From patchwork Fri Oct 29 18:44:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 12593365 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D92FC4167E for ; Fri, 29 Oct 2021 18:45:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3794360ED5 for ; Fri, 29 Oct 2021 18:45:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230319AbhJ2Srk (ORCPT ); Fri, 29 Oct 2021 14:47:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230024AbhJ2Sri (ORCPT ); Fri, 29 Oct 2021 14:47:38 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60A2AC061767; Fri, 29 Oct 2021 11:45:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=e0kQ9lexrz/qqzeBlCnlPoAJWghIWhtZZ671P32g3p8=; b=FpxDCxk8IO1mG4zWS0ldz83Uxj w186goL4kq3ESpX9xXWX/6IcmJiiTFhXXY961Q0/4A2mQBaxbco8qA2jwr/dEnDGyugndRWDCa1Vh shC6HPR0Sr/uj4Bbi72kJ6KG553ptfw7oS/OImHV6GFio9R0kcK5ao8S3ehj38EQh60LreMkvkOwo maIJao7jLVTPNXWclpzZ0Zn6nLADNT3lYUwlPUQxnT0J/2d/T2CfGIP1rCt1KhqCHdReJkoPM/Cpd CjR8YqqrxHCadKRl67yK1c7KpOcDA5/5w3Ma10goXzf2pZXdQ5OPIMYlDL+cyvI2zVamVPhZOvf6v F+ohMoyA==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgWsA-00Bq0M-3I; Fri, 29 Oct 2021 18:45:02 +0000 From: Luis Chamberlain To: tj@kernel.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, jeyu@kernel.org, shuah@kernel.org Cc: bvanassche@acm.org, dan.j.williams@intel.com, joe@perches.com, tglx@linutronix.de, mcgrof@kernel.org, keescook@chromium.org, rostedt@goodmis.org, minchan@kernel.org, linux-spdx@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Goldwyn Rodrigues , Kuno Woudt , Richard Fontana , copyleft-next@lists.fedorahosted.org, Ciaran Farrell , Christopher De Nicolo , Christoph Hellwig , Jonathan Corbet , Thorsten Leemhuis Subject: [PATCH v9 1/6] LICENSES: Add the copyleft-next-0.3.1 license Date: Fri, 29 Oct 2021 11:44:55 -0700 Message-Id: <20211029184500.2821444-2-mcgrof@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211029184500.2821444-1-mcgrof@kernel.org> References: <20211029184500.2821444-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add the full text of the copyleft-next-0.3.1 license to the kernel tree as well as the required tags for reference and tooling. The license text was copied directly from the copyleft-next project's git tree [0]. Discussion of using copyleft-next-0.3.1 on Linux started since June, 2016 [1]. In the end Linus' preference was to have drivers use MODULE_LICENSE("GPL") to make it clear that the GPL applies when it comes to Linux [2]. Additionally, even though copyleft-next-0.3.1 has been found to be to be GPLv2 compatible by three attorneys at SUSE and Redhat [3], to err on the side of caution we simply recommend to always use the "OR" language for this license [4]. Even though it has been a goal of the project to be GPL-v2 compatible to be certain in 2016 I asked for a clarification about what makes copyleft-next GPLv2 compatible and also asked for a summary of benefits. This prompted some small minor changes to make compatibility even further clear and as of copyleft 0.3.1 compatibility should be crystal clear [5]. The summary of why copyleft-next 0.3.1 is compatible with GPLv2 is explained as follows: Like GPLv2, copyleft-next requires distribution of derivative works ("Derived Works" in copyleft-next 0.3.x) to be under the same license. Ordinarily this would make the two licenses incompatible. However, copyleft-next 0.3.1 says: "If the Derived Work includes material licensed under the GPL, You may instead license the Derived Work under the GPL." "GPL" is defined to include GPLv2. In practice this means copyleft-next code in Linux may be licensed under the GPL2, however there are additional obvious gains for bringing contributions from Linux outbound where copyleft-next is preferred. A summary of benefits why projects outside of Linux might prefer to use copyleft-next >= 0.3.1 over GPLv2: o It is much shorter and simpler o It has an explicit patent license grant, unlike GPLv2 o Its notice preservation conditions are clearer o More free software/open source licenses are compatible with it (via section 4) o The source code requirement triggered by binary distribution is much simpler in a procedural sense o Recipients potentially have a contract claim against distributors who are noncompliant with the source code requirement o There is a built-in inbound=outbound policy for upstream contributions (cf. Apache License 2.0 section 5) o There are disincentives to engage in the controversial practice of copyleft/ proprietary dual-licensing o In 15 years copyleft expires, which can be advantageous for legacy code o There are explicit disincentives to bringing patent infringement claims accusing the licensed work of infringement (see 10b) o There is a cure period for licensees who are not compliant with the license (there is no cure opportunity in GPLv2) o copyleft-next has a 'built-in or-later' provision The first driver submission to Linux under this dual strategy was lib/test_sysctl.c through commit 9308f2f9e7f05 ("test_sysctl: add dedicated proc sysctl test driver") merged in July 2017. Shortly after that I also added test_kmod through commit d9c6a72d6fa29 ("kmod: add test driver to stress test the module loader") in the same month. These two drivers went in just a few months before the SPDX license practice kicked in. In 2018 Kuno Woudt went through the process to get SPDX identifiers for copyleft-next [6] [7]. Although there are SPDX tags for copyleft-next-0.3.0, we only document use in Linux starting from copyleft-next-0.3.1 which makes GPLv2 compatibility crystal clear. This patch will let us update the two Linux selftest drivers in subsequent patches with their respective SPDX license identifiers and let us remove repetitive license boiler plate. [0] https://github.com/copyleft-next/copyleft-next/blob/master/Releases/copyleft-next-0.3.1 [1] https://lore.kernel.org/lkml/1465929311-13509-1-git-send-email-mcgrof@kernel.org/ [2] https://lore.kernel.org/lkml/CA+55aFyhxcvD+q7tp+-yrSFDKfR0mOHgyEAe=f_94aKLsOu0Og@mail.gmail.com/ [3] https://lore.kernel.org/lkml/20170516232702.GL17314@wotan.suse.de/ [4] https://lkml.kernel.org/r/1495234558.7848.122.camel@linux.intel.com [5] https://lists.fedorahosted.org/archives/list/copyleft-next@lists.fedorahosted.org/thread/JTGV56DDADWGKU7ZKTZA4DLXTGTLNJ57/#SQMDIKBRAVDOCT4UVNOOCRGBN2UJIKHZ [6] https://spdx.org/licenses/copyleft-next-0.3.0.html [7] https://spdx.org/licenses/copyleft-next-0.3.1.html Cc: Goldwyn Rodrigues Cc: Kuno Woudt Cc: Richard Fontana Cc: copyleft-next@lists.fedorahosted.org Cc: Ciaran Farrell Cc: Christopher De Nicolo Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: Thomas Gleixner Cc: Jonathan Corbet Cc: Thorsten Leemhuis Cc: Andrew Morton Reviewed-by: Kees Cook Signed-off-by: Luis Chamberlain --- LICENSES/dual/copyleft-next-0.3.1 | 237 ++++++++++++++++++++++++++++++ 1 file changed, 237 insertions(+) create mode 100644 LICENSES/dual/copyleft-next-0.3.1 diff --git a/LICENSES/dual/copyleft-next-0.3.1 b/LICENSES/dual/copyleft-next-0.3.1 new file mode 100644 index 000000000000..086bcb74b478 --- /dev/null +++ b/LICENSES/dual/copyleft-next-0.3.1 @@ -0,0 +1,237 @@ +Valid-License-Identifier: copyleft-next-0.3.1 +SPDX-URL: https://spdx.org/licenses/copyleft-next-0.3.1 +Usage-Guide: + This license can be used in code, it has been found to be GPLv2 compatible + by attorneys at Redhat and SUSE, however to air on the side of caution, + it's best to only use it together with a GPL2 compatible license using "OR". + To use the copyleft-next-0.3.1 license put the following SPDX tag/value + pair into a comment according to the placement guidelines in the + licensing rules documentation: + SPDX-License-Identifier: GPL-2.0 OR copyleft-next-0.3.1 + SPDX-License-Identifier: GPL-2.0-only OR copyleft-next 0.3.1 + SPDX-License-Identifier: GPL-2.0+ OR copyleft-next-0.3.1 + SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 +License-Text: + +======================================================================= + + copyleft-next 0.3.1 ("this License") + Release date: 2016-04-29 + +1. License Grants; No Trademark License + + Subject to the terms of this License, I grant You: + + a) A non-exclusive, worldwide, perpetual, royalty-free, irrevocable + copyright license, to reproduce, Distribute, prepare derivative works + of, publicly perform and publicly display My Work. + + b) A non-exclusive, worldwide, perpetual, royalty-free, irrevocable + patent license under Licensed Patents to make, have made, use, sell, + offer for sale, and import Covered Works. + + This License does not grant any rights in My name, trademarks, service + marks, or logos. + +2. Distribution: General Conditions + + You may Distribute Covered Works, provided that You (i) inform + recipients how they can obtain a copy of this License; (ii) satisfy the + applicable conditions of sections 3 through 6; and (iii) preserve all + Legal Notices contained in My Work (to the extent they remain + pertinent). "Legal Notices" means copyright notices, license notices, + license texts, and author attributions, but does not include logos, + other graphical images, trademarks or trademark legends. + +3. Conditions for Distributing Derived Works; Outbound GPL Compatibility + + If You Distribute a Derived Work, You must license the entire Derived + Work as a whole under this License, with prominent notice of such + licensing. This condition may not be avoided through such means as + separate Distribution of portions of the Derived Work. + + If the Derived Work includes material licensed under the GPL, You may + instead license the Derived Work under the GPL. + +4. Condition Against Further Restrictions; Inbound License Compatibility + + When Distributing a Covered Work, You may not impose further + restrictions on the exercise of rights in the Covered Work granted under + this License. This condition is not excused merely because such + restrictions result from Your compliance with conditions or obligations + extrinsic to this License (such as a court order or an agreement with a + third party). + + However, You may Distribute a Covered Work incorporating material + governed by a license that is both OSI-Approved and FSF-Free as of the + release date of this License, provided that compliance with such + other license would not conflict with any conditions stated in other + sections of this License. + +5. Conditions for Distributing Object Code + + You may Distribute an Object Code form of a Covered Work, provided that + you accompany the Object Code with a URL through which the Corresponding + Source is made available, at no charge, by some standard or customary + means of providing network access to source code. + + If you Distribute the Object Code in a physical product or tangible + storage medium ("Product"), the Corresponding Source must be available + through such URL for two years from the date of Your most recent + Distribution of the Object Code in the Product. However, if the Product + itself contains or is accompanied by the Corresponding Source (made + available in a customarily accessible manner), You need not also comply + with the first paragraph of this section. + + Each direct and indirect recipient of the Covered Work from You is an + intended third-party beneficiary of this License solely as to this + section 5, with the right to enforce its terms. + +6. Symmetrical Licensing Condition for Upstream Contributions + + If You Distribute a work to Me specifically for inclusion in or + modification of a Covered Work (a "Patch"), and no explicit licensing + terms apply to the Patch, You license the Patch under this License, to + the extent of Your copyright in the Patch. This condition does not + negate the other conditions of this License, if applicable to the Patch. + +7. Nullification of Copyleft/Proprietary Dual Licensing + + If I offer to license, for a fee, a Covered Work under terms other than + a license that is OSI-Approved or FSF-Free as of the release date of this + License or a numbered version of copyleft-next released by the + Copyleft-Next Project, then the license I grant You under section 1 is no + longer subject to the conditions in sections 3 through 5. + +8. Copyleft Sunset + + The conditions in sections 3 through 5 no longer apply once fifteen + years have elapsed from the date of My first Distribution of My Work + under this License. + +9. Pass-Through + + When You Distribute a Covered Work, the recipient automatically receives + a license to My Work from Me, subject to the terms of this License. + +10. Termination + + Your license grants under section 1 are automatically terminated if You + + a) fail to comply with the conditions of this License, unless You cure + such noncompliance within thirty days after becoming aware of it, or + + b) initiate a patent infringement litigation claim (excluding + declaratory judgment actions, counterclaims, and cross-claims) + alleging that any part of My Work directly or indirectly infringes + any patent. + + Termination of Your license grants extends to all copies of Covered + Works You subsequently obtain. Termination does not terminate the + rights of those who have received copies or rights from You subject to + this License. + + To the extent permission to make copies of a Covered Work is necessary + merely for running it, such permission is not terminable. + +11. Later License Versions + + The Copyleft-Next Project may release new versions of copyleft-next, + designated by a distinguishing version number ("Later Versions"). + Unless I explicitly remove the option of Distributing Covered Works + under Later Versions, You may Distribute Covered Works under any Later + Version. + +** 12. No Warranty ** +** ** +** My Work is provided "as-is", without warranty. You bear the risk ** +** of using it. To the extent permitted by applicable law, each ** +** Distributor of My Work excludes the implied warranties of title, ** +** merchantability, fitness for a particular purpose and ** +** non-infringement. ** + +** 13. Limitation of Liability ** +** ** +** To the extent permitted by applicable law, in no event will any ** +** Distributor of My Work be liable to You for any damages ** +** whatsoever, whether direct, indirect, special, incidental, or ** +** consequential damages, whether arising under contract, tort ** +** (including negligence), or otherwise, even where the Distributor ** +** knew or should have known about the possibility of such damages. ** + +14. Severability + + The invalidity or unenforceability of any provision of this License + does not affect the validity or enforceability of the remainder of + this License. Such provision is to be reformed to the minimum extent + necessary to make it valid and enforceable. + +15. Definitions + + "Copyleft-Next Project" means the project that maintains the source + code repository at + as of the release date of this License. + + "Corresponding Source" of a Covered Work in Object Code form means (i) + the Source Code form of the Covered Work; (ii) all scripts, + instructions and similar information that are reasonably necessary for + a skilled developer to generate such Object Code from the Source Code + provided under (i); and (iii) a list clearly identifying all Separate + Works (other than those provided in compliance with (ii)) that were + specifically used in building and (if applicable) installing the + Covered Work (for example, a specified proprietary compiler including + its version number). Corresponding Source must be machine-readable. + + "Covered Work" means My Work or a Derived Work. + + "Derived Work" means a work of authorship that copies from, modifies, + adapts, is based on, is a derivative work of, transforms, translates or + contains all or part of My Work, such that copyright permission is + required. The following are not Derived Works: (i) Mere Aggregation; + (ii) a mere reproduction of My Work; and (iii) if My Work fails to + explicitly state an expectation otherwise, a work that merely makes + reference to My Work. + + "Distribute" means to distribute, transfer or make a copy available to + someone else, such that copyright permission is required. + + "Distributor" means Me and anyone else who Distributes a Covered Work. + + "FSF-Free" means classified as 'free' by the Free Software Foundation. + + "GPL" means a version of the GNU General Public License or the GNU + Affero General Public License. + + "I"/"Me"/"My" refers to the individual or legal entity that places My + Work under this License. "You"/"Your" refers to the individual or legal + entity exercising rights in My Work under this License. A legal entity + includes each entity that controls, is controlled by, or is under + common control with such legal entity. "Control" means (a) the power to + direct the actions of such legal entity, whether by contract or + otherwise, or (b) ownership of more than fifty percent of the + outstanding shares or beneficial ownership of such legal entity. + + "Licensed Patents" means all patent claims licensable royalty-free by + Me, now or in the future, that are necessarily infringed by making, + using, or selling My Work, and excludes claims that would be infringed + only as a consequence of further modification of My Work. + + "Mere Aggregation" means an aggregation of a Covered Work with a + Separate Work. + + "My Work" means the particular work of authorship I license to You + under this License. + + "Object Code" means any form of a work that is not Source Code. + + "OSI-Approved" means approved as 'Open Source' by the Open Source + Initiative. + + "Separate Work" means a work that is separate from and independent of a + particular Covered Work and is not by its nature an extension or + enhancement of the Covered Work, and/or a runtime library, standard + library or similar component that is used to generate an Object Code + form of a Covered Work. + + "Source Code" means the preferred form of a work for making + modifications to it. From patchwork Fri Oct 29 18:44:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 12593373 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4EB39C4332F for ; Fri, 29 Oct 2021 18:45:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 392AC611BD for ; Fri, 29 Oct 2021 18:45:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231293AbhJ2Srx (ORCPT ); Fri, 29 Oct 2021 14:47:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230163AbhJ2Sri (ORCPT ); Fri, 29 Oct 2021 14:47:38 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1D66C061570; Fri, 29 Oct 2021 11:45:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=r84288GmeDVjDY3xNymFGbcisITDhLv6aqXTm20aeME=; b=LYqJ7TMrp0MnnPGfgthGg9vbez DXw1vHhNAWrrkUSwCZHMibvX7XZ/iK0yLFkMcC0G781lrWojDAbU49dyJN1tn+7q5cph5UEPKjisV 24HJwTwf31sjtiKdDIlB4jFuevHg6RcnNeh4iCnYK0BBEGPgXKH6S6HHscKerZiijAic8nralXx3e ro22kqhCUaLezXVMAc7Ll8TPHd1D7BdbHCrXg4HxUUPTLSZUIH3TunoEiraK/BQucC3/S8RBCyd2K 8ihq4M5xXvbJ11WDYfvR+h0vIMGEu+qSh3zuB8kv6KAQFluYRGHjmgzONCix8thYKEhWKBy8g9YFe 7uBU6PeA==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgWsA-00Bq0O-6h; Fri, 29 Oct 2021 18:45:02 +0000 From: Luis Chamberlain To: tj@kernel.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, jeyu@kernel.org, shuah@kernel.org Cc: bvanassche@acm.org, dan.j.williams@intel.com, joe@perches.com, tglx@linutronix.de, mcgrof@kernel.org, keescook@chromium.org, rostedt@goodmis.org, minchan@kernel.org, linux-spdx@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Goldwyn Rodrigues , Kuno Woudt , Richard Fontana , copyleft-next@lists.fedorahosted.org, Ciaran Farrell , Christopher De Nicolo , Christoph Hellwig , Jonathan Corbet , Thorsten Leemhuis Subject: [PATCH v9 2/6] testing: use the copyleft-next-0.3.1 SPDX tag Date: Fri, 29 Oct 2021 11:44:56 -0700 Message-Id: <20211029184500.2821444-3-mcgrof@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211029184500.2821444-1-mcgrof@kernel.org> References: <20211029184500.2821444-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Two selftests drivers exist under the copyleft-next license. These drivers were added prior to SPDX practice taking full swing in the kernel. Now that we have an SPDX tag for copylef-next-0.3.1 documented, embrace it and remove the boiler plate. Cc: Goldwyn Rodrigues Cc: Kuno Woudt Cc: Richard Fontana Cc: copyleft-next@lists.fedorahosted.org Cc: Ciaran Farrell Cc: Christopher De Nicolo Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: Thomas Gleixner Cc: Jonathan Corbet Cc: Thorsten Leemhuis Cc: Andrew Morton Reviewed-by: Kees Cook Signed-off-by: Luis Chamberlain --- lib/test_kmod.c | 12 +----------- lib/test_sysctl.c | 12 +----------- tools/testing/selftests/kmod/kmod.sh | 13 +------------ tools/testing/selftests/sysctl/sysctl.sh | 12 +----------- 4 files changed, 4 insertions(+), 45 deletions(-) diff --git a/lib/test_kmod.c b/lib/test_kmod.c index ce1589391413..d62afd89dc63 100644 --- a/lib/test_kmod.c +++ b/lib/test_kmod.c @@ -1,18 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 /* * kmod stress test driver * * Copyright (C) 2017 Luis R. Rodriguez - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the Free - * Software Foundation; either version 2 of the License, or at your option any - * later version; or, when distributed separately from the Linux kernel or - * when incorporated into other software packages, subject to the following - * license: - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of copyleft-next (version 0.3.1 or later) as published - * at http://copyleft-next.org/. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c index 3750323973f4..9e5bd10a930a 100644 --- a/lib/test_sysctl.c +++ b/lib/test_sysctl.c @@ -1,18 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 /* * proc sysctl test driver * * Copyright (C) 2017 Luis R. Rodriguez - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the Free - * Software Foundation; either version 2 of the License, or at your option any - * later version; or, when distributed separately from the Linux kernel or - * when incorporated into other software packages, subject to the following - * license: - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of copyleft-next (version 0.3.1 or later) as published - * at http://copyleft-next.org/. */ /* diff --git a/tools/testing/selftests/kmod/kmod.sh b/tools/testing/selftests/kmod/kmod.sh index afd42387e8b2..7189715d7960 100755 --- a/tools/testing/selftests/kmod/kmod.sh +++ b/tools/testing/selftests/kmod/kmod.sh @@ -1,18 +1,7 @@ #!/bin/bash -# +# SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 # Copyright (C) 2017 Luis R. Rodriguez # -# This program is free software; you can redistribute it and/or modify it -# under the terms of the GNU General Public License as published by the Free -# Software Foundation; either version 2 of the License, or at your option any -# later version; or, when distributed separately from the Linux kernel or -# when incorporated into other software packages, subject to the following -# license: -# -# This program is free software; you can redistribute it and/or modify it -# under the terms of copyleft-next (version 0.3.1 or later) as published -# at http://copyleft-next.org/. - # This is a stress test script for kmod, the kernel module loader. It uses # test_kmod which exposes a series of knobs for the API for us so we can # tweak each test in userspace rather than in kernelspace. diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh index 19515dcb7d04..2046c603a4d4 100755 --- a/tools/testing/selftests/sysctl/sysctl.sh +++ b/tools/testing/selftests/sysctl/sysctl.sh @@ -1,16 +1,6 @@ #!/bin/bash +# SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 # Copyright (C) 2017 Luis R. Rodriguez -# -# This program is free software; you can redistribute it and/or modify it -# under the terms of the GNU General Public License as published by the Free -# Software Foundation; either version 2 of the License, or at your option any -# later version; or, when distributed separately from the Linux kernel or -# when incorporated into other software packages, subject to the following -# license: -# -# This program is free software; you can redistribute it and/or modify it -# under the terms of copyleft-next (version 0.3.1 or later) as published -# at http://copyleft-next.org/. # This performs a series tests against the proc sysctl interface. From patchwork Fri Oct 29 18:44:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 12593369 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8755AC001B6 for ; Fri, 29 Oct 2021 18:45:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F80360ED5 for ; Fri, 29 Oct 2021 18:45:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230381AbhJ2Srl (ORCPT ); Fri, 29 Oct 2021 14:47:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230084AbhJ2Sri (ORCPT ); Fri, 29 Oct 2021 14:47:38 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A138FC061714; Fri, 29 Oct 2021 11:45:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=sL6KAaxM/wK26VE1Sm18okT9xaQN1vOROR274t15iAA=; b=HHEo25hNvMyxCU3iNUOdjTDAWr m9SOVKTvjO1BaKiEwIXd2XM3sPKc+qxQJAgKjiZnQGJYS2f2/8dLmIGbYTpacdWmiaNBleVtWXgxF US5Lau198dZLIEE+IKgtoU5hxjet0V2FeH+gKCZX6dYWv3pM5Q/qauZ4KKtElfC0ZQee76U3c1KDG +FHsKnDkix+DNFo65BgTNUnZ86OTDWiBOQvjGvVZPS4Idss2qxwwKkReMisClZVVTTvNPa61k+P9W YPVnkbndGtYR77ulsGu2EX/shq13CNKAzLZJx9PjsIiFOTIlRaKrvFQSt+bigaj6Daz2/StHoZc4X D0suek0Q==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgWsA-00Bq0T-9N; Fri, 29 Oct 2021 18:45:02 +0000 From: Luis Chamberlain To: tj@kernel.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, jeyu@kernel.org, shuah@kernel.org Cc: bvanassche@acm.org, dan.j.williams@intel.com, joe@perches.com, tglx@linutronix.de, mcgrof@kernel.org, keescook@chromium.org, rostedt@goodmis.org, minchan@kernel.org, linux-spdx@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 3/6] selftests: add tests_sysfs module Date: Fri, 29 Oct 2021 11:44:57 -0700 Message-Id: <20211029184500.2821444-4-mcgrof@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211029184500.2821444-1-mcgrof@kernel.org> References: <20211029184500.2821444-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This adds a new selftest module which can be used to test sysfs, which would otherwise require using an existing driver. This lets us muck with a template driver to test breaking things without affecting system behaviour or requiring the dependencies of a real device driver. A series of 28 tests are added. Support for using two device types are supported: * misc * block Contrary to sysctls, sysfs requires a full write to happen at once, and so we reduce the digit tests to single writes. Two main sysfs knobs are provided for testing reading/storing, one which doesn't incur any delays and another which can incur programmed delays. What locks are held, if any, are configurable, at module load time, or through dynamic configuration at run time. Since sysfs is a technically filesystem, but a pseudo one, which requires a kernel user, our test_sysfs module and respective test script embraces fstests format for tests in the kernel ring bufffer. Likewise, a scraper for kernel crashes is provided which matches what fstests does as well. Two tests are kept disabled as they are a demonstration of what not to do as it can cause a deadlock with sysfs. These tests provides a mechanism to easily show proof and demo how the deadlock can happen: Demos the deadlock with a device specific lock ./tools/testing/selftests/sysfs/sysfs.sh -t 0027 Demos the deadlock with rtnl_lock() ./tools/testing/selftests/sysfs/sysfs.sh -t 0028 Drivers should *avoid* sharing a lock on rmmod and on sysfs ops. This selftests will shortly be expanded upon with more tests which require further kernel changes in order to provide better test coverage. Signed-off-by: Luis Chamberlain --- MAINTAINERS | 7 + lib/Kconfig.debug | 12 + lib/Makefile | 1 + lib/test_sysfs.c | 894 ++++++++++++++++++ tools/testing/selftests/sysfs/Makefile | 12 + tools/testing/selftests/sysfs/config | 2 + tools/testing/selftests/sysfs/settings | 1 + tools/testing/selftests/sysfs/sysfs.sh | 1197 ++++++++++++++++++++++++ 8 files changed, 2126 insertions(+) create mode 100644 lib/test_sysfs.c create mode 100644 tools/testing/selftests/sysfs/Makefile create mode 100644 tools/testing/selftests/sysfs/config create mode 100644 tools/testing/selftests/sysfs/settings create mode 100755 tools/testing/selftests/sysfs/sysfs.sh diff --git a/MAINTAINERS b/MAINTAINERS index 5f87f622ac18..8b458c4dd577 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18393,6 +18393,13 @@ L: linux-mmc@vger.kernel.org S: Maintained F: drivers/mmc/host/sdhci-pci-dwc-mshc.c +SYSFS TEST DRIVER +M: Luis Chamberlain +L: linux-kernel@vger.kernel.org +S: Maintained +F: lib/test_sysfs.c +F: tools/testing/selftests/sysfs/ + SYSTEM CONFIGURATION (SYSCON) M: Lee Jones M: Arnd Bergmann diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 44a6df361016..ec531b423c0e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2344,6 +2344,18 @@ config TEST_SYSCTL If unsure, say N. +config TEST_SYSFS + tristate "sysfs test driver" + depends on SYSFS + depends on NET + depends on BLOCK + help + This builds the "test_sysfs" module. This driver enables to test the + sysfs file system safely without affecting production knobs which + might alter system functionality. + + If unsure, say N. + config BITFIELD_KUNIT tristate "KUnit test bitfield functions at runtime" depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index 364c23f15578..741c1be29781 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o obj-$(CONFIG_TEST_BITOPS) += test_bitops.o CFLAGS_test_bitops.o += -Werror obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o +obj-$(CONFIG_TEST_SYSFS) += test_sysfs.o obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o obj-$(CONFIG_TEST_IDA) += test_ida.o obj-$(CONFIG_KASAN_KUNIT_TEST) += test_kasan.o diff --git a/lib/test_sysfs.c b/lib/test_sysfs.c new file mode 100644 index 000000000000..2a6ec072da60 --- /dev/null +++ b/lib/test_sysfs.c @@ -0,0 +1,894 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 +/* + * Copyright (C) 2021 Luis Chamberlain + * + * sysfs test driver + * + * This module allows us to add race conditions which we can test for + * against the sysfs filesystem. