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authorBu, Yitian <ybu@qti.qualcomm.com>2013-02-18 12:53:37 +0000
committerBen Hutchings <ben@decadent.org.uk>2013-07-27 05:34:04 +0100
commitff766b8d26c7669cc1ae9048a04cf0dd5607f02c (patch)
tree1bcf9a7510d1b3c38233ae5302fc162036082b43 /kernel
parent5f97f7c725181dfa6d58449b82276e362f3b9b15 (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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/printk.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/printk.c b/kernel/printk.c
index c0d12ea31c86..16688ecc918e 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -813,9 +813,9 @@ 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 [] =