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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#include <asm-generic/access_ok.h>
16
17/* Uh, these should become the main single-value transfer routines..
18 * They automatically use the right size if we just have the right
19 * pointer type..
20 *
21 * This gets kind of ugly. We want to return _two_ values in "get_user()"
22 * and yet we don't want to do any pointers, because that is too much
23 * of a performance impact. Thus we have a few rather ugly macros here,
24 * and hide all the ugliness from the user.
25 */
26#define put_user(x, ptr) ({ \
27 void __user *__pu_addr = (ptr); \
28 __chk_user_ptr(ptr); \
29 __put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \
30})
31
32#define get_user(x, ptr) ({ \
33 const void __user *__gu_addr = (ptr); \
34 __chk_user_ptr(ptr); \
35 __get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \
36})
37
38/*
39 * The "__xxx" versions do not do address space checking, useful when
40 * doing multiple accesses to the same area (the user has to do the
41 * checks by hand with "access_ok()")
42 */
43#define __put_user(x, ptr) \
44 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
45#define __get_user(x, ptr) \
46 __get_user_nocheck((x), (ptr), sizeof(*(ptr)), __typeof__(*(ptr)))
47
48struct __large_struct { unsigned long buf[100]; };
49#define __m(x) ((struct __large_struct __user *)(x))
50
51#define __put_user_check(x, addr, size) ({ \
52 register int __pu_ret; \
53 if (__access_ok(addr, size)) { \
54 switch (size) { \
55 case 1: \
56 __put_user_asm(x, b, addr, __pu_ret); \
57 break; \
58 case 2: \
59 __put_user_asm(x, h, addr, __pu_ret); \
60 break; \
61 case 4: \
62 __put_user_asm(x, , addr, __pu_ret); \
63 break; \
64 case 8: \
65 __put_user_asm(x, d, addr, __pu_ret); \
66 break; \
67 default: \
68 __pu_ret = __put_user_bad(); \
69 break; \
70 } \
71 } else { \
72 __pu_ret = -EFAULT; \
73 } \
74 __pu_ret; \
75})
76
77#define __put_user_nocheck(x, addr, size) ({ \
78 register int __pu_ret; \
79 switch (size) { \
80 case 1: __put_user_asm(x, b, addr, __pu_ret); break; \
81 case 2: __put_user_asm(x, h, addr, __pu_ret); break; \
82 case 4: __put_user_asm(x, , addr, __pu_ret); break; \
83 case 8: __put_user_asm(x, d, addr, __pu_ret); break; \
84 default: __pu_ret = __put_user_bad(); break; \
85 } \
86 __pu_ret; \
87})
88
89#define __put_user_asm(x, size, addr, ret) \
90__asm__ __volatile__( \
91 "/* Put user asm, inline. */\n" \
92 "1:\t" "st"#size " %1, %2\n\t" \
93 "clr %0\n" \
94 "2:\n\n\t" \
95 ".section .fixup,#alloc,#execinstr\n\t" \
96 ".align 4\n" \
97 "3:\n\t" \
98 "b 2b\n\t" \
99 " mov %3, %0\n\t" \
100 ".previous\n\n\t" \
101 ".section __ex_table,#alloc\n\t" \
102 ".align 4\n\t" \
103 ".word 1b, 3b\n\t" \
104 ".previous\n\n\t" \
105 : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \
106 "i" (-EFAULT))
107
108int __put_user_bad(void);
109
110#define __get_user_check(x, addr, size, type) ({ \
111 register int __gu_ret; \
112 register unsigned long __gu_val; \
113 if (__access_ok(addr, size)) { \
114 switch (size) { \
115 case 1: \
116 __get_user_asm(__gu_val, ub, addr, __gu_ret); \
117 break; \
118 case 2: \
119 __get_user_asm(__gu_val, uh, addr, __gu_ret); \
120 break; \
121 case 4: \
122 __get_user_asm(__gu_val, , addr, __gu_ret); \
123 break; \
124 case 8: \
125 __get_user_asm(__gu_val, d, addr, __gu_ret); \
126 break; \
127 default: \
128 __gu_val = 0; \
129 __gu_ret = __get_user_bad(); \
130 break; \
131 } \
132 } else { \
133 __gu_val = 0; \
134 __gu_ret = -EFAULT; \
135 } \
136 x = (__force type) __gu_val; \
137 __gu_ret; \
138})
139
140#define __get_user_nocheck(x, addr, size, type) ({ \
141 register int __gu_ret; \
142 register unsigned long __gu_val; \
143 switch (size) { \
