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Commit 40faf463 authored by Glauber Costa's avatar Glauber Costa Committed by Ingo Molnar
Browse files

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: default avatarGlauber Costa <gcosta@redhat.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ef8c1a2d

arch/x86/lib/getuser_32.S

+13 −12
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/linkage.h>

#include <asm/dwarf2.h>

#include <asm/thread_info.h>

#include <asm/asm.h>





/*
@@ -28,10 +29,10 @@ 
.text

ENTRY(__get_user_1)

	CFI_STARTPROC

	GET_THREAD_INFO(%edx)

	cmp TI_addr_limit(%edx),%eax

	GET_THREAD_INFO(%_ASM_DX)

	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX

	jae bad_get_user

1:	movzb (%eax),%edx

1:	movzb (%_ASM_AX),%edx

	xor %eax,%eax

	ret

	CFI_ENDPROC
@@ -39,12 +40,12 @@ ENDPROC(__get_user_1) 


ENTRY(__get_user_2)

	CFI_STARTPROC

	add $1,%eax

	add $1,%_ASM_AX

	jc bad_get_user

	GET_THREAD_INFO(%edx)

	cmp TI_addr_limit(%edx),%eax

	GET_THREAD_INFO(%_ASM_DX)

	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX

	jae bad_get_user

2:	movzwl -1(%eax),%edx

2:	movzwl -1(%_ASM_AX),%edx

	xor %eax,%eax

	ret

	CFI_ENDPROC
@@ -52,12 +53,12 @@ ENDPROC(__get_user_2) 


ENTRY(__get_user_4)

	CFI_STARTPROC

	add $3,%eax

	add $3,%_ASM_AX

	jc bad_get_user

	GET_THREAD_INFO(%edx)

	cmp TI_addr_limit(%edx),%eax

	GET_THREAD_INFO(%_ASM_DX)

	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX

	jae bad_get_user

3:	mov -3(%eax),%edx

3:	mov -3(%_ASM_AX),%edx

	xor %eax,%eax

	ret

	CFI_ENDPROC
@@ -66,7 +67,7 @@ ENDPROC(__get_user_4) 
bad_get_user:

	CFI_STARTPROC

	xor %edx,%edx

	mov $-14,%eax

	mov $-14,%_ASM_AX

	ret

	CFI_ENDPROC

END(bad_get_user)

arch/x86/lib/getuser_64.S

+18 −18
Original line number Diff line number Diff line
@@ -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 @@ ENDPROC(__get_user_1) 


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 @@ ENDPROC(__get_user_2) 


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 @@ ENDPROC(__get_user_4) 


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 @@ ENDPROC(__get_user_8) 
bad_get_user:

	CFI_STARTPROC

	xor %edx,%edx

	mov $(-EFAULT),%rax

	mov $(-EFAULT),%_ASM_AX

	ret

	CFI_ENDPROC

END(bad_get_user)

include/asm-x86/asm.h

+3 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#endif



#define __ASM_SIZE(inst)	__ASM_SEL(inst##l, inst##q)

#define __ASM_REG(reg)		__ASM_SEL(e##reg, r##reg)



#define _ASM_PTR	__ASM_SEL(.long, .quad)

#define _ASM_ALIGN	__ASM_SEL(.balign 4, .balign 8)
@@ -24,6 +25,8 @@ 
#define _ASM_ADD	__ASM_SIZE(add)

#define _ASM_SUB	__ASM_SIZE(sub)

#define _ASM_XADD	__ASM_SIZE(xadd)

#define _ASM_AX		__ASM_REG(ax)

#define _ASM_DX		__ASM_REG(dx)



/* Exception table entry */

# define _ASM_EXTABLE(from,to) \