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>

1 files changed, 2 insertions, 1 deletions

diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 2b59c82cc3e1..40c07e4fa116 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",