Re: [PATCH 2/2] scsi: ufs: Protect PM ops and err_handler from user access through sysfs

From: Can Guo
Date: Mon Jan 04 2021 - 20:08:33 EST

On 2021-01-05 04:05, Bean Huo wrote:
On Sat, 2021-01-02 at 05:59 -0800, Can Guo wrote:
+ * @shutting_down: flag to check if shutdown has been invoked

I am not much sure if this flag is need, since once PM going in
shutdown path, what will be returnded by pm_runtime_get_sync()?

If pm_runtime_get_sync() will fail, just check its return.

That depends. During/after shutdown, for UFS's case only,
pm_runtime_get_sync(hba->dev) will most likely return 0,
because it is already RUNTIME_ACTIVE, pm_runtime_get_sync()
will directly return 0... meaning you cannot count on it.

Check Stanley's change -

Can Guo.

Hi Rafael
would you please help us confirm this?


+ * @host_sem: semaphore used to serialize concurrent contexts
* @eh_wq: Workqueue that eh_work works on
* @eh_work: Worker to handle UFS errors that require s/w attention
* @eeh_work: Worker to handle exception events
@@ -751,7 +753,8 @@ struct ufs_hba {
u32 intr_mask;
u16 ee_ctrl_mask;
bool is_powered;
- struct semaphore eh_sem;
+ bool shutting_down;
+ struct semaphore host_sem;