>>>>> value);
>>>>>> +                    kfree(value);
>>>>>> +                    value = NULL;
>>>>>> +            }
>>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>>>>>> +    }
>>>>>> +
>>>>>> +    if (type == HPWMI_ORDEREDLIST_TYPE) {
>>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n",
>>>>>> buf);
>>>>>> +            if (size <= 0)
>>>>>> +                    goto finish_ordered_list;
>>>>>> +
>>>>>> +            pobj = &(obj-
>>>>>>> package.elements[hp_wmi_elements_count[type]]);
>>>>>> +            status = convert_hexstr_to_str(&pobj->string.pointer,
>>>>>> +                                           pobj->string.length, &value,
>>>>>> &value_len);
>>>>>> +            if (ACPI_FAILURE(status))
>>>>>> +                    goto finish_ordered_list;
>>>>>> +
>>>>>> +            /*
>>>>>> +             * Ordered list data is stored in hex and comma separated
>>>>>> format
>>>>>> +             * Convert the data and split it to show each element
>>>>>> +             */
>>>>>> +            status = convert_hexstr_to_str(&value, value_len, &tmpstr,
>>>>>> &tmp_len);
>>>>>> +            if (ACPI_FAILURE(status))
>>>>>> +                    goto finish_ordered_list;
>>>>>> +
>>>>>> +            part_tmp = tmpstr;
>>>>>> +            part = strsep(&part_tmp, ",");
>>>>>> +            while (part) {
>>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"",
>>>>>> buf, part);
>>>>>> +                    part = strsep(&part_tmp, ",");
>>>>>> +                    if (part)
>>>>>> +                            buf_size = snprintf(buf, alloc_size, "%s,\n",
>>>>>> buf);
>>>>>> +                    else
>>>>>> +                            buf_size = snprintf(buf, alloc_size, "%s\n",
>>>>>> buf);
>>>>>> +            }
>>>>>> +    }
>>>>>> +
>>>>>> +finish_ordered_list:
>>>>>> +    if (type == HPWMI_ORDEREDLIST_TYPE)
>>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>>>>>> +
>>>>>> +    /*
>>>>>> +     * remove trailing comma
>>>>>> +     */
>>>>>> +    if (buf_size > 3)
>>>>>> +            buf[buf_size - 2] = ' ';
>>>>>> +
>>>>>> +    kfree(tmpstr);
>>>>>> +    kfree(value);
>>>>>> +    return snprintf(buf, alloc_size, "%s},\n", buf);
>>>>>> +}
>>>>>> +
>>>>>> +static int append_buffer_elements_to_buffer(union acpi_object *obj,
>>>>>> +                                        char *buf, int alloc_size, enum
>>>>>> hp_wmi_data_type type)
>>>>>> +{
>>>>>> +    int buf_size;
>>>>>> +    int status;
>>>>>> +    char *str = NULL;
>>>>>> +    int i;
>>>>>> +    int j;
>>>>>> +    int integer;
>>>>>> +    int size = 0;
>>>>>> +
>>>>>> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
>>>>>> +            return -EINVAL;
>>>>>> +
>>>>>> +    if (obj->type != ACPI_TYPE_BUFFER)
>>>>>> +            return -EINVAL;
>>>>>> +
>>>>>> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
>>>>>> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
>>>>>> hp_wmi_classes[type]);
>>>>>> +
>>>>>> +    for (i = 0; i < 3; i++) {
>>>>>> +            status = get_string_from_buffer((u16 **)&obj-
>>>>>>> buffer.pointer, &str);
>>>>>> +            if (ACPI_SUCCESS(status)) {
>>>>>> +                    /*
>>>>>> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
>>>>>> since
>>>>>> +                     * 'CurrentValue' is reported.
>>>>>> +                     */
>>>>>> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
>>>>>> +                            buf_size = snprintf(buf, alloc_size,
>>>>>> +                                                "%s\t\"%s\": \"%s\",\n",
>>>>>> +                                                buf,
>>>>>> +
>>>>>> hp_wmi_elements[type][i], str);
>>>>>> +            }
>>>>>> +            kfree(str);
>>>>>> +            str = NULL;
>>>>>> +
>>>>>> +    }
>>>>>> +
>>>>>> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
>>>>>> +            if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
>>>>>> +                    status = get_string_from_buffer((u16 **)&obj-
>>>>>>> buffer.pointer, &str);
>>>>>> +                    if (ACPI_SUCCESS(status)) {
>>>>>> +                            /*
>>>>>> +                             * Report "CurrentValue" as "Value"
>>>>>> +                             */
>>>>>> +                            buf_size = snprintf(buf, alloc_size,
>>>>>> +                                                "%s\t\"Value\": \"%s\",\n",
>>>>>> buf, str);
>>>>>> +                    }
>>>>>> +                    kfree(str);
>>>>>> +                    str = NULL;
>>>>>> +                    continue;
>>>>>> +
>>>>>> +            } else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
>>>>>> +                    /*
>>>>>> +                     * Report list of "SupportEncoding"
>>>>>> +                     *
>>>>>> +                     *      "SupportedEncoding": [
>>>>>> +                     *              "utf-16"
>>>>>> +                     *      ],
>>>>>> +                     *
>>>>>> +                     */
>>>>>> +
>>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
>>>>>> +                                        buf, hp_wmi_elements[type][i]);
>>>>>> +                    for (j = 0; j < size; j++) {
>>>>>> +                            status = get_string_from_buffer((u16
>>>>>> **)&obj->buffer.pointer, &str);
>>>>>> +                            if (ACPI_SUCCESS(status)) {
>>>>>> +                                    if (j == size - 1)
>>>>>> +                                            buf_size = snprintf(buf,
>>>>>> alloc_size,
>>>>>> +
>>>>>> "%s\t\t\"%s\"\n", buf, str);
>>>>>> +                                    else
>>>>>> +                                            buf_size = snprintf(buf,
>>>>>> alloc_size,
>>>>>> +
>>>>>> "%s\t\t\"%s\",\n", buf, str);
>>>>>> +                            }
>>>>>> +                            kfree(str);
>>>>>> +                            str = NULL;
>>>>>> +                    }
>>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>>>>>> +                    continue;
>>>>>> +            }
>>>>>> +
>>>>>> +            size = 0;
>>>>>> +            status = get_integer_from_buffer((int **)&obj-
>>>>>>> buffer.pointer, &integer);
>>>>>> +            if (ACPI_SUCCESS(status)) {
>>>>>> +                    /*
>>>>>> +                     * Report "PrerequisiteSize" and "Size" values
>>>>>> +                     *      ...
>>>>>> +                     *      "PrerequisiteSize": 1,
>>>>>> +                     *      ...
>>>>>> +                     *      "Size": 2,
>>>>>> +                     *      ...
>>>>>> +                     */
>>>>>> +                    if (i == 7)
>>>>>> +                            size = integer;
>>>>>> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
>>>>>> == 10)
>>>>>> +                            size = integer;
>>>>>> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
>>>>>> 9)
>>>>>> +                            size = integer;
>>>>>> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
>>>>>> 11)
>>>>>> +                            size = integer;
>>>>>> +
>>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
>>>>>> %d,\n", buf,
>>>>>> +                                        hp_wmi_elements[type][i],
>>>>>> integer);
>>>>>> +            }
>>>>>> +
>>>>>> +            if (size > 20)
>>>>>> +                    pr_warn("%s exceeded the maximum number of
>>>>>> elements supported or data may be malformed\n",
>>>>>> +                            hp_wmi_elements[type][i]);
>>>>>> +
>>>>>> +            if (ACPI_SUCCESS(status) && i == 7) {
>>>>>> +                    buf_size = snprintf(buf, alloc_size,
>>>>>> "%s\t\"Prerequisites\": [\n", buf);
>>>>>> +                    for (j = 0; j < size; j++) {
>>>>>> +                            status = get_string_from_buffer((u16
>>>>>> **)&obj->buffer.pointer, &str);
>>>>>> +                            if (ACPI_SUCCESS(status)) {
>>>>>> +                                    buf_size = snprintf(buf, alloc_size,
>>>>>> "%s\t\t\"%s\"", buf, str);
>>>>>> +
>>>>>> +                                    if (j == size - 1)
>>>>>> +                                            buf_size = snprintf(buf,
>>>>>> alloc_size, "%s\n", buf);
>>>>>> +                                    else
>>>>>> +                                            buf_size = snprintf(buf,
>>>>>> alloc_size, "%s,\n", buf);
>>>>>> +
>>>>>> +                            }
>>>>>> +                            kfree(str);
>>>>>> +                            str = NULL;
>>>>>> +                    }
>>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>>>>>> +            }
>>>>>> +    }
>>>>>> +
>>>>>> +    if (type == HPWMI_ENUMERATION_TYPE || type ==
>>>>>> HPWMI_ORDEREDLIST_TYPE) {
>>>>>> +            if (type == HPWMI_ENUMERATION_TYPE)
>>>>>> +                    buf_size = snprintf(buf, alloc_size,
>>>>>> "%s\t\"PossibleValues\": [\n", buf);
>>>>>> +            else
>>>>>> +                    buf_size = snprintf(buf, alloc_size,
>>>>>> "%s\t\"Elements\": [\n", buf);
>>>>>> +
>>>>>> +            for (i = 0; i < size; i++) {
>>>>>> +                    status = get_string_from_buffer((u16 **)&obj-
>>>>>>> buffer.pointer, &str);
>>>>>> +                    if (ACPI_SUCCESS(status)) {
>>>>>> +                            buf_size = snprintf(buf, alloc_size,
>>>>>> "%s\t\t\"%s\"", buf, str);
>>>>>> +
>>>>>> +                            if (i == size - 1)
>>>>>> +                                    buf_size = snprintf(buf, alloc_size,
>>>>>> "%s\n", buf);
>>>>>> +                            else
>>>>>> +                                    buf_size = snprintf(buf, alloc_size,
>>>>>> "%s,\n", buf);
>>>>>> +
>>>>>> +                    }
>>>>>> +                    kfree(str);
>>>>>> +                    str = NULL;
>>>>>> +            }
>>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
>>>>>> +    }
>>>>>> +
>>>>>> +    /*
>>>>>> +     * remove trailing comma
>>>>>> +     */
>>>>>> +    if (buf_size > 3)
>>>>>> +            buf[buf_size - 2] = ' ';
>>>>>> +
>>>>>> +    return snprintf(buf, alloc_size, "%s},\n", buf);
>>>>>> +}
>>>>>> +
>>>>>> +static int hp_bios_settings_free_buffer(void)
>>>>>> +{
>>>>>> +    mutex_lock(&buf_mutex);
>>>>>> +    kfree(hp_bios_settings_buffer);
>>>>>> +    settings_buffer_size = 0;
>>>>>> +    buf_alloc_size = 0;
>>>>>> +    mutex_unlock(&buf_mutex);
>>>>>> +
>>>>>> +    return 0;
>>>>>> +}
>>>>>> +
>>>>>> +static int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
>>>>>> +                                       int *alloc_size,
>>>>>> +                                       struct mutex *buf_mutex)
>>>>>> +{
>>>>>> +    int new_buffer_size;
>>>>>> +    char *new_buf = NULL;
>>>>>> +    int ret = 0;
>>>>>> +
>>>>>> +    if (*buf_size + PAGE_SIZE >= *alloc_size) {
>>>>>> +            new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
>>>>>> +
>>>>>> +            mutex_lock(buf_mutex);
>>>>>> +            new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
>>>>>> +            mutex_unlock(buf_mutex);
>>>>>> +            if (new_buf) {
>>>>>> +                    mutex_lock(buf_mutex);
>>>>>> +                    *buf = new_buf;
>>>>>> +                    *alloc_size = ksize(new_buf);
>>>>>> +                    mutex_unlock(buf_mutex);
>>>>>> +            } else {
>>>>>> +                    hp_bios_settings_free_buffer();
>>>>>> +                    ret = -ENOMEM;
>>>>>> +            }
>>>>>> +    }
>>>>>> +
>>>>>> +    return ret;
>>>>>> +}
>>>>>> +
>>>>>> +static int append_settings_to_buffer(char *guid, int type, char **buf,
>>>>>> +                                 int *buf_size, int *alloc_size,
>>>>>> +                                 struct mutex *buf_mutex)
>>>>>> +{
>>>>>> +    union acpi_object *obj = NULL;
>>>>>> +    int ret = 0;
>>>>>> +    int status = 0;
>>>>>> +    int instance = 0;
>>>>>> +
>>>>>> +    /*
>>>>>> +     * Query all the instances until to receive a AE_BAD_PARAMETER
>>>>>> +     */
>>>>>> +    do {
>>>>>> +            ret = hp_wmi_get_setting_object(guid, instance++, &obj);
>>>>>> +            if (ACPI_SUCCESS(ret) && obj != NULL) {
>>>>>> +                    status = 0;
>>>>>> +                    if (obj->type == ACPI_TYPE_PACKAGE) {
>>>>>> +                            mutex_lock(buf_mutex);
>>>>>> +                            status =
>>>>>> append_package_elements_to_buffer(obj,
>>>>>> +                                                    *buf, *alloc_size,
>>>>>> type);
>>>>>> +                            if (status > 0)
>>>>>> +                                    *buf_size = status;
>>>>>> +                            mutex_unlock(buf_mutex);
>>>>>> +
>>>>>> +                    } else if (obj->type == ACPI_TYPE_BUFFER) {
>>>>>> +                            mutex_lock(buf_mutex);
>>>>>> +                            status =
>>>>>> append_buffer_elements_to_buffer(obj,
>>>>>> +                                                    *buf, *alloc_size,
>>>>>> type);
>>>>>> +                            if (status > 0)
>>>>>> +                                    *buf_size = status;
>>>>>> +                            mutex_unlock(buf_mutex);
>>>>>> +
>>>>>> +                    } else
>>>>>> +                            pr_warn("The retrieved object type(%d) is
>>>>>> not supported yet\n",
>>>>>> +                                    obj->type);
>>>>>> +
>>>>>> +                    ret = hp_bios_settings_realloc_buffer(buf, buf_size,
>>>>>> alloc_size, buf_mutex);
>>>>>> +            }
>>>>>> +
>>>>>> +            kfree(obj);
>>>>>> +            obj = NULL;
>>>>>> +
>>>>>> +    } while (ACPI_SUCCESS(ret));
>>>>>> +
>>>>>> +    /*
>>>>>> +     * AE_BAD_PARAMETER means the loop ended by exhaustion
>>>>>> +     */
>>>>>> +    if (ret == AE_BAD_PARAMETER)
>>>>>> +            ret = 0;
>>>>>> +
>>>>>> +    return ret;
>>>>>> +}
>>>>>> +
>>>>>> +static int hp_bios_settings_fill_buffer(void)
>>>>>> +{
>>>>>> +    int status = 0;
>>>>>> +    int initial_buffer_size = 20 * PAGE_SIZE;
>>>>>> +
>>>>>> +    mutex_lock(&buf_mutex);
>>>>>> +    hp_bios_settings_buffer = kmalloc(initial_buffer_size,
>>> GFP_KERNEL);
>>>>>> +    mutex_unlock(&buf_mutex);
>>>>>> +    if (!hp_bios_settings_buffer)
>>>>>> +            return -ENOMEM;
>>>>>> +
>>>>>> +    mutex_lock(&buf_mutex);
>>>>>> +    buf_alloc_size = ksize(hp_bios_settings_buffer);
>>>>>> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
>>>>>> +                                    buf_alloc_size, "[\n");
>>>>>> +    mutex_unlock(&buf_mutex);
>>>>>> +
>>>>>> +    status = append_settings_to_buffer(HPWMI_STRING_GUID,
>>>>>> +            HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
>>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
>>>>>> +    if (ACPI_FAILURE(status))
>>>>>> +            pr_err("error 0x%x occurred retrieving string instances\n",
>>>>>> status);
>>>>>> +
>>>>>> +    status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
>>>>>> +            HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
>>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
>>>>>> +    if (ACPI_FAILURE(status))
>>>>>> +            pr_err("error 0x%x occurred retrieving integer instances\n",
>>>>>> status);
>>>>>> +
>>>>>> +    status =
>>> append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
>>>>>> +            HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
>>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
>>>>>> +    if (ACPI_FAILURE(status))
>>>>>> +            pr_err("error 0x%x occurred retrieving enumeration
>>>>>> instances\n", status);
>>>>>> +
>>>>>> +    status = append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
>>>>>> +            HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
>>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
>>>>>> +    if (ACPI_FAILURE(status))
>>>>>> +            pr_err("error 0x%x occurred retrieving ordered list
>>>>>> instances\n", status);
>>>>>> +
>>>>>> +    status = append_settings_to_buffer(HPWMI_PASSWORD_GUID,
>>>>>> +            HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
>>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
>>>>>> +    if (ACPI_FAILURE(status))
>>>>>> +            pr_err("error 0x%x occurred retrieving password list
>>>>>> instances\n", status);
>>>>>> +
>>>>>> +    mutex_lock(&buf_mutex);
>>>>>> +    /*
>>>>>> +     * remove trailing comma
>>>>>> +     */
>>>>>> +    if (settings_buffer_size >= 3) {
>>>>>> +            if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
>>>>>> +                    hp_bios_settings_buffer[settings_buffer_size - 2] = '
>>>>>> ';
>>>>>> +    }
>>>>>> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
>>>>>> +                                    buf_alloc_size, "%s]\n",
>>>>>> +                                    hp_bios_settings_buffer);
>>>>>> +    mutex_unlock(&buf_mutex);
>>>>>> +
>>>>>> +    return settings_buffer_size;
>>>>>> +}
>>>>>> +
>>>>>> +/*
>>>>>> + * sure_admin_settings_read - Return a formatted file with settings
>>>>>> + *                              and possible options read from BIOS
>>>>>> + *
>>>>>> + * @filp:  Pointer to file of settings read from BIOS
>>>>>> + * @kobj:  Pointer to a kernel object of things that show up as directory
>>> in
>>>>>> the sysfs filesystem.
>>>>>> + * @attr:  Pointer to list of read attributes
>>>>>> + * @buf:   Pointer to buffer
>>>>>> + * @off:   File current offset
>>>>>> + * @count: Buffer size
>>>>>> + *
>>>>>> + * Returns the count of unicode chars read if successful, otherwise
>>>>>> + *          -ENOMEM unable to allocate memory
>>>>>> + *          -EINVAL buffer not allocated or too small
>>>>>> + *
>>>>>> + */
>>>>>> +static ssize_t sure_admin_settings_read(struct file *filp, struct kobject
>>>>>> *kobj,
>>>>>> +                                    struct bin_attribute *attr, char *buf,
>>>>>> loff_t off, size_t count)
>>>>>> +{
>>>>>> +    ssize_t ret;
>>>>>> +
>>>>>> +    /* clear the buffer when offset is pointing to the last position */
>>>>>> +    if (off >= settings_buffer_size && settings_buffer_size > 0) {
>>>>>> +            hp_bios_settings_free_buffer();
>>>>>> +            return 0;
>>>>>> +    }
>>>>>> +
>>>>>> +    /* clear the buffer whenever the read starts from the first position
>>>>>> */
>>>>>> +    if (off == 0 && settings_buffer_size > 0)
>>>>>> +            hp_bios_settings_free_buffer();
>>>>>> +
>>>>>> +    if (settings_buffer_size == 0)
>>>>>> +            hp_bios_settings_fill_buffer();
>>>>>> +
>>>>>> +    mutex_lock(&buf_mutex);
>>>>>> +    ret = memory_read_from_buffer(buf, count, &off,
>>>>>> hp_bios_settings_buffer,
>>>>>> +                                  settings_buffer_size);
>>>>>> +    mutex_unlock(&buf_mutex);
>>>>>> +
>>>>>> +    return ret;
>>>>>> +}
>>>>>> +
>>>>>> +
>>>>>> +/*
>>>>>> + * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
>>>>>> + *
>>>>>> + * @p:   Unicode buffer address
>>>>>> + * @str: string to convert to unicode
>>>>>> + *
>>>>>> + * Returns a void pointer to the buffer containing unicode string
>>>>>> + */
>>>>>> +static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
>>>>>> +{
>>>>>> +    int len = strlen(str);
>>>>>> +
>>>>>> +    /*
>>>>>> +     * Add null character when reading an empty string
>>>>>> +     */
>>>>>> +    if (len == 0) {
>>>>>> +            *p++ = 2;
>>>>>> +            *p++ = (u8)0x00;
>>>>>> +            return p;
>>>>>> +    }
>>>>>> +    *p++ = len * 2;
>>>>>> +    utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
>>>>>> +    p += len;
>>>>>> +
>>>>>> +    return p;
>>>>>> +}
>>>>>> +
>>>>>> +/*
>>>>>> + * hp_wmi_set_bios_setting - Set setting's value in BIOS
>>>>>> + *
>>>>>> + * @input_buffer: Input buffer address
>>>>>> + * @input_size:   Input buffer size
>>>>>> + *
>>>>>> + * Returns: Count of unicode characters written to BIOS if successful,
>>>>>> otherwise
>>>>>> + *          -ENOMEM unable to allocate memory
>>>>>> + *          -EINVAL buffer not allocated or too small
>>>>>> + */
>>>>>> +static int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
>>>>>> +{
>>>>>> +    union acpi_object *obj;
>>>>>> +    struct acpi_buffer input = {input_size, input_buffer};
>>>>>> +    struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
>>>>>> +    int ret = 0;
>>>>>> +
>>>>>> +    ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID, 0, 1,
>>>>>> &input, &output);
>>>>>> +
>>>>>> +    obj = output.pointer;
>>>>>> +    if (!obj)
>>>>>> +            return -EINVAL;
>>>>>> +
>>>>>> +    if (obj->type != ACPI_TYPE_INTEGER)
>>>>>> +            ret = -EINVAL;
>>>>>> +
>>>>>> +    ret = obj->integer.value;
>>>>>> +    kfree(obj);
>>>>>> +    return ret;
>>>>>> +}
>>>>>> +
>>>>>> +/* Sure Admin Functions */
>>>>>> +
>>>>>> +#define UTF_PREFIX                  ((unsigned char *)"<utf-16/>")
>>>>>> +#define BEAM_PREFIX                 ((unsigned char
>>>>>> *)"<BEAM/>")
>>>>>> +
>>>>>> +/*
>>>>>> + * sure_admin_settings_write - Write the contents of a formatted file
>>>>>> + *                               with settings and performs the logic
>>>>>> + *                               to change any settings in BIOS.
>>>>>> + *
>>>>>> + * @filp:  Pointer to file of settings to be written to BIOS
>>>>>> + * @kobj:  Pointer to a kernel object of things that show up as directory
>>> in
>>>>>> the sysfs filesystem.
>>>>>> + * @attr:  Pointer to list of attributes for the write operation
>>>>>> + * @buf:   Pointer to buffer
>>>>>> + * @off:   File current offset
>>>>>> + * @count: Buffer size
>>>>>> + *
>>>>>> + *
>>>>>> + * Returns the count of unicode characters written to BIOS if
>>> successful,
>>>>>> otherwise
>>>>>> + *          -ENOMEM unable to allocate memory
>>>>>> + *          -EINVAL buffer not allocated or too small
>>>>>> + *
>>>>>> + */
>>>>>> +static ssize_t sure_admin_settings_write(struct file *filp, struct kobject
>>>>>> *kobj,
>>>>>> +                    struct bin_attribute *attr, char *buf, loff_t off, size_t
>>>>>> count)
>>>>>> +{
>>>>>> +    int status = 0;
>>>>>> +    char *part = NULL;
>>>>>> +    int part_len = 0;
>>>>>> +    unsigned short *buffer = NULL;
>>>>>> +    unsigned short *tmpstr = NULL;
>>>>>> +    int buffer_size = (count + strlen(UTF_PREFIX)) * sizeof(unsigned
>>>>>> short);
>>>>>> +
>>>>>> +    buffer = kmalloc(buffer_size, GFP_KERNEL);
>>>>>> +    if (!buffer)
>>>>>> +            return -ENOMEM;
>>>>>> +
>>>>>> +    tmpstr = buffer;
>>>>>> +    part = strsep(&buf, ",");
>>>>>> +    if (!part) {
>>>>>> +            status = -EINVAL;
>>>>>> +            goto out_free;
>>>>>> +    }
>>>>>> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
>>>>>> +    part = strsep(&buf, ",");
>>>>>> +    if (!part) {
>>>>>> +            status = -EINVAL;
>>>>>> +            goto out_free;
>>>>>> +    }
>>>>>> +
>>>>>> +    /* Add extra buffer space when encountering an empty string */
>>>>>> +    if (!strlen(part))
>>>>>> +            buffer_size += sizeof(unsigned short);
>>>>>> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
>>>>>> +    part = strsep(&buf, ",");
>>>>>> +    if (!part) {
>>>>>> +            status = -EINVAL;
>>>>>> +            goto out_free;
>>>>>> +    }
>>>>>> +    part_len = strlen(part) - 1;
>>>>>> +    part[part_len] = '\0';
>>>>>> +
>>>>>> +    if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
>>>>>> +           /*
>>>>>> +            * BEAM_PREFIX is append to buffer when a signature
>>>>>> +            * is provided and Sure Admin is enabled in BIOS
>>>>>> +            */
>>>>>> +            // BEAM_PREFIX found, convert part to unicode
>>>>>> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
>>>>>> +            // decrease buffer size allocated initially for UTF_PREFIX
>>>>>> +            buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
>>>>>> +    } else {
>>>>>> +            /*
>>>>>> +             * UTF-16 prefix is append to the * buffer when a BIOS
>>>>>> +             * admin password is configured in BIOS
>>>>>> +             */
>>>>>> +
>>>>>> +            // append UTF_PREFIX to part and then convert it to unicode
>>>>>> +            part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
>>>>>> +            if (!part)
>>>>>> +                    goto out_free;
>>>>>> +
>>>>>> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
>>>>>> +            kfree(part);
>>>>>> +    }
>>>>>> +
>>>>>> +    part = strsep(&buf, ",");
>>>>>> +    if (part) {
>>>>>> +            status = -EINVAL;
>>>>>> +            goto out_free;
>>>>>> +    }
>>>>>> +    status = hp_wmi_set_bios_setting(buffer, buffer_size);
>>>>>> +    if (ACPI_FAILURE(status))
>>>>>> +            status = -EINVAL;
>>>>>> +
>>>>>> +out_free:
>>>>>> +    kfree(buffer);
>>>>>> +    if (ACPI_SUCCESS(status))
>>>>>> +            return count;
>>>>>> +    return status;
>>>>>> +}
>>>>>> +
>>>>>> +HPWMI_BINATTR_RW(sure_admin, settings, 0);
>>>>>> +
>>>>>> +static struct bin_attribute *sure_admin_binattrs[] = {
>>>>>> +    &sure_admin_settings,
>>>>>> +    NULL,
>>>>>> +};
>>>>>> +
>>>>>> +static const struct attribute_group sure_admin_group = {
>>>>>> +    .name = "sure_admin",
>>>>>> +    .bin_attrs = sure_admin_binattrs,
>>>>>> +};
>>>>>> +
>>>>>>  static DEVICE_ATTR_RO(display);
>>>>>>  static DEVICE_ATTR_RO(hddtemp);
>>>>>>  static DEVICE_ATTR_RW(als);
>>>>>> @@ -1050,6 +2026,7 @@ static const struct attribute_group
>>>>>> *hp_wmi_groups[] = {
>>>>>>      &hp_wmi_group,
>>>>>>      &spm_group,
>>>>>>      &sure_start_group,
>>>>>> +    &sure_admin_group,
>>>>>>      NULL,
>>>>>>  };
>>>>>>
>>>>>> --
>>>>>> 2.25.1
>>>>
>

