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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 1618AC54E8A for ; Sun, 10 May 2020 20:32:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED71820737 for ; Sun, 10 May 2020 20:32:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Fw8KyfeR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729342AbgEJUb6 (ORCPT ); Sun, 10 May 2020 16:31:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1729327AbgEJUb5 (ORCPT ); Sun, 10 May 2020 16:31:57 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A202FC061A0E for ; Sun, 10 May 2020 13:31:57 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id j21so3553809pgb.7 for ; Sun, 10 May 2020 13:31:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=IGhCzVMcFSG8RfD2dnuoWGbvQKbAh3BbNL764FWITOg=; b=Fw8KyfeRY2o+iHX91RUx34YBABbxf6VuNlYyNsnrWdXif3s/ACuQVflYL+CJptaAuw gTkwG01vIwsxYH9f/tLpXxU2UnH3b3f+//pWjovG+r86XkEYeKe1/MFAGtf/PMTdBtIm McUum85+3EHfgMNTrU3qDsZ2l6EjV1jWiANN8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=IGhCzVMcFSG8RfD2dnuoWGbvQKbAh3BbNL764FWITOg=; b=qaY8XOjAFs3JjfLc8PaRSvQaLtdomZ/4qKdAmUVMN/X3ScgcViOK0xIpQmxYbllGja ym1eG3GaeV19TUdv6hy6L7tvY695OzG4yr3+xfyO6/4MrcBCwOdThWsx5gj1T9/gr77d 3sjcM5lWYrOHoSDafs0HpdH05Y1V8eQmDskYXemmbDvqnnVNFApC7sozu5X+RE+rKYxG WorDXIMTcCWdJwWZdAZF7vJ0v+6/764Wbx3MFbEn5wf1Gq9rNz0M3Je8ZSCaIHmKhbSy 7T33/YPvjPzCnyML8+hsvuzn8hGWUv63Gtiz687ZUcvLbhASp9UMWIfeETLIu/WCgdGS Z71g== X-Gm-Message-State: AGi0PuYss0If8IR982yF6OtICT1ZkZYrWWfbdue1i4m+ChvreQZLk5li g+pFRr/qBvavp8NATuWI/WS9VA== X-Google-Smtp-Source: APiQypJsRU9h+Mob7IV8V9hVnNZaLYlsu6I2Ml5FQNRy6o1udqUOVm9mMtwEsQaiHAaxP5NUL+g+Lg== X-Received: by 2002:a63:dd51:: with SMTP id g17mr10543432pgj.2.1589142717130; Sun, 10 May 2020 13:31:57 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f30sm8149570pje.29.2020.05.10.13.31.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 10 May 2020 13:31:56 -0700 (PDT) From: Kees Cook To: WeiXiong Liao Cc: Kees Cook , Anton Vorontsov , Colin Cross , Tony Luck , Jonathan Corbet , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Rob Herring , Pavel Tatashin , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org Subject: [PATCH v7 18/18] pstore/blk: Introduce "best_effort" mode Date: Sun, 10 May 2020 13:24:36 -0700 Message-Id: <20200510202436.63222-19-keescook@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200510202436.63222-1-keescook@chromium.org> References: <20200510202436.63222-1-keescook@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org In order to use arbitrary block devices as a pstore backend, provide a new module param named "best_effort", which will allow using any block device, even if it has not provided a panic_write callback. Signed-off-by: Kees Cook --- fs/pstore/blk.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index 0dea8ded2de2..ad46860d5a78 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -51,6 +51,10 @@ static long ftrace_size = -1; module_param(ftrace_size, long, 0400); MODULE_PARM_DESC(ftrace_size, "ftrace size in kbytes"); +static bool best_effort; +module_param(best_effort, bool, 0400); +MODULE_PARM_DESC(best_effort, "use best effort to write (i.e. do not require storage driver pstore support, default: off)"); + /* * blkdev - the block device to use for pstore storage * @@ -376,7 +380,8 @@ static int __register_pstore_blk(struct pstore_blk_info *info) } /* only allow driver matching the @blkdev */ - if (!binfo.devt || MAJOR(binfo.devt) != info->major) { + if (!binfo.devt || (!best_effort && + MAJOR(binfo.devt) != info->major)) { pr_debug("invalid major %u (expect %u)\n", info->major, MAJOR(binfo.devt)); ret = -ENODEV; @@ -479,6 +484,20 @@ int pstore_blk_get_config(struct pstore_blk_config *info) } EXPORT_SYMBOL_GPL(pstore_blk_get_config); +static int __init pstore_blk_init(void) +{ + struct pstore_blk_info info = { }; + int ret = 0; + + mutex_lock(&pstore_blk_lock); + if (!pstore_zone_info && best_effort && blkdev[0]) + ret = __register_pstore_blk(&info); + mutex_unlock(&pstore_blk_lock); + + return ret; +} +late_initcall(pstore_blk_init); + static void __exit pstore_blk_exit(void) { mutex_lock(&pstore_blk_lock); -- 2.20.1