Loading...
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * uaccess.h: User space memore access functions.
4 *
5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7 */
8#ifndef _ASM_UACCESS_H
9#define _ASM_UACCESS_H
10
11#include <linux/compiler.h>
12#include <linux/string.h>
13
14#include <asm/processor.h>
15
16#define ARCH_HAS_SORT_EXTABLE
17#define ARCH_HAS_SEARCH_EXTABLE
18
19/* Sparc is not segmented, however we need to be able to fool access_ok()
20 * when doing system calls from kernel mode legitimately.
21 *
22 * "For historical reasons, these macros are grossly misnamed." -Linus
23 */
24
25#define KERNEL_DS ((mm_segment_t) { 0 })
26#define USER_DS ((mm_segment_t) { -1 })
27
28#define get_fs() (current->thread.current_ds)
29#define set_fs(val) ((current->thread.current_ds) = (val))
30
31#define segment_eq(a, b) ((a).seg == (b).seg)
32
33/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
34 * can be fairly lightweight.
35 * No one can read/write anything from userland in the kernel space by setting
36 * large size and address near to PAGE_OFFSET - a fault will break his intentions.
37 */
38#define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; })
39#define __kernel_ok (uaccess_kernel())
40#define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size)))
41#define access_ok(addr, size) __access_ok((unsigned long)(addr), size)
42
43/*
44 * The exception table consists of pairs of addresses: the first is the
45 * address of an instruction that is allowed to fault, and the second is
46 * the address at which the program should continue. No registers are
47 * modified, so it is entirely up to the continuation code to figure out
48 * what to do.
49 *
50 * All the routines below use bits of fixup code that are out of line
51 * with the main instruction path. This means when everything is well,
52 * we don't even have to jump over them. Further, they do not intrude
53 * on our cache or tlb entries.
54 *
55 * There is a special way how to put a range of potentially faulting
56 * insns (like twenty ldd/std's with now intervening other instructions)
57 * You specify address of first in insn and 0 in fixup and in the next
58 * exception_table_entry you specify last potentially faulting insn + 1
59 * and in fixup the routine which should handle the fault.
60 * That fixup code will get
61 * (faulting_insn_address - first_insn_in_the_range_address)/4
62 * in %g2 (ie. index of the faulting instruction in the range).
63 */
64
65struct exception_table_entry
66{
67 unsigned long insn, fixup;
68};
69
70/* Returns 0 if exception not found and fixup otherwise. */
71unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
72
73/* Uh, these should become the main single-value transfer routines..
74 * They automatically use the right size if we just have the right
75 * pointer type..
76 *
77 * This gets kind of ugly. We want to return _two_ values in "get_user()"
78 * and yet we don't want to do any pointers, because that is too much
79 * of a performance impact. Thus we have a few rather ugly macros here,
80 * and hide all the ugliness from the user.
