Commit 97489e06 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/lib: use expoline for indirect branches 



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: f19fbd5e ("s390: introduce execute-trampolines for branches")
Reviewed-by: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 467a3bf2

arch/s390/lib/mem.S

+11 −8
Original line number Diff line number Diff line
@@ -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:

	cghi	%r4,1

	lgr	%r1,%r2
@@ -95,10 +98,10 @@ ENTRY(memset) 
	stc	%r3,0(%r1)

	larl	%r5,.Lmemset_mvc

	ex	%r4,0(%r5)

	br	%r14

	BR_EX	%r14

.Lmemset_fill_exit:

	stc	%r3,0(%r1)

	br	%r14

	BR_EX	%r14

.Lmemset_xc:

	xc	0(1,%r1),0(%r1)

.Lmemset_mvc:
@@ -121,7 +124,7 @@ 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)
@@ -159,10 +162,10 @@ ENTRY(__memset\bits) 
	\insn	%r3,0(%r1)

	larl	%r5,.L__memset_mvc\bits

	ex	%r4,0(%r5)

	br	%r14

	BR_EX	%r14

.L__memset_exit\bits:

	\insn	%r3,0(%r2)

	br	%r14

	BR_EX	%r14

.L__memset_mvc\bits:

	mvc	\bytes(1,%r1),0(%r1)

.endm

CRA Git | Maintained and supported by SUSTech CRA and CCSE