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s390/lib: use expoline for indirect branches

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[ 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@vger.kernel.org # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Martin Schwidefsky 2018-05-23 18:21:47 +02:00 committed by Greg Kroah-Hartman
parent f37bfc0d20
commit cba0d6c2d6
1 changed files with 6 additions and 3 deletions
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9
arch/s390/lib/mem.S
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@ -6,6 +6,9 @@
#include <linux/linkage.h>
#include <asm/export.h>
#include <asm/nospec-insn.h>
GEN_BR_THUNK %r14
/*
* memset implementation
@ -39,7 +42,7 @@ 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
@ -56,7 +59,7 @@ 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:
@ -79,7 +82,7 @@ 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)