81 */
82#define put_user(x, ptr) ({ \
83 unsigned long __pu_addr = (unsigned long)(ptr); \
84 __chk_user_ptr(ptr); \
85 __put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \
86})
87
88#define get_user(x, ptr) ({ \
89 unsigned long __gu_addr = (unsigned long)(ptr); \
90 __chk_user_ptr(ptr); \
91 __get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \
92})
93
94/*
95 * The "__xxx" versions do not do address space checking, useful when
96 * doing multiple accesses to the same area (the user has to do the
97 * checks by hand with "access_ok()")
98 */
99#define __put_user(x, ptr) \
100 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
101#define __get_user(x, ptr) \
102 __get_user_nocheck((x), (ptr), sizeof(*(ptr)), __typeof__(*(ptr)))
103
104struct __large_struct { unsigned long buf[100]; };
105#define __m(x) ((struct __large_struct __user *)(x))
106
107#define __put_user_check(x, addr, size) ({ \
108 register int __pu_ret; \
109 if (__access_ok(addr, size)) { \
110 switch (size) { \
111 case 1: \
112 __put_user_asm(x, b, addr, __pu_ret); \
113 break; \
114 case 2: \
115 __put_user_asm(x, h, addr, __pu_ret); \
116 break; \
117 case 4: \
118 __put_user_asm(x, , addr, __pu_ret); \
119 break; \
120 case 8: \
121 __put_user_asm(x, d, addr, __pu_ret); \
122 break; \
123 default: \
124 __pu_ret = __put_user_bad(); \
125 break; \
126 } \
127 } else { \
128 __pu_ret = -EFAULT; \
129 } \
130 __pu_ret; \
131})
132
133#define __put_user_nocheck(x, addr, size) ({ \
134 register int __pu_ret; \
135 switch (size) { \
136 case 1: __put_user_asm(x, b, addr, __pu_ret); break; \
137 case 2: __put_user_asm(x, h, addr, __pu_ret); break; \
138 case 4: __put_user_asm(x, , addr, __pu_ret); break; \
139 case 8: __put_user_asm(x, d, addr, __pu_ret); break; \
140 default: __pu_ret = __put_user_bad(); break; \
141 } \
142 __pu_ret; \
143})
144
145#define __put_user_asm(x, size, addr, ret) \
146__asm__ __volatile__( \
147 "/* Put user asm, inline. */\n" \
148 "1:\t" "st"#size " %1, %2\n\t" \
149 "clr %0\n" \
150 "2:\n\n\t" \
151 ".section .fixup,#alloc,#execinstr\n\t" \
152 ".align 4\n" \
153 "3:\n\t" \
154 "b 2b\n\t" \
155 " mov %3, %0\n\t" \
156 ".previous\n\n\t" \
157 ".section __ex_table,#alloc\n\t" \
158 ".align 4\n\t" \
159 ".word 1b, 3b\n\t" \
160 ".previous\n\n\t" \
161 : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \
162 "i" (-EFAULT))
163
164int __put_user_bad(void);
165
166#define __get_user_check(x, addr, size, type) ({ \
167 register int __gu_ret; \
168 register unsigned long __gu_val; \
169 if (__access_ok(addr, size)) { \
170 switch (size) { \
171 case 1: \
172 __get_user_asm(__gu_val, ub, addr, __gu_ret); \
173 break; \
174 case 2: \
175 __get_user_asm(__gu_val, uh, addr, __gu_ret); \
176 break; \
177 case 4: \
178 __get_user_asm(__gu_val, , addr, __gu_ret); \
179 break; \
180 case 8: \
181 __get_user_asm(__gu_val, d, addr, __gu_ret); \
182 break; \
183 default: \
184 __gu_val = 0; \
185 __gu_ret = __get_user_bad(); \
186 break; \
187 } \
188 } else { \
189 __gu_val = 0; \
190 __gu_ret = -EFAULT; \
191 } \
192 x = (__force type) __gu_val; \
193 __gu_ret; \
194})
195
196#define __get_user_nocheck(x, addr, size, type) ({ \
197 register int __gu_ret; \
198 register unsigned long __gu_val; \
199 switch (size) { \
200 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
201 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
202 case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \
203 case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \
204 default: \
205 __gu_val = 0; \
206 __gu_ret = __get_user_bad(); \
207 break; \
208 } \
209 x = (__force type) __gu_val; \
210 __gu_ret; \
211})
212
213#define __get_user_asm(x, size, addr, ret) \
214__asm__ __volatile__( \
215 "/* Get user asm, inline. */\n" \
216 "1:\t" "ld"#size " %2, %1\n\t" \
217 "clr %0\n" \
218 "2:\n\n\t" \
219 ".section .fixup,#alloc,#execinstr\n\t" \
220 ".align 4\n" \
221 "3:\n\t" \
222 "clr %1\n\t" \
223 "b 2b\n\t" \
224 " mov %3, %0\n\n\t" \
