From: "Bu, Yitian" <y...@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 <y...@qti.qualcomm.com>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: sta...@vger.kernel.org
Cc: stable...@vger.kernel.org
Link:
http://lkml.kernel.org/r/e807e903fe6cbe4d95e420fbfcc273b8274...@nasanexd01h.na.qualcomm.com
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Steven Rostedt <rost...@goodmis.org>
---
kernel/printk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/printk.c b/kernel/printk.c
index 972cc56..37b9b99 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -867,9 +867,9 @@ 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
