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1da177e4 LT |
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_info()->addr_limit) | |
27 | #define get_ds() (KERNEL_DS) | |
28 | #define set_fs(x) (current_thread_info()->addr_limit = (x)) | |
29 | ||
30 | #define segment_eq(a,b) ((a).seg == (b).seg) | |
31 | ||
32 | /* | |
33 | * Is a address valid? This does a straightforward calculation rather | |
34 | * than tests. | |
35 | * | |
36 | * Address valid if: | |
37 | * - "addr" doesn't have any high-bits set | |
38 | * - AND "size" doesn't have any high-bits set | |
39 | * - AND "addr+size" doesn't have any high-bits set | |
40 | * - OR we are in kernel mode. | |
41 | */ | |
42 | #define __access_ok(addr,size,segment) \ | |
43 | (((segment).seg & (addr | size | (addr+size))) == 0) | |
44 | ||
45 | #define access_ok(type,addr,size) \ | |
46 | ({ \ | |
47 | __chk_user_ptr(addr); \ | |
48 | __access_ok(((unsigned long)(addr)),(size),get_fs()); \ | |
49 | }) | |
50 | ||
1da177e4 LT |
51 | /* |
52 | * These are the main single-value transfer routines. They automatically | |
53 | * use the right size if we just have the right pointer type. | |
54 | * | |
55 | * As the alpha uses the same address space for kernel and user | |
56 | * data, we can just do these as direct assignments. (Of course, the | |
57 | * exception handling means that it's no longer "just"...) | |
58 | * | |
59 | * Careful to not | |
60 | * (a) re-use the arguments for side effects (sizeof/typeof is ok) | |
61 | * (b) require any knowledge of processes at this stage | |
62 | */ | |
63 | #define put_user(x,ptr) \ | |
64 | __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)),get_fs()) | |
65 | #define get_user(x,ptr) \ | |
66 | __get_user_check((x),(ptr),sizeof(*(ptr)),get_fs()) | |
67 | ||
68 | /* | |
69 | * The "__xxx" versions do not do address space checking, useful when | |
70 | * doing multiple accesses to the same area (the programmer has to do the | |
71 | * checks by hand with "access_ok()") | |
72 | */ | |
73 | #define __put_user(x,ptr) \ | |
74 | __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) | |
75 | #define __get_user(x,ptr) \ | |
76 | __get_user_nocheck((x),(ptr),sizeof(*(ptr))) | |
77 | ||
78 | /* | |
79 | * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to | |
80 | * encode the bits we need for resolving the exception. See the | |
81 | * more extensive comments with fixup_inline_exception below for | |
82 | * more information. | |
83 | */ | |
84 | ||
85 | extern void __get_user_unknown(void); | |
86 | ||
87 | #define __get_user_nocheck(x,ptr,size) \ | |
88 | ({ \ | |
89 | long __gu_err = 0; \ | |
90 | unsigned long __gu_val; \ | |
91 | __chk_user_ptr(ptr); \ | |
92 | switch (size) { \ | |
93 | case 1: __get_user_8(ptr); break; \ | |
94 | case 2: __get_user_16(ptr); break; \ | |
95 | case 4: __get_user_32(ptr); break; \ | |
96 | case 8: __get_user_64(ptr); break; \ | |
97 | default: __get_user_unknown(); break; \ | |
98 | } \ | |
99 | (x) = (__typeof__(*(ptr))) __gu_val; \ | |
100 | __gu_err; \ | |
101 | }) | |
102 | ||
103 | #define __get_user_check(x,ptr,size,segment) \ | |
104 | ({ \ | |
105 | long __gu_err = -EFAULT; \ | |
106 | unsigned long __gu_val = 0; \ | |
107 | const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ | |
108 | if (__access_ok((unsigned long)__gu_addr,size,segment)) { \ | |
109 | __gu_err = 0; \ | |
110 | switch (size) { \ | |
111 | case 1: __get_user_8(__gu_addr); break; \ | |
112 | case 2: __get_user_16(__gu_addr); break; \ | |
113 | case 4: __get_user_32(__gu_addr); break; \ | |
114 | case 8: __get_user_64(__gu_addr); break; \ | |
115 | default: __get_user_unknown(); break; \ | |
116 | } \ | |
117 | } \ | |
118 | (x) = (__typeof__(*(ptr))) __gu_val; \ | |
119 | __gu_err; \ | |
