diff options
| author | Glauber Costa <gcosta@redhat.com> | 2008-06-13 16:35:52 -0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-09 09:13:59 +0200 |
| commit | edf10162b2c5ad78ada8e63e960f9d0949c6c219 (patch) | |
| tree | c860cce966d760d230fe56de713093b7eec25df4 | |
| parent | f8dd0d3c62164160c59034a96eb17d69ac8a0328 (diff) | |
x86: don't clobber r8 nor use rcx.
There's really no reason to clobber r8 or pass the address in rcx.
We can safely use only two registers (which we already have to touch anyway)
to do the job.
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>
| -rw-r--r-- | arch/x86/lib/getuser_64.S | 42 | ||||
| -rw-r--r-- | include/asm-x86/uaccess_64.h | 3 |
2 files changed, 22 insertions, 23 deletions
diff --git a/arch/x86/lib/getuser_64.S b/arch/x86/lib/getuser_64.S index 5448876261f..2b003d31348 100644 --- a/arch/x86/lib/getuser_64.S +++ b/arch/x86/lib/getuser_64.S @@ -36,10 +36,10 @@ .text ENTRY(__get_user_1) CFI_STARTPROC - GET_THREAD_INFO(%r8) - cmpq threadinfo_addr_limit(%r8),%rcx + GET_THREAD_INFO(%rdx) + cmpq threadinfo_addr_limit(%rdx),%rax jae bad_get_user -1: movzb (%rcx),%edx +1: movzb (%rax),%edx xorl %eax,%eax ret CFI_ENDPROC @@ -47,48 +47,48 @@ ENDPROC(__get_user_1) ENTRY(__get_user_2) CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $1,%rcx + GET_THREAD_INFO(%rdx) + addq $1,%rax jc 20f - cmpq threadinfo_addr_limit(%r8),%rcx + cmpq threadinfo_addr_limit(%rdx),%rax jae 20f - decq %rcx -2: movzwl (%rcx),%edx + decq %rax +2: movzwl (%rax),%edx xorl %eax,%eax ret -20: decq %rcx +20: decq %rax jmp bad_get_user CFI_ENDPROC ENDPROC(__get_user_2) ENTRY(__get_user_4) CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $3,%rcx + GET_THREAD_INFO(%rdx) + addq $3,%rax jc 30f - cmpq threadinfo_addr_limit(%r8),%rcx + cmpq threadinfo_addr_limit(%rdx),%rax jae 30f - subq $3,%rcx -3: movl (%rcx),%edx + subq $3,%rax +3: movl (%rax),%edx xorl %eax,%eax ret -30: subq $3,%rcx +30: subq $3,%rax jmp bad_get_user CFI_ENDPROC ENDPROC(__get_user_4) ENTRY(__get_user_8) CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $7,%rcx + GET_THREAD_INFO(%rdx) + addq $7,%rax jc 40f - cmpq threadinfo_addr_limit(%r8),%rcx + cmpq threadinfo_addr_limit(%rdx),%rax jae 40f - subq $7,%rcx -4: movq (%rcx),%rdx + subq $7,%rax +4: movq (%rax),%rdx xorl %eax,%eax ret -40: subq $7,%rcx +40: subq $7,%rax jmp bad_get_user CFI_ENDPROC ENDPROC(__get_user_8) diff --git a/include/asm-x86/uaccess_64.h b/include/asm-x86/uaccess_64.h index b8a2f433990..a2d49078e19 100644 --- a/include/asm-x86/uaccess_64.h +++ b/include/asm-x86/uaccess_64.h @@ -90,8 +90,7 @@ extern int fixup_exception(struct pt_regs *regs); #define __get_user_x(size, ret, x, ptr) \ asm volatile("call __get_user_" #size \ : "=a" (ret),"=d" (x) \ - : "c" (ptr) \ - : "r8") + : "0" (ptr)) \ /* Careful: we have to cast the result to the type of the pointer * for sign reasons */ |