diff mbox

[v3,11/20] firmware: enable to force disable the fallback mechanism at run time

Message ID 20180310141501.2214-12-mcgrof@kernel.org
State New, archived
Headers show

Commit Message

Luis Chamberlain March 10, 2018, 2:14 p.m. UTC
You currently need four different kernel builds to test the firmware
API fully. By adding a proc knob to force disable the fallback mechanism
completely we are able to reduce the amount of kernels you need built
to test the firmware API down to two.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/firmware_loader/fallback.c       | 5 +++++
 drivers/base/firmware_loader/fallback.h       | 4 ++++
 drivers/base/firmware_loader/fallback_table.c | 9 +++++++++
 3 files changed, 18 insertions(+)

Comments

Greg Kroah-Hartman March 14, 2018, 7 p.m. UTC | #1
On Sat, Mar 10, 2018 at 06:14:52AM -0800, Luis R. Rodriguez wrote:
> You currently need four different kernel builds to test the firmware
> API fully. By adding a proc knob to force disable the fallback mechanism
> completely we are able to reduce the amount of kernels you need built
> to test the firmware API down to two.
> 
> Acked-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> ---
>  drivers/base/firmware_loader/fallback.c       | 5 +++++
>  drivers/base/firmware_loader/fallback.h       | 4 ++++
>  drivers/base/firmware_loader/fallback_table.c | 9 +++++++++
>  3 files changed, 18 insertions(+)
> 
> diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
> index 45cc40933a47..d6838e7ec00c 100644
> --- a/drivers/base/firmware_loader/fallback.c
> +++ b/drivers/base/firmware_loader/fallback.c
> @@ -643,6 +643,11 @@ static bool fw_force_sysfs_fallback(unsigned int opt_flags)
>  
>  static bool fw_run_sysfs_fallback(unsigned int opt_flags)
>  {
> +	if (fw_fallback_config.ignore_sysfs_fallback) {
> +		pr_info_once("Ignoring firmware sysfs fallback due to debugfs knob\n");

s/debugfs/sysctl/ right?
Luis Chamberlain March 18, 2018, 8:20 p.m. UTC | #2
On Wed, Mar 14, 2018 at 12:00 PM, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Sat, Mar 10, 2018 at 06:14:52AM -0800, Luis R. Rodriguez wrote:
>> You currently need four different kernel builds to test the firmware
>> API fully. By adding a proc knob to force disable the fallback mechanism
>> completely we are able to reduce the amount of kernels you need built
>> to test the firmware API down to two.
>>
>> Acked-by: Kees Cook <keescook@chromium.org>
>> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
>> ---
>>  drivers/base/firmware_loader/fallback.c       | 5 +++++
>>  drivers/base/firmware_loader/fallback.h       | 4 ++++
>>  drivers/base/firmware_loader/fallback_table.c | 9 +++++++++
>>  3 files changed, 18 insertions(+)
>>
>> diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
>> index 45cc40933a47..d6838e7ec00c 100644
>> --- a/drivers/base/firmware_loader/fallback.c
>> +++ b/drivers/base/firmware_loader/fallback.c
>> @@ -643,6 +643,11 @@ static bool fw_force_sysfs_fallback(unsigned int opt_flags)
>>
>>  static bool fw_run_sysfs_fallback(unsigned int opt_flags)
>>  {
>> +     if (fw_fallback_config.ignore_sysfs_fallback) {
>> +             pr_info_once("Ignoring firmware sysfs fallback due to debugfs knob\n");
>
> s/debugfs/sysctl/ right?

Indeed. Will respin with the other space fix. As for the other changes
let me know if you have further feedback or if I should just keep them
as-is.

  Luis
diff mbox

Patch

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 45cc40933a47..d6838e7ec00c 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -643,6 +643,11 @@  static bool fw_force_sysfs_fallback(unsigned int opt_flags)
 
 static bool fw_run_sysfs_fallback(unsigned int opt_flags)
 {
+	if (fw_fallback_config.ignore_sysfs_fallback) {
+		pr_info_once("Ignoring firmware sysfs fallback due to debugfs knob\n");
+		return false;
+	}
+
 	if ((opt_flags & FW_OPT_NOFALLBACK))
 		return false;
 
diff --git a/drivers/base/firmware_loader/fallback.h b/drivers/base/firmware_loader/fallback.h
index ca7e69a8417b..dfebc644ed35 100644
--- a/drivers/base/firmware_loader/fallback.h
+++ b/drivers/base/firmware_loader/fallback.h
@@ -14,12 +14,16 @@ 
  * 	as if one had enabled CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y.
  * 	Useful to help debug a CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y
  * 	functionality on a kernel where that config entry has been disabled.
+ * @ignore_sysfs_fallback: force to disable the sysfs fallback mechanism.
+ * 	This emulates the behaviour as if we had set the kernel
+ * 	config CONFIG_FW_LOADER_USER_HELPER=n.
  * @old_timeout: for internal use
  * @loading_timeout: the timeout to wait for the fallback mechanism before
  * 	giving up, in seconds.
  */
 struct firmware_fallback_config {
 	unsigned int force_sysfs_fallback;
+	unsigned int ignore_sysfs_fallback;
 	int old_timeout;
 	int loading_timeout;
 };
diff --git a/drivers/base/firmware_loader/fallback_table.c b/drivers/base/firmware_loader/fallback_table.c
index 92365e053e30..7428659d8df9 100644
--- a/drivers/base/firmware_loader/fallback_table.c
+++ b/drivers/base/firmware_loader/fallback_table.c
@@ -39,6 +39,15 @@  struct ctl_table firmware_config_table[] = {
 		.extra1		= &zero,
 		.extra2		= &one,
 	},
+	{
+		.procname	= "ignore_sysfs_fallback",
+		.data		= &fw_fallback_config.ignore_sysfs_fallback,
+		.maxlen         = sizeof(unsigned int),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &one,
+	},
 	{ }
 };
 EXPORT_SYMBOL_GPL(firmware_config_table);