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 D3599C001DE for ; Mon, 24 Jul 2023 08:18:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229577AbjGXIS4 (ORCPT ); Mon, 24 Jul 2023 04:18:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbjGXISz (ORCPT ); Mon, 24 Jul 2023 04:18:55 -0400 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB61D93; Mon, 24 Jul 2023 01:18:53 -0700 (PDT) Received: by mail-ej1-x634.google.com with SMTP id a640c23a62f3a-9926623e367so723726366b.0; Mon, 24 Jul 2023 01:18:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690186732; x=1690791532; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=7buxcMDQbXYavYttmKzovI7MVKRmkAiMGJ3Ho5r5lNY=; b=K+gsHI9j9r5lM9XR5WMABpbPvZlKmXj9i8awMb9HkIEa50nkUIRf2zcqCu/VonB6pr PsFFF9JmFN6t32dktfPlGOi4b0/k6/hsfQr73Zgn4fW1Dkt5My77WJsXR9Ipc/JeVokw ko5Awlouhbsuwp1TtlL+dGDxGLvZC3M3aN7VKH8K4hHO0QMwYE84iv8mOwJ43pIaHnzE j4z+wYwstI9IMtOWD9M8vuQuEFyhjSLqm8uS6gurwmoxQ1dY6JSi5/bLG6Y4zKFZQwhU 24zHhYW3fGOSqIZU4AVeJgPt4gI32ED6/cBUcsMB5rYdLAgJ6EHi22z5tkgwdAW/1rrK zYlQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690186732; x=1690791532; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=7buxcMDQbXYavYttmKzovI7MVKRmkAiMGJ3Ho5r5lNY=; b=YfJ7zXSvFlMTl2XOpXBO7fHTCzEAQrFbj1lH7TUFuZ+z+gP9Dsl05kwmGANKQoq89d N7vuJWC8nvEw95UKNF98F+2veuMuZiGnIW3V/j+nJiizbU9HfA+9KMPf5/DnkyXgsSLs US+x8QGpWg0n2leBHaqLt7gyDEgoJ+VpD7bbbO//jwC56ru33VEG9gWhzMbj0ADkZu5s BGeFPY+6CnwyYmhhGwrBo2lkIDoVkrousYTeY4RnD0X62i2xej/RwYz/FG1k4hDgrx53 MUcsxRrO/5uWvESNDleLxk7Q04YtjBTomEusR2hxEPqLnEIYDLmf1jcvAgI8kyWB6f9L qfKg== X-Gm-Message-State: ABy/qLa4sy1qSdhVqrllKeHBe5u2VFA58ZP/AIFI2UURGyLucAZtrCc1 ZfSDXOqM1WtlUaImS06S694Hxk6Zyac= X-Google-Smtp-Source: APBJJlGho1sN/bOHW+RH6k1NPxhZen/9JhFicpH04PsIewBGNWPrEjS7LDmgv8rz/WQW9yb2ay9KJw== X-Received: by 2002:a17:907:7758:b0:988:a578:4d65 with SMTP id kx24-20020a170907775800b00988a5784d65mr9049507ejc.32.1690186732037; Mon, 24 Jul 2023 01:18:52 -0700 (PDT) Received: from krava (2001-1ae9-1c2-4c00-726e-c10f-8833-ff22.ip6.tmcz.cz. [2001:1ae9:1c2:4c00:726e:c10f:8833:ff22]) by smtp.gmail.com with ESMTPSA id kg8-20020a17090776e800b0099329b3ab67sm6337302ejc.71.2023.07.24.01.18.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jul 2023 01:18:51 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Mon, 24 Jul 2023 10:18:48 +0200 To: Baoquan He Cc: David Hildenbrand , Jiri Olsa , Lorenzo Stoakes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Uladzislau Rezki , Matthew Wilcox , Liu Shixin , Jens Axboe , Alexander Viro Subject: Re: [PATCH v8 1/4] fs/proc/kcore: avoid bounce buffer for ktext data Message-ID: References: <86fd0ccb-f460-651f-8048-1026d905a2d6@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Jul 24, 2023 at 04:08:41PM +0800, Baoquan He wrote: > On 07/24/23 at 08:23am, David Hildenbrand wrote: > > Hi, > > > > > > > > I met this too when I executed below command to trigger a kcore reading. > > > I wanted to do a simple testing during system running and got this. > > > > > > makedumpfile --mem-usage /proc/kcore > > > > > > Later I tried your above objdump testing, it corrupted system too. > > > > > > > What do you mean with "corrupted system too" -- did it not only fail to > > dump the system, but also actually harmed the system? > > From my testing, reading kcore will cause system panic, then reboot. Not > sure if Jiri saw the same phenomenon. it did not crash for me, just the read error could you get console output from that? jirka > > > > > @Lorenzo do you plan on reproduce + fix, or should we consider reverting > > that change? > > When tested on a arm64 system, the reproducution is stable. I will have > a look too to see if I have some finding this week. >