Messages in this thread Patch in this message | | | Date | Mon, 18 Feb 2013 22:53:42 -0500 | From | Steven Rostedt <> | Subject | [PATCH RT 3/7] printk: Fix rq->lock vs logbuf_lock unlock lock inversion |
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From: "Bu, Yitian" <ybu@qti.qualcomm.com>
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> Cc: stable@vger.kernel.org Cc: stable-rt@vger.kernel.org Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- kernel/printk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/printk.c b/kernel/printk.c index 7109711..56d7497 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -868,9 +868,9 @@ static int console_trylock_for_printk(unsigned int cpu, unsigned long flags) } } 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 [] = -- 1.7.10.4
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