1 /*
2 * Authors: Bjorn Wesen (bjornw@axis.com)
3 * Hans-Peter Nilsson (hp@axis.com)
4 */
5
6 /* Asm:s have been tweaked (within the domain of correctness) to give
7 satisfactory results for "gcc version 2.96 20000427 (experimental)".
8
9 Check regularly...
10
11 Register $r9 is chosen for temporaries, being a call-clobbered register
12 first in line to be used (notably for local blocks), not colliding with
13 parameter registers. */
14
15 #ifndef _CRIS_UACCESS_H
16 #define _CRIS_UACCESS_H
17
18 #ifndef __ASSEMBLY__
19 #include <linux/sched.h>
20 #include <linux/errno.h>
21 #include <asm/processor.h>
22 #include <asm/page.h>
23
24 #define VERIFY_READ 0
25 #define VERIFY_WRITE 1
26
27 /*
28 * The fs value determines whether argument validity checking should be
29 * performed or not. If get_fs() == USER_DS, checking is performed, with
30 * get_fs() == KERNEL_DS, checking is bypassed.
31 *
32 * For historical reasons, these macros are grossly misnamed.
33 */
34
35 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
36
37 /* addr_limit is the maximum accessible address for the task. we misuse
38 * the KERNEL_DS and USER_DS values to both assign and compare the
39 * addr_limit values through the equally misnamed get/set_fs macros.
40 * (see above)
41 */
42
43 #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
44 #define USER_DS MAKE_MM_SEG(TASK_SIZE)
45
46 #define get_ds() (KERNEL_DS)
47 #define get_fs() (current_thread_info()->addr_limit)
48 #define set_fs(x) (current_thread_info()->addr_limit = (x))
49
50 #define segment_eq(a,b) ((a).seg == (b).seg)
51
52 #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
53 #define __user_ok(addr,size) (((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size)))
54 #define __access_ok(addr,size) (__kernel_ok || __user_ok((addr),(size)))
55 #define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size))
56
57 #include <arch/uaccess.h>
58
59 /*
60 * The exception table consists of pairs of addresses: the first is the
61 * address of an instruction that is allowed to fault, and the second is
62 * the address at which the program should continue. No registers are
63 * modified, so it is entirely up to the continuation code to figure out
64 * what to do.
65 *
66 * All the routines below use bits of fixup code that are out of line
67 * with the main instruction path. This means when everything is well,
68 * we don't even have to jump over them. Further, they do not intrude
69 * on our cache or tlb entries.
70 */
71
72 struct exception_table_entry
73 {
74 unsigned long insn, fixup;
75 };
76
77 /*
78 * These are the main single-value transfer routines. They automatically
79 * use the right size if we just have the right pointer type.
80 *
81 * This gets kind of ugly. We want to return _two_ values in "get_user()"
82 * and yet we don't want to do any pointers, because that is too much
83 * of a performance impact. Thus we have a few rather ugly macros here,
84 * and hide all the ugliness from the user.
85 *
86 * The "__xxx" versions of the user access functions are versions that
87 * do not verify the address space, that must have been done previously
88 * with a separate "access_ok()" call (this is used when we do multiple
89 * accesses to the same area of user memory).
90 *
91 * As we use the same address space for kernel and user data on
92 * CRIS, we can just do these as direct assignments. (Of course, the
93 * exception handling means that it's no longer "just"...)
94 */
95 #define get_user(x,ptr) \
96 __get_user_check((x),(ptr),sizeof(*(ptr)))
97 #define put_user(x,ptr) \
98 __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
99
100 #define __get_user(x,ptr) \
101 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
102 #define __put_user(x,ptr) \
103 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
104
105 extern long __put_user_bad(void);
106
107 #define __put_user_size(x,ptr,size,retval) \
108 do { \
109 retval = 0; \
110 switch (size) { \
111 case 1: __put_user_asm(x,ptr,retval,"move.b"); break; \
112 case 2: __put_user_asm(x,ptr,retval,"move.w"); break; \
113 case 4: __put_user_asm(x,ptr,retval,"move.d"); break; \
114 case 8: __put_user_asm_64(x,ptr,retval); break; \
115 default: __put_user_bad(); \
116 } \
117 } while (0)
118
119 #define __get_user_size(x,ptr,size,retval) \
120 do { \
121 retval = 0; \
122 switch (size) { \
123 case 1: __get_user_asm(x,ptr,retval,"move.b"); break; \
