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-rw-r--r--lib/test_kasan.c17
-rw-r--r--mm/kasan/report.c2
2 files changed, 13 insertions, 6 deletions
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 502709db41c0..603fd7937b94 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -68,23 +68,30 @@ static void kasan_test_exit(struct kunit *test)
* normally auto-disabled. When this happens, this test handler reenables
* tag checking. As tag checking can be only disabled or enabled per CPU, this
* handler disables migration (preemption).
+ *
+ * Since the compiler doesn't see that the expression can change the fail_data
+ * fields, it can reorder or optimize away the accesses to those fields.
+ * Use READ/WRITE_ONCE() for the accesses and compiler barriers around the
+ * expression to prevent that.
*/
#define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \
if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) \
migrate_disable(); \
- fail_data.report_expected = true; \
- fail_data.report_found = false; \
+ WRITE_ONCE(fail_data.report_expected, true); \
+ WRITE_ONCE(fail_data.report_found, false); \
kunit_add_named_resource(test, \
NULL, \
NULL, \
&resource, \
"kasan_data", &fail_data); \
+ barrier(); \
expression; \
+ barrier(); \
KUNIT_EXPECT_EQ(test, \
- fail_data.report_expected, \
- fail_data.report_found); \
+ READ_ONCE(fail_data.report_expected), \
+ READ_ONCE(fail_data.report_found)); \
if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) { \
- if (fail_data.report_found) \
+ if (READ_ONCE(fail_data.report_found)) \
kasan_enable_tagging(); \
migrate_enable(); \
} \
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index e93d7973792e..234f35a84f19 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -331,7 +331,7 @@ static void kasan_update_kunit_status(struct kunit *cur_test)
}
kasan_data = (struct kunit_kasan_expectation *)resource->data;
- kasan_data->report_found = true;
+ WRITE_ONCE(kasan_data->report_found, true);
kunit_put_resource(resource);
}
#endif /* IS_ENABLED(CONFIG_KUNIT) */