Messages in this thread Patch in this message | | | Date | Mon, 26 May 2008 20:55:42 +0400 | From | Oleg Nesterov <> | Subject | [PATCH 1/2] posix timers: sigqueue_free: don't free sigqueue if it is queued |
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Currently sigqueue_free() removes sigqueue from list, but doesn't cancel the pending signal. This is not consistent, the task should either receive the "full" signal along with siginfo_t, or it shouldn't receive the signal at all.
Change sigqueue_free() to clear SIGQUEUE_PREALLOC but leave sigqueue on list if it is queued.
This is a user-visible change. If the signal is blocked, it stays queued after sys_timer_delete() until unblocked with the "stale" si_code/si_value, and of course it is still counted wrt RLIMIT_SIGPENDING which also limits the number of posix timers.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
--- 26-rc2/kernel/signal.c~1_SF_DONT_REMOVE 2008-05-26 18:09:12.000000000 +0400 +++ 26-rc2/kernel/signal.c 2008-05-26 18:13:08.000000000 +0400 @@ -1240,18 +1240,22 @@ void sigqueue_free(struct sigqueue *q) BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); /* - * If the signal is still pending remove it from the - * pending queue. We must hold ->siglock while testing - * q->list to serialize with collect_signal() or with + * We must hold ->siglock while testing q->list + * to serialize with collect_signal() or with * __exit_signal()->flush_sigqueue(). */ spin_lock_irqsave(lock, flags); + q->flags &= ~SIGQUEUE_PREALLOC; + /* + * If it is queued it will be freed when dequeued, + * like the "regular" sigqueue. + */ if (!list_empty(&q->list)) - list_del_init(&q->list); + q = NULL; spin_unlock_irqrestore(lock, flags); - q->flags &= ~SIGQUEUE_PREALLOC; - __sigqueue_free(q); + if (q) + __sigqueue_free(q); } int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
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