Loading...
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_GENERIC_UACCESS_H
3#define __ASM_GENERIC_UACCESS_H
4
5/*
6 * User space memory access functions, these should work
7 * on any machine that has kernel and user data in the same
8 * address space, e.g. all NOMMU machines.
9 */
10#include <linux/string.h>
11
12#ifdef CONFIG_UACCESS_MEMCPY
13static inline __must_check unsigned long
14raw_copy_from_user(void *to, const void __user * from, unsigned long n)
15{
16 if (__builtin_constant_p(n)) {
17 switch(n) {
18 case 1:
19 *(u8 *)to = *(u8 __force *)from;
20 return 0;
21 case 2:
22 *(u16 *)to = *(u16 __force *)from;
23 return 0;
24 case 4:
25 *(u32 *)to = *(u32 __force *)from;
26 return 0;
27#ifdef CONFIG_64BIT
28 case 8:
29 *(u64 *)to = *(u64 __force *)from;
30 return 0;
31#endif
32 }
33 }
34
35 memcpy(to, (const void __force *)from, n);
36 return 0;
37}
38
39static inline __must_check unsigned long
40raw_copy_to_user(void __user *to, const void *from, unsigned long n)
41{
42 if (__builtin_constant_p(n)) {
43 switch(n) {
44 case 1:
45 *(u8 __force *)to = *(u8 *)from;
46 return 0;
47 case 2:
48 *(u16 __force *)to = *(u16 *)from;
49 return 0;
50 case 4:
51 *(u32 __force *)to = *(u32 *)from;
52 return 0;
53#ifdef CONFIG_64BIT
54 case 8:
55 *(u64 __force *)to = *(u64 *)from;
56 return 0;
57#endif
58 default:
59 break;
60 }
61 }
62
63 memcpy((void __force *)to, from, n);
64 return 0;
65}
66#define INLINE_COPY_FROM_USER
67#define INLINE_COPY_TO_USER
68#endif /* CONFIG_UACCESS_MEMCPY */
69
70#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
71
72#ifndef KERNEL_DS
73#define KERNEL_DS MAKE_MM_SEG(~0UL)
74#endif
75
76#ifndef USER_DS
77#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
78#endif
79
80#ifndef get_fs
81#define get_fs() (current_thread_info()->addr_limit)
82
83static inline void set_fs(mm_segment_t fs)
84{
85 current_thread_info()->addr_limit = fs;
86}
87#endif
88
89#ifndef segment_eq
90#define segment_eq(a, b) ((a).seg == (b).seg)
91#endif
92
93#define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))
94
95/*
96 * The architecture should really override this if possible, at least
97 * doing a check on the get_fs()
98 */
99#ifndef __access_ok
100static inline int __access_ok(unsigned long addr, unsigned long size)
101{
102 return 1;
103}
104#endif
105
106/*
107 * These are the main single-value transfer routines. They automatically
108 * use the right size if we just have the right pointer type.
109 * This version just falls back to copy_{from,to}_user, which should
110 * provide a fast-path for small values.
