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=-6.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E407AC4320E for ; Sat, 21 Aug 2021 16:51:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C512160231 for ; Sat, 21 Aug 2021 16:51:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232432AbhHUQv4 (ORCPT ); Sat, 21 Aug 2021 12:51:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229799AbhHUQvz (ORCPT ); Sat, 21 Aug 2021 12:51:55 -0400 Received: from mail-io1-xd31.google.com (mail-io1-xd31.google.com [IPv6:2607:f8b0:4864:20::d31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2FF98C061575 for ; Sat, 21 Aug 2021 09:51:16 -0700 (PDT) Received: by mail-io1-xd31.google.com with SMTP id y18so668206ioc.1 for ; Sat, 21 Aug 2021 09:51:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=EEkaJRkk7fbk+mpizy2Vd2alX2yC8T1hkBH60Wl8mj4=; b=qtIIpE8SBufQLuQamnrSS8zuw+V6BaKXuLbwznif/nkW3WYUpN6PQKVvRLSmh4s0hs qOGUBcO1i0eF56zN80pkrvfBfzP4CkmMX6y455hc0xeoL0Yu8v6qZ1B3OSyPlbZTCP7T 70q8spNeDQ6sICI9Kku+z0VmJZhBNrvh7cuADuqqGqccuBQxDqic+yuSYwSecm6v/uNj Er/PjAKAelp30OfRd0SwqWiSxYCBoOp+l7NqAt6JRX3KDvB31+8uSB1V1HEf6rFVC/Yc E/5kj9qMM93n4Y5aWcG8P0juniweRu+ftv10itW9au38En+QYjTRFpmASDfAZJ2GQSrw nGCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=EEkaJRkk7fbk+mpizy2Vd2alX2yC8T1hkBH60Wl8mj4=; b=l82L46hd6H1qTVQRcfZWJmQSNq8KbK2C1luRh//ITP3s3+qRNR671OWObV6x5sHgXk EzzfUctu54O0ZcjC18IAUhXpg7UWBap4dd9zl+JQFuStaCK4urNi3IiBpoAt2MVvPjre tZzPIOKsGnkrX2KzThA3UgFLJvFAnoszcEE9LBKvnfZg0Ex61GIyVE3Ye10JMmGZYFvU tNBIxD5fBoyPRNd1Of3ufooz2Be5qxDWVg5g7trtcO2afhwIR+2VxxEZARtwAOmUZ0UR Fx3mUtpVJ52DMVrIDTTvpr0PkymgEPM5mf1fVZvF4iADe9wgJMIGjOXmruQSDTxlgdJf 2Prg== X-Gm-Message-State: AOAM530Lzv08JbV3mij4ZbXNavwjKLoU3Nvmwu7MKMBLZ2F1+s4f2A18 LJ96kkdkfMUziVLNyCs5skxc5Q== X-Google-Smtp-Source: ABdhPJzRbjW8cYmHY3WuWUeLxspyHeaVk3QR1ggwwbUYZBJeia1nl/6xm7/dBlV8Y8O7RyrOYd7jwA== X-Received: by 2002:a02:2a07:: with SMTP id w7mr22897119jaw.96.1629564675481; Sat, 21 Aug 2021 09:51:15 -0700 (PDT) Received: from [192.168.1.116] ([66.219.217.159]) by smtp.gmail.com with ESMTPSA id p13sm5305098ils.69.2021.08.21.09.51.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 21 Aug 2021 09:51:15 -0700 (PDT) Subject: Re: [PATCH] coredump: Limit what can interrupt coredumps To: Olivier Langlois , Tony Battersby , "Eric W. Biederman" , Oleg Nesterov Cc: Linus Torvalds , Linux Kernel Mailing List , linux-fsdevel , io-uring , Alexander Viro , "Pavel Begunkov>" References: <87y2bh4jg5.fsf@disp2133> <87sg1p4h0g.fsf_-_@disp2133> <20210614141032.GA13677@redhat.com> <87pmwmn5m0.fsf@disp2133> <4d93d0600e4a9590a48d320c5a7dd4c54d66f095.camel@trillion01.com> <8af373ec-9609-35a4-f185-f9bdc63d39b7@cybernetics.com> <9d194813-ecb1-2fe4-70aa-75faf4e144ad@kernel.dk> <0bc38b13-5a7e-8620-6dce-18731f15467e@kernel.dk> <24c795c6-4ec4-518e-bf9b-860207eee8c7@kernel.dk> <05c0cadc-029e-78af-795d-e09cf3e80087@cybernetics.com> <84640f18-79ee-d8e4-5204-41a2c2330ed8@kernel.dk> <70526737949ab3ad2d8fc551531d286e0f3d88f4.camel@trillion01.com> <9dfb14c1a9ab686df0eeea553b39246bc5b51ede.camel@trillion01.com> From: Jens Axboe Message-ID: Date: Sat, 21 Aug 2021 10:51:13 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <9dfb14c1a9ab686df0eeea553b39246bc5b51ede.camel@trillion01.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/21/21 10:47 AM, Olivier Langlois wrote: > On Sat, 2021-08-21 at 06:08 -0400, Olivier Langlois wrote: >> On Tue, 2021-08-17 at 20:57 -0600, Jens Axboe wrote: >>> >>> Olivier, I sent a 5.10 version for Nathan, any chance you can test >>> this >>> one for the current kernels? Basically this one should work for >>> 5.11+, >>> and the later 5.10 version is just for 5.10. I'm going to send it >>> out >>> separately for review. >>> >>> I do think this is the right solution, barring a tweak maybe on >>> testing >>> notify == TWA_SIGNAL first before digging into the task struct. But >>> the >>> principle is sound, and it'll work for other users of TWA_SIGNAL as >>> well. None right now as far as I can tell, but the live patching is >>> switching to TIF_NOTIFY_SIGNAL as well which will also cause issues >>> with >>> coredumps potentially. >>> >> Ok, I am going to give it a shot. This solution is probably superior >> to >> the previous attempt as it does not inject io_uring dependency into >> the >> coredump module. >> >> The small extra change that I alluded to in my previous reply will >> still be relevant even if we go with your patch... >> >> I'll come back soon with your patch testing result and my small extra >> change that I keep teasing about. >> >> Greetings, >> > Jens, > > your patch doesn't compile with 5.12+. AFAIK, the reason is that > JOBCTL_TASK_WORK is gone. > > Wouldn't just a call to tracehook_notify_signal from do_coredump be > enough and backward compatible with every possible stable branches? That version is just for 5.10, the first I posted is applicable to 5.11+ -- Jens Axboe