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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 | */ | |
44 | #define __user_ok(addr,size) ((addr) < STACK_TOP) | |
45 | #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS)) | |
46 | #define __access_ok(addr,size) (__user_ok((addr) & get_fs().seg,(size))) | |
47 | #define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size)) | |
48 | ||
49 | /* this function will go away soon - use access_ok() instead */ | |
50 | static inline int __deprecated verify_area(int type, const void __user * addr, unsigned long size) | |
51 | { | |
52 | return access_ok(type,addr,size) ? 0 : -EFAULT; | |
53 | } | |
54 | ||
55 | /* | |
56 | * The exception table consists of pairs of addresses: the first is the | |
57 | * address of an instruction that is allowed to fault, and the second is | |
58 | * the address at which the program should continue. No registers are | |
59 | * modified, so it is entirely up to the continuation code to figure out | |
60 | * what to do. | |
61 | * | |
62 | * All the routines below use bits of fixup code that are out of line | |
63 | * with the main instruction path. This means when everything is well, | |
64 | * we don't even have to jump over them. Further, they do not intrude | |
65 | * on our cache or tlb entries. | |
66 | * | |
67 | * There is a special way how to put a range of potentially faulting | |
68 | * insns (like twenty ldd/std's with now intervening other instructions) | |
69 | * You specify address of first in insn and 0 in fixup and in the next | |
70 | * exception_table_entry you specify last potentially faulting insn + 1 | |
71 | * and in fixup the routine which should handle the fault. | |
72 | * That fixup code will get | |
73 | * (faulting_insn_address - first_insn_in_the_range_address)/4 | |
74 | * in %g2 (ie. index of the faulting instruction in the range). | |
75 | */ | |
76 | ||
77 | struct exception_table_entry | |
78 | { | |
79 | unsigned long insn, fixup; | |
80 | }; | |
81 | ||
82 | /* Returns 0 if exception not found and fixup otherwise. */ | |
83 | extern unsigned long search_extables_range(unsigned long addr, unsigned long *g2); | |
84 | ||
85 | extern void __ret_efault(void); | |
86 | ||
87 | /* Uh, these should become the main single-value transfer routines.. | |
88 | * They automatically use the right size if we just have the right | |
89 | * pointer type.. | |
90 | * | |
91 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
92 | * and yet we don't want to do any pointers, because that is too much | |
93 | * of a performance impact. Thus we have a few rather ugly macros here, | |
94 | * and hide all the ugliness from the user. | |
95 | */ | |
96 | #define put_user(x,ptr) ({ \ | |
97 | unsigned long __pu_addr = (unsigned long)(ptr); \ | |
98 | __chk_user_ptr(ptr); \ | |
99 | __put_user_check((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); }) | |
100 | ||
101 | #define get_user(x,ptr) ({ \ | |
102 | unsigned long __gu_addr = (unsigned long)(ptr); \ | |
103 | __chk_user_ptr(ptr); \ | |
104 | __get_user_check((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); }) | |
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) __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) | |
112 | #define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)),__typeof__(*(ptr))) | |
113 | ||
114 | struct __large_struct { unsigned long buf[100]; }; | |
115 | #define __m(x) ((struct __large_struct __user *)(x)) | |
116 | ||
117 | #define __put_user_check(x,addr,size) ({ \ | |
118 | register int __pu_ret; \ | |
