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=-3.8 required=3.0 tests=BAYES_00, 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 4F13EC4338F for ; Sat, 21 Aug 2021 10:08:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DBEA61163 for ; Sat, 21 Aug 2021 10:08:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229609AbhHUKJe (ORCPT ); Sat, 21 Aug 2021 06:09:34 -0400 Received: from cloud48395.mywhc.ca ([173.209.37.211]:55480 "EHLO cloud48395.mywhc.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229968AbhHUKJe (ORCPT ); Sat, 21 Aug 2021 06:09:34 -0400 Received: from modemcable064.203-130-66.mc.videotron.ca ([66.130.203.64]:43170 helo=[192.168.1.179]) by cloud48395.mywhc.ca with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mHNvp-0001aX-2d; Sat, 21 Aug 2021 06:08:53 -0400 Message-ID: <70526737949ab3ad2d8fc551531d286e0f3d88f4.camel@trillion01.com> Subject: Re: [PATCH] coredump: Limit what can interrupt coredumps From: Olivier Langlois To: Jens Axboe , Tony Battersby , "Eric W. Biederman" , Oleg Nesterov Cc: Linus Torvalds , Linux Kernel Mailing List , linux-fsdevel , io-uring , Alexander Viro , "Pavel Begunkov>" Date: Sat, 21 Aug 2021 06:08:51 -0400 In-Reply-To: References: <87eeda7nqe.fsf@disp2133> <87pmwt6biw.fsf@disp2133> <87czst5yxh.fsf_-_@disp2133> <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> Organization: Trillion01 Inc Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.40.4 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - cloud48395.mywhc.ca X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - trillion01.com X-Get-Message-Sender-Via: cloud48395.mywhc.ca: authenticated_id: olivier@trillion01.com X-Authenticated-Sender: cloud48395.mywhc.ca: olivier@trillion01.com X-Source: X-Source-Args: X-Source-Dir: Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org 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,