1/*
  2 * __get_user functions.
  3 *
  4 * (C) Copyright 1998 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
 14/*
 15 * __get_user_X
 16 *
 17 * Inputs:	%[r|e]ax contains the address.
 18 *		The register is modified, but all changes are undone
 19 *		before returning because the C code doesn't know about it.
 20 *
 21 * Outputs:	%[r|e]ax is error code (0 or -EFAULT)
 22 *		%[r|e]dx contains zero-extended value
 
 23 *
 24 *
 25 * These functions should not modify any other registers,
 26 * as they get called from within inline assembly.
 27 */
 28
 29#include <linux/linkage.h>
 30#include <asm/dwarf2.h>
 31#include <asm/page_types.h>
 32#include <asm/errno.h>
 33#include <asm/asm-offsets.h>
 34#include <asm/thread_info.h>
 35#include <asm/asm.h>
 
 36
 37	.text
 38ENTRY(__get_user_1)
 39	CFI_STARTPROC
 40	GET_THREAD_INFO(%_ASM_DX)
 41	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 42	jae bad_get_user
 431:	movzb (%_ASM_AX),%edx
 
 44	xor %eax,%eax
 
 45	ret
 46	CFI_ENDPROC
 47ENDPROC(__get_user_1)
 48
 49ENTRY(__get_user_2)
 50	CFI_STARTPROC
 51	add $1,%_ASM_AX
 52	jc bad_get_user
 53	GET_THREAD_INFO(%_ASM_DX)
 54	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 55	jae bad_get_user
 
 562:	movzwl -1(%_ASM_AX),%edx
 57	xor %eax,%eax
 
 58	ret
 59	CFI_ENDPROC
 60ENDPROC(__get_user_2)
 61
 62ENTRY(__get_user_4)
 63	CFI_STARTPROC
 64	add $3,%_ASM_AX
 65	jc bad_get_user
 66	GET_THREAD_INFO(%_ASM_DX)
 67	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 68	jae bad_get_user
 693:	mov -3(%_ASM_AX),%edx
 
 70	xor %eax,%eax
 
 71	ret
 72	CFI_ENDPROC
 73ENDPROC(__get_user_4)
 74
 75#ifdef CONFIG_X86_64
 76ENTRY(__get_user_8)
 77	CFI_STARTPROC
 
 78	add $7,%_ASM_AX
 79	jc bad_get_user
 80	GET_THREAD_INFO(%_ASM_DX)
 81	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 82	jae	bad_get_user
 834:	movq -7(%_ASM_AX),%_ASM_DX
 
 84	xor %eax,%eax
 
 85	ret
 
 
 
 
 
 
 
 
 
 
 
 
 
 86	CFI_ENDPROC
 87ENDPROC(__get_user_8)
 88#endif
 89
 90bad_get_user:
 91	CFI_STARTPROC
 92	xor %edx,%edx
 93	mov $(-EFAULT),%_ASM_AX
 
 94	ret
 95	CFI_ENDPROC
 96END(bad_get_user)
 97
 
 
 
 
 
 
 
 
 
 
 
 
 98	_ASM_EXTABLE(1b,bad_get_user)
 99	_ASM_EXTABLE(2b,bad_get_user)
100	_ASM_EXTABLE(3b,bad_get_user)
101#ifdef CONFIG_X86_64
102	_ASM_EXTABLE(4b,bad_get_user)
 
 
 
103#endif

  1/*
  2 * __get_user functions.
  3 *
  4 * (C) Copyright 1998 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
 14/*
 15 * __get_user_X
 16 *
 17 * Inputs:	%[r|e]ax contains the address.
 
