?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Kill junk from recent merge.
[linux-2.6/linux-mips.git] / include / asm-alpha / uaccess.h
blob98c446942f05e8846c1695158fdad17515ad53cc
1 #ifndef __ALPHA_UACCESS_H
2 #define __ALPHA_UACCESS_H
3
4 #include <linux/errno.h>
5 #include <linux/sched.h>
6
7
8 /*
9 * The fs value determines whether argument validity checking should be
10 * performed or not. If get_fs() == USER_DS, checking is performed, with
11 * get_fs() == KERNEL_DS, checking is bypassed.
12 *
13 * Or at least it did once upon a time. Nowadays it is a mask that
14 * defines which bits of the address space are off limits. This is a
15 * wee bit faster than the above.
16 *
17 * For historical reasons, these macros are grossly misnamed.
18 */
19
20 #define KERNEL_DS ((mm_segment_t) { 0UL })
21 #define USER_DS ((mm_segment_t) { -0x40000000000UL })
22
23 #define VERIFY_READ 0
24 #define VERIFY_WRITE 1
25
26 #define get_fs() (current->thread.fs)
27 #define get_ds() (KERNEL_DS)
28 #define set_fs(x) (current->thread.fs = (x))
29
30 #define segment_eq(a,b) ((a).seg == (b).seg)
31
32
33 /*
34 * Is a address valid? This does a straighforward calculation rather
35 * than tests.
36 *
37 * Address valid if:
38 * - "addr" doesn't have any high-bits set
39 * - AND "size" doesn't have any high-bits set
40 * - AND "addr+size" doesn't have any high-bits set
41 * - OR we are in kernel mode.
42 */
43 #define __access_ok(addr,size,segment) \
44 (((segment).seg & (addr | size | (addr+size))) == 0)
45
46 #define access_ok(type,addr,size) \
47 __access_ok(((unsigned long)(addr)),(size),get_fs())
48
49 extern inline int verify_area(int type, const void * addr, unsigned long size)
50 {
51 return access_ok(type,addr,size) ? 0 : -EFAULT;
52 }
53
54 /*
55 * These are the main single-value transfer routines. They automatically
56 * use the right size if we just have the right pointer type.
57 *
58 * As the alpha uses the same address space for kernel and user
59 * data, we can just do these as direct assignments. (Of course, the
60 * exception handling means that it's no longer "just"...)
61 *
62 * Careful to not
63 * (a) re-use the arguments for side effects (sizeof/typeof is ok)
64 * (b) require any knowledge of processes at this stage
65 */
66 #define put_user(x,ptr) \
67 __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)),get_fs())
68 #define get_user(x,ptr) \
69 __get_user_check((x),(ptr),sizeof(*(ptr)),get_fs())
70
71 /*
72 * The "__xxx" versions do not do address space checking, useful when
73 * doing multiple accesses to the same area (the programmer has to do the
74 * checks by hand with "access_ok()")
75 */
76 #define __put_user(x,ptr) \
77 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
78 #define __get_user(x,ptr) \
79 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
80
81 /*
82 * The "xxx_ret" versions return constant specified in third argument, if
83 * something bad happens. These macros can be optimized for the
84 * case of just returning from the function xxx_ret is used.
85 */
86
87 #define put_user_ret(x,ptr,ret) ({ \
88 if (put_user(x,ptr)) return ret; })
89
90 #define get_user_ret(x,ptr,ret) ({ \
91 if (get_user(x,ptr)) return ret; })
92
93 #define __put_user_ret(x,ptr,ret) ({ \
94 if (__put_user(x,ptr)) return ret; })
95
96 #define __get_user_ret(x,ptr,ret) ({ \
97 if (__get_user(x,ptr)) return ret; })
98
99 /*
100 * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to
101 * encode the bits we need for resolving the exception. See the
102 * more extensive comments with fixup_inline_exception below for
103 * more information.
