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authorGlauber Costa <gcosta@redhat.com>2008-06-24 16:51:59 -0300
committerIngo Molnar <mingo@elte.hu>2008-07-09 09:14:09 +0200
commit663aa96df32af9c4141ef3179282f95c7537643a (patch)
treefd8856815bea7ef8b6525f498cbc6f7dc2ded28e /arch/x86/lib
parent0ada3164031162b4e1b7ff6b36ba8cc80ff7fe96 (diff)
x86: change testing logic in putuser_64.S.
Instead of operating over a register we need to put back into normal state afterwards (the memory position), just sub from rbx, which is trashed anyway. We can save a few instructions. Also, this is the i386 way. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/putuser_64.S33
1 files changed, 12 insertions, 21 deletions
diff --git a/arch/x86/lib/putuser_64.S b/arch/x86/lib/putuser_64.S
index ce5fcd5d8c1..a96bd8a5298 100644
--- a/arch/x86/lib/putuser_64.S
+++ b/arch/x86/lib/putuser_64.S
@@ -46,48 +46,39 @@ ENDPROC(__put_user_1)
ENTRY(__put_user_2)
CFI_STARTPROC
GET_THREAD_INFO(%rbx)
- addq $1,%rcx
- jc 20f
- cmpq TI_addr_limit(%rbx),%rcx
- jae 20f
- decq %rcx
+ mov TI_addr_limit(%rbx),%rbx
+ sub $1, %rbx
+ cmpq %rbx ,%rcx
+ jae bad_put_user
2: movw %ax,(%rcx)
xorl %eax,%eax
ret
-20: decq %rcx
- jmp bad_put_user
CFI_ENDPROC
ENDPROC(__put_user_2)
ENTRY(__put_user_4)
CFI_STARTPROC
GET_THREAD_INFO(%rbx)
- addq $3,%rcx
- jc 30f
- cmpq TI_addr_limit(%rbx),%rcx
- jae 30f
- subq $3,%rcx
+ mov TI_addr_limit(%rbx),%rbx
+ sub $3, %rbx
+ cmp %rbx, %rcx
+ jae bad_put_user
3: movl %eax,(%rcx)
xorl %eax,%eax
ret
-30: subq $3,%rcx
- jmp bad_put_user
CFI_ENDPROC
ENDPROC(__put_user_4)
ENTRY(__put_user_8)
CFI_STARTPROC
GET_THREAD_INFO(%rbx)
- addq $7,%rcx
- jc 40f
- cmpq TI_addr_limit(%rbx),%rcx
- jae 40f
- subq $7,%rcx
+ mov TI_addr_limit(%rbx),%rbx
+ sub $7, %rbx
+ cmp %rbx, %rcx
+ jae bad_put_user
4: movq %rax,(%rcx)
xorl %eax,%eax
ret
-40: subq $7,%rcx
- jmp bad_put_user
CFI_ENDPROC
ENDPROC(__put_user_8)