From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Mon, 6 Aug 2018 13:49:47 +0200
Subject: s390/lib: use expoline for all bcr instructions
References: git-fixes, bsc#1103421
Git-commit: 5eda25b10297684c1f46a14199ec00210f3c346e
Patch-mainline: v4.19-rc1
The memove, memset, memcpy, __memset16, __memset32 and __memset64
function have an additional indirect return branch in form of a
"bzr" instruction. These need to use expolines as well.
Cc: <stable@vger.kernel.org> # v4.17+
Fixes: 97489e0663 ("s390/lib: use expoline for indirect branches")
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
arch/s390/lib/mem.S | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
--- a/arch/s390/lib/mem.S
+++ b/arch/s390/lib/mem.S
@@ -16,7 +16,7 @@
ENTRY(memmove)
ltgr %r4,%r4
lgr %r1,%r2
- bzr %r14
+ jz .Lmemmove_exit
aghi %r4,-1
clgr %r2,%r3
jnh .Lmemmove_forward
@@ -35,6 +35,7 @@ ENTRY(memmove)
.Lmemmove_forward_remainder:
larl %r5,.Lmemmove_mvc
ex %r4,0(%r5)
+.Lmemmove_exit:
BR_EX %r14
.Lmemmove_reverse:
ic %r0,0(%r4,%r3)
@@ -64,7 +65,7 @@ EXPORT_SYMBOL(memmove)
*/
ENTRY(memset)
ltgr %r4,%r4
- bzr %r14
+ jz .Lmemset_exit
ltgr %r3,%r3
jnz .Lmemset_fill
aghi %r4,-1
@@ -79,6 +80,7 @@ ENTRY(memset)
.Lmemset_clear_remainder:
larl %r3,.Lmemset_xc
ex %r4,0(%r3)
+.Lmemset_exit:
BR_EX %r14
.Lmemset_fill:
cghi %r4,1
@@ -114,7 +116,7 @@ EXPORT_SYMBOL(memset)
*/
ENTRY(memcpy)
ltgr %r4,%r4
- bzr %r14
+ jz .Lmemcpy_exit
aghi %r4,-1
srlg %r5,%r4,8
ltgr %r5,%r5
@@ -123,6 +125,7 @@ ENTRY(memcpy)
.Lmemcpy_remainder:
larl %r5,.Lmemcpy_mvc
ex %r4,0(%r5)
+.Lmemcpy_exit:
BR_EX %r14
.Lmemcpy_loop:
mvc 0(256,%r1),0(%r3)