 
 18 *
 19 * Outputs:	%[r|e]ax is error code (0 or -EFAULT)
 20 *		%[r|e]dx contains zero-extended value
 21 *		%ecx contains the high half for 32-bit __get_user_8
 22 *
 23 *
 24 * These functions should not modify any other registers,
 25 * as they get called from within inline assembly.
 26 */
 27
 28#include <linux/linkage.h>
 29#include <asm/dwarf2.h>
 30#include <asm/page_types.h>
 31#include <asm/errno.h>
 32#include <asm/asm-offsets.h>
 33#include <asm/thread_info.h>
 34#include <asm/asm.h>
 35#include <asm/smap.h>
 36
 37	.text
 38ENTRY(__get_user_1)
 39	CFI_STARTPROC
 40	GET_THREAD_INFO(%_ASM_DX)
 41	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 42	jae bad_get_user
 43	ASM_STAC
 441:	movzbl (%_ASM_AX),%edx
 45	xor %eax,%eax
 46	ASM_CLAC
 47	ret
 48	CFI_ENDPROC
 49ENDPROC(__get_user_1)
 50
 51ENTRY(__get_user_2)
 52	CFI_STARTPROC
 53	add $1,%_ASM_AX
 54	jc bad_get_user
 55	GET_THREAD_INFO(%_ASM_DX)
 56	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 57	jae bad_get_user
 58	ASM_STAC
 592:	movzwl -1(%_ASM_AX),%edx
 60	xor %eax,%eax
 61	ASM_CLAC
 62	ret
 63	CFI_ENDPROC
 64ENDPROC(__get_user_2)
 65
 66ENTRY(__get_user_4)
 67	CFI_STARTPROC
 68	add $3,%_ASM_AX
 69	jc bad_get_user
 70	GET_THREAD_INFO(%_ASM_DX)
 71	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 72	jae bad_get_user
 73	ASM_STAC
 743:	movl -3(%_ASM_AX),%edx
 75	xor %eax,%eax
 76	ASM_CLAC
 77	ret
 78	CFI_ENDPROC
 79ENDPROC(__get_user_4)
 80
 
 81ENTRY(__get_user_8)
 82	CFI_STARTPROC
 83#ifdef CONFIG_X86_64
 84	add $7,%_ASM_AX
 85	jc bad_get_user
 86	GET_THREAD_INFO(%_ASM_DX)
 87	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 88	jae bad_get_user
 89	ASM_STAC
 904:	movq -7(%_ASM_AX),%rdx
 91	xor %eax,%eax
 92	ASM_CLAC
 93	ret
 94#else
 95	add $7,%_ASM_AX
 96	jc bad_get_user_8
 97	GET_THREAD_INFO(%_ASM_DX)
 98	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
 99	jae bad_get_user_8
100	ASM_STAC
1014:	movl -7(%_ASM_AX),%edx
1025:	movl -3(%_ASM_AX),%ecx
103	xor %eax,%eax
104	ASM_CLAC
105	ret
106#endif
107	CFI_ENDPROC
108ENDPROC(__get_user_8)
109
110
111bad_get_user:
112	CFI_STARTPROC
113	xor %edx,%edx
114	mov $(-EFAULT),%_ASM_AX
115	ASM_CLAC
116	ret
117	CFI_ENDPROC
118END(bad_get_user)
119
120#ifdef CONFIG_X86_32
121bad_get_user_8:
122	CFI_STARTPROC
123	xor %edx,%edx
124	xor %ecx,%ecx
125	mov $(-EFAULT),%_ASM_AX
126	ASM_CLAC
127	ret
128	CFI_ENDPROC
129END(bad_get_user_8)
130#endif
131
132	_ASM_EXTABLE(1b,bad_get_user)
133	_ASM_EXTABLE(2b,bad_get_user)
134	_ASM_EXTABLE(3b,bad_get_user)
135#ifdef CONFIG_X86_64
136	_ASM_EXTABLE(4b,bad_get_user)
137#else
138	_ASM_EXTABLE(4b,bad_get_user_8)
139	_ASM_EXTABLE(5b,bad_get_user_8)
140#endif