Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/x86/lib/putuser.S
26424 views
1
/* SPDX-License-Identifier: GPL-2.0 */

2
/*

3
 * __put_user functions.

4
 *

5
 * (C) Copyright 2005 Linus Torvalds

6
 * (C) Copyright 2005 Andi Kleen

7
 * (C) Copyright 2008 Glauber Costa

8
 *

9
 * These functions have a non-standard call interface

10
 * to make them more efficient, especially as they

11
 * return an error value in addition to the "real"

12
 * return value.

13
 */

14
#include <linux/export.h>

15
#include <linux/linkage.h>

16
#include <linux/objtool.h>

17
#include <asm/thread_info.h>

18
#include <asm/errno.h>

19
#include <asm/asm.h>

20
#include <asm/smap.h>

21


22
/*

23
 * __put_user_X

24
 *

25
 * Inputs:	%eax[:%edx] contains the data

26
 *		%ecx contains the address

27
 *

28
 * Outputs:	%ecx is error code (0 or -EFAULT)

29
 *

30
 * Clobbers:	%ebx needed for task pointer

31
 *

32
 * These functions should not modify any other registers,

33
 * as they get called from within inline assembly.

34
 */

35


36
.macro check_range size:req

37
.if IS_ENABLED(CONFIG_X86_64)

38
	mov %rcx, %rbx

39
	sar $63, %rbx

40
	or %rbx, %rcx

41
.else

42
	cmp $TASK_SIZE_MAX-\size+1, %ecx

43
	jae .Lbad_put_user

44
.endif

45
.endm

46


47
.text

48
SYM_FUNC_START(__put_user_1)

49
	ANNOTATE_NOENDBR

50
	check_range size=1

51
	ASM_STAC

52
1:	movb %al,(%_ASM_CX)

53
	xor %ecx,%ecx

54
	ASM_CLAC

55
	RET

56
SYM_FUNC_END(__put_user_1)

57
EXPORT_SYMBOL(__put_user_1)

58


59
SYM_FUNC_START(__put_user_nocheck_1)

60
	ANNOTATE_NOENDBR

61
	ASM_STAC

62
2:	movb %al,(%_ASM_CX)

63
	xor %ecx,%ecx

64
	ASM_CLAC

65
	RET

66
SYM_FUNC_END(__put_user_nocheck_1)

67
EXPORT_SYMBOL(__put_user_nocheck_1)

68


69
SYM_FUNC_START(__put_user_2)

70
	ANNOTATE_NOENDBR

71
	check_range size=2

72
	ASM_STAC

73
3:	movw %ax,(%_ASM_CX)

74
	xor %ecx,%ecx

75
	ASM_CLAC

76
	RET

77
SYM_FUNC_END(__put_user_2)

78
EXPORT_SYMBOL(__put_user_2)

79


80
SYM_FUNC_START(__put_user_nocheck_2)

81
	ANNOTATE_NOENDBR

82
	ASM_STAC

83
4:	movw %ax,(%_ASM_CX)

84
	xor %ecx,%ecx

85
	ASM_CLAC

86
	RET

87
SYM_FUNC_END(__put_user_nocheck_2)

88
EXPORT_SYMBOL(__put_user_nocheck_2)

89


90
SYM_FUNC_START(__put_user_4)

91
	ANNOTATE_NOENDBR

92
	check_range size=4

93
	ASM_STAC

94
5:	movl %eax,(%_ASM_CX)

95
	xor %ecx,%ecx

96
	ASM_CLAC

97
	RET

98
SYM_FUNC_END(__put_user_4)

99
EXPORT_SYMBOL(__put_user_4)

100


101
SYM_FUNC_START(__put_user_nocheck_4)

102
	ANNOTATE_NOENDBR

103
	ASM_STAC

104
6:	movl %eax,(%_ASM_CX)

105
	xor %ecx,%ecx

106
	ASM_CLAC

107
	RET

108
SYM_FUNC_END(__put_user_nocheck_4)

109
EXPORT_SYMBOL(__put_user_nocheck_4)

110


111
SYM_FUNC_START(__put_user_8)

112
	ANNOTATE_NOENDBR

113
	check_range size=8

114
	ASM_STAC

115
7:	mov %_ASM_AX,(%_ASM_CX)

116
#ifdef CONFIG_X86_32

117
8:	movl %edx,4(%_ASM_CX)

118
#endif

119
	xor %ecx,%ecx

120
	ASM_CLAC

121
	RET

122
SYM_FUNC_END(__put_user_8)

123
EXPORT_SYMBOL(__put_user_8)

124


125
SYM_FUNC_START(__put_user_nocheck_8)

126
	ANNOTATE_NOENDBR

127
	ASM_STAC

128
9:	mov %_ASM_AX,(%_ASM_CX)

129
#ifdef CONFIG_X86_32

130
10:	movl %edx,4(%_ASM_CX)

131
#endif

132
	xor %ecx,%ecx

133
	ASM_CLAC

134
	RET

135
SYM_FUNC_END(__put_user_nocheck_8)

136
EXPORT_SYMBOL(__put_user_nocheck_8)

137


138
SYM_CODE_START_LOCAL(__put_user_handle_exception)

139
	ASM_CLAC

140
.Lbad_put_user:

141
	movl $-EFAULT,%ecx

142
	RET

143
SYM_CODE_END(__put_user_handle_exception)

144


145
	_ASM_EXTABLE_UA(1b, __put_user_handle_exception)

146
	_ASM_EXTABLE_UA(2b, __put_user_handle_exception)

147
	_ASM_EXTABLE_UA(3b, __put_user_handle_exception)

148
	_ASM_EXTABLE_UA(4b, __put_user_handle_exception)

149
	_ASM_EXTABLE_UA(5b, __put_user_handle_exception)

150
	_ASM_EXTABLE_UA(6b, __put_user_handle_exception)

151
	_ASM_EXTABLE_UA(7b, __put_user_handle_exception)

152
	_ASM_EXTABLE_UA(9b, __put_user_handle_exception)

153
#ifdef CONFIG_X86_32

154
	_ASM_EXTABLE_UA(8b, __put_user_handle_exception)

155
	_ASM_EXTABLE_UA(10b, __put_user_handle_exception)

156
#endif

157


158