120 | }) | |
121 | ||
122 | struct __large_struct { unsigned long buf[100]; }; | |
123 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
124 | ||
125 | #define __get_user_64(addr) \ | |
126 | __asm__("1: ldq %0,%2\n" \ | |
127 | "2:\n" \ | |
128 | ".section __ex_table,\"a\"\n" \ | |
129 | " .long 1b - .\n" \ | |
130 | " lda %0, 2b-1b(%1)\n" \ | |
131 | ".previous" \ | |
132 | : "=r"(__gu_val), "=r"(__gu_err) \ | |
133 | : "m"(__m(addr)), "1"(__gu_err)) | |
134 | ||
135 | #define __get_user_32(addr) \ | |
136 | __asm__("1: ldl %0,%2\n" \ | |
137 | "2:\n" \ | |
138 | ".section __ex_table,\"a\"\n" \ | |
139 | " .long 1b - .\n" \ | |
140 | " lda %0, 2b-1b(%1)\n" \ | |
141 | ".previous" \ | |
142 | : "=r"(__gu_val), "=r"(__gu_err) \ | |
143 | : "m"(__m(addr)), "1"(__gu_err)) | |
144 | ||
145 | #ifdef __alpha_bwx__ | |
146 | /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ | |
147 | ||
148 | #define __get_user_16(addr) \ | |
149 | __asm__("1: ldwu %0,%2\n" \ | |
150 | "2:\n" \ | |
151 | ".section __ex_table,\"a\"\n" \ | |
152 | " .long 1b - .\n" \ | |
153 | " lda %0, 2b-1b(%1)\n" \ | |
154 | ".previous" \ | |
155 | : "=r"(__gu_val), "=r"(__gu_err) \ | |
156 | : "m"(__m(addr)), "1"(__gu_err)) | |
157 | ||
158 | #define __get_user_8(addr) \ | |
159 | __asm__("1: ldbu %0,%2\n" \ | |
160 | "2:\n" \ | |
161 | ".section __ex_table,\"a\"\n" \ | |
162 | " .long 1b - .\n" \ | |
163 | " lda %0, 2b-1b(%1)\n" \ | |
164 | ".previous" \ | |
165 | : "=r"(__gu_val), "=r"(__gu_err) \ | |
166 | : "m"(__m(addr)), "1"(__gu_err)) | |
167 | #else | |
168 | /* Unfortunately, we can't get an unaligned access trap for the sub-word | |
169 | load, so we have to do a general unaligned operation. */ | |
170 | ||
171 | #define __get_user_16(addr) \ | |
172 | { \ | |
173 | long __gu_tmp; \ | |
174 | __asm__("1: ldq_u %0,0(%3)\n" \ | |
175 | "2: ldq_u %1,1(%3)\n" \ | |
176 | " extwl %0,%3,%0\n" \ | |
177 | " extwh %1,%3,%1\n" \ | |
178 | " or %0,%1,%0\n" \ | |
179 | "3:\n" \ | |
180 | ".section __ex_table,\"a\"\n" \ | |
181 | " .long 1b - .\n" \ | |
182 | " lda %0, 3b-1b(%2)\n" \ | |
183 | " .long 2b - .\n" \ | |
184 | " lda %0, 3b-2b(%2)\n" \ | |
185 | ".previous" \ | |
186 | : "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \ | |
187 | : "r"(addr), "2"(__gu_err)); \ | |
188 | } | |
189 | ||
190 | #define __get_user_8(addr) \ | |
191 | __asm__("1: ldq_u %0,0(%2)\n" \ | |
192 | " extbl %0,%2,%0\n" \ | |
193 | "2:\n" \ | |
194 | ".section __ex_table,\"a\"\n" \ | |
195 | " .long 1b - .\n" \ | |
196 | " lda %0, 2b-1b(%1)\n" \ | |
197 | ".previous" \ | |
198 | : "=&r"(__gu_val), "=r"(__gu_err) \ | |
199 | : "r"(addr), "1"(__gu_err)) | |
200 | #endif | |
201 | ||
202 | extern void __put_user_unknown(void); | |
203 | ||
204 | #define __put_user_nocheck(x,ptr,size) \ | |
205 | ({ \ | |
206 | long __pu_err = 0; \ | |
207 | __chk_user_ptr(ptr); \ | |
208 | switch (size) { \ | |
209 | case 1: __put_user_8(x,ptr); break; \ | |
210 | case 2: __put_user_16(x,ptr); break; \ | |
211 | case 4: __put_user_32(x,ptr); break; \ | |
212 | case 8: __put_user_64(x,ptr); break; \ | |
213 | default: __put_user_unknown(); break; \ | |
214 | } \ | |
215 | __pu_err; \ | |
216 | }) | |
217 | ||
218 | #define __put_user_check(x,ptr,size,segment) \ | |
219 | ({ \ | |
220 | long __pu_err = -EFAULT; \ | |
221 | __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ | |
222 | if (__access_ok((unsigned long)__pu_addr,size,segment)) { \ | |
223 | __pu_err = 0; \ | |
224 | switch (size) { \ | |
225 | case 1: __put_user_8(x,__pu_addr); break; \ | |
226 | case 2: __put_user_16(x,__pu_addr); break; \ | |
227 | case 4: __put_user_32(x,__pu_addr); break; \ | |
228 | case 8: __put_user_64(x,__pu_addr); break; \ | |
229 | default: __put_user_unknown(); break; \ | |
