On Sun, Apr 10, 2022 at 12:42:24AM +0100, Qais Yousef wrote: > +CC stable > > On 01/20/22 16:25, Valentin Schneider wrote: > > TASK_RTLOCK_WAIT currently isn't part of TASK_REPORT, thus a task blocking > > on an rtlock will appear as having a task state == 0, IOW TASK_RUNNING. > > > > The actual state is saved in p->saved_state, but reading it after reading > > p->__state has a few issues: > > o that could still be TASK_RUNNING in the case of e.g. rt_spin_lock > > o ttwu_state_match() might have changed that to TASK_RUNNING > > > > As pointed out by Eric, adding TASK_RTLOCK_WAIT to TASK_REPORT implies > > exposing a new state to userspace tools which way not know what to do with > > them. The only information that needs to be conveyed here is that a task is > > waiting on an rt_mutex, which matches TASK_UNINTERRUPTIBLE - there's no > > need for a new state. > > > > Reported-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > > Signed-off-by: Valentin Schneider <valentin.schneider@xxxxxxx> > > Any objection for this to be picked up by stable? We care about Patch 1 only in > this series for stable, but it seems sensible to pick this one too, no strong > feeling if it is omitted though. > > AFAICT it seems the problem dates back since commit: > > 1593baab910d ("sched/debug: Implement consistent task-state printing") > > or even before. I think v4.14+ is good enough. <formletter> This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly. </formletter>