[PATCH] kasan: fix more unit tests with CONFIG_UBSAN_LOCAL_BOUNDS enabled

[Peter Collingbourne <pcc@google.com>]

This is a followup to commit f649dc0e0d7b ("kasan: fix unit tests
with CONFIG_UBSAN_LOCAL_BOUNDS enabled") that fixes tests that fail
as a result of __alloc_size annotations being added to the kernel
allocator functions.

Link: https://linux-review.googlesource.com/id/I4334cafc5db600fda5cebb851b2ee9fd09fb46cc
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: <stable@vger.kernel.org> # 5.16.x
Fixes: c37495d6254c ("slab: add __alloc_size attributes for better bounds checking")
---
 lib/test_kasan.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 26a5c9007653..3bf8801d0e66 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -177,7 +177,8 @@ static void kmalloc_node_oob_right(struct kunit *test)
  */
 static void kmalloc_pagealloc_oob_right(struct kunit *test)
 {
-	char *ptr;
+	/* See comment in kasan_global_oob_right. */
+	char *volatile ptr;
 	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
 
 	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
@@ -272,7 +273,8 @@ static void kmalloc_large_oob_right(struct kunit *test)
 static void krealloc_more_oob_helper(struct kunit *test,
 					size_t size1, size_t size2)
 {
-	char *ptr1, *ptr2;
+	/* See comment in kasan_global_oob_right. */
+	char *ptr1, *volatile ptr2;
 	size_t middle;
 
 	KUNIT_ASSERT_LT(test, size1, size2);
@@ -304,7 +306,8 @@ static void krealloc_more_oob_helper(struct kunit *test,
 static void krealloc_less_oob_helper(struct kunit *test,
 					size_t size1, size_t size2)
 {
-	char *ptr1, *ptr2;
+	/* See comment in kasan_global_oob_right. */
+	char *ptr1, *volatile ptr2;
 	size_t middle;
 
 	KUNIT_ASSERT_LT(test, size2, size1);
-- 
2.35.1.473.g83b2b277ed-goog