104 */
105
106 extern void __get_user_unknown(void);
107
108 #define __get_user_nocheck(x,ptr,size) \
109 ({ \
110 long __gu_err = 0, __gu_val; \
111 switch (size) { \
112 case 1: __get_user_8(ptr); break; \
113 case 2: __get_user_16(ptr); break; \
114 case 4: __get_user_32(ptr); break; \
115 case 8: __get_user_64(ptr); break; \
116 default: __get_user_unknown(); break; \
117 } \
118 (x) = (__typeof__(*(ptr))) __gu_val; \
119 __gu_err; \
120 })
121
122 #define __get_user_check(x,ptr,size,segment) \
123 ({ \
124 long __gu_err = -EFAULT, __gu_val = 0; \
125 const __typeof__(*(ptr)) *__gu_addr = (ptr); \
126 if (__access_ok((long)__gu_addr,size,segment)) { \
127 __gu_err = 0; \
128 switch (size) { \
129 case 1: __get_user_8(__gu_addr); break; \
130 case 2: __get_user_16(__gu_addr); break; \
131 case 4: __get_user_32(__gu_addr); break; \
132 case 8: __get_user_64(__gu_addr); break; \
133 default: __get_user_unknown(); break; \
134 } \
135 } \
136 (x) = (__typeof__(*(ptr))) __gu_val; \
137 __gu_err; \
138 })
139
140 struct __large_struct { unsigned long buf[100]; };
141 #define __m(x) (*(struct __large_struct *)(x))
142
143 #define __get_user_64(addr) \
144 __asm__("1: ldq %0,%2\n" \
145 "2:\n" \
146 ".section __ex_table,\"a\"\n" \
147 " .gprel32 1b\n" \
148 " lda %0, 2b-1b(%1)\n" \
149 ".previous" \
150 : "=r"(__gu_val), "=r"(__gu_err) \
151 : "m"(__m(addr)), "1"(__gu_err))
152
153 #define __get_user_32(addr) \
154 __asm__("1: ldl %0,%2\n" \
155 "2:\n" \
156 ".section __ex_table,\"a\"\n" \
157 " .gprel32 1b\n" \
158 " lda %0, 2b-1b(%1)\n" \
159 ".previous" \
160 : "=r"(__gu_val), "=r"(__gu_err) \
161 : "m"(__m(addr)), "1"(__gu_err))
162
163 #ifdef __alpha_bwx__
164 /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */
165
166 #define __get_user_16(addr) \
167 __asm__("1: ldwu %0,%2\n" \
168 "2:\n" \
169 ".section __ex_table,\"a\"\n" \
170 " .gprel32 1b\n" \
171 " lda %0, 2b-1b(%1)\n" \
172 ".previous" \
173 : "=r"(__gu_val), "=r"(__gu_err) \
174 : "m"(__m(addr)), "1"(__gu_err))
175
176 #define __get_user_8(addr) \
177 __asm__("1: ldbu %0,%2\n" \
178 "2:\n" \
179 ".section __ex_table,\"a\"\n" \
180 " .gprel32 1b\n" \
181 " lda %0, 2b-1b(%1)\n" \
182 ".previous" \
183 : "=r"(__gu_val), "=r"(__gu_err) \
184 : "m"(__m(addr)), "1"(__gu_err))
185 #else
186 /* Unfortunately, we can't get an unaligned access trap for the sub-word
187 load, so we have to do a general unaligned operation. */
188
189 #define __get_user_16(addr) \
190 { \
191 long __gu_tmp; \
192 __asm__("1: ldq_u %0,0(%3)\n" \
193 "2: ldq_u %1,1(%3)\n" \
194 " extwl %0,%3,%0\n" \
195 " extwh %1,%3,%1\n" \
196 " or %0,%1,%0\n" \
197 "3:\n" \
198 ".section __ex_table,\"a\"\n" \
199 " .gprel32 1b\n" \
200 " lda %0, 3b-1b(%2)\n" \
201 " .gprel32 2b\n" \
202 " lda %0, 2b-1b(%2)\n" \
203 ".previous" \
204 : "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \
205 : "r"(addr), "2"(__gu_err)); \
206 }
207
208 #define __get_user_8(addr) \
209 __asm__("1: ldq_u %0,0(%2)\n" \
210 " extbl %0,%2,%0\n" \
211 "2:\n" \
212 ".section __ex_table,\"a\"\n" \
213 " .gprel32 1b\n" \
214 " lda %0, 2b-1b(%1)\n" \
215 ".previous" \
216 : "=&r"(__gu_val), "=r"(__gu_err) \
217 : "r"(addr), "1"(__gu_err))
218 #endif
219
220 extern void __put_user_unknown(void);
221
222 #define __put_user_nocheck(x,ptr,size) \
223 ({ \
