HID: uhid: Add UHID_CREATE2 + UHID_INPUT2

Commit Message

Petri Gynther March 19, 2014, 3:45 a.m. UTC

UHID_CREATE2:
HID report descriptor data (rd_data) is an array in struct uhid_create2_req,
instead of a pointer. Enables use from languages that don't support pointers,
e.g. Python.

UHID_INPUT2:
Data array is the last field of struct uhid_input2_req. Enables userspace to
write only the required bytes to kernel (ev.type + ev.u.input2.size + the part
of the data array that matters), instead of the entire struct uhid_input2_req.

Signed-off-by: Petri Gynther <[e-mail]>
---
 Documentation/hid/uhid.txt | 11 +++++++
 drivers/hid/uhid.c         | 80 ++++++++++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/uhid.h  | 23 +++++++++++++
 3 files changed, 114 insertions(+)

Comments

David Herrmann March 23, 2014, 2:22 p.m. UTC | #1

Hi

On Wed, Mar 19, 2014 at 4:45 AM, Petri Gynther <[e-mail]> wrote:
> UHID_CREATE2:
> HID report descriptor data (rd_data) is an array in struct uhid_create2_req,
> instead of a pointer. Enables use from languages that don't support pointers,
> e.g. Python.

..and this also makes the x32-COMPAT crap obsolete.

>
> UHID_INPUT2:
> Data array is the last field of struct uhid_input2_req. Enables userspace to
> write only the required bytes to kernel (ev.type + ev.u.input2.size + the part
> of the data array that matters), instead of the entire struct uhid_input2_req.

We should have swapped these fields right from the beginning. We
explicitly support truncated input, but I only ever tested that with
output, not input.. Thanks for fixing that!

> Signed-off-by: Petri Gynther <[e-mail]>
> ---
>  Documentation/hid/uhid.txt | 11 +++++++
>  drivers/hid/uhid.c         | 80 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/uhid.h  | 23 +++++++++++++
>  3 files changed, 114 insertions(+)
>
> diff --git a/Documentation/hid/uhid.txt b/Documentation/hid/uhid.txt
> index dc35a2b..ee65936 100644
> --- a/Documentation/hid/uhid.txt
> +++ b/Documentation/hid/uhid.txt
> @@ -93,6 +93,11 @@ the request was handled successfully.
>    event to the kernel. The payload is of type struct uhid_create_req and
>    contains information about your device. You can start I/O now.
>
> +  UHID_CREATE2:
> +  Same as UHID_CREATE, but the HID report descriptor data (rd_data) is an array
> +  inside struct uhid_create2_req, instead of a pointer to a separate array.
> +  Enables use from languages that don't support pointers, e.g. Python.
> +
>    UHID_DESTROY:
>    This destroys the internal HID device. No further I/O will be accepted. There
>    may still be pending messages that you can receive with read() but no further
> @@ -105,6 +110,12 @@ the request was handled successfully.
>    contains a data-payload. This is the raw data that you read from your device.
>    The kernel will parse the HID reports and react on it.
>
> +  UHID_INPUT2:
> +  Same as UHID_INPUT, but the data array is the last field of uhid_input2_req.
> +  Enables userspace to write only the required bytes to kernel (ev.type +
> +  ev.u.input2.size + the part of the data array that matters), instead of
> +  the entire struct uhid_input2_req.
> +
>    UHID_FEATURE_ANSWER:
>    If you receive a UHID_FEATURE request you must answer with this request. You
>    must copy the "id" field from the request into the answer. Set the "err" field
> diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
> index cedc6da..c5ee173 100644
> --- a/drivers/hid/uhid.c
> +++ b/drivers/hid/uhid.c
> @@ -407,6 +407,69 @@ err_free:
>         return ret;
>  }
>
> +static int uhid_dev_create2(struct uhid_device *uhid,
> +                           const struct uhid_event *ev)
> +{
> +       struct hid_device *hid;
> +       int ret;
> +
> +       if (uhid->running)
> +               return -EALREADY;
> +
> +       uhid->rd_size = ev->u.create2.rd_size;
> +       if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE)
> +               return -EINVAL;
> +
> +       uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL);
> +       if (!uhid->rd_data)
> +               return -ENOMEM;
> +
> +       memcpy(uhid->rd_data, ev->u.create2.rd_data, uhid->rd_size);

Why don't we just use uhid_dev_create() and do this:

if (ev->type == UHID_CREATE) {
        ...copy_from_user()...
} else if (ev->type == UHID_CREATE2) {
        memcpy(...);
}

This way we can avoid copying this whole function.

