From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 597BAC43334 for ; Fri, 8 Jul 2022 20:31:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240089AbiGHUbd (ORCPT ); Fri, 8 Jul 2022 16:31:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240087AbiGHUbY (ORCPT ); Fri, 8 Jul 2022 16:31:24 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 474959B1AC for ; Fri, 8 Jul 2022 13:31:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D5A3CB82935 for ; Fri, 8 Jul 2022 20:31:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86386C341C7; Fri, 8 Jul 2022 20:31:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1657312279; bh=eELo1u1MFPdi2VbtFUVzjNPih7CYRaTj1nsaRDLxR2I=; h=Date:To:From:Subject:From; b=2C0xxsbSMLbUknPbcwH8faEhcOYALPVf4oeEcpFv0PUr0G4+/pBW1QOSvn2B8ILQH NubaGgopQJlcgu996IHksKAq/jTz24RGUTBg9itX2d2Tc6+EJ7rMyFOdDnrgWGynOj MQPx7ZS710AkZMBe/jcRkh9/IMEaE2hXphg3I5hU= Date: Fri, 08 Jul 2022 13:31:18 -0700 To: mm-commits@vger.kernel.org, sre@kernel.org, skhan@linuxfoundation.org, ndesaulniers@google.com, nathan@kernel.org, michal.lkml@markovi.net, mcgrof@kernel.org, masahiroy@kernel.org, lucas.demarchi@intel.com, keescook@chromium.org, john.ogness@linutronix.de, jani.nikula@linux.intel.com, gregkh@linuxfoundation.org, gpiccoli@igalia.com, dlatypov@google.com, corbet@lwn.net, brendanhiggins@google.com, atomlin@redhat.com, andriy.shevchenko@linux.intel.com, davidgow@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + selftest-taint-kernel-when-test-module-loaded.patch added to mm-nonmm-unstable branch Message-Id: <20220708203119.86386C341C7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: selftest: taint kernel when test module loaded has been added to the -mm mm-nonmm-unstable branch. Its filename is selftest-taint-kernel-when-test-module-loaded.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftest-taint-kernel-when-test-module-loaded.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: David Gow Subject: selftest: taint kernel when test module loaded Date: Fri, 8 Jul 2022 12:48:47 +0800 Make any kselftest test module (using the kselftest_module framework) taint the kernel with TAINT_TEST on module load. Also mark the module as a test module using MODULE_INFO(test, "Y") so that other tools can tell this is a test module. We can't rely solely on this, though, as these test modules are also often built-in. Finally, update the kselftest documentation to mention that the kernel should be tainted, and how to do so manually (as below). Note that several selftests use kernel modules which are not based on the kselftest_module framework, and so will not automatically taint the kernel. This can be done in two ways: - Moving the module to the tools/testing directory. All modules under this directory will taint the kernel. - Adding the 'test' module property with: MODULE_INFO(test, "Y") Similarly, selftests which do not load modules into the kernel generally should not taint the kernel (or possibly should only do so on failure), as it's assumed that testing from user-space should be safe. Regardless, they can write to /proc/sys/kernel/tainted if required. Link: https://lkml.kernel.org/r/20220708044847.531566-4-davidgow@google.com Signed-off-by: David Gow Reviewed-by: Luis Chamberlain Acked-by: Brendan Higgins Cc: Aaron Tomlin Cc: Andy Shevchenko Cc: Daniel Latypov Cc: Greg Kroah-Hartman Cc: Guilherme G. Piccoli Cc: Jani Nikula Cc: John Ogness Cc: Jonathan Corbet Cc: Kees Cook Cc: Lucas De Marchi Cc: Masahiro Yamada Cc: Michal Marek Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Sebastian Reichel Cc: Shuah Khan Signed-off-by: Andrew Morton --- Documentation/dev-tools/kselftest.rst | 9 +++++++++ tools/testing/selftests/kselftest_module.h | 4 ++++ 2 files changed, 13 insertions(+) --- a/Documentation/dev-tools/kselftest.rst~selftest-taint-kernel-when-test-module-loaded +++ a/Documentation/dev-tools/kselftest.rst @@ -250,6 +250,14 @@ assist writing kernel modules that are f - ``tools/testing/selftests/kselftest_module.h`` - ``tools/testing/selftests/kselftest/module.sh`` +Note that test modules should taint the kernel with TAINT_TEST. This will +happen automatically for modules which are in the ``tools/testing/`` +directory, or for modules which use the ``kselftest_module.h`` header above. +Otherwise, you'll need to add ``MODULE_INFO(test, "Y")`` to your module +source. selftests which do not load modules typically should not taint the +kernel, but in cases where a non-test module is loaded, TEST_TAINT can be +applied from userspace by writing to ``/proc/sys/kernel/tainted``. + How to use ---------- @@ -308,6 +316,7 @@ A bare bones test module might look like KSTM_MODULE_LOADERS(test_foo); MODULE_AUTHOR("John Developer "); MODULE_LICENSE("GPL"); + MODULE_INFO(test, "Y"); Example test script ------------------- --- a/tools/testing/selftests/kselftest_module.h~selftest-taint-kernel-when-test-module-loaded +++ a/tools/testing/selftests/kselftest_module.h @@ -3,6 +3,7 @@ #define __KSELFTEST_MODULE_H #include +#include /* * Test framework for writing test modules to be loaded by kselftest. @@ -41,6 +42,7 @@ static inline int kstm_report(unsigned i static int __init __module##_init(void) \ { \ pr_info("loaded.\n"); \ + add_taint(TAINT_TEST, LOCKDEP_STILL_OK); \ selftest(); \ return kstm_report(total_tests, failed_tests, skipped_tests); \ } \ @@ -51,4 +53,6 @@ static void __exit __module##_exit(void) module_init(__module##_init); \ module_exit(__module##_exit) +MODULE_INFO(test, "Y"); + #endif /* __KSELFTEST_MODULE_H */ _ Patches currently in -mm which might be from davidgow@google.com are panic-taint-kernel-if-tests-are-run.patch module-panic-taint-the-kernel-when-selftest-modules-load.patch kunit-taint-the-kernel-when-kunit-tests-are-run.patch selftest-taint-kernel-when-test-module-loaded.patch