From aa34e62c2f0d4a105606971a1eb666f22338993b Mon Sep 17 00:00:00 2001 From: "Bu, Yitian" Date: Mon, 18 Feb 2013 12:53:37 +0000 Subject: [PATCH] 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 Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com Signed-off-by: Thomas Gleixner [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings Cc: Qiang Huang Cc: Li Zefan Cc: Jianguo Wu Signed-off-by: Greg Kroah-Hartman --- kernel/printk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/printk.c b/kernel/printk.c index e131c464f3329..e39adc13f5f57 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -822,9 +822,9 @@ 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 [] = -- 2.47.3