firmware: enable to force disable the fallback mechanism at run time
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 45cc409..d6838e7 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;