[deliverable/linux.git] / arch / x86 / lib / putuser.S

/*
 * __put_user functions.
 *
 * (C) Copyright 2005 Linus Torvalds
 * (C) Copyright 2005 Andi Kleen
 * (C) Copyright 2008 Glauber Costa
 *
 * These functions have a non-standard call interface
 * to make them more efficient, especially as they
 * return an error value in addition to the "real"
 * return value.
 */
#include <linux/linkage.h>
#include <asm/thread_info.h>
#include <asm/errno.h>
#include <asm/asm.h>
#include <asm/smap.h>


/*
 * __put_user_X
 *
 * Inputs:	%eax[:%edx] contains the data
 *		%ecx contains the address
 *
 * Outputs:	%eax is error code (0 or -EFAULT)
 *
 * These functions should not modify any other registers,
 * as they get called from within inline assembly.
 */

#define ENTER	mov PER_CPU_VAR(current_task), %_ASM_BX
#define EXIT	ASM_CLAC ;	\
		ret

.text
ENTRY(__put_user_1)
	ENTER
	cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX
	jae bad_put_user
	ASM_STAC
1:	movb %al,(%_ASM_CX)
	xor %eax,%eax
	EXIT
ENDPROC(__put_user_1)

ENTRY(__put_user_2)
	ENTER
	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
	sub $1,%_ASM_BX
	cmp %_ASM_BX,%_ASM_CX
	jae bad_put_user
	ASM_STAC
2:	movw %ax,(%_ASM_CX)
	xor %eax,%eax
	EXIT
ENDPROC(__put_user_2)

ENTRY(__put_user_4)
	ENTER
	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
	sub $3,%_ASM_BX
	cmp %_ASM_BX,%_ASM_CX
	jae bad_put_user
	ASM_STAC
3:	movl %eax,(%_ASM_CX)
	xor %eax,%eax
	EXIT
ENDPROC(__put_user_4)

ENTRY(__put_user_8)
	ENTER
	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
	sub $7,%_ASM_BX
	cmp %_ASM_BX,%_ASM_CX
	jae bad_put_user
	ASM_STAC
4:	mov %_ASM_AX,(%_ASM_CX)
#ifdef CONFIG_X86_32
5:	movl %edx,4(%_ASM_CX)
#endif
	xor %eax,%eax
	EXIT
ENDPROC(__put_user_8)

bad_put_user:
	movl $-EFAULT,%eax
	EXIT
END(bad_put_user)

	_ASM_EXTABLE(1b,bad_put_user)
	_ASM_EXTABLE(2b,bad_put_user)
	_ASM_EXTABLE(3b,bad_put_user)
	_ASM_EXTABLE(4b,bad_put_user)
#ifdef CONFIG_X86_32
	_ASM_EXTABLE(5b,bad_put_user)
#endif
Commit	Line	Data
	1	/*
	2	* __put_user functions.
	3	*
	4	* (C) Copyright 2005 Linus Torvalds
	5	* (C) Copyright 2005 Andi Kleen
	6	* (C) Copyright 2008 Glauber Costa
	7	*
	8	* These functions have a non-standard call interface
	9	* to make them more efficient, especially as they
	10	* return an error value in addition to the "real"
	11	* return value.
	12	*/
	13	#include <linux/linkage.h>
	14	#include <asm/thread_info.h>
	15	#include <asm/errno.h>
	16	#include <asm/asm.h>
	17	#include <asm/smap.h>
	18
	19
	20	/*
	21	* __put_user_X
	22	*
	23	* Inputs: %eax[:%edx] contains the data
	24	* %ecx contains the address
	25	*
	26	* Outputs: %eax is error code (0 or -EFAULT)
	27	*
	28	* These functions should not modify any other registers,
	29	* as they get called from within inline assembly.
	30	*/
	31
	32	#define ENTER mov PER_CPU_VAR(current_task), %_ASM_BX
	33	#define EXIT ASM_CLAC ; \
	34	ret
	35
	36	.text
	37	ENTRY(__put_user_1)
	38	ENTER
	39	cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX
	40	jae bad_put_user
	41	ASM_STAC
	42	1: movb %al,(%_ASM_CX)
	43	xor %eax,%eax
	44	EXIT
	45	ENDPROC(__put_user_1)
	46
	47	ENTRY(__put_user_2)
	48	ENTER
	49	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
	50	sub $1,%_ASM_BX
	51	cmp %_ASM_BX,%_ASM_CX
	52	jae bad_put_user
	53	ASM_STAC
	54	2: movw %ax,(%_ASM_CX)
	55	xor %eax,%eax
	56	EXIT
	57	ENDPROC(__put_user_2)
	58
	59	ENTRY(__put_user_4)
	60	ENTER
	61	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
	62	sub $3,%_ASM_BX
	63	cmp %_ASM_BX,%_ASM_CX
	64	jae bad_put_user
	65	ASM_STAC
	66	3: movl %eax,(%_ASM_CX)
	67	xor %eax,%eax
	68	EXIT
	69	ENDPROC(__put_user_4)
	70
	71	ENTRY(__put_user_8)
	72	ENTER
	73	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
	74	sub $7,%_ASM_BX
	75	cmp %_ASM_BX,%_ASM_CX
	76	jae bad_put_user
	77	ASM_STAC
	78	4: mov %_ASM_AX,(%_ASM_CX)
	79	#ifdef CONFIG_X86_32
	80	5: movl %edx,4(%_ASM_CX)
	81	#endif
	82	xor %eax,%eax
	83	EXIT
	84	ENDPROC(__put_user_8)
	85
	86	bad_put_user:
	87	movl $-EFAULT,%eax
	88	EXIT
	89	END(bad_put_user)
	90
	91	_ASM_EXTABLE(1b,bad_put_user)
	92	_ASM_EXTABLE(2b,bad_put_user)
	93	_ASM_EXTABLE(3b,bad_put_user)
	94	_ASM_EXTABLE(4b,bad_put_user)
	95	#ifdef CONFIG_X86_32
	96	_ASM_EXTABLE(5b,bad_put_user)
	97	#endif