111 */
112#define __put_user(x, ptr) \
113({ \
114 __typeof__(*(ptr)) __x = (x); \
115 int __pu_err = -EFAULT; \
116 __chk_user_ptr(ptr); \
117 switch (sizeof (*(ptr))) { \
118 case 1: \
119 case 2: \
120 case 4: \
121 case 8: \
122 __pu_err = __put_user_fn(sizeof (*(ptr)), \
123 ptr, &__x); \
124 break; \
125 default: \
126 __put_user_bad(); \
127 break; \
128 } \
129 __pu_err; \
130})
131
132#define put_user(x, ptr) \
133({ \
134 void __user *__p = (ptr); \
135 might_fault(); \
136 access_ok(__p, sizeof(*ptr)) ? \
137 __put_user((x), ((__typeof__(*(ptr)) __user *)__p)) : \
138 -EFAULT; \
139})
140
141#ifndef __put_user_fn
142
143static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
144{
145 return unlikely(raw_copy_to_user(ptr, x, size)) ? -EFAULT : 0;
146}
147
148#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
149
150#endif
151
152extern int __put_user_bad(void) __attribute__((noreturn));
153
154#define __get_user(x, ptr) \
155({ \
156 int __gu_err = -EFAULT; \
157 __chk_user_ptr(ptr); \
158 switch (sizeof(*(ptr))) { \
159 case 1: { \
160 unsigned char __x = 0; \
161 __gu_err = __get_user_fn(sizeof (*(ptr)), \
162 ptr, &__x); \
163 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
164 break; \
165 }; \
166 case 2: { \
167 unsigned short __x = 0; \
168 __gu_err = __get_user_fn(sizeof (*(ptr)), \
169 ptr, &__x); \
170 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
171 break; \
172 }; \
173 case 4: { \
174 unsigned int __x = 0; \
175 __gu_err = __get_user_fn(sizeof (*(ptr)), \
176 ptr, &__x); \
177 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
178 break; \
179 }; \
180 case 8: { \
181 unsigned long long __x = 0; \
182 __gu_err = __get_user_fn(sizeof (*(ptr)), \
183 ptr, &__x); \
184 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
185 break; \
186 }; \
187 default: \
188 __get_user_bad(); \
189 break; \
190 } \
191 __gu_err; \
192})
193
194#define get_user(x, ptr) \
195({ \
196 const void __user *__p = (ptr); \
197 might_fault(); \
198 access_ok(__p, sizeof(*ptr)) ? \
199 __get_user((x), (__typeof__(*(ptr)) __user *)__p) :\
200 ((x) = (__typeof__(*(ptr)))0,-EFAULT); \
201})
202
203#ifndef __get_user_fn
204static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
205{
206 return unlikely(raw_copy_from_user(x, ptr, size)) ? -EFAULT : 0;
207}
208
209#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
210
211#endif
212
213extern int __get_user_bad(void) __attribute__((noreturn));
214
215/*
216 * Copy a null terminated string from userspace.
217 */
218#ifndef __strncpy_from_user
219static inline long
220__strncpy_from_user(char *dst, const char __user *src, long count)
221{
222 char *tmp;
223 strncpy(dst, (const char __force *)src, count);
224 for (tmp = dst; *tmp && count > 0; tmp++, count--)
225 ;
226 return (tmp - dst);
227}
228#endif
229
230static inline long
231strncpy_from_user(char *dst, const char __user *src, long count)
232{
233 if (!access_ok(src, 1))
234 return -EFAULT;
235 return __strncpy_from_user(dst, src, count);
236}
237
238/*
239 * Return the size of a string (including the ending 0)
240 *
241 * Return 0 on exception, a value greater than N if too long
242 */
243#ifndef __strnlen_user
244#define __strnlen_user(s, n) (strnlen((s), (n)) + 1)
245#endif
246
247/*
248 * Unlike strnlen, strnlen_user includes the nul terminator in
249 * its returned count. Callers should check for a returned value
250 * greater than N as an indication the string is too long.
251 */
252static inline long strnlen_user(const char __user *src, long n)
253{
254 if (!access_ok(src, 1))
255 return 0;
256 return __strnlen_user(src, n);
257}
258
259/*
260 * Zero Userspace
261 */
262#ifndef __clear_user
263static inline __must_check unsigned long
264__clear_user(void __user *to, unsigned long n)
265{
266 memset((void __force *)to, 0, n);
267 return 0;
268}
269#endif
270
271static inline __must_check unsigned long
272clear_user(void __user *to, unsigned long n)
273{
274 might_fault();
275 if (!access_ok(to, n))
276 return n;
277
278 return __clear_user(to, n);
279}
280
281#include <asm/extable.h>
282
283#endif /* __ASM_GENERIC_UACCESS_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_GENERIC_UACCESS_H
3#define __ASM_GENERIC_UACCESS_H
4
5/*
6 * User space memory access functions, these should work
7 * on any machine that has kernel and user data in the same
8 * address space, e.g. all NOMMU machines.
