kasan: fix more unit tests with CONFIG_UBSAN_LOCAL_BOUNDS enabled

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 <[email protected]>

Cc <[email protected]> # 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(-)

lib/test_kasan.c +0 -0

index 26a5c9007653..3bf8801d0e66 100644

lib/test_kasan.c +4 -3

        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

Quoted 19 lines · Peter Collingbourne

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 <[email protected]>

Cc <[email protected]> # 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(-)

lib/test_kasan.c +0 -0

index 26a5c9007653..3bf8801d0e66 100644

lib/test_kasan.c static void kmalloc_node_oob_right(struct kunit *test) · line 182

Quoted 7 lines

lib/test_kasan.c +2 -1

@@ -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;

I think more recently we've been using OPTIMIZER_HIDE_VAR() to hide things from the compiler. Does OPTIMIZER_HIDE_VAR(ptr) right before the access also work in this case?

I leave it to you which you think is cleaner - I'm guessing that we might want to avoid volatile if we can.