The patch titled Subject: kasan/test: fix protection against compiler elision has been added to the -mm mm-hotfixes-unstable branch. Its filename is kasan-test-fix-protection-against-compiler-elision.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ 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-e7157c9af82... 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-test-fix-protection-against-compiler-elision.patch kasan-skip-quarantine-if-object-is-still-accessible-under-rcu.patch mm-rmap-add-anon_vma-lifetime-debug-check.patch