225 ".previous\n\t" \
226 ".section __ex_table,#alloc\n\t" \
227 ".align 4\n\t" \
228 ".word 1b, 3b\n\n\t" \
229 ".previous\n\t" \
230 : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \
231 "i" (-EFAULT))
232
233int __get_user_bad(void);
234
235unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
236
237static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
238{
239 return __copy_user(to, (__force void __user *) from, n);
240}
241
242static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
243{
244 return __copy_user((__force void __user *) to, from, n);
245}
246
247#define INLINE_COPY_FROM_USER
248#define INLINE_COPY_TO_USER
249
250static inline unsigned long __clear_user(void __user *addr, unsigned long size)
251{
252 unsigned long ret;
253
254 __asm__ __volatile__ (
255 ".section __ex_table,#alloc\n\t"
256 ".align 4\n\t"
257 ".word 1f,3\n\t"
258 ".previous\n\t"
259 "mov %2, %%o1\n"
260 "1:\n\t"
261 "call __bzero\n\t"
262 " mov %1, %%o0\n\t"
263 "mov %%o0, %0\n"
264 : "=r" (ret) : "r" (addr), "r" (size) :
265 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
266 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
267
268 return ret;
269}
270
271static inline unsigned long clear_user(void __user *addr, unsigned long n)
272{
273 if (n && __access_ok((unsigned long) addr, n))
274 return __clear_user(addr, n);
275 else
276 return n;
277}
278
279__must_check long strnlen_user(const char __user *str, long n);
280
281#endif /* _ASM_UACCESS_H */
1/*
2 * uaccess.h: User space memore access functions.
3 *
4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6 */
7#ifndef _ASM_UACCESS_H
8#define _ASM_UACCESS_H
9
10#ifdef __KERNEL__
11#include <linux/compiler.h>
12#include <linux/sched.h>
13#include <linux/string.h>
14#include <linux/errno.h>
15#endif
16
17#ifndef __ASSEMBLY__
18
19#include <asm/processor.h>
20
21#define ARCH_HAS_SORT_EXTABLE
22#define ARCH_HAS_SEARCH_EXTABLE
23
24/* Sparc is not segmented, however we need to be able to fool access_ok()
25 * when doing system calls from kernel mode legitimately.
26 *
27 * "For historical reasons, these macros are grossly misnamed." -Linus
28 */
29
30#define KERNEL_DS ((mm_segment_t) { 0 })
31#define USER_DS ((mm_segment_t) { -1 })
32
33#define VERIFY_READ 0
34#define VERIFY_WRITE 1
35
36#define get_ds() (KERNEL_DS)
37#define get_fs() (current->thread.current_ds)
38#define set_fs(val) ((current->thread.current_ds) = (val))
39
40#define segment_eq(a, b) ((a).seg == (b).seg)
41
42/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
43 * can be fairly lightweight.
44 * No one can read/write anything from userland in the kernel space by setting
45 * large size and address near to PAGE_OFFSET - a fault will break his intentions.
46 */
47#define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; })
48#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
49#define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size)))
50#define access_ok(type, addr, size) \
51 ({ (void)(type); __access_ok((unsigned long)(addr), size); })
52
53/*
54 * The exception table consists of pairs of addresses: the first is the
55 * address of an instruction that is allowed to fault, and the second is
56 * the address at which the program should continue. No registers are
57 * modified, so it is entirely up to the continuation code to figure out
58 * what to do.
59 *
60 * All the routines below use bits of fixup code that are out of line
61 * with the main instruction path. This means when everything is well,
62 * we don't even have to jump over them. Further, they do not intrude
63 * on our cache or tlb entries.
64 *
65 * There is a special way how to put a range of potentially faulting
66 * insns (like twenty ldd/std's with now intervening other instructions)
67 * You specify address of first in insn and 0 in fixup and in the next
68 * exception_table_entry you specify last potentially faulting insn + 1
69 * and in fixup the routine which should handle the fault.