Jorge Lopez April 8, 2022, 2:46 p.m. UTC | #9

On Fri, Apr 8, 2022 at 4:21 AM Hans de Goede <[e-mail]> wrote:
>
> Hi Jorge,
>
> On 4/7/22 15:44, Jorge Lopez wrote:
> > Hans, Mario,
> >
> > The code links make references to code that implements the new
> > interfaces but there’s
> > still code in the kernel that uses the old ones.
>
> I'm not sure what you mean with "uses the old ones" there never
> has been any kernel drivers for changing BIOS settings before
> the dell and lenovo drivers were merged.

"uses the old ones" statement means that there are drivers on the tree
that change BIOS settings without having to convert to the new
standards.  hp-wmi remained unsupported for many years so I can
understand why the security features need to use the standardized API.

>
> Sure there are generic mechanisms like chardev-s and ioctls which
> are used for a whole bunch of things. But AFAIK there never was
> an API specifically for changing BIOS settings before.
>
> > I do agree we should
> > be forward looking
> > and want to be good participants in the kernel development, but can’t
> > let our immediate
> > business needs be impacted with opportunities to enhance the driver to
> > take advantage
> > of the latest kernel features.
> >
> > Rewriting those security features will impact customer business
> > datelines requiring
> > HP to provide private releases as the kernel version changes.   The
> > requested changes
> > will impact products in the market and HP ability to help customers to
> > migrate to Linux
> > from Windows products.
>
> This sounds like you are saying that you are already shipping
> a version of the driver with the non-standard API to customers.
> Shipping code to customers before even proposing it upstream is
> HP own choice and the results of that as such are HP's
> responsibility.
>
The products shipped to customers are Windows products and customers
are accustomed to how the data is reported and set.  The goal for the
new security features in Linux is to help those customers migrate to
Linux with little or no change to their scripts/tools.

> You cannot just say we are already shipping this so we need
> the upstream kernel to support this non standard API, that is
> not how upstream kernel development works.
>
> I realize that HP is new to working directly with the upstream kernel
> community and I realize that being told that the API which you are
> already using cannot be used for upstreaming your driver is not what
> you want to hear.
>
> But that does not change that I cannot accept a driver which does not
> implement the standard API which the upstream kernel community has
> agreed upon for this functionality.
>
> Or as Mario very elegantly put it:
>
> 'Keep in mind that from an upstream kernel perspective this driver is "new".
> There is no requirements from the upstream perspective to
> keep your old interfaces in place from when it was out of tree.'
>
> > It is because of the immediate business needs, avoiding impacting our
> > customers/products,
> > and rewriting  enhancements to the driver that I need to propose an
> > interim solution.
> >
> > My proposal is to introduce a read/write value accessible in the user
> > space to control how
> > the driver reports and handles BIOS settings and values.  The new
> > configuration features
> > will be gradually disabled  as they are converted to use the standardized API.
> > It is like the configuration flag used to overcome the tablet detection problem
> > introduced in the past.   The changes solely affect the HP WMI driver.
> > This option will help us
> > move forward for this release and give us time to make the necessary
> > changes to both
> > the driver and support applications.
> >
> > Please let me know if this is a viable interim solution.
>
> First of all to be very clear, any code going upstream must support
> the standard API:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-class-firmware-attributes
>
> from day one. I'm not really enthusiastic about the concept of also
> supporting the API which you have been using out of tree so far, but
> I guess that Mario's suggestion to offer a Kconfig option which
> when enabled offers this API under debugfs might be an acceptible
> compromise. I would need to see the actual code for that though to
> see if this is acceptable.
>
> And there would need to be a clear cut-of date document after which
> the code to support the old API will be removed.
>
> > If it is not possible, I need to ask where the actual written
> > requirement is found so I can
> > include them in the business justification for changes and release
> > delays to management.
>
> I'm not sure if this is written down somewhere, but certainly
> you will agree that if you were submitting a driver for a soundcard
> that that should use the existing ALSA userspace API for sound so
> that it would just work with the existing userspace sound support.
>
> This is the same. If an existing standardized userspace API exists
> for a certain functionality then that userspace API _must_ be used,
> AFAIK this is not explictly written down anywhere because it is just
> very much common sense.

I completely agree with your comments and request for the driver to
implement the standardized API.  hp-wmi remained unsupported for many
years so I can understand why the security features need to use the
standardized API.  I am having conversations with other teams on how
to move forward with the standard API and how the data is handled and
reported.   We will submit a new set of patches utilizing the new
standard at a later time.   Would it be accurate to state that any
extensions to the standardized API model are acceptable, Correct?

