From: Chen Jie Date: Fri, 11 Dec 2015 21:41:00 +0000 (-0800) Subject: mm/oom_kill.c: avoid attempting to kill init sharing same memory X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=a2b829d95958da2025ef844c0f53ac15ad720fac;p=openwrt%2Fstaging%2Fblogic.git mm/oom_kill.c: avoid attempting to kill init sharing same memory It's possible that an oom killed victim shares an ->mm with the init process and thus oom_kill_process() would end up trying to kill init as well. This has been shown in practice: Out of memory: Kill process 9134 (init) score 3 or sacrifice child Killed process 9134 (init) total-vm:1868kB, anon-rss:84kB, file-rss:572kB Kill process 1 (init) sharing same memory ... Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 And this will result in a kernel panic. If a process is forked by init and selected for oom kill while still sharing init_mm, then it's likely this system is in a recoverable state. However, it's better not to try to kill init and allow the machine to panic due to unkillable processes. [rientjes@google.com: rewrote changelog] [akpm@linux-foundation.org: fix inverted test, per Ben] Signed-off-by: Chen Jie Signed-off-by: David Rientjes Acked-by: Michal Hocko Acked-by: Hillf Danton Cc: Ben Hutchings Cc: Li Zefan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/oom_kill.c b/mm/oom_kill.c index d13a33918fa2..c12680993ff3 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -608,6 +608,8 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, continue; if (unlikely(p->flags & PF_KTHREAD)) continue; + if (is_global_init(p)) + continue; if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) continue;