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1da177e4 LT |
1 | /* $Id: uaccess.h,v 1.24 2001/10/30 04:32:24 davem Exp $ |
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 | #include <asm/vac-ops.h> | |
16 | #include <asm/a.out.h> | |
17 | #endif | |
18 | ||
19 | #ifndef __ASSEMBLY__ | |
20 | ||
e49332bd | 21 | /* Sparc is not segmented, however we need to be able to fool access_ok() |
1da177e4 LT |
22 | * when doing system calls from kernel mode legitimately. |
23 | * | |
24 | * "For historical reasons, these macros are grossly misnamed." -Linus | |
25 | */ | |
26 | ||
27 | #define KERNEL_DS ((mm_segment_t) { 0 }) | |
28 | #define USER_DS ((mm_segment_t) { -1 }) | |
29 | ||
30 | #define VERIFY_READ 0 | |
31 | #define VERIFY_WRITE 1 | |
32 | ||
33 | #define get_ds() (KERNEL_DS) | |
34 | #define get_fs() (current->thread.current_ds) | |
35 | #define set_fs(val) ((current->thread.current_ds) = (val)) | |
36 | ||
37 | #define segment_eq(a,b) ((a).seg == (b).seg) | |
38 | ||
39 | /* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test | |
40 | * can be fairly lightweight. | |
41 | * No one can read/write anything from userland in the kernel space by setting | |
42 | * large size and address near to PAGE_OFFSET - a fault will break his intentions. | |
43 | */ | |
f8acd944 | 44 | #define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; }) |
1da177e4 LT |
45 | #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS)) |
46 | #define __access_ok(addr,size) (__user_ok((addr) & get_fs().seg,(size))) | |
f8acd944 WLII |
47 | #define access_ok(type, addr, size) \ |
48 | ({ (void)(type); __access_ok((unsigned long)(addr), size); }) | |
1da177e4 | 49 | |
1da177e4 LT |
50 | /* |
51 | * The exception table consists of pairs of addresses: the first is the | |
52 | * address of an instruction that is allowed to fault, and the second is | |
53 | * the address at which the program should continue. No registers are | |
54 | * modified, so it is entirely up to the continuation code to figure out | |
55 | * what to do. | |
56 | * | |
57 | * All the routines below use bits of fixup code that are out of line | |
58 | * with the main instruction path. This means when everything is well, | |
59 | * we don't even have to jump over them. Further, they do not intrude | |
60 | * on our cache or tlb entries. | |
61 | * | |
62 | * There is a special way how to put a range of potentially faulting | |
63 | * insns (like twenty ldd/std's with now intervening other instructions) | |
64 | * You specify address of first in insn and 0 in fixup and in the next | |
65 | * exception_table_entry you specify last potentially faulting insn + 1 | |
66 | * and in fixup the routine which should handle the fault. | |
67 | * That fixup code will get | |
68 | * (faulting_insn_address - first_insn_in_the_range_address)/4 | |
69 | * in %g2 (ie. index of the faulting instruction in the range). | |
70 | */ | |
71 | ||
72 | struct exception_table_entry | |
73 | { | |
74 | unsigned long insn, fixup; | |
75 | }; | |
76 | ||
77 | /* Returns 0 if exception not found and fixup otherwise. */ | |
78 | extern unsigned long search_extables_range(unsigned long addr, unsigned long *g2); | |
79 | ||
80 | extern void __ret_efault(void); | |
81 | ||
82 | /* Uh, these should become the main single-value transfer routines.. | |
83 | * They automatically use the right size if we just have the right | |
84 | * pointer type.. | |
85 | * | |
86 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
87 | * and yet we don't want to do any pointers, because that is too much | |
88 | * of a performance impact. Thus we have a few rather ugly macros here, | |
89 | * and hide all the ugliness from the user. | |
90 | */ | |
91 | #define put_user(x,ptr) ({ \ | |
92 | unsigned long __pu_addr = (unsigned long)(ptr); \ | |
93 | __chk_user_ptr(ptr); \ | |
94 | __put_user_check((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); }) | |
95 | ||
96 | #define get_user(x,ptr) ({ \ | |
97 | unsigned long __gu_addr = (unsigned long)(ptr); \ | |
98 | __chk_user_ptr(ptr); \ | |
99 | __get_user_check((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); }) | |
100 | ||
101 | /* | |
102 | * The "__xxx" versions do not do address space checking, useful when | |
103 | * doing multiple accesses to the same area (the user has to do the | |
104 | * checks by hand with "access_ok()") | |
105 | */ | |
106 | #define __put_user(x,ptr) __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) | |