9 */
10#include <linux/string.h>
11
12#ifdef CONFIG_UACCESS_MEMCPY
13static inline __must_check unsigned long
14raw_copy_from_user(void *to, const void __user * from, unsigned long n)
15{
16 if (__builtin_constant_p(n)) {
17 switch(n) {
18 case 1:
19 *(u8 *)to = *(u8 __force *)from;
20 return 0;
21 case 2:
22 *(u16 *)to = *(u16 __force *)from;
23 return 0;
24 case 4:
25 *(u32 *)to = *(u32 __force *)from;
26 return 0;
27#ifdef CONFIG_64BIT
28 case 8:
29 *(u64 *)to = *(u64 __force *)from;
30 return 0;
31#endif
32 }
33 }
34
35 memcpy(to, (const void __force *)from, n);
36 return 0;
37}
38
39static inline __must_check unsigned long
40raw_copy_to_user(void __user *to, const void *from, unsigned long n)
41{
42 if (__builtin_constant_p(n)) {
43 switch(n) {
44 case 1:
45 *(u8 __force *)to = *(u8 *)from;
46 return 0;
47 case 2:
48 *(u16 __force *)to = *(u16 *)from;
49 return 0;
50 case 4:
51 *(u32 __force *)to = *(u32 *)from;
52 return 0;
53#ifdef CONFIG_64BIT
54 case 8:
55 *(u64 __force *)to = *(u64 *)from;
56 return 0;
57#endif
58 default:
59 break;
60 }
61 }
62
63 memcpy((void __force *)to, from, n);
64 return 0;
65}
66#define INLINE_COPY_FROM_USER
67#define INLINE_COPY_TO_USER
68#endif /* CONFIG_UACCESS_MEMCPY */
69
70#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
71
72#ifndef KERNEL_DS
73#define KERNEL_DS MAKE_MM_SEG(~0UL)
74#endif
75
76#ifndef USER_DS
77#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
78#endif
79
80#ifndef get_fs
81#define get_fs() (current_thread_info()->addr_limit)
82
83static inline void set_fs(mm_segment_t fs)
84{
85 current_thread_info()->addr_limit = fs;
86}
87#endif
88
89#ifndef uaccess_kernel
90#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
91#endif
92
93#define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))
94
95/*
96 * The architecture should really override this if possible, at least
97 * doing a check on the get_fs()
98 */
99#ifndef __access_ok
100static inline int __access_ok(unsigned long addr, unsigned long size)
101{
102 return 1;
103}
104#endif
105
106/*
107 * These are the main single-value transfer routines. They automatically
108 * use the right size if we just have the right pointer type.
109 * This version just falls back to copy_{from,to}_user, which should
110 * provide a fast-path for small values.
