From 193191035ad6268db9f561e81e3474b8be89a5ba Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Wed, 30 Apr 2008 00:53:02 -0700
Subject: [PATCH] signals: check_kill_permission: remove tasklist_lock

Now that task_session() can't return a false NULL, check_kill_permission()
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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 kernel/signal.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 24be82c0aae3..02ef3548aeb0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -551,9 +551,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
 	    !capable(CAP_KILL)) {
 		switch (sig) {
 		case SIGCONT:
-			read_lock(&tasklist_lock);
 			sid = task_session(t);
-			read_unlock(&tasklist_lock);
 			/*
 			 * We don't return the error if sid == NULL. The
 			 * task was unhashed, the caller must notice this.