x86: adapt x86_64 getuser functions.

Instead of doing a sub after the addition, use the
offset directly at the memory operand of the mov instructions.
This is the way i386 do.

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>

diff --git a/arch/x86/lib/getuser_64.S b/arch/x86/lib/getuser_64.S
index 2b003d3..df37d3a 100644 (file)
--- a/arch/x86/lib/getuser_64.S
+++ b/arch/x86/lib/getuser_64.S
@@ -47,49 +47,40 @@ ENDPROC(__get_user_1)
 
 ENTRY(__get_user_2)
        CFI_STARTPROC
-       GET_THREAD_INFO(%rdx)
        addq $1,%rax
-       jc 20f
+       jc bad_get_user
+       GET_THREAD_INFO(%rdx)
        cmpq threadinfo_addr_limit(%rdx),%rax
-       jae 20f
-       decq   %rax
-2:     movzwl (%rax),%edx
+       jae bad_get_user
+2:     movzwl -1(%rax),%edx
        xorl %eax,%eax
        ret
-20:    decq    %rax
-       jmp     bad_get_user
        CFI_ENDPROC
 ENDPROC(__get_user_2)
 
 ENTRY(__get_user_4)
        CFI_STARTPROC
-       GET_THREAD_INFO(%rdx)
        addq $3,%rax
-       jc 30f
+       jc bad_get_user
+       GET_THREAD_INFO(%rdx)
        cmpq threadinfo_addr_limit(%rdx),%rax
-       jae 30f
-       subq $3,%rax
-3:     movl (%rax),%edx
+       jae bad_get_user
+3:     movl -3(%rax),%edx
        xorl %eax,%eax
        ret
-30:    subq $3,%rax
-       jmp bad_get_user
        CFI_ENDPROC
 ENDPROC(__get_user_4)
 
 ENTRY(__get_user_8)
        CFI_STARTPROC
-       GET_THREAD_INFO(%rdx)
        addq $7,%rax
-       jc 40f
+       jc bad_get_user
+       GET_THREAD_INFO(%rdx)
        cmpq threadinfo_addr_limit(%rdx),%rax
-       jae     40f
-       subq    $7,%rax
-4:     movq (%rax),%rdx
+       jae     bad_get_user
+4:     movq -7(%rax),%rdx
        xorl %eax,%eax
        ret
-40:    subq $7,%rax
-       jmp bad_get_user
        CFI_ENDPROC
 ENDPROC(__get_user_8)