119 | if (__access_ok(addr,size)) { \ | |
120 | switch (size) { \ | |
121 | case 1: __put_user_asm(x,b,addr,__pu_ret); break; \ | |
122 | case 2: __put_user_asm(x,h,addr,__pu_ret); break; \ | |
123 | case 4: __put_user_asm(x,,addr,__pu_ret); break; \ | |
124 | case 8: __put_user_asm(x,d,addr,__pu_ret); break; \ | |
125 | default: __pu_ret = __put_user_bad(); break; \ | |
126 | } } else { __pu_ret = -EFAULT; } __pu_ret; }) | |
127 | ||
128 | #define __put_user_check_ret(x,addr,size,retval) ({ \ | |
129 | register int __foo __asm__ ("l1"); \ | |
130 | if (__access_ok(addr,size)) { \ | |
131 | switch (size) { \ | |
132 | case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \ | |
133 | case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \ | |
134 | case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \ | |
135 | case 8: __put_user_asm_ret(x,d,addr,retval,__foo); break; \ | |
136 | default: if (__put_user_bad()) return retval; break; \ | |
137 | } } else return retval; }) | |
138 | ||
139 | #define __put_user_nocheck(x,addr,size) ({ \ | |
140 | register int __pu_ret; \ | |
141 | switch (size) { \ | |
142 | case 1: __put_user_asm(x,b,addr,__pu_ret); break; \ | |
143 | case 2: __put_user_asm(x,h,addr,__pu_ret); break; \ | |
144 | case 4: __put_user_asm(x,,addr,__pu_ret); break; \ | |
145 | case 8: __put_user_asm(x,d,addr,__pu_ret); break; \ | |
146 | default: __pu_ret = __put_user_bad(); break; \ | |
147 | } __pu_ret; }) | |
148 | ||
149 | #define __put_user_nocheck_ret(x,addr,size,retval) ({ \ | |
150 | register int __foo __asm__ ("l1"); \ | |
151 | switch (size) { \ | |
152 | case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \ | |
153 | case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \ | |
154 | case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \ | |
155 | case 8: __put_user_asm_ret(x,d,addr,retval,__foo); break; \ | |
156 | default: if (__put_user_bad()) return retval; break; \ | |
157 | } }) | |
158 | ||
159 | #define __put_user_asm(x,size,addr,ret) \ | |
160 | __asm__ __volatile__( \ | |
161 | "/* Put user asm, inline. */\n" \ | |
162 | "1:\t" "st"#size " %1, %2\n\t" \ | |
163 | "clr %0\n" \ | |
164 | "2:\n\n\t" \ | |
165 | ".section .fixup,#alloc,#execinstr\n\t" \ | |
166 | ".align 4\n" \ | |
167 | "3:\n\t" \ | |
168 | "b 2b\n\t" \ | |
169 | " mov %3, %0\n\t" \ | |
170 | ".previous\n\n\t" \ | |
171 | ".section __ex_table,#alloc\n\t" \ | |
172 | ".align 4\n\t" \ | |
173 | ".word 1b, 3b\n\t" \ | |
174 | ".previous\n\n\t" \ | |
175 | : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \ | |
176 | "i" (-EFAULT)) | |
177 | ||
178 | #define __put_user_asm_ret(x,size,addr,ret,foo) \ | |
179 | if (__builtin_constant_p(ret) && ret == -EFAULT) \ | |
180 | __asm__ __volatile__( \ | |
181 | "/* Put user asm ret, inline. */\n" \ | |
182 | "1:\t" "st"#size " %1, %2\n\n\t" \ | |
183 | ".section __ex_table,#alloc\n\t" \ | |
184 | ".align 4\n\t" \ | |
185 | ".word 1b, __ret_efault\n\n\t" \ | |
186 | ".previous\n\n\t" \ | |
187 | : "=r" (foo) : "r" (x), "m" (*__m(addr))); \ | |
188 | else \ | |
189 | __asm__ __volatile( \ | |
190 | "/* Put user asm ret, inline. */\n" \ | |
191 | "1:\t" "st"#size " %1, %2\n\n\t" \ | |
192 | ".section .fixup,#alloc,#execinstr\n\t" \ | |
193 | ".align 4\n" \ | |
194 | "3:\n\t" \ | |
195 | "ret\n\t" \ | |
196 | " restore %%g0, %3, %%o0\n\t" \ | |
197 | ".previous\n\n\t" \ | |
198 | ".section __ex_table,#alloc\n\t" \ | |
199 | ".align 4\n\t" \ | |
200 | ".word 1b, 3b\n\n\t" \ | |
201 | ".previous\n\n\t" \ | |
202 | : "=r" (foo) : "r" (x), "m" (*__m(addr)), "i" (ret)) | |