Regards,

Jorge
>
> Regards,
>
> Hans
>
>
>
>
>
>
> > On Tue, Apr 5, 2022 at 12:13 PM Limonciello, Mario
> > <[e-mail]> wrote:
> >>
> >> [Public]
> >>
> >>
> >>
> >>> -----Original Message-----
> >>> From: Jorge Lopez <[e-mail]>
> >>> Sent: Tuesday, April 5, 2022 11:52
> >>> To: Hans de Goede <[e-mail]>
> >>> Cc: Limonciello, Mario <[e-mail]>; platform-driver-
> >>> [e-mail]
> >>> Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
> >>>
> >>> Hi Hans,
> >>>
> >>> On Tue, Apr 5, 2022 at 6:54 AM Hans de Goede <[e-mail]>
> >>> wrote:
> >>>>
> >>>> Hi,
> >>>>
> >>>> On 4/4/22 23:59, Limonciello, Mario wrote:
> >>>>> [Public]
> >>>>>
> >>>>>
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: Jorge Lopez <[e-mail]>
> >>>>>> Sent: Monday, April 4, 2022 15:36
> >>>>>> To: [e-mail]
> >>>>>> Subject: [PATCH v1 5/6] Sure Admin Security Feature
> >>>>>>
> >>>>>> HP Commercial PC's have several BIOS settings that control its
> >>>>>> behaviour and capabilities, many of which are related to security.  To
> >>>>>> prevent unauthorized changes to these settings, the system can be
> >>>>>> configured to use a Sure Admin cryptographic signature-based
> >>>>>> authorization string that the BIOS will use to verify authorization to
> >>>>>> modify the setting. Behind the scenes, Sure Admin uses Secure
> >>> Platform
> >>>>>> Management (SPM) and WMI
> >>>>>>
> >>>>>> 'settings' is a file associated with Sure Admin. BIOS settings can be
> >>>>>> read or written through the Sure Admin settings file in sysfs
> >>>>>>
> >>>>>>      /sys/devices/platform/hp-wmi/sure_admin/settings
> >>>>>>
> >>>>>> Expected data format to update BIOS setting
> >>>>>>
> >>>>>>      [BIOS setting],[new value],[auth token]
> >>>>>>
> >>>>>> Sample settings reported data
> >>>>>>
> >>>>>>      {
> >>>>>>              "Class": "HPBIOS_BIOSEnumeration",
> >>>>>>              "Name": "USB Storage Boot",
> >>>>>>              "Path": "\\Advanced\\Boot Options",
> >>>>>>              "IsReadOnly": 0,
> >>>>>>              ...
> >>>>>>              "Value": "Enable",
> >>>>>>              "Size": 2,
> >>>>>>              "PossibleValues": [
> >>>>>>                      "Disable",
> >>>>>>                      "Enable"
> >>>>>>              ]
> >>>>>>      }
> >>>>>>
> >>>>>
> >>>>> This sounds like it has re-invented /sys/class/firmware-attributes.
> >>>>>
> >>>>> Shouldn't you adopt that API?
> >>>>
> >>>> I fully agree. Jorge as I already indicated in our off-list
> >>>> conversation when you initially started working on this
> >>>> feature, we already have a standardized API for querying/changing
> >>>> BIOS settings from within Linux:
> >>>>
> >>>
> >>> I agree that changing the BIOS settings from within Linux could
> >>> utilize the new methodology,  I will need to look closely at the
> >>> requirements before I can proceed to make the changes.
> >>> Keep in mind authentication of the values is done by BIOS.  No Linux
> >>> process validates any data name, value, or auth token; only BIOS.  All
> >>> data written to the sysfs file is not validated, it is just forward to
> >>> BIOS.  See spm_kek_store and spm_sk_store functions.
> >>
> >> That's fine, and it's a safer design to have BIOS validate it.
> >>
> >>> One point I must make clear when updating BIOS settings.  any  NOT
> >>> read-only BIOS settings can be changed by the application at any time.
> >>>    This list of settings changes from one system to another.
> >>
> >> Right.
> >>
> >>>
> >>> I am in disagreement with reading the settings.  hp-wmi does not read
> >>> one value at a time. It reads all values exposed by BIOS.  See
> >>> attached sample output.
> >>
> >> The settings can all be read at initialization time for the driver and cached
> >> then.
> >>
> >>> The method for how all BIOS settings are reported needs to match the
> >>> method how Windows products do it.  It is a requirement to start
> >>> migrating customers from Windows to Linux while minimizing how BIOS
> >>> data is reported.
> >>
> >> Because we have a standardized API in Linux for this, I think it's best to abstract
> >> this behind a userspace application/script.  If they expect to see it in the format you
> >> showed, the userspace application can take the data from Linux and package it that
> >> way.
> >>
> >> You'll have richer libraries and languages and tools to work from when doing this too.
> >> It should make it a lot less painful.
> >>
> >>>
> >>> I will investigate the new API and bring it to the team's attention.
> >>>
> >>>>
> >>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> >>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> >>> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> >>> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
> >>> f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
> >>> 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> >>> C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
> >>> &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
> >>> D&amp;reserved=0
> >>>>
> >>>> and any new code (such as this patch) which implements BIOS
> >>>> setting changing MUST follow this standardized API (extending
> >>>> it where necessary).
> >>>>
> >>>> I'm sorry but this patch is not acceptable in its current form,
> >>>> it needs to be *completely rewritten* to implement:
> >>>>
> >>>>
> >>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> >>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> >>> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> >>> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
> >>> f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
> >>> 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> >>> C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
> >>> &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
> >>> D&amp;reserved=0
> >>>>
> >>>> See:
> >>>>
> >>>>
> >>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> >>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> >>> 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fdell%2Fdell-wmi-
> >>> sysman&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8f
> >>> ea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> >>> 7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> >>> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> >>> mp;sdata=z5jmH7ECYBeLcndQ2vfHaUuyE04Eaf1Lymh6BjnyJ%2Fk%3D&amp;r
> >>> eserved=0
> >>>>
> >>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> >>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> >>> 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fthink-
> >>> lmi.c&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea
> >>> 104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C
> >>> 0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLj
> >>> AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;
> >>> sdata=5n6w9LEB2iWpj1cOQP6Ngz94AqP1Bu4vu8T0EdN%2FThU%3D&amp;re
> >>> served=0
> >>>>
> >>>> for example code / for 2 drivers from other vendors already
> >>>> implementing this.
> >>>>
> >>>> The same applies to the:
> >>>>
> >>>> "[PATCH v1 3/6] Secure Platform Management Security Feature"
> >>>>
> >>>> this needs to be implemented as
> >>>> a /sys/class/firmware-attributes/*/authentication/
> >>>> authentication method, see for example these Lenovo specific
> >>>> addition to the /sys/class/firmware-attributes/*/authentication/
> >>>> userspace API for similar functionality on Lenovo Think* devices:
> >>>>
> >>>>
> >>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> >>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> >>> 2Fcommit%2F%3Fid%3D06384573a3e8335ac6797577e545c33dbf91b490&amp;
> >>> data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea1040342827
> >>> 08da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C63784
> >>> 7743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLC
> >>> JQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=eldS
> >>> 4H3Z%2BAyL%2FG%2FO9W9rDGC37yh5sGgtUhpKdUAoSmA%3D&amp;reser
> >>> ved=0
> >>>>
> >>>> I'll merge patches 1-2 sometime this week since those are
> >>>> fine and it will be good to have those "out of the way",
> >>>> but the rest of the series will need to be rewritten
> >>>> taken the above comments into account.
> >>>
> >>> v1-0003-Sure-Start-Security-Feature.patch  reports the number of audit
> >>> logs available and reports them when read.    it does not read/write
> >>> BIOS settings hence it does not fall within the same category as
> >>> patches v1-0002-Secure-Platform-Management-Security-Feature.patch and
> >>> v1-0004-Sure-Admin-Security-Feature.patch
> >>> Do you agree?
> >>>
> >>>>
> >>>> Regards,
> >>>>
> >>>> Hans
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>>
> >>>>>> This feature requires "Update hp_wmi_group to simplify feature
> >>>>>> addition" patch.
> >>>>>>
> >>>>>> All changes were validated on a HP ZBook Workstation,
> >>>>>> HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
> >>>>>>
> >>>>>> Signed-off-by: Jorge Lopez <[e-mail]>
> >>>>>>
> >>>>>> ---
> >>>>>> Based on the latest platform-drivers-x86.git/for-next
> >>>>>> ---
> >>>>>>  drivers/platform/x86/hp-wmi.c | 977
> >>>>>> ++++++++++++++++++++++++++++++++++
> >>>>>>  1 file changed, 977 insertions(+)
> >>>>>>
> >>>>>> diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-
> >>> wmi.c
> >>>>>> index 918e3eaf1b67..b72ca18b77a6 100644
> >>>>>> --- a/drivers/platform/x86/hp-wmi.c
> >>>>>> +++ b/drivers/platform/x86/hp-wmi.c
> >>>>>> @@ -27,6 +27,7 @@
> >>>>>>  #include <linux/rfkill.h>
> >>>>>>  #include <linux/string.h>
> >>>>>>  #include <linux/dmi.h>
> >>>>>> +#include <linux/nls.h>
> >>>>>>
> >>>>>>  MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
> >>>>>>  MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
> >>>>>> @@ -37,8 +38,16 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-
> >>>>>> 3D44E2C707E4");
> >>>>>>
> >>>>>>  #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-
> >>> ACCDC67EF61C"
> >>>>>>  #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-
> >>> 3D44E2C707E4"
> >>>>>> +
> >>>>>>  #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
> >>>>>>
> >>>>>> +#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-
> >>> 6A1B8106F83C"
> >>>>>> +#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-
> >>>>>> E293ADB9BF05"
> >>>>>> +#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-
> >>>>>> 4A3C09E75133"
> >>>>>> +#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-A0E0-
> >>>>>> 7045CB4DA745"
> >>>>>> +#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-
> >>>>>> 015176049E2D"
> >>>>>> +#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-951D-
> >>>>>> C7CB9B4B8D5E"
> >>>>>> +
> >>>>>>  /* DMI board names of devices that should use the omen specific path
> >>> for
> >>>>>>   * thermal profiles.
> >>>>>>   * This was obtained by taking a look in the windows omen command
> >>> center
> >>>>>> @@ -1025,6 +1034,973 @@ static const struct attribute_group
> >>>>>> sure_start_group = {
> >>>>>>      .attrs = sure_start_attrs,
> >>>>>>  };
> >>>>>>
> >>>>>> +
> >>>>>> +static int convert_hexstr_to_str(char **hex, int input_len, char **str,
> >>> int
> >>>>>> *len)
> >>>>>> +{
> >>>>>> +    int ret = 0;
> >>>>>> +    int new_len = 0;
> >>>>>> +    char tmp[] = "0x00";
> >>>>>> +    char *input = *hex;
> >>>>>> +    char *new_str = NULL;
> >>>>>> +    int  ch;
> >>>>>> +    int i;
> >>>>>> +
> >>>>>> +    if (input_len <= 0 || hex == NULL || str == NULL || len == NULL)
> >>>>>> +            return -EINVAL;
> >>>>>> +
> >>>>>> +    *len = 0;
> >>>>>> +    *str = NULL;
> >>>>>> +
> >>>>>> +    new_str = kmalloc(input_len, GFP_KERNEL);
> >>>>>> +    if (!new_str)
> >>>>>> +            return -ENOMEM;
> >>>>>> +
> >>>>>> +    for (i = 0; i < input_len; i += 5) {
> >>>>>> +            strncpy(tmp, input + i, strlen(tmp));
> >>>>>> +            ret = kstrtoint(tmp, 16, &ch);
> >>>>>> +            if (ret) {
> >>>>>> +                    new_len = 0;
> >>>>>> +                    break;
> >>>>>> +            }
> >>>>>> +
> >>>>>> +            if (ch == '\\')
> >>>>>> +                    new_str[new_len++] = '\\';
> >>>>>> +
> >>>>>> +            new_str[new_len++] = ch;
> >>>>>> +            if (ch == '\0')
> >>>>>> +                    break;
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    if (new_len) {
> >>>>>> +            new_str[new_len] = '\0';
> >>>>>> +            *str = krealloc(new_str, (new_len + 1) * sizeof(char),
> >>>>>> GFP_KERNEL);
> >>>>>> +            if (*str)
> >>>>>> +                    *len = new_len;
> >>>>>> +            else
> >>>>>> +                    ret = -ENOMEM;
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    if (ret)
> >>>>>> +            kfree(new_str);
> >>>>>> +    return ret;
> >>>>>> +}
> >>>>>> +
> >>>>>> +/*
> >>>>>> + * hp_wmi_get_setting_object() - Get an ACPI object by GUID and
> >>> instance
> >>>>>> + *
> >>>>>> + * @guid:   GUID associated with the ACPI list of managed objects
> >>>>>> + * @instance:       Instance index to query on the ACPI list
> >>>>>> + * @obj:    The output ACPI object of type ACPI_TYPE_PACKAGE
> >>>>>> + *          or ACPI_TYPE_BUFFER (freed by the callee)
> >>>>>> + *
> >>>>>> + * Returns  zero on success.  Otherwise,an error inherited from
> >>>>>> + *          wmi_query_block(). It returns a obj by parameter if
> >>>>>> + *          the query returned object of type buffer or package,
> >>>>>> + *          otherwise, a null obj is returned.
> >>>>>> + *
> >>>>>> + * Note: obj should be freed by the callee once it is finished working
> >>> with it
> >>>>>> + */
> >>>>>> +static int hp_wmi_get_setting_object(char *guid, int instance,
> >>>>>> +                            union acpi_object **obj)
> >>>>>> +{
> >>>>>> +    struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER, NULL
> >>>>>> };
> >>>>>> +    union acpi_object *tmp = NULL;
> >>>>>> +    int ret;
> >>>>>> +
> >>>>>> +    ret = wmi_query_block(guid, instance, &output);
> >>>>>> +    if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
> >>>>>> +            tmp = output.pointer;
> >>>>>> +            if (tmp->type == ACPI_TYPE_BUFFER || tmp->type ==
> >>>>>> ACPI_TYPE_PACKAGE)
> >>>>>> +                    *obj = output.pointer;
> >>>>>> +            else {
> >>>>>> +                    kfree(tmp);
> >>>>>> +                    *obj = NULL;
> >>>>>> +            }
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    return ret;
> >>>>>> +}
> >>>>>> +
> >>>>>> +
> >>>>>> +static int get_string_from_buffer(u16 **buffer, char **str)
> >>>>>> +{
> >>>>>> +    u16 *ptr = *buffer;
> >>>>>> +    u16 ptrlen;
> >>>>>> +
> >>>>>> +    u16 size;
> >>>>>> +    int i;
> >>>>>> +    char *output = NULL;
> >>>>>> +    int escape = 0;
> >>>>>> +
> >>>>>> +    ptrlen = *(ptr++);
> >>>>>> +    size = ptrlen / 2;
> >>>>>> +
> >>>>>> +    if (size == 0)
> >>>>>> +            goto cleanup_exit;
> >>>>>> +
> >>>>>> +    for (i = 0; i < size; i++)
> >>>>>> +            if (ptr[i] == '\\')
> >>>>>> +                    escape++;
> >>>>>> +
> >>>>>> +    size += escape;
> >>>>>> +    *str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
> >>>>>> +    if (!*str)
> >>>>>> +            return -ENOMEM;
> >>>>>> +
> >>>>>> +    output = *str;
> >>>>>> +
> >>>>>> +    /*
> >>>>>> +     * convert from UTF-16 unicode to ASCII
> >>>>>> +     */
> >>>>>> +    utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output, size);
> >>>>>> +
> >>>>>> +    if (escape == 0) {
> >>>>>> +            ptr += (ptrlen / 2);
> >>>>>> +            goto cleanup_exit;
> >>>>>> +    }
> >>>>>> +    /*
> >>>>>> +     * Convert escape characters only when found
> >>>>>> +     */
> >>>>>> +    for (i = 0; i < size; i++) {
> >>>>>> +            if (*ptr == '\\')
> >>>>>> +                    output[i++] = '\\';
> >>>>>> +            output[i] = *ptr;
> >>>>>> +            ptr++;
> >>>>>> +    }
> >>>>>> +
> >>>>>> +cleanup_exit:
> >>>>>> +    *buffer = ptr;
> >>>>>> +    return 0;
> >>>>>> +}
> >>>>>> +
> >>>>>> +static int get_integer_from_buffer(int **buffer, int *integer)
> >>>>>> +{
> >>>>>> +    int *ptr = PTR_ALIGN(*buffer, 4);
> >>>>>> +    *integer = *(ptr++);
> >>>>>> +    *buffer = ptr;
> >>>>>> +    return 0;
> >>>>>> +}
> >>>>>> +
> >>>>>> +
> >>>>>> +// Sure Admin functions
> >>>>>> +enum hp_wmi_data_type {
> >>>>>> +    HPWMI_STRING_TYPE,
> >>>>>> +    HPWMI_INTEGER_TYPE,
> >>>>>> +    HPWMI_ENUMERATION_TYPE,
> >>>>>> +    HPWMI_ORDEREDLIST_TYPE,
> >>>>>> +    HPWMI_PASSWORD_TYPE,
> >>>>>> +};
> >>>>>> +
> >>>>>> +#define HP_WMI_COMMON_ELEMENTS      \
> >>>>>> +    "Name", \
> >>>>>> +    "Value",        \
> >>>>>> +    "Path", \
> >>>>>> +    "IsReadOnly",   \
> >>>>>> +    "DisplayInUI",  \
> >>>>>> +    "RequiresPhysicalPresence",     \
> >>>>>> +    "Sequence",     \
> >>>>>> +    "PrerequisiteSize",     \
> >>>>>> +    "SecurityLevel"
> >>>>>> +
> >>>>>> +const char *hp_wmi_string_elements[] = {
> >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> >>>>>> +    "MinLength",
> >>>>>> +    "MaxLength"
> >>>>>> +};
> >>>>>> +
> >>>>>> +const char *hp_wmi_integer_elements[] = {
> >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> >>>>>> +    "LowerBound",
> >>>>>> +    "UpperBound",
> >>>>>> +    "IntValue"
> >>>>>> +};
> >>>>>> +
> >>>>>> +const char *hp_wmi_enumeration_elements[] = {
> >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> >>>>>> +    "CurrentValue",
> >>>>>> +    "Size"
> >>>>>> +};
> >>>>>> +
> >>>>>> +const char *hp_wmi_orderedlist_elements[] = {
> >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> >>>>>> +    "Size"
> >>>>>> +};
> >>>>>> +
> >>>>>> +const char *hp_wmi_password_elements[] = {
> >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> >>>>>> +    "MinLength",
> >>>>>> +    "MaxLength",
> >>>>>> +    "Size",
> >>>>>> +    "SupportedEncoding",
> >>>>>> +    "IsSet"
> >>>>>> +};
> >>>>>> +
> >>>>>> +const char **hp_wmi_elements[] = {
> >>>>>> +    hp_wmi_string_elements,
> >>>>>> +    hp_wmi_integer_elements,
> >>>>>> +    hp_wmi_enumeration_elements,
> >>>>>> +    hp_wmi_orderedlist_elements,
> >>>>>> +    hp_wmi_password_elements
> >>>>>> +};
> >>>>>> +
> >>>>>> +const int hp_wmi_elements_count[] = {
> >>>>>> +    ARRAY_SIZE(hp_wmi_string_elements),
> >>>>>> +    ARRAY_SIZE(hp_wmi_integer_elements),
> >>>>>> +    ARRAY_SIZE(hp_wmi_enumeration_elements),
> >>>>>> +    ARRAY_SIZE(hp_wmi_orderedlist_elements),
> >>>>>> +    ARRAY_SIZE(hp_wmi_password_elements)
> >>>>>> +};
> >>>>>> +
> >>>>>> +const char *hp_wmi_classes[] = {
> >>>>>> +    "HPBIOS_BIOSString",
> >>>>>> +    "HPBIOS_BIOSInteger",
> >>>>>> +    "HPBIOS_BIOSEnumeration",
> >>>>>> +    "HPBIOS_BIOSOrderedList",
> >>>>>> +    "HPBIOS_BIOSPassword"
> >>>>>> +};
> >>>>>> +
> >>>>>> +static DEFINE_MUTEX(buf_mutex);
> >>>>>> +static int settings_buffer_size;
> >>>>>> +static int buf_alloc_size;
> >>>>>> +static char *hp_bios_settings_buffer;
> >>>>>> +
> >>>>>> +
> >>>>>> +static int append_package_elements_to_buffer(union acpi_object
> >>> *obj,
> >>>>>> +                                         char *buf, int alloc_size, enum
> >>>>>> hp_wmi_data_type type)
> >>>>>> +{
> >>>>>> +    int i;
> >>>>>> +    union acpi_object *pobj = NULL;
> >>>>>> +    char *value = NULL;
> >>>>>> +    int value_len;
> >>>>>> +    char *tmpstr = NULL;
> >>>>>> +    char *part_tmp = NULL;
> >>>>>> +    int tmp_len = 0;
> >>>>>> +    char *part = NULL;
> >>>>>> +    int status = 0;
> >>>>>> +    int size = 0;
> >>>>>> +    int buf_size;
> >>>>>> +
> >>>>>> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> >>>>>> +            return -EINVAL;
> >>>>>> +
> >>>>>> +    if (obj->type != ACPI_TYPE_PACKAGE)
> >>>>>> +            return -EINVAL;
> >>>>>> +
> >>>>>> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> >>>>>> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> >>>>>> hp_wmi_classes[type]);
> >>>>>> +
> >>>>>> +    for (i = 0; i < 3; i++) {
> >>>>>> +            pobj = &(obj->package.elements[i]);
> >>>>>> +            if (pobj->type == ACPI_TYPE_STRING) {
> >>>>>> +                    status = convert_hexstr_to_str(&pobj-
> >>>>>>> string.pointer,
> >>>>>> +                                                   pobj->string.length,
> >>>>>> &value, &value_len);
> >>>>>> +                    if (ACPI_FAILURE(status))
> >>>>>> +                            continue;
> >>>>>> +                    /*
> >>>>>> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> >>>>>> since
> >>>>>> +                     * 'CurrentValue' is reported.
> >>>>>> +                     */
> >>>>>> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> >>>>>> +                                                "%s\t\"%s\": \"%s\",\n",
> >>>>>> +                                                buf,
> >>>>>> +
> >>>>>> hp_wmi_elements[type][i], value);
> >>>>>> +
> >>>>>> +            }
> >>>>>> +            kfree(value);
> >>>>>> +            value = NULL;
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> >>>>>> +            pobj = &(obj->package.elements[i]);
> >>>>>> +
> >>>>>> +            if (type == HPWMI_ENUMERATION_TYPE &&
> >>>>>> +                i == 9 &&
> >>>>>> +                pobj->type == ACPI_TYPE_STRING) {
> >>>>>> +                    /*
> >>>>>> +                     * Report "CurrentValue" as "Value"
> >>>>>> +                     */
> >>>>>> +                    status = convert_hexstr_to_str(&pobj-
> >>>>>>> string.pointer,
> >>>>>> +                                                   pobj->string.length,
> >>>>>> +                                                   &value, &value_len);
> >>>>>> +                    if (ACPI_FAILURE(status))
> >>>>>> +                            continue;
> >>>>>> +
> >>>>>> +                    buf_size = snprintf(buf, alloc_size,
> >>>>>> +                                        "%s\t\"Value\": \"%s\",\n",
> >>>>>> +                                        buf, value);
> >>>>>> +                    kfree(value);
> >>>>>> +                    value = NULL;
> >>>>>> +
> >>>>>> +            } else if (type == HPWMI_PASSWORD_TYPE &&
> >>>>>> +                       i == 12 &&
> >>>>>> +                       pobj->type == ACPI_TYPE_STRING) {
> >>>>>> +                    /*
> >>>>>> +                     * Report list of "SupportEncoding"
> >>>>>> +                     *
> >>>>>> +                     *      "SupportedEncoding": [
> >>>>>> +                     *              "utf-16"
> >>>>>> +                     *      ],
> >>>>>> +                     *
> >>>>>> +                     */
> >>>>>> +
> >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> >>>>>> +                                        buf, hp_wmi_elements[type][i]);
> >>>>>> +                    while (size--) {
> >>>>>> +                            pobj = &(obj->package.elements[i]);
> >>>>>> +                            status = convert_hexstr_to_str(&pobj-
> >>>>>>> string.pointer,
> >>>>>> +                                                           pobj-
> >>>>>>> string.length,
> >>>>>> +                                                           &value,
> >>>>>> &value_len);
> >>>>>> +                            if (ACPI_FAILURE(status))
> >>>>>> +                                    continue;
> >>>>>> +
> >>>>>> +                            if (size) {
> >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> >>>>>> +                                                        "%s\t\t\"%s\",\n",
> >>>>>> buf, value);
> >>>>>> +                                    i++;
> >>>>>> +                            } else
> >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> >>>>>> +                                                        "%s\t\t\"%s\"\n",
> >>>>>> buf, value);
> >>>>>> +
> >>>>>> +                            kfree(value);
> >>>>>> +                            value = NULL;
> >>>>>> +
> >>>>>> +                    }
> >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >>>>>> +                    continue;
> >>>>>> +
> >>>>>> +            } else if (pobj->type == ACPI_TYPE_INTEGER) {
> >>>>>> +                    /*
> >>>>>> +                     * Report "PrerequisiteSize" and "Size" values
> >>>>>> +                     *      ...
> >>>>>> +                     *      "PrerequisiteSize": 1,
> >>>>>> +                     *      ...
> >>>>>> +                     *      "Size": 2,
> >>>>>> +                     *      ...
> >>>>>> +                     */
> >>>>>> +                    if (i == 7)
> >>>>>> +                            size = pobj->integer.value;
> >>>>>> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> >>>>>> 9)
> >>>>>> +                            size = pobj->integer.value;
> >>>>>> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> >>>>>> == 10)
> >>>>>> +                            size = pobj->integer.value;
> >>>>>> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> >>>>>> 11)
> >>>>>> +                            size = pobj->integer.value;
> >>>>>> +
> >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> >>>>>> %lld,\n", buf,
> >>>>>> +                                        hp_wmi_elements[type][i], pobj-
> >>>>>>> integer.value);
> >>>>>> +            }
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    if (type == HPWMI_ENUMERATION_TYPE) {
> >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\":
> >>>>>> [\n", buf);
> >>>>>> +            for (i = 0; i < size; i++) {
> >>>>>> +                    pobj = &(obj->package.elements[i +
> >>>>>> hp_wmi_elements_count[type]]);
> >>>>>> +
> >>>>>> +                    status = convert_hexstr_to_str(&pobj-
> >>>>>>> string.pointer,
> >>>>>> +                                                   pobj->string.length,
> >>>>>> +                                                   &value, &value_len);
> >>>>>> +                    if (ACPI_FAILURE(status))
> >>>>>> +                            break;
> >>>>>> +
> >>>>>> +                    /*
> >>>>>> +                     * Report list of "PossibleValues" of size
> >>>>>> +                     * "Size"
> >>>>>> +                     *      ...
> >>>>>> +                     *      "Size": 2,
> >>>>>> +                     *      "PossibleValues": [
> >>>>>> +                     *                      "Disable",
> >>>>>> +                     *                      "Enable"]
> >>>>>> +                     */
> >>>>>> +                    if (i == (size - 1))
> >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> >>>>>> +                                                "%s\t\t\"%s\"\n", buf,
> >>>>>> value);
> >>>>>> +                    else
> >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> >>>>>> +                                                "%s\t\t\"%s\",\n", buf,
> >>>>>> value);
> >>>>>> +                    kfree(value);
> >>>>>> +                    value = NULL;
> >>>>>> +            }
> >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    if (type == HPWMI_ORDEREDLIST_TYPE) {
> >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n",
> >>>>>> buf);
> >>>>>> +            if (size <= 0)
> >>>>>> +                    goto finish_ordered_list;
> >>>>>> +
> >>>>>> +            pobj = &(obj-
> >>>>>>> package.elements[hp_wmi_elements_count[type]]);
> >>>>>> +            status = convert_hexstr_to_str(&pobj->string.pointer,
> >>>>>> +                                           pobj->string.length, &value,
> >>>>>> &value_len);
> >>>>>> +            if (ACPI_FAILURE(status))
> >>>>>> +                    goto finish_ordered_list;
> >>>>>> +
> >>>>>> +            /*
> >>>>>> +             * Ordered list data is stored in hex and comma separated
> >>>>>> format
> >>>>>> +             * Convert the data and split it to show each element
> >>>>>> +             */
> >>>>>> +            status = convert_hexstr_to_str(&value, value_len, &tmpstr,
> >>>>>> &tmp_len);
> >>>>>> +            if (ACPI_FAILURE(status))
> >>>>>> +                    goto finish_ordered_list;
> >>>>>> +
> >>>>>> +            part_tmp = tmpstr;
> >>>>>> +            part = strsep(&part_tmp, ",");
> >>>>>> +            while (part) {
> >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"",
> >>>>>> buf, part);
> >>>>>> +                    part = strsep(&part_tmp, ",");
> >>>>>> +                    if (part)
> >>>>>> +                            buf_size = snprintf(buf, alloc_size, "%s,\n",
> >>>>>> buf);
> >>>>>> +                    else
> >>>>>> +                            buf_size = snprintf(buf, alloc_size, "%s\n",
> >>>>>> buf);
> >>>>>> +            }
> >>>>>> +    }
> >>>>>> +
> >>>>>> +finish_ordered_list:
> >>>>>> +    if (type == HPWMI_ORDEREDLIST_TYPE)
> >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >>>>>> +
> >>>>>> +    /*
> >>>>>> +     * remove trailing comma
> >>>>>> +     */
> >>>>>> +    if (buf_size > 3)
> >>>>>> +            buf[buf_size - 2] = ' ';
> >>>>>> +
> >>>>>> +    kfree(tmpstr);
> >>>>>> +    kfree(value);
> >>>>>> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> >>>>>> +}
> >>>>>> +
> >>>>>> +static int append_buffer_elements_to_buffer(union acpi_object *obj,
> >>>>>> +                                        char *buf, int alloc_size, enum
> >>>>>> hp_wmi_data_type type)
> >>>>>> +{
> >>>>>> +    int buf_size;
> >>>>>> +    int status;
> >>>>>> +    char *str = NULL;
> >>>>>> +    int i;
> >>>>>> +    int j;
> >>>>>> +    int integer;
> >>>>>> +    int size = 0;
> >>>>>> +
> >>>>>> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> >>>>>> +            return -EINVAL;
> >>>>>> +
> >>>>>> +    if (obj->type != ACPI_TYPE_BUFFER)
> >>>>>> +            return -EINVAL;
> >>>>>> +
> >>>>>> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> >>>>>> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf,
> >>>>>> hp_wmi_classes[type]);
> >>>>>> +
> >>>>>> +    for (i = 0; i < 3; i++) {
> >>>>>> +            status = get_string_from_buffer((u16 **)&obj-
> >>>>>>> buffer.pointer, &str);
> >>>>>> +            if (ACPI_SUCCESS(status)) {
> >>>>>> +                    /*
> >>>>>> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> >>>>>> since
> >>>>>> +                     * 'CurrentValue' is reported.
> >>>>>> +                     */
> >>>>>> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> >>>>>> +                                                "%s\t\"%s\": \"%s\",\n",
> >>>>>> +                                                buf,
> >>>>>> +
> >>>>>> hp_wmi_elements[type][i], str);
> >>>>>> +            }
> >>>>>> +            kfree(str);
> >>>>>> +            str = NULL;
> >>>>>> +
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> >>>>>> +            if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
> >>>>>> +                    status = get_string_from_buffer((u16 **)&obj-
> >>>>>>> buffer.pointer, &str);
> >>>>>> +                    if (ACPI_SUCCESS(status)) {
> >>>>>> +                            /*
> >>>>>> +                             * Report "CurrentValue" as "Value"
> >>>>>> +                             */
> >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> >>>>>> +                                                "%s\t\"Value\": \"%s\",\n",
> >>>>>> buf, str);
> >>>>>> +                    }
> >>>>>> +                    kfree(str);
> >>>>>> +                    str = NULL;
> >>>>>> +                    continue;
> >>>>>> +
> >>>>>> +            } else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
> >>>>>> +                    /*
> >>>>>> +                     * Report list of "SupportEncoding"
> >>>>>> +                     *
> >>>>>> +                     *      "SupportedEncoding": [
> >>>>>> +                     *              "utf-16"
> >>>>>> +                     *      ],
> >>>>>> +                     *
> >>>>>> +                     */
> >>>>>> +
> >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> >>>>>> +                                        buf, hp_wmi_elements[type][i]);
> >>>>>> +                    for (j = 0; j < size; j++) {
> >>>>>> +                            status = get_string_from_buffer((u16
> >>>>>> **)&obj->buffer.pointer, &str);
> >>>>>> +                            if (ACPI_SUCCESS(status)) {
> >>>>>> +                                    if (j == size - 1)
> >>>>>> +                                            buf_size = snprintf(buf,
> >>>>>> alloc_size,
> >>>>>> +
> >>>>>> "%s\t\t\"%s\"\n", buf, str);
> >>>>>> +                                    else
> >>>>>> +                                            buf_size = snprintf(buf,
> >>>>>> alloc_size,
> >>>>>> +
> >>>>>> "%s\t\t\"%s\",\n", buf, str);
> >>>>>> +                            }
> >>>>>> +                            kfree(str);
> >>>>>> +                            str = NULL;
> >>>>>> +                    }
> >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >>>>>> +                    continue;
> >>>>>> +            }
> >>>>>> +
> >>>>>> +            size = 0;
> >>>>>> +            status = get_integer_from_buffer((int **)&obj-
> >>>>>>> buffer.pointer, &integer);
> >>>>>> +            if (ACPI_SUCCESS(status)) {
> >>>>>> +                    /*
> >>>>>> +                     * Report "PrerequisiteSize" and "Size" values
> >>>>>> +                     *      ...
> >>>>>> +                     *      "PrerequisiteSize": 1,
> >>>>>> +                     *      ...
> >>>>>> +                     *      "Size": 2,
> >>>>>> +                     *      ...
> >>>>>> +                     */
> >>>>>> +                    if (i == 7)
> >>>>>> +                            size = integer;
> >>>>>> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> >>>>>> == 10)
> >>>>>> +                            size = integer;
> >>>>>> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> >>>>>> 9)
> >>>>>> +                            size = integer;
> >>>>>> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> >>>>>> 11)
> >>>>>> +                            size = integer;
> >>>>>> +
> >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> >>>>>> %d,\n", buf,
> >>>>>> +                                        hp_wmi_elements[type][i],
> >>>>>> integer);
> >>>>>> +            }
> >>>>>> +
> >>>>>> +            if (size > 20)
> >>>>>> +                    pr_warn("%s exceeded the maximum number of
> >>>>>> elements supported or data may be malformed\n",
> >>>>>> +                            hp_wmi_elements[type][i]);
> >>>>>> +
> >>>>>> +            if (ACPI_SUCCESS(status) && i == 7) {
> >>>>>> +                    buf_size = snprintf(buf, alloc_size,
> >>>>>> "%s\t\"Prerequisites\": [\n", buf);
> >>>>>> +                    for (j = 0; j < size; j++) {
> >>>>>> +                            status = get_string_from_buffer((u16
> >>>>>> **)&obj->buffer.pointer, &str);
> >>>>>> +                            if (ACPI_SUCCESS(status)) {
> >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> >>>>>> "%s\t\t\"%s\"", buf, str);
> >>>>>> +
> >>>>>> +                                    if (j == size - 1)
> >>>>>> +                                            buf_size = snprintf(buf,
> >>>>>> alloc_size, "%s\n", buf);
> >>>>>> +                                    else
> >>>>>> +                                            buf_size = snprintf(buf,
> >>>>>> alloc_size, "%s,\n", buf);
> >>>>>> +
> >>>>>> +                            }
> >>>>>> +                            kfree(str);
> >>>>>> +                            str = NULL;
> >>>>>> +                    }
> >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >>>>>> +            }
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    if (type == HPWMI_ENUMERATION_TYPE || type ==
> >>>>>> HPWMI_ORDEREDLIST_TYPE) {
> >>>>>> +            if (type == HPWMI_ENUMERATION_TYPE)
> >>>>>> +                    buf_size = snprintf(buf, alloc_size,
> >>>>>> "%s\t\"PossibleValues\": [\n", buf);
> >>>>>> +            else
> >>>>>> +                    buf_size = snprintf(buf, alloc_size,
> >>>>>> "%s\t\"Elements\": [\n", buf);
> >>>>>> +
> >>>>>> +            for (i = 0; i < size; i++) {
> >>>>>> +                    status = get_string_from_buffer((u16 **)&obj-
> >>>>>>> buffer.pointer, &str);
> >>>>>> +                    if (ACPI_SUCCESS(status)) {
> >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> >>>>>> "%s\t\t\"%s\"", buf, str);
> >>>>>> +
> >>>>>> +                            if (i == size - 1)
> >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> >>>>>> "%s\n", buf);
> >>>>>> +                            else
> >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> >>>>>> "%s,\n", buf);
> >>>>>> +
> >>>>>> +                    }
> >>>>>> +                    kfree(str);
> >>>>>> +                    str = NULL;
> >>>>>> +            }
> >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    /*
> >>>>>> +     * remove trailing comma
> >>>>>> +     */
> >>>>>> +    if (buf_size > 3)
> >>>>>> +            buf[buf_size - 2] = ' ';
> >>>>>> +
> >>>>>> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> >>>>>> +}
> >>>>>> +
> >>>>>> +static int hp_bios_settings_free_buffer(void)
> >>>>>> +{
> >>>>>> +    mutex_lock(&buf_mutex);
> >>>>>> +    kfree(hp_bios_settings_buffer);
> >>>>>> +    settings_buffer_size = 0;
> >>>>>> +    buf_alloc_size = 0;
> >>>>>> +    mutex_unlock(&buf_mutex);
> >>>>>> +
> >>>>>> +    return 0;
> >>>>>> +}
> >>>>>> +
> >>>>>> +static int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
> >>>>>> +                                       int *alloc_size,
> >>>>>> +                                       struct mutex *buf_mutex)
> >>>>>> +{
> >>>>>> +    int new_buffer_size;
> >>>>>> +    char *new_buf = NULL;
> >>>>>> +    int ret = 0;
> >>>>>> +
> >>>>>> +    if (*buf_size + PAGE_SIZE >= *alloc_size) {
> >>>>>> +            new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
> >>>>>> +
> >>>>>> +            mutex_lock(buf_mutex);
> >>>>>> +            new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
> >>>>>> +            mutex_unlock(buf_mutex);
> >>>>>> +            if (new_buf) {
> >>>>>> +                    mutex_lock(buf_mutex);
> >>>>>> +                    *buf = new_buf;
> >>>>>> +                    *alloc_size = ksize(new_buf);
> >>>>>> +                    mutex_unlock(buf_mutex);
> >>>>>> +            } else {
> >>>>>> +                    hp_bios_settings_free_buffer();
> >>>>>> +                    ret = -ENOMEM;
> >>>>>> +            }
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    return ret;
> >>>>>> +}
> >>>>>> +
> >>>>>> +static int append_settings_to_buffer(char *guid, int type, char **buf,
> >>>>>> +                                 int *buf_size, int *alloc_size,
> >>>>>> +                                 struct mutex *buf_mutex)
> >>>>>> +{
> >>>>>> +    union acpi_object *obj = NULL;
> >>>>>> +    int ret = 0;
> >>>>>> +    int status = 0;
> >>>>>> +    int instance = 0;
> >>>>>> +
> >>>>>> +    /*
> >>>>>> +     * Query all the instances until to receive a AE_BAD_PARAMETER
> >>>>>> +     */
> >>>>>> +    do {
> >>>>>> +            ret = hp_wmi_get_setting_object(guid, instance++, &obj);
> >>>>>> +            if (ACPI_SUCCESS(ret) && obj != NULL) {
> >>>>>> +                    status = 0;
> >>>>>> +                    if (obj->type == ACPI_TYPE_PACKAGE) {
> >>>>>> +                            mutex_lock(buf_mutex);
> >>>>>> +                            status =
> >>>>>> append_package_elements_to_buffer(obj,
> >>>>>> +                                                    *buf, *alloc_size,
> >>>>>> type);
> >>>>>> +                            if (status > 0)
> >>>>>> +                                    *buf_size = status;
> >>>>>> +                            mutex_unlock(buf_mutex);
> >>>>>> +
> >>>>>> +                    } else if (obj->type == ACPI_TYPE_BUFFER) {
> >>>>>> +                            mutex_lock(buf_mutex);
> >>>>>> +                            status =
> >>>>>> append_buffer_elements_to_buffer(obj,
> >>>>>> +                                                    *buf, *alloc_size,
> >>>>>> type);
> >>>>>> +                            if (status > 0)
> >>>>>> +                                    *buf_size = status;
> >>>>>> +                            mutex_unlock(buf_mutex);
> >>>>>> +
> >>>>>> +                    } else
> >>>>>> +                            pr_warn("The retrieved object type(%d) is
> >>>>>> not supported yet\n",
> >>>>>> +                                    obj->type);
> >>>>>> +
> >>>>>> +                    ret = hp_bios_settings_realloc_buffer(buf, buf_size,
> >>>>>> alloc_size, buf_mutex);
> >>>>>> +            }
> >>>>>> +
> >>>>>> +            kfree(obj);
> >>>>>> +            obj = NULL;
> >>>>>> +
> >>>>>> +    } while (ACPI_SUCCESS(ret));
> >>>>>> +
> >>>>>> +    /*
> >>>>>> +     * AE_BAD_PARAMETER means the loop ended by exhaustion
> >>>>>> +     */
> >>>>>> +    if (ret == AE_BAD_PARAMETER)
> >>>>>> +            ret = 0;
> >>>>>> +
> >>>>>> +    return ret;
> >>>>>> +}
> >>>>>> +
> >>>>>> +static int hp_bios_settings_fill_buffer(void)
> >>>>>> +{
> >>>>>> +    int status = 0;
> >>>>>> +    int initial_buffer_size = 20 * PAGE_SIZE;
> >>>>>> +
> >>>>>> +    mutex_lock(&buf_mutex);
> >>>>>> +    hp_bios_settings_buffer = kmalloc(initial_buffer_size,
> >>> GFP_KERNEL);
> >>>>>> +    mutex_unlock(&buf_mutex);
> >>>>>> +    if (!hp_bios_settings_buffer)
> >>>>>> +            return -ENOMEM;
> >>>>>> +
> >>>>>> +    mutex_lock(&buf_mutex);
> >>>>>> +    buf_alloc_size = ksize(hp_bios_settings_buffer);
> >>>>>> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> >>>>>> +                                    buf_alloc_size, "[\n");
> >>>>>> +    mutex_unlock(&buf_mutex);
> >>>>>> +
> >>>>>> +    status = append_settings_to_buffer(HPWMI_STRING_GUID,
> >>>>>> +            HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
> >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >>>>>> +    if (ACPI_FAILURE(status))
> >>>>>> +            pr_err("error 0x%x occurred retrieving string instances\n",
> >>>>>> status);
> >>>>>> +
> >>>>>> +    status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
> >>>>>> +            HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
> >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >>>>>> +    if (ACPI_FAILURE(status))
> >>>>>> +            pr_err("error 0x%x occurred retrieving integer instances\n",
> >>>>>> status);
> >>>>>> +
> >>>>>> +    status =
> >>> append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
> >>>>>> +            HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
> >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >>>>>> +    if (ACPI_FAILURE(status))
> >>>>>> +            pr_err("error 0x%x occurred retrieving enumeration
> >>>>>> instances\n", status);
> >>>>>> +
> >>>>>> +    status = append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
> >>>>>> +            HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
> >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >>>>>> +    if (ACPI_FAILURE(status))
> >>>>>> +            pr_err("error 0x%x occurred retrieving ordered list
> >>>>>> instances\n", status);
> >>>>>> +
> >>>>>> +    status = append_settings_to_buffer(HPWMI_PASSWORD_GUID,
> >>>>>> +            HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
> >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> >>>>>> +    if (ACPI_FAILURE(status))
> >>>>>> +            pr_err("error 0x%x occurred retrieving password list
> >>>>>> instances\n", status);
> >>>>>> +
> >>>>>> +    mutex_lock(&buf_mutex);
> >>>>>> +    /*
> >>>>>> +     * remove trailing comma
> >>>>>> +     */
> >>>>>> +    if (settings_buffer_size >= 3) {
> >>>>>> +            if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
> >>>>>> +                    hp_bios_settings_buffer[settings_buffer_size - 2] = '
> >>>>>> ';
> >>>>>> +    }
> >>>>>> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> >>>>>> +                                    buf_alloc_size, "%s]\n",
> >>>>>> +                                    hp_bios_settings_buffer);
> >>>>>> +    mutex_unlock(&buf_mutex);
> >>>>>> +
> >>>>>> +    return settings_buffer_size;
> >>>>>> +}
> >>>>>> +
> >>>>>> +/*
> >>>>>> + * sure_admin_settings_read - Return a formatted file with settings
> >>>>>> + *                              and possible options read from BIOS
> >>>>>> + *
> >>>>>> + * @filp:  Pointer to file of settings read from BIOS
> >>>>>> + * @kobj:  Pointer to a kernel object of things that show up as directory
> >>> in
> >>>>>> the sysfs filesystem.
> >>>>>> + * @attr:  Pointer to list of read attributes
> >>>>>> + * @buf:   Pointer to buffer
> >>>>>> + * @off:   File current offset
> >>>>>> + * @count: Buffer size
> >>>>>> + *
> >>>>>> + * Returns the count of unicode chars read if successful, otherwise
> >>>>>> + *          -ENOMEM unable to allocate memory
> >>>>>> + *          -EINVAL buffer not allocated or too small
> >>>>>> + *
> >>>>>> + */
> >>>>>> +static ssize_t sure_admin_settings_read(struct file *filp, struct kobject
> >>>>>> *kobj,
> >>>>>> +                                    struct bin_attribute *attr, char *buf,
> >>>>>> loff_t off, size_t count)
> >>>>>> +{
> >>>>>> +    ssize_t ret;
> >>>>>> +
> >>>>>> +    /* clear the buffer when offset is pointing to the last position */
> >>>>>> +    if (off >= settings_buffer_size && settings_buffer_size > 0) {
> >>>>>> +            hp_bios_settings_free_buffer();
> >>>>>> +            return 0;
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    /* clear the buffer whenever the read starts from the first position
> >>>>>> */
> >>>>>> +    if (off == 0 && settings_buffer_size > 0)
> >>>>>> +            hp_bios_settings_free_buffer();
> >>>>>> +
> >>>>>> +    if (settings_buffer_size == 0)
> >>>>>> +            hp_bios_settings_fill_buffer();
> >>>>>> +
> >>>>>> +    mutex_lock(&buf_mutex);
> >>>>>> +    ret = memory_read_from_buffer(buf, count, &off,
> >>>>>> hp_bios_settings_buffer,
> >>>>>> +                                  settings_buffer_size);
> >>>>>> +    mutex_unlock(&buf_mutex);
> >>>>>> +
> >>>>>> +    return ret;
> >>>>>> +}
> >>>>>> +
> >>>>>> +
> >>>>>> +/*
> >>>>>> + * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
> >>>>>> + *
> >>>>>> + * @p:   Unicode buffer address
> >>>>>> + * @str: string to convert to unicode
> >>>>>> + *
> >>>>>> + * Returns a void pointer to the buffer containing unicode string
> >>>>>> + */
> >>>>>> +static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
> >>>>>> +{
> >>>>>> +    int len = strlen(str);
> >>>>>> +
> >>>>>> +    /*
> >>>>>> +     * Add null character when reading an empty string
> >>>>>> +     */
> >>>>>> +    if (len == 0) {
> >>>>>> +            *p++ = 2;
> >>>>>> +            *p++ = (u8)0x00;
> >>>>>> +            return p;
> >>>>>> +    }
> >>>>>> +    *p++ = len * 2;
> >>>>>> +    utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
> >>>>>> +    p += len;
> >>>>>> +
> >>>>>> +    return p;
> >>>>>> +}
> >>>>>> +
> >>>>>> +/*
> >>>>>> + * hp_wmi_set_bios_setting - Set setting's value in BIOS
> >>>>>> + *
> >>>>>> + * @input_buffer: Input buffer address
> >>>>>> + * @input_size:   Input buffer size
> >>>>>> + *
> >>>>>> + * Returns: Count of unicode characters written to BIOS if successful,
> >>>>>> otherwise
> >>>>>> + *          -ENOMEM unable to allocate memory
> >>>>>> + *          -EINVAL buffer not allocated or too small
> >>>>>> + */
> >>>>>> +static int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
> >>>>>> +{
> >>>>>> +    union acpi_object *obj;
> >>>>>> +    struct acpi_buffer input = {input_size, input_buffer};
> >>>>>> +    struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
> >>>>>> +    int ret = 0;
> >>>>>> +
> >>>>>> +    ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID, 0, 1,
> >>>>>> &input, &output);
> >>>>>> +
> >>>>>> +    obj = output.pointer;
> >>>>>> +    if (!obj)
> >>>>>> +            return -EINVAL;
> >>>>>> +
> >>>>>> +    if (obj->type != ACPI_TYPE_INTEGER)
> >>>>>> +            ret = -EINVAL;
> >>>>>> +
> >>>>>> +    ret = obj->integer.value;
> >>>>>> +    kfree(obj);
> >>>>>> +    return ret;
> >>>>>> +}
> >>>>>> +
> >>>>>> +/* Sure Admin Functions */
> >>>>>> +
> >>>>>> +#define UTF_PREFIX                  ((unsigned char *)"<utf-16/>")
> >>>>>> +#define BEAM_PREFIX                 ((unsigned char
> >>>>>> *)"<BEAM/>")
> >>>>>> +
> >>>>>> +/*
> >>>>>> + * sure_admin_settings_write - Write the contents of a formatted file
> >>>>>> + *                               with settings and performs the logic
> >>>>>> + *                               to change any settings in BIOS.
> >>>>>> + *
> >>>>>> + * @filp:  Pointer to file of settings to be written to BIOS
> >>>>>> + * @kobj:  Pointer to a kernel object of things that show up as directory
> >>> in
> >>>>>> the sysfs filesystem.
> >>>>>> + * @attr:  Pointer to list of attributes for the write operation
> >>>>>> + * @buf:   Pointer to buffer
> >>>>>> + * @off:   File current offset
> >>>>>> + * @count: Buffer size
> >>>>>> + *
> >>>>>> + *
> >>>>>> + * Returns the count of unicode characters written to BIOS if
> >>> successful,
> >>>>>> otherwise
> >>>>>> + *          -ENOMEM unable to allocate memory
> >>>>>> + *          -EINVAL buffer not allocated or too small
> >>>>>> + *
> >>>>>> + */
> >>>>>> +static ssize_t sure_admin_settings_write(struct file *filp, struct kobject
> >>>>>> *kobj,
> >>>>>> +                    struct bin_attribute *attr, char *buf, loff_t off, size_t
> >>>>>> count)
> >>>>>> +{
> >>>>>> +    int status = 0;
> >>>>>> +    char *part = NULL;
> >>>>>> +    int part_len = 0;
> >>>>>> +    unsigned short *buffer = NULL;
> >>>>>> +    unsigned short *tmpstr = NULL;
> >>>>>> +    int buffer_size = (count + strlen(UTF_PREFIX)) * sizeof(unsigned
> >>>>>> short);
> >>>>>> +
> >>>>>> +    buffer = kmalloc(buffer_size, GFP_KERNEL);
> >>>>>> +    if (!buffer)
> >>>>>> +            return -ENOMEM;
> >>>>>> +
> >>>>>> +    tmpstr = buffer;
> >>>>>> +    part = strsep(&buf, ",");
> >>>>>> +    if (!part) {
> >>>>>> +            status = -EINVAL;
> >>>>>> +            goto out_free;
> >>>>>> +    }
> >>>>>> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> >>>>>> +    part = strsep(&buf, ",");
> >>>>>> +    if (!part) {
> >>>>>> +            status = -EINVAL;
> >>>>>> +            goto out_free;
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    /* Add extra buffer space when encountering an empty string */
> >>>>>> +    if (!strlen(part))
> >>>>>> +            buffer_size += sizeof(unsigned short);
> >>>>>> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> >>>>>> +    part = strsep(&buf, ",");
> >>>>>> +    if (!part) {
> >>>>>> +            status = -EINVAL;
> >>>>>> +            goto out_free;
> >>>>>> +    }
> >>>>>> +    part_len = strlen(part) - 1;
> >>>>>> +    part[part_len] = '\0';
> >>>>>> +
> >>>>>> +    if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
> >>>>>> +           /*
> >>>>>> +            * BEAM_PREFIX is append to buffer when a signature
> >>>>>> +            * is provided and Sure Admin is enabled in BIOS
> >>>>>> +            */
> >>>>>> +            // BEAM_PREFIX found, convert part to unicode
> >>>>>> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> >>>>>> +            // decrease buffer size allocated initially for UTF_PREFIX
> >>>>>> +            buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
> >>>>>> +    } else {
> >>>>>> +            /*
> >>>>>> +             * UTF-16 prefix is append to the * buffer when a BIOS
> >>>>>> +             * admin password is configured in BIOS
> >>>>>> +             */
> >>>>>> +
> >>>>>> +            // append UTF_PREFIX to part and then convert it to unicode
> >>>>>> +            part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
> >>>>>> +            if (!part)
> >>>>>> +                    goto out_free;
> >>>>>> +
> >>>>>> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> >>>>>> +            kfree(part);
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    part = strsep(&buf, ",");
> >>>>>> +    if (part) {
> >>>>>> +            status = -EINVAL;
> >>>>>> +            goto out_free;
> >>>>>> +    }
> >>>>>> +    status = hp_wmi_set_bios_setting(buffer, buffer_size);
> >>>>>> +    if (ACPI_FAILURE(status))
> >>>>>> +            status = -EINVAL;
> >>>>>> +
> >>>>>> +out_free:
> >>>>>> +    kfree(buffer);
> >>>>>> +    if (ACPI_SUCCESS(status))
> >>>>>> +            return count;
> >>>>>> +    return status;
> >>>>>> +}
> >>>>>> +
> >>>>>> +HPWMI_BINATTR_RW(sure_admin, settings, 0);
> >>>>>> +
> >>>>>> +static struct bin_attribute *sure_admin_binattrs[] = {
> >>>>>> +    &sure_admin_settings,
> >>>>>> +    NULL,
> >>>>>> +};
> >>>>>> +
> >>>>>> +static const struct attribute_group sure_admin_group = {
> >>>>>> +    .name = "sure_admin",
> >>>>>> +    .bin_attrs = sure_admin_binattrs,
> >>>>>> +};
> >>>>>> +
> >>>>>>  static DEVICE_ATTR_RO(display);
> >>>>>>  static DEVICE_ATTR_RO(hddtemp);
> >>>>>>  static DEVICE_ATTR_RW(als);
> >>>>>> @@ -1050,6 +2026,7 @@ static const struct attribute_group
> >>>>>> *hp_wmi_groups[] = {
> >>>>>>      &hp_wmi_group,
> >>>>>>      &spm_group,
> >>>>>>      &sure_start_group,
> >>>>>> +    &sure_admin_group,
> >>>>>>      NULL,
> >>>>>>  };
> >>>>>>
> >>>>>> --
> >>>>>> 2.25.1
> >>>>
> >
>