> +
> +       hid = hid_allocate_device();
> +       if (IS_ERR(hid)) {
> +               ret = PTR_ERR(hid);
> +               goto err_free;
> +       }
> +
> +       strncpy(hid->name, ev->u.create2.name, 127);
> +       hid->name[127] = 0;
> +       strncpy(hid->phys, ev->u.create2.phys, 63);
> +       hid->phys[63] = 0;
> +       strncpy(hid->uniq, ev->u.create2.uniq, 63);
> +       hid->uniq[63] = 0;
> +
> +       hid->ll_driver = &uhid_hid_driver;
> +       hid->hid_get_raw_report = uhid_hid_get_raw;
> +       hid->hid_output_raw_report = uhid_hid_output_raw;
> +       hid->bus = ev->u.create2.bus;
> +       hid->vendor = ev->u.create2.vendor;
> +       hid->product = ev->u.create2.product;
> +       hid->version = ev->u.create2.version;
> +       hid->country = ev->u.create2.country;
> +       hid->driver_data = uhid;
> +       hid->dev.parent = uhid_misc.this_device;
> +
> +       uhid->hid = hid;
> +       uhid->running = true;
> +
> +       ret = hid_add_device(hid);
> +       if (ret) {
> +               hid_err(hid, "Cannot register HID device\n");
> +               goto err_hid;
> +       }
> +
> +       return 0;
> +
> +err_hid:
> +       hid_destroy_device(hid);
> +       uhid->hid = NULL;
> +       uhid->running = false;
> +err_free:
> +       kfree(uhid->rd_data);
> +       return ret;
> +}
> +
>  static int uhid_dev_destroy(struct uhid_device *uhid)
>  {
>         if (!uhid->running)
> @@ -435,6 +498,17 @@ static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
>         return 0;
>  }
>
> +static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
> +{
> +       if (!uhid->running)
> +               return -EINVAL;
> +
> +       hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
> +                        min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
> +
> +       return 0;
> +}
> +
>  static int uhid_dev_feature_answer(struct uhid_device *uhid,
>                                    struct uhid_event *ev)
>  {
> @@ -571,12 +645,18 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
>         case UHID_CREATE:
>                 ret = uhid_dev_create(uhid, &uhid->input_buf);
>                 break;
> +       case UHID_CREATE2:
> +               ret = uhid_dev_create2(uhid, &uhid->input_buf);
> +               break;
>         case UHID_DESTROY:
>                 ret = uhid_dev_destroy(uhid);
>                 break;
>         case UHID_INPUT:
>                 ret = uhid_dev_input(uhid, &uhid->input_buf);
>                 break;
> +       case UHID_INPUT2:
> +               ret = uhid_dev_input2(uhid, &uhid->input_buf);
> +               break;
>         case UHID_FEATURE_ANSWER:
>                 ret = uhid_dev_feature_answer(uhid, &uhid->input_buf);
>                 break;
> diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h
> index 414b74b..1e3b09c 100644
> --- a/include/uapi/linux/uhid.h
> +++ b/include/uapi/linux/uhid.h
> @@ -21,6 +21,7 @@
>
>  #include <linux/input.h>
>  #include <linux/types.h>
> +#include <linux/hid.h>
>
>  enum uhid_event_type {
>         UHID_CREATE,
> @@ -34,6 +35,8 @@ enum uhid_event_type {
>         UHID_INPUT,
>         UHID_FEATURE,
>         UHID_FEATURE_ANSWER,
> +       UHID_CREATE2,
> +       UHID_INPUT2,
>  };
>
>  struct uhid_create_req {
> @@ -50,6 +53,19 @@ struct uhid_create_req {
>         __u32 country;
>  } __attribute__((__packed__));
>
> +struct uhid_create2_req {
> +       __u8 name[128];
> +       __u8 phys[64];
> +       __u8 uniq[64];
> +       __u16 rd_size;
> +       __u16 bus;
> +       __u32 vendor;
> +       __u32 product;
> +       __u32 version;
> +       __u32 country;
> +       __u8 rd_data[HID_MAX_DESCRIPTOR_SIZE];
> +} __attribute__((__packed__));
> +
>  #define UHID_DATA_MAX 4096
>
>  enum uhid_report_type {
> @@ -63,6 +79,11 @@ struct uhid_input_req {
>         __u16 size;
>  } __attribute__((__packed__));
>
> +struct uhid_input2_req {
> +       __u16 size;
> +       __u8 data[UHID_DATA_MAX];
> +} __attribute__((__packed__));
> +
>  struct uhid_output_req {
>         __u8 data[UHID_DATA_MAX];
>         __u16 size;
> @@ -100,6 +121,8 @@ struct uhid_event {
>                 struct uhid_output_ev_req output_ev;
>                 struct uhid_feature_req feature;
>                 struct uhid_feature_answer_req feature_answer;
> +               struct uhid_create2_req create2;
> +               struct uhid_input2_req input2;