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static bool enable_lock; +module_param(enable_lock, bool_enable_only, 0644); +MODULE_PARM_DESC(enable_lock, + "enable locking on reads / stores from the start"); + +static bool enable_lock_on_rmmod; +module_param(enable_lock_on_rmmod, bool_enable_only, 0644); +MODULE_PARM_DESC(enable_lock_on_rmmod, + "enable locking on rmmod"); + +static bool use_rtnl_lock; +module_param(use_rtnl_lock, bool_enable_only, 0644); +MODULE_PARM_DESC(use_rtnl_lock, + "use an rtnl_lock instead of the device mutex_lock"); + +static unsigned int write_delay_msec_y = 500; +module_param_named(write_delay_msec_y, write_delay_msec_y, uint, 0644); +MODULE_PARM_DESC(write_delay_msec_y, "msec write delay for writes to y"); + +static unsigned int test_devtype; +module_param_named(devtype, test_devtype, uint, 0644); +MODULE_PARM_DESC(devtype, "device type to register"); + +static bool enable_busy_alloc; +module_param(enable_busy_alloc, bool_enable_only, 0644); +MODULE_PARM_DESC(enable_busy_alloc, "do a fake allocation during writes"); + +static bool enable_debugfs; +module_param(enable_debugfs, bool_enable_only, 0644); +MODULE_PARM_DESC(enable_debugfs, "enable a few debugfs files"); + +static bool enable_verbose_writes; +module_param(enable_verbose_writes, bool_enable_only, 0644); +MODULE_PARM_DESC(enable_debugfs, "enable stores to print verbose information"); + +static unsigned int delay_rmmod_ms; +module_param_named(delay_rmmod_ms, delay_rmmod_ms, uint, 0644); +MODULE_PARM_DESC(delay_rmmod_ms, "if set how many ms to delay rmmod before device deletion"); + +static bool enable_verbose_rmmod; +module_param(enable_verbose_rmmod, bool_enable_only, 0644); +MODULE_PARM_DESC(enable_verbose_rmmod, "enable verbose print messages on rmmod"); + +static int sysfs_test_major; + +/** + * test_config - used for configuring how the sysfs test device will behave + * + * @enable_lock: if enabled a lock will be used when reading/storing variables + * @enable_lock_on_rmmod: if enabled a lock will be used when reading/storing + * sysfs attributes, but it will also be used to lock on rmmod. This is + * useful to test for a deadlock and should serve as an example of what + * drivers should *not* do. + * @use_rtnl_lock: if enabled instead of configuration specific mutex, we'll + * use the rtnl_lock. If your test case is modifying this on the fly + * while doing other stores / reads, things will break as a lock can be + * left contending. Best is that tests use this knob serially, without + * allowing userspace to modify other knobs while this one changes. + * @write_delay_msec_y: the amount of delay to use when writing to y + * @enable_busy_alloc: if enabled we'll do a large allocation between + * writes. We immediately free right away. We also schedule to give the + * kernel some time to re-use any memory we don't need. This is intened + * to mimic typical driver behaviour. + */ +struct test_config { + bool enable_lock; + bool enable_lock_on_rmmod; + bool use_rtnl_lock; + unsigned int write_delay_msec_y; + bool enable_busy_alloc; +}; + +/** + * enum sysfs_test_devtype - sysfs device type + * @TESTDEV_TYPE_MISC: misc device type + * @TESTDEV_TYPE_BLOCK: use a block device for the sysfs test device. + */ +enum sysfs_test_devtype { + TESTDEV_TYPE_MISC = 0, + TESTDEV_TYPE_BLOCK, +}; + +/** + * sysfs_test_device - test device to help test sysfs + * + * @devtype: the type of device to use + * @config: configuration for the test + * @config_mutex: protects configuration of test + * @misc_dev: we use a misc device under the hood + * @disk: represents a disk when used as a block device + * @dev: pointer to misc_dev's own struct device + * @dev_idx: unique ID for test device + * @x: variable we can use to test read / store + * @y: slow variable we can use to test read / store + */ +struct sysfs_test_device { + enum sysfs_test_devtype devtype; + struct test_config config; + struct mutex config_mutex; + struct miscdevice misc_dev; + struct gendisk *disk; + struct device *dev; + int dev_idx; + int x; + int y; +}; + +static struct sysfs_test_device *first_test_dev; + +static struct miscdevice *dev_to_misc_dev(struct device *dev) +{ + return dev_get_drvdata(dev); +} + +static struct sysfs_test_device *misc_dev_to_test_dev(struct miscdevice *misc_dev) +{ + return container_of(misc_dev, struct sysfs_test_device, misc_dev); +} + +static struct sysfs_test_device *devblock_to_test_dev(struct device *dev) +{ + return (struct sysfs_test_device *)dev_to_disk(dev)->private_data; +} + +static struct sysfs_test_device *devmisc_to_testdev(struct device *dev) +{ + struct miscdevice *misc_dev; + + misc_dev = dev_to_misc_dev(dev); + return misc_dev_to_test_dev(misc_dev); +} + +static struct sysfs_test_device *dev_to_test_dev(struct device *dev) +{ + if (test_devtype == TESTDEV_TYPE_MISC) + return devmisc_to_testdev(dev); + else if (test_devtype == TESTDEV_TYPE_BLOCK) + return devblock_to_test_dev(dev); + return NULL; +} + +static void test_dev_config_lock(struct sysfs_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + + if (config->enable_lock) { + if (config->use_rtnl_lock) + rtnl_lock(); + else + mutex_lock(&test_dev->config_mutex); + } +} + +static void test_dev_config_unlock(struct sysfs_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + + if (config->enable_lock) { + if (config->use_rtnl_lock) + rtnl_unlock(); + else + mutex_unlock(&test_dev->config_mutex); + } +} + +static void test_dev_config_lock_rmmod(struct sysfs_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + + if (config->enable_lock_on_rmmod) + test_dev_config_lock(test_dev); +} + +static void test_dev_config_unlock_rmmod(struct sysfs_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + + if (config->enable_lock_on_rmmod) + test_dev_config_unlock(test_dev); +} + +static void free_test_dev_sysfs(struct sysfs_test_device *test_dev) +{ + if (test_dev) { + kfree_const(test_dev->misc_dev.name); + test_dev->misc_dev.name = NULL; + kfree(test_dev); + test_dev = NULL; + } +} + +static void test_sysfs_reset_vals(struct sysfs_test_device *test_dev) +{ + test_dev->x = 3; + test_dev->y = 4; +} + +static ssize_t config_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int len = 0; + + test_dev_config_lock(test_dev); + + len += sysfs_emit_at(buf, len, "Configuration for: %s\n", + dev_name(dev)); + len += sysfs_emit_at(buf, len, "x:\t%d\n", test_dev->x); + len += sysfs_emit_at(buf, len, "y:\t%d\n", test_dev->y); + len += sysfs_emit_at(buf, len, "enable_lock:\t%s\n", + config->enable_lock ? "true" : "false"); + len += sysfs_emit_at(buf, len, "enable_lock_on_rmmmod:\t%s\n", + config->enable_lock_on_rmmod ? "true" : "false"); + len += sysfs_emit_at(buf, len, "use_rtnl_lock:\t%s\n", + config->use_rtnl_lock ? "true" : "false"); + len += sysfs_emit_at(buf, len, "write_delay_msec_y:\t%d\n", + config->write_delay_msec_y); + len += sysfs_emit_at(buf, len, "enable_busy_alloc:\t%s\n", + config->enable_busy_alloc ? "true" : "false"); + len += sysfs_emit_at(buf, len, "enable_debugfs:\t%s\n", + enable_debugfs ? "true" : "false"); + len += sysfs_emit_at(buf, len, "enable_verbose_writes:\t%s\n", + enable_verbose_writes ? "true" : "false"); + + test_dev_config_unlock(test_dev); + + return len; +} +static DEVICE_ATTR_RO(config); + +static ssize_t reset_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + /* + * We compromise and simplify this condition and do not use a lock + * here as the lock type can change. + */ + config->enable_lock = false; + config->enable_lock_on_rmmod = false; + config->use_rtnl_lock = false; + config->enable_busy_alloc = false; + test_sysfs_reset_vals(test_dev); + + dev_info(dev, "reset\n"); + + return count; +} +static DEVICE_ATTR_WO(reset); + +static void test_dev_busy_alloc(struct sysfs_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + char *ignore; + + if (!config->enable_busy_alloc) + return; + + ignore = kzalloc(sizeof(struct sysfs_test_device) * 10, GFP_KERNEL); + kfree(ignore); + + schedule(); +} + +static ssize_t test_dev_x_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + int ret; + + test_dev_busy_alloc(test_dev); + test_dev_config_lock(test_dev); + + ret = kstrtoint(buf, 10, &test_dev->x); + if (ret) + count = ret; + + if (enable_verbose_writes) + dev_info(test_dev->dev, "wrote x = %d\n", test_dev->x); + + test_dev_config_unlock(test_dev); + + return count; +} + +static ssize_t test_dev_x_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + int ret; + + test_dev_config_lock(test_dev); + ret = sysfs_emit(buf, "%d\n", test_dev->x); + test_dev_config_unlock(test_dev); + + return ret; +} +static DEVICE_ATTR_RW(test_dev_x); + +static ssize_t test_dev_y_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config; + int y; + int ret; + + test_dev_busy_alloc(test_dev); + test_dev_config_lock(test_dev); + + config = &test_dev->config; + + ret = kstrtoint(buf, 10, &y); + if (ret) + count = ret; + + msleep(config->write_delay_msec_y); + test_dev->y = test_dev->x + y + 7; + + if (enable_verbose_writes) + dev_info(test_dev->dev, "wrote y = %d\n", test_dev->y); + + test_dev_config_unlock(test_dev); + + return count; +} + +static ssize_t test_dev_y_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + int ret; + + test_dev_config_lock(test_dev); + ret = sysfs_emit(buf, "%d\n", test_dev->y); + test_dev_config_unlock(test_dev); + + return ret; +} +static DEVICE_ATTR_RW(test_dev_y); + +static ssize_t config_enable_lock_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int ret; + int val; + + ret = kstrtoint(buf, 10, &val); + if (ret) + return ret; + + /* + * We compromise for simplicty and do not lock when changing + * locking configuration, with the assumption userspace tests + * will know this. + */ + if (val) + config->enable_lock = true; + else + config->enable_lock = false; + + return count; +} + +static ssize_t config_enable_lock_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + ssize_t ret; + + test_dev_config_lock(test_dev); + ret = sysfs_emit(buf, "%d\n", config->enable_lock); + test_dev_config_unlock(test_dev); + + return ret; +} +static DEVICE_ATTR_RW(config_enable_lock); + +static ssize_t config_enable_lock_on_rmmod_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int ret; + int val; + + ret = kstrtoint(buf, 10, &val); + if (ret) + return ret; + + test_dev_config_lock(test_dev); + if (val) + config->enable_lock_on_rmmod = true; + else + config->enable_lock_on_rmmod = false; + test_dev_config_unlock(test_dev); + + return count; +} + +static ssize_t config_enable_lock_on_rmmod_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + ssize_t ret; + + test_dev_config_lock(test_dev); + ret = sysfs_emit(buf, "%d\n", config->enable_lock_on_rmmod); + test_dev_config_unlock(test_dev); + + return ret; +} +static DEVICE_ATTR_RW(config_enable_lock_on_rmmod); + +static ssize_t config_use_rtnl_lock_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int ret; + int val; + + ret = kstrtoint(buf, 10, &val); + if (ret) + return ret; + + /* + * We compromise and simplify this condition and do not use a lock + * here as the lock type can change. + */ + if (val) + config->use_rtnl_lock = true; + else + config->use_rtnl_lock = false; + + return count; +} + +static ssize_t config_use_rtnl_lock_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return sysfs_emit(buf, "%d\n", config->use_rtnl_lock); +} +static DEVICE_ATTR_RW(config_use_rtnl_lock); + +static ssize_t config_write_delay_msec_y_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int ret; + int val; + + ret = kstrtoint(buf, 10, &val); + if (ret) + return ret; + + test_dev_config_lock(test_dev); + config->write_delay_msec_y = val; + test_dev_config_unlock(test_dev); + + return count; +} + +static ssize_t config_write_delay_msec_y_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return sysfs_emit(buf, "%d\n", config->write_delay_msec_y); +} +static DEVICE_ATTR_RW(config_write_delay_msec_y); + +static ssize_t config_enable_busy_alloc_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int ret; + int val; + + ret = kstrtoint(buf, 10, &val); + if (ret) + return ret; + + test_dev_config_lock(test_dev); + config->enable_busy_alloc = val; + test_dev_config_unlock(test_dev); + + return