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| author | Bu, Yitian <ybu@qti.qualcomm.com> | 2013-02-18 12:53:37 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-25 14:07:31 -0700 |
| commit | 5df5df87f2b5f5d75825207d61a272b168d8cab6 (patch) | |
| tree | 9909ae74a18000317fd1e4889fd9e67b36376442 | |
| parent | bcaef288b2a3187de17220e86e15b762b3b0808e (diff) | |
| download | lwn-5df5df87f2b5f5d75825207d61a272b168d8cab6.tar.gz lwn-5df5df87f2b5f5d75825207d61a272b168d8cab6.zip | |
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 8212c1aef125..d37d45c90ae6 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1369,9 +1369,9 @@ static int console_trylock_for_printk(unsigned int cpu) } } logbuf_cpu = UINT_MAX; + raw_spin_unlock(&logbuf_lock); if (wake) up(&console_sem); - raw_spin_unlock(&logbuf_lock); return retval; } |