We change the size of uhid_output_req here, but I think that is fine.
But you might wanna note that down in the commit-message.

Patch looks fine. If you fix the minor issues, this is:
Reviewed-by: David Herrmann <[e-mail]>

And please always put Jiri on CC for all HID patches: "Jiri Kosina
<[e-mail]>"

Thanks
David

>         } u;
>  } __attribute__((__packed__));
>
> --
> 1.9.0.279.gdc9e3eb
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
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Jiri Kosina March 24, 2014, 12:50 p.m. UTC | #2

On Sun, 23 Mar 2014, David Herrmann wrote:

[ ... snip ... ]
> Patch looks fine. If you fix the minor issues, this is:
> Reviewed-by: David Herrmann <[e-mail]>
> 
> And please always put Jiri on CC for all HID patches: "Jiri Kosina
> <[e-mail]>"

Indeed, that helps. Petri, could you please resend the patch proper to me 
with David's 'Reviewed-by' tag included?

Thanks,

Petri Gynther March 24, 2014, 7:04 p.m. UTC | #3

Hi David and Jiri,

On Sun, Mar 23, 2014 at 7:22 AM, David Herrmann <[e-mail]> wrote:
> Hi
>
> On Wed, Mar 19, 2014 at 4:45 AM, Petri Gynther <[e-mail]> wrote:
>> UHID_CREATE2:
>> HID report descriptor data (rd_data) is an array in struct uhid_create2_req,
>> instead of a pointer. Enables use from languages that don't support pointers,
>> e.g. Python.
>
> ..and this also makes the x32-COMPAT crap obsolete.
>
>>
>> UHID_INPUT2:
>> Data array is the last field of struct uhid_input2_req. Enables userspace to
>> write only the required bytes to kernel (ev.type + ev.u.input2.size + the part
>> of the data array that matters), instead of the entire struct uhid_input2_req.
>
> We should have swapped these fields right from the beginning. We
> explicitly support truncated input, but I only ever tested that with
> output, not input.. Thanks for fixing that!
>
>> Signed-off-by: Petri Gynther <[e-mail]>
>> ---
>>  Documentation/hid/uhid.txt | 11 +++++++
>>  drivers/hid/uhid.c         | 80 ++++++++++++++++++++++++++++++++++++++++++++++
>>  include/uapi/linux/uhid.h  | 23 +++++++++++++
>>  3 files changed, 114 insertions(+)
>>
>> diff --git a/Documentation/hid/uhid.txt b/Documentation/hid/uhid.txt
>> index dc35a2b..ee65936 100644
>> --- a/Documentation/hid/uhid.txt
>> +++ b/Documentation/hid/uhid.txt
>> @@ -93,6 +93,11 @@ the request was handled successfully.
>>    event to the kernel. The payload is of type struct uhid_create_req and
>>    contains information about your device. You can start I/O now.
>>
>> +  UHID_CREATE2:
>> +  Same as UHID_CREATE, but the HID report descriptor data (rd_data) is an array
>> +  inside struct uhid_create2_req, instead of a pointer to a separate array.
>> +  Enables use from languages that don't support pointers, e.g. Python.
>> +
>>    UHID_DESTROY:
>>    This destroys the internal HID device. No further I/O will be accepted. There
>>    may still be pending messages that you can receive with read() but no further
>> @@ -105,6 +110,12 @@ the request was handled successfully.
>>    contains a data-payload. This is the raw data that you read from your device.
>>    The kernel will parse the HID reports and react on it.
>>
>> +  UHID_INPUT2:
>> +  Same as UHID_INPUT, but the data array is the last field of uhid_input2_req.
>> +  Enables userspace to write only the required bytes to kernel (ev.type +
>> +  ev.u.input2.size + the part of the data array that matters), instead of
>> +  the entire struct uhid_input2_req.
>> +
>>    UHID_FEATURE_ANSWER:
>>    If you receive a UHID_FEATURE request you must answer with this request. You
>>    must copy the "id" field from the request into the answer. Set the "err" field
>> diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
>> index cedc6da..c5ee173 100644
>> --- a/drivers/hid/uhid.c
>> +++ b/drivers/hid/uhid.c
>> @@ -407,6 +407,69 @@ err_free:
>>         return ret;
>>  }
>>
>> +static int uhid_dev_create2(struct uhid_device *uhid,
>> +                           const struct uhid_event *ev)
>> +{
>> +       struct hid_device *hid;
>> +       int ret;
>> +
>> +       if (uhid->running)
>> +               return -EALREADY;
>> +
>> +       uhid->rd_size = ev->u.create2.rd_size;
>> +       if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE)
>> +               return -EINVAL;
>> +
>> +       uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL);
>> +       if (!uhid->rd_data)
>> +               return -ENOMEM;
>> +
>> +       memcpy(uhid->rd_data, ev->u.create2.rd_data, uhid->rd_size);
>
> Why don't we just use uhid_dev_create() and do this:
>
> if (ev->type == UHID_CREATE) {
>         ...copy_from_user()...
> } else if (ev->type == UHID_CREATE2) {
>         memcpy(...);
> }

This won't be enough. For UHID_CREATE, we need to use
ev->u.create.<member> and for UHID_CREATE2, ev->u.create2.<member>.
But, I'll collect those in local variables up front, so we can have
just one handler function. I'll send the revised diff shortly.

