From patchwork Wed Jan 13 16:21:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 12017275 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E166C433E0 for ; Wed, 13 Jan 2021 16:21:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 786182313C for ; Wed, 13 Jan 2021 16:21:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 786182313C Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C5CF28D006D; Wed, 13 Jan 2021 11:21:55 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C365C8D006C; Wed, 13 Jan 2021 11:21:55 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A85508D006D; Wed, 13 Jan 2021 11:21:55 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0072.hostedemail.com [216.40.44.72]) by kanga.kvack.org (Postfix) with ESMTP id 9272B8D006C for ; Wed, 13 Jan 2021 11:21:55 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 55ACA1F1B for ; Wed, 13 Jan 2021 16:21:55 +0000 (UTC) X-FDA: 77701268190.14.nail62_310d0d62751f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin14.hostedemail.com (Postfix) with ESMTP id 36449182299A7 for ; Wed, 13 Jan 2021 16:21:55 +0000 (UTC) X-HE-Tag: nail62_310d0d62751f X-Filterd-Recvd-Size: 9811 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) by imf22.hostedemail.com (Postfix) with ESMTP for ; Wed, 13 Jan 2021 16:21:54 +0000 (UTC) Received: by mail-wm1-f73.google.com with SMTP id k67so1026087wmk.5 for ; Wed, 13 Jan 2021 08:21:54 -0800 (PST) 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=m6xusvsokM0PWzPtRFY43dxv0DbWG+gsyZsDZx85iWg=; b=oIZpxTscmzWNn6FCdK0QAMEb22GI8TtyGOSGYp0n9CCiJsPBVaS88difbiciw2Y/WA ll5wL0LrrITPb7IsDp6lk4BhoYUX7XC4JEBntwtKkumgvD4lDnPRRlyGxtXNDin/htC4 WS84mFmlyahT5AR+NGIWNl2yA9pj85zk/jqZul/99RhfROiS8Z+sFZbs3dWsZjcb+eMX EQT9+/tAoTnv9tblI+CRR9ba2rO+yB3gScfPu4MeABpZyuuoGnUj6ymZT/hwOOTAzwwu zROA1X9gInEn71Ef5S/DouuF0FyHRQy8EgQmpuV1WLSWstqvvipbKpb8GkhBdAeDAR6h 8+Ug== 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=m6xusvsokM0PWzPtRFY43dxv0DbWG+gsyZsDZx85iWg=; b=Cc9hqSBmQ90GqSh1K4aJLq0HSQJJMi5/wXVo1zhAhqD72MEF7FB+5mnnWa0xsSjzVa DIUkeGnePLlsE9XpMnoaYSrY7nlpcwCSO3O+dOmLWspDQr3t2y2o4LU7ei5jfFipeJW3 1sagqRCcn5V5vKS4+Jq8ao0YoyAxRa9QuqnCCj9dIRBxW+Q20H10/NRZFor4Yt0md02A 64h8Zp1GcsOpyh20XhFHlEgYbb+IxXU9hZkw1l/LKLschyvxVRrVpj/MoCKGnZd3Jib4 2tILpTKZ2+hnhQQ2GVqTn8iqscvsgcOJwNC3RrmheyN+7OLD2ouyH+RE8J+cUj0QlMmq H3ag== X-Gm-Message-State: AOAM530FAh+TQ7VQ96Ai0suTbgOs+mm4G3hy58Ox6QEI+qtmoYnh0ibN nYDJlY50cQq72n5//ofT8iPxDOu1Dy3fd7Yh X-Google-Smtp-Source: ABdhPJxarFcYjl7xb1/SRC825R68ZOFC+U25rfLA2+9VuJbqvx76lMLxU2yiun2kPDZt20pEdQ2iKQIZgc/jbIUL X-Received: from andreyknvl3.muc.corp.google.com ([2a00:79e0:15:13:7220:84ff:fe09:7e9d]) (user=andreyknvl job=sendgmr) by 2002:a05:600c:4154:: with SMTP id h20mr66423wmm.72.1610554913410; Wed, 13 Jan 2021 08:21:53 -0800 (PST) Date: Wed, 13 Jan 2021 17:21:30 +0100 In-Reply-To: Message-Id: <2b43049e25dcd04850ba6c205cd6dcc7caa4a886.1610554432.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH v2 03/14] kasan: clean up comments in tests From: Andrey Konovalov To: Catalin Marinas , Vincenzo Frascino , Dmitry Vyukov , Alexander Potapenko , Marco Elver Cc: Andrew Morton , Will Deacon , Andrey Ryabinin , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Clarify and update comments in KASAN tests. Link: https://linux-review.googlesource.com/id/I6c816c51fa1e0eb7aa3dead6bda1f339d2af46c8 Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver --- lib/test_kasan.c | 59 +++++++++++++++++++++++++---------------- lib/test_kasan_module.c | 5 ++-- 2 files changed, 39 insertions(+), 25 deletions(-) diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 2947274cc2d3..6f46e27c2af7 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -28,10 +28,9 @@ #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE) /* - * We assign some test results to these globals to make sure the tests - * are not eliminated as dead code. + * Some tests use these global variables to store return values from function + * calls that could otherwise be eliminated by the compiler as dead code. */ - void *kasan_ptr_result; int kasan_int_result; @@ -39,14 +38,13 @@ static struct kunit_resource resource; static struct kunit_kasan_expectation fail_data; static bool multishot; +/* + * Temporarily enable multi-shot mode. Otherwise, KASAN would only report the + * first detected bug and panic the kernel if panic_on_warn is enabled. + */ static int kasan_test_init(struct kunit *test) { - /* - * Temporarily enable multi-shot mode and set panic_on_warn=0. - * Otherwise, we'd only get a report for the first case. - */ multishot = kasan_save_enable_multi_shot(); - return 0; } @@ -56,12 +54,12 @@ static void kasan_test_exit(struct kunit *test) } /** - * KUNIT_EXPECT_KASAN_FAIL() - Causes a test failure when the expression does - * not cause a KASAN error. This uses a KUnit resource named "kasan_data." Do - * Do not use this name for a KUnit resource outside here. - * + * KUNIT_EXPECT_KASAN_FAIL() - check that the executed expression produces a + * KASAN report; causes a test failure otherwise. This relies on a KUnit + * resource named "kasan_data". Do not use this name for KUnit resources + * outside of KASAN tests. */ -#define KUNIT_EXPECT_KASAN_FAIL(test, condition) do { \ +#define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \ fail_data.report_expected = true; \ fail_data.report_found = false; \ kunit_add_named_resource(test, \ @@ -69,7 +67,7 @@ static void kasan_test_exit(struct kunit *test) NULL, \ &resource, \ "kasan_data", &fail_data); \ - condition; \ + expression; \ KUNIT_EXPECT_EQ(test, \ fail_data.report_expected, \ fail_data.report_found); \ @@ -121,7 +119,8 @@ static void kmalloc_pagealloc_oob_right(struct kunit *test) return; } - /* Allocate a chunk that does not fit into a SLUB cache to trigger + /* + * Allocate a chunk that does not fit into a SLUB cache to trigger * the page allocator fallback. */ ptr = kmalloc(size, GFP_KERNEL); @@ -168,7 +167,9 @@ static void kmalloc_large_oob_right(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE - 256; - /* Allocate a chunk that is large enough, but still fits into a slab + + /* + * Allocate a chunk that is large enough, but still fits into a slab * and does not trigger the page allocator fallback in SLUB. */ ptr = kmalloc(size, GFP_KERNEL); @@ -469,10 +470,13 @@ static void ksize_unpoisons_memory(struct kunit *test) ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); real_size = ksize(ptr); - /* This access doesn't trigger an error. */ + + /* This access shouldn't trigger a KASAN report. */ ptr[size] = 'x'; - /* This one does. */ + + /* This one must. */ KUNIT_EXPECT_KASAN_FAIL(test, ptr[real_size] = 'y'); + kfree(ptr); } @@ -568,7 +572,7 @@ static void kmem_cache_invalid_free(struct kunit *test) return; } - /* Trigger invalid free, the object doesn't get freed */ + /* Trigger invalid free, the object doesn't get freed. */ KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1)); /* @@ -585,7 +589,10 @@ static void kasan_memchr(struct kunit *test) char *ptr; size_t size = 24; - /* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */ + /* + * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT. + * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details. + */ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { kunit_info(test, "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT"); @@ -610,7 +617,10 @@ static void kasan_memcmp(struct kunit *test) size_t size = 24; int arr[9]; - /* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */ + /* + * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT. + * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details. + */ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { kunit_info(test, "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT"); @@ -634,7 +644,10 @@ static void kasan_strings(struct kunit *test) char *ptr; size_t size = 24; - /* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */ + /* + * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT. + * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details. + */ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { kunit_info(test, "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT"); @@ -706,7 +719,7 @@ static void kasan_bitops_generic(struct kunit *test) } /* - * Allocate 1 more byte, which causes kzalloc to round up to 16-bytes; + * Allocate 1 more byte, which causes kzalloc to round up to 16 bytes; * this way we do not actually corrupt other memory. */ bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL); diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c index 3b4cc77992d2..eee017ff8980 100644 --- a/lib/test_kasan_module.c +++ b/lib/test_kasan_module.c @@ -123,8 +123,9 @@ static noinline void __init kasan_workqueue_uaf(void) static int __init test_kasan_module_init(void) { /* - * Temporarily enable multi-shot mode. Otherwise, we'd only get a - * report for the first case. + * Temporarily enable multi-shot mode. Otherwise, KASAN would only + * report the first detected bug and panic the kernel if panic_on_warn + * is enabled. */ bool multishot = kasan_save_enable_multi_shot();