224 long __pu_err = 0; \
225 switch (size) { \
226 case 1: __put_user_8(x,ptr); break; \
227 case 2: __put_user_16(x,ptr); break; \
228 case 4: __put_user_32(x,ptr); break; \
229 case 8: __put_user_64(x,ptr); break; \
230 default: __put_user_unknown(); break; \
231 } \
232 __pu_err; \
233 })
234
235 #define __put_user_check(x,ptr,size,segment) \
236 ({ \
237 long __pu_err = -EFAULT; \
238 __typeof__(*(ptr)) *__pu_addr = (ptr); \
239 if (__access_ok((long)__pu_addr,size,segment)) { \
240 __pu_err = 0; \
241 switch (size) { \
242 case 1: __put_user_8(x,__pu_addr); break; \
243 case 2: __put_user_16(x,__pu_addr); break; \
244 case 4: __put_user_32(x,__pu_addr); break; \
245 case 8: __put_user_64(x,__pu_addr); break; \
246 default: __put_user_unknown(); break; \
247 } \
248 } \
249 __pu_err; \
250 })
251
252 /*
253 * The "__put_user_xx()" macros tell gcc they read from memory
254 * instead of writing: this is because they do not write to
255 * any memory gcc knows about, so there are no aliasing issues
256 */
257 #define __put_user_64(x,addr) \
258 __asm__ __volatile__("1: stq %r2,%1\n" \
259 "2:\n" \
260 ".section __ex_table,\"a\"\n" \
261 " .gprel32 1b\n" \
262 " lda $31,2b-1b(%0)\n" \
263 ".previous" \
264 : "=r"(__pu_err) \
265 : "m" (__m(addr)), "rJ" (x), "0"(__pu_err))
266
267 #define __put_user_32(x,addr) \
268 __asm__ __volatile__("1: stl %r2,%1\n" \
269 "2:\n" \
270 ".section __ex_table,\"a\"\n" \
271 " .gprel32 1b\n" \
272 " lda $31,2b-1b(%0)\n" \
273 ".previous" \
274 : "=r"(__pu_err) \
275 : "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
276
277 #ifdef __alpha_bwx__
278 /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */
279
280 #define __put_user_16(x,addr) \
281 __asm__ __volatile__("1: stw %r2,%1\n" \
282 "2:\n" \
283 ".section __ex_table,\"a\"\n" \
284 " .gprel32 1b\n" \
285 " lda $31,2b-1b(%0)\n" \
286 ".previous" \
287 : "=r"(__pu_err) \
288 : "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
289
290 #define __put_user_8(x,addr) \
291 __asm__ __volatile__("1: stb %r2,%1\n" \
292 "2:\n" \
293 ".section __ex_table,\"a\"\n" \
294 " .gprel32 1b\n" \
295 " lda $31,2b-1b(%0)\n" \
296 ".previous" \
297 : "=r"(__pu_err) \
298 : "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
299 #else
300 /* Unfortunately, we can't get an unaligned access trap for the sub-word
301 write, so we have to do a general unaligned operation. */
302
303 #define __put_user_16(x,addr) \
304 { \
305 long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \
306 __asm__ __volatile__( \
307 "1: ldq_u %2,1(%5)\n" \
308 "2: ldq_u %1,0(%5)\n" \
309 " inswh %6,%5,%4\n" \
310 " inswl %6,%5,%3\n" \
311 " mskwh %2,%5,%2\n" \
312 " mskwl %1,%5,%1\n" \
313 " or %2,%4,%2\n" \
314 " or %1,%3,%1\n" \
315 "3: stq_u %2,1(%5)\n" \
316 "4: stq_u %1,0(%5)\n" \
317 "5:\n" \
318 ".section __ex_table,\"a\"\n" \
319 " .gprel32 1b\n" \
320 " lda $31, 5b-1b(%0)\n" \
321 " .gprel32 2b\n" \
322 " lda $31, 5b-2b(%0)\n" \
323 " .gprel32 3b\n" \
324 " lda $31, 5b-3b(%0)\n" \
325 " .gprel32 4b\n" \
326 " lda $31, 5b-4b(%0)\n" \
327 ".previous" \
328 : "=r"(__pu_err), "=&r"(__pu_tmp1), \
329 "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \
330 "=&r"(__pu_tmp4) \
331 : "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \
332 }
333
334 #define __put_user_8(x,addr) \
335 { \
