From: Oleg Nesterov <oleg@tv-sign.ru>

handle_stop_signal() was changed, now send_group_sigqueue() doesn't need
tasklist_lock.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/signal.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff -puN kernel/signal.c~signals-send_group_sigqueue-dont-take-tasklist_lock kernel/signal.c
--- a/kernel/signal.c~signals-send_group_sigqueue-dont-take-tasklist_lock
+++ a/kernel/signal.c
@@ -1335,7 +1335,6 @@ send_group_sigqueue(int sig, struct sigq
 
 	BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
 
-	read_lock(&tasklist_lock);
 	/* Since it_lock is held, p->sighand cannot be NULL. */
 	spin_lock_irqsave(&p->sighand->siglock, flags);
 
@@ -1344,7 +1343,7 @@ send_group_sigqueue(int sig, struct sigq
 	__group_complete_signal(sig, p);
 
 	spin_unlock_irqrestore(&p->sighand->siglock, flags);
-	read_unlock(&tasklist_lock);
+
 	return ret;
 }
 
_