70 * That fixup code will get
71 * (faulting_insn_address - first_insn_in_the_range_address)/4
72 * in %g2 (ie. index of the faulting instruction in the range).
73 */
74
75struct exception_table_entry
76{
77 unsigned long insn, fixup;
78};
79
80/* Returns 0 if exception not found and fixup otherwise. */
81unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
82
83void __ret_efault(void);
84
85/* Uh, these should become the main single-value transfer routines..
86 * They automatically use the right size if we just have the right
87 * pointer type..
88 *
89 * This gets kind of ugly. We want to return _two_ values in "get_user()"
90 * and yet we don't want to do any pointers, because that is too much
91 * of a performance impact. Thus we have a few rather ugly macros here,
92 * and hide all the ugliness from the user.
93 */
94#define put_user(x, ptr) ({ \
95 unsigned long __pu_addr = (unsigned long)(ptr); \
96 __chk_user_ptr(ptr); \
97 __put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \
98})
99
100#define get_user(x, ptr) ({ \
101 unsigned long __gu_addr = (unsigned long)(ptr); \
102 __chk_user_ptr(ptr); \
103 __get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \
104})
105
106/*
107 * The "__xxx" versions do not do address space checking, useful when
108 * doing multiple accesses to the same area (the user has to do the
109 * checks by hand with "access_ok()")
110 */
111#define __put_user(x, ptr) \
112 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
113#define __get_user(x, ptr) \
114 __get_user_nocheck((x), (ptr), sizeof(*(ptr)), __typeof__(*(ptr)))
115
116struct __large_struct { unsigned long buf[100]; };
117#define __m(x) ((struct __large_struct __user *)(x))
118
119#define __put_user_check(x, addr, size) ({ \
120 register int __pu_ret; \
121 if (__access_ok(addr, size)) { \
122 switch (size) { \
123 case 1: \
124 __put_user_asm(x, b, addr, __pu_ret); \
125 break; \
126 case 2: \
127 __put_user_asm(x, h, addr, __pu_ret); \
128 break; \
129 case 4: \
130 __put_user_asm(x, , addr, __pu_ret); \
131 break; \
132 case 8: \
133 __put_user_asm(x, d, addr, __pu_ret); \
134 break; \
135 default: \
136 __pu_ret = __put_user_bad(); \
137 break; \
138 } \
139 } else { \
140 __pu_ret = -EFAULT; \
141 } \
142 __pu_ret; \
143})
144
145#define __put_user_nocheck(x, addr, size) ({ \
146 register int __pu_ret; \
147 switch (size) { \
148 case 1: __put_user_asm(x, b, addr, __pu_ret); break; \
149 case 2: __put_user_asm(x, h, addr, __pu_ret); break; \
150 case 4: __put_user_asm(x, , addr, __pu_ret); break; \
151 case 8: __put_user_asm(x, d, addr, __pu_ret); break; \
152 default: __pu_ret = __put_user_bad(); break; \
153 } \
154 __pu_ret; \
155})
156
157#define __put_user_asm(x, size, addr, ret) \
158__asm__ __volatile__( \
159 "/* Put user asm, inline. */\n" \
160 "1:\t" "st"#size " %1, %2\n\t" \
161 "clr %0\n" \
162 "2:\n\n\t" \
163 ".section .fixup,#alloc,#execinstr\n\t" \
164 ".align 4\n" \
165 "3:\n\t" \
166 "b 2b\n\t" \
167 " mov %3, %0\n\t" \
168 ".previous\n\n\t" \
169 ".section __ex_table,#alloc\n\t" \
170 ".align 4\n\t" \
171 ".word 1b, 3b\n\t" \
172 ".previous\n\n\t" \
173 : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \
174 "i" (-EFAULT))
175
176int __put_user_bad(void);
177
178#define __get_user_check(x, addr, size, type) ({ \
179 register int __gu_ret; \
180 register unsigned long __gu_val; \
181 if (__access_ok(addr, size)) { \
182 switch (size) { \
