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authorBu, Yitian <ybu@qti.qualcomm.com>2013-02-18 12:53:37 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-25 14:07:31 -0700
commit5df5df87f2b5f5d75825207d61a272b168d8cab6 (patch)
tree9909ae74a18000317fd1e4889fd9e67b36376442
parentbcaef288b2a3187de17220e86e15b762b3b0808e (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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/printk.c2
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;
}