kfence: test: use kunit_skip() to skip tests

Use the new kunit_skip() to skip tests if requirements were not met.  It
makes it easier to see in KUnit's summary if there were skipped tests.

Link: https://lkml.kernel.org/r/20210922182541.1372400-1-elver@google.comSigned-off-by: Marco Elver <elver@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/kfence/kfence_test.c

@@ -32,6 +32,11 @@
 #define arch_kfence_test_address(addr) (addr)
 #endif
 
+#define KFENCE_TEST_REQUIRES(test, cond) do {			\
+	if (!(cond))						\
+		kunit_skip((test), "Test requires: " #cond);	\
+} while (0)
+
 /* Report as observed from console. */
 static struct {
 	spinlock_t lock;
@@ -555,8 +560,7 @@ static void test_init_on_free(struct kunit *test)
 	};
 	int i;
 
-	if (!IS_ENABLED(CONFIG_INIT_ON_FREE_DEFAULT_ON))
-		return;
+	KFENCE_TEST_REQUIRES(test, IS_ENABLED(CONFIG_INIT_ON_FREE_DEFAULT_ON));
 	/* Assume it hasn't been disabled on command line. */
 
 	setup_test_cache(test, size, 0, NULL);
@@ -603,10 +607,8 @@ static void test_gfpzero(struct kunit *test)
 	char *buf1, *buf2;
 	int i;
 
-	if (CONFIG_KFENCE_SAMPLE_INTERVAL > 100) {
-		kunit_warn(test, "skipping ... would take too long\n");
-		return;
-	}
+	/* Skip if we think it'd take too long. */
+	KFENCE_TEST_REQUIRES(test, CONFIG_KFENCE_SAMPLE_INTERVAL <= 100);
 
 	setup_test_cache(test, size, 0, NULL);
 	buf1 = test_alloc(test, size, GFP_KERNEL, ALLOCATE_ANY);