tree f2e5c0a39e0916f76310e4f923f00055498fdb62
parent bbe3de2560280c0420d36a192e69f2772e893cf4
author Michal Hocko <mhocko@suse.com> 1459546294 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1459548217 -0500

oom, oom_reaper: do not enqueue task if it is on the oom_reaper_list head

Commit bb29902a7515 ("oom, oom_reaper: protect oom_reaper_list using
simpler way") has simplified the check for tasks already enqueued for
the oom reaper by checking tsk->oom_reaper_list != NULL.  This check is
not sufficient because the tsk might be the head of the queue without
any other tasks queued and then we would simply lockup looping on the
same task.  Fix the condition by checking for the head as well.

Fixes: bb29902a7515 ("oom, oom_reaper: protect oom_reaper_list using simpler way")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>