Mario Limonciello April 8, 2022, 2:54 p.m. UTC | #10

[Public]



> -----Original Message-----
> From: Jorge Lopez <[e-mail]>
> Sent: Friday, April 8, 2022 09:47
> To: Hans de Goede <[e-mail]>
> Cc: Limonciello, Mario <[e-mail]>; platform-driver-
> [e-mail]
> Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
> 
> On Fri, Apr 8, 2022 at 4:21 AM Hans de Goede <[e-mail]>
> wrote:
> >
> > Hi Jorge,
> >
> > On 4/7/22 15:44, Jorge Lopez wrote:
> > > Hans, Mario,
> > >
> > > The code links make references to code that implements the new
> > > interfaces but there's
> > > still code in the kernel that uses the old ones.
> >
> > I'm not sure what you mean with "uses the old ones" there never
> > has been any kernel drivers for changing BIOS settings before
> > the dell and lenovo drivers were merged.
> 
> "uses the old ones" statement means that there are drivers on the tree
> that change BIOS settings without having to convert to the new
> standards.  hp-wmi remained unsupported for many years so I can
> understand why the security features need to use the standardized API.
> 
> >
> > Sure there are generic mechanisms like chardev-s and ioctls which
> > are used for a whole bunch of things. But AFAIK there never was
> > an API specifically for changing BIOS settings before.
> >
> > > I do agree we should
> > > be forward looking
> > > and want to be good participants in the kernel development, but can't
> > > let our immediate
> > > business needs be impacted with opportunities to enhance the driver to
> > > take advantage
> > > of the latest kernel features.
> > >
> > > Rewriting those security features will impact customer business
> > > datelines requiring
> > > HP to provide private releases as the kernel version changes.   The
> > > requested changes
> > > will impact products in the market and HP ability to help customers to
> > > migrate to Linux
> > > from Windows products.
> >
> > This sounds like you are saying that you are already shipping
> > a version of the driver with the non-standard API to customers.
> > Shipping code to customers before even proposing it upstream is
> > HP own choice and the results of that as such are HP's
> > responsibility.
> >
> The products shipped to customers are Windows products and customers
> are accustomed to how the data is reported and set.  The goal for the
> new security features in Linux is to help those customers migrate to
> Linux with little or no change to their scripts/tools.

I think if this is the situation then a userspace compatibility /conversion tool is
your better answer than a large compatibility layer in debugfs.

From the customer perspective they just need to see that JSON file in/out, right?
So you should be able to write a tool/script that parses all the attributes from
sysfs in a high level language and puts them into a JSON payload for their scripts
to work from.  Likewise it should be able to parse a JSON payload and deploy
all of that stuff into the standard API.

You can also explain in your documentation associates with such a tool/script
that it's using a standard API and if they want to use that API directly instead
of your compatibility tool they're welcome to do so.

> 
> > You cannot just say we are already shipping this so we need
> > the upstream kernel to support this non standard API, that is
> > not how upstream kernel development works.
> >
> > I realize that HP is new to working directly with the upstream kernel
> > community and I realize that being told that the API which you are
> > already using cannot be used for upstreaming your driver is not what
> > you want to hear.
> >
> > But that does not change that I cannot accept a driver which does not
> > implement the standard API which the upstream kernel community has
> > agreed upon for this functionality.
> >
> > Or as Mario very elegantly put it:
> >
> > 'Keep in mind that from an upstream kernel perspective this driver is
> "new".
> > There is no requirements from the upstream perspective to
> > keep your old interfaces in place from when it was out of tree.'
> >
> > > It is because of the immediate business needs, avoiding impacting our
> > > customers/products,
> > > and rewriting  enhancements to the driver that I need to propose an
> > > interim solution.
> > >
> > > My proposal is to introduce a read/write value accessible in the user
> > > space to control how
> > > the driver reports and handles BIOS settings and values.  The new
> > > configuration features
> > > will be gradually disabled  as they are converted to use the standardized
> API.
> > > It is like the configuration flag used to overcome the tablet detection
> problem
> > > introduced in the past.   The changes solely affect the HP WMI driver.
> > > This option will help us
> > > move forward for this release and give us time to make the necessary
> > > changes to both
> > > the driver and support applications.
> > >
> > > Please let me know if this is a viable interim solution.
> >
> > First of all to be very clear, any code going upstream must support
> > the standard API:
> >
> >
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7Cb0dd9
> 6dde69d48c4e60c08da196ea2e1%7C3dd8961fe4884e608e11a82d994e183d%7
> C0%7C0%7C637850260243195656%7CUnknown%7CTWFpbGZsb3d8eyJWIjoi
> MC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C300
> 0&amp;sdata=HDIa3CmOAhty7ZtwAoKh5VveEGCC%2Fuq5E1rx0hWOHns%3
> D&amp;reserved=0
> >
> > from day one. I'm not really enthusiastic about the concept of also
> > supporting the API which you have been using out of tree so far, but
> > I guess that Mario's suggestion to offer a Kconfig option which
> > when enabled offers this API under debugfs might be an acceptible
> > compromise. I would need to see the actual code for that though to
> > see if this is acceptable.
> >
> > And there would need to be a clear cut-of date document after which
> > the code to support the old API will be removed.
> >
> > > If it is not possible, I need to ask where the actual written
> > > requirement is found so I can
> > > include them in the business justification for changes and release
> > > delays to management.
> >
> > I'm not sure if this is written down somewhere, but certainly
> > you will agree that if you were submitting a driver for a soundcard
> > that that should use the existing ALSA userspace API for sound so
> > that it would just work with the existing userspace sound support.
> >
> > This is the same. If an existing standardized userspace API exists
> > for a certain functionality then that userspace API _must_ be used,
> > AFAIK this is not explictly written down anywhere because it is just
> > very much common sense.
> 
> I completely agree with your comments and request for the driver to
> implement the standardized API.  hp-wmi remained unsupported for many
> years so I can understand why the security features need to use the
> standardized API.  I am having conversations with other teams on how
> to move forward with the standard API and how the data is handled and
> reported.   We will submit a new set of patches utilizing the new
> standard at a later time.   Would it be accurate to state that any
> extensions to the standardized API model are acceptable, Correct?
> 

That's correct.  Dell did the first driver, and then Lenovo did the second.
The majority of the features from the Dell driver applied to the Lenovo one
and any idiosyncrasies were introduced as new sysfs files or documented and
agreed different behaviors of others.

