diff options
| author | Bu, Yitian <ybu@qti.qualcomm.com> | 2013-02-18 12:53:37 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-04-14 06:44:16 -0700 |
| commit | aa34e62c2f0d4a105606971a1eb666f22338993b (patch) | |
| tree | 0dff0ab9129f77e0e510a1c82c29027751959313 /kernel/printk.c | |
| parent | 0df19efa7549d47aa906b8316665e46366b56061 (diff) | |
printk: Fix rq->lock vs logbuf_lock unlock lock inversion
commit dbda92d16f8655044e082930e4e9d244b87fde77 upstream.
commit 07354eb1a74d1 ("locking printk: Annotate logbuf_lock as raw")
reintroduced a lock inversion problem which was fixed in commit
0b5e1c5255 ("printk: Release console_sem after logbuf_lock"). This
happened probably when fixing up patch rejects.
Restore the ordering and unlock logbuf_lock before releasing
console_sem.
Signed-off-by: ybu <ybu@qti.qualcomm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Qiang Huang <h.huangqiang@huawei.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/printk.c')
| -rw-r--r-- | kernel/printk.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index e131c464f33..e39adc13f5f 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -822,9 +822,9 @@ static int console_trylock_for_printk(unsigned int cpu) } } printk_cpu = UINT_MAX; + raw_spin_unlock(&logbuf_lock); if (wake) up(&console_sem); - raw_spin_unlock(&logbuf_lock); return retval; } static const char recursion_bug_msg [] = |