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Harding" X-Patchwork-Id: 10841827 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BB1671575 for ; Wed, 6 Mar 2019 21:44:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AC9AD2EDDF for ; Wed, 6 Mar 2019 21:44:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AAE692EE31; Wed, 6 Mar 2019 21:44:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 70DD32EE2D for ; Wed, 6 Mar 2019 21:44:05 +0000 (UTC) Received: (qmail 9697 invoked by uid 550); 6 Mar 2019 21:43:49 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 9600 invoked from network); 6 Mar 2019 21:43:48 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm2; bh=7RCtABdbAJh7ag4bDRO1qAGVOkgFNMZVsbJDyJA5Cn0=; b=AO3NbWHK 6lDne96gU9QFipRPT9pVAckg5u8uzngqMzretn9cYKTOc35zO/tJZgccpMNy2Yj0 Yh7zP3WAvjVigTki6u8prDUCpVt8tbOY1gv587c4xJqmlemsrU9xOYN16qQ8Z10M NVK8FSG8p24a3xDavjaA4p9Mms52yjff3LcH0gBKJ7O334lz8nNk9iP3b1fcGbRx d7OoUh17urkVDfBEyjvfneSlm+aZ0mewHfw+mun83gx6TrKVkgA5poaLGmpEJDd0 GgRqYgJsP5Dwmc3coDQWYvV6uebVZ3ENMaW9jXZbobRogbLem4cgkH+j8OMR2zX7 dTnstgHEaZAIqw== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedutddrfeeigdekjecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkofgjfhgggfestdekredtredttdenucfhrhhomhepfdfvohgsihhn ucevrdcujfgrrhguihhnghdfuceothhosghinheskhgvrhhnvghlrdhorhhgqeenucfkph epuddvgedrudeiledrhedrudehkeenucfrrghrrghmpehmrghilhhfrhhomhepthhosghi nheskhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrhfuihiivgepfe X-ME-Proxy: From: "Tobin C. Harding" To: Kees Cook , Shuah Khan Cc: "Tobin C. Harding" , Jann Horn , Andy Shevchenko , Randy Dunlap , Rasmus Villemoes , Stephen Rothwell , Andy Lutomirski , Daniel Micay , Arnd Bergmann , Miguel Ojeda , "Gustavo A. R. Silva" , Greg Kroah-Hartman , Alexander Shishkin , kernel-hardening@lists.openwall.com, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 4/7] kselftest: Add test module framework header Date: Thu, 7 Mar 2019 08:42:23 +1100 Message-Id: <20190306214226.14598-5-tobin@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190306214226.14598-1-tobin@kernel.org> References: <20190306214226.14598-1-tobin@kernel.org> MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP kselftest runs as a userspace process. Sometimes we need to test things from kernel space. One way of doing this is by creating a test module. Currently doing so requires developers to write a bunch of boiler plate in the module if kselftest is to be used to run the tests. This means we currently have a load of duplicate code to achieve these ends. If we have a uniform method for implementing test modules then we can reduce code duplication, ensure uniformity in the test framework, ease code maintenance, and reduce the work required to create tests. This all helps to encourage developers to write and run tests. Add a C header file that can be included in test modules. This provides a single point for common test functions/macros. Implement a few macros that make up the start of the test framework. Add documentation for new kselftest header and script to kselftest documentation. Signed-off-by: Tobin C. Harding Acked-by: Kees Cook --- Documentation/dev-tools/kselftest.rst | 108 ++++++++++++++++++++- tools/testing/selftests/kselftest_module.h | 48 +++++++++ 2 files changed, 154 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/kselftest_module.h diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst index 7756f7a7c23b..fb7790d47147 100644 --- a/Documentation/dev-tools/kselftest.rst +++ b/Documentation/dev-tools/kselftest.rst @@ -14,6 +14,10 @@ in safe mode with a limited scope. In limited mode, cpu-hotplug test is run on a single cpu as opposed to all hotplug capable cpus, and memory hotplug test is run on 2% of hotplug capable memory instead of 10%. +kselftest runs as a userspace process. Tests that can be written/run in +userspace may wish to use the `Test Harness`_. Tests that need to be +run in kernel space may wish to use a `Test Module`_. + Running the selftests (hotplug tests are run in limited mode) ============================================================= @@ -161,11 +165,111 @@ Contributing new tests (details) e.g: