From: Li Zefan <lizf@cn.fujitsu.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Helsley <matthltc@us.ibm.com>,
Cedric Le Goater <clg@fr.ibm.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux Containers <containers@lists.linux-foundation.org>
Subject: [PATCH 1/4] freezer_cg: fix improper BUG_ON() causing oops
Date: Tue, 21 Oct 2008 08:48:53 +0800 [thread overview]
Message-ID: <48FD26F5.1070809@cn.fujitsu.com> (raw)
The BUG_ON() should be protected by freezer->lock, otherwise it
can be triggered easily when a task has been unfreezed but the
corresponding cgroup hasn't been changed to FROZEN state.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
kernel/cgroup_freezer.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index e950569..7f54d1c 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -190,8 +190,9 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task)
freezer = task_freezer(task);
task_unlock(task);
- BUG_ON(freezer->state == CGROUP_FROZEN);
spin_lock_irq(&freezer->lock);
+ BUG_ON(freezer->state == CGROUP_FROZEN);
+
/* Locking avoids race with FREEZING -> THAWED transitions. */
if (freezer->state == CGROUP_FREEZING)
freeze_task(task, true);
--
1.5.4.rc3
next reply other threads:[~2008-10-21 0:49 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-21 0:48 Li Zefan [this message]
2008-10-21 0:50 ` [PATCH 2/4] freezer_cg: remove redundant check in freezer_can_attach() Li Zefan
2008-10-21 0:51 ` [PATCH 3/4] freezer_cg: use thaw_process() in unfreeze_cgroup() Li Zefan
2008-10-21 0:52 ` [PATCH 4/4] freezer_cg: simplify freezer_change_state() Li Zefan
2008-10-21 9:53 ` Cedric Le Goater
2008-10-21 21:45 ` Matt Helsley
2008-10-21 7:16 ` [PATCH 3/4] freezer_cg: use thaw_process() in unfreeze_cgroup() Cedric Le Goater
2008-10-21 8:40 ` Li Zefan
2008-10-21 20:58 ` Andrew Morton
2008-10-22 7:37 ` Cedric Le Goater
2008-10-21 21:44 ` Matt Helsley
2008-10-21 7:32 ` [PATCH 2/4] freezer_cg: remove redundant check in freezer_can_attach() Cedric Le Goater
2008-10-21 9:29 ` Li Zefan
2008-10-21 9:47 ` Cedric Le Goater
2008-10-21 21:40 ` Matt Helsley
2008-10-21 7:16 ` [PATCH 1/4] freezer_cg: fix improper BUG_ON() causing oops Cedric Le Goater
2008-10-21 21:39 ` Matt Helsley
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