count; +} + +static ssize_t config_enable_busy_alloc_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sysfs_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return sysfs_emit(buf, "%d\n", config->enable_busy_alloc); +} +static DEVICE_ATTR_RW(config_enable_busy_alloc); + +#define TEST_SYSFS_DEV_ATTR(name) (&dev_attr_##name.attr) + +static struct attribute *test_dev_attrs[] = { + /* Generic driver knobs go here */ + TEST_SYSFS_DEV_ATTR(config), + TEST_SYSFS_DEV_ATTR(reset), + + /* These are used to test sysfs */ + TEST_SYSFS_DEV_ATTR(test_dev_x), + TEST_SYSFS_DEV_ATTR(test_dev_y), + + /* + * These are configuration knobs to modify how we test sysfs when + * doing reads / stores. + */ + TEST_SYSFS_DEV_ATTR(config_enable_lock), + TEST_SYSFS_DEV_ATTR(config_enable_lock_on_rmmod), + TEST_SYSFS_DEV_ATTR(config_use_rtnl_lock), + TEST_SYSFS_DEV_ATTR(config_write_delay_msec_y), + TEST_SYSFS_DEV_ATTR(config_enable_busy_alloc), + + NULL, +}; + +ATTRIBUTE_GROUPS(test_dev); + +static int sysfs_test_dev_alloc_miscdev(struct sysfs_test_device *test_dev) +{ + struct miscdevice *misc_dev; + + misc_dev = &test_dev->misc_dev; + misc_dev->minor = MISC_DYNAMIC_MINOR; + misc_dev->name = kasprintf(GFP_KERNEL, "test_sysfs%d", test_dev->dev_idx); + if (!misc_dev->name) { + pr_err("Cannot alloc misc_dev->name\n"); + return -ENOMEM; + } + misc_dev->groups = test_dev_groups; + + return 0; +} + +static int testdev_open(struct block_device *bdev, fmode_t mode) +{ + return -EINVAL; +} + +static void testdev_submit_bio(struct bio *bio) +{ +} + +static void testdev_slot_free_notify(struct block_device *bdev, + unsigned long index) +{ +} + +static int testdev_rw_page(struct block_device *bdev, sector_t sector, + struct page *page, unsigned int op) +{ + return -EOPNOTSUPP; +} + +static const struct block_device_operations sysfs_testdev_ops = { + .open = testdev_open, + .submit_bio = testdev_submit_bio, + .swap_slot_free_notify = testdev_slot_free_notify, + .rw_page = testdev_rw_page, + .owner = THIS_MODULE +}; + +static int sysfs_test_dev_alloc_blockdev(struct sysfs_test_device *test_dev) +{ + int ret = -ENOMEM; + + test_dev->disk = blk_alloc_disk(NUMA_NO_NODE); + if (!test_dev->disk) { + pr_err("Error allocating disk structure for device %d\n", + test_dev->dev_idx); + goto out; + } + + test_dev->disk->major = sysfs_test_major; + test_dev->disk->first_minor = test_dev->dev_idx + 1; + test_dev->disk->fops = &sysfs_testdev_ops; + test_dev->disk->private_data = test_dev; + snprintf(test_dev->disk->disk_name, sizeof(test_dev->disk->disk_name), + "test_sysfs%d", test_dev->dev_idx); + set_capacity(test_dev->disk, 0); + blk_queue_flag_set(QUEUE_FLAG_NONROT, test_dev->disk->queue); + blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, test_dev->disk->queue); + blk_queue_physical_block_size(test_dev->disk->queue, PAGE_SIZE); + blk_queue_max_discard_sectors(test_dev->disk->queue, UINT_MAX); + blk_queue_flag_set(QUEUE_FLAG_DISCARD, test_dev->disk->queue); + + return 0; +out: + return ret; +} + +static struct sysfs_test_device *alloc_test_dev_sysfs(int idx) +{ + struct sysfs_test_device *test_dev; + int ret; + + switch (test_devtype) { + case TESTDEV_TYPE_MISC: + fallthrough; + case TESTDEV_TYPE_BLOCK: + break; + default: + return NULL; + } + + test_dev = kzalloc(sizeof(struct sysfs_test_device), GFP_KERNEL); + if (!test_dev) + goto err_out; + + mutex_init(&test_dev->config_mutex); + test_dev->dev_idx = idx; + test_dev->devtype = test_devtype; + + if (test_dev->devtype == TESTDEV_TYPE_MISC) { + ret = sysfs_test_dev_alloc_miscdev(test_dev); + if (ret) + goto err_out_free; + } else if (test_dev->devtype == TESTDEV_TYPE_BLOCK) { + ret = sysfs_test_dev_alloc_blockdev(test_dev); + if (ret) + goto err_out_free; + } + return test_dev; + +err_out_free: + kfree(test_dev); + test_dev = NULL; +err_out: + return NULL; +} + +static int register_test_dev_sysfs_misc(struct sysfs_test_device *test_dev) +{ + int ret; + + ret = misc_register(&test_dev->misc_dev); + if (ret) + return ret; + + test_dev->dev = test_dev->misc_dev.this_device; + + return 0; +} + +static int register_test_dev_sysfs_block(struct sysfs_test_device *test_dev) +{ + int ret; + + ret = device_add_disk(NULL, test_dev->disk, test_dev_groups); + if (ret) { + blk_cleanup_disk(test_dev->disk); + return ret; + } + + test_dev->dev = disk_to_dev(test_dev->disk); + + return 0; +} + +static struct sysfs_test_device *register_test_dev_sysfs(void) +{ + struct sysfs_test_device *test_dev = NULL; + int ret; + + test_dev = alloc_test_dev_sysfs(0); + if (!test_dev) + goto out; + + if (test_dev->devtype == TESTDEV_TYPE_MISC) { + ret = register_test_dev_sysfs_misc(test_dev); + if (ret) { + pr_err("could not register misc device: %d\n", ret); + goto out_free_dev; + } + } else if (test_dev->devtype == TESTDEV_TYPE_BLOCK) { + ret = register_test_dev_sysfs_block(test_dev); + if (ret) { + pr_err("could not register block device: %d\n", ret); + goto out_free_dev; + } + } + + dev_info(test_dev->dev, "interface ready\n"); + +out: + return test_dev; +out_free_dev: + free_test_dev_sysfs(test_dev); + return NULL; +} + +static struct sysfs_test_device *register_test_dev_set_config(void) +{ + struct sysfs_test_device *test_dev; + struct test_config *config; + + test_dev = register_test_dev_sysfs(); + if (!test_dev) + return NULL; + + config = &test_dev->config; + + if (enable_lock) + config->enable_lock = true; + if (enable_lock_on_rmmod) + config->enable_lock_on_rmmod = true; + if (use_rtnl_lock) + config->use_rtnl_lock = true; + if (enable_busy_alloc) + config->enable_busy_alloc = true; + + config->write_delay_msec_y = write_delay_msec_y; + test_sysfs_reset_vals(test_dev); + + return test_dev; +} + +static void unregister_test_dev_sysfs_misc(struct sysfs_test_device *test_dev) +{ + misc_deregister(&test_dev->misc_dev); +} + +static void unregister_test_dev_sysfs_block(struct sysfs_test_device *test_dev) +{ + del_gendisk(test_dev->disk); + blk_cleanup_disk(test_dev->disk); +} + +static void unregister_test_dev_sysfs(struct sysfs_test_device *test_dev) +{ + test_dev_config_lock_rmmod(test_dev); + + dev_info(test_dev->dev, "removing interface\n"); + + if (test_dev->devtype == TESTDEV_TYPE_MISC) + unregister_test_dev_sysfs_misc(test_dev); + else if (test_dev->devtype == TESTDEV_TYPE_BLOCK) + unregister_test_dev_sysfs_block(test_dev); + + test_dev_config_unlock_rmmod(test_dev); + + free_test_dev_sysfs(test_dev); +} + +static struct dentry *debugfs_dir; + +/* When read represents how many times we have reset the first_test_dev */ +static u8 reset_first_test_dev; + +static ssize_t read_reset_first_test_dev(struct file *file, + char __user *user_buf, + size_t count, loff_t *ppos) +{ + ssize_t len; + char buf[32]; + + reset_first_test_dev++; + len = sprintf(buf, "%d\n", reset_first_test_dev); + return simple_read_from_buffer(user_buf, count, ppos, buf, len); +} + +static ssize_t write_reset_first_test_dev(struct file *file, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + if (!first_test_dev) { + module_put(THIS_MODULE); + return -ENODEV; + } + + dev_info(first_test_dev->dev, "going to reset first interface ...\n"); + + unregister_test_dev_sysfs(first_test_dev); + first_test_dev = register_test_dev_set_config(); + + dev_info(first_test_dev->dev, "first interface reset complete\n"); + + module_put(THIS_MODULE); + + return count; +} + +static const struct file_operations fops_reset_first_test_dev = { + .read = read_reset_first_test_dev, + .write = write_reset_first_test_dev, + .open = simple_open, + .owner = THIS_MODULE, + .llseek = default_llseek, +}; + +static int __init test_sysfs_init(void) +{ + first_test_dev = register_test_dev_set_config(); + if (!first_test_dev) + return -ENOMEM; + + if (!enable_debugfs) + return 0; + + debugfs_dir = debugfs_create_dir("test_sysfs", NULL); + if (!debugfs_dir) { + unregister_test_dev_sysfs(first_test_dev); + return -ENOMEM; + } + + debugfs_create_file("reset_first_test_dev", 0600, debugfs_dir, + NULL, &fops_reset_first_test_dev); + return 0; +} +module_init(test_sysfs_init); + +static void __exit test_sysfs_exit(void) +{ + if (enable_debugfs) + debugfs_remove(debugfs_dir); + if (delay_rmmod_ms) + msleep(delay_rmmod_ms); + unregister_test_dev_sysfs(first_test_dev); + if (enable_verbose_rmmod) + pr_info("unregister_test_dev_sysfs() completed\n"); + first_test_dev = NULL; +} +module_exit(test_sysfs_exit); + +MODULE_AUTHOR("Luis Chamberlain "); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/sysfs/Makefile b/tools/testing/selftests/sysfs/Makefile new file mode 100644 index 000000000000..fde99caa2338 --- /dev/null +++ b/tools/testing/selftests/sysfs/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0-only +# Makefile for sysfs selftests. + +# No binaries, but make sure arg-less "make" doesn't trigger "run_tests". +all: + +TEST_PROGS := sysfs.sh + +include ../lib.mk + +# Nothing to clean up. +clean: diff --git a/tools/testing/selftests/sysfs/config b/tools/testing/selftests/sysfs/config new file mode 100644 index 000000000000..9196f452ecd5 --- /dev/null +++ b/tools/testing/selftests/sysfs/config @@ -0,0 +1,2 @@ +CONFIG_SYSFS=m +CONFIG_TEST_SYSFS=m diff --git a/tools/testing/selftests/sysfs/settings b/tools/testing/selftests/sysfs/settings new file mode 100644 index 000000000000..ae36db2b3200 --- /dev/null +++ b/tools/testing/selftests/sysfs/settings @@ -0,0 +1 @@ +timeout=200 diff --git a/tools/testing/selftests/sysfs/sysfs.sh b/tools/testing/selftests/sysfs/sysfs.sh new file mode 100755 index 000000000000..802651d78427 --- /dev/null +++ b/tools/testing/selftests/sysfs/sysfs.sh @@ -0,0 +1,1197 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (C) 2021 Luis Chamberlain +# +# This performs a series tests against the sysfs filesystem. + +# Kselftest framework requirement - SKIP code is 4. +ksft_skip=4 + +TEST_NAME="sysfs" +TEST_DRIVER="test_${TEST_NAME}" +TEST_DIR=$(dirname $0) +TEST_FILE=$(mktemp) + +# This represents +# +# TEST_ID:TEST_COUNT:ENABLED:TARGET +# +# TEST_ID: is the test id number +# TEST_COUNT: number of times we should run the test +# ENABLED: 1 if enabled, 0 otherwise +# TARGET: test target file required on the test_sysfs module +# +# Once these are enabled please leave them as-is. Write your own test, +# we have tons of space. +ALL_TESTS="0001:3:1:test_dev_x:misc" +ALL_TESTS="$ALL_TESTS 0002:3:1:test_dev_y:misc" +ALL_TESTS="$ALL_TESTS 0003:3:1:test_dev_x:misc" +ALL_TESTS="$ALL_TESTS 0004:3:1:test_dev_y:misc" +ALL_TESTS="$ALL_TESTS 0005:1:1:test_dev_x:misc" +ALL_TESTS="$ALL_TESTS 0006:1:1:test_dev_y:misc" +ALL_TESTS="$ALL_TESTS 0007:1:1:test_dev_y:misc" +ALL_TESTS="$ALL_TESTS 0008:1:1:test_dev_x:misc" +ALL_TESTS="$ALL_TESTS 0009:1:1:test_dev_y:misc" +ALL_TESTS="$ALL_TESTS 0010:1:1:test_dev_y:misc" +ALL_TESTS="$ALL_TESTS 0011:1:1:test_dev_x:misc" +ALL_TESTS="$ALL_TESTS 0012:1:1:test_dev_y:misc" +ALL_TESTS="$ALL_TESTS 0013:1:1:test_dev_y:misc" +ALL_TESTS="$ALL_TESTS 0014:3:1:test_dev_x:block" # block equivalent set +ALL_TESTS="$ALL_TESTS 0015:3:1:test_dev_x:block" +ALL_TESTS="$ALL_TESTS 0016:3:1:test_dev_x:block" +ALL_TESTS="$ALL_TESTS 0017:3:1:test_dev_y:block" +ALL_TESTS="$ALL_TESTS 0018:1:1:test_dev_x:block" +ALL_TESTS="$ALL_TESTS 0019:1:1:test_dev_y:block" +ALL_TESTS="$ALL_TESTS 0020:1:1:test_dev_y:block" +ALL_TESTS="$ALL_TESTS 0021:1:1:test_dev_x:block" +ALL_TESTS="$ALL_TESTS 0022:1:1:test_dev_y:block" +ALL_TESTS="$ALL_TESTS 0023:1:1:test_dev_y:block" +ALL_TESTS="$ALL_TESTS 0024:1:1:test_dev_x:block" +ALL_TESTS="$ALL_TESTS 0025:1:1:test_dev_y:block" +ALL_TESTS="$ALL_TESTS 0026:1:1:test_dev_y:block" +ALL_TESTS="$ALL_TESTS 0027:1:0:test_dev_x:block" # deadlock test +ALL_TESTS="$ALL_TESTS 0028:1:0:test_dev_x:block" # deadlock test with rntl_lock + +allow_user_defaults() +{ + if [ -z $DIR ]; then + case $TEST_DEV_TYPE in + misc) + DIR="/sys/devices/virtual/misc/${TEST_DRIVER}0" + ;; + block) + DIR="/sys/devices/virtual/block/${TEST_DRIVER}0" + ;; + *) + DIR="/sys/devices/virtual/misc/${TEST_DRIVER}0" + ;; + esac + fi + case $TEST_DEV_TYPE in + misc) + MODPROBE_TESTDEV_TYPE="" + ;; + block) + MODPROBE_TESTDEV_TYPE="devtype=1" + ;; + *) + MODPROBE_TESTDEV_TYPE="" + ;; + esac + if [ -z $SYSFS_DEBUGFS_DIR ]; then + SYSFS_DEBUGFS_DIR="/sys/kernel/debug/test_sysfs" + fi + if [ -z $PAGE_SIZE ]; then + PAGE_SIZE=$(getconf PAGESIZE) + fi + if [ -z $MAX_DIGITS ]; then + MAX_DIGITS=$(($PAGE_SIZE/8)) + fi + if [ -z $INT_MAX ]; then + INT_MAX=$(getconf INT_MAX) + fi + if [ -z $UINT_MAX ]; then + UINT_MAX=$(getconf UINT_MAX) + fi +} + +test_reqs() +{ + uid=$(id -u) + if [ $uid -ne 0 ]; then + echo $msg must be run as root >&2 + exit $ksft_skip + fi + + if ! which modprobe 2> /dev/null > /dev/null; then + echo "$0: You need modprobe installed" >&2 + exit $ksft_skip + fi + if ! which getconf 2> /dev/null > /dev/null; then + echo "$0: You need getconf installed" + exit $ksft_skip + fi + if ! which diff 2> /dev/null > /dev/null; then + echo "$0: You need diff installed" + exit $ksft_skip + fi + if ! which perl 2> /dev/null > /dev/null; then + echo "$0: You need perl installed" + exit $ksft_skip + fi +} + +call_modprobe() +{ + modprobe $TEST_DRIVER $MODPROBE_TESTDEV_TYPE $FIRST_MODPROBE_ARGS $MODPROBE_ARGS + return $? +} + +modprobe_reset() +{ + modprobe -q -r $TEST_DRIVER + call_modprobe + return $? +} + +modprobe_reset_enable_debugfs() +{ + FIRST_MODPROBE_ARGS="enable_debugfs=1" + modprobe_reset + unset FIRST_MODPROBE_ARGS +} + +modprobe_reset_enable_lock_on_rmmod() +{ + FIRST_MODPROBE_ARGS="enable_lock=1 enable_lock_on_rmmod=1 enable_verbose_writes=1" + modprobe_reset + unset FIRST_MODPROBE_ARGS +} + +modprobe_reset_enable_rtnl_lock_on_rmmod() +{ + FIRST_MODPROBE_ARGS="enable_lock=1 use_rtnl_lock=1 enable_lock_on_rmmod=1" + FIRST_MODPROBE_ARGS="$FIRST_MODPROBE_ARGS enable_verbose_writes=1" + modprobe_reset + unset FIRST_MODPROBE_ARGS +} + +load_req_mod() +{ + modprobe_reset + if [ ! -d $DIR ]; then + if ! modprobe -q -n $TEST_DRIVER; then + echo "$0: module $TEST_DRIVER not found [SKIP]" + echo "You must set CONFIG_TEST_SYSFS=m in your kernel" >&2 + exit $ksft_skip + fi + call_modprobe + if [ $? -ne 0 ]; then + echo "$0: modprobe $TEST_DRIVER failed." + exit + fi + fi +} + +config_reset() +{ + if ! echo -n "1" >"$DIR"/reset; then + echo "$0: reset should have worked" >&2 + exit 1 + fi +} + +debugfs_reset_first_test_dev_ignore_errors() +{ + echo -n "1" >"$SYSFS_DEBUGFS_DIR"/reset_first_test_dev +} + +set_orig() +{ + if [[ ! -z $TARGET ]] && [[ ! -z $ORIG ]]; then + if [ -f ${TARGET} ]; then + echo "${ORIG}" > "${TARGET}" + fi + fi +} + +set_test() +{ + echo "${TEST_STR}" > "${TARGET}" +} + +set_test_ignore_errors() +{ + echo "${TEST_STR}" > "${TARGET}" 2> /dev/null +} + +verify() +{ + local seen + seen=$(cat "$1") + target_short=$(basename $TARGET) + case $target_short in + test_dev_x) + if [ "${seen}" != "${TEST_STR}" ]; then + return 1 + fi + ;; + test_dev_y) + DIRNAME=$(dirname $1) + EXPECTED_RESULT="" + # If our target was the test file then what we write to it + # is the same as what that we expect when we read from it. + # When we write to test_dev_y directly though we expect + # a computed value which is driver specific. + if [[ "$DIRNAME" == "/tmp" ]]; then + let EXPECTED_RESULT="${TEST_STR}" + else + x=$(cat ${DIR}/test_dev_x) + let EXPECTED_RESULT="$x+${TEST_STR}+7" + fi + + if [[ "${seen}" != "${EXPECTED_RESULT}" ]]; then + return 1 + fi + ;; + *) + echo "Unsupported target type update test script: $target_short" + exit 1 + esac + return 0 +} + +verify_diff_w() +{ + echo "$TEST_STR" | diff -q -w -u - $1 > /dev/null + return $? +} + +test_rc() +{ + if [[ $rc != 0 ]]; then + echo "Failed test, return value: $rc" >&2 + exit $rc + fi +} + +test_finish() +{ + set_orig + rm -f "${TEST_FILE}" + + if [ ! -z ${old_strict} ]; then + echo ${old_strict} > ${WRITES_STRICT} + fi + exit $rc +} + +# kernfs requires us to write everything we want in one shot because +# There is no easy way for us to know if userspace is only doing a partial +# write, so we don't support them. We expect the entire buffer to come on +# the first write. If you're writing a value, first read the file, +# modify only the value you're changing, then write entire buffer back. +# Since we are only testing digits we just full single writes and old stuff. +# For more details, refer to kernfs_fop_write_iter(). +run_numerictests_single_write() +{ + echo "== Testing sysfs behavior against ${TARGET} ==" + + rc=0 + + echo -n "Writing test file ... " + echo "${TEST_STR}" > "${TEST_FILE}" + if ! verify "${TEST_FILE}"; then + echo "FAIL" >&2 + exit 1 + else + echo "ok" + fi + + echo -n "Checking the sysfs file is not set to test value ... " + if verify "${TARGET}"; then + echo "FAIL" >&2 + exit 1 + else + echo "ok" + fi + + echo -n "Writing to sysfs file from shell ... " + set_test + if ! verify "${TARGET}"; then + echo "FAIL" >&2 + exit 1 + else + echo "ok" + fi + + echo -n "Resetting sysfs file to original value ... " + set_orig + if verify "${TARGET}"; then + echo "FAIL" >&2 + exit 1 + else + echo "ok" + fi + + # Now that we've validated the sanity of "set_test" and "set_orig", + # we can use those functions to set starting states before running + # specific behavioral tests. + + echo -n "Writing to the entire sysfs file in a single write ... " + set_orig + dd if="${TEST_FILE}" of="${TARGET}" bs=4096 2>/dev/null + if ! verify "${TARGET}"; then + echo "FAIL" >&2 + rc=1 + else + echo "ok" + fi + + echo -n "Writing to the sysfs file with multiple long writes ... " + set_orig + (perl -e 'print "A" x 50;'; echo "${TEST_STR}") | \ + dd of="${TARGET}" bs=50 2>/dev/null + if verify "${TARGET}"; then + echo "FAIL" >&2 + rc=1 + else + echo "ok" + fi + test_rc +} + +reset_vals() +{ + echo -n 3 > $DIR/test_dev_x + echo -n 4 > $DIR/test_dev_x +} + +check_failure() +{ + echo -n "Testing that $1 fails as expected..." + reset_vals + TEST_STR="$1" + orig="$(cat $TARGET)" + echo -n "$TEST_STR" > $TARGET 2> /dev/null + + # write should fail and $TARGET should retain its original value + if [ $? = 0 ] || [ "$(cat $TARGET)" != "$orig" ]; then + echo "FAIL" >&2 + rc=1 + else + echo "ok" + fi + test_rc +} + +load_modreqs() +{ + export TEST_DEV_TYPE=$(get_test_type $1) + unset DIR + allow_user_defaults + load_req_mod +} + +target_exists() +{ + TARGET="${DIR}/$1" + TEST_ID="$2" + + if [ ! -f ${TARGET} ] ; then + echo "Target for test $TEST_ID: $TARGET does not exist, skipping test ..." + return 0 + fi + return 1 +} + +config_enable_lock() +{ + if ! echo -n 1 > $DIR/config_enable_lock; then + echo "$0: Unable to enable locks" >&2 + exit 1 + fi +} + +config_write_delay_msec_y() +{ + if ! echo -n $1 > $DIR/config_write_delay_msec_y ; then + echo "$0: Unable to set write_delay_msec_y to $1" >&2 + exit 1 + fi +} + +# Default filter for dmesg scanning. +# Ignore lockdep complaining about its own bugginess when scanning dmesg +# output, because we shouldn't be failing filesystem tests on account of +# lockdep. +_check_dmesg_filter() +{ + egrep -v -e "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low" \ + -e "BUG: MAX_STACK_TRACE_ENTRIES too low" +} + +check_dmesg() +{ + # filter out intentional WARNINGs or Oopses + local filter=${1:-_check_dmesg_filter} + + _dmesg_since_test_start | $filter >$seqres.dmesg + egrep -q -e "kernel BUG at" \ + -e "WARNING:" \ + -e "\bBUG:" \ + -e "Oops:" \ + -e "possible recursive locking detected" \ + -e "Internal error" \ + -e "(INFO|ERR): suspicious RCU usage" \ + -e "INFO: possible circular locking dependency detected" \ + -e "general protection fault:" \ + -e "BUG .* remaining" \ + -e "UBSAN:" \ + $seqres.dmesg + if [ $? -eq 0 ]; then + echo "something found in dmesg (see $seqres.dmesg)" + return 1 + else + if [ "$KEEP_DMESG" != "yes" ]; then + rm -f $seqres.dmesg + fi + return 0 + fi +} + +log_kernel_fstest_dmesg() +{ + export FSTYP="$1" + export seqnum="$FSTYP/$2" + export date_time=$(date +"%F %T") + echo "run fstests $seqnum at $date_time" > /dev/kmsg +} + +modprobe_loop() +{ + while true; do + call_modprobe > /dev/null 2>&1 + modprobe -r $TEST_DRIVER > /dev/null 2>&1 + done > /dev/null 2>&1 +} + +write_loop() +{ + while true; do + set_test_ignore_errors > /dev/null 2>&1 + TEST_STR=$(( $TEST_STR + 1 )) + done > /dev/null 2>&1 +} + +write_loop_reset() +{ + while true; do + set_test_ignore_errors > /dev/null 2>&1 + debugfs_reset_first_test_dev_ignore_errors > /dev/null 2>&1 + done > /dev/null 2>&1 +} + +write_loop_bg() +{ + BG_WRITES=1000 > /dev/null 2>&1 + while true; do + for i in $(seq 1 $BG_WRITES); do + set_test_ignore_errors > /dev/null 2>&1 & + TEST_STR=$(( $TEST_STR + 1 )) + done > /dev/null 2>&1 + wait + done > /dev/null 2>&1 + wait +} + +reset_loop() +{ + while true; do + debugfs_reset_first_test_dev_ignore_errors > /dev/null 2>&1 + done > /dev/null 2>&1 +} + +kill_trigger_loop() +{ + + local my_first_loop_pid=$1 + local my_second_loop_pid=$2 + local my_sleep_max=$3 + local my_loop=0 + + while true; do + sleep 1 + if [[ $my_loop -ge $my_sleep_max ]]; then + break + fi + let my_loop=$my_loop+1 + done + + kill -s TERM $my_first_loop_pid 2>&1 > /dev/null + kill -s TERM $my_second_loop_pid 2>&1 > /dev/null +} + +_dmesg_since_test_start() +{ + # search the dmesg log of last run of $seqnum for possible failures + # use sed \cregexpc address type, since $seqnum contains "/" + dmesg | tac | sed -ne "0,\#run fstests $seqnum at $date_time#p" | tac +} + +sysfs_test_0001() +{ + TARGET="${DIR}/$(get_test_target 0001)" + config_reset + reset_vals + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + + run_numerictests_single_write +} + +sysfs_test_0002() +{ + TARGET="${DIR}/$(get_test_target 0002)" + config_reset + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + + run_numerictests_single_write +} + +sysfs_test_0003() +{ + TARGET="${DIR}/$(get_test_target 0003)" + config_reset + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + + config_enable_lock + + run_numerictests_single_write +} + +sysfs_test_0004() +{ + TARGET="${DIR}/$(get_test_target 0004)" + config_reset + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + + config_enable_lock + + run_numerictests_single_write +} + +sysfs_test_0005() +{ + TARGET="${DIR}/$(get_test_target 0005)" + modprobe_reset + config_reset + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop writing x while loading/unloading the module... " + + modprobe_loop & + modprobe_pid=$! + + write_loop & + write_pid=$! + + kill_trigger_loop $modprobe_pid $write_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0006() +{ + TARGET="${DIR}/$(get_test_target 0006)" + modprobe_reset + config_reset + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop writing y while loading/unloading the module... " + modprobe_loop & + modprobe_pid=$! + + write_loop & + write_pid=$! + + kill_trigger_loop $modprobe_pid $write_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0007() +{ + TARGET="${DIR}/$(get_test_target 0007)" + modprobe_reset + config_reset + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop writing y with a larger delay while loading/unloading the module... " + + MODPROBE_ARGS="write_delay_msec_y=1500" + modprobe_loop > /dev/null 2>&1 & + modprobe_pid=$! + unset MODPROBE_ARGS + + write_loop & + write_pid=$! + + kill_trigger_loop $modprobe_pid $write_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0008() +{ + TARGET="${DIR}/$(get_test_target 0008)" + modprobe_reset + config_reset + reset_vals + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop busy writing x while loading/unloading the module... " + + modprobe_loop > /dev/null 2>&1 & + modprobe_pid=$! + + write_loop_bg > /dev/null 2>&1 & + write_pid=$! + + kill_trigger_loop $modprobe_pid $write_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0009() +{ + TARGET="${DIR}/$(get_test_target 0009)" + modprobe_reset + config_reset + reset_vals + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop busy writing y while loading/unloading the module... " + + modprobe_loop > /dev/null 2>&1 & + modprobe_pid=$! + + write_loop_bg > /dev/null 2>&1 & + write_pid=$! + + kill_trigger_loop $modprobe_pid $write_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0010() +{ + TARGET="${DIR}/$(get_test_target 0010)" + modprobe_reset + config_reset + reset_vals + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop busy writing y with a larger delay while loading/unloading the module... " + modprobe -q -r $TEST_DRIVER > /dev/null 2>&1 + + MODPROBE_ARGS="write_delay_msec_y=1500" + modprobe_loop > /dev/null 2>&1 & + modprobe_pid=$! + unset MODPROBE_ARGS + + write_loop_bg > /dev/null 2>&1 & + write_pid=$! + + kill_trigger_loop $modprobe_pid $write_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0011() +{ + TARGET="${DIR}/$(get_test_target 0011)" + modprobe_reset_enable_debugfs + config_reset + reset_vals + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop writing x and resetting ... " + + write_loop > /dev/null 2>&1 & + write_pid=$! + + reset_loop > /dev/null 2>&1 & + reset_pid=$! + + kill_trigger_loop $write_pid $reset_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0012() +{ + TARGET="${DIR}/$(get_test_target 0012)" + modprobe_reset_enable_debugfs + config_reset + reset_vals + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop writing y and resetting ... " + + write_loop > /dev/null 2>&1 & + write_pid=$! + + reset_loop > /dev/null 2>&1 & + reset_pid=$! + + kill_trigger_loop $write_pid $reset_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0013() +{ + TARGET="${DIR}/$(get_test_target 0013)" + modprobe_reset_enable_debugfs + config_reset + reset_vals + config_write_delay_msec_y 1500 + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Loop writing y with a larger delay and resetting ... " + + write_loop > /dev/null 2>&1 & + write_pid=$! + + reset_loop > /dev/null 2>&1 & + reset_pid=$! + + kill_trigger_loop $write_pid $reset_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0014() +{ + sysfs_test_0001 +} + +sysfs_test_0015() +{ + sysfs_test_0002 +} + +sysfs_test_0016() +{ + sysfs_test_0003 +} + +sysfs_test_0017() +{ + sysfs_test_0004 +} + +sysfs_test_0018() +{ + sysfs_test_0005 +} + +sysfs_test_0019() +{ + sysfs_test_0006 +} + +sysfs_test_0020() +{ + sysfs_test_0007 +} + +sysfs_test_0021() +{ + sysfs_test_0008 +} + +sysfs_test_0022() +{ + sysfs_test_0009 +} + +sysfs_test_0023() +{ + sysfs_test_0010 +} + +sysfs_test_0024() +{ + sysfs_test_0011 +} + +sysfs_test_0025() +{ + sysfs_test_0012 +} + +sysfs_test_0026() +{ + sysfs_test_0013 +} + +sysfs_test_0027() +{ + TARGET="${DIR}/$(get_test_target 0027)" + modprobe_reset_enable_lock_on_rmmod + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Test for possible rmmod deadlock while writing x ... " + + write_loop > /dev/null 2>&1 & + write_pid=$! + + MODPROBE_ARGS="enable_lock=1 enable_lock_on_rmmod=1 enable_verbose_writes=1" + modprobe_loop > /dev/null 2>&1 & + modprobe_pid=$! + unset MODPROBE_ARGS + + kill_trigger_loop $modprobe_pid $write_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +sysfs_test_0028() +{ + TARGET="${DIR}/$(get_test_target 0028)" + modprobe_reset_enable_lock_on_rmmod + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + WAIT_TIME=2 + + echo -n "Test for possible rmmod deadlock using rtnl_lock while writing x ... " + + write_loop > /dev/null 2>&1 & + write_pid=$! + + MODPROBE_ARGS="enable_lock=1 enable_lock_on_rmmod=1 use_rtnl_lock=1 enable_verbose_writes=1" + modprobe_loop > /dev/null 2>&1 & + modprobe_pid=$! + unset MODPROBE_ARGS + + kill_trigger_loop $modprobe_pid $write_pid $WAIT_TIME > /dev/null 2>&1 & + kill_pid=$! + + wait $kill_pid > /dev/null 2>&1 + + if [[ $? -eq 0 ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +test_gen_desc() +{ + echo -n "$1 x $(get_test_count $1)" +} + +list_tests() +{ + echo "Test ID list:" + echo + echo "TEST_ID x NUM_TEST" + echo "TEST_ID: Test ID" + echo "NUM_TESTS: Number of recommended times to run the test" + echo + echo "$(test_gen_desc 0001) - misc test writing x in different ways" + echo "$(test_gen_desc 0002) - misc test writing y in different ways" + echo "$(test_gen_desc 0003) - misc test writing x in different ways using a mutex lock" + echo "$(test_gen_desc 0004) - misc test writing y in different ways using a mutex lock" + echo "$(test_gen_desc 0005) - misc test writing x load and remove the test_sysfs module" + echo "$(test_gen_desc 0006) - misc writing y load