1 /* MN10300 userspace access functions
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11 #ifndef _ASM_UACCESS_H
12 #define _ASM_UACCESS_H
13
14 /*
15 * User space memory access functions
16 */
17 #include <linux/thread_info.h>
18 #include <linux/kernel.h>
19 #include <asm/page.h>
20 #include <asm/errno.h>
21
22 #define VERIFY_READ 0
23 #define VERIFY_WRITE 1
24
25 /*
26 * The fs value determines whether argument validity checking should be
27 * performed or not. If get_fs() == USER_DS, checking is performed, with
28 * get_fs() == KERNEL_DS, checking is bypassed.
29 *
30 * For historical reasons, these macros are grossly misnamed.
31 */
32 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
33
34 #define KERNEL_XDS MAKE_MM_SEG(0xBFFFFFFF)
35 #define KERNEL_DS MAKE_MM_SEG(0x9FFFFFFF)
36 #define USER_DS MAKE_MM_SEG(TASK_SIZE)
37
38 #define get_ds() (KERNEL_DS)
39 #define get_fs() (current_thread_info()->addr_limit)
40 #define set_fs(x) (current_thread_info()->addr_limit = (x))
41 #define __kernel_ds_p() (current_thread_info()->addr_limit.seg == 0x9FFFFFFF)
42
43 #define segment_eq(a, b) ((a).seg == (b).seg)
44
45 #define __addr_ok(addr) \
46 ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
47
48 /*
49 * check that a range of addresses falls within the current address limit
50 */
___range_ok(unsigned long addr,unsigned int size)51 static inline int ___range_ok(unsigned long addr, unsigned int size)
52 {
53 int flag = 1, tmp;
54
55 asm(" add %3,%1 \n" /* set C-flag if addr + size > 4Gb */
56 " bcs 0f \n"
57 " cmp %4,%1 \n" /* jump if addr+size>limit (error) */
58 " bhi 0f \n"
59 " clr %0 \n" /* mark okay */
60 "0: \n"
61 : "=r"(flag), "=&r"(tmp)
62 : "1"(addr), "ir"(size),
63 "r"(current_thread_info()->addr_limit.seg), "0"(flag)
64 : "cc"
65 );
66
67 return flag;
68 }
69
70 #define __range_ok(addr, size) ___range_ok((unsigned long)(addr), (u32)(size))
71
72 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
73 #define __access_ok(addr, size) (__range_ok((addr), (size)) == 0)
74
verify_area(int type,const void * addr,unsigned long size)75 static inline int verify_area(int type, const void *addr, unsigned long size)
76 {
77 return access_ok(type, addr, size) ? 0 : -EFAULT;
78 }
79
80
81 /*
82 * The exception table consists of pairs of addresses: the first is the
83 * address of an instruction that is allowed to fault, and the second is
84 * the address at which the program should continue. No registers are
85 * modified, so it is entirely up to the continuation code to figure out
86 * what to do.
87 *
88 * All the routines below use bits of fixup code that are out of line
89 * with the main instruction path. This means when everything is well,
90 * we don't even have to jump over them. Further, they do not intrude
91 * on our cache or tlb entries.
92 */
93
94 struct exception_table_entry
95 {
96 unsigned long insn, fixup;
97 };
98
99 /* Returns 0 if exception not found and fixup otherwise. */
100 extern int fixup_exception(struct pt_regs *regs);
101
102 #define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr)))
103 #define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
104
105 /*
106 * The "__xxx" versions do not do address space checking, useful when
107 * doing multiple accesses to the same area (the user has to do the
108 * checks by hand with "access_ok()")
109 */
110 #define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
111 #define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
112
113 /*
114 * The "xxx_ret" versions return constant specified in third argument, if
115 * something bad happens. These macros can be optimized for the
116 * case of just returning from the function xxx_ret is used.
