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 in
10 * to make them more efficient, especially as
11 * return an error value in addition to the "r
12 * return value.
13 */
14 #include <linux/export.h>
15 #include <linux/linkage.h>
16 #include <asm/thread_info.h>
17 #include <asm/errno.h>
18 #include <asm/asm.h>
19 #include <asm/smap.h>
20
21 /*
22 * __put_user_X
23 *
24 * Inputs: %eax[:%edx] contains the data
25 * %ecx contains the address
26 *
27 * Outputs: %ecx is error code (0 or -EFAU
28 *
29 * Clobbers: %ebx needed for task pointer
30 *
31 * These functions should not modify any other
32 * as they get called from within inline assem
33 */
34
35 .macro check_range size:req
36 .if IS_ENABLED(CONFIG_X86_64)
37 mov %rcx, %rbx
38 sar $63, %rbx
39 or %rbx, %rcx
40 .else
41 cmp $TASK_SIZE_MAX-\size+1, %ecx
42 jae .Lbad_put_user
43 .endif
44 .endm
45
46 .text
47 SYM_FUNC_START(__put_user_1)
48 check_range size=1
49 ASM_STAC
50 1: movb %al,(%_ASM_CX)
51 xor %ecx,%ecx
52 ASM_CLAC
53 RET
54 SYM_FUNC_END(__put_user_1)
55 EXPORT_SYMBOL(__put_user_1)
56
57 SYM_FUNC_START(__put_user_nocheck_1)
58 ASM_STAC
59 2: movb %al,(%_ASM_CX)
60 xor %ecx,%ecx
61 ASM_CLAC
62 RET
63 SYM_FUNC_END(__put_user_nocheck_1)
64 EXPORT_SYMBOL(__put_user_nocheck_1)
65
66 SYM_FUNC_START(__put_user_2)
67 check_range size=2
68 ASM_STAC
69 3: movw %ax,(%_ASM_CX)
70 xor %ecx,%ecx
71 ASM_CLAC
72 RET
73 SYM_FUNC_END(__put_user_2)
74 EXPORT_SYMBOL(__put_user_2)
75
76 SYM_FUNC_START(__put_user_nocheck_2)
77 ASM_STAC
78 4: movw %ax,(%_ASM_CX)
79 xor %ecx,%ecx
80 ASM_CLAC
81 RET
82 SYM_FUNC_END(__put_user_nocheck_2)
83 EXPORT_SYMBOL(__put_user_nocheck_2)
84
85 SYM_FUNC_START(__put_user_4)
86 check_range size=4
87 ASM_STAC
88 5: movl %eax,(%_ASM_CX)
89 xor %ecx,%ecx
90 ASM_CLAC
91 RET
92 SYM_FUNC_END(__put_user_4)
93 EXPORT_SYMBOL(__put_user_4)
94
95 SYM_FUNC_START(__put_user_nocheck_4)
96 ASM_STAC
97 6: movl %eax,(%_ASM_CX)
98 xor %ecx,%ecx
99 ASM_CLAC
100 RET
101 SYM_FUNC_END(__put_user_nocheck_4)
102 EXPORT_SYMBOL(__put_user_nocheck_4)
103
104 SYM_FUNC_START(__put_user_8)
105 check_range size=8
106 ASM_STAC
107 7: mov %_ASM_AX,(%_ASM_CX)
108 #ifdef CONFIG_X86_32
109 8: movl %edx,4(%_ASM_CX)
110 #endif
111 xor %ecx,%ecx
112 ASM_CLAC
113 RET
114 SYM_FUNC_END(__put_user_8)
115 EXPORT_SYMBOL(__put_user_8)
116
117 SYM_FUNC_START(__put_user_nocheck_8)
118 ASM_STAC
119 9: mov %_ASM_AX,(%_ASM_CX)
120 #ifdef CONFIG_X86_32
121 10: movl %edx,4(%_ASM_CX)
122 #endif
123 xor %ecx,%ecx
124 ASM_CLAC
125 RET
126 SYM_FUNC_END(__put_user_nocheck_8)
127 EXPORT_SYMBOL(__put_user_nocheck_8)
128
129 SYM_CODE_START_LOCAL(__put_user_handle_excepti
130 ASM_CLAC
131 .Lbad_put_user:
132 movl $-EFAULT,%ecx
133 RET
134 SYM_CODE_END(__put_user_handle_exception)
135
136 _ASM_EXTABLE_UA(1b, __put_user_handle_
137 _ASM_EXTABLE_UA(2b, __put_user_handle_
138 _ASM_EXTABLE_UA(3b, __put_user_handle_
139 _ASM_EXTABLE_UA(4b, __put_user_handle_
140 _ASM_EXTABLE_UA(5b, __put_user_handle_
141 _ASM_EXTABLE_UA(6b, __put_user_handle_
142 _ASM_EXTABLE_UA(7b, __put_user_handle_
143 _ASM_EXTABLE_UA(9b, __put_user_handle_
144 #ifdef CONFIG_X86_32
145 _ASM_EXTABLE_UA(8b, __put_user_handle_
146 _ASM_EXTABLE_UA(10b, __put_user_handle
147 #endif
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