* Sasha Levin <[email protected]> wrote:
> A random wakeup can get us out of sigsuspend() without TIF_SIGPENDING
> being set.
>
> Avoid that by making sure we were signaled, like sys_pause() does.
>
> Signed-off-by: Sasha Levin <[email protected]>
> ---
> kernel/signal.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/signal.c b/kernel/signal.c
> index 5da9180..3256c7e 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -3528,8 +3528,10 @@ static int sigsuspend(sigset_t *set)
> current->saved_sigmask = current->blocked;
> set_current_blocked(set);
>
> - __set_current_state(TASK_INTERRUPTIBLE);
> - schedule();
> + while (!signal_pending(current)) {
> + __set_current_state(TASK_INTERRUPTIBLE);
> + schedule();
> + }
> set_restore_sigmask();
> return -ERESTARTNOHAND;
> }
So this does not appear to be anything new, right?
I agree with the fix, but I'm somewhat worried about the potential ABI impact:
does anything exist out there that has learned to rely on spurious returns from
SyS_sigsuspend() or SyS_rt_sigsuspend() system calls? These are one of the most
frequently used system calls in signal based event loops.
Thanks,
Ingo
