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/page_types.h>
 30#include <asm/errno.h>
 31#include <asm/asm-offsets.h>
 32#include <asm/thread_info.h>
 33#include <asm/asm.h>
 34#include <asm/smap.h>
 35#include <asm/export.h>
 36
 37	.text
 38ENTRY(__get_user_1)
 39	mov PER_CPU_VAR(current_task), %_ASM_DX
 40	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 
 41	jae bad_get_user
 42	ASM_STAC
 431:	movzbl (%_ASM_AX),%edx
 44	xor %eax,%eax
 45	ASM_CLAC
 46	ret
 
 47ENDPROC(__get_user_1)
 48EXPORT_SYMBOL(__get_user_1)
 49
 50ENTRY(__get_user_2)
 
 51	add $1,%_ASM_AX
 52	jc bad_get_user
 53	mov PER_CPU_VAR(current_task), %_ASM_DX
 54	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 55	jae bad_get_user
 56	ASM_STAC
 572:	movzwl -1(%_ASM_AX),%edx
 58	xor %eax,%eax
 59	ASM_CLAC
 60	ret
 
 61ENDPROC(__get_user_2)
 62EXPORT_SYMBOL(__get_user_2)
 63
 64ENTRY(__get_user_4)
 
 65	add $3,%_ASM_AX
 66	jc bad_get_user
 67	mov PER_CPU_VAR(current_task), %_ASM_DX
 68	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 69	jae bad_get_user
 70	ASM_STAC
 713:	movl -3(%_ASM_AX),%edx
 72	xor %eax,%eax
 73	ASM_CLAC
 74	ret
 
 75ENDPROC(__get_user_4)
 76EXPORT_SYMBOL(__get_user_4)
 77
 78ENTRY(__get_user_8)
 79#ifdef CONFIG_X86_64
 
 
 80	add $7,%_ASM_AX
 81	jc bad_get_user
 82	mov PER_CPU_VAR(current_task), %_ASM_DX
 83	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 84	jae bad_get_user
 85	ASM_STAC
 864:	movq -7(%_ASM_AX),%rdx
 87	xor %eax,%eax
 88	ASM_CLAC
 89	ret
 90#else
 91	add $7,%_ASM_AX
 92	jc bad_get_user_8
 93	mov PER_CPU_VAR(current_task), %_ASM_DX
 94	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 95	jae bad_get_user_8
 96	ASM_STAC
 974:	movl -7(%_ASM_AX),%edx
 985:	movl -3(%_ASM_AX),%ecx
 99	xor %eax,%eax
100	ASM_CLAC
101	ret
102#endif
103ENDPROC(__get_user_8)
104EXPORT_SYMBOL(__get_user_8)
105
106
107bad_get_user:
 
108	xor %edx,%edx
109	mov $(-EFAULT),%_ASM_AX
110	ASM_CLAC
111	ret
 
112END(bad_get_user)
113
114#ifdef CONFIG_X86_32
115bad_get_user_8:
116	xor %edx,%edx
117	xor %ecx,%ecx
118	mov $(-EFAULT),%_ASM_AX
119	ASM_CLAC
120	ret
121END(bad_get_user_8)
122#endif
123
124	_ASM_EXTABLE(1b,bad_get_user)
125	_ASM_EXTABLE(2b,bad_get_user)
126	_ASM_EXTABLE(3b,bad_get_user)
127#ifdef CONFIG_X86_64
128	_ASM_EXTABLE(4b,bad_get_user)
129#else
130	_ASM_EXTABLE(4b,bad_get_user_8)
131	_ASM_EXTABLE(5b,bad_get_user_8)
132#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 *		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