> Regards,
> 
> Jorge
> >
> > Regards,
> >
> > Hans
> >
> >
> >
> >
> >
> >
> > > On Tue, Apr 5, 2022 at 12:13 PM Limonciello, Mario
> > > <[e-mail]> wrote:
> > >>
> > >> [Public]
> > >>
> > >>
> > >>
> > >>> -----Original Message-----
> > >>> From: Jorge Lopez <[e-mail]>
> > >>> Sent: Tuesday, April 5, 2022 11:52
> > >>> To: Hans de Goede <[e-mail]>
> > >>> Cc: Limonciello, Mario <[e-mail]>; platform-
> driver-
> > >>> [e-mail]
> > >>> Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
> > >>>
> > >>> Hi Hans,
> > >>>
> > >>> On Tue, Apr 5, 2022 at 6:54 AM Hans de Goede
> <[e-mail]>
> > >>> wrote:
> > >>>>
> > >>>> Hi,
> > >>>>
> > >>>> On 4/4/22 23:59, Limonciello, Mario wrote:
> > >>>>> [Public]
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>> -----Original Message-----
> > >>>>>> From: Jorge Lopez <[e-mail]>
> > >>>>>> Sent: Monday, April 4, 2022 15:36
> > >>>>>> To: [e-mail]
> > >>>>>> Subject: [PATCH v1 5/6] Sure Admin Security Feature
> > >>>>>>
> > >>>>>> HP Commercial PC's have several BIOS settings that control its
> > >>>>>> behaviour and capabilities, many of which are related to security.
> To
> > >>>>>> prevent unauthorized changes to these settings, the system can
> be
> > >>>>>> configured to use a Sure Admin cryptographic signature-based
> > >>>>>> authorization string that the BIOS will use to verify authorization to
> > >>>>>> modify the setting. Behind the scenes, Sure Admin uses Secure
> > >>> Platform
> > >>>>>> Management (SPM) and WMI
> > >>>>>>
> > >>>>>> 'settings' is a file associated with Sure Admin. BIOS settings can be
> > >>>>>> read or written through the Sure Admin settings file in sysfs
> > >>>>>>
> > >>>>>>      /sys/devices/platform/hp-wmi/sure_admin/settings
> > >>>>>>
> > >>>>>> Expected data format to update BIOS setting
> > >>>>>>
> > >>>>>>      [BIOS setting],[new value],[auth token]
> > >>>>>>
> > >>>>>> Sample settings reported data
> > >>>>>>
> > >>>>>>      {
> > >>>>>>              "Class": "HPBIOS_BIOSEnumeration",
> > >>>>>>              "Name": "USB Storage Boot",
> > >>>>>>              "Path": "\\Advanced\\Boot Options",
> > >>>>>>              "IsReadOnly": 0,
> > >>>>>>              ...
> > >>>>>>              "Value": "Enable",
> > >>>>>>              "Size": 2,
> > >>>>>>              "PossibleValues": [
> > >>>>>>                      "Disable",
> > >>>>>>                      "Enable"
> > >>>>>>              ]
> > >>>>>>      }
> > >>>>>>
> > >>>>>
> > >>>>> This sounds like it has re-invented /sys/class/firmware-attributes.
> > >>>>>
> > >>>>> Shouldn't you adopt that API?
> > >>>>
> > >>>> I fully agree. Jorge as I already indicated in our off-list
> > >>>> conversation when you initially started working on this
> > >>>> feature, we already have a standardized API for querying/changing
> > >>>> BIOS settings from within Linux:
> > >>>>
> > >>>
> > >>> I agree that changing the BIOS settings from within Linux could
> > >>> utilize the new methodology,  I will need to look closely at the
> > >>> requirements before I can proceed to make the changes.
> > >>> Keep in mind authentication of the values is done by BIOS.  No Linux
> > >>> process validates any data name, value, or auth token; only BIOS.  All
> > >>> data written to the sysfs file is not validated, it is just forward to
> > >>> BIOS.  See spm_kek_store and spm_sk_store functions.
> > >>
> > >> That's fine, and it's a safer design to have BIOS validate it.
> > >>
> > >>> One point I must make clear when updating BIOS settings.  any  NOT
> > >>> read-only BIOS settings can be changed by the application at any time.
> > >>>    This list of settings changes from one system to another.
> > >>
> > >> Right.
> > >>
> > >>>
> > >>> I am in disagreement with reading the settings.  hp-wmi does not read
> > >>> one value at a time. It reads all values exposed by BIOS.  See
> > >>> attached sample output.
> > >>
> > >> The settings can all be read at initialization time for the driver and
> cached
> > >> then.
> > >>
> > >>> The method for how all BIOS settings are reported needs to match the
> > >>> method how Windows products do it.  It is a requirement to start
> > >>> migrating customers from Windows to Linux while minimizing how
> BIOS
> > >>> data is reported.
> > >>
> > >> Because we have a standardized API in Linux for this, I think it's best to
> abstract
> > >> this behind a userspace application/script.  If they expect to see it in the
> format you
> > >> showed, the userspace application can take the data from Linux and
> package it that
> > >> way.
> > >>
> > >> You'll have richer libraries and languages and tools to work from when
> doing this too.
> > >> It should make it a lot less painful.
> > >>
> > >>>
> > >>> I will investigate the new API and bring it to the team's attention.
> > >>>
> > >>>>
> > >>>
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> %2F&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7Cb0dd96dde
> 69d48c4e60c08da196ea2e1%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> 7C0%7C637850260243195656%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> mp;sdata=RDJFrHlrsTnb6mvH77dxXYRXclateWBOXLWnc6GQm3c%3D&amp;r
> eserved=0
> > >>>
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > >>> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> > >>>
> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
> > >>>
> f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
> > >>>
> 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> > >>>
> C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
> > >>>
> &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
> > >>> D&amp;reserved=0
> > >>>>
> > >>>> and any new code (such as this patch) which implements BIOS
> > >>>> setting changing MUST follow this standardized API (extending
> > >>>> it where necessary).
> > >>>>
> > >>>> I'm sorry but this patch is not acceptable in its current form,
> > >>>> it needs to be *completely rewritten* to implement:
> > >>>>
> > >>>>
> > >>>
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> %2F&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7Cb0dd96dde
> 69d48c4e60c08da196ea2e1%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> 7C0%7C637850260243195656%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> mp;sdata=RDJFrHlrsTnb6mvH77dxXYRXclateWBOXLWnc6GQm3c%3D&amp;r
> eserved=0
> > >>>
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > >>> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
> > >>>
> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12
> > >>>
> f8fea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C
> > >>>
> 0%7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> > >>>
> C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000
> > >>>
> &amp;sdata=QhkFIYFCRXg1seDPb3qhk5qMkNQ%2B8AQXmHuke0YrWKc%3
> > >>> D&amp;reserved=0
> > >>>>
> > >>>> See:
> > >>>>
> > >>>>
> > >>>
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> %2F&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7Cb0dd96dde
> 69d48c4e60c08da196ea2e1%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> 7C0%7C637850260243195656%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> mp;sdata=RDJFrHlrsTnb6mvH77dxXYRXclateWBOXLWnc6GQm3c%3D&amp;r
> eserved=0
> > >>>
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > >>> 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fdell%2Fdell-wmi-
> > >>>
> sysman&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8f
> > >>>
> ea104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> > >>>
> 7C0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> > >>>
> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> > >>>
> mp;sdata=z5jmH7ECYBeLcndQ2vfHaUuyE04Eaf1Lymh6BjnyJ%2Fk%3D&amp;r
> > >>> eserved=0
> > >>>>
> > >>>
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> %2F&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7Cb0dd96dde
> 69d48c4e60c08da196ea2e1%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> 7C0%7C637850260243195656%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> mp;sdata=RDJFrHlrsTnb6mvH77dxXYRXclateWBOXLWnc6GQm3c%3D&amp;r
> eserved=0
> > >>>
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > >>> 2Ftree%2Fdrivers%2Fplatform%2Fx86%2Fthink-
> > >>>
> lmi.c&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea
> > >>>
> 104034282708da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C
> > >>>
> 0%7C637847743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLj
> > >>>
> AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;
> > >>>
> sdata=5n6w9LEB2iWpj1cOQP6Ngz94AqP1Bu4vu8T0EdN%2FThU%3D&amp;re
> > >>> served=0
> > >>>>
> > >>>> for example code / for 2 drivers from other vendors already
> > >>>> implementing this.
> > >>>>
> > >>>> The same applies to the:
> > >>>>
> > >>>> "[PATCH v1 3/6] Secure Platform Management Security Feature"
> > >>>>
> > >>>> this needs to be implemented as
> > >>>> a /sys/class/firmware-attributes/*/authentication/
> > >>>> authentication method, see for example these Lenovo specific
> > >>>> addition to the /sys/class/firmware-attributes/*/authentication/
> > >>>> userspace API for similar functionality on Lenovo Think* devices:
> > >>>>
> > >>>>
> > >>>
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> %2F&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7Cb0dd96dde
> 69d48c4e60c08da196ea2e1%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> 7C0%7C637850260243195656%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a
> mp;sdata=RDJFrHlrsTnb6mvH77dxXYRXclateWBOXLWnc6GQm3c%3D&amp;r
> eserved=0
> > >>>
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
> > >>>
> 2Fcommit%2F%3Fid%3D06384573a3e8335ac6797577e545c33dbf91b490&amp;
> > >>>
> data=04%7C01%7CMario.Limonciello%40amd.com%7C43a12f8fea1040342827
> > >>>
> 08da1724a70c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C63784
> > >>>
> 7743455947225%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLC
> > >>>
> JQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=eldS
> > >>>
> 4H3Z%2BAyL%2FG%2FO9W9rDGC37yh5sGgtUhpKdUAoSmA%3D&amp;reser
> > >>> ved=0
> > >>>>
> > >>>> I'll merge patches 1-2 sometime this week since those are
> > >>>> fine and it will be good to have those "out of the way",
> > >>>> but the rest of the series will need to be rewritten
> > >>>> taken the above comments into account.
> > >>>
> > >>> v1-0003-Sure-Start-Security-Feature.patch  reports the number of
> audit
> > >>> logs available and reports them when read.    it does not read/write
> > >>> BIOS settings hence it does not fall within the same category as
> > >>> patches v1-0002-Secure-Platform-Management-Security-
> Feature.patch and
> > >>> v1-0004-Sure-Admin-Security-Feature.patch
> > >>> Do you agree?
> > >>>
> > >>>>
> > >>>> Regards,
> > >>>>
> > >>>> Hans
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>>
> > >>>>>> This feature requires "Update hp_wmi_group to simplify feature
> > >>>>>> addition" patch.
> > >>>>>>
> > >>>>>> All changes were validated on a HP ZBook Workstation,
> > >>>>>> HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
> > >>>>>>
> > >>>>>> Signed-off-by: Jorge Lopez <[e-mail]>
> > >>>>>>
> > >>>>>> ---
> > >>>>>> Based on the latest platform-drivers-x86.git/for-next
> > >>>>>> ---
> > >>>>>>  drivers/platform/x86/hp-wmi.c | 977
> > >>>>>> ++++++++++++++++++++++++++++++++++
> > >>>>>>  1 file changed, 977 insertions(+)
> > >>>>>>
> > >>>>>> diff --git a/drivers/platform/x86/hp-wmi.c
> b/drivers/platform/x86/hp-
> > >>> wmi.c
> > >>>>>> index 918e3eaf1b67..b72ca18b77a6 100644
> > >>>>>> --- a/drivers/platform/x86/hp-wmi.c
> > >>>>>> +++ b/drivers/platform/x86/hp-wmi.c
> > >>>>>> @@ -27,6 +27,7 @@
> > >>>>>>  #include <linux/rfkill.h>
> > >>>>>>  #include <linux/string.h>
> > >>>>>>  #include <linux/dmi.h>
> > >>>>>> +#include <linux/nls.h>
> > >>>>>>
> > >>>>>>  MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
> > >>>>>>  MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
> > >>>>>> @@ -37,8 +38,16 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-
> BE91-
> > >>>>>> 3D44E2C707E4");
> > >>>>>>
> > >>>>>>  #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-
> > >>> ACCDC67EF61C"
> > >>>>>>  #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-
> > >>> 3D44E2C707E4"
> > >>>>>> +
> > >>>>>>  #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
> > >>>>>>
> > >>>>>> +#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-
> > >>> 6A1B8106F83C"
> > >>>>>> +#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-
> > >>>>>> E293ADB9BF05"
> > >>>>>> +#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-
> B8FE-
> > >>>>>> 4A3C09E75133"
> > >>>>>> +#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-
> A0E0-
> > >>>>>> 7045CB4DA745"
> > >>>>>> +#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-
> > >>>>>> 015176049E2D"
> > >>>>>> +#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-
> 951D-
> > >>>>>> C7CB9B4B8D5E"
> > >>>>>> +
> > >>>>>>  /* DMI board names of devices that should use the omen specific
> path
> > >>> for
> > >>>>>>   * thermal profiles.
> > >>>>>>   * This was obtained by taking a look in the windows omen
> command
> > >>> center
> > >>>>>> @@ -1025,6 +1034,973 @@ static const struct attribute_group
> > >>>>>> sure_start_group = {
> > >>>>>>      .attrs = sure_start_attrs,
> > >>>>>>  };
> > >>>>>>
> > >>>>>> +
> > >>>>>> +static int convert_hexstr_to_str(char **hex, int input_len, char
> **str,
> > >>> int
> > >>>>>> *len)
> > >>>>>> +{
> > >>>>>> +    int ret = 0;
> > >>>>>> +    int new_len = 0;
> > >>>>>> +    char tmp[] = "0x00";
> > >>>>>> +    char *input = *hex;
> > >>>>>> +    char *new_str = NULL;
> > >>>>>> +    int  ch;
> > >>>>>> +    int i;
> > >>>>>> +
> > >>>>>> +    if (input_len <= 0 || hex == NULL || str == NULL || len ==
> NULL)
> > >>>>>> +            return -EINVAL;
> > >>>>>> +
> > >>>>>> +    *len = 0;
> > >>>>>> +    *str = NULL;
> > >>>>>> +
> > >>>>>> +    new_str = kmalloc(input_len, GFP_KERNEL);
> > >>>>>> +    if (!new_str)
> > >>>>>> +            return -ENOMEM;
> > >>>>>> +
> > >>>>>> +    for (i = 0; i < input_len; i += 5) {
> > >>>>>> +            strncpy(tmp, input + i, strlen(tmp));
> > >>>>>> +            ret = kstrtoint(tmp, 16, &ch);
> > >>>>>> +            if (ret) {
> > >>>>>> +                    new_len = 0;
> > >>>>>> +                    break;
> > >>>>>> +            }
> > >>>>>> +
> > >>>>>> +            if (ch == '\\')
> > >>>>>> +                    new_str[new_len++] = '\\';
> > >>>>>> +
> > >>>>>> +            new_str[new_len++] = ch;
> > >>>>>> +            if (ch == '\0')
> > >>>>>> +                    break;
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    if (new_len) {
> > >>>>>> +            new_str[new_len] = '\0';
> > >>>>>> +            *str = krealloc(new_str, (new_len + 1) * sizeof(char),
> > >>>>>> GFP_KERNEL);
> > >>>>>> +            if (*str)
> > >>>>>> +                    *len = new_len;
> > >>>>>> +            else
> > >>>>>> +                    ret = -ENOMEM;
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    if (ret)
> > >>>>>> +            kfree(new_str);
> > >>>>>> +    return ret;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +/*
> > >>>>>> + * hp_wmi_get_setting_object() - Get an ACPI object by GUID
> and
> > >>> instance
> > >>>>>> + *
> > >>>>>> + * @guid:   GUID associated with the ACPI list of managed objects
> > >>>>>> + * @instance:       Instance index to query on the ACPI list
> > >>>>>> + * @obj:    The output ACPI object of type ACPI_TYPE_PACKAGE
> > >>>>>> + *          or ACPI_TYPE_BUFFER (freed by the callee)
> > >>>>>> + *
> > >>>>>> + * Returns  zero on success.  Otherwise,an error inherited from
> > >>>>>> + *          wmi_query_block(). It returns a obj by parameter if
> > >>>>>> + *          the query returned object of type buffer or package,
> > >>>>>> + *          otherwise, a null obj is returned.
> > >>>>>> + *
> > >>>>>> + * Note: obj should be freed by the callee once it is finished
> working
> > >>> with it
> > >>>>>> + */
> > >>>>>> +static int hp_wmi_get_setting_object(char *guid, int instance,
> > >>>>>> +                            union acpi_object **obj)
> > >>>>>> +{
> > >>>>>> +    struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER,
> NULL
> > >>>>>> };
> > >>>>>> +    union acpi_object *tmp = NULL;
> > >>>>>> +    int ret;
> > >>>>>> +
> > >>>>>> +    ret = wmi_query_block(guid, instance, &output);
> > >>>>>> +    if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
> > >>>>>> +            tmp = output.pointer;
> > >>>>>> +            if (tmp->type == ACPI_TYPE_BUFFER || tmp->type ==
> > >>>>>> ACPI_TYPE_PACKAGE)
> > >>>>>> +                    *obj = output.pointer;
> > >>>>>> +            else {
> > >>>>>> +                    kfree(tmp);
> > >>>>>> +                    *obj = NULL;
> > >>>>>> +            }
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    return ret;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +
> > >>>>>> +static int get_string_from_buffer(u16 **buffer, char **str)
> > >>>>>> +{
> > >>>>>> +    u16 *ptr = *buffer;
> > >>>>>> +    u16 ptrlen;
> > >>>>>> +
> > >>>>>> +    u16 size;
> > >>>>>> +    int i;
> > >>>>>> +    char *output = NULL;
> > >>>>>> +    int escape = 0;
> > >>>>>> +
> > >>>>>> +    ptrlen = *(ptr++);
> > >>>>>> +    size = ptrlen / 2;
> > >>>>>> +
> > >>>>>> +    if (size == 0)
> > >>>>>> +            goto cleanup_exit;
> > >>>>>> +
> > >>>>>> +    for (i = 0; i < size; i++)
> > >>>>>> +            if (ptr[i] == '\\')
> > >>>>>> +                    escape++;
> > >>>>>> +
> > >>>>>> +    size += escape;
> > >>>>>> +    *str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
> > >>>>>> +    if (!*str)
> > >>>>>> +            return -ENOMEM;
> > >>>>>> +
> > >>>>>> +    output = *str;
> > >>>>>> +
> > >>>>>> +    /*
> > >>>>>> +     * convert from UTF-16 unicode to ASCII
> > >>>>>> +     */
> > >>>>>> +    utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output,
> size);
> > >>>>>> +
> > >>>>>> +    if (escape == 0) {
> > >>>>>> +            ptr += (ptrlen / 2);
> > >>>>>> +            goto cleanup_exit;
> > >>>>>> +    }
> > >>>>>> +    /*
> > >>>>>> +     * Convert escape characters only when found
> > >>>>>> +     */
> > >>>>>> +    for (i = 0; i < size; i++) {
> > >>>>>> +            if (*ptr == '\\')
> > >>>>>> +                    output[i++] = '\\';
> > >>>>>> +            output[i] = *ptr;
> > >>>>>> +            ptr++;
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +cleanup_exit:
> > >>>>>> +    *buffer = ptr;
> > >>>>>> +    return 0;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +static int get_integer_from_buffer(int **buffer, int *integer)
> > >>>>>> +{
> > >>>>>> +    int *ptr = PTR_ALIGN(*buffer, 4);
> > >>>>>> +    *integer = *(ptr++);
> > >>>>>> +    *buffer = ptr;
> > >>>>>> +    return 0;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +
> > >>>>>> +// Sure Admin functions
> > >>>>>> +enum hp_wmi_data_type {
> > >>>>>> +    HPWMI_STRING_TYPE,
> > >>>>>> +    HPWMI_INTEGER_TYPE,
> > >>>>>> +    HPWMI_ENUMERATION_TYPE,
> > >>>>>> +    HPWMI_ORDEREDLIST_TYPE,
> > >>>>>> +    HPWMI_PASSWORD_TYPE,
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +#define HP_WMI_COMMON_ELEMENTS      \
> > >>>>>> +    "Name", \
> > >>>>>> +    "Value",        \
> > >>>>>> +    "Path", \
> > >>>>>> +    "IsReadOnly",   \
> > >>>>>> +    "DisplayInUI",  \
> > >>>>>> +    "RequiresPhysicalPresence",     \
> > >>>>>> +    "Sequence",     \
> > >>>>>> +    "PrerequisiteSize",     \
> > >>>>>> +    "SecurityLevel"
> > >>>>>> +
> > >>>>>> +const char *hp_wmi_string_elements[] = {
> > >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> > >>>>>> +    "MinLength",
> > >>>>>> +    "MaxLength"
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +const char *hp_wmi_integer_elements[] = {
> > >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> > >>>>>> +    "LowerBound",
> > >>>>>> +    "UpperBound",
> > >>>>>> +    "IntValue"
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +const char *hp_wmi_enumeration_elements[] = {
> > >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> > >>>>>> +    "CurrentValue",
> > >>>>>> +    "Size"
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +const char *hp_wmi_orderedlist_elements[] = {
> > >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> > >>>>>> +    "Size"
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +const char *hp_wmi_password_elements[] = {
> > >>>>>> +    HP_WMI_COMMON_ELEMENTS,
> > >>>>>> +    "MinLength",
> > >>>>>> +    "MaxLength",
> > >>>>>> +    "Size",
> > >>>>>> +    "SupportedEncoding",
> > >>>>>> +    "IsSet"
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +const char **hp_wmi_elements[] = {
> > >>>>>> +    hp_wmi_string_elements,
> > >>>>>> +    hp_wmi_integer_elements,
> > >>>>>> +    hp_wmi_enumeration_elements,
> > >>>>>> +    hp_wmi_orderedlist_elements,
> > >>>>>> +    hp_wmi_password_elements
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +const int hp_wmi_elements_count[] = {
> > >>>>>> +    ARRAY_SIZE(hp_wmi_string_elements),
> > >>>>>> +    ARRAY_SIZE(hp_wmi_integer_elements),
> > >>>>>> +    ARRAY_SIZE(hp_wmi_enumeration_elements),
> > >>>>>> +    ARRAY_SIZE(hp_wmi_orderedlist_elements),
> > >>>>>> +    ARRAY_SIZE(hp_wmi_password_elements)
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +const char *hp_wmi_classes[] = {
> > >>>>>> +    "HPBIOS_BIOSString",
> > >>>>>> +    "HPBIOS_BIOSInteger",
> > >>>>>> +    "HPBIOS_BIOSEnumeration",
> > >>>>>> +    "HPBIOS_BIOSOrderedList",
> > >>>>>> +    "HPBIOS_BIOSPassword"
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +static DEFINE_MUTEX(buf_mutex);
> > >>>>>> +static int settings_buffer_size;
> > >>>>>> +static int buf_alloc_size;
> > >>>>>> +static char *hp_bios_settings_buffer;
> > >>>>>> +
> > >>>>>> +
> > >>>>>> +static int append_package_elements_to_buffer(union
> acpi_object
> > >>> *obj,
> > >>>>>> +                                         char *buf, int alloc_size, enum
> > >>>>>> hp_wmi_data_type type)
> > >>>>>> +{
> > >>>>>> +    int i;
> > >>>>>> +    union acpi_object *pobj = NULL;
> > >>>>>> +    char *value = NULL;
> > >>>>>> +    int value_len;
> > >>>>>> +    char *tmpstr = NULL;
> > >>>>>> +    char *part_tmp = NULL;
> > >>>>>> +    int tmp_len = 0;
> > >>>>>> +    char *part = NULL;
> > >>>>>> +    int status = 0;
> > >>>>>> +    int size = 0;
> > >>>>>> +    int buf_size;
> > >>>>>> +
> > >>>>>> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> > >>>>>> +            return -EINVAL;
> > >>>>>> +
> > >>>>>> +    if (obj->type != ACPI_TYPE_PACKAGE)
> > >>>>>> +            return -EINVAL;
> > >>>>>> +
> > >>>>>> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> > >>>>>> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n",
> buf,
> > >>>>>> hp_wmi_classes[type]);
> > >>>>>> +
> > >>>>>> +    for (i = 0; i < 3; i++) {
> > >>>>>> +            pobj = &(obj->package.elements[i]);
> > >>>>>> +            if (pobj->type == ACPI_TYPE_STRING) {
> > >>>>>> +                    status = convert_hexstr_to_str(&pobj-
> > >>>>>>> string.pointer,
> > >>>>>> +                                                   pobj->string.length,
> > >>>>>> &value, &value_len);
> > >>>>>> +                    if (ACPI_FAILURE(status))
> > >>>>>> +                            continue;
> > >>>>>> +                    /*
> > >>>>>> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> > >>>>>> since
> > >>>>>> +                     * 'CurrentValue' is reported.
> > >>>>>> +                     */
> > >>>>>> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> > >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> > >>>>>> +                                                "%s\t\"%s\": \"%s\",\n",
> > >>>>>> +                                                buf,
> > >>>>>> +
> > >>>>>> hp_wmi_elements[type][i], value);
> > >>>>>> +
> > >>>>>> +            }
> > >>>>>> +            kfree(value);
> > >>>>>> +            value = NULL;
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> > >>>>>> +            pobj = &(obj->package.elements[i]);
> > >>>>>> +
> > >>>>>> +            if (type == HPWMI_ENUMERATION_TYPE &&
> > >>>>>> +                i == 9 &&
> > >>>>>> +                pobj->type == ACPI_TYPE_STRING) {
> > >>>>>> +                    /*
> > >>>>>> +                     * Report "CurrentValue" as "Value"
> > >>>>>> +                     */
> > >>>>>> +                    status = convert_hexstr_to_str(&pobj-
> > >>>>>>> string.pointer,
> > >>>>>> +                                                   pobj->string.length,
> > >>>>>> +                                                   &value, &value_len);
> > >>>>>> +                    if (ACPI_FAILURE(status))
> > >>>>>> +                            continue;
> > >>>>>> +
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> +                                        "%s\t\"Value\": \"%s\",\n",
> > >>>>>> +                                        buf, value);
> > >>>>>> +                    kfree(value);
> > >>>>>> +                    value = NULL;
> > >>>>>> +
> > >>>>>> +            } else if (type == HPWMI_PASSWORD_TYPE &&
> > >>>>>> +                       i == 12 &&
> > >>>>>> +                       pobj->type == ACPI_TYPE_STRING) {
> > >>>>>> +                    /*
> > >>>>>> +                     * Report list of "SupportEncoding"
> > >>>>>> +                     *
> > >>>>>> +                     *      "SupportedEncoding": [
> > >>>>>> +                     *              "utf-16"
> > >>>>>> +                     *      ],
> > >>>>>> +                     *
> > >>>>>> +                     */
> > >>>>>> +
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> > >>>>>> +                                        buf, hp_wmi_elements[type][i]);
> > >>>>>> +                    while (size--) {
> > >>>>>> +                            pobj = &(obj->package.elements[i]);
> > >>>>>> +                            status = convert_hexstr_to_str(&pobj-
> > >>>>>>> string.pointer,
> > >>>>>> +                                                           pobj-
> > >>>>>>> string.length,
> > >>>>>> +                                                           &value,
> > >>>>>> &value_len);
> > >>>>>> +                            if (ACPI_FAILURE(status))
> > >>>>>> +                                    continue;
> > >>>>>> +
> > >>>>>> +                            if (size) {
> > >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> +                                                        "%s\t\t\"%s\",\n",
> > >>>>>> buf, value);
> > >>>>>> +                                    i++;
> > >>>>>> +                            } else
> > >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> +                                                        "%s\t\t\"%s\"\n",
> > >>>>>> buf, value);
> > >>>>>> +
> > >>>>>> +                            kfree(value);
> > >>>>>> +                            value = NULL;
> > >>>>>> +
> > >>>>>> +                    }
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >>>>>> +                    continue;
> > >>>>>> +
> > >>>>>> +            } else if (pobj->type == ACPI_TYPE_INTEGER) {
> > >>>>>> +                    /*
> > >>>>>> +                     * Report "PrerequisiteSize" and "Size" values
> > >>>>>> +                     *      ...
> > >>>>>> +                     *      "PrerequisiteSize": 1,
> > >>>>>> +                     *      ...
> > >>>>>> +                     *      "Size": 2,
> > >>>>>> +                     *      ...
> > >>>>>> +                     */
> > >>>>>> +                    if (i == 7)
> > >>>>>> +                            size = pobj->integer.value;
> > >>>>>> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> > >>>>>> 9)
> > >>>>>> +                            size = pobj->integer.value;
> > >>>>>> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> > >>>>>> == 10)
> > >>>>>> +                            size = pobj->integer.value;
> > >>>>>> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> > >>>>>> 11)
> > >>>>>> +                            size = pobj->integer.value;
> > >>>>>> +
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> > >>>>>> %lld,\n", buf,
> > >>>>>> +                                        hp_wmi_elements[type][i], pobj-
> > >>>>>>> integer.value);
> > >>>>>> +            }
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    if (type == HPWMI_ENUMERATION_TYPE) {
> > >>>>>> +            buf_size = snprintf(buf, alloc_size,
> "%s\t\"PossibleValues\":
> > >>>>>> [\n", buf);
> > >>>>>> +            for (i = 0; i < size; i++) {
> > >>>>>> +                    pobj = &(obj->package.elements[i +
> > >>>>>> hp_wmi_elements_count[type]]);
> > >>>>>> +
> > >>>>>> +                    status = convert_hexstr_to_str(&pobj-
> > >>>>>>> string.pointer,
> > >>>>>> +                                                   pobj->string.length,
> > >>>>>> +                                                   &value, &value_len);
> > >>>>>> +                    if (ACPI_FAILURE(status))
