kasan: test: support async (again) and asymm modes for HW_TAGS

Async mode support has already been implemented in commit e80a76aa1a91
("kasan, arm64: tests supports for HW_TAGS async mode") but then got
accidentally broken in commit 99734b535d9b ("kasan: detect false-positives
in tests").

Restore the changes removed by the latter patch and adapt them for asymm
mode: add a sync_fault flag to kunit_kasan_expectation that only get set
if the MTE fault was synchronous, and reenable MTE on such faults in
tests.

Also rename kunit_kasan_expectation to kunit_kasan_status and move its
definition to mm/kasan/kasan.h from include/linux/kasan.h, as this
structure is only internally used by KASAN.  Also put the structure
definition under IS_ENABLED(CONFIG_KUNIT).

Link: https://lkml.kernel.org/r/133970562ccacc93ba19d754012c562351d4a8c8.1645033139.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 30 insertions, 19 deletions

diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index fad1887e54c0..07a76c46daa5 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -172,12 +172,7 @@ void kasan_init_hw_tags_cpu(void)
 	 * Enable async or asymm modes only when explicitly requested
 	 * through the command line.
 	 */
-	if (kasan_arg_mode == KASAN_ARG_MODE_ASYNC)
-		hw_enable_tagging_async();
-	else if (kasan_arg_mode == KASAN_ARG_MODE_ASYMM)
-		hw_enable_tagging_asymm();
-	else
-		hw_enable_tagging_sync();
+	kasan_enable_tagging();
 }
 
 /* kasan_init_hw_tags() is called once on boot CPU. */
@@ -343,11 +338,16 @@ void __kasan_poison_vmalloc(const void *start, unsigned long size)
 
 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
 
-void kasan_enable_tagging_sync(void)
+void kasan_enable_tagging(void)
 {
-	hw_enable_tagging_sync();
+	if (kasan_arg_mode == KASAN_ARG_MODE_ASYNC)
+		hw_enable_tagging_async();
+	else if (kasan_arg_mode == KASAN_ARG_MODE_ASYMM)
+		hw_enable_tagging_asymm();
+	else
+		hw_enable_tagging_sync();
 }
-EXPORT_SYMBOL_GPL(kasan_enable_tagging_sync);
+EXPORT_SYMBOL_GPL(kasan_enable_tagging);
 
 void kasan_force_async_fault(void)
 {
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 4d67408e8407..d1e111b7d5d8 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -7,6 +7,16 @@
 #include <linux/kfence.h>
 #include <linux/stackdepot.h>
 
+#if IS_ENABLED(CONFIG_KUNIT)
+
+/* Used in KUnit-compatible KASAN tests. */
+struct kunit_kasan_status {
+	bool report_found;
+	bool sync_fault;
+};
+
+#endif
+
 #ifdef CONFIG_KASAN_HW_TAGS
 
 #include <linux/static_key.h>
@@ -350,12 +360,12 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 
 #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
 
-void kasan_enable_tagging_sync(void);
+void kasan_enable_tagging(void);
 void kasan_force_async_fault(void);
 
 #else /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */
 
-static inline void kasan_enable_tagging_sync(void) { }
+static inline void kasan_enable_tagging(void) { }
 static inline void kasan_force_async_fault(void) { }
 
 #endif /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index f14146563d41..137c2c0b09db 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -336,20 +336,21 @@ static bool report_enabled(void)
 }
 
 #if IS_ENABLED(CONFIG_KUNIT)
-static void kasan_update_kunit_status(struct kunit *cur_test)
+static void kasan_update_kunit_status(struct kunit *cur_test, bool sync)
 {
 	struct kunit_resource *resource;
-	struct kunit_kasan_expectation *kasan_data;
+	struct kunit_kasan_status *status;
 
-	resource = kunit_find_named_resource(cur_test, "kasan_data");
+	resource = kunit_find_named_resource(cur_test, "kasan_status");
 
 	if (!resource) {
 		kunit_set_failure(cur_test);
 		return;
 	}
 
-	kasan_data = (struct kunit_kasan_expectation *)resource->data;
-	WRITE_ONCE(kasan_data->report_found, true);
+	status = (struct kunit_kasan_status *)resource->data;
+	WRITE_ONCE(status->report_found, true);
+	WRITE_ONCE(status->sync_fault, sync);
 	kunit_put_resource(resource);
 }
 #endif /* IS_ENABLED(CONFIG_KUNIT) */
@@ -363,7 +364,7 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
 
 #if IS_ENABLED(CONFIG_KUNIT)
 	if (current->kunit_test)
-		kasan_update_kunit_status(current->kunit_test);
+		kasan_update_kunit_status(current->kunit_test, true);
 #endif /* IS_ENABLED(CONFIG_KUNIT) */
 
 	start_report(&flags);
@@ -383,7 +384,7 @@ void kasan_report_async(void)
 
 #if IS_ENABLED(CONFIG_KUNIT)
 	if (current->kunit_test)
-		kasan_update_kunit_status(current->kunit_test);
+		kasan_update_kunit_status(current->kunit_test, false);
 #endif /* IS_ENABLED(CONFIG_KUNIT) */
 
 	start_report(&flags);
@@ -405,7 +406,7 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write,
 
 #if IS_ENABLED(CONFIG_KUNIT)
 	if (current->kunit_test)
-		kasan_update_kunit_status(current->kunit_test);
+		kasan_update_kunit_status(current->kunit_test, true);
 #endif /* IS_ENABLED(CONFIG_KUNIT) */
 
 	disable_trace_on_warning();