From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70BBEC43441 for ; Mon, 12 Nov 2018 18:30:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E5262245E for ; Mon, 12 Nov 2018 18:30:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E5262245E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730270AbeKMEY5 (ORCPT ); Mon, 12 Nov 2018 23:24:57 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:54555 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727354AbeKMEY5 (ORCPT ); Mon, 12 Nov 2018 23:24:57 -0500 Received: from in02.mta.xmission.com ([166.70.13.52]) by out01.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1gMGym-0002Sy-1F; Mon, 12 Nov 2018 11:30:32 -0700 Received: from 67-3-154-154.omah.qwest.net ([67.3.154.154] helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1gMGyl-0005jW-2g; Mon, 12 Nov 2018 11:30:31 -0700 From: ebiederm@xmission.com (Eric W. Biederman) To: Tycho Andersen Cc: Kees Cook , Oleg Nesterov , linux-kernel@vger.kernel.org References: <20181112171144.GI3645@cisco> Date: Mon, 12 Nov 2018 12:30:25 -0600 In-Reply-To: <20181112171144.GI3645@cisco> (Tycho Andersen's message of "Mon, 12 Nov 2018 10:11:44 -0700") Message-ID: <87efbqi1xa.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1gMGyl-0005jW-2g;;;mid=<87efbqi1xa.fsf@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=67.3.154.154;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18H2nkmPl5PiWGFUOdV+DY4jJJn4dYivog= X-SA-Exim-Connect-IP: 67.3.154.154 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: siginfo pid not populated from ptrace? X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tycho Andersen writes: > Hi Oleg, > > I've been running some tests on my seccomp series, and in one of the > tests on v4.20-rc2, I noticed, > > [ RUN ] global.syscall_restart > seccomp_bpf.c:2784:global.syscall_restart:Expected getpid() (1492) == info._sifields._kill.si_pid (0) > global.syscall_restart: Test failed at step #22 > > which seems unrelated to my series (the kernel was stock v4.20 with my > patches on top). > > I've been running a lot of tests, and only seen this once, so it seems > like a fairly rare race. I tried to look through the code but didn't > see anything obvious. Thoughts? My guess would be pid namespaces, or stopping for a signal other than SIGSTOP. If you can get this to reproduce at all it would be interesting to see si_signo and si_code. So that we can see just which signal is in info, and how it should be decoded. I see this test at line 2736 in 4.20-rc1 so there are almost 50 lines of change in your version of seccomp_bpf.c. So I hope I am reading the proper test. Eric