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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 6332FC3A5A9 for ; Mon, 4 May 2020 18:14:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43A9B20661 for ; Mon, 4 May 2020 18:14:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="i4ryt0VL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730641AbgEDSOi (ORCPT ); Mon, 4 May 2020 14:14:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1732353AbgEDSOa (ORCPT ); Mon, 4 May 2020 14:14:30 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24D73C061A0F for ; Mon, 4 May 2020 11:14:30 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id a4so214923pgc.0 for ; Mon, 04 May 2020 11:14:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=LJmSp82Ligwp7WEnd3OlCUWXViCVJLdpeeRX1nJdOAo=; b=i4ryt0VLTZEgW9WQe4ALh7GSYN1W1JwqThJe+wRYZgNPFUczOTCCP213kc/oLApap1 G0ekyN5KGn7TaWDNsjrmi06xnz+e4iALaF/Fp3Q1fClqTC4UOWucvy4YhBo+9Ij0krMM Z5LGe36D3Cdo4BukCzFGBjqJ8NjSHMXqYgJW4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=LJmSp82Ligwp7WEnd3OlCUWXViCVJLdpeeRX1nJdOAo=; b=M8xygXuCLmBexHOshWRoLhRnosBHU/WBMw/gB1IA0agXBn46Ze09S/apaxLLgRgncJ Z+cDG3DS7wVfHoqeGQefZNqu0Kx96sr+p6MvuA0oEdvfbAZTmpuAGzalVuREp0PEy1VQ sDk22d21ubzgNEm7W6/UZui8bh/wBSlztK058vc3b+OlecekliwLy5nlw721ThFFoKEP ZmXOrqLc1hxO/OvFpPQcbpAtqkGKp0x5h6UpeWMgUqBxPBa3RGYYG66b7mYDO0UEfQn1 qYSrw5Scm6HaREdIXMsMhXMuMt9cuhP0ngVEw7VKSXE8Yql9wa3Wv9Dn4J/xjfMIEKO2 SGCw== X-Gm-Message-State: AGi0PubwqBuQ5oq2Dr5G78scg12+aNWwJ79yrpNuDxvq6RgVsPtUaR5G 0GHV+L3hL1iurJHF08rPOmERJg== X-Google-Smtp-Source: APiQypJpzCwRNKHAwOjPu5Y0o7IOylpPdGPyjby32XHu799JivYz0nUFllc5ajHtfLH+GbCdEk043g== X-Received: by 2002:a65:5287:: with SMTP id y7mr232927pgp.86.1588616069763; Mon, 04 May 2020 11:14:29 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id 127sm9632296pfw.72.2020.05.04.11.14.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 May 2020 11:14:29 -0700 (PDT) Date: Mon, 4 May 2020 11:14:28 -0700 From: Kees Cook To: Pavel Tatashin Cc: jmorris@namei.org, sashal@kernel.org, linux-kernel@vger.kernel.org, pmladek@suse.com, sergey.senozhatsky@gmail.com, rostedt@goodmis.org, anton@enomsg.org, ccross@android.com, tony.luck@intel.com, robh+dt@kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v1 0/3] allow ramoops to collect all kmesg_dump events Message-ID: <202005041112.F3C8117F67@keescook> References: <20200502143555.543636-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200502143555.543636-1-pasha.tatashin@soleen.com> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Sat, May 02, 2020 at 10:35:52AM -0400, Pavel Tatashin wrote: > Currently, ramoops is capable to collect dmesg buffer only during > panic and oops events. However, it is desirable for shutdown performance > analysis reasons to optionally allow collecting dmesg buffers during other > events as well: reboot, kexec, emergency reboot etc. > > How to quickly test: > > virtme-run --mods=auto --kdir --mods=auto --kdir . \ > -a memmap=1G$8G -a ramoops.mem_address=0x200000000 \ > -a ramoops.mem_size=0x100000 -a ramoops.record_size=32768 \ > -a ramoops.dump_all=1 -a quiet --qemu-opts -m 8G > .. > # reboot -f > > After VM is back: > > # mount -t pstore pstore /mnt > # head /mnt/dmesg-ramoops-0 > Restart#1 Part1 Is there a reason that using ramoops.console_size isn't sufficient for this? I'm not strictly opposed to making these changes, but traditionally the granularity of dmesg output has been pretty easily "all or crashes" instead of a range within. -- Kees Cook