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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 18:22:04 +02:00 committed by Greg Kroah-Hartman
parent d7aa3f13e1
commit 0d201ff077
1 changed files with 8 additions and 5 deletions
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13
arch/s390/lib/mem.S
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@ -7,6 +7,9 @@
#include <linux/linkage.h>
#include <asm/export.h>
#include <asm/nospec-insn.h>
GEN_BR_THUNK %r14
/*
* void *memmove(void *dest, const void *src, size_t n)
@ -33,14 +36,14 @@ ENTRY(memmove)
.Lmemmove_forward_remainder:
larl %r5,.Lmemmove_mvc
ex %r4,0(%r5)
br %r14
BR_EX %r14
.Lmemmove_reverse:
ic %r0,0(%r4,%r3)
stc %r0,0(%r4,%r1)
brctg %r4,.Lmemmove_reverse
ic %r0,0(%r4,%r3)
stc %r0,0(%r4,%r1)
br %r14
BR_EX %r14
.Lmemmove_mvc:
mvc 0(1,%r1),0(%r3)
EXPORT_SYMBOL(memmove)
@ -77,7 +80,7 @@ ENTRY(memset)
.Lmemset_clear_remainder:
larl %r3,.Lmemset_xc
ex %r4,0(%r3)
br %r14
BR_EX %r14
.Lmemset_fill:
stc %r3,0(%r2)
cghi %r4,1
@ -94,7 +97,7 @@ ENTRY(memset)
.Lmemset_fill_remainder:
larl %r3,.Lmemset_mvc
ex %r4,0(%r3)
br %r14
BR_EX %r14
.Lmemset_xc:
xc 0(1,%r1),0(%r1)
.Lmemset_mvc:
@ -117,7 +120,7 @@ ENTRY(memcpy)
.Lmemcpy_remainder:
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)