tools/testing/selftests/android/config +Test Module +=========== + +Kselftest tests the kernel from userspace. Sometimes things need +testing from within the kernel, one method of doing this is to create a +test module. We can tie the module into the kselftest framework by +using a shell script test runner. ``kselftest_module.sh`` is designed +to facilitate this process. There is also a header file provided to +assist writing kernel modules that are for use with kselftest: + +- ``tools/testing/kselftest/kselftest_module.h`` +- ``tools/testing/kselftest/kselftest_module.sh`` + +How to use +---------- + +Here we show the typical steps to create a test module and tie it into +kselftest. We use kselftests for lib/ as an example. + +1. Create the test module + +2. Create the test script that will run (load/unload) the module + e.g. ``tools/testing/selftests/lib/printf.sh`` + +3. Add line to config file e.g. ``tools/testing/selftests/lib/config`` + +4. Add test script to makefile e.g. ``tools/testing/selftests/lib/Makefile`` + +5. Verify it works: + +.. code-block:: sh + + # Assumes you have booted a fresh build of this kernel tree + cd /path/to/linux/tree + make kselftest-merge + make modules + sudo make modules_install + make TARGETS=lib kselftest + +Example Module +-------------- + +A bare bones test module might look like this: + +.. code-block:: c + + // SPDX-License-Identifier: GPL-2.0+ + + #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + + #include "../tools/testing/selftests/kselftest_module.h" + + KSTM_MODULE_GLOBALS(); + + /* + * Kernel module for testing the foobinator + */ + + static int __init test_function() + { + ... + } + + static void __init selftest(void) + { + KSTM_CHECK_ZERO(do_test_case("", 0)); + } + + KSTM_MODULE_LOADERS(test_foo); + MODULE_AUTHOR("John Developer "); + MODULE_LICENSE("GPL"); + +Example test script +------------------- + +.. code-block:: sh + + #!/bin/bash + # SPDX-License-Identifier: GPL-2.0+ + + module_name="test_foo" # Module name (without the .ko). + description="foo" # Output prefix. + + # + # Shouldn't need to edit anything below here. + # + + file="kselftest_module.sh" + path="../$file" + if [[ ! $KBUILD_SRC == "" ]]; then + path="${KBUILD_SRC}/tools/testing/selftests/$file" + fi + + $path $module_name $description + + Test Harness ============ -The kselftest_harness.h file contains useful helpers to build tests. The tests -from tools/testing/selftests/seccomp/seccomp_bpf.c can be used as example. +The kselftest_harness.h file contains useful helpers to build tests. The +test harness is for userspace testing, for kernel space testing see `Test +Module`_ above. + +The tests from tools/testing/selftests/seccomp/seccomp_bpf.c can be used as +example. Example ------- diff --git a/tools/testing/selftests/kselftest_module.h b/tools/testing/selftests/kselftest_module.h new file mode 100644 index 000000000000..e8eafaf0941a --- /dev/null +++ b/tools/testing/selftests/kselftest_module.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +#ifndef __KSELFTEST_MODULE_H +#define __KSELFTEST_MODULE_H + +#include + +/* + * Test framework for writing test modules to be loaded by kselftest. + * See Documentation/dev-tools/kselftest.rst for an example test module. + */ + +#define KSTM_MODULE_GLOBALS() \ +static unsigned int total_tests __initdata; \ +static unsigned int failed_tests __initdata + +#define KSTM_CHECK_ZERO(x) do { \ + total_tests++; \ + if (x) { \ + pr_warn("TC failed at %s:%d\n", __func__, __LINE__); \ + failed_tests++; \ + } \ +} while (0) + +static inline int kstm_report(unsigned int total_tests, unsigned int failed_tests) +{ + if (failed_tests == 0) + pr_info("all %u tests passed\n", total_tests); + else + pr_warn("failed %u out of %u tests\n", failed_tests, total_tests); + + return failed_tests ? -EINVAL : 0; +} + +#define KSTM_MODULE_LOADERS(__module) \ +static int __init __module##_init(void) \ +{ \ + pr_info("loaded.\n"); \ + selftest(); \ + return kstm_report(total_tests, failed_tests); \ +} \ +static void __exit __module##_exit(void) \ +{ \ + pr_info("unloaded.\n"); \ +} \ +module_init(__module##_init); \ +module_exit(__module##_exit) + +#endif /* __KSELFTEST_MODULE_H */