From: Thomas Gleixner Date: Mon, 27 Oct 2025 08:43:52 +0000 (+0100) Subject: s390/uaccess: Use unsafe wrappers for ASM GOTO X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=43cc54d8dbe6b761bd2672bf9bb46e5290e90277;p=thirdparty%2Fkernel%2Flinux.git s390/uaccess: Use unsafe wrappers for ASM GOTO ASM GOTO is miscompiled by GCC when it is used inside a auto cleanup scope: bool foo(u32 __user *p, u32 val) { scoped_guard(pagefault) unsafe_put_user(val, p, efault); return true; efault: return false; } It ends up leaking the pagefault disable counter in the fault path. clang at least fails the build. S390 is not affected for unsafe_*_user() as it uses its own local label already, but __get/put_kernel_nofault() lack that. Rename them to arch_*_kernel_nofault() which makes the generic uaccess header wrap it with a local label that makes both compilers emit correct code. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Mathieu Desnoyers Acked-by: Heiko Carstens Link: https://patch.msgid.link/20251027083745.483079889@linutronix.de --- diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index 3e5b8b6770571..c5e02addcd67f 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -468,8 +468,8 @@ do { \ #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT && CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS */ -#define __get_kernel_nofault __mvc_kernel_nofault -#define __put_kernel_nofault __mvc_kernel_nofault +#define arch_get_kernel_nofault __mvc_kernel_nofault +#define arch_put_kernel_nofault __mvc_kernel_nofault void __cmpxchg_user_key_called_with_bad_pointer(void);