1 /* SPDX-License-Identifier: GPL-2.0 */
3 * __put_user functions.
5 * (C) Copyright 2005 Linus Torvalds
6 * (C) Copyright 2005 Andi Kleen
7 * (C) Copyright 2008 Glauber Costa
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"
14 #include <linux/linkage.h>
15 #include <asm/thread_info.h>
16 #include <asm/errno.h>
19 #include <asm/export.h>
25 * Inputs: %eax[:%edx] contains the data
26 * %ecx contains the address
28 * Outputs: %ecx is error code (0 or -EFAULT)
30 * Clobbers: %ebx needed for task pointer
32 * These functions should not modify any other registers,
33 * as they get called from within inline assembly.
36 #ifdef CONFIG_X86_5LEVEL
37 #define LOAD_TASK_SIZE_MINUS_N(n) \
38 ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rbx), \
39 __stringify(mov $((1 << 56) - 4096 - (n)),%rbx), X86_FEATURE_LA57
41 #define LOAD_TASK_SIZE_MINUS_N(n) \
42 mov $(TASK_SIZE_MAX - (n)),%_ASM_BX
46 SYM_FUNC_START(__put_user_1)
47 LOAD_TASK_SIZE_MINUS_N(0)
50 SYM_INNER_LABEL(__put_user_nocheck_1, SYM_L_GLOBAL)
53 1: movb %al,(%_ASM_CX)
57 SYM_FUNC_END(__put_user_1)
58 EXPORT_SYMBOL(__put_user_1)
59 EXPORT_SYMBOL(__put_user_nocheck_1)
61 SYM_FUNC_START(__put_user_2)
62 LOAD_TASK_SIZE_MINUS_N(1)
65 SYM_INNER_LABEL(__put_user_nocheck_2, SYM_L_GLOBAL)
68 2: movw %ax,(%_ASM_CX)
72 SYM_FUNC_END(__put_user_2)
73 EXPORT_SYMBOL(__put_user_2)
74 EXPORT_SYMBOL(__put_user_nocheck_2)
76 SYM_FUNC_START(__put_user_4)
77 LOAD_TASK_SIZE_MINUS_N(3)
80 SYM_INNER_LABEL(__put_user_nocheck_4, SYM_L_GLOBAL)
83 3: movl %eax,(%_ASM_CX)
87 SYM_FUNC_END(__put_user_4)
88 EXPORT_SYMBOL(__put_user_4)
89 EXPORT_SYMBOL(__put_user_nocheck_4)
91 SYM_FUNC_START(__put_user_8)
92 LOAD_TASK_SIZE_MINUS_N(7)
95 SYM_INNER_LABEL(__put_user_nocheck_8, SYM_L_GLOBAL)
98 4: mov %_ASM_AX,(%_ASM_CX)
100 5: movl %edx,4(%_ASM_CX)
105 SYM_FUNC_END(__put_user_8)
106 EXPORT_SYMBOL(__put_user_8)
107 EXPORT_SYMBOL(__put_user_nocheck_8)
109 SYM_CODE_START_LOCAL(.Lbad_put_user_clac)
114 SYM_CODE_END(.Lbad_put_user_clac)
116 _ASM_EXTABLE_UA(1b, .Lbad_put_user_clac)
117 _ASM_EXTABLE_UA(2b, .Lbad_put_user_clac)
118 _ASM_EXTABLE_UA(3b, .Lbad_put_user_clac)
119 _ASM_EXTABLE_UA(4b, .Lbad_put_user_clac)
121 _ASM_EXTABLE_UA(5b, .Lbad_put_user_clac)