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=-5.8 required=3.0 tests=BAYES_00,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 B1668C4361B for ; Fri, 18 Dec 2020 18:51:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69F2823B84 for ; Fri, 18 Dec 2020 18:51:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726701AbgLRSvI (ORCPT ); Fri, 18 Dec 2020 13:51:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726652AbgLRSvH (ORCPT ); Fri, 18 Dec 2020 13:51:07 -0500 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99F2FC0617B0 for ; Fri, 18 Dec 2020 10:50:27 -0800 (PST) Received: by mail-pl1-x635.google.com with SMTP id r4so1849785pls.11 for ; Fri, 18 Dec 2020 10:50:27 -0800 (PST) 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=aV2MC/7DJ97wJPGYRClkcJ8CaAh6ktn5YU+LrCJaZoE=; b=lbwxU9LwTsIKYUS4hy5LPDGKFymptBbuBe53KnM83Wq/YslIQoQ7ZIZkF2Pw2fiQD2 08XcJke5mrOJAuUHgid5o9SuORXnfgXxHtBA9Uqg6acIrQ1FW95r3Gn6tY6/XGDx83be 4zmVCuY3xN5HdgdKsn5pZ1Kv6t1PPcrvy79Zw= 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=aV2MC/7DJ97wJPGYRClkcJ8CaAh6ktn5YU+LrCJaZoE=; b=b93tNgqbNAECT4Xv1N6b5ACKKEvrTCBQ8R8MfwnRAZbckdApVCCUhZ7u/5n5LMb1zs tKF9+IlGx2mdRcYjw/+cS5LSYs2duvMBmuWnPiL29JKcA0XxliBn2W3D3QHXJniIcQ/r KXb7I/SvEv/8nKGSJj4jDj50NeT7h65aqSSvstW/g1IGGEjClRbDSvxv+0PIZmaA2LNz Mm6QVH1GbtZsavRLJh7iBZAuKh0TvF/xvC/90QdIgFS27DAGGHacOipGUfPx/MaTZMFy ZpZ3wFzmFcZKWGFzDw/r1ecJHBcGzI7PtEJ57j+gQmQ/r3CNkNpmJimqcjfamKLCBdXw t6Yg== X-Gm-Message-State: AOAM530u8kdFrw1K67sVGeKunp5OTTRzus6j63VI6ASKW0VrYOKemOuR NRbwAuRXLrpQIBjJvM0yqkLXFQ== X-Google-Smtp-Source: ABdhPJz5MIaRdOmBLXaCQYiPuegrM0xZhG5U2A9JsyDhMfwlY/KrnNLKCIAHuHpJD9GptLhFz78/iQ== X-Received: by 2002:a17:90a:a394:: with SMTP id x20mr5429746pjp.24.1608317427139; Fri, 18 Dec 2020 10:50:27 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id z23sm9189336pfn.202.2020.12.18.10.50.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Dec 2020 10:50:26 -0800 (PST) Date: Fri, 18 Dec 2020 10:50:25 -0800 From: Kees Cook To: Ulf Hansson Cc: Bhaskara Budiredla , Colin Cross , Tony Luck , Sunil Kovvuri Goutham , "linux-mmc@vger.kernel.org" , Linux Kernel Mailing List , Christoph Hellwig Subject: Re: [EXT] Re: [PATCH 1/2] mmc: Support kmsg dumper based on pstore/blk Message-ID: <202012181047.99F11364@keescook> References: <20201207115753.21728-1-bbudiredla@marvell.com> <20201207115753.21728-2-bbudiredla@marvell.com> <202012151232.843EB2CB49@keescook> 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-mmc@vger.kernel.org On Wed, Dec 16, 2020 at 11:44:26AM +0100, Ulf Hansson wrote: > In any case, I didn't catch *why* pstore needs to force block device > drivers to implement specific pstore hooks to support the pstore file > system. I don't think this is the way it should work, for many For panic, pstore must avoid any path that might sleep. In a perfect world, it should also use as little code as possible, to avoid potentially tripping over areas of the kernel that might be broken. -- Kees Cook