From patchwork Thu Sep 10 07:03:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gow X-Patchwork-Id: 11766797 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AEE5D14F6 for ; Thu, 10 Sep 2020 07:06:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9267F207EA for ; Thu, 10 Sep 2020 07:06:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="AvAqHkXs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730178AbgIJHGH (ORCPT ); Thu, 10 Sep 2020 03:06:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730312AbgIJHDu (ORCPT ); Thu, 10 Sep 2020 03:03:50 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA656C06179B for ; Thu, 10 Sep 2020 00:03:49 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id c78so4594306ybf.6 for ; Thu, 10 Sep 2020 00:03:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=+BKi9csz5osX4KTPzoBomTKB3kjtuT5jT2WVtCJDrmk=; b=AvAqHkXsv7qMuQKnTVg1OfhNw92YOEKDUQ7/oDfMNhxYufaVT9M8mkKJp2N5Fj2Tgw oqdZwnrwHxAut0Byfzq2Ya63bK6G2dsJmJtwEfAZ301TjaRgBAr6TPDsQ/uzm+3mhP7P XV4sDg/LLGvTVF4BCNaXX8Nq6LE7hjr1OPSk2ajZDLAQbLM4egPru0wBU8aAfQRwFzcy pQXV7loKshX9qy1HUlWTHGRQyNaNfGcS2t+v9WIWgsJP2w6PJcE8aPUcN8HNM7VpALDN W1PCqh10Ai/vL6T0U4gYWetWiUCRF6nKHUV/nPswQxa9eVPSGBTckrANpPoPdb+CWQAW XSiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=+BKi9csz5osX4KTPzoBomTKB3kjtuT5jT2WVtCJDrmk=; b=C4wGzLNexowQ/zoREDn/goG2BWCz3sYNhKJq/kMYfIgOXjxW+QGvPsvWjuFliqEzxL t6okXKgQneKtkiqGpaFMki2Pct2CJoD5hXduQaOsVMhBrpKyPAcR2m1frYfu3SO/Znxd 6eEeqOa6lGxtpsMPSzWkFWqu2tIxrJYYnyGRQQ67/svARC1hQIIUhhoUjm85X8Va8BCh 9AYehbWSdKnnN+9Jfyr4ZAf0EcDr4O7A5es2F99aoixhxmlQYAtgPr0o6T/NOz5GRAOh NqsOvk19A2D+0hjXuSi3u7oUGtZw8eo+GiVrFiwzBFSBZMT4ut11wgohbiHCUBjlO1/t rV/g== X-Gm-Message-State: AOAM532h1TYATXwhutaPxizFG8P8LrWGMX9nA8V/2HrlaM3DdoCuQwFN zuJIiFvk8IciBdXiVicajfcM3u1IY51UFQ== X-Google-Smtp-Source: ABdhPJyyWHtZNK314x561NUi4PPnX8MrbdIZyQjkBAkwo5J9Q3P2KT4kWz9x6rzrdRkChGnsyQf4Sm4gNm3htA== X-Received: from spirogrip.svl.corp.google.com ([2620:15c:2cb:201:42a8:f0ff:fe4d:3548]) (user=davidgow job=sendgmr) by 2002:a25:6849:: with SMTP id d70mr11302635ybc.117.1599721428940; Thu, 10 Sep 2020 00:03:48 -0700 (PDT) Date: Thu, 10 Sep 2020 00:03:29 -0700 In-Reply-To: <20200910070331.3358048-1-davidgow@google.com> Message-Id: <20200910070331.3358048-5-davidgow@google.com> Mime-Version: 1.0 References: <20200910070331.3358048-1-davidgow@google.com> X-Mailer: git-send-email 2.28.0.526.ge36021eeef-goog Subject: [PATCH v13 4/5] KASAN: Testing Documentation From: David Gow To: trishalfonso@google.com, brendanhiggins@google.com, aryabinin@virtuozzo.com, dvyukov@google.com, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, andreyknvl@google.com, shuah@kernel.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, David Gow Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Patricia Alfonso Include documentation on how to test KASAN using CONFIG_TEST_KASAN_KUNIT and CONFIG_TEST_KASAN_MODULE. Signed-off-by: Patricia Alfonso Signed-off-by: David Gow Reviewed-by: Andrey Konovalov Reviewed-by: Dmitry Vyukov Acked-by: Brendan Higgins Tested-by: Andrey Konovalov --- Documentation/dev-tools/kasan.rst | 70 +++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst index 38fd5681fade..072ecdadba07 100644 --- a/Documentation/dev-tools/kasan.rst +++ b/Documentation/dev-tools/kasan.rst @@ -281,3 +281,73 @@ unmapped. This will require changes in arch-specific code. This allows ``VMAP_STACK`` support on x86, and can simplify support of architectures that do not have a fixed module region. + +CONFIG_KASAN_KUNIT_TEST & CONFIG_TEST_KASAN_MODULE +-------------------------------------------------- + +``CONFIG_KASAN_KUNIT_TEST`` utilizes the KUnit Test Framework for testing. +This means each test focuses on a small unit of functionality and +there are a few ways these tests can be run. + +Each test will print the KASAN report if an error is detected and then +print the number of the test and the status of the test: + +pass:: + + ok 28 - kmalloc_double_kzfree +or, if kmalloc failed:: + + # kmalloc_large_oob_right: ASSERTION FAILED at lib/test_kasan.c:163 + Expected ptr is not null, but is + not ok 4 - kmalloc_large_oob_right +or, if a KASAN report was expected, but not found:: + + # kmalloc_double_kzfree: EXPECTATION FAILED at lib/test_kasan.c:629 + Expected kasan_data->report_expected == kasan_data->report_found, but + kasan_data->report_expected == 1 + kasan_data->report_found == 0 + not ok 28 - kmalloc_double_kzfree + +All test statuses are tracked as they run and an overall status will +be printed at the end:: + + ok 1 - kasan + +or:: + + not ok 1 - kasan + +(1) Loadable Module +~~~~~~~~~~~~~~~~~~~~ + +With ``CONFIG_KUNIT`` enabled, ``CONFIG_KASAN_KUNIT_TEST`` can be built as +a loadable module and run on any architecture that supports KASAN +using something like insmod or modprobe. The module is called ``test_kasan``. + +(2) Built-In +~~~~~~~~~~~~~ + +With ``CONFIG_KUNIT`` built-in, ``CONFIG_KASAN_KUNIT_TEST`` can be built-in +on any architecure that supports KASAN. These and any other KUnit +tests enabled will run and print the results at boot as a late-init +call. + +(3) Using kunit_tool +~~~~~~~~~~~~~~~~~~~~~ + +With ``CONFIG_KUNIT`` and ``CONFIG_KASAN_KUNIT_TEST`` built-in, we can also +use kunit_tool to see the results of these along with other KUnit +tests in a more readable way. This will not print the KASAN reports +of tests that passed. Use `KUnit documentation `_ for more up-to-date +information on kunit_tool. + +.. _KUnit: https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html + +``CONFIG_TEST_KASAN_MODULE`` is a set of KASAN tests that could not be +converted to KUnit. These tests can be run only as a module with +``CONFIG_TEST_KASAN_MODULE`` built as a loadable module and +``CONFIG_KASAN`` built-in. The type of error expected and the +function being run is printed before the expression expected to give +an error. Then the error is printed, if found, and that test +should be interpretted to pass only if the error was the one expected +by the test.