4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
[ Upstream commit 97489e0663fa700d6e7febddc43b58df98d7bcda ]
The return from the memmove, memset, memcpy, __memset16, __memset32 and
__memset64 functions are done with "br %r14". These are indirect branches
as well and need to use execute trampolines for CONFIG_EXPOLINE=y.
Cc: stable@xxxxxxxxxxxxxxx # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Reviewed-by: Hendrik Brueckner <brueckner@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -5,6 +5,9 @@
*/
#include <linux/linkage.h>
+#include <asm/nospec-insn.h>
+
+ GEN_BR_THUNK %r14
/*
* memset implementation
@@ -38,7 +41,7 @@ ENTRY(memset)
.Lmemset_clear_rest:
larl %r3,.Lmemset_xc
ex %r4,0(%r3)
- br %r14
+ BR_EX %r14
.Lmemset_fill:
stc %r3,0(%r2)
cghi %r4,1
@@ -55,7 +58,7 @@ ENTRY(memset)
.Lmemset_fill_rest:
larl %r3,.Lmemset_mvc
ex %r4,0(%r3)
- br %r14
+ BR_EX %r14
.Lmemset_xc:
xc 0(1,%r1),0(%r1)
.Lmemset_mvc:
@@ -77,7 +80,7 @@ ENTRY(memcpy)
.Lmemcpy_rest:
larl %r5,.Lmemcpy_mvc
ex %r4,0(%r5)
- br %r14
+ BR_EX %r14
.Lmemcpy_loop:
mvc 0(256,%r1),0(%r3)
la %r1,256(%r1)
