From patchwork Tue Sep 15 03:58:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gow X-Patchwork-Id: 11775457 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 8213F618 for ; Tue, 15 Sep 2020 03:58:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6267A20936 for ; Tue, 15 Sep 2020 03:58:57 +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="HPKahaLV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726155AbgIOD6z (ORCPT ); Mon, 14 Sep 2020 23:58:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726146AbgIOD6r (ORCPT ); Mon, 14 Sep 2020 23:58:47 -0400 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 266E0C061797 for ; Mon, 14 Sep 2020 20:58:46 -0700 (PDT) Received: by mail-qk1-x74a.google.com with SMTP id 139so2002417qkl.11 for ; Mon, 14 Sep 2020 20:58:46 -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=uCglP5LX985FGF4m2PQOWOUblsVZfIf8g+EYcPDK67c=; b=HPKahaLV0BRynEGp6ZaODFkiwQm1KiRc4qKnG7F0a72KRtJLIW+kK9HpYePY+PelRW kqfvCu5DTIS8RLAsyz6LsWwQgIXFxbSIfKdVQqZBtt/kzQAuUjER20J4MM1AeRBjbe9N 1sjCzqqF0ugnAnz2WCZfARgqOotVf2e9fB6j9OicYUNrSV035CoRTjhwoJ48YTLd8nC6 taGtf0mqTakdfcWbUXx+q4JRFdl/cRzBjusPvSdNxI4i8lKIiyWedjAjB6NjVl/1MuEl ai4RGLJ46opkRsumeRA6bG1+fRtGQoHJ7G0N/G7QdhixURMVxgOl8tC2v9Be21dh8p/U Qs4g== 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=uCglP5LX985FGF4m2PQOWOUblsVZfIf8g+EYcPDK67c=; b=NiwRe2RiNjEgjgenZzO8OgEyWAe6YHVHlYRGB59iBXHbeTB4kDgUjkqe2mHYjLvM0y DFqXvi3uzzeulkqmmdEC/PF2y/3dptiIK6g4KFHCI21QLyYvwxxte470w+vREAiWqKZR uKD79Rq45t+2MAX4Gxe/xCQW+6Tv9UPvuwQwkuz/huRsmgU5ZuDR7wyTEauGtt68kINv 2Mlb8B7PBTlUGr+CF4Qw1ZogL7MO7erEnWIVmCI6OPZDrCLhw4qSjTl0VwOVNj6VFl9E g8DyB85ocx+1u9FsY8WC8YmrrGXJwEFBCQWPRtP2ZMZzE/c+ZH8U+V888mH6AZ04TP+j WC8g== X-Gm-Message-State: AOAM531vVIqIJtZMwkPYVN5aVUAEpkWX2i0GoN9Ldi8qDFcCxVJ9RPgP LbAKipEZuME23osuj28GfuJQ/L/vfRbeXg== X-Google-Smtp-Source: ABdhPJzwoiMnTkw6yQ4Uu2gGaOfIAl6aoYI/Wx2A+phY8mopGuZDP+JJBXzJsVOGJLcvnpOIpt/sx8ONxdq62Q== X-Received: from spirogrip.svl.corp.google.com ([2620:15c:2cb:201:42a8:f0ff:fe4d:3548]) (user=davidgow job=sendgmr) by 2002:a0c:f48e:: with SMTP id i14mr16532536qvm.9.1600142325247; Mon, 14 Sep 2020 20:58:45 -0700 (PDT) Date: Mon, 14 Sep 2020 20:58:27 -0700 In-Reply-To: <20200915035828.570483-1-davidgow@google.com> Message-Id: <20200915035828.570483-5-davidgow@google.com> Mime-Version: 1.0 References: <20200915035828.570483-1-davidgow@google.com> X-Mailer: git-send-email 2.28.0.618.gf4bc123cb7-goog Subject: [PATCH v14 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.