From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Tue, 13 Dec 2016 00:45:35 +0000 (-0800)
Subject: hung_task: decrement sysctl_hung_task_warnings only if it is positive
X-Git-Tag: v4.14-rc1~1942^2~23
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4ca5ede07c9871c13ae422c96d6d08dbd0df5eda;p=platform%2Fkernel%2Flinux-rpi3.git

hung_task: decrement sysctl_hung_task_warnings only if it is positive

Since sysctl_hung_task_warnings == -1 is allowed (infinite warnings),
commit 48a6d64edadb ("hung_task: allow hung_task_panic when
hung_task_warnings is 0") should decrement it only when it is not -1.

This prevents the kernel from ceasing warnings after the first
4294967295 ;)

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: John Siddle <jsiddle@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 2b59c82..40c07e4 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -106,7 +106,8 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
 	 * complain:
 	 */
 	if (sysctl_hung_task_warnings) {
-		sysctl_hung_task_warnings--;
+		if (sysctl_hung_task_warnings > 0)
+			sysctl_hung_task_warnings--;
 		pr_err("INFO: task %s:%d blocked for more than %ld seconds.\n",
 			t->comm, t->pid, timeout);
 		pr_err("      %s %s %.*s\n",