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authorMarco Elver <elver@google.com>2020-06-16 14:36:25 +0200
committerPaul E. McKenney <paulmck@kernel.org>2020-06-29 12:04:48 -0700
commit56b031f0abf55254d47a329010574733fa9a27b8 (patch)
tree1ebb61b07a171c4f663dca0c47a69eb1d5a57e5f /kernel/kcsan
parent7e766560e6e2c1cf2782f00e63c31564e4c9f0fe (diff)
downloadlinux-56b031f0abf55254d47a329010574733fa9a27b8.tar.bz2
kcsan: Add jiffies test to test suite
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>
Diffstat (limited to 'kernel/kcsan')
-rw-r--r--kernel/kcsan/kcsan-test.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/kcsan/kcsan-test.c b/kernel/kcsan/kcsan-test.c
index 3af420ad6ee7..fed6fcb5768c 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),
{},
};