35 lines
1.1 KiB
Diff
35 lines
1.1 KiB
Diff
Subject: printk: Fix rq->lock vs logbuf_lock unlock lock inversion
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From: "Bu, Yitian" <ybu@qti.qualcomm.com>
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Date: Mon, 18 Feb 2013 12:53:37 +0000
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commit 07354eb1a74d1 ("locking printk: Annotate logbuf_lock as raw")
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reintroduced a lock inversion problem which was fixed in commit
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0b5e1c5255 ("printk: Release console_sem after logbuf_lock"). This
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happened probably when fixing up patch rejects.
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Restore the ordering and unlock logbuf_lock before releasing
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console_sem.
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Signed-off-by: ybu <ybu@qti.qualcomm.com>
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Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
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Cc: stable@vger.kernel.org
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Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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---
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kernel/printk.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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--- a/kernel/printk.c
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+++ b/kernel/printk.c
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@@ -1358,9 +1358,9 @@ static int console_trylock_for_printk(un
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}
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}
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logbuf_cpu = UINT_MAX;
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+ raw_spin_unlock(&logbuf_lock);
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if (wake)
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up(&console_sem);
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- raw_spin_unlock(&logbuf_lock);
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return retval;
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}
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