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Subject[PATCH 4.18 088/123] s390/lib: use expoline for all bcr instructions
Date
4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

commit 5eda25b10297684c1f46a14199ec00210f3c346e upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/s390/lib/mem.S | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

--- a/arch/s390/lib/mem.S
+++ b/arch/s390/lib/mem.S
@@ -17,7 +17,7 @@
ENTRY(memmove)
ltgr %r4,%r4
lgr %r1,%r2
- bzr %r14
+ jz .Lmemmove_exit
aghi %r4,-1
clgr %r2,%r3
jnh .Lmemmove_forward
@@ -36,6 +36,7 @@ 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)
@@ -65,7 +66,7 @@ EXPORT_SYMBOL(memmove)
*/
ENTRY(memset)
ltgr %r4,%r4
- bzr %r14
+ jz .Lmemset_exit
ltgr %r3,%r3
jnz .Lmemset_fill
aghi %r4,-1
@@ -80,6 +81,7 @@ ENTRY(memset)
.Lmemset_clear_remainder:
larl %r3,.Lmemset_xc
ex %r4,0(%r3)
+.Lmemset_exit:
BR_EX %r14
.Lmemset_fill:
cghi %r4,1
@@ -115,7 +117,7 @@ EXPORT_SYMBOL(memset)
*/
ENTRY(memcpy)
ltgr %r4,%r4
- bzr %r14
+ jz .Lmemcpy_exit
aghi %r4,-1
srlg %r5,%r4,8
ltgr %r5,%r5
@@ -124,6 +126,7 @@ 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)
@@ -145,9 +148,9 @@ EXPORT_SYMBOL(memcpy)
.macro __MEMSET bits,bytes,insn
ENTRY(__memset\bits)
ltgr %r4,%r4
- bzr %r14
+ jz .L__memset_exit\bits
cghi %r4,\bytes
- je .L__memset_exit\bits
+ je .L__memset_store\bits
aghi %r4,-(\bytes+1)
srlg %r5,%r4,8
ltgr %r5,%r5
@@ -163,8 +166,9 @@ ENTRY(__memset\bits)
larl %r5,.L__memset_mvc\bits
ex %r4,0(%r5)
BR_EX %r14
-.L__memset_exit\bits:
+.L__memset_store\bits:
\insn %r3,0(%r2)
+.L__memset_exit\bits:
BR_EX %r14
.L__memset_mvc\bits:
mvc \bytes(1,%r1),0(%r1)

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