From 4164ae404d145052e20d5a810ca776dd85f25b8b Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky schwidefsky@de.ibm.com Date: Mon, 6 Aug 2018 13:49:47 +0200 Subject: [PATCH] s390/lib: use expoline for all bcr instructions
[ Upstream commit de481fa3f40d7e46f804f1b19d536b390bda5e59 ]
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 --- arch/s390/lib/mem.S | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/s390/lib/mem.S b/arch/s390/lib/mem.S index e1fa974ac500..37e52118d7e9 100644 --- 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 @@ -80,12 +81,13 @@ ENTRY(memset) .Lmemset_clear_remainder: larl %r3,.Lmemset_xc ex %r4,0(%r3) +.Lmemset_exit: BR_EX %r14 .Lmemset_fill: stc %r3,0(%r2) cghi %r4,1 lgr %r1,%r2 - ber %r14 + je .Lmemset_fill_exit aghi %r4,-2 srlg %r3,%r4,8 ltgr %r3,%r3 @@ -97,6 +99,7 @@ ENTRY(memset) .Lmemset_fill_remainder: larl %r3,.Lmemset_mvc ex %r4,0(%r3) +.Lmemset_fill_exit: BR_EX %r14 .Lmemset_xc: xc 0(1,%r1),0(%r1) @@ -111,7 +114,7 @@ EXPORT_SYMBOL(memset) */ ENTRY(memcpy) ltgr %r4,%r4 - bzr %r14 + jz .Lmemcpy_exit aghi %r4,-1 srlg %r5,%r4,8 ltgr %r5,%r5 @@ -120,6 +123,7 @@ 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)