336 long __pu_tmp1, __pu_tmp2; \
337 __asm__ __volatile__( \
338 "1: ldq_u %1,0(%4)\n" \
339 " insbl %3,%4,%2\n" \
340 " mskbl %1,%4,%1\n" \
341 " or %1,%2,%1\n" \
342 "2: stq_u %1,0(%4)\n" \
343 "3:\n" \
344 ".section __ex_table,\"a\"\n" \
345 " .gprel32 1b\n" \
346 " lda $31, 3b-1b(%0)\n" \
347 " .gprel32 2b\n" \
348 " lda $31, 3b-2b(%0)\n" \
349 ".previous" \
350 : "=r"(__pu_err), \
351 "=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \
352 : "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \
353 }
354 #endif
355
356
357 /*
358 * Complex access routines
359 */
360
361 extern void __copy_user(void);
362
363 extern inline long
364 __copy_tofrom_user_nocheck(void *to, const void *from, long len)
365 {
366 /* This little bit of silliness is to get the GP loaded for
367 a function that ordinarily wouldn't. Otherwise we could
368 have it done by the macro directly, which can be optimized
369 the linker. */
370 register void * pv __asm__("$27") = __copy_user;
371
372 register void * __cu_to __asm__("$6") = to;
373 register const void * __cu_from __asm__("$7") = from;
374 register long __cu_len __asm__("$0") = len;
375
376 __asm__ __volatile__(
377 "jsr $28,(%3),__copy_user\n\tldgp $29,0($28)"
378 : "=r" (__cu_len), "=r" (__cu_from), "=r" (__cu_to), "=r"(pv)
379 : "0" (__cu_len), "1" (__cu_from), "2" (__cu_to), "3"(pv)
380 : "$1","$2","$3","$4","$5","$28","memory");
381
382 return __cu_len;
383 }
384
385 extern inline long
386 __copy_tofrom_user(void *to, const void *from, long len, const void *validate)
387 {
388 if (__access_ok((long)validate, len, get_fs())) {
389 register void * pv __asm__("$27") = __copy_user;
390 register void * __cu_to __asm__("$6") = to;
391 register const void * __cu_from __asm__("$7") = from;
392 register long __cu_len __asm__("$0") = len;
393 __asm__ __volatile__(
394 "jsr $28,(%3),__copy_user\n\tldgp $29,0($28)"
395 : "=r"(__cu_len), "=r"(__cu_from), "=r"(__cu_to),
396 "=r" (pv)
397 : "0" (__cu_len), "1" (__cu_from), "2" (__cu_to),
398 "3" (pv)
399 : "$1","$2","$3","$4","$5","$28","memory");
400 len = __cu_len;
401 }
402 return len;
403 }
404
405 #define __copy_to_user(to,from,n) __copy_tofrom_user_nocheck((to),(from),(n))
406 #define __copy_from_user(to,from,n) __copy_tofrom_user_nocheck((to),(from),(n))
407
408 extern inline long
409 copy_to_user(void *to, const void *from, long n)
410 {
411 return __copy_tofrom_user(to, from, n, to);
412 }
413
414 extern inline long
415 copy_from_user(void *to, const void *from, long n)
416 {
417 return __copy_tofrom_user(to, from, n, from);
418 }
419
420 #define copy_to_user_ret(to,from,n,retval) ({ \
421 if (copy_to_user(to,from,n)) \
422 return retval; \
423 })
424
425 #define copy_from_user_ret(to,from,n,retval) ({ \
426 if (copy_from_user(to,from,n)) \
427 return retval; \
428 })
429
430 extern void __do_clear_user(void);
431
432 extern inline long
433 __clear_user(void *to, long len)
434 {
435 /* This little bit of silliness is to get the GP loaded for
436 a function that ordinarily wouldn't. Otherwise we could
437 have it done by the macro directly, which can be optimized
438 the linker. */
439 register void * pv __asm__("$27") = __do_clear_user;
440
441 register void * __cl_to __asm__("$6") = to;
442 register long __cl_len __asm__("$0") = len;
443 __asm__ __volatile__(