124 case 2: __get_user_asm(x,ptr,retval,"move.w"); break; \
125 case 4: __get_user_asm(x,ptr,retval,"move.d"); break; \
126 case 8: __get_user_asm_64(x,ptr,retval); break; \
127 default: (x) = __get_user_bad(); \
128 } \
129 } while (0)
130
131 #define __put_user_nocheck(x,ptr,size) \
132 ({ \
133 long __pu_err; \
134 __put_user_size((x),(ptr),(size),__pu_err); \
135 __pu_err; \
136 })
137
138 #define __put_user_check(x,ptr,size) \
139 ({ \
140 long __pu_err = -EFAULT; \
141 __typeof__(*(ptr)) *__pu_addr = (ptr); \
142 if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
143 __put_user_size((x),__pu_addr,(size),__pu_err); \
144 __pu_err; \
145 })
146
147 struct __large_struct { unsigned long buf[100]; };
148 #define __m(x) (*(struct __large_struct *)(x))
149
150
151
152 #define __get_user_nocheck(x,ptr,size) \
153 ({ \
154 long __gu_err, __gu_val; \
155 __get_user_size(__gu_val,(ptr),(size),__gu_err); \
156 (x) = (__typeof__(*(ptr)))__gu_val; \
157 __gu_err; \
158 })
159
160 #define __get_user_check(x,ptr,size) \
161 ({ \
162 long __gu_err = -EFAULT, __gu_val = 0; \
163 const __typeof__(*(ptr)) *__gu_addr = (ptr); \
164 if (access_ok(VERIFY_READ,__gu_addr,size)) \
165 __get_user_size(__gu_val,__gu_addr,(size),__gu_err); \
166 (x) = (__typeof__(*(ptr)))__gu_val; \
167 __gu_err; \
168 })
169
170 extern long __get_user_bad(void);
171
172 /* More complex functions. Most are inline, but some call functions that
173 live in lib/usercopy.c */
174
175 extern unsigned long __copy_user(void __user *to, const void *from, unsigned long n);
176 extern unsigned long __copy_user_zeroing(void *to, const void __user *from, unsigned long n);
177 extern unsigned long __do_clear_user(void __user *to, unsigned long n);
178
179 static inline unsigned long
__generic_copy_to_user(void __user * to,const void * from,unsigned long n)180 __generic_copy_to_user(void __user *to, const void *from, unsigned long n)
181 {
182 if (access_ok(VERIFY_WRITE, to, n))
183 return __copy_user(to,from,n);
184 return n;
185 }
186
187 static inline unsigned long
__generic_copy_from_user(void * to,const void __user * from,unsigned long n)188 __generic_copy_from_user(void *to, const void __user *from, unsigned long n)
189 {
190 if (access_ok(VERIFY_READ, from, n))
191 return __copy_user_zeroing(to,from,n);
192 return n;
193 }
194
195 static inline unsigned long
__generic_clear_user(void __user * to,unsigned long n)196 __generic_clear_user(void __user *to, unsigned long n)
197 {
198 if (access_ok(VERIFY_WRITE, to, n))
199 return __do_clear_user(to,n);
200 return n;
201 }
202
203 static inline long
__strncpy_from_user(char * dst,const char __user * src,long count)204 __strncpy_from_user(char *dst, const char __user *src, long count)
205 {
206 return __do_strncpy_from_user(dst, src, count);
207 }
208
209 static inline long
strncpy_from_user(char * dst,const char __user * src,long count)210 strncpy_from_user(char *dst, const char __user *src, long count)
211 {
212 long res = -EFAULT;
213 if (access_ok(VERIFY_READ, src, 1))
214 res = __do_strncpy_from_user(dst, src, count);
215 return res;
216 }
217
218
219 /* Note that these expand awfully if made into switch constructs, so
220 don't do that. */
221
222 static inline unsigned long
__constant_copy_from_user(void * to,const void __user * from,unsigned long n)223 __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
224 {
225 unsigned long ret = 0;
226 if (n == 0)
227 ;
228 else if (n == 1)
229 __asm_copy_from_user_1(to, from, ret);
230 else if (n == 2)
231 __asm_copy_from_user_2(to, from, ret);
232 else if (n == 3)
233 __asm_copy_from_user_3(to, from, ret);
234 else if (n == 4)
235 __asm_copy_from_user_4(to, from, ret);
236 else if (n == 5)
237 __asm_copy_from_user_5(to, from, ret);
238 else if (n == 6)
239 __asm_copy_from_user_6(to, from, ret);
240 else if (n == 7)
241 __asm_copy_from_user_7(to, from, ret);
242 else if (n == 8)
243 __asm_copy_from_user_8(to, from, ret);
244 else if (n == 9)
245 __asm_copy_from_user_9(to, from, ret);
246 else if (n == 10)
247 __asm_copy_from_user_10(to, from, ret);
248 else if (n == 11)
249 __asm_copy_from_user_11(to, from, ret);
250 else if (n == 12)
251 __asm_copy_from_user_12(to, from, ret);
252 else if (n == 13)
253 __asm_copy_from_user_13(to, from, ret);
254 else if (n == 14)
255 __asm_copy_from_user_14(to, from, ret);
256 else if (n == 15)
257 __asm_copy_from_user_15(to, from, ret);
