From 148d5494258b4e6f9831045a6191396604795841 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Tue, 30 Apr 2024 16:30:01 +0200 Subject: [PATCH] s390: Mark psw in __load_psw_mask() as __unitialized [ Upstream commit 7278a8fb8d032dfdc03d9b5d17e0bc451cdc1492 ] Without __unitialized, the following code is generated when INIT_STACK_ALL_ZERO is enabled: 86: d7 0f f0 a0 f0 a0 xc 160(16,%r15), 160(%r15) 8c: e3 40 f0 a0 00 24 stg %r4, 160(%r15) 92: c0 10 00 00 00 08 larl %r1, 0xa2 98: e3 10 f0 a8 00 24 stg %r1, 168(%r15) 9e: b2 b2 f0 a0 lpswe 160(%r15) The xc is not adding any security because psw is fully initialized with the following instructions. Add __unitialized to the psw definitiation to avoid the superfluous clearing of psw. Reviewed-by: Heiko Carstens Signed-off-by: Sven Schnelle Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin --- arch/s390/include/asm/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 0987c3fc45f5..95ed01a3536c 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -252,8 +252,8 @@ static inline void __load_psw(psw_t psw) */ static __always_inline void __load_psw_mask(unsigned long mask) { + psw_t psw __uninitialized; unsigned long addr; - psw_t psw; psw.mask = mask;