203 | ||
204 | extern int __put_user_bad(void); | |
205 | ||
206 | #define __get_user_check(x,addr,size,type) ({ \ | |
207 | register int __gu_ret; \ | |
208 | register unsigned long __gu_val; \ | |
209 | if (__access_ok(addr,size)) { \ | |
210 | switch (size) { \ | |
211 | case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \ | |
212 | case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \ | |
213 | case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \ | |
214 | case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \ | |
215 | default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \ | |
216 | } } else { __gu_val = 0; __gu_ret = -EFAULT; } x = (type) __gu_val; __gu_ret; }) | |
217 | ||
218 | #define __get_user_check_ret(x,addr,size,type,retval) ({ \ | |
219 | register unsigned long __gu_val __asm__ ("l1"); \ | |
220 | if (__access_ok(addr,size)) { \ | |
221 | switch (size) { \ | |
222 | case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \ | |
223 | case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \ | |
224 | case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \ | |
225 | case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \ | |
226 | default: if (__get_user_bad()) return retval; \ | |
227 | } x = (type) __gu_val; } else return retval; }) | |
228 | ||
229 | #define __get_user_nocheck(x,addr,size,type) ({ \ | |
230 | register int __gu_ret; \ | |
231 | register unsigned long __gu_val; \ | |
232 | switch (size) { \ | |
233 | case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \ | |
234 | case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \ | |
235 | case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \ | |
236 | case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \ | |
237 | default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \ | |
238 | } x = (type) __gu_val; __gu_ret; }) | |
239 | ||
240 | #define __get_user_nocheck_ret(x,addr,size,type,retval) ({ \ | |
241 | register unsigned long __gu_val __asm__ ("l1"); \ | |
242 | switch (size) { \ | |
243 | case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \ | |
244 | case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \ | |
245 | case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \ | |
246 | case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \ | |
247 | default: if (__get_user_bad()) return retval; \ | |
248 | } x = (type) __gu_val; }) | |
249 | ||
250 | #define __get_user_asm(x,size,addr,ret) \ | |
251 | __asm__ __volatile__( \ | |
252 | "/* Get user asm, inline. */\n" \ | |
253 | "1:\t" "ld"#size " %2, %1\n\t" \ | |
254 | "clr %0\n" \ | |
255 | "2:\n\n\t" \ | |
256 | ".section .fixup,#alloc,#execinstr\n\t" \ | |
257 | ".align 4\n" \ | |
258 | "3:\n\t" \ | |
259 | "clr %1\n\t" \ | |
260 | "b 2b\n\t" \ | |
261 | " mov %3, %0\n\n\t" \ | |
262 | ".previous\n\t" \ | |
263 | ".section __ex_table,#alloc\n\t" \ | |
264 | ".align 4\n\t" \ | |
265 | ".word 1b, 3b\n\n\t" \ | |
266 | ".previous\n\t" \ | |
267 | : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \ | |
268 | "i" (-EFAULT)) | |
269 | ||
270 | #define __get_user_asm_ret(x,size,addr,retval) \ | |
271 | if (__builtin_constant_p(retval) && retval == -EFAULT) \ | |
272 | __asm__ __volatile__( \ | |
273 | "/* Get user asm ret, inline. */\n" \ | |
274 | "1:\t" "ld"#size " %1, %0\n\n\t" \ | |
275 | ".section __ex_table,#alloc\n\t" \ | |
276 | ".align 4\n\t" \ | |
277 | ".word 1b,__ret_efault\n\n\t" \ | |
278 | ".previous\n\t" \ | |
279 | : "=&r" (x) : "m" (*__m(addr))); \ | |
280 | else \ | |
