From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman) Subject: Re: [PATCH v2] inotify: Convert to using per-namespace limits Date: Fri, 09 Dec 2016 18:38:57 +1300 Message-ID: <87zik5lkzy.fsf@xmission.com> References: <20161010164046.GG24081@quack2.suse.cz> <1476171382-11911-1-git-send-email-kernel@kyup.com> <674564a4-ff05-b4d6-4a98-8cfc2e609325@kyup.com> <87twafci52.fsf@xmission.com> <100ecab5-6656-9ed6-c0f4-b9c97eae506a@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <100ecab5-6656-9ed6-c0f4-b9c97eae506a-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> (Nikolay Borisov's message of "Thu, 8 Dec 2016 10:14:50 +0200") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Nikolay Borisov Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, jack-AlSwsSmVLrQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org List-Id: containers.vger.kernel.org Nikolay Borisov writes: > On 8.12.2016 08:58, Nikolay Borisov wrote: >> >> >> On 8.12.2016 03:40, Eric W. Biederman wrote: >>> Nikolay Borisov writes: >>> >>>> Gentle ping, now that rc1 has shipped and Jan's sysctl concern hopefully >>>> resolved. >>> >>> After getting slowed down by some fixes I am now taking a hard look at >>> your patch in the hopes of merging it. >>> >>> Did you happen to see the kbuild test roboot boot failures and did you >>> happen to look into what caused them? I have just skimmed them and it >>> appears to be related to your patch. >> >> I saw them in the beginning but they did look like a generic memory >> corruption and I believe at the time those patches were submitted there >> was a lingering memory corruption hitting various patches. Thus I didn't >> think it was related to my patches. I've since left my work so been >> taking a bit of time off and haven't looked really hard, so those >> patches have been kind of lingering. >> >> >> But now that you mention it I will try and take a second look to see >> what might cause the memory corruption? Is there a way to force 0day to >> re-run them to see whether the failure was indeed caused by my patches >> or were intermittent? > > Ok, I took another look into the report but bear in mind that the > corruption indeed happened in retire_userns_sysctls. But also this row > in the report leads me to believe it's not my patch that's the culprit: > > [ 65.527277] INFO: Allocated in setup_userns_sysctls+0x3f/0xa6 age=5 > cpu=1 pid=418 > [ 65.558397] INFO: Freed in free_ctx+0x1d/0x20 age=6 cpu=0 pid=19 > > > So a free_ctx function did free it originally, likely causing the > corruption. And there is no such function involved in the code I'm touching. Yes. I read through your patch carefully and it doesn't look like it could possibly cause that kind of corruption, the code is just too simple. So I have (belatedly) placed this change in linux-next. Eric