X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=lib%2Ftest_kasan.c;h=cacbbbdef768d056d010ebde123353192f502c50;hb=57143f2e5b41f3e51b13d3c358e29a932334110d;hp=785e724ce0d8881b780ca4602d2b871d90ff9093;hpb=6c0029211382011af508273c4fc98a732f841d95;p=linux-2.6-microblaze.git

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 785e724ce0d8..cacbbbdef768 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -54,6 +54,10 @@ 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;
 }
 
@@ -61,6 +65,7 @@ static void kasan_test_exit(struct kunit *test)
 {
 	kasan_set_tagging_report_once(true);
 	kasan_restore_multi_shot(multishot);
+	KUNIT_EXPECT_FALSE(test, fail_data.report_found);
 }
 
 /**
@@ -78,33 +83,31 @@ static void kasan_test_exit(struct kunit *test)
  * 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.
+ *
+ * In between KUNIT_EXPECT_KASAN_FAIL checks, fail_data.report_found is kept as
+ * false. This allows detecting KASAN reports that happen outside of the checks
+ * by asserting !fail_data.report_found at the start of KUNIT_EXPECT_KASAN_FAIL
+ * and in kasan_test_exit.
  */
-#define KUNIT_EXPECT_KASAN_FAIL(test, expression) do {		\
-	if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&			\
-	    !kasan_async_mode_enabled())			\
-		migrate_disable();				\
-	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();						\
-	if (kasan_async_mode_enabled())				\
-		kasan_force_async_fault();			\
-	barrier();						\
-	KUNIT_EXPECT_EQ(test,					\
-			READ_ONCE(fail_data.report_expected),	\
-			READ_ONCE(fail_data.report_found));	\
-	if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&			\
-	    !kasan_async_mode_enabled()) {			\
-		if (READ_ONCE(fail_data.report_found))		\
-			kasan_enable_tagging_sync();		\
-		migrate_enable();				\
-	}							\
+#define KUNIT_EXPECT_KASAN_FAIL(test, expression) do {			\
+	if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&				\
+	    !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 (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 {			\
@@ -651,8 +654,20 @@ static char global_array[10];
 
 static void kasan_global_oob(struct kunit *test)
 {
-	volatile int i = 3;
-	char *p = &global_array[ARRAY_SIZE(global_array) + i];
+	/*
+	 * Deliberate out-of-bounds access. To prevent CONFIG_UBSAN_LOCAL_BOUNDS
+	 * from failing here and panicing the kernel, access the array via a
+	 * volatile pointer, which will prevent the compiler from being able to
+	 * determine the array bounds.
+	 *
+	 * This access uses a volatile pointer to char (char *volatile) rather
+	 * than the more conventional pointer to volatile char (volatile char *)
+	 * because we want to prevent the compiler from making inferences about
+	 * the pointer itself (i.e. its array bounds), not the data that it
+	 * refers to.
+	 */
+	char *volatile array = global_array;
+	char *p = &array[ARRAY_SIZE(global_array) + 3];
 
 	/* Only generic mode instruments globals. */
 	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
@@ -700,8 +715,9 @@ static void ksize_uaf(struct kunit *test)
 static void kasan_stack_oob(struct kunit *test)
 {
 	char stack_array[10];
-	volatile int i = OOB_TAG_OFF;
-	char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
+	/* See comment in kasan_global_oob. */
+	char *volatile array = stack_array;
+	char *p = &array[ARRAY_SIZE(stack_array) + OOB_TAG_OFF];
 
 	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
 
@@ -712,7 +728,9 @@ static void kasan_alloca_oob_left(struct kunit *test)
 {
 	volatile int i = 10;
 	char alloca_array[i];
-	char *p = alloca_array - 1;
+	/* See comment in kasan_global_oob. */
+	char *volatile array = alloca_array;
+	char *p = array - 1;
 
 	/* Only generic mode instruments dynamic allocas. */
 	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
@@ -725,7 +743,9 @@ static void kasan_alloca_oob_right(struct kunit *test)
 {
 	volatile int i = 10;
 	char alloca_array[i];
-	char *p = alloca_array + i;
+	/* See comment in kasan_global_oob. */
+	char *volatile array = alloca_array;
+	char *p = array + i;
 
 	/* Only generic mode instruments dynamic allocas. */
 	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
@@ -1049,14 +1069,14 @@ static void match_all_mem_tag(struct kunit *test)
 			continue;
 
 		/* Mark the first memory granule with the chosen memory tag. */
-		kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag);
+		kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag, false);
 
 		/* This access must cause a KASAN report. */
 		KUNIT_EXPECT_KASAN_FAIL(test, *ptr = 0);
 	}
 
 	/* Recover the memory tag and free. */
-	kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr));
+	kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr), false);
 	kfree(ptr);
 }