-- Petri

>
> This way we can avoid copying this whole function.
>
>> +
>> +       hid = hid_allocate_device();
>> +       if (IS_ERR(hid)) {
>> +               ret = PTR_ERR(hid);
>> +               goto err_free;
>> +       }
>> +
>> +       strncpy(hid->name, ev->u.create2.name, 127);
>> +       hid->name[127] = 0;
>> +       strncpy(hid->phys, ev->u.create2.phys, 63);
>> +       hid->phys[63] = 0;
>> +       strncpy(hid->uniq, ev->u.create2.uniq, 63);
>> +       hid->uniq[63] = 0;
>> +
>> +       hid->ll_driver = &uhid_hid_driver;
>> +       hid->hid_get_raw_report = uhid_hid_get_raw;
>> +       hid->hid_output_raw_report = uhid_hid_output_raw;
>> +       hid->bus = ev->u.create2.bus;
>> +       hid->vendor = ev->u.create2.vendor;
>> +       hid->product = ev->u.create2.product;
>> +       hid->version = ev->u.create2.version;
>> +       hid->country = ev->u.create2.country;
>> +       hid->driver_data = uhid;
>> +       hid->dev.parent = uhid_misc.this_device;
>> +
>> +       uhid->hid = hid;
>> +       uhid->running = true;
>> +
>> +       ret = hid_add_device(hid);
>> +       if (ret) {
>> +               hid_err(hid, "Cannot register HID device\n");
>> +               goto err_hid;
>> +       }
>> +
>> +       return 0;
>> +
>> +err_hid:
>> +       hid_destroy_device(hid);
>> +       uhid->hid = NULL;
>> +       uhid->running = false;
>> +err_free:
>> +       kfree(uhid->rd_data);
>> +       return ret;
>> +}
>> +
>>  static int uhid_dev_destroy(struct uhid_device *uhid)
>>  {
>>         if (!uhid->running)
>> @@ -435,6 +498,17 @@ static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
>>         return 0;
>>  }
>>
>> +static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
>> +{
>> +       if (!uhid->running)
>> +               return -EINVAL;
>> +
>> +       hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
>> +                        min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
>> +
>> +       return 0;
>> +}
>> +
>>  static int uhid_dev_feature_answer(struct uhid_device *uhid,
>>                                    struct uhid_event *ev)
>>  {
>> @@ -571,12 +645,18 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
>>         case UHID_CREATE:
>>                 ret = uhid_dev_create(uhid, &uhid->input_buf);
>>                 break;
>> +       case UHID_CREATE2:
>> +               ret = uhid_dev_create2(uhid, &uhid->input_buf);
>> +               break;
>>         case UHID_DESTROY:
>>                 ret = uhid_dev_destroy(uhid);
>>                 break;
>>         case UHID_INPUT:
>>                 ret = uhid_dev_input(uhid, &uhid->input_buf);
>>                 break;
>> +       case UHID_INPUT2:
>> +               ret = uhid_dev_input2(uhid, &uhid->input_buf);
>> +               break;
>>         case UHID_FEATURE_ANSWER:
