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    SubjectRe: [PATCH 1/3] signals: Allow generation of SIGKILL to exiting task.
    Andrey Grodzovsky <andrey.grodzovsky@amd.com> writes:

    > Currently calling wait_event_killable as part of exiting process
    > will stall forever since SIGKILL generation is suppresed by PF_EXITING.
    >
    > In our partilaur case AMDGPU driver wants to flush all GPU jobs in
    > flight before shutting down. But if some job hangs the pipe we still want to
    > be able to kill it and avoid a process in D state.

    I should clarify. This absolutely can not be done.
    PF_EXITING is set just before a task starts tearing down it's signal
    handling.

    So delivering any signal, or otherwise depending on signal handling
    after PF_EXITING is set can not be done. That abstraction is gone.

    Eric

    > Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
    > ---
    > kernel/signal.c | 4 ++--
    > 1 file changed, 2 insertions(+), 2 deletions(-)
    >
    > diff --git a/kernel/signal.c b/kernel/signal.c
    > index c6e4c83..c49c706 100644
    > --- a/kernel/signal.c
    > +++ b/kernel/signal.c
    > @@ -886,10 +886,10 @@ static inline int wants_signal(int sig, struct task_struct *p)
    > {
    > if (sigismember(&p->blocked, sig))
    > return 0;
    > - if (p->flags & PF_EXITING)
    > - return 0;
    > if (sig == SIGKILL)
    > return 1;
    > + if (p->flags & PF_EXITING)
    > + return 0;
    > if (task_is_stopped_or_traced(p))
    > return 0;
    > return task_curr(p) || !signal_pending(p);

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