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>
This commit is contained in:
Luis R. Rodriguez 2018-03-10 06:14:52 -08:00 committed by Greg Kroah-Hartman
parent ceb1813224
commit 2cd7a1c6dc
3 changed files with 18 additions and 0 deletions

View File

@ -643,6 +643,11 @@ static bool fw_force_sysfs_fallback(unsigned int opt_flags)
static bool fw_run_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)) if ((opt_flags & FW_OPT_NOFALLBACK))
return false; return false;

View File

@ -14,12 +14,16 @@
* as if one had enabled CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y. * as if one had enabled CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y.
* Useful to help debug a 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. * 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 * @old_timeout: for internal use
* @loading_timeout: the timeout to wait for the fallback mechanism before * @loading_timeout: the timeout to wait for the fallback mechanism before
* giving up, in seconds. * giving up, in seconds.
*/ */
struct firmware_fallback_config { struct firmware_fallback_config {
unsigned int force_sysfs_fallback; unsigned int force_sysfs_fallback;
unsigned int ignore_sysfs_fallback;
int old_timeout; int old_timeout;
int loading_timeout; int loading_timeout;
}; };

View File

@ -39,6 +39,15 @@ struct ctl_table firmware_config_table[] = {
.extra1 = &zero, .extra1 = &zero,
.extra2 = &one, .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); EXPORT_SYMBOL_GPL(firmware_config_table);