117 */
118
119 #define put_user_ret(x, ptr, ret) \
120 ({ if (put_user((x), (ptr))) return (ret); })
121 #define get_user_ret(x, ptr, ret) \
122 ({ if (get_user((x), (ptr))) return (ret); })
123 #define __put_user_ret(x, ptr, ret) \
124 ({ if (__put_user((x), (ptr))) return (ret); })
125 #define __get_user_ret(x, ptr, ret) \
126 ({ if (__get_user((x), (ptr))) return (ret); })
127
128 struct __large_struct { unsigned long buf[100]; };
129 #define __m(x) (*(struct __large_struct *)(x))
130
131 #define __get_user_nocheck(x, ptr, size) \
132 ({ \
133 unsigned long __gu_addr; \
134 int __gu_err; \
135 __gu_addr = (unsigned long) (ptr); \
136 switch (size) { \
137 case 1: { \
138 unsigned char __gu_val; \
139 __get_user_asm("bu"); \
140 (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
141 break; \
142 } \
143 case 2: { \
144 unsigned short __gu_val; \
145 __get_user_asm("hu"); \
146 (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
147 break; \
148 } \
149 case 4: { \
150 unsigned int __gu_val; \
151 __get_user_asm(""); \
152 (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
153 break; \
154 } \
155 default: \
156 __get_user_unknown(); \
157 break; \
158 } \
159 __gu_err; \
160 })
161
162 #define __get_user_check(x, ptr, size) \
163 ({ \
164 const __typeof__(ptr) __guc_ptr = (ptr); \
165 int _e; \
166 if (likely(__access_ok((unsigned long) __guc_ptr, (size)))) \
167 _e = __get_user_nocheck((x), __guc_ptr, (size)); \
168 else { \
169 _e = -EFAULT; \
170 (x) = (__typeof__(x))0; \
171 } \
172 _e; \
173 })
174
175 #define __get_user_asm(INSN) \
176 ({ \
177 asm volatile( \
178 "1:\n" \
179 " mov"INSN" %2,%1\n" \
180 " mov 0,%0\n" \
181 "2:\n" \
182 " .section .fixup,\"ax\"\n" \
183 "3:\n\t" \
184 " mov %3,%0\n" \
185 " jmp 2b\n" \
186 " .previous\n" \
187 " .section __ex_table,\"a\"\n" \
188 " .balign 4\n" \
189 " .long 1b, 3b\n" \
190 " .previous" \
191 : "=&r" (__gu_err), "=&r" (__gu_val) \
192 : "m" (__m(__gu_addr)), "i" (-EFAULT)); \
193 })
194
195 extern int __get_user_unknown(void);
196
197 #define __put_user_nocheck(x, ptr, size) \
198 ({ \
199 union { \
200 __typeof__(*(ptr)) val; \
201 u32 bits[2]; \
202 } __pu_val; \
203 unsigned long __pu_addr; \
204 int __pu_err; \
205 __pu_val.val = (x); \
206 __pu_addr = (unsigned long) (ptr); \
207 switch (size) { \
208 case 1: __put_user_asm("bu"); break; \
209 case 2: __put_user_asm("hu"); break; \
210 case 4: __put_user_asm("" ); break; \
211 case 8: __put_user_asm8(); break; \
212 default: __pu_err = __put_user_unknown(); break; \
213 } \
214 __pu_err; \
215 })
216
217 #define __put_user_check(x, ptr, size) \
218 ({ \
219 union { \
220 __typeof__(*(ptr)) val; \
221 u32 bits[2]; \
222 } __pu_val; \
223 unsigned long __pu_addr; \
224 int __pu_err; \
225 __pu_val.val = (x); \
226 __pu_addr = (unsigned long) (ptr); \
227 if (likely(__access_ok(__pu_addr, size))) { \
228 switch (size) { \
229 case 1: __put_user_asm("bu"); break; \
230 case 2: __put_user_asm("hu"); break; \