444 "jsr $28,(%2),__do_clear_user\n\tldgp $29,0($28)"
445 : "=r"(__cl_len), "=r"(__cl_to), "=r"(pv)
446 : "0"(__cl_len), "1"(__cl_to), "2"(pv)
447 : "$1","$2","$3","$4","$5","$28","memory");
448 return __cl_len;
449 }
450
451 extern inline long
452 clear_user(void *to, long len)
453 {
454 if (__access_ok((long)to, len, get_fs())) {
455 register void * pv __asm__("$27") = __do_clear_user;
456 register void * __cl_to __asm__("$6") = to;
457 register long __cl_len __asm__("$0") = len;
458 __asm__ __volatile__(
459 "jsr $28,(%2),__do_clear_user\n\tldgp $29,0($28)"
460 : "=r"(__cl_len), "=r"(__cl_to), "=r"(pv)
461 : "0"(__cl_len), "1"(__cl_to), "2"(pv)
462 : "$1","$2","$3","$4","$5","$28","memory");
463 len = __cl_len;
464 }
465 return len;
466 }
467
468 /* Returns: -EFAULT if exception before terminator, N if the entire
469 buffer filled, else strlen. */
470
471 extern long __strncpy_from_user(char *__to, const char *__from, long __to_len);
472
473 extern inline long
474 strncpy_from_user(char *to, const char *from, long n)
475 {
476 long ret = -EFAULT;
477 if (__access_ok((long)from, 0, get_fs()))
478 ret = __strncpy_from_user(to, from, n);
479 return ret;
480 }
481
482 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
483 extern long __strlen_user(const char *);
484
485 extern inline long strlen_user(const char *str)
486 {
487 return access_ok(VERIFY_READ,str,0) ? __strlen_user(str) : 0;
488 }
489
490 /* Returns: 0 if exception before NUL or reaching the supplied limit (N),
491 * a value greater than N if the limit would be exceeded, else strlen. */
492 extern long __strnlen_user(const char *, long);
493
494 extern inline long strnlen_user(const char *str, long n)
495 {
496 return access_ok(VERIFY_READ,str,0) ? __strnlen_user(str, n) : 0;
497 }
498
499 /*
500 * About the exception table:
501 *
502 * - insn is a 32-bit offset off of the kernel's or module's gp.
503 * - nextinsn is a 16-bit offset off of the faulting instruction
504 * (not off of the *next* instruction as branches are).
505 * - errreg is the register in which to place -EFAULT.
506 * - valreg is the final target register for the load sequence
507 * and will be zeroed.
508 *
509 * Either errreg or valreg may be $31, in which case nothing happens.
510 *
511 * The exception fixup information "just so happens" to be arranged
512 * as in a MEM format instruction. This lets us emit our three
513 * values like so:
514 *
515 * lda valreg, nextinsn(errreg)
516 *
517 */
518
519 struct exception_table_entry
520 {
521 signed int insn;
522 union exception_fixup {
523 unsigned unit;
524 struct {
525 signed int nextinsn : 16;
526 unsigned int errreg : 5;
527 unsigned int valreg : 5;
528 } bits;
529 } fixup;
530 };
531
532 /* Returns 0 if exception not found and fixup.unit otherwise. */
533 extern unsigned search_exception_table(unsigned long, unsigned long);
534
535 /* Returns the new pc */
536 #define fixup_exception(map_reg, fixup_unit, pc) \
537 ({ \
538 union exception_fixup __fie_fixup; \
539 __fie_fixup.unit = fixup_unit; \
540 if (__fie_fixup.bits.valreg != 31) \
541 map_reg(__fie_fixup.bits.valreg) = 0; \
542 if (__fie_fixup.bits.errreg != 31) \
543 map_reg(__fie_fixup.bits.errreg) = -EFAULT; \
544 (pc) + __fie_fixup.bits.nextinsn; \
545 })
546
547
548 #endif /* __ALPHA_UACCESS_H */
Mirror of the linux-mips.org kernel tree