> > >>>>>> +                            break;
> > >>>>>> +
> > >>>>>> +                    /*
> > >>>>>> +                     * Report list of "PossibleValues" of size
> > >>>>>> +                     * "Size"
> > >>>>>> +                     *      ...
> > >>>>>> +                     *      "Size": 2,
> > >>>>>> +                     *      "PossibleValues": [
> > >>>>>> +                     *                      "Disable",
> > >>>>>> +                     *                      "Enable"]
> > >>>>>> +                     */
> > >>>>>> +                    if (i == (size - 1))
> > >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> > >>>>>> +                                                "%s\t\t\"%s\"\n", buf,
> > >>>>>> value);
> > >>>>>> +                    else
> > >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> > >>>>>> +                                                "%s\t\t\"%s\",\n", buf,
> > >>>>>> value);
> > >>>>>> +                    kfree(value);
> > >>>>>> +                    value = NULL;
> > >>>>>> +            }
> > >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    if (type == HPWMI_ORDEREDLIST_TYPE) {
> > >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n",
> > >>>>>> buf);
> > >>>>>> +            if (size <= 0)
> > >>>>>> +                    goto finish_ordered_list;
> > >>>>>> +
> > >>>>>> +            pobj = &(obj-
> > >>>>>>> package.elements[hp_wmi_elements_count[type]]);
> > >>>>>> +            status = convert_hexstr_to_str(&pobj->string.pointer,
> > >>>>>> +                                           pobj->string.length, &value,
> > >>>>>> &value_len);
> > >>>>>> +            if (ACPI_FAILURE(status))
> > >>>>>> +                    goto finish_ordered_list;
> > >>>>>> +
> > >>>>>> +            /*
> > >>>>>> +             * Ordered list data is stored in hex and comma separated
> > >>>>>> format
> > >>>>>> +             * Convert the data and split it to show each element
> > >>>>>> +             */
> > >>>>>> +            status = convert_hexstr_to_str(&value, value_len,
> &tmpstr,
> > >>>>>> &tmp_len);
> > >>>>>> +            if (ACPI_FAILURE(status))
> > >>>>>> +                    goto finish_ordered_list;
> > >>>>>> +
> > >>>>>> +            part_tmp = tmpstr;
> > >>>>>> +            part = strsep(&part_tmp, ",");
> > >>>>>> +            while (part) {
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"",
> > >>>>>> buf, part);
> > >>>>>> +                    part = strsep(&part_tmp, ",");
> > >>>>>> +                    if (part)
> > >>>>>> +                            buf_size = snprintf(buf, alloc_size, "%s,\n",
> > >>>>>> buf);
> > >>>>>> +                    else
> > >>>>>> +                            buf_size = snprintf(buf, alloc_size, "%s\n",
> > >>>>>> buf);
> > >>>>>> +            }
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +finish_ordered_list:
> > >>>>>> +    if (type == HPWMI_ORDEREDLIST_TYPE)
> > >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >>>>>> +
> > >>>>>> +    /*
> > >>>>>> +     * remove trailing comma
> > >>>>>> +     */
> > >>>>>> +    if (buf_size > 3)
> > >>>>>> +            buf[buf_size - 2] = ' ';
> > >>>>>> +
> > >>>>>> +    kfree(tmpstr);
> > >>>>>> +    kfree(value);
> > >>>>>> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +static int append_buffer_elements_to_buffer(union acpi_object
> *obj,
> > >>>>>> +                                        char *buf, int alloc_size, enum
> > >>>>>> hp_wmi_data_type type)
> > >>>>>> +{
> > >>>>>> +    int buf_size;
> > >>>>>> +    int status;
> > >>>>>> +    char *str = NULL;
> > >>>>>> +    int i;
> > >>>>>> +    int j;
> > >>>>>> +    int integer;
> > >>>>>> +    int size = 0;
> > >>>>>> +
> > >>>>>> +    if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
> > >>>>>> +            return -EINVAL;
> > >>>>>> +
> > >>>>>> +    if (obj->type != ACPI_TYPE_BUFFER)
> > >>>>>> +            return -EINVAL;
> > >>>>>> +
> > >>>>>> +    buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
> > >>>>>> +    buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n",
> buf,
> > >>>>>> hp_wmi_classes[type]);
> > >>>>>> +
> > >>>>>> +    for (i = 0; i < 3; i++) {
> > >>>>>> +            status = get_string_from_buffer((u16 **)&obj-
> > >>>>>>> buffer.pointer, &str);
> > >>>>>> +            if (ACPI_SUCCESS(status)) {
> > >>>>>> +                    /*
> > >>>>>> +                     * Skip 'Value' (HP_WMI_COMMON_ELEMENTS)
> > >>>>>> since
> > >>>>>> +                     * 'CurrentValue' is reported.
> > >>>>>> +                     */
> > >>>>>> +                    if (type != HPWMI_ENUMERATION_TYPE || i != 1)
> > >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> > >>>>>> +                                                "%s\t\"%s\": \"%s\",\n",
> > >>>>>> +                                                buf,
> > >>>>>> +
> > >>>>>> hp_wmi_elements[type][i], str);
> > >>>>>> +            }
> > >>>>>> +            kfree(str);
> > >>>>>> +            str = NULL;
> > >>>>>> +
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    for (i = 3; i < hp_wmi_elements_count[type]; i++) {
> > >>>>>> +            if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
> > >>>>>> +                    status = get_string_from_buffer((u16 **)&obj-
> > >>>>>>> buffer.pointer, &str);
> > >>>>>> +                    if (ACPI_SUCCESS(status)) {
> > >>>>>> +                            /*
> > >>>>>> +                             * Report "CurrentValue" as "Value"
> > >>>>>> +                             */
> > >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> > >>>>>> +                                                "%s\t\"Value\": \"%s\",\n",
> > >>>>>> buf, str);
> > >>>>>> +                    }
> > >>>>>> +                    kfree(str);
> > >>>>>> +                    str = NULL;
> > >>>>>> +                    continue;
> > >>>>>> +
> > >>>>>> +            } else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
> > >>>>>> +                    /*
> > >>>>>> +                     * Report list of "SupportEncoding"
> > >>>>>> +                     *
> > >>>>>> +                     *      "SupportedEncoding": [
> > >>>>>> +                     *              "utf-16"
> > >>>>>> +                     *      ],
> > >>>>>> +                     *
> > >>>>>> +                     */
> > >>>>>> +
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
> > >>>>>> +                                        buf, hp_wmi_elements[type][i]);
> > >>>>>> +                    for (j = 0; j < size; j++) {
> > >>>>>> +                            status = get_string_from_buffer((u16
> > >>>>>> **)&obj->buffer.pointer, &str);
> > >>>>>> +                            if (ACPI_SUCCESS(status)) {
> > >>>>>> +                                    if (j == size - 1)
> > >>>>>> +                                            buf_size = snprintf(buf,
> > >>>>>> alloc_size,
> > >>>>>> +
> > >>>>>> "%s\t\t\"%s\"\n", buf, str);
> > >>>>>> +                                    else
> > >>>>>> +                                            buf_size = snprintf(buf,
> > >>>>>> alloc_size,
> > >>>>>> +
> > >>>>>> "%s\t\t\"%s\",\n", buf, str);
> > >>>>>> +                            }
> > >>>>>> +                            kfree(str);
> > >>>>>> +                            str = NULL;
> > >>>>>> +                    }
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >>>>>> +                    continue;
> > >>>>>> +            }
> > >>>>>> +
> > >>>>>> +            size = 0;
> > >>>>>> +            status = get_integer_from_buffer((int **)&obj-
> > >>>>>>> buffer.pointer, &integer);
> > >>>>>> +            if (ACPI_SUCCESS(status)) {
> > >>>>>> +                    /*
> > >>>>>> +                     * Report "PrerequisiteSize" and "Size" values
> > >>>>>> +                     *      ...
> > >>>>>> +                     *      "PrerequisiteSize": 1,
> > >>>>>> +                     *      ...
> > >>>>>> +                     *      "Size": 2,
> > >>>>>> +                     *      ...
> > >>>>>> +                     */
> > >>>>>> +                    if (i == 7)
> > >>>>>> +                            size = integer;
> > >>>>>> +                    else if (type == HPWMI_ENUMERATION_TYPE && i
> > >>>>>> == 10)
> > >>>>>> +                            size = integer;
> > >>>>>> +                    else if (type == HPWMI_ORDEREDLIST_TYPE && i ==
> > >>>>>> 9)
> > >>>>>> +                            size = integer;
> > >>>>>> +                    else if (type == HPWMI_PASSWORD_TYPE && i ==
> > >>>>>> 11)
> > >>>>>> +                            size = integer;
> > >>>>>> +
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t\"%s\":
> > >>>>>> %d,\n", buf,
> > >>>>>> +                                        hp_wmi_elements[type][i],
> > >>>>>> integer);
> > >>>>>> +            }
> > >>>>>> +
> > >>>>>> +            if (size > 20)
> > >>>>>> +                    pr_warn("%s exceeded the maximum number of
> > >>>>>> elements supported or data may be malformed\n",
> > >>>>>> +                            hp_wmi_elements[type][i]);
> > >>>>>> +
> > >>>>>> +            if (ACPI_SUCCESS(status) && i == 7) {
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> "%s\t\"Prerequisites\": [\n", buf);
> > >>>>>> +                    for (j = 0; j < size; j++) {
> > >>>>>> +                            status = get_string_from_buffer((u16
> > >>>>>> **)&obj->buffer.pointer, &str);
> > >>>>>> +                            if (ACPI_SUCCESS(status)) {
> > >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> "%s\t\t\"%s\"", buf, str);
> > >>>>>> +
> > >>>>>> +                                    if (j == size - 1)
> > >>>>>> +                                            buf_size = snprintf(buf,
> > >>>>>> alloc_size, "%s\n", buf);
> > >>>>>> +                                    else
> > >>>>>> +                                            buf_size = snprintf(buf,
> > >>>>>> alloc_size, "%s,\n", buf);
> > >>>>>> +
> > >>>>>> +                            }
> > >>>>>> +                            kfree(str);
> > >>>>>> +                            str = NULL;
> > >>>>>> +                    }
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >>>>>> +            }
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    if (type == HPWMI_ENUMERATION_TYPE || type ==
> > >>>>>> HPWMI_ORDEREDLIST_TYPE) {
> > >>>>>> +            if (type == HPWMI_ENUMERATION_TYPE)
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> "%s\t\"PossibleValues\": [\n", buf);
> > >>>>>> +            else
> > >>>>>> +                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> "%s\t\"Elements\": [\n", buf);
> > >>>>>> +
> > >>>>>> +            for (i = 0; i < size; i++) {
> > >>>>>> +                    status = get_string_from_buffer((u16 **)&obj-
> > >>>>>>> buffer.pointer, &str);
> > >>>>>> +                    if (ACPI_SUCCESS(status)) {
> > >>>>>> +                            buf_size = snprintf(buf, alloc_size,
> > >>>>>> "%s\t\t\"%s\"", buf, str);
> > >>>>>> +
> > >>>>>> +                            if (i == size - 1)
> > >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> "%s\n", buf);
> > >>>>>> +                            else
> > >>>>>> +                                    buf_size = snprintf(buf, alloc_size,
> > >>>>>> "%s,\n", buf);
> > >>>>>> +
> > >>>>>> +                    }
> > >>>>>> +                    kfree(str);
> > >>>>>> +                    str = NULL;
> > >>>>>> +            }
> > >>>>>> +            buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    /*
> > >>>>>> +     * remove trailing comma
> > >>>>>> +     */
> > >>>>>> +    if (buf_size > 3)
> > >>>>>> +            buf[buf_size - 2] = ' ';
> > >>>>>> +
> > >>>>>> +    return snprintf(buf, alloc_size, "%s},\n", buf);
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +static int hp_bios_settings_free_buffer(void)
> > >>>>>> +{
> > >>>>>> +    mutex_lock(&buf_mutex);
> > >>>>>> +    kfree(hp_bios_settings_buffer);
> > >>>>>> +    settings_buffer_size = 0;
> > >>>>>> +    buf_alloc_size = 0;
> > >>>>>> +    mutex_unlock(&buf_mutex);
> > >>>>>> +
> > >>>>>> +    return 0;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +static int hp_bios_settings_realloc_buffer(char **buf, int
> *buf_size,
> > >>>>>> +                                       int *alloc_size,
> > >>>>>> +                                       struct mutex *buf_mutex)
> > >>>>>> +{
> > >>>>>> +    int new_buffer_size;
> > >>>>>> +    char *new_buf = NULL;
> > >>>>>> +    int ret = 0;
> > >>>>>> +
> > >>>>>> +    if (*buf_size + PAGE_SIZE >= *alloc_size) {
> > >>>>>> +            new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
> > >>>>>> +
> > >>>>>> +            mutex_lock(buf_mutex);
> > >>>>>> +            new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
> > >>>>>> +            mutex_unlock(buf_mutex);
> > >>>>>> +            if (new_buf) {
> > >>>>>> +                    mutex_lock(buf_mutex);
> > >>>>>> +                    *buf = new_buf;
> > >>>>>> +                    *alloc_size = ksize(new_buf);
> > >>>>>> +                    mutex_unlock(buf_mutex);
> > >>>>>> +            } else {
> > >>>>>> +                    hp_bios_settings_free_buffer();
> > >>>>>> +                    ret = -ENOMEM;
> > >>>>>> +            }
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    return ret;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +static int append_settings_to_buffer(char *guid, int type, char
> **buf,
> > >>>>>> +                                 int *buf_size, int *alloc_size,
> > >>>>>> +                                 struct mutex *buf_mutex)
> > >>>>>> +{
> > >>>>>> +    union acpi_object *obj = NULL;
> > >>>>>> +    int ret = 0;
> > >>>>>> +    int status = 0;
> > >>>>>> +    int instance = 0;
> > >>>>>> +
> > >>>>>> +    /*
> > >>>>>> +     * Query all the instances until to receive a
> AE_BAD_PARAMETER
> > >>>>>> +     */
> > >>>>>> +    do {
> > >>>>>> +            ret = hp_wmi_get_setting_object(guid, instance++, &obj);
> > >>>>>> +            if (ACPI_SUCCESS(ret) && obj != NULL) {
> > >>>>>> +                    status = 0;
> > >>>>>> +                    if (obj->type == ACPI_TYPE_PACKAGE) {
> > >>>>>> +                            mutex_lock(buf_mutex);
> > >>>>>> +                            status =
> > >>>>>> append_package_elements_to_buffer(obj,
> > >>>>>> +                                                    *buf, *alloc_size,
> > >>>>>> type);
> > >>>>>> +                            if (status > 0)
> > >>>>>> +                                    *buf_size = status;
> > >>>>>> +                            mutex_unlock(buf_mutex);
> > >>>>>> +
> > >>>>>> +                    } else if (obj->type == ACPI_TYPE_BUFFER) {
> > >>>>>> +                            mutex_lock(buf_mutex);
> > >>>>>> +                            status =
> > >>>>>> append_buffer_elements_to_buffer(obj,
> > >>>>>> +                                                    *buf, *alloc_size,
> > >>>>>> type);
> > >>>>>> +                            if (status > 0)
> > >>>>>> +                                    *buf_size = status;
> > >>>>>> +                            mutex_unlock(buf_mutex);
> > >>>>>> +
> > >>>>>> +                    } else
> > >>>>>> +                            pr_warn("The retrieved object type(%d) is
> > >>>>>> not supported yet\n",
> > >>>>>> +                                    obj->type);
> > >>>>>> +
> > >>>>>> +                    ret = hp_bios_settings_realloc_buffer(buf, buf_size,
> > >>>>>> alloc_size, buf_mutex);
> > >>>>>> +            }
> > >>>>>> +
> > >>>>>> +            kfree(obj);
> > >>>>>> +            obj = NULL;
> > >>>>>> +
> > >>>>>> +    } while (ACPI_SUCCESS(ret));
> > >>>>>> +
> > >>>>>> +    /*
> > >>>>>> +     * AE_BAD_PARAMETER means the loop ended by exhaustion
> > >>>>>> +     */
> > >>>>>> +    if (ret == AE_BAD_PARAMETER)
> > >>>>>> +            ret = 0;
> > >>>>>> +
> > >>>>>> +    return ret;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +static int hp_bios_settings_fill_buffer(void)
> > >>>>>> +{
> > >>>>>> +    int status = 0;
> > >>>>>> +    int initial_buffer_size = 20 * PAGE_SIZE;
> > >>>>>> +
> > >>>>>> +    mutex_lock(&buf_mutex);
> > >>>>>> +    hp_bios_settings_buffer = kmalloc(initial_buffer_size,
> > >>> GFP_KERNEL);
> > >>>>>> +    mutex_unlock(&buf_mutex);
> > >>>>>> +    if (!hp_bios_settings_buffer)
> > >>>>>> +            return -ENOMEM;
> > >>>>>> +
> > >>>>>> +    mutex_lock(&buf_mutex);
> > >>>>>> +    buf_alloc_size = ksize(hp_bios_settings_buffer);
> > >>>>>> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> > >>>>>> +                                    buf_alloc_size, "[\n");
> > >>>>>> +    mutex_unlock(&buf_mutex);
> > >>>>>> +
> > >>>>>> +    status = append_settings_to_buffer(HPWMI_STRING_GUID,
> > >>>>>> +            HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
> > >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >>>>>> +    if (ACPI_FAILURE(status))
> > >>>>>> +            pr_err("error 0x%x occurred retrieving string instances\n",
> > >>>>>> status);
> > >>>>>> +
> > >>>>>> +    status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
> > >>>>>> +            HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
> > >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >>>>>> +    if (ACPI_FAILURE(status))
> > >>>>>> +            pr_err("error 0x%x occurred retrieving integer
> instances\n",
> > >>>>>> status);
> > >>>>>> +
> > >>>>>> +    status =
> > >>> append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
> > >>>>>> +            HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
> > >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >>>>>> +    if (ACPI_FAILURE(status))
> > >>>>>> +            pr_err("error 0x%x occurred retrieving enumeration
> > >>>>>> instances\n", status);
> > >>>>>> +
> > >>>>>> +    status =
> append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
> > >>>>>> +            HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
> > >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >>>>>> +    if (ACPI_FAILURE(status))
> > >>>>>> +            pr_err("error 0x%x occurred retrieving ordered list
> > >>>>>> instances\n", status);
> > >>>>>> +
> > >>>>>> +    status =
> append_settings_to_buffer(HPWMI_PASSWORD_GUID,
> > >>>>>> +            HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
> > >>>>>> +            &settings_buffer_size, &buf_alloc_size, &buf_mutex);
> > >>>>>> +    if (ACPI_FAILURE(status))
> > >>>>>> +            pr_err("error 0x%x occurred retrieving password list
> > >>>>>> instances\n", status);
> > >>>>>> +
> > >>>>>> +    mutex_lock(&buf_mutex);
> > >>>>>> +    /*
> > >>>>>> +     * remove trailing comma
> > >>>>>> +     */
> > >>>>>> +    if (settings_buffer_size >= 3) {
> > >>>>>> +            if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
> > >>>>>> +                    hp_bios_settings_buffer[settings_buffer_size - 2] = '
> > >>>>>> ';
> > >>>>>> +    }
> > >>>>>> +    settings_buffer_size = snprintf(hp_bios_settings_buffer,
> > >>>>>> +                                    buf_alloc_size, "%s]\n",
> > >>>>>> +                                    hp_bios_settings_buffer);
> > >>>>>> +    mutex_unlock(&buf_mutex);
> > >>>>>> +
> > >>>>>> +    return settings_buffer_size;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +/*
> > >>>>>> + * sure_admin_settings_read - Return a formatted file with
> settings
> > >>>>>> + *                              and possible options read from BIOS
> > >>>>>> + *
> > >>>>>> + * @filp:  Pointer to file of settings read from BIOS
> > >>>>>> + * @kobj:  Pointer to a kernel object of things that show up as
> directory
> > >>> in
> > >>>>>> the sysfs filesystem.
> > >>>>>> + * @attr:  Pointer to list of read attributes
> > >>>>>> + * @buf:   Pointer to buffer
> > >>>>>> + * @off:   File current offset
> > >>>>>> + * @count: Buffer size
> > >>>>>> + *
> > >>>>>> + * Returns the count of unicode chars read if successful,
> otherwise
> > >>>>>> + *          -ENOMEM unable to allocate memory
> > >>>>>> + *          -EINVAL buffer not allocated or too small
> > >>>>>> + *
> > >>>>>> + */
> > >>>>>> +static ssize_t sure_admin_settings_read(struct file *filp, struct
> kobject
> > >>>>>> *kobj,
> > >>>>>> +                                    struct bin_attribute *attr, char *buf,
> > >>>>>> loff_t off, size_t count)
> > >>>>>> +{
> > >>>>>> +    ssize_t ret;
> > >>>>>> +
> > >>>>>> +    /* clear the buffer when offset is pointing to the last position */
> > >>>>>> +    if (off >= settings_buffer_size && settings_buffer_size > 0) {
> > >>>>>> +            hp_bios_settings_free_buffer();
> > >>>>>> +            return 0;
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    /* clear the buffer whenever the read starts from the first
> position
> > >>>>>> */
> > >>>>>> +    if (off == 0 && settings_buffer_size > 0)
> > >>>>>> +            hp_bios_settings_free_buffer();
> > >>>>>> +
> > >>>>>> +    if (settings_buffer_size == 0)
> > >>>>>> +            hp_bios_settings_fill_buffer();
> > >>>>>> +
> > >>>>>> +    mutex_lock(&buf_mutex);
> > >>>>>> +    ret = memory_read_from_buffer(buf, count, &off,
> > >>>>>> hp_bios_settings_buffer,
> > >>>>>> +                                  settings_buffer_size);
> > >>>>>> +    mutex_unlock(&buf_mutex);
> > >>>>>> +
> > >>>>>> +    return ret;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +
> > >>>>>> +/*
> > >>>>>> + * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
> > >>>>>> + *
> > >>>>>> + * @p:   Unicode buffer address
> > >>>>>> + * @str: string to convert to unicode
> > >>>>>> + *
> > >>>>>> + * Returns a void pointer to the buffer containing unicode string
> > >>>>>> + */
> > >>>>>> +static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
> > >>>>>> +{
> > >>>>>> +    int len = strlen(str);
> > >>>>>> +
> > >>>>>> +    /*
> > >>>>>> +     * Add null character when reading an empty string
> > >>>>>> +     */
> > >>>>>> +    if (len == 0) {
> > >>>>>> +            *p++ = 2;
> > >>>>>> +            *p++ = (u8)0x00;
> > >>>>>> +            return p;
> > >>>>>> +    }
> > >>>>>> +    *p++ = len * 2;
> > >>>>>> +    utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
> > >>>>>> +    p += len;
> > >>>>>> +
> > >>>>>> +    return p;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +/*
> > >>>>>> + * hp_wmi_set_bios_setting - Set setting's value in BIOS
> > >>>>>> + *
> > >>>>>> + * @input_buffer: Input buffer address
> > >>>>>> + * @input_size:   Input buffer size
> > >>>>>> + *
> > >>>>>> + * Returns: Count of unicode characters written to BIOS if
> successful,
> > >>>>>> otherwise
> > >>>>>> + *          -ENOMEM unable to allocate memory
> > >>>>>> + *          -EINVAL buffer not allocated or too small
> > >>>>>> + */
> > >>>>>> +static int hp_wmi_set_bios_setting(u16 *input_buffer, u32
> input_size)
> > >>>>>> +{
> > >>>>>> +    union acpi_object *obj;
> > >>>>>> +    struct acpi_buffer input = {input_size, input_buffer};
> > >>>>>> +    struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
> > >>>>>> +    int ret = 0;
> > >>>>>> +
> > >>>>>> +    ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID,
> 0, 1,
> > >>>>>> &input, &output);
> > >>>>>> +
> > >>>>>> +    obj = output.pointer;
> > >>>>>> +    if (!obj)
> > >>>>>> +            return -EINVAL;
> > >>>>>> +
> > >>>>>> +    if (obj->type != ACPI_TYPE_INTEGER)
> > >>>>>> +            ret = -EINVAL;
> > >>>>>> +
> > >>>>>> +    ret = obj->integer.value;
> > >>>>>> +    kfree(obj);
> > >>>>>> +    return ret;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +/* Sure Admin Functions */
> > >>>>>> +
> > >>>>>> +#define UTF_PREFIX                  ((unsigned char *)"<utf-16/>")
> > >>>>>> +#define BEAM_PREFIX                 ((unsigned char
> > >>>>>> *)"<BEAM/>")
> > >>>>>> +
> > >>>>>> +/*
> > >>>>>> + * sure_admin_settings_write - Write the contents of a
> formatted file
> > >>>>>> + *                               with settings and performs the logic
> > >>>>>> + *                               to change any settings in BIOS.
> > >>>>>> + *
> > >>>>>> + * @filp:  Pointer to file of settings to be written to BIOS
> > >>>>>> + * @kobj:  Pointer to a kernel object of things that show up as
> directory
> > >>> in
> > >>>>>> the sysfs filesystem.
> > >>>>>> + * @attr:  Pointer to list of attributes for the write operation
> > >>>>>> + * @buf:   Pointer to buffer
> > >>>>>> + * @off:   File current offset
> > >>>>>> + * @count: Buffer size
> > >>>>>> + *
> > >>>>>> + *
> > >>>>>> + * Returns the count of unicode characters written to BIOS if
> > >>> successful,
> > >>>>>> otherwise
> > >>>>>> + *          -ENOMEM unable to allocate memory
> > >>>>>> + *          -EINVAL buffer not allocated or too small
> > >>>>>> + *
> > >>>>>> + */
> > >>>>>> +static ssize_t sure_admin_settings_write(struct file *filp, struct
> kobject
> > >>>>>> *kobj,
> > >>>>>> +                    struct bin_attribute *attr, char *buf, loff_t off, size_t
> > >>>>>> count)
> > >>>>>> +{
> > >>>>>> +    int status = 0;
> > >>>>>> +    char *part = NULL;
> > >>>>>> +    int part_len = 0;
> > >>>>>> +    unsigned short *buffer = NULL;
> > >>>>>> +    unsigned short *tmpstr = NULL;
> > >>>>>> +    int buffer_size = (count + strlen(UTF_PREFIX)) *
> sizeof(unsigned
> > >>>>>> short);
> > >>>>>> +
> > >>>>>> +    buffer = kmalloc(buffer_size, GFP_KERNEL);
> > >>>>>> +    if (!buffer)
> > >>>>>> +            return -ENOMEM;
> > >>>>>> +
> > >>>>>> +    tmpstr = buffer;
> > >>>>>> +    part = strsep(&buf, ",");
> > >>>>>> +    if (!part) {
> > >>>>>> +            status = -EINVAL;
> > >>>>>> +            goto out_free;
> > >>>>>> +    }
> > >>>>>> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > >>>>>> +    part = strsep(&buf, ",");
> > >>>>>> +    if (!part) {
> > >>>>>> +            status = -EINVAL;
> > >>>>>> +            goto out_free;
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    /* Add extra buffer space when encountering an empty string
> */
> > >>>>>> +    if (!strlen(part))
> > >>>>>> +            buffer_size += sizeof(unsigned short);
> > >>>>>> +    tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > >>>>>> +    part = strsep(&buf, ",");
> > >>>>>> +    if (!part) {
> > >>>>>> +            status = -EINVAL;
> > >>>>>> +            goto out_free;
> > >>>>>> +    }
> > >>>>>> +    part_len = strlen(part) - 1;
> > >>>>>> +    part[part_len] = '\0';
> > >>>>>> +
> > >>>>>> +    if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
> > >>>>>> +           /*
> > >>>>>> +            * BEAM_PREFIX is append to buffer when a signature
> > >>>>>> +            * is provided and Sure Admin is enabled in BIOS
> > >>>>>> +            */
> > >>>>>> +            // BEAM_PREFIX found, convert part to unicode
> > >>>>>> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > >>>>>> +            // decrease buffer size allocated initially for UTF_PREFIX
> > >>>>>> +            buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
> > >>>>>> +    } else {
> > >>>>>> +            /*
> > >>>>>> +             * UTF-16 prefix is append to the * buffer when a BIOS
> > >>>>>> +             * admin password is configured in BIOS
> > >>>>>> +             */
> > >>>>>> +
> > >>>>>> +            // append UTF_PREFIX to part and then convert it to
> unicode
> > >>>>>> +            part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
> > >>>>>> +            if (!part)
> > >>>>>> +                    goto out_free;
> > >>>>>> +
> > >>>>>> +            tmpstr = ascii_to_utf16_unicode(tmpstr, part);
> > >>>>>> +            kfree(part);
> > >>>>>> +    }
> > >>>>>> +
> > >>>>>> +    part = strsep(&buf, ",");
> > >>>>>> +    if (part) {
> > >>>>>> +            status = -EINVAL;
> > >>>>>> +            goto out_free;
> > >>>>>> +    }
> > >>>>>> +    status = hp_wmi_set_bios_setting(buffer, buffer_size);
> > >>>>>> +    if (ACPI_FAILURE(status))
> > >>>>>> +            status = -EINVAL;
> > >>>>>> +
> > >>>>>> +out_free:
> > >>>>>> +    kfree(buffer);
> > >>>>>> +    if (ACPI_SUCCESS(status))
> > >>>>>> +            return count;
> > >>>>>> +    return status;
> > >>>>>> +}
> > >>>>>> +
> > >>>>>> +HPWMI_BINATTR_RW(sure_admin, settings, 0);
> > >>>>>> +
> > >>>>>> +static struct bin_attribute *sure_admin_binattrs[] = {
> > >>>>>> +    &sure_admin_settings,
> > >>>>>> +    NULL,
> > >>>>>> +};
> > >>>>>> +
> > >>>>>> +static const struct attribute_group sure_admin_group = {
> > >>>>>> +    .name = "sure_admin",
> > >>>>>> +    .bin_attrs = sure_admin_binattrs,
> > >>>>>> +};
> > >>>>>> +
> > >>>>>>  static DEVICE_ATTR_RO(display);
> > >>>>>>  static DEVICE_ATTR_RO(hddtemp);
> > >>>>>>  static DEVICE_ATTR_RW(als);
> > >>>>>> @@ -1050,6 +2026,7 @@ static const struct attribute_group
> > >>>>>> *hp_wmi_groups[] = {
> > >>>>>>      &hp_wmi_group,
> > >>>>>>      &spm_group,
> > >>>>>>      &sure_start_group,
> > >>>>>> +    &sure_admin_group,
> > >>>>>>      NULL,
> > >>>>>>  };
> > >>>>>>
> > >>>>>> --
> > >>>>>> 2.25.1
> > >>>>
> > >
> >