107 | #define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)),__typeof__(*(ptr))) | |
108 | ||
109 | struct __large_struct { unsigned long buf[100]; }; | |
110 | #define __m(x) ((struct __large_struct __user *)(x)) | |
111 | ||
112 | #define __put_user_check(x,addr,size) ({ \ | |
113 | register int __pu_ret; \ | |
114 | if (__access_ok(addr,size)) { \ | |
115 | switch (size) { \ | |
116 | case 1: __put_user_asm(x,b,addr,__pu_ret); break; \ | |
117 | case 2: __put_user_asm(x,h,addr,__pu_ret); break; \ | |
118 | case 4: __put_user_asm(x,,addr,__pu_ret); break; \ | |
119 | case 8: __put_user_asm(x,d,addr,__pu_ret); break; \ | |
120 | default: __pu_ret = __put_user_bad(); break; \ | |
121 | } } else { __pu_ret = -EFAULT; } __pu_ret; }) | |
122 | ||
1da177e4 LT |
123 | #define __put_user_nocheck(x,addr,size) ({ \ |
124 | register int __pu_ret; \ | |
125 | switch (size) { \ | |
126 | case 1: __put_user_asm(x,b,addr,__pu_ret); break; \ | |
127 | case 2: __put_user_asm(x,h,addr,__pu_ret); break; \ | |
128 | case 4: __put_user_asm(x,,addr,__pu_ret); break; \ | |
129 | case 8: __put_user_asm(x,d,addr,__pu_ret); break; \ | |
130 | default: __pu_ret = __put_user_bad(); break; \ | |
131 | } __pu_ret; }) | |
132 | ||
1da177e4 LT |
133 | #define __put_user_asm(x,size,addr,ret) \ |
134 | __asm__ __volatile__( \ | |
135 | "/* Put user asm, inline. */\n" \ | |
136 | "1:\t" "st"#size " %1, %2\n\t" \ | |
137 | "clr %0\n" \ | |
138 | "2:\n\n\t" \ | |
139 | ".section .fixup,#alloc,#execinstr\n\t" \ | |
140 | ".align 4\n" \ | |
141 | "3:\n\t" \ | |
142 | "b 2b\n\t" \ | |
143 | " mov %3, %0\n\t" \ | |
144 | ".previous\n\n\t" \ | |
145 | ".section __ex_table,#alloc\n\t" \ | |
146 | ".align 4\n\t" \ | |
147 | ".word 1b, 3b\n\t" \ | |
148 | ".previous\n\n\t" \ | |
149 | : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \ | |
150 | "i" (-EFAULT)) | |
151 | ||
1da177e4 LT |
152 | extern int __put_user_bad(void); |
153 | ||
154 | #define __get_user_check(x,addr,size,type) ({ \ | |
155 | register int __gu_ret; \ | |
156 | register unsigned long __gu_val; \ | |
157 | if (__access_ok(addr,size)) { \ | |
158 | switch (size) { \ | |
159 | case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \ | |
160 | case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \ | |
161 | case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \ | |
162 | case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \ | |
163 | default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \ | |
164 | } } else { __gu_val = 0; __gu_ret = -EFAULT; } x = (type) __gu_val; __gu_ret; }) | |
165 | ||
166 | #define __get_user_check_ret(x,addr,size,type,retval) ({ \ | |
167 | register unsigned long __gu_val __asm__ ("l1"); \ | |
168 | if (__access_ok(addr,size)) { \ | |
169 | switch (size) { \ | |
170 | case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \ | |
171 | case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \ | |
172 | case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \ | |
173 | case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \ | |
174 | default: if (__get_user_bad()) return retval; \ | |
175 | } x = (type) __gu_val; } else return retval; }) | |
176 | ||
177 | #define __get_user_nocheck(x,addr,size,type) ({ \ | |
178 | register int __gu_ret; \ | |
179 | register unsigned long __gu_val; \ | |
180 | switch (size) { \ | |
181 | case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \ | |
182 | case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \ | |
183 | case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \ | |
184 | case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \ | |
185 | default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \ | |
186 | } x = (type) __gu_val; __gu_ret; }) | |
187 | ||
188 | #define __get_user_nocheck_ret(x,addr,size,type,retval) ({ \ | |
189 | register unsigned long __gu_val __asm__ ("l1"); \ | |
190 | switch (size) { \ | |
191 | case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \ | |
192 | case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \ | |
193 | case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \ | |
194 | case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \ | |
195 | default: if (__get_user_bad()) return retval; \ | |
196 | } x = (type) __gu_val; }) | |
197 | ||
198 | #define __get_user_asm(x,size,addr,ret) \ | |
199 | __asm__ __volatile__( \ | |
200 | "/* Get user asm, inline. */\n" \ | |
