From: Tejun Heo <tj@kernel.org>
To: rjw@sisk.pl, paul@paulmenage.org, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org
Cc: arnd@arndb.de, oleg@redhat.com, matthltc@us.ibm.com
Subject: [PATCH 19/17] freezer: use lock_task_sighand() in fake_signal_wake_up()
Date: Mon, 31 Oct 2011 15:35:26 -0700 [thread overview]
Message-ID: <20111031223526.GE18855@google.com> (raw)
In-Reply-To: <1320087928-32307-1-git-send-email-tj@kernel.org>
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>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Paul Menage <paul@paulmenage.org>
---
kernel/freezer.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 10f9840..a9c18c7 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -93,9 +93,10 @@ static void fake_signal_wake_up(struct task_struct *p)
{
unsigned long flags;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, 1);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ if (lock_task_sighand(p, &flags)) {
+ signal_wake_up(p, 1);
+ unlock_task_sighand(p, &flags);
+ }
}
/**
--
1.7.3.1
next prev parent reply other threads:[~2011-10-31 22:35 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-31 19:05 [PATCHSET pm] freezer: fix various bugs and simplify implementation, take#2 Tejun Heo
2011-10-31 19:05 ` [PATCH 01/17] freezer: fix current->state restoration race in refrigerator() Tejun Heo
2011-10-31 19:05 ` [PATCH 02/17] freezer: don't unnecessarily set PF_NOFREEZE explicitly Tejun Heo
2011-10-31 19:05 ` [PATCH 03/17] freezer: unexport refrigerator() and update try_to_freeze() slightly Tejun Heo
2011-10-31 19:05 ` [PATCH 04/17] freezer: implement and use kthread_freezable_should_stop() Tejun Heo
2011-10-31 19:05 ` [PATCH 05/17] freezer: rename thaw_process() to __thaw_task() and simplify the implementation Tejun Heo
2011-11-06 12:04 ` Srivatsa S. Bhat
2011-11-06 16:51 ` Tejun Heo
2011-11-06 17:10 ` Srivatsa S. Bhat
2011-10-31 19:05 ` [PATCH 06/17] freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks Tejun Heo
2011-10-31 19:05 ` [PATCH 07/17] freezer: don't distinguish nosig tasks on thaw Tejun Heo
2011-10-31 19:05 ` [PATCH 08/17] freezer: use dedicated lock instead of task_lock() + memory barrier Tejun Heo
2011-10-31 19:05 ` [PATCH 09/17] freezer: make freezing indicate freeze condition in effect Tejun Heo
2011-10-31 19:05 ` [PATCH 10/17] freezer: test freezable conditions while holding freezer_lock Tejun Heo
2011-10-31 19:05 ` [PATCH 11/17] freezer: kill PF_FREEZING Tejun Heo
2011-10-31 19:05 ` [PATCH 12/17] freezer: clean up freeze_processes() failure path Tejun Heo
2011-11-03 19:09 ` Srivatsa S. Bhat
2011-11-03 22:25 ` [PATCH UPDATED " Tejun Heo
2011-10-31 19:05 ` [PATCH 13/17] cgroup_freezer: prepare for removal of TIF_FREEZE Tejun Heo
2011-10-31 22:33 ` [PATCH UPDATED " Tejun Heo
2011-10-31 19:05 ` [PATCH 14/17] freezer: make freezing() test freeze conditions in effect instead " Tejun Heo
2011-10-31 22:34 ` [PATCH UPDATED " Tejun Heo
2011-10-31 19:05 ` [PATCH 15/17] freezer: remove now unused TIF_FREEZE Tejun Heo
2011-10-31 19:05 ` [PATCH 16/17] freezer: remove should_send_signal() and update frozen() Tejun Heo
2011-10-31 19:05 ` [PATCH 17/17] freezer: fix set_freezable[_with_signal]() race Tejun Heo
2011-10-31 22:34 ` [PATCH 18/17] freezer: restructure __refrigerator() Tejun Heo
2011-10-31 22:35 ` Tejun Heo [this message]
2011-10-31 22:35 ` [PATCH UPDATED 20/17] freezer: remove unused @sig_only from freeze_task() Tejun Heo
2011-10-31 22:40 ` [PATCHSET UPDATED pm] freezer: fix various bugs and simplify implementation, take#2 Tejun Heo
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