Hans de Goede April 8, 2022, 3:04 p.m. UTC | #11

Hi,

On 4/8/22 16:54, Limonciello, Mario wrote:
> [Public]
> 
> 
> 
>> -----Original Message-----
>> From: Jorge Lopez <[e-mail]>
>> Sent: Friday, April 8, 2022 09:47
>> To: Hans de Goede <[e-mail]>
>> Cc: Limonciello, Mario <[e-mail]>; platform-driver-
>> [e-mail]
>> Subject: Re: [PATCH v1 5/6] Sure Admin Security Feature
>>
>> On Fri, Apr 8, 2022 at 4:21 AM Hans de Goede <[e-mail]>
>> wrote:
>>>
>>> Hi Jorge,
>>>
>>> On 4/7/22 15:44, Jorge Lopez wrote:
>>>> Hans, Mario,
>>>>
>>>> The code links make references to code that implements the new
>>>> interfaces but there's
>>>> still code in the kernel that uses the old ones.
>>>
>>> I'm not sure what you mean with "uses the old ones" there never
>>> has been any kernel drivers for changing BIOS settings before
>>> the dell and lenovo drivers were merged.
>>
>> "uses the old ones" statement means that there are drivers on the tree
>> that change BIOS settings without having to convert to the new
>> standards.  hp-wmi remained unsupported for many years so I can
>> understand why the security features need to use the standardized API.
>>
>>>
>>> Sure there are generic mechanisms like chardev-s and ioctls which
>>> are used for a whole bunch of things. But AFAIK there never was
>>> an API specifically for changing BIOS settings before.
>>>
>>>> I do agree we should
>>>> be forward looking
>>>> and want to be good participants in the kernel development, but can't
>>>> let our immediate
>>>> business needs be impacted with opportunities to enhance the driver to
>>>> take advantage
>>>> of the latest kernel features.
>>>>
>>>> Rewriting those security features will impact customer business
>>>> datelines requiring
>>>> HP to provide private releases as the kernel version changes.   The
>>>> requested changes
>>>> will impact products in the market and HP ability to help customers to
>>>> migrate to Linux
>>>> from Windows products.
>>>
>>> This sounds like you are saying that you are already shipping
>>> a version of the driver with the non-standard API to customers.
>>> Shipping code to customers before even proposing it upstream is
>>> HP own choice and the results of that as such are HP's
>>> responsibility.
>>>
>> The products shipped to customers are Windows products and customers
>> are accustomed to how the data is reported and set.  The goal for the
>> new security features in Linux is to help those customers migrate to
>> Linux with little or no change to their scripts/tools.
> 
> I think if this is the situation then a userspace compatibility /conversion tool is
> your better answer than a large compatibility layer in debugfs.
> 
> From the customer perspective they just need to see that JSON file in/out, right?
> So you should be able to write a tool/script that parses all the attributes from
> sysfs in a high level language and puts them into a JSON payload for their scripts
> to work from.  Likewise it should be able to parse a JSON payload and deploy
> all of that stuff into the standard API.

Big +1 from me for this proposal, I agree that having some userspace tool
to work with Windows compatible json files would be best here.


> 
> You can also explain in your documentation associates with such a tool/script
> that it's using a standard API and if they want to use that API directly instead
> of your compatibility tool they're welcome to do so.
> 
>>
>>> You cannot just say we are already shipping this so we need
>>> the upstream kernel to support this non standard API, that is
>>> not how upstream kernel development works.
>>>
>>> I realize that HP is new to working directly with the upstream kernel
>>> community and I realize that being told that the API which you are
>>> already using cannot be used for upstreaming your driver is not what
>>> you want to hear.
>>>
>>> But that does not change that I cannot accept a driver which does not
>>> implement the standard API which the upstream kernel community has
>>> agreed upon for this functionality.
>>>
>>> Or as Mario very elegantly put it:
>>>
>>> 'Keep in mind that from an upstream kernel perspective this driver is
>> "new".
>>> There is no requirements from the upstream perspective to
>>> keep your old interfaces in place from when it was out of tree.'
>>>
>>>> It is because of the immediate business needs, avoiding impacting our
>>>> customers/products,
>>>> and rewriting  enhancements to the driver that I need to propose an
>>>> interim solution.
>>>>
>>>> My proposal is to introduce a read/write value accessible in the user
>>>> space to control how
>>>> the driver reports and handles BIOS settings and values.  The new
>>>> configuration features
>>>> will be gradually disabled  as they are converted to use the standardized
>> API.
>>>> It is like the configuration flag used to overcome the tablet detection
>> problem
>>>> introduced in the past.   The changes solely affect the HP WMI driver.
>>>> This option will help us
>>>> move forward for this release and give us time to make the necessary
>>>> changes to both
>>>> the driver and support applications.
>>>>
>>>> Please let me know if this is a viable interim solution.
>>>
>>> First of all to be very clear, any code going upstream must support
>>> the standard API:
>>>
>>>
>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
>> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%
>> 2Ftree%2FDocumentation%2FABI%2Ftesting%2Fsysfs-class-firmware-
>> attributes&amp;data=04%7C01%7CMario.Limonciello%40amd.com%7Cb0dd9
>> 6dde69d48c4e60c08da196ea2e1%7C3dd8961fe4884e608e11a82d994e183d%7
>> C0%7C0%7C637850260243195656%7CUnknown%7CTWFpbGZsb3d8eyJWIjoi
>> MC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C300
>> 0&amp;sdata=HDIa3CmOAhty7ZtwAoKh5VveEGCC%2Fuq5E1rx0hWOHns%3
>> D&amp;reserved=0
>>>
>>> from day one. I'm not really enthusiastic about the concept of also
>>> supporting the API which you have been using out of tree so far, but
>>> I guess that Mario's suggestion to offer a Kconfig option which
>>> when enabled offers this API under debugfs might be an acceptible
>>> compromise. I would need to see the actual code for that though to
>>> see if this is acceptable.
>>>
>>> And there would need to be a clear cut-of date document after which
>>> the code to support the old API will be removed.
>>>
>>>> If it is not possible, I need to ask where the actual written
>>>> requirement is found so I can
>>>> include them in the business justification for changes and release
>>>> delays to management.
>>>
>>> I'm not sure if this is written down somewhere, but certainly
>>> you will agree that if you were submitting a driver for a soundcard
>>> that that should use the existing ALSA userspace API for sound so
>>> that it would just work with the existing userspace sound support.
>>>
>>> This is the same. If an existing standardized userspace API exists
>>> for a certain functionality then that userspace API _must_ be used,
>>> AFAIK this is not explictly written down anywhere because it is just
>>> very much common sense.
>>
>> I completely agree with your comments and request for the driver to
>> implement the standardized API.  hp-wmi remained unsupported for many
>> years so I can understand why the security features need to use the
>> standardized API.  I am having conversations with other teams on how
>> to move forward with the standard API and how the data is handled and
>> reported.   We will submit a new set of patches utilizing the new
>> standard at a later time.   Would it be accurate to state that any
>> extensions to the standardized API model are acceptable, Correct?
>>
> 
> That's correct.  Dell did the first driver, and then Lenovo did the second.
> The majority of the features from the Dell driver applied to the Lenovo one
> and any idiosyncrasies were introduced as new sysfs files or documented and
> agreed different behaviors of others.

Again +1 / I agree where possible please try to fit things in the standardized
API, but as you can see from both the Dell and Lenovo sections in the API docs,
vendor extensions are allowed.

Regards,

Hans

Patch

diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
index 918e3eaf1b67..b72ca18b77a6 100644
--- a/drivers/platform/x86/hp-wmi.c
+++ b/drivers/platform/x86/hp-wmi.c
@@ -27,6 +27,7 @@ 
 #include <linux/rfkill.h>
 #include <linux/string.h>
 #include <linux/dmi.h>
+#include <linux/nls.h>
 
 MODULE_AUTHOR("Matthew Garrett <[e-mail]>");
 MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
@@ -37,8 +38,16 @@  MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-3D44E2C707E4");
 
 #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-ACCDC67EF61C"
 #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-3D44E2C707E4"
+
 #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
 
+#define HPWMI_STRING_GUID "988D08E3-68F4-4c35-AF3E-6A1B8106F83C"
+#define HPWMI_INTEGER_GUID "8232DE3D-663D-4327-A8F4-E293ADB9BF05"
+#define HPWMI_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-4A3C09E75133"
+#define HPWMI_ORDEREDLIST_GUID "14EA9746-CE1F-4098-A0E0-7045CB4DA745"
+#define HPWMI_PASSWORD_GUID "322F2028-0F84-4901-988E-015176049E2D"
+#define HPWMI_SETBIOSSETTING_GUID "1F4C91EB-DC5C-460b-951D-C7CB9B4B8D5E"
+
 /* DMI board names of devices that should use the omen specific path for
  * thermal profiles.
  * This was obtained by taking a look in the windows omen command center
@@ -1025,6 +1034,973 @@  static const struct attribute_group sure_start_group = {
 	.attrs = sure_start_attrs,
 };
 