>>                 ret = uhid_dev_feature_answer(uhid, &uhid->input_buf);
>>                 break;
>> diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h
>> index 414b74b..1e3b09c 100644
>> --- a/include/uapi/linux/uhid.h
>> +++ b/include/uapi/linux/uhid.h
>> @@ -21,6 +21,7 @@
>>
>>  #include <linux/input.h>
>>  #include <linux/types.h>
>> +#include <linux/hid.h>
>>
>>  enum uhid_event_type {
>>         UHID_CREATE,
>> @@ -34,6 +35,8 @@ enum uhid_event_type {
>>         UHID_INPUT,
>>         UHID_FEATURE,
>>         UHID_FEATURE_ANSWER,
>> +       UHID_CREATE2,
>> +       UHID_INPUT2,
>>  };
>>
>>  struct uhid_create_req {
>> @@ -50,6 +53,19 @@ struct uhid_create_req {
>>         __u32 country;
>>  } __attribute__((__packed__));
>>
>> +struct uhid_create2_req {
>> +       __u8 name[128];
>> +       __u8 phys[64];
>> +       __u8 uniq[64];
>> +       __u16 rd_size;
>> +       __u16 bus;
>> +       __u32 vendor;
>> +       __u32 product;
>> +       __u32 version;
>> +       __u32 country;
>> +       __u8 rd_data[HID_MAX_DESCRIPTOR_SIZE];
>> +} __attribute__((__packed__));
>> +
>>  #define UHID_DATA_MAX 4096
>>
>>  enum uhid_report_type {
>> @@ -63,6 +79,11 @@ struct uhid_input_req {
>>         __u16 size;
>>  } __attribute__((__packed__));
>>
>> +struct uhid_input2_req {
>> +       __u16 size;
>> +       __u8 data[UHID_DATA_MAX];
>> +} __attribute__((__packed__));
>> +
>>  struct uhid_output_req {
>>         __u8 data[UHID_DATA_MAX];
>>         __u16 size;
>> @@ -100,6 +121,8 @@ struct uhid_event {
>>                 struct uhid_output_ev_req output_ev;
>>                 struct uhid_feature_req feature;
>>                 struct uhid_feature_answer_req feature_answer;
>> +               struct uhid_create2_req create2;
>> +               struct uhid_input2_req input2;
>
> We change the size of uhid_output_req here, but I think that is fine.
> But you might wanna note that down in the commit-message.
>
> Patch looks fine. If you fix the minor issues, this is:
> Reviewed-by: David Herrmann <[e-mail]>
>
> And please always put Jiri on CC for all HID patches: "Jiri Kosina
> <[e-mail]>"
>
> Thanks
> David
>
>>         } u;
>>  } __attribute__((__packed__));
>>
>> --
>> 1.9.0.279.gdc9e3eb
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-input" in
>> the body of a message to [e-mail]
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
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David Herrmann March 24, 2014, 7:07 p.m. UTC | #4

Hi

On Mon, Mar 24, 2014 at 8:04 PM, Petri Gynther <[e-mail]> wrote:
> This won't be enough. For UHID_CREATE, we need to use
> ev->u.create.<member> and for UHID_CREATE2, ev->u.create2.<member>.
> But, I'll collect those in local variables up front, so we can have
> just one handler function. I'll send the revised diff shortly.

