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 3AB96C41513 for ; Mon, 24 Jul 2023 06:24:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230255AbjGXGYu (ORCPT ); Mon, 24 Jul 2023 02:24:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229850AbjGXGYs (ORCPT ); Mon, 24 Jul 2023 02:24:48 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBAE3AF for ; Sun, 23 Jul 2023 23:24:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1690179840; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=GZEd3y5m5T6ObBTdJq73wFLu8a8S74TGSO2fnmaNWAY=; b=DoB6rkoI7r8Rl6n9nCpkLwy8qboLGWG9j7+QwV008VmO7B9NQETM48pc2DymJ3YyE0re7K 1sRvcxEVMoWFlKh2Ht18YJETq5SMVwfMwlrPGTnnsMWVKK3k1PRqER3vF8up1V3XHYWej8 liQUe7Cad5/JHgyyq0rtb0W3uD2F1dY= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-125-_BZ3PqXfNfSS-qgdQ3FSfQ-1; Mon, 24 Jul 2023 02:23:58 -0400 X-MC-Unique: _BZ3PqXfNfSS-qgdQ3FSfQ-1 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-31701b27d19so2062107f8f.1 for ; Sun, 23 Jul 2023 23:23:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690179837; x=1690784637; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=GZEd3y5m5T6ObBTdJq73wFLu8a8S74TGSO2fnmaNWAY=; b=Z6FLQ3qYRttGIGfsJTy5GXkWEQ60r92luPThxvqtfMhfo+71nlp1BMnBGX0h4KVfNc aQ4p3Xh3+09GpFN4WEuNPqUSjYNhziWGVPT/nMe/yzGzkMfzTWh3K3uioRvNwqTh4kZj pBl6qxlN32Z1V8gpytGzRZJ3ZF1vGV76aU/Cl73NLv1YBQ44uuVtKDfW53qZVx35ykhy wN39x2DZvKwAWP1CC+IjcjVBrEIdHw6ElPFrXhcG+sua3sQMDBlECZYIuYYK020Tw0Aj E5rj7KSJii74ArvL36KuGJMDZ1JTriF9poL6QuTS0ZDl+sNcNH5kA9wyFfk3DpDdqjAi /Trw== X-Gm-Message-State: ABy/qLYrzfqoPhe6IGeiwa/e41EFtBeBIcYrRwpABZfJvZmfVv3uCMVb CL7MDlKsM6Xivv9DNfN4IppwJc5uR7+VOn64ucLr750KAN0nOegeKYIPOJMTF3dThB4aiE0VYwZ YEY6b7x5MSWv1QgNIg1F8wfoK X-Received: by 2002:adf:e74f:0:b0:317:3e26:1699 with SMTP id c15-20020adfe74f000000b003173e261699mr4271856wrn.24.1690179837371; Sun, 23 Jul 2023 23:23:57 -0700 (PDT) X-Google-Smtp-Source: APBJJlGpW5m2s9rcQCA2y/SQn5BT+f9W2+cbW1Dhq/5Htb1O461c05ftyJmBOOOEljHVXnntLoe8dw== X-Received: by 2002:adf:e74f:0:b0:317:3e26:1699 with SMTP id c15-20020adfe74f000000b003173e261699mr4271844wrn.24.1690179836981; Sun, 23 Jul 2023 23:23:56 -0700 (PDT) Received: from ?IPV6:2003:d8:2f45:d000:62f2:4df0:704a:e859? (p200300d82f45d00062f24df0704ae859.dip0.t-ipconnect.de. [2003:d8:2f45:d000:62f2:4df0:704a:e859]) by smtp.gmail.com with ESMTPSA id w16-20020adfec50000000b003143867d2ebsm11776170wrn.63.2023.07.23.23.23.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 23 Jul 2023 23:23:56 -0700 (PDT) Message-ID: <86fd0ccb-f460-651f-8048-1026d905a2d6@redhat.com> Date: Mon, 24 Jul 2023 08:23:55 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v8 1/4] fs/proc/kcore: avoid bounce buffer for ktext data Content-Language: en-US To: Baoquan He , Jiri Olsa Cc: 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 References: From: David Hildenbrand Organization: Red Hat In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? @Lorenzo do you plan on reproduce + fix, or should we consider reverting that change? -- Cheers, David / dhildenb