On 2020/09/22 19:13, Oliver Neukum wrote:
> +/* flush() is uninterruptible, but we cannot wait forever */
> +#define WDM_FLUSH_TIMEOUT (30 * HZ)
> static int wdm_flush(struct file *file, fl_owner_t id)
> {
> struct wdm_device *desc = file->private_data;
> + int rv;
>
> - wait_event(desc->wait,
> + rv = wait_event_timeout(desc->wait,
> /*
> * needs both flags. We cannot do with one
> * because resetting it would cause a race
> @@ -595,16 +630,25 @@ static int wdm_flush(struct file *file, fl_owner_t id)
> * a disconnect
> */
> !test_bit(WDM_IN_USE, &desc->flags) ||
> - test_bit(WDM_DISCONNECTING, &desc->flags));
> + test_bit(WDM_DISCONNECTING, &desc->flags),
> + WDM_FLUSH_TIMEOUT);
>
Generally looks OK.
Any chance we can use wait_event_killable_timeout() or wait_event_killable() here?
syzkaller sends SIGKILL after 5 seconds from process creation. Blocking for 30
seconds in TASK_UNINTERRUPTIBLE state is not happy when killed by e.g. OOM killer.
