Hi,
On 6/1/23 22:05, Mark Pearson wrote:
> When an attribute is being changed if the Admin account is enabled, or if a password
> is being updated then multiple WMI calls are needed.
> Add mutex protection to ensure no race conditions are introduced.
>
> Fixes: b49f72e7f96d ("platform/x86: think-lmi: Certificate authentication support")
> Signed-off-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
Thank you for your patch-series, I've applied the series to my
review-hans branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans
Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.
Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.
Regards,
Hans
> ---
> Changes in v2:
> - New commit added after review of other patches in series.
> Changes in v3:
> - Simplified mutex handling as recommended.
> Changes in v4:
> - This was the 5th patch in the series but moved to be first.
> - Added Fixes tag.
> - Improved commit information to be clearer.
>
> drivers/platform/x86/think-lmi.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
> index 1138f770149d..6cf77bc26b05 100644
> --- a/drivers/platform/x86/think-lmi.c
> +++ b/drivers/platform/x86/think-lmi.c
> @@ -14,6 +14,7 @@
> #include <linux/acpi.h>
> #include <linux/errno.h>
> #include <linux/fs.h>
> +#include <linux/mutex.h>
> #include <linux/string.h>
> #include <linux/types.h>
> #include <linux/dmi.h>
> @@ -195,6 +196,7 @@ static const char * const level_options[] = {
> };
> static struct think_lmi tlmi_priv;
> static struct class *fw_attr_class;
> +static DEFINE_MUTEX(tlmi_mutex);
>
> /* ------ Utility functions ------------*/
> /* Strip out CR if one is present */
> @@ -437,6 +439,9 @@ static ssize_t new_password_store(struct kobject *kobj,
> /* Strip out CR if one is present, setting password won't work if it is present */
> strip_cr(new_pwd);
>
> + /* Use lock in case multiple WMI operations needed */
> + mutex_lock(&tlmi_mutex);
> +
> pwdlen = strlen(new_pwd);
> /* pwdlen == 0 is allowed to clear the password */
> if (pwdlen && ((pwdlen < setting->minlen) || (pwdlen > setting->maxlen))) {
> @@ -493,6 +498,7 @@ static ssize_t new_password_store(struct kobject *kobj,
> kfree(auth_str);
> }
> out:
> + mutex_unlock(&tlmi_mutex);
> kfree(new_pwd);
> return ret ?: count;
> }
> @@ -981,6 +987,9 @@ static ssize_t current_value_store(struct kobject *kobj,
> /* Strip out CR if one is present */
> strip_cr(new_setting);
>
> + /* Use lock in case multiple WMI operations needed */
> + mutex_lock(&tlmi_mutex);
> +
> /* Check if certificate authentication is enabled and active */
> if (tlmi_priv.certificate_support && tlmi_priv.pwd_admin->cert_installed) {
> if (!tlmi_priv.pwd_admin->signature || !tlmi_priv.pwd_admin->save_signature) {
> @@ -1039,6 +1048,7 @@ static ssize_t current_value_store(struct kobject *kobj,
> kobject_uevent(&tlmi_priv.class_dev->kobj, KOBJ_CHANGE);
> }
> out:
> + mutex_unlock(&tlmi_mutex);
> kfree(auth_str);
> kfree(set_str);
> kfree(new_setting);