111 */
112#define __put_user(x, ptr) \
113({ \
114 __typeof__(*(ptr)) __x = (x); \
115 int __pu_err = -EFAULT; \
116 __chk_user_ptr(ptr); \
117 switch (sizeof (*(ptr))) { \
118 case 1: \
119 case 2: \
120 case 4: \
121 case 8: \
122 __pu_err = __put_user_fn(sizeof (*(ptr)), \
123 ptr, &__x); \
124 break; \
125 default: \
126 __put_user_bad(); \
127 break; \
128 } \
129 __pu_err; \
130})
131
132#define put_user(x, ptr) \
133({ \
134 void __user *__p = (ptr); \
135 might_fault(); \
136 access_ok(__p, sizeof(*ptr)) ? \
137 __put_user((x), ((__typeof__(*(ptr)) __user *)__p)) : \
138 -EFAULT; \
139})
140
141#ifndef __put_user_fn
142
143static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
144{
145 return unlikely(raw_copy_to_user(ptr, x, size)) ? -EFAULT : 0;
146}
147
148#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
149
150#endif
151
152extern int __put_user_bad(void) __attribute__((noreturn));
153
154#define __get_user(x, ptr) \
155({ \
156 int __gu_err = -EFAULT; \
157 __chk_user_ptr(ptr); \
158 switch (sizeof(*(ptr))) { \
159 case 1: { \
160 unsigned char __x = 0; \
161 __gu_err = __get_user_fn(sizeof (*(ptr)), \
162 ptr, &__x); \
163 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
164 break; \
165 }; \
166 case 2: { \
167 unsigned short __x = 0; \
168 __gu_err = __get_user_fn(sizeof (*(ptr)), \
169 ptr, &__x); \
170 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
171 break; \
172 }; \
173 case 4: { \
174 unsigned int __x = 0; \
175 __gu_err = __get_user_fn(sizeof (*(ptr)), \
176 ptr, &__x); \
177 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
178 break; \
179 }; \
180 case 8: { \
181 unsigned long long __x = 0; \
182 __gu_err = __get_user_fn(sizeof (*(ptr)), \
183 ptr, &__x); \
184 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
185 break; \
186 }; \
187 default: \
188 __get_user_bad(); \
189 break; \
190 } \
191 __gu_err; \
192})
193
194#define get_user(x, ptr) \
195({ \
196 const void __user *__p = (ptr); \
197 might_fault(); \
198 access_ok(__p, sizeof(*ptr)) ? \
199 __get_user((x), (__typeof__(*(ptr)) __user *)__p) :\
200 ((x) = (__typeof__(*(ptr)))0,-EFAULT); \
201})
202
203#ifndef __get_user_fn
204static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
205{
206 return unlikely(raw_copy_from_user(x, ptr, size)) ? -EFAULT : 0;
207}
208
209#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
210
211#endif
212
213extern int __get_user_bad(void) __attribute__((noreturn));
214
215/*
216 * Copy a null terminated string from userspace.
217 */
218#ifndef __strncpy_from_user
219static inline long
220__strncpy_from_user(char *dst, const char __user *src, long count)
221{
222 char *tmp;
223 strncpy(dst, (const char __force *)src, count);
224 for (tmp = dst; *tmp && count > 0; tmp++, count--)
225 ;
226 return (tmp - dst);
227}
228#endif
229
230static inline long
231strncpy_from_user(char *dst, const char __user *src, long count)
232{
233 if (!access_ok(src, 1))
234 return -EFAULT;
235 return __strncpy_from_user(dst, src, count);
236}
237
238/*
239 * Return the size of a string (including the ending 0)
240 *
241 * Return 0 on exception, a value greater than N if too long
242 */
243#ifndef __strnlen_user
244#define __strnlen_user(s, n) (strnlen((s), (n)) + 1)
245#endif
246
247/*
248 * Unlike strnlen, strnlen_user includes the nul terminator in
249 * its returned count. Callers should check for a returned value
250 * greater than N as an indication the string is too long.
251 */
252static inline long strnlen_user(const char __user *src, long n)
253{
254 if (!access_ok(src, 1))
255 return 0;
256 return __strnlen_user(src, n);
257}
258
259/*
260 * Zero Userspace
261 */
262#ifndef __clear_user
263static inline __must_check unsigned long
264__clear_user(void __user *to, unsigned long n)
265{
266 memset((void __force *)to, 0, n);
267 return 0;
268}
269#endif
270
271static inline __must_check unsigned long
272clear_user(void __user *to, unsigned long n)
273{
274 might_fault();
275 if (!access_ok(to, n))
276 return n;
277
278 return __clear_user(to, n);
279}
280
281#include <asm/extable.h>
282
283#endif /* __ASM_GENERIC_UACCESS_H */