4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sven Schnelle <svens@xxxxxxxxxxxxx>
[ 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 <hca@xxxxxxxxxxxxx>
Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 7f2953c15c37b..93ba3befd6d40 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -289,8 +289,8 @@ static inline void __load_psw(psw_t psw)
*/
static inline void __load_psw_mask(unsigned long mask)
{
+ psw_t psw __uninitialized;
unsigned long addr;
- psw_t psw;
psw.mask = mask;
--
2.43.0
