The patch titled
signals: sigqueue_free: don't free sigqueue if it is queued
has been added to the -mm tree. Its filename is
signals-sigqueue_free-dont-free-sigqueue-if-it-is-queued.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: signals: sigqueue_free: don't free sigqueue if it is queued
From: Oleg Nesterov <oleg@xxxxxxxxxx>
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 patch doesn't change the behaviour of sys_timer_delete() and friends,
just makes it more correct and allows us to introduce other SIGQUEUE_
flags passed to the receiver.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/signal.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff -puN kernel/signal.c~signals-sigqueue_free-dont-free-sigqueue-if-it-is-queued kernel/signal.c
--- a/kernel/signal.c~signals-sigqueue_free-dont-free-sigqueue-if-it-is-queued
+++ a/kernel/signal.c
@@ -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)
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
signals-fix-sigqueue_free-vs-__exit_signal-race.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-sigqueue_free-dont-free-sigqueue-if-it-is-queued.patch
signals-introduce-sigqueue_cancelled.patch
posix-timers-use-sigqueue_cancelled-when-the-timer-is-destroyed.patch
put_pid-make-sure-we-dont-free-the-live-pid.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