258 else if (n == 16)
259 __asm_copy_from_user_16(to, from, ret);
260 else if (n == 20)
261 __asm_copy_from_user_20(to, from, ret);
262 else if (n == 24)
263 __asm_copy_from_user_24(to, from, ret);
264 else
265 ret = __generic_copy_from_user(to, from, n);
266
267 return ret;
268 }
269
270 /* Ditto, don't make a switch out of this. */
271
272 static inline unsigned long
__constant_copy_to_user(void __user * to,const void * from,unsigned long n)273 __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
274 {
275 unsigned long ret = 0;
276 if (n == 0)
277 ;
278 else if (n == 1)
279 __asm_copy_to_user_1(to, from, ret);
280 else if (n == 2)
281 __asm_copy_to_user_2(to, from, ret);
282 else if (n == 3)
283 __asm_copy_to_user_3(to, from, ret);
284 else if (n == 4)
285 __asm_copy_to_user_4(to, from, ret);
286 else if (n == 5)
287 __asm_copy_to_user_5(to, from, ret);
288 else if (n == 6)
289 __asm_copy_to_user_6(to, from, ret);
290 else if (n == 7)
291 __asm_copy_to_user_7(to, from, ret);
292 else if (n == 8)
293 __asm_copy_to_user_8(to, from, ret);
294 else if (n == 9)
295 __asm_copy_to_user_9(to, from, ret);
296 else if (n == 10)
297 __asm_copy_to_user_10(to, from, ret);
298 else if (n == 11)
299 __asm_copy_to_user_11(to, from, ret);
300 else if (n == 12)
301 __asm_copy_to_user_12(to, from, ret);
302 else if (n == 13)
303 __asm_copy_to_user_13(to, from, ret);
304 else if (n == 14)
305 __asm_copy_to_user_14(to, from, ret);
306 else if (n == 15)
307 __asm_copy_to_user_15(to, from, ret);
308 else if (n == 16)
309 __asm_copy_to_user_16(to, from, ret);
310 else if (n == 20)
311 __asm_copy_to_user_20(to, from, ret);
312 else if (n == 24)
313 __asm_copy_to_user_24(to, from, ret);
314 else
315 ret = __generic_copy_to_user(to, from, n);
316
317 return ret;
318 }
319
320 /* No switch, please. */
321
322 static inline unsigned long
__constant_clear_user(void __user * to,unsigned long n)323 __constant_clear_user(void __user *to, unsigned long n)
324 {
325 unsigned long ret = 0;
326 if (n == 0)
327 ;
328 else if (n == 1)
329 __asm_clear_1(to, ret);
330 else if (n == 2)
331 __asm_clear_2(to, ret);
332 else if (n == 3)
333 __asm_clear_3(to, ret);
334 else if (n == 4)
335 __asm_clear_4(to, ret);
336 else if (n == 8)
337 __asm_clear_8(to, ret);
338 else if (n == 12)
339 __asm_clear_12(to, ret);
340 else if (n == 16)
341 __asm_clear_16(to, ret);
342 else if (n == 20)
343 __asm_clear_20(to, ret);
344 else if (n == 24)
345 __asm_clear_24(to, ret);
346 else
347 ret = __generic_clear_user(to, n);
348
349 return ret;
350 }
351
352
353 #define clear_user(to, n) \
354 (__builtin_constant_p(n) ? \
355 __constant_clear_user(to, n) : \
356 __generic_clear_user(to, n))
357
358 #define copy_from_user(to, from, n) \
359 (__builtin_constant_p(n) ? \
360 __constant_copy_from_user(to, from, n) : \
361 __generic_copy_from_user(to, from, n))
362
363 #define copy_to_user(to, from, n) \
364 (__builtin_constant_p(n) ? \
365 __constant_copy_to_user(to, from, n) : \
366 __generic_copy_to_user(to, from, n))
367
368 /* We let the __ versions of copy_from/to_user inline, because they're often
369 * used in fast paths and have only a small space overhead.
370 */
371
372 static inline unsigned long
__generic_copy_from_user_nocheck(void * to,const void __user * from,unsigned long n)373 __generic_copy_from_user_nocheck(void *to, const void __user *from,
374 unsigned long n)
375 {
376 return __copy_user_zeroing(to,from,n);
377 }
378
379 static inline unsigned long
__generic_copy_to_user_nocheck(void __user * to,const void * from,unsigned long n)380 __generic_copy_to_user_nocheck(void __user *to, const void *from,
381 unsigned long n)
382 {
383 return __copy_user(to,from,n);
384 }
385
386 static inline unsigned long
__generic_clear_user_nocheck(void __user * to,unsigned long n)387 __generic_clear_user_nocheck(void __user *to, unsigned long n)
388 {
389 return __do_clear_user(to,n);
390 }
391
392 /* without checking */
393
394 #define __copy_to_user(to,from,n) __generic_copy_to_user_nocheck((to),(from),(n))
395 #define __copy_from_user(to,from,n) __generic_copy_from_user_nocheck((to),(from),(n))
396 #define __copy_to_user_inatomic __copy_to_user
397 #define __copy_from_user_inatomic __copy_from_user
398 #define __clear_user(to,n) __generic_clear_user_nocheck((to),(n))
399
400 #define strlen_user(str) strnlen_user((str), 0x7ffffffe)
401
402 #endif /* __ASSEMBLY__ */
403
404 #endif /* _CRIS_UACCESS_H */
405