Re: [PATCH 0/2] freezer,sched: do not restore saved_state of a thawed task

[Peter Zijlstra]

On Tue, Nov 28, 2023 at 05:12:00PM +0800, Aiqun(Maria) Yu wrote:
> On 11/21/2023 1:36 AM, Elliot Berman wrote:
> > This series applies couple fixes to commit 8f0eed4a78a8 ("freezer,sched:
> > Use saved_state to reduce some spurious wakeups") which was found while
> > testing with legacy cgroup freezer. My original testing was only with
> > system-wide freezer. We found that thaw_task could be called on a task
> > which was already frozen. Prior to commit 8f0eed4a78a8 ("freezer,sched:
> > Use saved_state to reduce some spurious wakeups"), this wasn't an issue
> > as kernel would try to wake up TASK_FROZEN, which wouldn't match the
> > thawed task state, and no harm done to task. After commit 8f0eed4a78a8
> > ("freezer,sched: Use saved_state to reduce some spurious wakeups"), it
> > was possible to overwrite the state of thawed task.
> > 
> > To: Rafael J. Wysocki <rafael@xxxxxxxxxx>
> > To: Pavel Machek <pavel@xxxxxx>
> > To: Ingo Molnar <mingo@xxxxxxxxxx>
> > To: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> > Cc:  <linux-arm-msm@xxxxxxxxxxxxxxx>
> > Cc: Pavan Kondeti <quic_pkondeti@xxxxxxxxxxx>
> > Cc: Aiqun Yu (Maria) <quic_aiquny@xxxxxxxxxxx>
> > Cc:  <linux-pm@xxxxxxxxxxxxxxx>
> > Cc:  <linux-kernel@xxxxxxxxxxxxxxx>
> > Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
> Shall we add Fixed tag and Cc: stable@xxxxxxxxxxxxxxx ?
> Since it is fixing a stable user thread hung issue.

If you want this routed through urgent, then yes.