[merged mm-hotfixes-stable] kasan-test-fix-protection-against-compiler-elision.patch removed from -mm tree

[merged mm-hotfixes-stable] kasan-test-fix-protection-against-compiler-elision.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: kasan/test: fix protection against compiler elision
has been removed from the -mm tree.  Its filename was
     kasan-test-fix-protection-against-compiler-elision.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Jann Horn <jannh@google.com>
Subject: kasan/test: fix protection against compiler elision
Date: Mon, 28 Jul 2025 22:11:54 +0200

The kunit test is using assignments to
"static volatile void *kasan_ptr_result" to prevent elision of memory
loads, but that's not working:
In this variable definition, the "volatile" applies to the "void", not to
the pointer.
To make "volatile" apply to the pointer as intended, it must follow
after the "*".

This makes the kasan_memchr test pass again on my system.  The
kasan_strings test is still failing because all the definitions of
load_unaligned_zeropad() are lacking explicit instrumentation hooks and
ASAN does not instrument asm() memory operands.

Link: https://lkml.kernel.org/r/20250728-kasan-kunit-fix-volatile-v1-1-e7157c9af82d@google.com
Fixes: 5f1c8108e7ad ("mm:kasan: fix sparse warnings: Should it be static?")
Signed-off-by: Jann Horn <jannh@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Nihar Chaithanya <niharchaithanya@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kasan/kasan_test_c.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/kasan/kasan_test_c.c~kasan-test-fix-protection-against-compiler-elision
+++ a/mm/kasan/kasan_test_c.c
@@ -47,7 +47,7 @@ static struct {
  * Some tests use these global variables to store return values from function
  * calls that could otherwise be eliminated by the compiler as dead code.
  */
-static volatile void *kasan_ptr_result;
+static void *volatile kasan_ptr_result;
 static volatile int kasan_int_result;
 
 /* Probe for console output: obtains test_status lines of interest. */
_

Patches currently in -mm which might be from jannh@google.com are

kasan-add-test-for-slab_typesafe_by_rcu-quarantine-skipping.patch
kasan-add-test-for-slab_typesafe_by_rcu-quarantine-skipping-v2.patch