144 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
145 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
146 case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \
147 case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \
148 default: \
149 __gu_val = 0; \
150 __gu_ret = __get_user_bad(); \
151 break; \
152 } \
153 x = (__force type) __gu_val; \
154 __gu_ret; \
155})
156
157#define __get_user_asm(x, size, addr, ret) \
158__asm__ __volatile__( \
159 "/* Get user asm, inline. */\n" \
160 "1:\t" "ld"#size " %2, %1\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 "clr %1\n\t" \
167 "b 2b\n\t" \
168 " mov %3, %0\n\n\t" \
169 ".previous\n\t" \
170 ".section __ex_table,#alloc\n\t" \
171 ".align 4\n\t" \
172 ".word 1b, 3b\n\n\t" \
173 ".previous\n\t" \
174 : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \
175 "i" (-EFAULT))
176
177int __get_user_bad(void);
178
179unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
180
181static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
182{
183 return __copy_user(to, (__force void __user *) from, n);
184}
185
186static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
187{
188 return __copy_user((__force void __user *) to, from, n);
189}
190
191#define INLINE_COPY_FROM_USER
192#define INLINE_COPY_TO_USER
193
194static inline unsigned long __clear_user(void __user *addr, unsigned long size)
195{
196 unsigned long ret;
197
198 __asm__ __volatile__ (
199 "mov %2, %%o1\n"
200 "call __bzero\n\t"
201 " mov %1, %%o0\n\t"
202 "mov %%o0, %0\n"
203 : "=r" (ret) : "r" (addr), "r" (size) :
204 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
205 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
206
207 return ret;
208}
209
210static inline unsigned long clear_user(void __user *addr, unsigned long n)
211{
212 if (n && __access_ok(addr, n))
213 return __clear_user(addr, n);
214 else
215 return n;
216}
217
218__must_check long strnlen_user(const char __user *str, long n);
219
220#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 check_object_size(from, n, true);
253 return __copy_user(to, (__force void __user *) from, n);
254 } else
255 return n;
256}
257
258static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
259{
260 check_object_size(from, n, true);
261 return __copy_user(to, (__force void __user *) from, n);
262}
263
264static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
265{
266 if (n && __access_ok((unsigned long) from, n)) {
267 check_object_size(to, n, false);
268 return __copy_user((__force void __user *) to, from, n);
269 } else {
270 memset(to, 0, n);
271 return n;
272 }
273}
274
275static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
276{
277 return __copy_user((__force void __user *) to, from, n);
278}
279
280#define __copy_to_user_inatomic __copy_to_user
281#define __copy_from_user_inatomic __copy_from_user
282
283static inline unsigned long __clear_user(void __user *addr, unsigned long size)
284{
285 unsigned long ret;
286
287 __asm__ __volatile__ (
288 ".section __ex_table,#alloc\n\t"
289 ".align 4\n\t"
290 ".word 1f,3\n\t"
291 ".previous\n\t"
292 "mov %2, %%o1\n"
293 "1:\n\t"
294 "call __bzero\n\t"
295 " mov %1, %%o0\n\t"
296 "mov %%o0, %0\n"
297 : "=r" (ret) : "r" (addr), "r" (size) :
298 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
299 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
300
301 return ret;
302}
303
304static inline unsigned long clear_user(void __user *addr, unsigned long n)
305{
306 if (n && __access_ok((unsigned long) addr, n))
307 return __clear_user(addr, n);
308 else
309 return n;
310}
311
312__must_check long strlen_user(const char __user *str);
313__must_check long strnlen_user(const char __user *str, long n);
314
315#endif /* __ASSEMBLY__ */
316
317#endif /* _ASM_UACCESS_H */