Oh right, In that case I think we can keep the two functions.

Thanks
David
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Petri Gynther March 24, 2014, 7:19 p.m. UTC | #5

Hi David,

On Mon, Mar 24, 2014 at 12:07 PM, David Herrmann <[e-mail]> wrote:
> Hi
>
> On Mon, Mar 24, 2014 at 8:04 PM, Petri Gynther <[e-mail]> wrote:
>> This won't be enough. For UHID_CREATE, we need to use
>> ev->u.create.<member> and for UHID_CREATE2, ev->u.create2.<member>.
>> But, I'll collect those in local variables up front, so we can have
>> just one handler function. I'll send the revised diff shortly.
>
> Oh right, In that case I think we can keep the two functions.

Agreed, I think we should keep the the two functions separate. So, is
the diff good as-is?

-- Petri

>
> Thanks
> David
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Patch

diff --git a/Documentation/hid/uhid.txt b/Documentation/hid/uhid.txt
index dc35a2b..ee65936 100644
--- a/Documentation/hid/uhid.txt
+++ b/Documentation/hid/uhid.txt
@@ -93,6 +93,11 @@  the request was handled successfully.
   event to the kernel. The payload is of type struct uhid_create_req and
   contains information about your device. You can start I/O now.
 
+  UHID_CREATE2:
+  Same as UHID_CREATE, but the HID report descriptor data (rd_data) is an array
+  inside struct uhid_create2_req, instead of a pointer to a separate array.
+  Enables use from languages that don't support pointers, e.g. Python.
+
   UHID_DESTROY:
   This destroys the internal HID device. No further I/O will be accepted. There
   may still be pending messages that you can receive with read() but no further
@@ -105,6 +110,12 @@  the request was handled successfully.
   contains a data-payload. This is the raw data that you read from your device.
   The kernel will parse the HID reports and react on it.
 
+  UHID_INPUT2:
+  Same as UHID_INPUT, but the data array is the last field of uhid_input2_req.
+  Enables userspace to write only the required bytes to kernel (ev.type +
+  ev.u.input2.size + the part of the data array that matters), instead of
+  the entire struct uhid_input2_req.
+
   UHID_FEATURE_ANSWER:
   If you receive a UHID_FEATURE request you must answer with this request. You
   must copy the "id" field from the request into the answer. Set the "err" field
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index cedc6da..c5ee173 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -407,6 +407,69 @@  err_free:
 	return ret;
 }
 
