From 1e11ad8dc42975d5c2bab7d478f6cd875602eda4 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Fri, 8 Jun 2012 13:21:26 -0700 Subject: [PATCH] mm, oom: fix badness score underflow If the privileges given to root threads (3% of allowable memory) or a negative value of /proc/pid/oom_score_adj happen to exceed the amount of rss of a thread, its badness score overflows as a result of commit a7f638f999ff ("mm, oom: normalize oom scores to oom_score_adj scale only for userspace"). Fix this by making the type signed and return 1, meaning the thread is still eligible for kill, if the value is negative. Reported-by: Dave Jones Acked-by: Oleg Nesterov Signed-off-by: David Rientjes Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index ed0e19677360..416637f0e924 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -183,7 +183,7 @@ static bool oom_unkillable_task(struct task_struct *p, unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, unsigned long totalpages) { - unsigned long points; + long points; if (oom_unkillable_task(p, memcg, nodemask)) return 0; @@ -223,7 +223,7 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, * Never return 0 for an eligible task regardless of the root bonus and * oom_score_adj (oom_score_adj can't be OOM_SCORE_ADJ_MIN here). */ - return points ? points : 1; + return points > 0 ? points : 1; } /* -- 2.20.1