+
+static int convert_hexstr_to_str(char **hex, int input_len, char **str, int *len)
+{
+	int ret = 0;
+	int new_len = 0;
+	char tmp[] = "0x00";
+	char *input = *hex;
+	char *new_str = NULL;
+	int  ch;
+	int i;
+
+	if (input_len <= 0 || hex == NULL || str == NULL || len == NULL)
+		return -EINVAL;
+
+	*len = 0;
+	*str = NULL;
+
+	new_str = kmalloc(input_len, GFP_KERNEL);
+	if (!new_str)
+		return -ENOMEM;
+
+	for (i = 0; i < input_len; i += 5) {
+		strncpy(tmp, input + i, strlen(tmp));
+		ret = kstrtoint(tmp, 16, &ch);
+		if (ret) {
+			new_len = 0;
+			break;
+		}
+
+		if (ch == '\\')
+			new_str[new_len++] = '\\';
+
+		new_str[new_len++] = ch;
+		if (ch == '\0')
+			break;
+	}
+
+	if (new_len) {
+		new_str[new_len] = '\0';
+		*str = krealloc(new_str, (new_len + 1) * sizeof(char), GFP_KERNEL);
+		if (*str)
+			*len = new_len;
+		else
+			ret = -ENOMEM;
+	}
+
+	if (ret)
+		kfree(new_str);
+	return ret;
+}
+
+/*
+ * hp_wmi_get_setting_object() - Get an ACPI object by GUID and instance
+ *
+ * @guid:	GUID associated with the ACPI list of managed objects
+ * @instance:	Instance index to query on the ACPI list
+ * @obj:	The output ACPI object of type ACPI_TYPE_PACKAGE
+ *		or ACPI_TYPE_BUFFER (freed by the callee)
+ *
+ * Returns	zero on success.  Otherwise,an error inherited from
+ *		wmi_query_block(). It returns a obj by parameter if
+ *		the query returned object of type buffer or package,
+ *		otherwise, a null obj is returned.
+ *
+ * Note: obj should be freed by the callee once it is finished working with it
+ */
+static int hp_wmi_get_setting_object(char *guid, int instance,
+				union acpi_object **obj)
+{
+	struct acpi_buffer output = { ACPI_ALLOCATE_LOCAL_BUFFER, NULL };
+	union acpi_object *tmp = NULL;
+	int ret;
+
+	ret = wmi_query_block(guid, instance, &output);
+	if (ACPI_SUCCESS(ret) && output.pointer != NULL) {
+		tmp = output.pointer;
+		if (tmp->type == ACPI_TYPE_BUFFER || tmp->type == ACPI_TYPE_PACKAGE)
+			*obj = output.pointer;
+		else {
+			kfree(tmp);
+			*obj = NULL;
+		}
+	}
+
+	return ret;
+}
+
+
+static int get_string_from_buffer(u16 **buffer, char **str)
+{
+	u16 *ptr = *buffer;
+	u16 ptrlen;
+
+	u16 size;
+	int i;
+	char *output = NULL;
+	int escape = 0;
+
+	ptrlen = *(ptr++);
+	size = ptrlen / 2;
+
+	if (size == 0)
+		goto cleanup_exit;
+
+	for (i = 0; i < size; i++)
+		if (ptr[i] == '\\')
+			escape++;
+
+	size += escape;
+	*str = kcalloc(size + 1, sizeof(char), GFP_KERNEL);
+	if (!*str)
+		return -ENOMEM;
+
+	output = *str;
+
+	/*
+	 * convert from UTF-16 unicode to ASCII
+	 */
+	utf16s_to_utf8s(ptr, ptrlen, UTF16_HOST_ENDIAN, output, size);
+
+	if (escape == 0) {
+		ptr += (ptrlen / 2);
+		goto cleanup_exit;
+	}
+	/*
+	 * Convert escape characters only when found
+	 */
+	for (i = 0; i < size; i++) {
+		if (*ptr == '\\')
+			output[i++] = '\\';
+		output[i] = *ptr;
+		ptr++;
+	}
+
+cleanup_exit:
+	*buffer = ptr;
+	return 0;
+}
+
+static int get_integer_from_buffer(int **buffer, int *integer)
+{
+	int *ptr = PTR_ALIGN(*buffer, 4);
+	*integer = *(ptr++);
+	*buffer = ptr;
+	return 0;
+}
+
+
+// Sure Admin functions
+enum hp_wmi_data_type {
+	HPWMI_STRING_TYPE,
+	HPWMI_INTEGER_TYPE,
+	HPWMI_ENUMERATION_TYPE,
+	HPWMI_ORDEREDLIST_TYPE,
+	HPWMI_PASSWORD_TYPE,
+};
+
+#define HP_WMI_COMMON_ELEMENTS	\
+	"Name",	\
+	"Value",	\
+	"Path",	\
+	"IsReadOnly",	\
+	"DisplayInUI",	\
+	"RequiresPhysicalPresence",	\
+	"Sequence",	\
+	"PrerequisiteSize",	\
+	"SecurityLevel"
+
+const char *hp_wmi_string_elements[] = {
+	HP_WMI_COMMON_ELEMENTS,
+	"MinLength",
+	"MaxLength"
+};
+
+const char *hp_wmi_integer_elements[] = {
+	HP_WMI_COMMON_ELEMENTS,
+	"LowerBound",
+	"UpperBound",
+	"IntValue"
+};
+
+const char *hp_wmi_enumeration_elements[] = {
+	HP_WMI_COMMON_ELEMENTS,
+	"CurrentValue",
+	"Size"
+};
+
+const char *hp_wmi_orderedlist_elements[] = {
+	HP_WMI_COMMON_ELEMENTS,
+	"Size"
+};
+
+const char *hp_wmi_password_elements[] = {
+	HP_WMI_COMMON_ELEMENTS,
+	"MinLength",
+	"MaxLength",
+	"Size",
+	"SupportedEncoding",
+	"IsSet"
+};
+
+const char **hp_wmi_elements[] = {
+	hp_wmi_string_elements,
+	hp_wmi_integer_elements,
+	hp_wmi_enumeration_elements,
+	hp_wmi_orderedlist_elements,
+	hp_wmi_password_elements
+};
+
+const int hp_wmi_elements_count[] = {
+	ARRAY_SIZE(hp_wmi_string_elements),
+	ARRAY_SIZE(hp_wmi_integer_elements),
+	ARRAY_SIZE(hp_wmi_enumeration_elements),
+	ARRAY_SIZE(hp_wmi_orderedlist_elements),
+	ARRAY_SIZE(hp_wmi_password_elements)
+};
+
+const char *hp_wmi_classes[] = {
+	"HPBIOS_BIOSString",
+	"HPBIOS_BIOSInteger",
+	"HPBIOS_BIOSEnumeration",
+	"HPBIOS_BIOSOrderedList",
+	"HPBIOS_BIOSPassword"
+};
+
+static DEFINE_MUTEX(buf_mutex);
+static int settings_buffer_size;
+static int buf_alloc_size;
+static char *hp_bios_settings_buffer;
+
+
+static int append_package_elements_to_buffer(union acpi_object *obj,
+					     char *buf, int alloc_size, enum hp_wmi_data_type type)
+{
+	int i;
+	union acpi_object *pobj = NULL;
+	char *value = NULL;
+	int value_len;
+	char *tmpstr = NULL;
+	char *part_tmp = NULL;
+	int tmp_len = 0;
+	char *part = NULL;
+	int status = 0;
+	int size = 0;
+	int buf_size;
+
+	if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
+		return -EINVAL;
+
+	if (obj->type != ACPI_TYPE_PACKAGE)
+		return -EINVAL;
+
+	buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
+	buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf, hp_wmi_classes[type]);
+
+	for (i = 0; i < 3; i++) {
+		pobj = &(obj->package.elements[i]);
+		if (pobj->type == ACPI_TYPE_STRING) {
+			status = convert_hexstr_to_str(&pobj->string.pointer,
+						       pobj->string.length, &value, &value_len);
+			if (ACPI_FAILURE(status))
+				continue;
+			/*
+			 * Skip 'Value' (HP_WMI_COMMON_ELEMENTS) since
+			 * 'CurrentValue' is reported.
+			 */
+			if (type != HPWMI_ENUMERATION_TYPE || i != 1)
+				buf_size = snprintf(buf, alloc_size,
+						    "%s\t\"%s\": \"%s\",\n",
+						    buf,
+						    hp_wmi_elements[type][i], value);
+
+		}
+		kfree(value);
+		value = NULL;
+	}
+
+	for (i = 3; i < hp_wmi_elements_count[type]; i++) {
+		pobj = &(obj->package.elements[i]);
+
+		if (type == HPWMI_ENUMERATION_TYPE &&
+		    i == 9 &&
+		    pobj->type == ACPI_TYPE_STRING) {
+			/*
+			 * Report "CurrentValue" as "Value"
+			 */
+			status = convert_hexstr_to_str(&pobj->string.pointer,
+						       pobj->string.length,
+						       &value, &value_len);
+			if (ACPI_FAILURE(status))
+				continue;
+
+			buf_size = snprintf(buf, alloc_size,
+					    "%s\t\"Value\": \"%s\",\n",
+					    buf, value);
+			kfree(value);
+			value = NULL;
+
+		} else if (type == HPWMI_PASSWORD_TYPE &&
+			   i == 12 &&
+			   pobj->type == ACPI_TYPE_STRING) {
+			/*
+			 * Report list of "SupportEncoding"
+			 *
+			 *	"SupportedEncoding": [
+			 *		"utf-16"
+			 *	],
+			 *
+			 */
+
+			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
+					    buf, hp_wmi_elements[type][i]);
+			while (size--) {
+				pobj = &(obj->package.elements[i]);
+				status = convert_hexstr_to_str(&pobj->string.pointer,
+							       pobj->string.length,
+							       &value, &value_len);
+				if (ACPI_FAILURE(status))
+					continue;
+
+				if (size) {
+					buf_size = snprintf(buf, alloc_size,
+							    "%s\t\t\"%s\",\n", buf, value);
+					i++;
+				} else
+					buf_size = snprintf(buf, alloc_size,
+							    "%s\t\t\"%s\"\n", buf, value);
+
+				kfree(value);
+				value = NULL;
+
+			}
+			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
+			continue;
+
+		} else if (pobj->type == ACPI_TYPE_INTEGER) {
+			/*
+			 * Report "PrerequisiteSize" and "Size" values
+			 *	...
+			 *	"PrerequisiteSize": 1,
+			 *	...
+			 *	"Size": 2,
+			 *	...
+			 */
+			if (i == 7)
+				size = pobj->integer.value;
+			else if (type == HPWMI_ORDEREDLIST_TYPE && i == 9)
+				size = pobj->integer.value;
+			else if (type == HPWMI_ENUMERATION_TYPE && i == 10)
+				size = pobj->integer.value;
+			else if (type == HPWMI_PASSWORD_TYPE && i == 11)
+				size = pobj->integer.value;
+
+			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": %lld,\n", buf,
+					    hp_wmi_elements[type][i], pobj->integer.value);
+		}
+	}
+
+	if (type == HPWMI_ENUMERATION_TYPE) {
+		buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\": [\n", buf);
+		for (i = 0; i < size; i++) {
+			pobj = &(obj->package.elements[i + hp_wmi_elements_count[type]]);
+
+			status = convert_hexstr_to_str(&pobj->string.pointer,
+						       pobj->string.length,
+						       &value, &value_len);
+			if (ACPI_FAILURE(status))
+				break;
+
+			/*
+			 * Report list of "PossibleValues" of size
+			 * "Size"
+			 *	...
+			 *	"Size": 2,
+			 *	"PossibleValues": [
+			 *			"Disable",
+			 *			"Enable"]
+			 */
+			if (i == (size - 1))
+				buf_size = snprintf(buf, alloc_size,
+						    "%s\t\t\"%s\"\n", buf, value);
+			else
+				buf_size = snprintf(buf, alloc_size,
+						    "%s\t\t\"%s\",\n", buf, value);
+			kfree(value);
+			value = NULL;
+		}
+		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
+	}
+
+	if (type == HPWMI_ORDEREDLIST_TYPE) {
+		buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n", buf);
+		if (size <= 0)
+			goto finish_ordered_list;
+
+		pobj = &(obj->package.elements[hp_wmi_elements_count[type]]);
+		status = convert_hexstr_to_str(&pobj->string.pointer,
+					       pobj->string.length, &value, &value_len);
+		if (ACPI_FAILURE(status))
+			goto finish_ordered_list;
+
+		/*
+		 * Ordered list data is stored in hex and comma separated format
+		 * Convert the data and split it to show each element
+		 */
+		status = convert_hexstr_to_str(&value, value_len, &tmpstr, &tmp_len);
+		if (ACPI_FAILURE(status))
+			goto finish_ordered_list;
+
+		part_tmp = tmpstr;
+		part = strsep(&part_tmp, ",");
+		while (part) {
+			buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"", buf, part);
+			part = strsep(&part_tmp, ",");
+			if (part)
+				buf_size = snprintf(buf, alloc_size, "%s,\n", buf);
+			else
+				buf_size = snprintf(buf, alloc_size, "%s\n", buf);
+		}
+	}
+
+finish_ordered_list:
+	if (type == HPWMI_ORDEREDLIST_TYPE)
+		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
+
+	/*
+	 * remove trailing comma
+	 */
+	if (buf_size > 3)
+		buf[buf_size - 2] = ' ';
+
+	kfree(tmpstr);
+	kfree(value);
+	return snprintf(buf, alloc_size, "%s},\n", buf);
+}
+
+static int append_buffer_elements_to_buffer(union acpi_object *obj,
+					    char *buf, int alloc_size, enum hp_wmi_data_type type)
+{
+	int buf_size;
+	int status;
+	char *str = NULL;
+	int i;
+	int j;
+	int integer;
+	int size = 0;
+
+	if (type >= ARRAY_SIZE(hp_wmi_classes) || !buf || !obj)
+		return -EINVAL;
+
+	if (obj->type != ACPI_TYPE_BUFFER)
+		return -EINVAL;
+
+	buf_size = snprintf(buf, alloc_size, "%s{\n", buf);
+	buf_size = snprintf(buf, alloc_size, "%s\t\"Class\": \"%s\",\n", buf, hp_wmi_classes[type]);
+
+	for (i = 0; i < 3; i++) {
+		status = get_string_from_buffer((u16 **)&obj->buffer.pointer, &str);
+		if (ACPI_SUCCESS(status)) {
+			/*
+			 * Skip 'Value' (HP_WMI_COMMON_ELEMENTS) since
+			 * 'CurrentValue' is reported.
+			 */
+			if (type != HPWMI_ENUMERATION_TYPE || i != 1)
+				buf_size = snprintf(buf, alloc_size,
+						    "%s\t\"%s\": \"%s\",\n",
+						    buf,
+						    hp_wmi_elements[type][i], str);
+		}
+		kfree(str);
+		str = NULL;
+
+	}
+
+	for (i = 3; i < hp_wmi_elements_count[type]; i++) {
+		if (type == HPWMI_ENUMERATION_TYPE && i == 9) {
+			status = get_string_from_buffer((u16 **)&obj->buffer.pointer, &str);
+			if (ACPI_SUCCESS(status)) {
+				/*
+				 * Report "CurrentValue" as "Value"
+				 */
+				buf_size = snprintf(buf, alloc_size,
+						    "%s\t\"Value\": \"%s\",\n", buf, str);
+			}
+			kfree(str);
+			str = NULL;
+			continue;
+
+		} else if (type == HPWMI_PASSWORD_TYPE && i == 12) {
+			/*
+			 * Report list of "SupportEncoding"
+			 *
+			 *	"SupportedEncoding": [
+			 *		"utf-16"
+			 *	],
+			 *
+			 */
+
+			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": [\n",
+					    buf, hp_wmi_elements[type][i]);
+			for (j = 0; j < size; j++) {
+				status = get_string_from_buffer((u16 **)&obj->buffer.pointer, &str);
+				if (ACPI_SUCCESS(status)) {
+					if (j == size - 1)
+						buf_size = snprintf(buf, alloc_size,
+								    "%s\t\t\"%s\"\n", buf, str);
+					else
+						buf_size = snprintf(buf, alloc_size,
+								    "%s\t\t\"%s\",\n", buf, str);
+				}
+				kfree(str);
+				str = NULL;
+			}
+			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
+			continue;
+		}
+
+		size = 0;
+		status = get_integer_from_buffer((int **)&obj->buffer.pointer, &integer);
+		if (ACPI_SUCCESS(status)) {
+			/*
+			 * Report "PrerequisiteSize" and "Size" values
+			 *	...
+			 *	"PrerequisiteSize": 1,
+			 *	...
+			 *	"Size": 2,
+			 *	...
+			 */
+			if (i == 7)
+				size = integer;
+			else if (type == HPWMI_ENUMERATION_TYPE && i == 10)
+				size = integer;
+			else if (type == HPWMI_ORDEREDLIST_TYPE && i == 9)
+				size = integer;
+			else if (type == HPWMI_PASSWORD_TYPE && i == 11)
+				size = integer;
+
+			buf_size = snprintf(buf, alloc_size, "%s\t\"%s\": %d,\n", buf,
+					    hp_wmi_elements[type][i], integer);
+		}
+
+		if (size > 20)
+			pr_warn("%s exceeded the maximum number of elements supported or data may be malformed\n",
+				hp_wmi_elements[type][i]);
+
+		if (ACPI_SUCCESS(status) && i == 7) {
+			buf_size = snprintf(buf, alloc_size, "%s\t\"Prerequisites\": [\n", buf);
+			for (j = 0; j < size; j++) {
+				status = get_string_from_buffer((u16 **)&obj->buffer.pointer, &str);
+				if (ACPI_SUCCESS(status)) {
+					buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"", buf, str);
+
+					if (j == size - 1)
+						buf_size = snprintf(buf, alloc_size, "%s\n", buf);
+					else
+						buf_size = snprintf(buf, alloc_size, "%s,\n", buf);
+
+				}
+				kfree(str);
+				str = NULL;
+			}
+			buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
+		}
+	}
+
+	if (type == HPWMI_ENUMERATION_TYPE || type == HPWMI_ORDEREDLIST_TYPE) {
+		if (type == HPWMI_ENUMERATION_TYPE)
+			buf_size = snprintf(buf, alloc_size, "%s\t\"PossibleValues\": [\n", buf);
+		else
+			buf_size = snprintf(buf, alloc_size, "%s\t\"Elements\": [\n", buf);
+
+		for (i = 0; i < size; i++) {
+			status = get_string_from_buffer((u16 **)&obj->buffer.pointer, &str);
+			if (ACPI_SUCCESS(status)) {
+				buf_size = snprintf(buf, alloc_size, "%s\t\t\"%s\"", buf, str);
+
+				if (i == size - 1)
+					buf_size = snprintf(buf, alloc_size, "%s\n", buf);
+				else
+					buf_size = snprintf(buf, alloc_size, "%s,\n", buf);
+
+			}
+			kfree(str);
+			str = NULL;
+		}
+		buf_size = snprintf(buf, alloc_size, "%s\t],\n", buf);
+	}
+
+	/*
+	 * remove trailing comma
+	 */
+	if (buf_size > 3)
+		buf[buf_size - 2] = ' ';
+
+	return snprintf(buf, alloc_size, "%s},\n", buf);
+}
+
+static int hp_bios_settings_free_buffer(void)
+{
+	mutex_lock(&buf_mutex);
+	kfree(hp_bios_settings_buffer);
+	settings_buffer_size = 0;
+	buf_alloc_size = 0;
+	mutex_unlock(&buf_mutex);
+
+	return 0;
+}
+
+static int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
+					   int *alloc_size,
+					   struct mutex *buf_mutex)
+{
+	int new_buffer_size;
+	char *new_buf = NULL;
+	int ret = 0;
+
+	if (*buf_size + PAGE_SIZE >= *alloc_size) {
+		new_buffer_size = buf_alloc_size + 2 * PAGE_SIZE;
+
+		mutex_lock(buf_mutex);
+		new_buf = krealloc(*buf, new_buffer_size, GFP_KERNEL);
+		mutex_unlock(buf_mutex);
+		if (new_buf) {
+			mutex_lock(buf_mutex);
+			*buf = new_buf;
+			*alloc_size = ksize(new_buf);
+			mutex_unlock(buf_mutex);
+		} else {
+			hp_bios_settings_free_buffer();
+			ret = -ENOMEM;
+		}
+	}
+
+	return ret;
+}
+
+static int append_settings_to_buffer(char *guid, int type, char **buf,
+				     int *buf_size, int *alloc_size,
+				     struct mutex *buf_mutex)
+{
+	union acpi_object *obj = NULL;
+	int ret = 0;
+	int status = 0;
+	int instance = 0;
+
+	/*
+	 * Query all the instances until to receive a AE_BAD_PARAMETER
+	 */
+	do {
+		ret = hp_wmi_get_setting_object(guid, instance++, &obj);
+		if (ACPI_SUCCESS(ret) && obj != NULL) {
+			status = 0;
+			if (obj->type == ACPI_TYPE_PACKAGE) {
+				mutex_lock(buf_mutex);
+				status = append_package_elements_to_buffer(obj,
+							*buf, *alloc_size, type);
+				if (status > 0)
+					*buf_size = status;
+				mutex_unlock(buf_mutex);
+
+			} else if (obj->type == ACPI_TYPE_BUFFER) {
+				mutex_lock(buf_mutex);
+				status = append_buffer_elements_to_buffer(obj,
+							*buf, *alloc_size, type);
+				if (status > 0)
+					*buf_size = status;
+				mutex_unlock(buf_mutex);
+
+			} else
+				pr_warn("The retrieved object type(%d) is not supported yet\n",
+					obj->type);
+
+			ret = hp_bios_settings_realloc_buffer(buf, buf_size, alloc_size, buf_mutex);
+		}
+
+		kfree(obj);
+		obj = NULL;
+
+	} while (ACPI_SUCCESS(ret));
+
+	/*
+	 * AE_BAD_PARAMETER means the loop ended by exhaustion
+	 */
+	if (ret == AE_BAD_PARAMETER)
+		ret = 0;
+
+	return ret;
+}
+
+static int hp_bios_settings_fill_buffer(void)
+{
+	int status = 0;
+	int initial_buffer_size = 20 * PAGE_SIZE;
+
+	mutex_lock(&buf_mutex);
+	hp_bios_settings_buffer = kmalloc(initial_buffer_size, GFP_KERNEL);
+	mutex_unlock(&buf_mutex);
+	if (!hp_bios_settings_buffer)
+		return -ENOMEM;
+
+	mutex_lock(&buf_mutex);
+	buf_alloc_size = ksize(hp_bios_settings_buffer);
+	settings_buffer_size = snprintf(hp_bios_settings_buffer,
+					buf_alloc_size, "[\n");
+	mutex_unlock(&buf_mutex);
+
+	status = append_settings_to_buffer(HPWMI_STRING_GUID,
+		HPWMI_STRING_TYPE, &hp_bios_settings_buffer,
+		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
+	if (ACPI_FAILURE(status))
+		pr_err("error 0x%x occurred retrieving string instances\n", status);
+
+	status = append_settings_to_buffer(HPWMI_INTEGER_GUID,
+		HPWMI_INTEGER_TYPE, &hp_bios_settings_buffer,
+		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
+	if (ACPI_FAILURE(status))
+		pr_err("error 0x%x occurred retrieving integer instances\n", status);
+
+	status = append_settings_to_buffer(HPWMI_ENUMERATION_GUID,
+		HPWMI_ENUMERATION_TYPE, &hp_bios_settings_buffer,
+		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
+	if (ACPI_FAILURE(status))
+		pr_err("error 0x%x occurred retrieving enumeration instances\n", status);
+
+	status = append_settings_to_buffer(HPWMI_ORDEREDLIST_GUID,
+		HPWMI_ORDEREDLIST_TYPE, &hp_bios_settings_buffer,
+		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
+	if (ACPI_FAILURE(status))
+		pr_err("error 0x%x occurred retrieving ordered list instances\n", status);
+
+	status = append_settings_to_buffer(HPWMI_PASSWORD_GUID,
+		HPWMI_PASSWORD_TYPE, &hp_bios_settings_buffer,
+		&settings_buffer_size, &buf_alloc_size, &buf_mutex);
+	if (ACPI_FAILURE(status))
+		pr_err("error 0x%x occurred retrieving password list instances\n", status);
+
+	mutex_lock(&buf_mutex);
+	/*
+	 * remove trailing comma
+	 */
+	if (settings_buffer_size >= 3) {
+		if (hp_bios_settings_buffer[settings_buffer_size - 2] == ',')
+			hp_bios_settings_buffer[settings_buffer_size - 2] = ' ';
+	}
+	settings_buffer_size = snprintf(hp_bios_settings_buffer,
+					buf_alloc_size, "%s]\n",
+					hp_bios_settings_buffer);
+	mutex_unlock(&buf_mutex);
+
+	return settings_buffer_size;
+}
+
+/*
+ * sure_admin_settings_read - Return a formatted file with settings
+ *                              and possible options read from BIOS
+ *
+ * @filp:  Pointer to file of settings read from BIOS
+ * @kobj:  Pointer to a kernel object of things that show up as directory in the sysfs filesystem.
+ * @attr:  Pointer to list of read attributes
+ * @buf:   Pointer to buffer
+ * @off:   File current offset
+ * @count: Buffer size
+ *
+ * Returns the count of unicode chars read if successful, otherwise
+ *		-ENOMEM unable to allocate memory
+ *		-EINVAL buffer not allocated or too small
+ *
+ */
+static ssize_t sure_admin_settings_read(struct file *filp, struct kobject *kobj,
+					struct bin_attribute *attr, char *buf, loff_t off, size_t count)
+{
+	ssize_t ret;
+
+	/* clear the buffer when offset is pointing to the last position */
+	if (off >= settings_buffer_size && settings_buffer_size > 0) {
+		hp_bios_settings_free_buffer();
+		return 0;
+	}
+
+	/* clear the buffer whenever the read starts from the first position */
+	if (off == 0 && settings_buffer_size > 0)
+		hp_bios_settings_free_buffer();
+
+	if (settings_buffer_size == 0)
+		hp_bios_settings_fill_buffer();
+
+	mutex_lock(&buf_mutex);
+	ret = memory_read_from_buffer(buf, count, &off, hp_bios_settings_buffer,
+				      settings_buffer_size);
+	mutex_unlock(&buf_mutex);
+
+	return ret;
+}
+
+
+/*
+ * ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
+ *
+ * @p:   Unicode buffer address
+ * @str: string to convert to unicode
+ *
+ * Returns a void pointer to the buffer containing unicode string
+ */
+static void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
+{
+	int len = strlen(str);
+
+	/*
+	 * Add null character when reading an empty string
+	 */
+	if (len == 0) {
+		*p++ = 2;
+		*p++ = (u8)0x00;
+		return p;
+	}
+	*p++ = len * 2;
+	utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
+	p += len;
+
+	return p;
+}
+
+/*
+ * hp_wmi_set_bios_setting - Set setting's value in BIOS
+ *
+ * @input_buffer: Input buffer address
+ * @input_size:   Input buffer size
+ *
+ * Returns: Count of unicode characters written to BIOS if successful, otherwise
+ *		-ENOMEM unable to allocate memory
+ *		-EINVAL buffer not allocated or too small
+ */
+static int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
+{
+	union acpi_object *obj;
+	struct acpi_buffer input = {input_size, input_buffer};
+	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+	int ret = 0;
+
+	ret = wmi_evaluate_method(HPWMI_SETBIOSSETTING_GUID, 0, 1, &input, &output);
+
+	obj = output.pointer;
+	if (!obj)
+		return -EINVAL;
+
+	if (obj->type != ACPI_TYPE_INTEGER)
+		ret = -EINVAL;
+
+	ret = obj->integer.value;
+	kfree(obj);
+	return ret;
+}
+
+/* Sure Admin Functions */
+
+#define UTF_PREFIX			((unsigned char *)"<utf-16/>")
+#define BEAM_PREFIX			((unsigned char *)"<BEAM/>")
+
+/*
+ * sure_admin_settings_write - Write the contents of a formatted file
+ *                               with settings and performs the logic
+ *                               to change any settings in BIOS.
+ *
+ * @filp:  Pointer to file of settings to be written to BIOS
+ * @kobj:  Pointer to a kernel object of things that show up as directory in the sysfs filesystem.
+ * @attr:  Pointer to list of attributes for the write operation
+ * @buf:   Pointer to buffer
+ * @off:   File current offset
+ * @count: Buffer size
+ *
+ *
+ * Returns the count of unicode characters written to BIOS if successful, otherwise
+ *		-ENOMEM unable to allocate memory
+ *		-EINVAL buffer not allocated or too small
+ *
+ */
+static ssize_t sure_admin_settings_write(struct file *filp, struct kobject *kobj,
+			struct bin_attribute *attr, char *buf, loff_t off, size_t count)
+{
+	int status = 0;
+	char *part = NULL;
+	int part_len = 0;
+	unsigned short *buffer = NULL;
+	unsigned short *tmpstr = NULL;
+	int buffer_size = (count + strlen(UTF_PREFIX)) * sizeof(unsigned short);
+
+	buffer = kmalloc(buffer_size, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	tmpstr = buffer;
+	part = strsep(&buf, ",");
+	if (!part) {
+		status = -EINVAL;
+		goto out_free;
+	}
+	tmpstr = ascii_to_utf16_unicode(tmpstr, part);
+	part = strsep(&buf, ",");
+	if (!part) {
+		status = -EINVAL;
+		goto out_free;
+	}
+
+	/* Add extra buffer space when encountering an empty string */
+	if (!strlen(part))
+		buffer_size += sizeof(unsigned short);
+	tmpstr = ascii_to_utf16_unicode(tmpstr, part);
+	part = strsep(&buf, ",");
+	if (!part) {
+		status = -EINVAL;
+		goto out_free;
+	}
+	part_len = strlen(part) - 1;
+	part[part_len] = '\0';
+
+	if (strncmp(part, BEAM_PREFIX, strlen(BEAM_PREFIX)) == 0) {
+	       /*
+		* BEAM_PREFIX is append to buffer when a signature
+		* is provided and Sure Admin is enabled in BIOS
+		*/
+		// BEAM_PREFIX found, convert part to unicode
+		tmpstr = ascii_to_utf16_unicode(tmpstr, part);
+		// decrease buffer size allocated initially for UTF_PREFIX
+		buffer_size -= strlen(UTF_PREFIX) * sizeof(unsigned short);
+	} else {
+		/*
+		 * UTF-16 prefix is append to the * buffer when a BIOS
+		 * admin password is configured in BIOS
+		 */
+
+		// append UTF_PREFIX to part and then convert it to unicode
+		part = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX, part);
+		if (!part)
+			goto out_free;
+
+		tmpstr = ascii_to_utf16_unicode(tmpstr, part);
+		kfree(part);
+	}
+
+	part = strsep(&buf, ",");
+	if (part) {
+		status = -EINVAL;
+		goto out_free;
+	}
+	status = hp_wmi_set_bios_setting(buffer, buffer_size);
+	if (ACPI_FAILURE(status))
+		status = -EINVAL;
+
+out_free:
+	kfree(buffer);
+	if (ACPI_SUCCESS(status))
+		return count;
+	return status;
+}
+
+HPWMI_BINATTR_RW(sure_admin, settings, 0);
+
+static struct bin_attribute *sure_admin_binattrs[] = {
+	&sure_admin_settings,
+	NULL,
+};
+
+static const struct attribute_group sure_admin_group = {
+	.name = "sure_admin",
+	.bin_attrs = sure_admin_binattrs,
+};
+
 static DEVICE_ATTR_RO(display);
 static DEVICE_ATTR_RO(hddtemp);
 static DEVICE_ATTR_RW(als);
@@ -1050,6 +2026,7 @@  static const struct attribute_group *hp_wmi_groups[] = {
 	&hp_wmi_group,
 	&spm_group,
 	&sure_start_group,
+	&sure_admin_group,
 	NULL,
 };