diff mbox

[v2,09/11] firmware: enable to force disable the fallback mechanism at run time

Message ID 20180224024613.24078-10-mcgrof@kernel.org
State New, archived
Headers show

Commit Message

Luis Chamberlain Feb. 24, 2018, 2:46 a.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.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/firmware_fallback.c       | 5 +++++
 drivers/base/firmware_fallback.h       | 4 ++++
 drivers/base/firmware_fallback_table.c | 9 +++++++++
 3 files changed, 18 insertions(+)

Comments

Kees Cook Feb. 27, 2018, 11:23 p.m. UTC | #1
On Fri, Feb 23, 2018 at 6:46 PM, Luis R. Rodriguez <mcgrof@kernel.org> 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.
>
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/base/firmware_fallback.c       | 5 +++++
>  drivers/base/firmware_fallback.h       | 4 ++++
>  drivers/base/firmware_fallback_table.c | 9 +++++++++
>  3 files changed, 18 insertions(+)
>
> diff --git a/drivers/base/firmware_fallback.c b/drivers/base/firmware_fallback.c
> index cbce9a950cd8..13fa5ff2b46c 100644
> --- a/drivers/base/firmware_fallback.c
> +++ b/drivers/base/firmware_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_fallback.h b/drivers/base/firmware_fallback.h
> index ca7e69a8417b..dfebc644ed35 100644
> --- a/drivers/base/firmware_fallback.h
> +++ b/drivers/base/firmware_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_fallback_table.c b/drivers/base/firmware_fallback_table.c
> index 77300d5e9c52..5e990b0330c7 100644
> --- a/drivers/base/firmware_fallback_table.c
> +++ b/drivers/base/firmware_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);
> --
> 2.16.2
>
diff mbox

Patch

diff --git a/drivers/base/firmware_fallback.c b/drivers/base/firmware_fallback.c
index cbce9a950cd8..13fa5ff2b46c 100644
--- a/drivers/base/firmware_fallback.c
+++ b/drivers/base/firmware_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_fallback.h b/drivers/base/firmware_fallback.h
index ca7e69a8417b..dfebc644ed35 100644
--- a/drivers/base/firmware_fallback.h
+++ b/drivers/base/firmware_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_fallback_table.c b/drivers/base/firmware_fallback_table.c
index 77300d5e9c52..5e990b0330c7 100644
--- a/drivers/base/firmware_fallback_table.c
+++ b/drivers/base/firmware_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);