Messages in this thread Patch in this message | | | From | paulmck@kernel ... | Subject | [PATCH tip/core/rcu 10/10] kcsan: Add jiffies test to test suite | Date | Mon, 22 Jun 2020 17:43:33 -0700 |
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From: Marco Elver <elver@google.com>
Add a test that KCSAN nor the compiler gets confused about accesses to jiffies on different architectures.
Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- kernel/kcsan/kcsan-test.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/kernel/kcsan/kcsan-test.c b/kernel/kcsan/kcsan-test.c index 3af420a..fed6fcb 100644 --- a/kernel/kcsan/kcsan-test.c +++ b/kernel/kcsan/kcsan-test.c @@ -366,6 +366,11 @@ static noinline void test_kernel_read_struct_zero_size(void) kcsan_check_read(&test_struct.val[3], 0); } +static noinline void test_kernel_jiffies_reader(void) +{ + sink_value((long)jiffies); +} + static noinline void test_kernel_seqlock_reader(void) { unsigned int seq; @@ -817,6 +822,23 @@ static void test_assert_exclusive_access_scoped(struct kunit *test) KUNIT_EXPECT_TRUE(test, match_expect_inscope); } +/* + * jiffies is special (declared to be volatile) and its accesses are typically + * not marked; this test ensures that the compiler nor KCSAN gets confused about + * jiffies's declaration on different architectures. + */ +__no_kcsan +static void test_jiffies_noreport(struct kunit *test) +{ + bool match_never = false; + + begin_test_checks(test_kernel_jiffies_reader, test_kernel_jiffies_reader); + do { + match_never = report_available(); + } while (!end_test_checks(match_never)); + KUNIT_EXPECT_FALSE(test, match_never); +} + /* Test that racing accesses in seqlock critical sections are not reported. */ __no_kcsan static void test_seqlock_noreport(struct kunit *test) @@ -867,6 +889,7 @@ static struct kunit_case kcsan_test_cases[] = { KCSAN_KUNIT_CASE(test_assert_exclusive_bits_nochange), KCSAN_KUNIT_CASE(test_assert_exclusive_writer_scoped), KCSAN_KUNIT_CASE(test_assert_exclusive_access_scoped), + KCSAN_KUNIT_CASE(test_jiffies_noreport), KCSAN_KUNIT_CASE(test_seqlock_noreport), {}, }; -- 2.9.5
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