201 | "1:\t" "ld"#size " %2, %1\n\t" \ | |
202 | "clr %0\n" \ | |
203 | "2:\n\n\t" \ | |
204 | ".section .fixup,#alloc,#execinstr\n\t" \ | |
205 | ".align 4\n" \ | |
206 | "3:\n\t" \ | |
207 | "clr %1\n\t" \ | |
208 | "b 2b\n\t" \ | |
209 | " mov %3, %0\n\n\t" \ | |
210 | ".previous\n\t" \ | |
211 | ".section __ex_table,#alloc\n\t" \ | |
212 | ".align 4\n\t" \ | |
213 | ".word 1b, 3b\n\n\t" \ | |
214 | ".previous\n\t" \ | |
215 | : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \ | |
216 | "i" (-EFAULT)) | |
217 | ||
218 | #define __get_user_asm_ret(x,size,addr,retval) \ | |
219 | if (__builtin_constant_p(retval) && retval == -EFAULT) \ | |
220 | __asm__ __volatile__( \ | |
221 | "/* Get user asm ret, inline. */\n" \ | |
222 | "1:\t" "ld"#size " %1, %0\n\n\t" \ | |
223 | ".section __ex_table,#alloc\n\t" \ | |
224 | ".align 4\n\t" \ | |
225 | ".word 1b,__ret_efault\n\n\t" \ | |
226 | ".previous\n\t" \ | |
227 | : "=&r" (x) : "m" (*__m(addr))); \ | |
228 | else \ | |
229 | __asm__ __volatile__( \ | |
230 | "/* Get user asm ret, inline. */\n" \ | |
231 | "1:\t" "ld"#size " %1, %0\n\n\t" \ | |
232 | ".section .fixup,#alloc,#execinstr\n\t" \ | |
233 | ".align 4\n" \ | |
234 | "3:\n\t" \ | |
235 | "ret\n\t" \ | |
236 | " restore %%g0, %2, %%o0\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" (x) : "m" (*__m(addr)), "i" (retval)) | |
243 | ||
244 | extern int __get_user_bad(void); | |
245 | ||
246 | extern unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size); | |
247 | ||
248 | static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n) | |
249 | { | |
250 | if (n && __access_ok((unsigned long) to, n)) | |
251 | return __copy_user(to, (__force void __user *) from, n); | |
252 | else | |
253 | return n; | |
254 | } | |
255 | ||
256 | static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n) | |
257 | { | |
258 | return __copy_user(to, (__force void __user *) from, n); | |
259 | } | |
260 | ||
261 | static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n) | |
262 | { | |
263 | if (n && __access_ok((unsigned long) from, n)) | |
264 | return __copy_user((__force void __user *) to, from, n); | |
265 | else | |
266 | return n; | |
267 | } | |
268 | ||
269 | static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) | |
270 | { | |
271 | return __copy_user((__force void __user *) to, from, n); | |
272 | } | |
273 | ||
274 | #define __copy_to_user_inatomic __copy_to_user | |
275 | #define __copy_from_user_inatomic __copy_from_user | |
276 | ||
277 | static inline unsigned long __clear_user(void __user *addr, unsigned long size) | |
278 | { | |
279 | unsigned long ret; | |
280 | ||
281 | __asm__ __volatile__ ( | |
282 | ".section __ex_table,#alloc\n\t" | |
283 | ".align 4\n\t" | |
284 | ".word 1f,3\n\t" | |
285 | ".previous\n\t" | |
286 | "mov %2, %%o1\n" | |
287 | "1:\n\t" | |
288 | "call __bzero\n\t" | |
289 | " mov %1, %%o0\n\t" | |
290 | "mov %%o0, %0\n" | |
291 | : "=r" (ret) : "r" (addr), "r" (size) : | |
292 | "o0", "o1", "o2", "o3", "o4", "o5", "o7", | |
293 | "g1", "g2", "g3", "g4", "g5", "g7", "cc"); | |
294 | ||
295 | return ret; | |
296 | } | |
297 | ||
298 | static inline unsigned long clear_user(void __user *addr, unsigned long n) | |
299 | { | |
300 | if (n && __access_ok((unsigned long) addr, n)) | |
301 | return __clear_user(addr, n); | |
302 | else | |
303 | return n; | |
304 | } | |
305 | ||
306 | extern long __strncpy_from_user(char *dest, const char __user *src, long count); | |
307 | ||
308 | static inline long strncpy_from_user(char *dest, const char __user *src, long count) | |
309 | { | |
310 | if (__access_ok((unsigned long) src, count)) | |
311 | return __strncpy_from_user(dest, src, count); | |
312 | else | |
313 | return -EFAULT; | |
314 | } | |
315 | ||
316 | extern long __strlen_user(const char __user *); | |
317 | extern long __strnlen_user(const char __user *, long len); | |
318 | ||
319 | static inline long strlen_user(const char __user *str) | |
320 | { | |
321 | if (!access_ok(VERIFY_READ, str, 0)) | |
322 | return 0; | |
323 | else | |
324 | return __strlen_user(str); | |
325 | } | |
326 | ||
327 | static inline long strnlen_user(const char __user *str, long len) | |
328 | { | |
329 | if (!access_ok(VERIFY_READ, str, 0)) | |
330 | return 0; | |
331 | else | |
332 | return __strnlen_user(str, len); | |
333 | } | |
334 | ||
335 | #endif /* __ASSEMBLY__ */ | |
336 | ||
337 | #endif /* _ASM_UACCESS_H */ |