Hi Mark,
On 5/25/23 21:31, Mark Pearson wrote:
> Add mutex protection around cases where an operation needs multiple
> WMI calls - e.g. setting password.
>
> Signed-off-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
> ---
> Changes in V2: New commit added after review of other patches in series.
>
> drivers/platform/x86/think-lmi.c | 46 ++++++++++++++++++++++++--------
> 1 file changed, 35 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
> index 64cd453d6e7d..f3e1e4dacba2 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 */
> @@ -463,23 +465,32 @@ static ssize_t new_password_store(struct kobject *kobj,
> sprintf(pwd_type, "%s", setting->pwd_type);
> }
>
> + mutex_lock(&tlmi_mutex);
> ret = tlmi_opcode_setting("WmiOpcodePasswordType", pwd_type);
> - if (ret)
> + if (ret) {
> + mutex_unlock(&tlmi_mutex);
> goto out;
> -
> + }
> if (tlmi_priv.pwd_admin->valid) {
> ret = tlmi_opcode_setting("WmiOpcodePasswordAdmin",
> tlmi_priv.pwd_admin->password);
> - if (ret)
> + if (ret) {
> + mutex_unlock(&tlmi_mutex);
> goto out;
> + }
> }
> ret = tlmi_opcode_setting("WmiOpcodePasswordCurrent01", setting->password);
> - if (ret)
> + if (ret) {
> + mutex_unlock(&tlmi_mutex);
> goto out;
> + }
> ret = tlmi_opcode_setting("WmiOpcodePasswordNew01", new_pwd);
> - if (ret)
> + if (ret) {
> + mutex_unlock(&tlmi_mutex);
> goto out;
> + }
> ret = tlmi_simple_call(LENOVO_OPCODE_IF_GUID, "WmiOpcodePasswordSetUpdate;");
> + mutex_unlock(&tlmi_mutex);
> } else {
> /* Format: 'PasswordType,CurrentPw,NewPw,Encoding,KbdLang;' */
> auth_str = kasprintf(GFP_KERNEL, "%s,%s,%s,%s,%s;",
I haven't take a really close / good look yet. But at a first glance
I think it would be cleaner to just take the mutex at the top
and unlock it after the out label to which all the existing goto-s
already go ?
> @@ -1000,11 +1011,16 @@ static ssize_t current_value_store(struct kobject *kobj,
> goto out;
> }
>
> + mutex_lock(&tlmi_mutex);
> ret = tlmi_simple_call(LENOVO_SET_BIOS_SETTING_CERT_GUID, set_str);
> - if (ret)
> + if (ret) {
> + mutex_unlock(&tlmi_mutex);
> goto out;
> + }
> ret = tlmi_simple_call(LENOVO_SAVE_BIOS_SETTING_CERT_GUID,
> tlmi_priv.pwd_admin->save_signature);
> +
> + mutex_unlock(&tlmi_mutex);
> if (ret)
> goto out;
> } else if (tlmi_priv.opcode_support) {
> @@ -1021,18 +1037,23 @@ static ssize_t current_value_store(struct kobject *kobj,
> goto out;
> }
>
> + mutex_lock(&tlmi_mutex);
> ret = tlmi_simple_call(LENOVO_SET_BIOS_SETTINGS_GUID, set_str);
> - if (ret)
> + if (ret) {
> + mutex_unlock(&tlmi_mutex);
> goto out;
> + }
>
> if (tlmi_priv.pwd_admin->valid && tlmi_priv.pwd_admin->password[0]) {
> ret = tlmi_opcode_setting("WmiOpcodePasswordAdmin",
> tlmi_priv.pwd_admin->password);
> - if (ret)
> + if (ret) {
> + mutex_unlock(&tlmi_mutex);
> goto out;
> + }
> }
> -
> ret = tlmi_save_bios_settings("");
> + mutex_unlock(&tlmi_mutex);
> } else { /* old non opcode based authentication method (deprecated)*/
> if (tlmi_priv.pwd_admin->valid && tlmi_priv.pwd_admin->password[0]) {
> auth_str = kasprintf(GFP_KERNEL, "%s,%s,%s;",
> @@ -1056,14 +1077,17 @@ static ssize_t current_value_store(struct kobject *kobj,
> goto out;
> }
>
> + mutex_lock(&tlmi_mutex);
> ret = tlmi_simple_call(LENOVO_SET_BIOS_SETTINGS_GUID, set_str);
> - if (ret)
> + if (ret) {
> + mutex_unlock(&tlmi_mutex);
> goto out;
> -
> + }
> if (auth_str)
> ret = tlmi_save_bios_settings(auth_str);
> else
> ret = tlmi_save_bios_settings("");
> + mutex_unlock(&tlmi_mutex);
> }
> if (!ret && !tlmi_priv.pending_changes) {
> tlmi_priv.pending_changes = true;
And the same here.
Regards,
Hans