183 case 1: \
184 __get_user_asm(__gu_val, ub, addr, __gu_ret); \
185 break; \
186 case 2: \
187 __get_user_asm(__gu_val, uh, addr, __gu_ret); \
188 break; \
189 case 4: \
190 __get_user_asm(__gu_val, , addr, __gu_ret); \
191 break; \
192 case 8: \
193 __get_user_asm(__gu_val, d, addr, __gu_ret); \
194 break; \
195 default: \
196 __gu_val = 0; \
197 __gu_ret = __get_user_bad(); \
198 break; \
199 } \
200 } else { \
201 __gu_val = 0; \
202 __gu_ret = -EFAULT; \
203 } \
204 x = (__force type) __gu_val; \
205 __gu_ret; \
206})
207
208#define __get_user_nocheck(x, addr, size, type) ({ \
209 register int __gu_ret; \
210 register unsigned long __gu_val; \
211 switch (size) { \
212 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
213 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
214 case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \
215 case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \
216 default: \
217 __gu_val = 0; \
218 __gu_ret = __get_user_bad(); \
219 break; \
220 } \
221 x = (__force type) __gu_val; \
222 __gu_ret; \
223})
224
225#define __get_user_asm(x, size, addr, ret) \
226__asm__ __volatile__( \
227 "/* Get user asm, inline. */\n" \
228 "1:\t" "ld"#size " %2, %1\n\t" \
229 "clr %0\n" \
230 "2:\n\n\t" \
231 ".section .fixup,#alloc,#execinstr\n\t" \
232 ".align 4\n" \
233 "3:\n\t" \
234 "clr %1\n\t" \
235 "b 2b\n\t" \
236 " mov %3, %0\n\n\t" \
237 ".previous\n\t" \
238 ".section __ex_table,#alloc\n\t" \
239 ".align 4\n\t" \
240 ".word 1b, 3b\n\n\t" \
241 ".previous\n\t" \
242 : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \
243 "i" (-EFAULT))
244
245int __get_user_bad(void);
246
247unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
248
249static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
250{
251 if (n && __access_ok((unsigned long) to, n))
252 return __copy_user(to, (__force void __user *) from, n);
253 else
254 return n;
255}
256
257static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
258{
259 return __copy_user(to, (__force void __user *) from, n);
260}
261
262static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
263{
264 if (n && __access_ok((unsigned long) from, n))
265 return __copy_user((__force void __user *) to, from, n);
266 else
267 return n;
268}
269
270static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
271{
272 return __copy_user((__force void __user *) to, from, n);
273}
274
275#define __copy_to_user_inatomic __copy_to_user
276#define __copy_from_user_inatomic __copy_from_user
277
278static inline unsigned long __clear_user(void __user *addr, unsigned long size)
279{
280 unsigned long ret;
281
282 __asm__ __volatile__ (
283 ".section __ex_table,#alloc\n\t"
284 ".align 4\n\t"
285 ".word 1f,3\n\t"
286 ".previous\n\t"
287 "mov %2, %%o1\n"
288 "1:\n\t"
289 "call __bzero\n\t"
290 " mov %1, %%o0\n\t"
291 "mov %%o0, %0\n"
292 : "=r" (ret) : "r" (addr), "r" (size) :
293 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
294 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
295
296 return ret;
297}
298
299static inline unsigned long clear_user(void __user *addr, unsigned long n)
300{
301 if (n && __access_ok((unsigned long) addr, n))
302 return __clear_user(addr, n);
303 else
304 return n;
305}
306
307__must_check long strlen_user(const char __user *str);
308__must_check long strnlen_user(const char __user *str, long n);
309
310#endif /* __ASSEMBLY__ */
311
312#endif /* _ASM_UACCESS_H */