+static int uhid_dev_create2(struct uhid_device *uhid,
+			    const struct uhid_event *ev)
+{
+	struct hid_device *hid;
+	int ret;
+
+	if (uhid->running)
+		return -EALREADY;
+
+	uhid->rd_size = ev->u.create2.rd_size;
+	if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE)
+		return -EINVAL;
+
+	uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL);
+	if (!uhid->rd_data)
+		return -ENOMEM;
+
+	memcpy(uhid->rd_data, ev->u.create2.rd_data, uhid->rd_size);
+
+	hid = hid_allocate_device();
+	if (IS_ERR(hid)) {
+		ret = PTR_ERR(hid);
+		goto err_free;
+	}
+
+	strncpy(hid->name, ev->u.create2.name, 127);
+	hid->name[127] = 0;
+	strncpy(hid->phys, ev->u.create2.phys, 63);
+	hid->phys[63] = 0;
+	strncpy(hid->uniq, ev->u.create2.uniq, 63);
+	hid->uniq[63] = 0;
+
+	hid->ll_driver = &uhid_hid_driver;
+	hid->hid_get_raw_report = uhid_hid_get_raw;
+	hid->hid_output_raw_report = uhid_hid_output_raw;
+	hid->bus = ev->u.create2.bus;
+	hid->vendor = ev->u.create2.vendor;
+	hid->product = ev->u.create2.product;
+	hid->version = ev->u.create2.version;
+	hid->country = ev->u.create2.country;
+	hid->driver_data = uhid;
+	hid->dev.parent = uhid_misc.this_device;
+
+	uhid->hid = hid;
+	uhid->running = true;
+
+	ret = hid_add_device(hid);
+	if (ret) {
+		hid_err(hid, "Cannot register HID device\n");
+		goto err_hid;
+	}
+
+	return 0;
+
+err_hid:
+	hid_destroy_device(hid);
+	uhid->hid = NULL;
+	uhid->running = false;
+err_free:
+	kfree(uhid->rd_data);
+	return ret;
+}
+
 static int uhid_dev_destroy(struct uhid_device *uhid)
 {
 	if (!uhid->running)
@@ -435,6 +498,17 @@  static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
 	return 0;
 }
 
+static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
+{
+	if (!uhid->running)
+		return -EINVAL;
+
+	hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
+			 min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
+
+	return 0;
+}
+
 static int uhid_dev_feature_answer(struct uhid_device *uhid,
 				   struct uhid_event *ev)
 {
@@ -571,12 +645,18 @@  static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
 	case UHID_CREATE:
 		ret = uhid_dev_create(uhid, &uhid->input_buf);
 		break;
+	case UHID_CREATE2:
+		ret = uhid_dev_create2(uhid, &uhid->input_buf);
+		break;
 	case UHID_DESTROY:
 		ret = uhid_dev_destroy(uhid);
 		break;
 	case UHID_INPUT:
 		ret = uhid_dev_input(uhid, &uhid->input_buf);
 		break;
+	case UHID_INPUT2:
+		ret = uhid_dev_input2(uhid, &uhid->input_buf);
+		break;
 	case UHID_FEATURE_ANSWER:
 		ret = uhid_dev_feature_answer(uhid, &uhid->input_buf);
 		break;
diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h
index 414b74b..1e3b09c 100644
--- a/include/uapi/linux/uhid.h
+++ b/include/uapi/linux/uhid.h
@@ -21,6 +21,7 @@ 
 
 #include <linux/input.h>
 #include <linux/types.h>
+#include <linux/hid.h>
 
 enum uhid_event_type {
 	UHID_CREATE,
@@ -34,6 +35,8 @@  enum uhid_event_type {
 	UHID_INPUT,
 	UHID_FEATURE,
 	UHID_FEATURE_ANSWER,
+	UHID_CREATE2,
+	UHID_INPUT2,
 };
 
 struct uhid_create_req {
@@ -50,6 +53,19 @@  struct uhid_create_req {
 	__u32 country;
 } __attribute__((__packed__));
 
+struct uhid_create2_req {
+	__u8 name[128];
+	__u8 phys[64];
+	__u8 uniq[64];
+	__u16 rd_size;
+	__u16 bus;
+	__u32 vendor;
+	__u32 product;
+	__u32 version;
+	__u32 country;
+	__u8 rd_data[HID_MAX_DESCRIPTOR_SIZE];
+} __attribute__((__packed__));
+
 #define UHID_DATA_MAX 4096
 
 enum uhid_report_type {
@@ -63,6 +79,11 @@  struct uhid_input_req {
 	__u16 size;
 } __attribute__((__packed__));
 
+struct uhid_input2_req {
+	__u16 size;
+	__u8 data[UHID_DATA_MAX];
+} __attribute__((__packed__));
+
 struct uhid_output_req {
 	__u8 data[UHID_DATA_MAX];
 	__u16 size;
@@ -100,6 +121,8 @@  struct uhid_event {
 		struct uhid_output_ev_req output_ev;
 		struct uhid_feature_req feature;
 		struct uhid_feature_answer_req feature_answer;
+		struct uhid_create2_req create2;
+		struct uhid_input2_req input2;
 	} u;
 } __attribute__((__packed__));