and remove the test_sysfs module" + echo "$(test_gen_desc 0007) - misc test writing y larger delay, load, remove test_sysfs" + echo "$(test_gen_desc 0008) - misc test busy writing x remove test_sysfs module" + echo "$(test_gen_desc 0009) - misc test busy writing y remove the test_sysfs module" + echo "$(test_gen_desc 0010) - misc test busy writing y larger delay, remove test_sysfs" + echo "$(test_gen_desc 0011) - misc test writing x and resetting device" + echo "$(test_gen_desc 0012) - misc test writing y and resetting device" + echo "$(test_gen_desc 0013) - misc test writing y with a larger delay and resetting device" + echo "$(test_gen_desc 0014) - block test writing x in different ways" + echo "$(test_gen_desc 0015) - block test writing y in different ways" + echo "$(test_gen_desc 0016) - block test writing x in different ways using a mutex lock" + echo "$(test_gen_desc 0017) - block test writing y in different ways using a mutex lock" + echo "$(test_gen_desc 0018) - block test writing x load and remove the test_sysfs module" + echo "$(test_gen_desc 0019) - block test writing y load and remove the test_sysfs module" + echo "$(test_gen_desc 0020) - block test writing y larger delay, load, remove test_sysfs" + echo "$(test_gen_desc 0021) - block test busy writing x remove the test_sysfs module" + echo "$(test_gen_desc 0022) - block test busy writing y remove the test_sysfs module" + echo "$(test_gen_desc 0023) - block test busy writing y larger delay, remove test_sysfs" + echo "$(test_gen_desc 0024) - block test writing x and resetting device" + echo "$(test_gen_desc 0025) - block test writing y and resetting device" + echo "$(test_gen_desc 0026) - block test writing y larger delay and resetting device" + echo "$(test_gen_desc 0027) - test rmmod deadlock while writing x ... " + echo "$(test_gen_desc 0028) - test rmmod deadlock using rtnl_lock while writing x ..." +} + +usage() +{ + NUM_TESTS=$(grep -o ' ' <<<"$ALL_TESTS" | grep -c .) + let NUM_TESTS=$NUM_TESTS+1 + MAX_TEST=$(printf "%04d\n" $NUM_TESTS) + echo "Usage: $0 [ -t <4-number-digit> ] | [ -w <4-number-digit> ] |" + echo " [ -s <4-number-digit> ] | [ -c <4-number-digit> " + echo " [ all ] [ -h | --help ] [ -l ]" + echo "" + echo "Valid tests: 0001-$MAX_TEST" + echo "" + echo " all Runs all tests (default)" + echo " -t Run test ID the number amount of times is recommended" + echo " -w Watch test ID run until it runs into an error" + echo " -c Run test ID once" + echo " -s Run test ID x test-count number of times" + echo " -l List all test ID list" + echo " -h|--help Help" + echo + echo "If an error every occurs execution will immediately terminate." + echo "If you are adding a new test try using -w first to" + echo "make sure the test passes a series of tests." + echo + echo Example uses: + echo + echo "$TEST_NAME.sh -- executes all tests" + echo "$TEST_NAME.sh -t 0002 -- Executes test ID 0002 number of times is recomended" + echo "$TEST_NAME.sh -w 0002 -- Watch test ID 0002 run until an error occurs" + echo "$TEST_NAME.sh -s 0002 -- Run test ID 0002 once" + echo "$TEST_NAME.sh -c 0002 3 -- Run test ID 0002 three times" + echo + list_tests + exit 1 +} + +test_num() +{ + re='^[0-9]+$' + if ! [[ $1 =~ $re ]]; then + usage + fi +} + +get_test_count() +{ + test_num $1 + TEST_NUM=$(echo $1 | sed 's/^0*//') + TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$TEST_NUM'}') + echo ${TEST_DATA} | awk -F":" '{print $2}' +} + +get_test_enabled() +{ + test_num $1 + TEST_NUM=$(echo $1 | sed 's/^0*//') + TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$TEST_NUM'}') + echo ${TEST_DATA} | awk -F":" '{print $3}' +} + +get_test_target() +{ + test_num $1 + TEST_NUM=$(echo $1 | sed 's/^0*//') + TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$TEST_NUM'}') + echo ${TEST_DATA} | awk -F":" '{print $4}' +} + +get_test_type() +{ + test_num $1 + TEST_NUM=$(echo $1 | sed 's/^0*//') + TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$TEST_NUM'}') + echo ${TEST_DATA} | awk -F":" '{print $5}' +} + +run_all_tests() +{ + for i in $ALL_TESTS ; do + TEST_ID=$(echo $i | awk -F":" '{print $1}') + ENABLED=$(get_test_enabled $TEST_ID) + TEST_COUNT=$(get_test_count $TEST_ID) + TEST_TARGET=$(get_test_target $TEST_ID) + if [[ $ENABLED -eq "1" ]]; then + test_case $TEST_ID $TEST_COUNT $TEST_TARGET + else + echo -n "Skipping test $TEST_ID as its disabled, likely " + echo "could crash your system ..." + fi + done +} + +watch_log() +{ + if [ $# -ne 3 ]; then + clear + fi + echo "Running test: $2 - run #$1" +} + +watch_case() +{ + i=0 + while [ 1 ]; do + if [ $# -eq 1 ]; then + test_num $1 + watch_log $i ${TEST_NAME}_test_$1 + log_kernel_fstest_dmesg sysfs $1 + RUN_TEST=${TEST_NAME}_test_$1 + $RUN_TEST + check_dmesg + if [[ $? -ne 0 ]]; then + exit 1 + fi + else + watch_log $i all + run_all_tests + fi + let i=$i+1 + done +} + +test_case() +{ + NUM_TESTS=$2 + + i=0 + + load_modreqs $1 + if target_exists $3 $1; then + return + fi + + while [[ $i -lt $NUM_TESTS ]]; do + test_num $1 + watch_log $i ${TEST_NAME}_test_$1 noclear + log_kernel_fstest_dmesg sysfs $1 + RUN_TEST=${TEST_NAME}_test_$1 + $RUN_TEST + let i=$i+1 + done + check_dmesg + if [[ $? -ne 0 ]]; then + exit 1 + fi +} + +parse_args() +{ + if [ $# -eq 0 ]; then + run_all_tests + else + if [[ "$1" = "all" ]]; then + run_all_tests + elif [[ "$1" = "-w" ]]; then + shift + watch_case $@ + elif [[ "$1" = "-t" ]]; then + shift + test_num $1 + test_case $1 $(get_test_count $1) $(get_test_target $1) + shift + elif [[ "$1" = "-c" ]]; then + shift + test_num $1 + test_num $2 + test_case $1 $2 $(get_test_target $1) + shift + shift + elif [[ "$1" = "-s" ]]; then + shift + test_case $1 1 $(get_test_target $1) + shift + elif [[ "$1" = "-l" ]]; then + list_tests + shift + elif [[ "$1" = "-h" || "$1" = "--help" ]]; then + usage + else + usage + fi + fi +} + +test_reqs +allow_user_defaults + +trap "test_finish" EXIT + +parse_args $@ + +exit 0 From patchwork Fri Oct 29 18:44:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 12593375 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE000C4321E for ; Fri, 29 Oct 2021 18:45:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7624610E5 for ; Fri, 29 Oct 2021 18:45:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231258AbhJ2Srw (ORCPT ); Fri, 29 Oct 2021 14:47:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230176AbhJ2Sri (ORCPT ); Fri, 29 Oct 2021 14:47:38 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9566C0613F5; Fri, 29 Oct 2021 11:45:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=daxyne+rgfhLB2iCcxtK7JtrdUqP/GkbwY1AJXraErc=; b=GH8/FI0J9w70bdbLZAUCrvL0xX LM5O7QvOlaZ6dNoRttdCgnL0gfbHheoYh66LtvrXWIa5gL6D2vrSx+5lrIiYixOpHJsobzVTQJ3o9 ty+o7VPTqW7XYO6LAh7+vq9BgXv3uAPaa/gjgs91woTxIg+Jp5WEdBdfhlIE5nqNUihx3gyvrquVD RDRBuAs3txx+w/Yc5zla9Sx2a6X9GpeDCG6U2NPEdFJVh5vB9zGR+wZaFwtN1YOXSYuZZLfFmODb4 EZoDfHnE2KyTKR31lEoOquFjPHkPzDmUN1v4F/Wfqlj4j8VXwcJylF6ZJYB7mPYISWhByILr49Ozb EnP1PntQ==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgWsA-00Bq0V-Eb; Fri, 29 Oct 2021 18:45:02 +0000 From: Luis Chamberlain To: tj@kernel.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, jeyu@kernel.org, shuah@kernel.org Cc: bvanassche@acm.org, dan.j.williams@intel.com, joe@perches.com, tglx@linutronix.de, mcgrof@kernel.org, keescook@chromium.org, rostedt@goodmis.org, minchan@kernel.org, linux-spdx@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 4/6] kernfs: add initial failure injection support Date: Fri, 29 Oct 2021 11:44:58 -0700 Message-Id: <20211029184500.2821444-5-mcgrof@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211029184500.2821444-1-mcgrof@kernel.org> References: <20211029184500.2821444-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This adds initial failure injection support to kernfs. We start off with debug knobs which when enabled allow test drivers, such as test_sysfs, to then make use of these to try to force certain difficult races to take place with a high degree of certainty. This only adds runtime code *iff* the new bool CONFIG_FAIL_KERNFS_KNOBS is enabled in your kernel. If you don't have this enabled this provides no new functional. When CONFIG_FAIL_KERNFS_KNOBS is disabled the new routine may_wait_kernfs_debug() ends up being transformed to a no-op and so the compiler should optimize these out as dead code producing no new effective binary changes. We start off with enabling failure injections in kernfs by allowing us to alter the way kernfs_fop_write_iter() behaves. We allow for the routine kernfs_fop_write_iter() to wait for a certain condition in the kernel to occur, after which it will sleep a configurable amount of time. This lets kernfs users to time exactly when it want kernfs_fop_write_iter() to complete, allowing for developing race conditions and test for correctness in kernfs. You'd boot with this enabled on your kernel command line: fail_kernfs_fop_write_iter=1,100,0,1 The values are , we don't care for size, so for now we ignore it. The above ensures a failure will trigger only once. *How* we allow for this routine to change behaviour is left to knobs we expose under debugfs: # ls -1 /sys/kernel/debug/fail_kernfs/config_fail_kernfs_fop_write_iter/ wait_after_active wait_after_mutex wait_at_start wait_before_mutex A debugfs entry also exists to allow us to sleep a configurabler amount of time after the completion: /sys/kernel/debug/fail_kernfs/sleep_after_wait_ms These two sets of knobs allow us to construct races and demonstrate how the kernfs active reference should suffice to protect against races. Enabling CONFIG_FAULT_INJECTION_DEBUG_FS enables us to configure the different fault injection parameters for the new fail_kernfs_fop_write_iter fault injection at run time: ls -1 /sys/kernel/debug/fail_kernfs/fail_kernfs_fop_write_iter/ interval probability space task-filter times verbose verbose_ratelimit_burst verbose_ratelimit_interval_ms Signed-off-by: Luis Chamberlain --- .../fault-injection/fault-injection.rst | 50 ++++++++++ MAINTAINERS | 2 +- fs/kernfs/Makefile | 1 + fs/kernfs/fault_inject.c | 93 +++++++++++++++++++ fs/kernfs/file.c | 9 ++ fs/kernfs/kernfs-internal.h | 70 ++++++++++++++ include/linux/kernfs.h | 5 + lib/Kconfig.debug | 10 ++ 8 files changed, 239 insertions(+), 1 deletion(-) create mode 100644 fs/kernfs/fault_inject.c diff --git a/Documentation/fault-injection/fault-injection.rst b/Documentation/fault-injection/fault-injection.rst index 4a25c5eb6f07..af05f285b441 100644 --- a/Documentation/fault-injection/fault-injection.rst +++ b/Documentation/fault-injection/fault-injection.rst @@ -28,6 +28,19 @@ Available fault injection capabilities injects kernel RPC client and server failures. +- fail_kernfs_fop_write_iter + + Allows for failures to be enabled inside kernfs_fop_write_iter(). Enabling + this does not immediately enable any errors to occur. You must configure + how you want this routine to fail or change behaviour by using the respective + debugfs knobs for it documented below under + /sys/kernel/debug/fail_kernfs/config_fail_kernfs_fop_write_iter/ + + If you enable CONFIG_FAULT_INJECTION_DEBUG_FS the fail_add_disk failure + injection parameters are placed under: + + /sys/kernel/debug/kernfs/fail_kernfs_fop_write_iter/ + - fail_make_request injects disk IO errors on devices permitted by setting @@ -155,6 +168,43 @@ configuration of fault-injection capabilities. default is 'N', setting it to 'Y' will disable failure injections when dealing with private (address space) futexes. +- /sys/kernel/debug/fail_kernfs/sleep_after_wait_ms + + Format: { digit-representing-milliseconds } + + Configure how long to sleep in ms after a kernfs_debug_wait_completion + wait for completion. This completion is currently only used if any of the + waits are enabled under + /sys/kernel/debug/fail_kernfs/config_fail_kernfs_fop_write_iter/ + +- /sys/kernel/debug/fail_kernfs/config_fail_kernfs_fop_write_iter/wait_after_active + + Format: { 'Y' | 'N' } + + Whether or not to issue a wait for completion after the kernfs_get_active() + completes on the kernfs_fop_write_iter() routine. + +- /sys/kernel/debug/fail_kernfs/config_fail_kernfs_fop_write_iter/wait_after_mutex + + Format: { 'Y' | 'N' } + + Whether or not to issue a wait for completion after the struct + kernfs_open_file mutex is taken on the routine kernfs_fop_write_iter(). + +- /sys/kernel/debug/fail_kernfs/config_fail_kernfs_fop_write_iter/wait_at_start + + Format: { 'Y' | 'N' } + + Whether or not to issue a wait for completion after the very beginning of the + routine kernfs_fop_write_iter(). + +- /sys/kernel/debug/fail_kernfs/config_fail_kernfs_fop_write_iter/wait_before_mutex + + Format: { 'Y' | 'N' } + + Whether or not to issue a wait for completion before the struct + kernfs_open_file mutex is taken on the routine kernfs_fop_write_iter(). + - /sys/kernel/debug/fail_sunrpc/ignore-client-disconnect: Format: { 'Y' | 'N' } diff --git a/MAINTAINERS b/MAINTAINERS index 8b458c4dd577..61a89bab1d73 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10469,7 +10469,7 @@ M: Greg Kroah-Hartman M: Tejun Heo S: Supported T: git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git -F: fs/kernfs/ +F: fs/kernfs/* F: include/linux/kernfs.h KEXEC diff --git a/fs/kernfs/Makefile b/fs/kernfs/Makefile index 4ca54ff54c98..79ac7688b108 100644 --- a/fs/kernfs/Makefile +++ b/fs/kernfs/Makefile @@ -4,3 +4,4 @@ # obj-y := mount.o inode.o dir.o file.o symlink.o +obj-$(CONFIG_FAIL_KERNFS_KNOBS) += fault_inject.o diff --git a/fs/kernfs/fault_inject.c b/fs/kernfs/fault_inject.c new file mode 100644 index 000000000000..f887f26646aa --- /dev/null +++ b/fs/kernfs/fault_inject.