lkml.org 
[lkml]   [2011]   [Aug]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH pm-freezer 4/4] freezer: use lock_task_sighand() in fake_signal_wake_up()
cgroup_freezer calls freeze_task() without holding tasklist_lock and,
if the task is exiting, its ->sighand may be gone by the time
fake_signal_wake_up() is called. Use lock_task_sighand() instead of
accessing ->sighand directly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Paul Menage <paul@paulmenage.org>
---
kernel/freezer.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

Index: work/kernel/freezer.c
===================================================================
--- work.orig/kernel/freezer.c
+++ work/kernel/freezer.c
@@ -103,9 +103,10 @@ static void fake_signal_wake_up(struct t
{
unsigned long flags;

- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, 0);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ if (lock_task_sighand(p, &flags)) {
+ signal_wake_up(p, 0);
+ unlock_task_sighand(p, &flags);
+ }
}

/**

\
 
 \ /
  Last update: 2011-08-29 16:09    [W:0.077 / U:1.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site