From 3ff16d30f593d80a958104ee06a94562a12c5879 Mon Sep 17 00:00:00 2001 From: David Gow Date: Mon, 28 Jun 2021 19:40:36 -0700 Subject: kasan: test: improve failure message in KUNIT_EXPECT_KASAN_FAIL() The KUNIT_EXPECT_KASAN_FAIL() macro currently uses KUNIT_EXPECT_EQ() to compare fail_data.report_expected and fail_data.report_found. This always gave a somewhat useless error message on failure, but the addition of extra compile-time checking with READ_ONCE() has caused it to get much longer, and be truncated before anything useful is displayed. Instead, just check fail_data.report_found by hand (we've just set report_expected to 'true'), and print a better failure message with KUNIT_FAIL(). Because of this, report_expected is no longer used anywhere, and can be removed. Beforehand, a failure in: KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)area)[3100]); would have looked like: [22:00:34] [FAILED] vmalloc_oob [22:00:34] # vmalloc_oob: EXPECTATION FAILED at lib/test_kasan.c:991 [22:00:34] Expected ({ do { extern void __compiletime_assert_705(void) __attribute__((__error__("Unsupported access size for {READ,WRITE}_ONCE()."))); if (!((sizeof(fail_data.report_expected) == sizeof(char) || sizeof(fail_data.repp [22:00:34] not ok 45 - vmalloc_oob With this change, it instead looks like: [22:04:04] [FAILED] vmalloc_oob [22:04:04] # vmalloc_oob: EXPECTATION FAILED at lib/test_kasan.c:993 [22:04:04] KASAN failure expected in "((volatile char *)area)[3100]", but none occurred [22:04:04] not ok 45 - vmalloc_oob Also update the example failure in the documentation to reflect this. Link: https://lkml.kernel.org/r/20210606005531.165954-1-davidgow@google.com Signed-off-by: David Gow Reviewed-by: Andrey Konovalov Reviewed-by: Marco Elver Acked-by: Brendan Higgins Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Daniel Axtens Cc: David Gow Cc: Jonathan Corbet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/test_kasan.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'lib/test_kasan.c') diff --git a/lib/test_kasan.c b/lib/test_kasan.c index cacbbbdef768..44e08f4d9c52 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -55,7 +55,6 @@ static int kasan_test_init(struct kunit *test) multishot = kasan_save_enable_multi_shot(); kasan_set_tagging_report_once(false); fail_data.report_found = false; - fail_data.report_expected = false; kunit_add_named_resource(test, NULL, NULL, &resource, "kasan_data", &fail_data); return 0; @@ -94,20 +93,20 @@ static void kasan_test_exit(struct kunit *test) !kasan_async_mode_enabled()) \ migrate_disable(); \ KUNIT_EXPECT_FALSE(test, READ_ONCE(fail_data.report_found)); \ - WRITE_ONCE(fail_data.report_expected, true); \ barrier(); \ expression; \ barrier(); \ - KUNIT_EXPECT_EQ(test, \ - READ_ONCE(fail_data.report_expected), \ - READ_ONCE(fail_data.report_found)); \ + if (!READ_ONCE(fail_data.report_found)) { \ + KUNIT_FAIL(test, KUNIT_SUBTEST_INDENT "KASAN failure " \ + "expected in \"" #expression \ + "\", but none occurred"); \ + } \ if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) { \ if (READ_ONCE(fail_data.report_found)) \ kasan_enable_tagging_sync(); \ migrate_enable(); \ } \ WRITE_ONCE(fail_data.report_found, false); \ - WRITE_ONCE(fail_data.report_expected, false); \ } while (0) #define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do { \ -- cgit