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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CA96C433EF for ; Fri, 8 Jul 2022 23:22:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238853AbiGHXWl (ORCPT ); Fri, 8 Jul 2022 19:22:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232885AbiGHXWi (ORCPT ); Fri, 8 Jul 2022 19:22:38 -0400 Received: from mail-io1-xd36.google.com (mail-io1-xd36.google.com [IPv6:2607:f8b0:4864:20::d36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8B6A419B8 for ; Fri, 8 Jul 2022 16:22:37 -0700 (PDT) Received: by mail-io1-xd36.google.com with SMTP id u20so326459iob.8 for ; Fri, 08 Jul 2022 16:22:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=juliacomputing.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=A1ej6xhQ4FQa3gB+bjJzvRwbSKtsNZgXVjMOdxWop0U=; b=T5+dnDjMlpvDZ95jVJ0Gbkjx7yW9RrbWDQen7vlZbSwo8htD2oWpwMrAqo19j/oWY2 Ql09fEK9qIzBQ4etmbl54LV21ZcDN27D5wpd0TEC8g2ifL8WFPaRJ6fwziZgccp7I6d9 Bs4SzxOiQB+xb6Jhun8odbaT6ehL1c+18X4QqvO8BId4J95rFyeal72lISX8lilgtZjb hvWe/ksm9W0uNty1uDhm2v8Zm6pkxJZxoWWnw7qAnZ5Q4iQYJpQ6Jb3SWmpkz+6ckPw0 1KyOgb5Rxb/Zyky6LqxvzNQbM8XbQDto4jJ/cn2HDxtcl8WUtqH0oC5aBXRS6hvJgAd7 LNzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=A1ej6xhQ4FQa3gB+bjJzvRwbSKtsNZgXVjMOdxWop0U=; b=AioaTsgsrMs8W4tzLUv/64KhPnXZCkB/BqTehLXlXvjV8Hs+jYnnU5l1e2+PHxI8La 0kE5K1MQIB2/iQ4f7EBTp14tZ4kH3kyhZBu8+snT3JpXYlXQFVcJ1kg+eY+1PhSnE+Xx o9Mt+CeKTNwZHImQbndDqcmD7QFTp80HeJyK7igdTLrounwHSiu8Gzsow5f60OcOllcA W1pTiFqbSNOw49tgArfqPvY0S3/ezdUJF6UB0wIC/g53wrQuFoafOWc7xfdhfHuizyRn XDTUdLCSB255XmC6Q6wlKYawiGJln8adymFvMcHEx8+HGOtMiiFsTGfMw0Alj5o/Om/9 Usyw== X-Gm-Message-State: AJIora83p/7f+Ct2fZzuSfqTHsTFevFfchByhRErqbSnpfk7Qx0yQVuf /R7CboLpKzzRinhsXhLVwGlQ0yNTcOCIarO1f/+7YA== X-Google-Smtp-Source: AGRyM1uav8UBMS/JUkZBWQNip2eXO7srgkoO7bZ5Y7THjyyE5hC8rSU3z9GPO/e5ccxXmCqAOghIX+aIDHdAJRvrdw8= X-Received: by 2002:a05:6638:250c:b0:33b:adde:3077 with SMTP id v12-20020a056638250c00b0033badde3077mr3756924jat.148.1657322557119; Fri, 08 Jul 2022 16:22:37 -0700 (PDT) MIME-Version: 1.0 References: <20220421150248.667412396@infradead.org> <20220421150654.817117821@infradead.org> <87czhap9dy.fsf@email.froward.int.ebiederm.org> <878rrrh32q.fsf_-_@email.froward.int.ebiederm.org> <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> <87k0b0apne.fsf_-_@email.froward.int.ebiederm.org> <87a6bv6dl6.fsf_-_@email.froward.int.ebiederm.org> <87r13gd4xy.fsf_-_@email.froward.int.ebiederm.org> <87edyvgs2s.fsf@email.froward.int.ebiederm.org> In-Reply-To: <87edyvgs2s.fsf@email.froward.int.ebiederm.org> From: Keno Fischer Date: Fri, 8 Jul 2022 19:22:01 -0400 Message-ID: Subject: Re: [PATCH 0/3] ptrace: Stop supporting SIGKILL for PTRACE_EVENT_EXIT To: "Eric W. Biederman" Cc: Linux Kernel Mailing List , mingo@kernel.org, Sebastian Andrzej Siewior , Peter Zijlstra , Jann Horn , Kees Cook , Alexander Gordeev , "Robert O'Callahan" , Kyle Huey , Oleg Nesterov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Eric, On Fri, Jul 8, 2022 at 6:25 PM Eric W. Biederman wrote: > > Recently I had a conversation where it was pointed out to me that > > SIGKILL sent to a tracee stropped in PTRACE_EVENT_EXIT is quite > > difficult for a tracer to handle. > > > > RR folks any comments? > > Did I properly understand what Keno Fischer was asking for when we > talked in person? Yes, this is indeed what I had in mind. I have not yet had the opportunity to try out your patch series (sorry), but from visual inspection, it does indeed do what I wanted, which is to make sure that a tracee stays in PTRACE_EVENT_EXIT for the tracer to inspect, even if there is another SIGKILL incoming simultaneously (since otherwise it may be impossible for the tracer to observe the PTRACE_EVENT_EXIT if two SIGKILLs come in rapid succession). I will try to take this series for a proper spin shortly. Keno