From 52c0b3cb6f031dd2ad69eb45a552e3d8563aaa16 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Wed, 8 Jan 2025 15:27:02 +0100 Subject: [PATCH] s390/stackleak: Use exrl instead of ex in __stackleak_poison() [ Upstream commit a88c26bb8e04ee5f2678225c0130a5fbc08eef85 ] exrl is present in all machines currently supported, therefore prefer it over ex. This saves one instruction and doesn't need an additional register to hold the address of the target instruction. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin --- arch/s390/include/asm/processor.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index e7338ed540d8..2f373e8cfed3 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -140,8 +140,7 @@ static __always_inline void __stackleak_poison(unsigned long erase_low, " la %[addr],256(%[addr])\n" " brctg %[tmp],0b\n" "1: stg %[poison],0(%[addr])\n" - " larl %[tmp],3f\n" - " ex %[count],0(%[tmp])\n" + " exrl %[count],3f\n" " j 4f\n" "2: stg %[poison],0(%[addr])\n" " j 4f\n"