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 <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 -EFAULT)
28 *
29 * Clobbers:	%ebx needed for task pointer
30 *
31 * These functions should not modify any other registers,
32 * as they get called from within inline assembly.
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
47SYM_FUNC_START(__put_user_1)
48	check_range size=1
49	ASM_STAC
501:	movb %al,(%_ASM_CX)
51	xor %ecx,%ecx
52	ASM_CLAC
53	RET
54SYM_FUNC_END(__put_user_1)
55EXPORT_SYMBOL(__put_user_1)
56
57SYM_FUNC_START(__put_user_nocheck_1)
58	ASM_STAC
592:	movb %al,(%_ASM_CX)
60	xor %ecx,%ecx
61	ASM_CLAC
62	RET
63SYM_FUNC_END(__put_user_nocheck_1)
64EXPORT_SYMBOL(__put_user_nocheck_1)
65
66SYM_FUNC_START(__put_user_2)
67	check_range size=2
68	ASM_STAC
693:	movw %ax,(%_ASM_CX)
70	xor %ecx,%ecx
71	ASM_CLAC
72	RET
73SYM_FUNC_END(__put_user_2)
74EXPORT_SYMBOL(__put_user_2)
75
76SYM_FUNC_START(__put_user_nocheck_2)
77	ASM_STAC
784:	movw %ax,(%_ASM_CX)
79	xor %ecx,%ecx
80	ASM_CLAC
81	RET
82SYM_FUNC_END(__put_user_nocheck_2)
83EXPORT_SYMBOL(__put_user_nocheck_2)
84
85SYM_FUNC_START(__put_user_4)
86	check_range size=4
87	ASM_STAC
885:	movl %eax,(%_ASM_CX)
89	xor %ecx,%ecx
90	ASM_CLAC
91	RET
92SYM_FUNC_END(__put_user_4)
93EXPORT_SYMBOL(__put_user_4)
94
95SYM_FUNC_START(__put_user_nocheck_4)
96	ASM_STAC
976:	movl %eax,(%_ASM_CX)
98	xor %ecx,%ecx
99	ASM_CLAC
100	RET
101SYM_FUNC_END(__put_user_nocheck_4)
102EXPORT_SYMBOL(__put_user_nocheck_4)
103
104SYM_FUNC_START(__put_user_8)
105	check_range size=8
106	ASM_STAC
1077:	mov %_ASM_AX,(%_ASM_CX)
108#ifdef CONFIG_X86_32
1098:	movl %edx,4(%_ASM_CX)
110#endif
111	xor %ecx,%ecx
112	ASM_CLAC
113	RET
114SYM_FUNC_END(__put_user_8)
115EXPORT_SYMBOL(__put_user_8)
116
117SYM_FUNC_START(__put_user_nocheck_8)
118	ASM_STAC
1199:	mov %_ASM_AX,(%_ASM_CX)
120#ifdef CONFIG_X86_32
12110:	movl %edx,4(%_ASM_CX)
122#endif
123	xor %ecx,%ecx
124	ASM_CLAC
125	RET
126SYM_FUNC_END(__put_user_nocheck_8)
127EXPORT_SYMBOL(__put_user_nocheck_8)
128
129SYM_CODE_START_LOCAL(__put_user_handle_exception)
130	ASM_CLAC
131.Lbad_put_user:
132	movl $-EFAULT,%ecx
133	RET
134SYM_CODE_END(__put_user_handle_exception)
135
136	_ASM_EXTABLE_UA(1b, __put_user_handle_exception)
137	_ASM_EXTABLE_UA(2b, __put_user_handle_exception)
138	_ASM_EXTABLE_UA(3b, __put_user_handle_exception)
139	_ASM_EXTABLE_UA(4b, __put_user_handle_exception)
140	_ASM_EXTABLE_UA(5b, __put_user_handle_exception)
141	_ASM_EXTABLE_UA(6b, __put_user_handle_exception)
142	_ASM_EXTABLE_UA(7b, __put_user_handle_exception)
143	_ASM_EXTABLE_UA(9b, __put_user_handle_exception)
144#ifdef CONFIG_X86_32
145	_ASM_EXTABLE_UA(8b, __put_user_handle_exception)
146	_ASM_EXTABLE_UA(10b, __put_user_handle_exception)
147#endif
148