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include + +#include "kernfs-internal.h" + +static DECLARE_FAULT_ATTR(fail_kernfs_fop_write_iter); +struct kernfs_config_fail kernfs_config_fail; + +#define kernfs_config_fail(when) \ + kernfs_config_fail.kernfs_fop_write_iter_fail.wait_ ## when + +#define kernfs_config_fail(when) \ + kernfs_config_fail.kernfs_fop_write_iter_fail.wait_ ## when + +static int __init setup_fail_kernfs_fop_write_iter(char *str) +{ + return setup_fault_attr(&fail_kernfs_fop_write_iter, str); +} + +__setup("fail_kernfs_fop_write_iter=", setup_fail_kernfs_fop_write_iter); + +struct dentry *kernfs_debugfs_root; +struct dentry *config_fail_kernfs_fop_write_iter; + +static int __init kernfs_init_failure_injection(void) +{ + kernfs_config_fail.sleep_after_wait_ms = 100; + kernfs_debugfs_root = debugfs_create_dir("fail_kernfs", NULL); + + fault_create_debugfs_attr("fail_kernfs_fop_write_iter", + kernfs_debugfs_root, &fail_kernfs_fop_write_iter); + + config_fail_kernfs_fop_write_iter = + debugfs_create_dir("config_fail_kernfs_fop_write_iter", + kernfs_debugfs_root); + + debugfs_create_u32("sleep_after_wait_ms", 0600, + kernfs_debugfs_root, + &kernfs_config_fail.sleep_after_wait_ms); + + debugfs_create_bool("wait_at_start", 0600, + config_fail_kernfs_fop_write_iter, + &kernfs_config_fail(at_start)); + debugfs_create_bool("wait_before_mutex", 0600, + config_fail_kernfs_fop_write_iter, + &kernfs_config_fail(before_mutex)); + debugfs_create_bool("wait_after_mutex", 0600, + config_fail_kernfs_fop_write_iter, + &kernfs_config_fail(after_mutex)); + debugfs_create_bool("wait_after_active", 0600, + config_fail_kernfs_fop_write_iter, + &kernfs_config_fail(after_active)); + return 0; +} +late_initcall(kernfs_init_failure_injection); + +DECLARE_COMPLETION(kernfs_debug_wait_completion); +EXPORT_SYMBOL_NS_GPL(kernfs_debug_wait_completion, KERNFS_DEBUG_PRIVATE); + +static void kernfs_debug_wait(void) +{ + unsigned long timeout; + + timeout = wait_for_completion_timeout(&kernfs_debug_wait_completion, + msecs_to_jiffies(3000)); + if (!timeout) + pr_info("waiting for kernfs_debug_wait_completion timed out\n"); + else + pr_info("received completion with time left on timeout %u ms\n", + jiffies_to_msecs(timeout)); + + /** + * The goal is wait for an event, and *then* once we have + * reached it, the other side will try to do something which + * it thinks will break. So we must give it some time to do + * that. The amount of time is configurable. + */ + msleep(kernfs_config_fail.sleep_after_wait_ms); + pr_info("wait for kernfs_debug_wait_completion ended\n"); +} + +void __kernfs_debug_should_wait_kernfs_fop_write_iter(bool evaluate) +{ + if (!evaluate) + return; + + if (should_fail(&fail_kernfs_fop_write_iter, 0)) + kernfs_debug_wait(); +} diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 60e2a86c535e..860fc8912520 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -259,6 +259,8 @@ static ssize_t kernfs_fop_write_iter(struct kiocb *iocb, struct iov_iter *iter) const struct kernfs_ops *ops; char *buf; + may_wait_kernfs_debug(kernfs_fop_write_iter, at_start); + if (of->atomic_write_len) { if (len > of->atomic_write_len) return -E2BIG; @@ -280,17 +282,24 @@ static ssize_t kernfs_fop_write_iter(struct kiocb *iocb, struct iov_iter *iter) } buf[len] = '\0'; /* guarantee string termination */ + may_wait_kernfs_debug(kernfs_fop_write_iter, before_mutex); + /* * @of->mutex nests outside active ref and is used both to ensure that * the ops aren't called concurrently for the same open file. */ mutex_lock(&of->mutex); + + may_wait_kernfs_debug(kernfs_fop_write_iter, after_mutex); + if (!kernfs_get_active(of->kn)) { mutex_unlock(&of->mutex); len = -ENODEV; goto out_free; } + may_wait_kernfs_debug(kernfs_fop_write_iter, after_active); + ops = kernfs_ops(of->kn); if (ops->write) len = ops->write(of, buf, len, iocb->ki_pos); diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index f9cc912c31e1..278bd935982d 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -18,6 +18,7 @@ #include #include +#include struct kernfs_iattrs { kuid_t ia_uid; @@ -147,4 +148,73 @@ void kernfs_drain_open_files(struct kernfs_node *kn); */ extern const struct inode_operations kernfs_symlink_iops; +/* + * failure-injection.c + */ +#ifdef CONFIG_FAIL_KERNFS_KNOBS + +/** + * struct kernfs_fop_write_iter_fail - how kernfs_fop_write_iter_fail fails + * + * This lets you configure what part of kernfs_fop_write_iter() should behave + * in a specific way to allow userspace to capture possible failures in + * kernfs. The wait knobs are allowed to let you design capture possible + * race conditions which would otherwise be difficult to reproduce. A + * secondary driver would tell kernfs's wait completion when it is done. + * + * The point to the wait completion failure injection tests are to confirm + * that the kernfs active refcount suffice to ensure other objects in other + * layers are also gauranteed to exist, even they are opaque to kernfs. This + * includes kobjects, devices, and other objects built on top of this, like + * the block layer when using sysfs block device attributes. + * + * @wait_at_start: waits for completion from a third party at the start of + * the routine. + * @wait_before_mutex: waits for completion from a third party before we + * are allowed to continue before the of->mutex is held. + * @wait_after_mutex: waits for completion from a third party after we + * have held the of->mutex. + * @wait_after_active: waits for completion from a thid party after we + * have refcounted the struct kernfs_node. + */ +struct kernfs_fop_write_iter_fail { + bool wait_at_start; + bool wait_before_mutex; + bool wait_after_mutex; + bool wait_after_active; +}; + +/** + * struct kernfs_config_fail - kernfs configuration for failure injection + * + * You can kernfs failure injection on boot, and in particular we currently + * only support failures for kernfs_fop_write_iter(). However, we don't + * want to always enable errors on this call when failure injection is enabled + * as this routine is used by many parts of the kernel for proper functionality. + * The compromise we make is we let userspace start enabling which parts it + * wants to fail after boot, if and only if failure injection has been enabled. + * + * @kernfs_fop_write_iter_fail: configuration for how we want to allow + * for failure injection on kernfs_fop_write_iter() + * @sleep_after_wait_ms: how many ms to wait after completion is received. + */ +struct kernfs_config_fail { + struct kernfs_fop_write_iter_fail kernfs_fop_write_iter_fail; + u32 sleep_after_wait_ms; +}; + +extern struct kernfs_config_fail kernfs_config_fail; + +#define __kernfs_config_wait_var(func, when) \ + (kernfs_config_fail.func ##_fail.wait_ ##when) +#define __kernfs_debug_should_wait_func_name(func) __kernfs_debug_should_wait_## func + +#define may_wait_kernfs_debug(func, when) \ + __kernfs_debug_should_wait_func_name(func)(__kernfs_config_wait_var(func, when)) +void __kernfs_debug_should_wait_kernfs_fop_write_iter(bool evaluate); +#else +static inline void kernfs_init_failure_injection(void) {} +#define may_wait_kernfs_debug(func, when) do { } while(0) +#endif + #endif /* __KERNFS_INTERNAL_H */ diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 3ccce6f24548..cd968ee2b503 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -411,6 +411,11 @@ void kernfs_init(void); struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, u64 id); + +#ifdef CONFIG_FAIL_KERNFS_KNOBS +extern struct completion kernfs_debug_wait_completion; +#endif + #else /* CONFIG_KERNFS */ static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ec531b423c0e..04d2c3f53d2a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1902,6 +1902,16 @@ config FAULT_INJECTION_USERCOPY Provides fault-injection capability to inject failures in usercopy functions (copy_from_user(), get_user(), ...). +config FAIL_KERNFS_KNOBS + bool "Fault-injection support in kernfs" + depends on FAULT_INJECTION + help + Provide fault-injection capability for kernfs. This only enables + the error injection functionality. To use it you must configure which + which path you want to trigger on error on using debugfs under + /sys/kernel/debug/kernfs/config_fail_kernfs_fop_write_iter/. By + default all of these are disabled. + config FAIL_MAKE_REQUEST bool "Fault-injection capability for disk IO" depends on FAULT_INJECTION && BLOCK From patchwork Fri Oct 29 18:44:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 12593363 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2AA4BC43219 for ; Fri, 29 Oct 2021 18:45:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AB5C60ED5 for ; Fri, 29 Oct 2021 18:45:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230271AbhJ2Srj (ORCPT ); Fri, 29 Oct 2021 14:47:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229873AbhJ2Srh (ORCPT ); Fri, 29 Oct 2021 14:47:37 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B155C061714; Fri, 29 Oct 2021 11:45:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=toCC9cs8J7FosIh7uJC7Ufw8/yWElGjTPymhmc9QVAM=; b=KikeCKFSSZP70jkPPxMHOTQ5Zf RCM9FcPMprIBXJVs6rTmggSPRPQic7/E6h45P2sX8NNtYNsRvfhQxhLDSKPKHUsYyE7OgSIY5Iea2 NWrf8MknljdCUMEe1fwknjiTIxqj9Azto0U/0wf4RtqFQSPujhgVX+9KeuORXtgRCi4B2JvYwe9zP b7Ro2W9mxCc+S3UWEd3NEA212JOv6721ws5M9FiIGgFb/JtSLvVJTeJdbFZouWY4ozNldQ4Ai9pwK hI/cKiyh368z/oAs5qO4QgwB+ctddUd+x7ylQkDNLjNTGK+xXNJgHAFsbk2SLROMiHe04KDfWt08v iXAMZIng==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgWsA-00Bq0X-Hw; Fri, 29 Oct 2021 18:45:02 +0000 From: Luis Chamberlain To: tj@kernel.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, jeyu@kernel.org, shuah@kernel.org Cc: bvanassche@acm.org, dan.j.williams@intel.com, joe@perches.com, tglx@linutronix.de, mcgrof@kernel.org, keescook@chromium.org, rostedt@goodmis.org, minchan@kernel.org, linux-spdx@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 5/6] test_sysfs: add support to use kernfs failure injection Date: Fri, 29 Oct 2021 11:44:59 -0700 Message-Id: <20211029184500.2821444-6-mcgrof@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211029184500.2821444-1-mcgrof@kernel.org> References: <20211029184500.2821444-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This extends test_sysfs with support for using the failure injection wait completion and knobs to force a few race conditions which demonstrates that kernfs active reference protection is sufficient for kobject / device protection at higher layers. This adds 4 new tests which tries to remove the device attribute store operation in 4 different situations: 1) at the start of kernfs_kernfs_fop_write_iter() 2) before the of->mutex is held in kernfs_kernfs_fop_write_iter() 3) after the of->mutex is held in kernfs_kernfs_fop_write_iter() 4) after the kernfs node active reference is taken with kernfs_get_active() A write can fail or succeed before the kernfs node active reference is obtained with kernfs_get_active(), and the reason is that the del_gendisk() may happen before the write or after the write is triggered. However, regardless of the delayed used, all writes are gauranteed to succeed after kernfs_get_active(), and so del_gendisk() must wait for any pending writes to complete. The fact that you cannot remove the kernfs entry while the kenfs entry is active also implies that a module that created the respective sysfs / kernfs entry *cannot* be removed during a sysfs operation. Test number 32 provides us with proof of this. If it were not true test #32 should crash. No null dereferences are reproduced, even though this has been observed in some complex testing cases [0]. If this issue really exists we should have enough tools on the sysfs_test toolbox now to try to reproduce this easily without having to poke around other drivers. It very likley was the case that the issue reported [0] was possibly a side issue after the first bug which was zram specific. This is why it is important to isolate the issue and try to reproduce it in a generic form using the test_sysfs driver. [0] https://lkml.kernel.org/r/20210623215007.862787-1-mcgrof@kernel.org Signed-off-by: Luis Chamberlain --- lib/Kconfig.debug | 1 + lib/test_sysfs.c | 19 +++ tools/testing/selftests/sysfs/config | 3 + tools/testing/selftests/sysfs/sysfs.sh | 214 +++++++++++++++++++++++++ 4 files changed, 237 insertions(+) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 04d2c3f53d2a..ab3052277f23 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2359,6 +2359,7 @@ config TEST_SYSFS depends on SYSFS depends on NET depends on BLOCK + depends on FAIL_KERNFS_KNOBS help This builds the "test_sysfs" module. This driver enables to test the sysfs file system safely without affecting production knobs which diff --git a/lib/test_sysfs.c b/lib/test_sysfs.c index 2a6ec072da60..6918fddb1aed 100644 --- a/lib/test_sysfs.c +++ b/lib/test_sysfs.c @@ -25,6 +25,9 @@ #include #include #include +#include + +MODULE_IMPORT_NS(KERNFS_DEBUG_PRIVATE); static bool enable_lock; module_param(enable_lock, bool_enable_only, 0644); @@ -69,6 +72,11 @@ static bool enable_verbose_rmmod; module_param(enable_verbose_rmmod, bool_enable_only, 0644); MODULE_PARM_DESC(enable_verbose_rmmod, "enable verbose print messages on rmmod"); +static bool enable_completion_on_rmmod; +module_param(enable_completion_on_rmmod, bool_enable_only, 0644); +MODULE_PARM_DESC(enable_completion_on_rmmod, + "enable sending a kernfs completion on rmmod"); + static int sysfs_test_major; /** @@ -251,6 +259,8 @@ static ssize_t config_show(struct device *dev, enable_debugfs ? "true" : "false"); len += sysfs_emit_at(buf, len, "enable_verbose_writes:\t%s\n", enable_verbose_writes ? "true" : "false"); + len += sysfs_emit_at(buf, len, "enable_completion_on_rmmod:\t%s\n", + enable_completion_on_rmmod ? "true" : "false"); test_dev_config_unlock(test_dev); @@ -877,10 +887,19 @@ static int __init test_sysfs_init(void) } module_init(test_sysfs_init); +/* The goal is to race our device removal with a pending kernfs -> store call */ +static void test_sysfs_kernfs_send_completion_rmmod(void) +{ + if (!enable_completion_on_rmmod) + return; + complete(&kernfs_debug_wait_completion); +} + static void __exit test_sysfs_exit(void) { if (enable_debugfs) debugfs_remove(debugfs_dir); + test_sysfs_kernfs_send_completion_rmmod(); if (delay_rmmod_ms) msleep(delay_rmmod_ms); unregister_test_dev_sysfs(first_test_dev); diff --git a/tools/testing/selftests/sysfs/config b/tools/testing/selftests/sysfs/config index 9196f452ecd5..2876a229f95b 100644 --- a/tools/testing/selftests/sysfs/config +++ b/tools/testing/selftests/sysfs/config @@ -1,2 +1,5 @@ CONFIG_SYSFS=m CONFIG_TEST_SYSFS=m +CONFIG_FAULT_INJECTION=y +CONFIG_FAULT_INJECTION_DEBUG_FS=y +CONFIG_FAIL_KERNFS_KNOBS=y diff --git a/tools/testing/selftests/sysfs/sysfs.sh b/tools/testing/selftests/sysfs/sysfs.sh index 802651d78427..84093ee653c6 100755 --- a/tools/testing/selftests/sysfs/sysfs.sh +++ b/tools/testing/selftests/sysfs/sysfs.sh @@ -51,6 +51,10 @@ ALL_TESTS="$ALL_TESTS 0025:1:1:test_dev_y:block" ALL_TESTS="$ALL_TESTS 0026:1:1:test_dev_y:block" ALL_TESTS="$ALL_TESTS 0027:1:0:test_dev_x:block" # deadlock test ALL_TESTS="$ALL_TESTS 0028:1:0:test_dev_x:block" # deadlock test with rntl_lock +ALL_TESTS="$ALL_TESTS 0029:1:1:test_dev_x:block" # kernfs race removal of store +ALL_TESTS="$ALL_TESTS 0030:1:1:test_dev_x:block" # kernfs race removal before mutex +ALL_TESTS="$ALL_TESTS 0031:1:1:test_dev_x:block" # kernfs race removal after mutex +ALL_TESTS="$ALL_TESTS 0032:1:1:test_dev_x:block" # kernfs race removal after active allow_user_defaults() { @@ -81,6 +85,9 @@ allow_user_defaults() if [ -z $SYSFS_DEBUGFS_DIR ]; then SYSFS_DEBUGFS_DIR="/sys/kernel/debug/test_sysfs" fi + if [ -z $KERNFS_DEBUGFS_DIR ]; then + KERNFS_DEBUGFS_DIR="/sys/kernel/debug/fail_kernfs" + fi if [ -z $PAGE_SIZE ]; then PAGE_SIZE=$(getconf PAGESIZE) fi @@ -156,6 +163,14 @@ modprobe_reset_enable_rtnl_lock_on_rmmod() unset FIRST_MODPROBE_ARGS } +modprobe_reset_enable_completion() +{ + FIRST_MODPROBE_ARGS="enable_completion_on_rmmod=1 enable_verbose_writes=1" + FIRST_MODPROBE_ARGS="$FIRST_MODPROBE_ARGS enable_verbose_rmmod=1 delay_rmmod_ms=0" + modprobe_reset + unset FIRST_MODPROBE_ARGS +} + load_req_mod() { modprobe_reset @@ -186,6 +201,63 @@ debugfs_reset_first_test_dev_ignore_errors() echo -n "1" >"$SYSFS_DEBUGFS_DIR"/reset_first_test_dev } +debugfs_kernfs_kernfs_fop_write_iter_exists() +{ + KNOB_DIR="${KERNFS_DEBUGFS_DIR}/config_fail_kernfs_fop_write_iter" + if [[ ! -d $KNOB_DIR ]]; then + echo "kernfs debugfs does not exist $KNOB_DIR" + return 0; + fi + KNOB_DEBUGFS="${KERNFS_DEBUGFS_DIR}/fail_kernfs_fop_write_iter" + if [[ ! -d $KNOB_DEBUGFS ]]; then + echo -n "kernfs debugfs for coniguring fail_kernfs_fop_write_iter " + echo "does not exist $KNOB_DIR" + return 0; + fi + return 1 +} + +debugfs_kernfs_kernfs_fop_write_iter_set_fail_once() +{ + KNOB_DEBUGFS="${KERNFS_DEBUGFS_DIR}/fail_kernfs_fop_write_iter" + echo 1 > $KNOB_DEBUGFS/interval + echo 100 > $KNOB_DEBUGFS/probability + echo 0 > $KNOB_DEBUGFS/space + # Disable verbose messages on the kernel ring buffer which may + # confuse developers with a kernel panic. + echo 0 > $KNOB_DEBUGFS/verbose + + # Fail only once + echo 1 > $KNOB_DEBUGFS/times +} + +debugfs_kernfs_kernfs_fop_write_iter_set_fail_never() +{ + KNOB_DEBUGFS="${KERNFS_DEBUGFS_DIR}/fail_kernfs_fop_write_iter" + echo 0 > $KNOB_DEBUGFS/times +} + +debugfs_kernfs_set_wait_ms() +{ + SLEEP_AFTER_WAIT_MS="${KERNFS_DEBUGFS_DIR}/sleep_after_wait_ms" + echo $1 > $SLEEP_AFTER_WAIT_MS +} + +debugfs_kernfs_disable_wait_kernfs_fop_write_iter() +{ + ENABLE_WAIT_KNOB="${KERNFS_DEBUGFS_DIR}/config_fail_kernfs_fop_write_iter/wait_" + for KNOB in ${ENABLE_WAIT_KNOB}*; do + echo 0 > $KNOB + done +} + +debugfs_kernfs_enable_wait_kernfs_fop_write_iter() +{ + ENABLE_WAIT_KNOB="${KERNFS_DEBUGFS_DIR}/config_fail_kernfs_fop_write_iter/wait_$1" + echo -n "1" > $ENABLE_WAIT_KNOB + return $? +} + set_orig() { if [[ ! -z $TARGET ]] && [[ ! -z $ORIG ]]; then @@ -961,6 +1033,144 @@ sysfs_test_0028() fi } +sysfs_race_kernfs_kernfs_fop_write_iter() +{ + TARGET="${DIR}/$(get_test_target $1)" + WAIT_AT=$2 + EXPECT_WRITE_RETURNS=$3 + MSDELAY=$4 + + modprobe_reset_enable_completion + ORIG=$(cat "${TARGET}") + TEST_STR=$(( $ORIG + 1 )) + + echo -n "Test racing removal of sysfs store op with kernfs $WAIT_AT ... " + + if debugfs_kernfs_kernfs_fop_write_iter_exists; then + echo -n "skipping test as CONFIG_FAIL_KERNFS_KNOBS " + echo " or CONFIG_FAULT_INJECTION_DEBUG_FS is disabled" + return $ksft_skip + fi + + # Allow for failing the kernfs_kernfs_fop_write_iter call once, + # we'll provide exact context shortly afterwards. + debugfs_kernfs_kernfs_fop_write_iter_set_fail_once + + # First disable all waits + debugfs_kernfs_disable_wait_kernfs_fop_write_iter + + # Enable a wait_for_completion(&kernfs_debug_wait_completion) at the + # specified location inside the kernfs_fop_write_iter() routine + debugfs_kernfs_enable_wait_kernfs_fop_write_iter $WAIT_AT + + # Configure kernfs so that after its wait_for_completion() it + # will msleep() this amount of time and schedule(). We figure this + # will be sufficient time to allow for our module removal to complete. + debugfs_kernfs_set_wait_ms $MSDELAY + + # Now we trigger a kernfs write op, which will run kernfs_fop_write_iter, + # but will wait until our driver sends a respective completion + set_test_ignore_errors & + write_pid=$! + + # At this point kernfs_fop_write_iter() hasn't run our op, its + # waiting for our completion at the specified time $WAIT_AT. + # We now remove our module which will send a + # complete(&kernfs_debug_wait_completion) right before we deregister + # our device and the sysfs device attributes are removed. + # + # After the completion is sent, the test_sysfs driver races with + # kernfs to do the device deregistration with the kernfs msleep + # and schedule(). This should mean we've forced trying to remove the + # module prior to allowing kernfs to run our store operation. If the + # race did happen we'll panic with a null dereference on the store op. + # + # If no race happens we should see no write operation triggered. + modprobe -r $TEST_DRIVER > /dev/null 2>&1 + + debugfs_kernfs_kernfs_fop_write_iter_set_fail_never + + wait $write_pid + + check_dmesg + if [[ $? -ne 0 ]]; then + echo "FAIL" >&2 + exit 1 + fi + + # In cases where a write *can* fail or succeed, we don't care + # about the return code of the write, we just care we don't crash + # the kernel. + if [[ "$EXPECT_WRITE_RETURNS" == "2" ]]; then + echo "ok" + return + fi + + if [[ $? -eq $EXPECT_WRITE_RETURNS ]]; then + echo "ok" + else + echo "FAIL" >&2 + fi +} + +# The test cases 0029-0032 race writes issued to sysfs files exposed by a +# disk against del_gendisk() which removes these sysfs files. Each test case +# forces the race to happen at different points in time where the kernfs is +# processing a write, before the sysfs op gets called. +# +# The writes races against different parts of the kernfs_fop_write_iter(). +# A completion is sent by the test_sysfs driver on driver removal before +# del_gendisk() is called so to *start* the race. The races vary by time, +# specified in milliseconds. +# +# So for example test case 0029 will force the function kernfs_fop_write_iter() +# to wait for completion *at the start* of that function. The completion is +# issued by the test_sysfs driver on driver removal right before del_gendisk() +# is called. However test_sysfs will also wait a configurable amount of +# milliseconds before having del_gendisk() run. A long delay should ensure the +# write completes. +# +# Test case 0030 will do the same but before mutex_lock(&of->mutex) is called +# on kernfs_fop_write_iter(). And so on. Writes are only expected to *always* +# succeed once kernfs_get_active() is called successfully. Before that a write +# could succeed or fail, it will depend on what gets preempted / scheduled, and +# so the only thing we can be sure of is we should not be crashing the kernel. +# Before kernfs_get_active(), if an excessively long delay is used, then +# del_gendisk() is expected to be delayed and so writes should work. +sysfs_test_0029() +{ + for delay in 0 2 4 8 16 32 64 128 246 512 1024; do + echo "Delay-after-completion before del_gendisk(): $delay ms" + sysfs_race_kernfs_kernfs_fop_write_iter 0029 at_start 2 $delay + done +} + +sysfs_test_0030() +{ + for delay in 0 2 4 8 16 32 64 128 246 512 1024; do + echo "Delay-after-completion before del_gendisk(): $delay ms" + sysfs_race_kernfs_kernfs_fop_write_iter 0030 before_mutex 2 $delay + done +} + +sysfs_test_0031() +{ + for delay in 0 2 4 8 16 32 64 128 246 512 1024; do + echo "Delay-after-completion before del_gendisk(): $delay ms" + sysfs_race_kernfs_kernfs_fop_write_iter 0031 after_mutex 2 $delay + done +} + +# A write only guaranteed to succeed *iff* a module removal happens *after* +# the kernfs active reference is obtained with kernfs_get_active(). +sysfs_test_0032() +{ + for delay in 0 2 4 8 16 32 64 128 246 512 1024; do + echo "Delay-after-completion before del_gendisk(): $delay ms" + sysfs_race_kernfs_kernfs_fop_write_iter 0032 after_active 0 $delay + done +} + test_gen_desc() { echo -n "$1 x $(get_test_count $1)" @@ -1002,6 +1212,10 @@ list_tests() echo "$(test_gen_desc 0026) - block test writing y larger delay and resetting device" echo "$(test_gen_desc 0027) - test rmmod deadlock while writing x ... " echo "$(test_gen_desc 0028) - test rmmod deadlock using rtnl_lock while writing x ..." + echo "$(test_gen_desc 0029) - racing removal of store op with kernfs at start" + echo "$(test_gen_desc 0030) - racing removal of store op with kernfs before mutex" + echo "$(test_gen_desc 0031) - racing removal of store op with kernfs after mutex" + echo "$(test_gen_desc 0032) - racing removal of store op with kernfs after active" } usage() From patchwork Fri Oct 29 18:45:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 12593371 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61404C433FE for ; Fri, 29 Oct 2021 18:45:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C50B60F4B for ; Fri, 29 Oct 2021 18:45:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230215AbhJ2Sri (ORCPT ); Fri, 29 Oct 2021 14:47:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229979AbhJ2Sri (ORCPT ); Fri, 29 Oct 2021 14:47:38 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21092C061570; Fri, 29 Oct 2021 11:45:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=CinqUVkMzd6CB9z1z2X8npZ2uAGAUzQCiqL6GyuyIm0=; b=a72lUGBYbV0SGTwe2YBTsJbi+e FQQucBlD2VvlZG8WToyNmZLd7BPi0q+zFEQmGjZF0KcNzUwqLtVY8NCT/33gA/I8HmN9GfTZKrWrv jJwxD33ofoJQLLr7G9jhfF6g9QQW17Vi/72ySUvvOWZ7bpm3jz8jKbdL4N6XLVCQ/CHP0sawLaiSt iKPm+rsQaLJm1YIc9/BaCtbYBEc4N2eHOxqP3Q9bausP84a4f69c+lIleXtk+RnVgvpbdoLxldeb9 A5Lfa5R5JuRRM5qljbCNxcFrRh9no+AM+LvSpVVppgzmjhliWdZyv7Gg7Ux8gmqPdXdRcJEjhWDEk OvW4Y17g==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgWsA-00Bq0Z-Kp; Fri, 29 Oct 2021 18:45:02 +0000 From: Luis Chamberlain To: tj@kernel.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, jeyu@kernel.org, shuah@kernel.org Cc: bvanassche@acm.org, dan.j.williams@intel.com, joe@perches.com, tglx@linutronix.de, mcgrof@kernel.org, keescook@chromium.org, rostedt@goodmis.org, minchan@kernel.org, linux-spdx@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 6/6] kernel/module: add documentation for try_module_get() Date: Fri, 29 Oct 2021 11:45:00 -0700 Message-Id: <20211029184500.2821444-7-mcgrof@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211029184500.2821444-1-mcgrof@kernel.org> References: <20211029184500.2821444-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org There is quite a bit of tribal knowledge around proper use of try_module_get() and that it must be used only in a context which can ensure the module won't be gone during the operation. Document this little bit of tribal knowledge. I'm extending this tribal knowledge with new developments which it seems some folks do not yet believe to be true: we can be sure a module will exist during the lifetime of a sysfs file operation. For proof, refer to test_sysfs test #32: ./tools/testing/selftests/sysfs/sysfs.sh -t 0032 Without this being true, the write would fail or worse, a crash would happen, in this test. It does not. Signed-off-by: Luis Chamberlain --- include/linux/module.h | 37 +++++++++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index c9f1200b2312..35c98e4196cb 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -609,10 +609,43 @@ void symbol_put_addr(void *addr); to handle the error case (which only happens with rmmod --wait). */ extern void __module_get(struct module *module); -/* This is the Right Way to get a module: if it fails, it's being removed, - * so pretend it's not there. */ +/** + * try_module_get() - Take module refcount unless module is being removed + * @module: the module we should check for + * + * This can be used to try to bump the reference count of a module, so to + * prevent module removal. The reference count of a module is not allowed + * to be incremented if the module is already being removed. + * + * Care must be taken to ensure the module cannot be removed during the call to + * try_module_get() because otherwise use of this routine could crash the kernel + * when racing to remove a module. Proper care can be taken by having another + * entity other than the module itself increment the module reference count, + * or through some other means which guarantees the module could not be removed + * during an operation. An example of this later case is using try_module_get() + * in a sysfs file which the module created. The sysfs store / read file + * operations are gauranteed to exist through the use of kernfs's active + * reference (see kernfs_active()). If a sysfs file operation is being run, + * the module which created it must still exist as the module is in charge of + * removing the same sysfs file being used. A sysfs / kernfs file removal + * cannot happen unless the same file does not have an active reference. + * + * One of the real values to try_module_get() is the module_is_live() check + * which ensures this the caller of try_module_get() can yield to userspace + * module removal requests and fail whatever it was about to process. + * + * Returns true if the reference count was successfully incremented. + */ extern bool try_module_get(struct module *module); +/** + * module_put() - release a reference count to a module + * @module: the module we should release a reference count for + * + * If you successfully bump a reference count to a module with try_module_get(), + * when you are finished you must call module_put() to release that reference + * count. + */ extern void module_put(struct module *module); #else /*!CONFIG_MODULE_UNLOAD*/