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| author | David Gow <davidgow@google.com> | 2021-06-28 19:40:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-29 10:53:52 -0700 |
| commit | 3ff16d30f593d80a958104ee06a94562a12c5879 (patch) | |
| tree | b19afee0567494af9be74c4cc8103339242bf3ae /lib/test_kasan.c | |
| parent | 336abff6e8723c6b98e141372956e6c0c55e8ea4 (diff) | |
| download | lwn-3ff16d30f593d80a958104ee06a94562a12c5879.tar.gz lwn-3ff16d30f593d80a958104ee06a94562a12c5879.zip | |
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 <davidgow@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: David Gow <davidgow@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/test_kasan.c')
| -rw-r--r-- | lib/test_kasan.c | 11 |
1 files changed, 5 insertions, 6 deletions
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 { \ |