]>
Commit | Line | Data |
---|---|---|
f5e706ad SR |
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> | |
f5e706ad SR |
15 | #endif |
16 | ||
17 | #ifndef __ASSEMBLY__ | |
18 | ||
2c66f623 DM |
19 | #include <asm/processor.h> |
20 | ||
ad6561df RR |
21 | #define ARCH_HAS_SORT_EXTABLE |
22 | #define ARCH_HAS_SEARCH_EXTABLE | |
23 | ||
f5e706ad SR |
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 | ||
8ccf7b25 | 40 | #define segment_eq(a, b) ((a).seg == (b).seg) |
f5e706ad SR |
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)) | |
8ccf7b25 MT |
49 | #define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size))) |
50 | #define access_ok(type, addr, size) \ | |
f5e706ad SR |
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 | ||
75 | struct exception_table_entry | |
76 | { | |
77 | unsigned long insn, fixup; | |
78 | }; | |
79 | ||
80 | /* Returns 0 if exception not found and fixup otherwise. */ | |
f05a6865 | 81 | unsigned long search_extables_range(unsigned long addr, unsigned long *g2); |
f5e706ad | 82 | |
f05a6865 | 83 | void __ret_efault(void); |
f5e706ad SR |
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 | */ | |
8ccf7b25 MT |
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 | }) | |
f5e706ad SR |
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 | */ | |
8ccf7b25 MT |
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))) | |
f5e706ad SR |
115 | |
116 | struct __large_struct { unsigned long buf[100]; }; | |
117 | #define __m(x) ((struct __large_struct __user *)(x)) | |
118 | ||
8ccf7b25 MT |
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 | ||
0795cb1b MT |
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; \ | |
8ccf7b25 MT |
153 | } \ |
154 | __pu_ret; \ | |
155 | }) | |
156 | ||
157 | #define __put_user_asm(x, size, addr, ret) \ | |
f5e706ad | 158 | __asm__ __volatile__( \ |
8ccf7b25 MT |
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)) | |
f5e706ad | 175 | |
f05a6865 | 176 | int __put_user_bad(void); |
f5e706ad | 177 | |
8ccf7b25 MT |
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 | ||
0795cb1b MT |
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; \ | |
8ccf7b25 MT |
223 | }) |
224 | ||
8ccf7b25 | 225 | #define __get_user_asm(x, size, addr, ret) \ |
f5e706ad | 226 | __asm__ __volatile__( \ |
8ccf7b25 MT |
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 | ||
f05a6865 | 245 | int __get_user_bad(void); |
f5e706ad | 246 | |
f05a6865 | 247 | unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size); |
f5e706ad SR |
248 | |
249 | static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n) | |
250 | { | |
9d9208a1 KC |
251 | if (n && __access_ok((unsigned long) to, n)) { |
252 | if (!__builtin_constant_p(n)) | |
253 | check_object_size(from, n, true); | |
f5e706ad | 254 | return __copy_user(to, (__force void __user *) from, n); |
9d9208a1 | 255 | } else |
f5e706ad SR |
256 | return n; |
257 | } | |
258 | ||
259 | static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n) | |
260 | { | |
9d9208a1 KC |
261 | if (!__builtin_constant_p(n)) |
262 | check_object_size(from, n, true); | |
f5e706ad SR |
263 | return __copy_user(to, (__force void __user *) from, n); |
264 | } | |
265 | ||
266 | static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n) | |
267 | { | |
9d9208a1 KC |
268 | if (n && __access_ok((unsigned long) from, n)) { |
269 | if (!__builtin_constant_p(n)) | |
270 | check_object_size(to, n, false); | |
f5e706ad | 271 | return __copy_user((__force void __user *) to, from, n); |
917400ce AV |
272 | } else { |
273 | memset(to, 0, n); | |
f5e706ad | 274 | return n; |
917400ce | 275 | } |
f5e706ad SR |
276 | } |
277 | ||
278 | static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) | |
279 | { | |
280 | return __copy_user((__force void __user *) to, from, n); | |
281 | } | |
282 | ||
283 | #define __copy_to_user_inatomic __copy_to_user | |
284 | #define __copy_from_user_inatomic __copy_from_user | |
285 | ||
286 | static inline unsigned long __clear_user(void __user *addr, unsigned long size) | |
287 | { | |
288 | unsigned long ret; | |
289 | ||
290 | __asm__ __volatile__ ( | |
291 | ".section __ex_table,#alloc\n\t" | |
292 | ".align 4\n\t" | |
293 | ".word 1f,3\n\t" | |
294 | ".previous\n\t" | |
295 | "mov %2, %%o1\n" | |
296 | "1:\n\t" | |
297 | "call __bzero\n\t" | |
298 | " mov %1, %%o0\n\t" | |
299 | "mov %%o0, %0\n" | |
300 | : "=r" (ret) : "r" (addr), "r" (size) : | |
301 | "o0", "o1", "o2", "o3", "o4", "o5", "o7", | |
302 | "g1", "g2", "g3", "g4", "g5", "g7", "cc"); | |
303 | ||
304 | return ret; | |
305 | } | |
306 | ||
307 | static inline unsigned long clear_user(void __user *addr, unsigned long n) | |
308 | { | |
309 | if (n && __access_ok((unsigned long) addr, n)) | |
310 | return __clear_user(addr, n); | |
311 | else | |
312 | return n; | |
313 | } | |
314 | ||
f05a6865 SR |
315 | __must_check long strlen_user(const char __user *str); |
316 | __must_check long strnlen_user(const char __user *str, long n); | |
f5e706ad SR |
317 | |
318 | #endif /* __ASSEMBLY__ */ | |
319 | ||
320 | #endif /* _ASM_UACCESS_H */ |