From 959217c84c2765434cd2cbf3d7ffdc09e90834f9 Mon Sep 17 00:00:00 2001
From: Li Pengcheng <lipengcheng8@huawei.com>
Date: Sat, 5 Nov 2016 10:15:59 +0800
Subject: [PATCH] pstore: Actually give up during locking failure

Without a return after the pr_err(), dumps will collide when two threads
call pstore_dump() at the same time.

Signed-off-by: Liu Hailong <liuhailong5@huawei.com>
Signed-off-by: Li Pengcheng <lipengcheng8@huawei.com>
Signed-off-by: Li Zhong <lizhong11@hisilicon.com>
[kees: improved commit message]
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 fs/pstore/platform.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 14984d902a99..60e6db6f5da2 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -493,6 +493,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
 		if (!is_locked) {
 			pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
 				       , in_nmi() ? "NMI" : why);
+			return;
 		}
 	} else {
 		spin_lock_irqsave(&psinfo->buf_lock, flags);