Author: mjg
Date: Sun Sep 16 21:46:27 2018
New Revision: 338702
URL: https://svnweb.freebsd.org/changeset/base/338702
Log:
Revert amd64: tidy up kernel memmove
There is a braino in the non-erms variant which breaks the
functionality.
Will be fixed at a later time with a different patch.
Reported by: Manfred Antar
Approved by: re (implicit)
Modified:
head/sys/amd64/amd64/support.S
Modified: head/sys/amd64/amd64/support.S
==============================================================================
--- head/sys/amd64/amd64/support.S Sun Sep 16 21:44:36 2018
(r338701)
+++ head/sys/amd64/amd64/support.S Sun Sep 16 21:46:27 2018
(r338702)
@@ -108,12 +108,12 @@ END(sse2_pagezero)
*/
ENTRY(memmove_std)
PUSH_FRAME_POINTER
- movq %rdi,%rax
+ movq %rdi,%r9
movq %rdx,%rcx
- movq %rdi,%r8
- subq %rsi,%r8
- cmpq %rcx,%r8 /* overlapping && src < dst? */
+ movq %rdi,%rax
+ subq %rsi,%rax
+ cmpq %rcx,%rax /* overlapping && src < dst? */
jb 1f
shrq $3,%rcx /* copy by 64-bit words */
@@ -128,6 +128,7 @@ ENTRY(memmove_std)
2:
rep
movsb
+ movq %r9,%rax
POP_FRAME_POINTER
ret
@@ -139,10 +140,8 @@ ENTRY(memmove_std)
decq %rsi
andq $7,%rcx /* any fractional bytes? */
std
- jne 3f
rep
movsb
-3:
movq %rdx,%rcx /* copy remainder by 32-bit
words */
shrq $3,%rcx
subq $7,%rsi
@@ -150,22 +149,24 @@ ENTRY(memmove_std)
rep
movsq
cld
+ movq %r9,%rax
POP_FRAME_POINTER
ret
END(memmove_std)
ENTRY(memmove_erms)
PUSH_FRAME_POINTER
- movq %rdi,%rax
+ movq %rdi,%r9
movq %rdx,%rcx
- movq %rdi,%r8
- subq %rsi,%r8
- cmpq %rcx,%r8 /* overlapping && src < dst? */
+ movq %rdi,%rax
+ subq %rsi,%rax
+ cmpq %rcx,%rax /* overlapping && src < dst? */
jb 1f
rep
movsb
+ movq %r9,%rax
POP_FRAME_POINTER
ret
@@ -178,6 +179,7 @@ ENTRY(memmove_erms)
rep
movsb
cld
+ movq %r9,%rax
POP_FRAME_POINTER
ret
END(memmove_erms)
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