x86: introduce __ASM_REG macro.
There are situations in which the architecture wants to use the
register that represents its word-size, whatever it is. For those,
introduce __ASM_REG in asm.h, along with the first users _ASM_AX
and _ASM_DX. They have users waiting for it, namely the getuser
functions.
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 6134752..63b0e5c 100644
--- a/arch/x86/lib/getuser_64.S
+++ b/arch/x86/lib/getuser_64.S
@@ -13,14 +13,13 @@
/*
* __get_user_X
*
- * Inputs: %rcx contains the address.
+ * Inputs: %rax contains the address.
* The register is modified, but all changes are undone
* before returning because the C code doesn't know about it.
*
* Outputs: %rax is error code (0 or -EFAULT)
* %rdx contains zero-extended value
*
- * %r8 is destroyed.
*
* These functions should not modify any other registers,
* as they get called from within inline assembly.
@@ -32,14 +31,15 @@
#include <asm/errno.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
+#include <asm/asm.h>
.text
ENTRY(__get_user_1)
CFI_STARTPROC
- GET_THREAD_INFO(%rdx)
- cmp TI_addr_limit(%rdx),%rax
+ GET_THREAD_INFO(%_ASM_DX)
+ cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
jae bad_get_user
-1: movzb (%rax),%edx
+1: movzb (%_ASM_AX),%edx
xor %eax,%eax
ret
CFI_ENDPROC
@@ -47,12 +47,12 @@
ENTRY(__get_user_2)
CFI_STARTPROC
- add $1,%rax
+ add $1,%_ASM_AX
jc bad_get_user
- GET_THREAD_INFO(%rdx)
- cmp TI_addr_limit(%rdx),%rax
+ GET_THREAD_INFO(%_ASM_DX)
+ cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
jae bad_get_user
-2: movzwl -1(%rax),%edx
+2: movzwl -1(%_ASM_AX),%edx
xor %eax,%eax
ret
CFI_ENDPROC
@@ -60,12 +60,12 @@
ENTRY(__get_user_4)
CFI_STARTPROC
- add $3,%rax
+ add $3,%_ASM_AX
jc bad_get_user
- GET_THREAD_INFO(%rdx)
- cmp TI_addr_limit(%rdx),%rax
+ GET_THREAD_INFO(%_ASM_DX)
+ cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
jae bad_get_user
-3: mov -3(%rax),%edx
+3: mov -3(%_ASM_AX),%edx
xor %eax,%eax
ret
CFI_ENDPROC
@@ -73,12 +73,12 @@
ENTRY(__get_user_8)
CFI_STARTPROC
- add $7,%rax
+ add $7,%_ASM_AX
jc bad_get_user
- GET_THREAD_INFO(%rdx)
- cmp TI_addr_limit(%rdx),%rax
+ GET_THREAD_INFO(%_ASM_DX)
+ cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
jae bad_get_user
-4: movq -7(%rax),%rdx
+4: movq -7(%_ASM_AX),%_ASM_DX
xor %eax,%eax
ret
CFI_ENDPROC
@@ -87,7 +87,7 @@
bad_get_user:
CFI_STARTPROC
xor %edx,%edx
- mov $(-EFAULT),%rax
+ mov $(-EFAULT),%_ASM_AX
ret
CFI_ENDPROC
END(bad_get_user)