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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 76A54C2BA2B for ; Thu, 9 Apr 2020 16:16:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C39320771 for ; Thu, 9 Apr 2020 16:16:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586448961; bh=6LS46W2TzoLE1O4k8wnCyqNIbJcGM/Dx+HEnC+5kpAs=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=ZXL+ILEATPjbSOTwmaPM+tB9EAaDlwzQD/MOcRSzrhQrvRxuqY0uLzgV+I1dexkAp mEx9NskjLtIU1qOKeozq66Kk5HGKEpMcIuG06d9vtA2t1ZY4BrXBqROya4zZpUiwat /TeMO5LBo+KDgkfnUI4GSXMVvj5jdL8lxN1ESDkw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728414AbgDIQP7 (ORCPT ); Thu, 9 Apr 2020 12:15:59 -0400 Received: from mail-lf1-f67.google.com ([209.85.167.67]:41111 "EHLO mail-lf1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726574AbgDIQP7 (ORCPT ); Thu, 9 Apr 2020 12:15:59 -0400 Received: by mail-lf1-f67.google.com with SMTP id z23so59836lfh.8 for ; Thu, 09 Apr 2020 09:15:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RbDQfT4mgxhb/9iMDJEsy+2/VqmlYknMsSAco0t5hrY=; b=dS3fIwTXf8LEsRZ6uN/uEIscofMTWcfi0maH/SslITya1R3AO2hUXiUHiDBwawvRg5 YP0GaiPojkCP1gqt+xZ/eATYoxB0p8j+zS7m97MnphuQF3+VtOM/8/B7V7FycK9iyd05 VSmcGDyJGyo9mJ7JYP+4IzLj1DsToi46/S49I= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RbDQfT4mgxhb/9iMDJEsy+2/VqmlYknMsSAco0t5hrY=; b=jaHuqYwc3lHSNHxOO+VEiqdx6WuM1hgNuwKIkuTh1P+kv2LykDAUJWObSYkSDr4/Gc mB5JtMngxng/pEeP1KZoW5JNyqQ5nxkfsw5qanl+QSD4zFn2ISeD7r6xcZ+X/c2xgcI/ QQtH5AZlpZVLFWSp9eglnpSsa5bNd6jDGGRkzmzljDUQPKIwrwT1jrkq1VOgTYxgsRAJ fw9luACjuh+3836vZCtUkFs+2RcaMVjgN37zCP++YVIqZ9q1HnM+zhmMSrk55scxAViW +pvI9vTIQoAKGomANOM1Lh6jW10RlOFsqDNselVzD4gaFtUedOlQ8LhDnZCRSIRVl+bL hUIg== X-Gm-Message-State: AGi0PuZHHQkOlRMJAfuS8rkCtcSQWa2G7BPH28w1QnNF5yK4e8q6WlPQ 1Xvpli6bcJSw8s+fE1E1qJubSPYHFTU= X-Google-Smtp-Source: APiQypLl52k8XfZ6vpxmrbHgfV5wcyb+r0LzIwdjbXFQ2oFfXJRcTlzJ3klZsce7e30ikHJDaW+Fdw== X-Received: by 2002:ac2:43b1:: with SMTP id t17mr31152lfl.9.1586448955824; Thu, 09 Apr 2020 09:15:55 -0700 (PDT) Received: from mail-lj1-f174.google.com (mail-lj1-f174.google.com. [209.85.208.174]) by smtp.gmail.com with ESMTPSA id u7sm10039884lfu.3.2020.04.09.09.15.54 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 09 Apr 2020 09:15:54 -0700 (PDT) Received: by mail-lj1-f174.google.com with SMTP id n17so240912lji.8 for ; Thu, 09 Apr 2020 09:15:54 -0700 (PDT) X-Received: by 2002:a2e:8652:: with SMTP id i18mr319121ljj.265.1586448953804; Thu, 09 Apr 2020 09:15:53 -0700 (PDT) MIME-Version: 1.0 References: <87blobnq02.fsf@x220.int.ebiederm.org> <87lfnda3w3.fsf@x220.int.ebiederm.org> <87blo45keg.fsf@x220.int.ebiederm.org> <87v9maxb5q.fsf@x220.int.ebiederm.org> <87y2r4so3i.fsf@x220.int.ebiederm.org> In-Reply-To: <87y2r4so3i.fsf@x220.int.ebiederm.org> From: Linus Torvalds Date: Thu, 9 Apr 2020 09:15:37 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [GIT PULL] Please pull proc and exec work for 5.7-rc1 To: "Eric W. Biederman" Cc: Waiman Long , Ingo Molnar , Will Deacon , Bernd Edlinger , Linux Kernel Mailing List , Alexey Gladkov Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 9, 2020 at 8:01 AM Eric W. Biederman wrote: > > When a thread going about it's ordinary business receives the SIGKILL > from de_thread the thread changes course and finds it's way to do_exit. > In do_exit the thread calls ptrace_event(PTRACE_EVENT_EXIT, ...) and > blocks waiting for the tracer to let it continue. Hah. That code isn't _supposed_ to block. may_ptrace_stop() is supposed to stop the blocking exactly so that it doesn't deadlock. I wonder why that doesn't work.. [ Goes and look ] Oh. I see. That ptrace_may_stop() only ever considered core-dumping, not execve(). But if _that_ is the reason for the deadlock, then it's trivially fixed. Famous last words.. Linus