From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f198.google.com (mail-qk0-f198.google.com [209.85.220.198]) by kanga.kvack.org (Postfix) with ESMTP id 79F656B0261 for ; Tue, 12 Jul 2016 12:51:55 -0400 (EDT) Received: by mail-qk0-f198.google.com with SMTP id r65so44970158qkd.1 for ; Tue, 12 Jul 2016 09:51:55 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id o28si2682405qtb.120.2016.07.12.09.51.54 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 12 Jul 2016 09:51:54 -0700 (PDT) Date: Tue, 12 Jul 2016 18:52:16 +0200 From: Oleg Nesterov Subject: Re: bug in memcg oom-killer results in a hung syscall in another process in the same cgroup Message-ID: <20160712165215.GB4557@redhat.com> References: <20160711064150.GB5284@dhcp22.suse.cz> <20160712071927.GD14586@dhcp22.suse.cz> <57851224.2020902@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <57851224.2020902@yandex-team.ru> Sender: owner-linux-mm@kvack.org List-ID: To: Konstantin Khlebnikov Cc: Shayan Pooya , Michal Hocko , koct9i@gmail.com, cgroups mailinglist , LKML , linux-mm@kvack.org On 07/12, Konstantin Khlebnikov wrote: > > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -2808,8 +2808,9 @@ asmlinkage __visible void schedule_tail(struct task_struct *prev) > balance_callback(rq); > preempt_enable(); > > - if (current->set_child_tid) > - put_user(task_pid_vnr(current), current->set_child_tid); > + if (current->set_child_tid && > + put_user(task_pid_vnr(current), current->set_child_tid)) > + force_sig(SIGSEGV, current); > } > > Add Oleg into CC. IIRR he had some ideas how to fix this. =) Heh. OK, OK, thank you Konstantin ;) I'll try to recall tomorrow, but iirc I only have some ideas of how we can happily blame the FAULT_FLAG_USER logic. d, in this particular case, perhaps glibc/set_child_tid too because (again, iirc) it would nice to simply kill it, it is only used for some sanity checks... Oleg. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org