281 | __asm__ __volatile__( \ | |
282 | "/* Get user asm ret, inline. */\n" \ | |
283 | "1:\t" "ld"#size " %1, %0\n\n\t" \ | |
284 | ".section .fixup,#alloc,#execinstr\n\t" \ | |
285 | ".align 4\n" \ | |
286 | "3:\n\t" \ | |
287 | "ret\n\t" \ | |
288 | " restore %%g0, %2, %%o0\n\n\t" \ | |
289 | ".previous\n\t" \ | |
290 | ".section __ex_table,#alloc\n\t" \ | |
291 | ".align 4\n\t" \ | |
292 | ".word 1b, 3b\n\n\t" \ | |
293 | ".previous\n\t" \ | |
294 | : "=&r" (x) : "m" (*__m(addr)), "i" (retval)) | |
295 | ||
296 | extern int __get_user_bad(void); | |
297 | ||
298 | extern unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size); | |
299 | ||
300 | static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n) | |
301 | { | |
302 | if (n && __access_ok((unsigned long) to, n)) | |
303 | return __copy_user(to, (__force void __user *) from, n); | |
304 | else | |
305 | return n; | |
306 | } | |
307 | ||
308 | static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n) | |
309 | { | |
310 | return __copy_user(to, (__force void __user *) from, n); | |
311 | } | |
312 | ||
313 | static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n) | |
314 | { | |
315 | if (n && __access_ok((unsigned long) from, n)) | |
316 | return __copy_user((__force void __user *) to, from, n); | |
317 | else | |
318 | return n; | |
319 | } | |
320 | ||
321 | static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) | |
322 | { | |
323 | return __copy_user((__force void __user *) to, from, n); | |
324 | } | |
325 | ||
326 | #define __copy_to_user_inatomic __copy_to_user | |
327 | #define __copy_from_user_inatomic __copy_from_user | |
328 | ||
329 | static inline unsigned long __clear_user(void __user *addr, unsigned long size) | |
330 | { | |
331 | unsigned long ret; | |
332 | ||
333 | __asm__ __volatile__ ( | |
334 | ".section __ex_table,#alloc\n\t" | |
335 | ".align 4\n\t" | |
336 | ".word 1f,3\n\t" | |
337 | ".previous\n\t" | |
338 | "mov %2, %%o1\n" | |
339 | "1:\n\t" | |
340 | "call __bzero\n\t" | |
341 | " mov %1, %%o0\n\t" | |
342 | "mov %%o0, %0\n" | |
343 | : "=r" (ret) : "r" (addr), "r" (size) : | |
344 | "o0", "o1", "o2", "o3", "o4", "o5", "o7", | |
345 | "g1", "g2", "g3", "g4", "g5", "g7", "cc"); | |
346 | ||
347 | return ret; | |
348 | } | |
349 | ||
350 | static inline unsigned long clear_user(void __user *addr, unsigned long n) | |
351 | { | |
352 | if (n && __access_ok((unsigned long) addr, n)) | |
353 | return __clear_user(addr, n); | |
354 | else | |
355 | return n; | |
356 | } | |
357 | ||
358 | extern long __strncpy_from_user(char *dest, const char __user *src, long count); | |
359 | ||
360 | static inline long strncpy_from_user(char *dest, const char __user *src, long count) | |
361 | { | |
362 | if (__access_ok((unsigned long) src, count)) | |
363 | return __strncpy_from_user(dest, src, count); | |
364 | else | |
365 | return -EFAULT; | |
366 | } | |
367 | ||
368 | extern long __strlen_user(const char __user *); | |
369 | extern long __strnlen_user(const char __user *, long len); | |
370 | ||
371 | static inline long strlen_user(const char __user *str) | |
372 | { | |
373 | if (!access_ok(VERIFY_READ, str, 0)) | |
374 | return 0; | |
375 | else | |
376 | return __strlen_user(str); | |
377 | } | |
378 | ||
379 | static inline long strnlen_user(const char __user *str, long len) | |
380 | { | |
381 | if (!access_ok(VERIFY_READ, str, 0)) | |
382 | return 0; | |
383 | else | |
384 | return __strnlen_user(str, len); | |
385 | } | |
386 | ||
387 | #endif /* __ASSEMBLY__ */ | |
388 | ||
389 | #endif /* _ASM_UACCESS_H */ |