231 case 4: __put_user_asm("" ); break; \
232 case 8: __put_user_asm8(); break; \
233 default: __pu_err = __put_user_unknown(); break; \
234 } \
235 } \
236 else { \
237 __pu_err = -EFAULT; \
238 } \
239 __pu_err; \
240 })
241
242 #define __put_user_asm(INSN) \
243 ({ \
244 asm volatile( \
245 "1:\n" \
246 " mov"INSN" %1,%2\n" \
247 " mov 0,%0\n" \
248 "2:\n" \
249 " .section .fixup,\"ax\"\n" \
250 "3:\n" \
251 " mov %3,%0\n" \
252 " jmp 2b\n" \
253 " .previous\n" \
254 " .section __ex_table,\"a\"\n" \
255 " .balign 4\n" \
256 " .long 1b, 3b\n" \
257 " .previous" \
258 : "=&r" (__pu_err) \
259 : "r" (__pu_val.val), "m" (__m(__pu_addr)), \
260 "i" (-EFAULT) \
261 ); \
262 })
263
264 #define __put_user_asm8() \
265 ({ \
266 asm volatile( \
267 "1: mov %1,%3 \n" \
268 "2: mov %2,%4 \n" \
269 " mov 0,%0 \n" \
270 "3: \n" \
271 " .section .fixup,\"ax\" \n" \
272 "4: \n" \
273 " mov %5,%0 \n" \
274 " jmp 3b \n" \
275 " .previous \n" \
276 " .section __ex_table,\"a\"\n" \
277 " .balign 4 \n" \
278 " .long 1b, 4b \n" \
279 " .long 2b, 4b \n" \
280 " .previous \n" \
281 : "=&r" (__pu_err) \
282 : "r" (__pu_val.bits[0]), "r" (__pu_val.bits[1]), \
283 "m" (__m(__pu_addr)), "m" (__m(__pu_addr+4)), \
284 "i" (-EFAULT) \
285 ); \
286 })
287
288 extern int __put_user_unknown(void);
289
290
291 /*
292 * Copy To/From Userspace
293 */
294 /* Generic arbitrary sized copy. */
295 #define __copy_user(to, from, size) \
296 do { \
297 if (size) { \
298 void *__to = to; \
299 const void *__from = from; \
300 int w; \
301 asm volatile( \
302 "0: movbu (%0),%3;\n" \
303 "1: movbu %3,(%1);\n" \
304 " inc %0;\n" \
305 " inc %1;\n" \
306 " add -1,%2;\n" \
307 " bne 0b;\n" \
308 "2:\n" \
309 " .section .fixup,\"ax\"\n" \
310 "3: jmp 2b\n" \
311 " .previous\n" \
312 " .section __ex_table,\"a\"\n" \
313 " .balign 4\n" \
314 " .long 0b,3b\n" \
315 " .long 1b,3b\n" \
316 " .previous\n" \
317 : "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
318 : "0"(__from), "1"(__to), "2"(size) \
319 : "cc", "memory"); \
320 } \
321 } while (0)
322
323 #define __copy_user_zeroing(to, from, size) \
324 do { \
325 if (size) { \
326 void *__to = to; \
327 const void *__from = from; \
328 int w; \
329 asm volatile( \
330 "0: movbu (%0),%3;\n" \
331 "1: movbu %3,(%1);\n" \
332 " inc %0;\n" \
333 " inc %1;\n" \
334 " add -1,%2;\n" \
335 " bne 0b;\n" \
336 "2:\n" \
337 " .section .fixup,\"ax\"\n" \
338 "3:\n" \
339 " mov %2,%0\n" \
340 " clr %3\n" \
341 "4: movbu %3,(%1);\n" \
342 " inc %1;\n" \
343 " add -1,%2;\n" \
344 " bne 4b;\n" \
345 " mov %0,%2\n" \
346 " jmp 2b\n" \
347 " .previous\n" \
348 " .section __ex_table,\"a\"\n" \
349 " .balign 4\n" \
350 " .long 0b,3b\n" \
351 " .long 1b,3b\n" \
352 " .previous\n" \
353 : "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
354 : "0"(__from), "1"(__to), "2"(size) \
355 : "cc", "memory"); \
356 } \
357 } while (0)
358
359 /* We let the __ versions of copy_from/to_user inline, because they're often
360 * used in fast paths and have only a small space overhead.
