Commit c8e85b4f authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds

posix timers: sigqueue_free: don't free sigqueue if it is queued

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: default avatarOleg Nesterov <oleg@tv-sign.ru>
Cc: Austin Clements <amdragon+kernelbugzilla@mit.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 84a88165
...@@ -1240,18 +1240,22 @@ void sigqueue_free(struct sigqueue *q) ...@@ -1240,18 +1240,22 @@ void sigqueue_free(struct sigqueue *q)
BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
/* /*
* If the signal is still pending remove it from the * We must hold ->siglock while testing q->list
* pending queue. We must hold ->siglock while testing * to serialize with collect_signal() or with
* q->list to serialize with collect_signal() or with
* __exit_signal()->flush_sigqueue(). * __exit_signal()->flush_sigqueue().
*/ */
spin_lock_irqsave(lock, flags); 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)) if (!list_empty(&q->list))
list_del_init(&q->list); q = NULL;
spin_unlock_irqrestore(lock, flags); spin_unlock_irqrestore(lock, flags);
q->flags &= ~SIGQUEUE_PREALLOC; if (q)
__sigqueue_free(q); __sigqueue_free(q);
} }
int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
......
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