slub: kunit catch kmem_cache_alloc failed

Catch kmem_cache_alloc failed on slub kunit test.

Signed-off-by: Paran Lee <p4ranlee@gmail.com>

lib/slub_kunit.c

@@ -32,6 +32,11 @@ static void test_next_pointer(struct kunit *test)
 	struct kmem_cache *s = kmem_cache_create("TestSlub_next_ptr_free", 64, 0,
 				SLAB_POISON, NULL);
 	u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
+	if (!p) {
+		kunit_err(test, "Allocation failed: %s\n", __func__);
+		kmem_cache_destroy(s);
+		return;
+	}
 	unsigned long tmp;
 	unsigned long *ptr_addr;
 
@@ -77,6 +82,11 @@ static void test_first_word(struct kunit *test)
 	struct kmem_cache *s = kmem_cache_create("TestSlub_1th_word_free", 64, 0,
 				SLAB_POISON, NULL);
 	u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
+	if (!p) {
+		kunit_err(test, "Allocation failed: %s\n", __func__);
+		kmem_cache_destroy(s);
+		return;
+	}
 
 	kmem_cache_free(s, p);
 	*p = 0x78;
@@ -92,6 +102,11 @@ static void test_clobber_50th_byte(struct kunit *test)
 	struct kmem_cache *s = kmem_cache_create("TestSlub_50th_word_free", 64, 0,
 				SLAB_POISON, NULL);
 	u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
+	if (!p) {
+		kunit_err(test, "Allocation failed: %s\n", __func__);
+		kmem_cache_destroy(s);
+		return;
+	}
 
 	kmem_cache_free(s, p);
 	p[50] = 0x9a;
@@ -108,6 +123,11 @@ static void test_clobber_redzone_free(struct kunit *test)
 	struct kmem_cache *s = kmem_cache_create("TestSlub_RZ_free", 64, 0,
 				SLAB_RED_ZONE, NULL);
 	u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
+	if (!p) {
+		kunit_err(test, "Allocation failed: %s\n", __func__);
+		kmem_cache_destroy(s);
+		return;
+	}
 
 	kasan_disable_current();
 	kmem_cache_free(s, p);