The patch titled
signals: dequeue_signal: don't check SIGNAL_GROUP_EXIT when setting SIGNAL_STOP_DEQUEUED
has been added to the -mm tree. Its filename is
signals-dequeue_signal-dont-check-signal_group_exit-when-setting-signal_stop_dequeued.patch
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------------------------------------------------------
Subject: signals: dequeue_signal: don't check SIGNAL_GROUP_EXIT when setting SIGNAL_STOP_DEQUEUED
From: Oleg Nesterov <oleg@xxxxxxxxxx>
dequeue_signal() checks SIGNAL_GROUP_EXIT before setting
SIGNAL_STOP_DEQUEUED. This was added by
788e05a67c343fa22f2ae1d3ca264e7f15c25eaf a long ago to avoid the
coredump/SIGSTOP race.
Since then the related code was changed, and now this subtle check is both
incomplete and unneeded at the same time. It is incomplete because
nowadays exec() doesn't set SIGNAL_GROUP_EXIT, so in fact we should check
signal_group_exit() to avoid a similar race. Fortunately, we doesn't need
the check at all. The only function which relies on SIGNAL_STOP_DEQUEUED
is do_signal_stop(), and it ignores this flag if signal_group_exit() == T,
this covers the SIGNAL_GROUP_EXIT case.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/signal.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff -puN kernel/signal.c~signals-dequeue_signal-dont-check-signal_group_exit-when-setting-signal_stop_dequeued kernel/signal.c
--- a/kernel/signal.c~signals-dequeue_signal-dont-check-signal_group_exit-when-setting-signal_stop_dequeued
+++ a/kernel/signal.c
@@ -454,8 +454,7 @@ int dequeue_signal(struct task_struct *t
* is to alert stop-signal processing code when another
* processor has come along and cleared the flag.
*/
- if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
- tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
+ tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
}
if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) {
/*
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
vt-fix-vc_resize-locking.patch
uml-activate_mm-remove-the-dead-pf_borrowed_mm-check.patch
posix-timers-timer_delete-remove-the-bogus-it_process-=-null-check.patch
posix-timers-release_posix_timer-kill-the-bogus-put_task_struct-it_process.patch
signals-collect_signal-remove-the-unneeded-sigismember-check.patch
signals-collect_signal-simplify-the-still_pending-logic.patch
signals-change-collect_signal-to-return-void.patch
__exit_signal-dont-take-rcu-lock.patch
signals-dequeue_signal-dont-check-signal_group_exit-when-setting-signal_stop_dequeued.patch
signals-do_signal_stop-kill-the-signal_unkillable-check.patch
coredump-zap_threads-comments-use-while_each_thread.patch
distinct-tgid-tid-i-o-statistics.patch
--
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