361 */
362 static inline
__generic_copy_from_user_nocheck(void * to,const void * from,unsigned long n)363 unsigned long __generic_copy_from_user_nocheck(void *to, const void *from,
364 unsigned long n)
365 {
366 __copy_user_zeroing(to, from, n);
367 return n;
368 }
369
370 static inline
__generic_copy_to_user_nocheck(void * to,const void * from,unsigned long n)371 unsigned long __generic_copy_to_user_nocheck(void *to, const void *from,
372 unsigned long n)
373 {
374 __copy_user(to, from, n);
375 return n;
376 }
377
378
379 #if 0
380 #error "don't use - these macros don't increment to & from pointers"
381 /* Optimize just a little bit when we know the size of the move. */
382 #define __constant_copy_user(to, from, size) \
383 do { \
384 asm volatile( \
385 " mov %0,a0;\n" \
386 "0: movbu (%1),d3;\n" \
387 "1: movbu d3,(%2);\n" \
388 " add -1,a0;\n" \
389 " bne 0b;\n" \
390 "2:;" \
391 ".section .fixup,\"ax\"\n" \
392 "3: jmp 2b\n" \
393 ".previous\n" \
394 ".section __ex_table,\"a\"\n" \
395 " .balign 4\n" \
396 " .long 0b,3b\n" \
397 " .long 1b,3b\n" \
398 ".previous" \
399 : \
400 : "d"(size), "d"(to), "d"(from) \
401 : "d3", "a0"); \
402 } while (0)
403
404 /* Optimize just a little bit when we know the size of the move. */
405 #define __constant_copy_user_zeroing(to, from, size) \
406 do { \
407 asm volatile( \
408 " mov %0,a0;\n" \
409 "0: movbu (%1),d3;\n" \
410 "1: movbu d3,(%2);\n" \
411 " add -1,a0;\n" \
412 " bne 0b;\n" \
413 "2:;" \
414 ".section .fixup,\"ax\"\n" \
415 "3: jmp 2b\n" \
416 ".previous\n" \
417 ".section __ex_table,\"a\"\n" \
418 " .balign 4\n" \
419 " .long 0b,3b\n" \
420 " .long 1b,3b\n" \
421 ".previous" \
422 : \
423 : "d"(size), "d"(to), "d"(from) \
424 : "d3", "a0"); \
425 } while (0)
426
427 static inline
428 unsigned long __constant_copy_to_user(void *to, const void *from,
429 unsigned long n)
430 {
431 if (access_ok(VERIFY_WRITE, to, n))
432 __constant_copy_user(to, from, n);
433 return n;
434 }
435
436 static inline
437 unsigned long __constant_copy_from_user(void *to, const void *from,
438 unsigned long n)
439 {
440 if (access_ok(VERIFY_READ, from, n))
441 __constant_copy_user_zeroing(to, from, n);
442 return n;
443 }
444
445 static inline
446 unsigned long __constant_copy_to_user_nocheck(void *to, const void *from,
447 unsigned long n)
448 {
449 __constant_copy_user(to, from, n);
450 return n;
451 }
452
453 static inline
454 unsigned long __constant_copy_from_user_nocheck(void *to, const void *from,
455 unsigned long n)
456 {
457 __constant_copy_user_zeroing(to, from, n);
458 return n;
459 }
460 #endif
461
462 extern unsigned long __generic_copy_to_user(void __user *, const void *,
463 unsigned long);
464 extern unsigned long __generic_copy_from_user(void *, const void __user *,
465 unsigned long);
466
467 #define __copy_to_user_inatomic(to, from, n) \
468 __generic_copy_to_user_nocheck((to), (from), (n))
469 #define __copy_from_user_inatomic(to, from, n) \
470 __generic_copy_from_user_nocheck((to), (from), (n))
471
472 #define __copy_to_user(to, from, n) \
473 ({ \
474 might_sleep(); \
475 __copy_to_user_inatomic((to), (from), (n)); \
476 })
477
478 #define __copy_from_user(to, from, n) \
479 ({ \
480 might_sleep(); \
481 __copy_from_user_inatomic((to), (from), (n)); \
482 })
483
484
485 #define copy_to_user(to, from, n) __generic_copy_to_user((to), (from), (n))
486 #define copy_from_user(to, from, n) __generic_copy_from_user((to), (from), (n))
487
488 extern long strncpy_from_user(char *dst, const char __user *src, long count);
489 extern long __strncpy_from_user(char *dst, const char __user *src, long count);
490 extern long strnlen_user(const char __user *str, long n);
491 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
492 extern unsigned long clear_user(void __user *mem, unsigned long len);
493 extern unsigned long __clear_user(void __user *mem, unsigned long len);
494
495 #endif /* _ASM_UACCESS_H */
496