230 | } \ | |
231 | } \ | |
232 | __pu_err; \ | |
233 | }) | |
234 | ||
235 | /* | |
236 | * The "__put_user_xx()" macros tell gcc they read from memory | |
237 | * instead of writing: this is because they do not write to | |
238 | * any memory gcc knows about, so there are no aliasing issues | |
239 | */ | |
240 | #define __put_user_64(x,addr) \ | |
241 | __asm__ __volatile__("1: stq %r2,%1\n" \ | |
242 | "2:\n" \ | |
243 | ".section __ex_table,\"a\"\n" \ | |
244 | " .long 1b - .\n" \ | |
245 | " lda $31,2b-1b(%0)\n" \ | |
246 | ".previous" \ | |
247 | : "=r"(__pu_err) \ | |
248 | : "m" (__m(addr)), "rJ" (x), "0"(__pu_err)) | |
249 | ||
250 | #define __put_user_32(x,addr) \ | |
251 | __asm__ __volatile__("1: stl %r2,%1\n" \ | |
252 | "2:\n" \ | |
253 | ".section __ex_table,\"a\"\n" \ | |
254 | " .long 1b - .\n" \ | |
255 | " lda $31,2b-1b(%0)\n" \ | |
256 | ".previous" \ | |
257 | : "=r"(__pu_err) \ | |
258 | : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) | |
259 | ||
260 | #ifdef __alpha_bwx__ | |
261 | /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ | |
262 | ||
263 | #define __put_user_16(x,addr) \ | |
264 | __asm__ __volatile__("1: stw %r2,%1\n" \ | |
265 | "2:\n" \ | |
266 | ".section __ex_table,\"a\"\n" \ | |
267 | " .long 1b - .\n" \ | |
268 | " lda $31,2b-1b(%0)\n" \ | |
269 | ".previous" \ | |
270 | : "=r"(__pu_err) \ | |
271 | : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) | |
272 | ||
273 | #define __put_user_8(x,addr) \ | |
274 | __asm__ __volatile__("1: stb %r2,%1\n" \ | |
275 | "2:\n" \ | |
276 | ".section __ex_table,\"a\"\n" \ | |
277 | " .long 1b - .\n" \ | |
278 | " lda $31,2b-1b(%0)\n" \ | |
279 | ".previous" \ | |
280 | : "=r"(__pu_err) \ | |
281 | : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) | |
282 | #else | |
283 | /* Unfortunately, we can't get an unaligned access trap for the sub-word | |
284 | write, so we have to do a general unaligned operation. */ | |
285 | ||
286 | #define __put_user_16(x,addr) \ | |
287 | { \ | |
288 | long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \ | |
289 | __asm__ __volatile__( \ | |
290 | "1: ldq_u %2,1(%5)\n" \ | |
291 | "2: ldq_u %1,0(%5)\n" \ | |
292 | " inswh %6,%5,%4\n" \ | |
293 | " inswl %6,%5,%3\n" \ | |
294 | " mskwh %2,%5,%2\n" \ | |
295 | " mskwl %1,%5,%1\n" \ | |
296 | " or %2,%4,%2\n" \ | |
297 | " or %1,%3,%1\n" \ | |
298 | "3: stq_u %2,1(%5)\n" \ | |
299 | "4: stq_u %1,0(%5)\n" \ | |
300 | "5:\n" \ | |
301 | ".section __ex_table,\"a\"\n" \ | |
302 | " .long 1b - .\n" \ | |
303 | " lda $31, 5b-1b(%0)\n" \ | |
304 | " .long 2b - .\n" \ | |
305 | " lda $31, 5b-2b(%0)\n" \ | |
306 | " .long 3b - .\n" \ | |
307 | " lda $31, 5b-3b(%0)\n" \ | |
308 | " .long 4b - .\n" \ | |
309 | " lda $31, 5b-4b(%0)\n" \ | |
310 | ".previous" \ | |
311 | : "=r"(__pu_err), "=&r"(__pu_tmp1), \ | |
312 | "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \ | |
313 | "=&r"(__pu_tmp4) \ | |
314 | : "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \ | |
315 | } | |
316 | ||
317 | #define __put_user_8(x,addr) \ | |
318 | { \ | |
319 | long __pu_tmp1, __pu_tmp2; \ | |
320 | __asm__ __volatile__( \ | |
321 | "1: ldq_u %1,0(%4)\n" \ | |
322 | " insbl %3,%4,%2\n" \ | |
323 | " mskbl %1,%4,%1\n" \ | |
324 | " or %1,%2,%1\n" \ | |
325 | "2: stq_u %1,0(%4)\n" \ | |
326 | "3:\n" \ | |
327 | ".section __ex_table,\"a\"\n" \ | |
328 | " .long 1b - .\n" \ | |
329 | " lda $31, 3b-1b(%0)\n" \ | |
330 | " .long 2b - .\n" \ | |
331 | " lda $31, 3b-2b(%0)\n" \ | |
332 | ".previous" \ | |
333 | : "=r"(__pu_err), \ | |
334 | "=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \ | |
335 | : "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \ | |
336 | } | |
337 | #endif | |
338 | ||
339 | ||
340 | /* | |
341 | * Complex access routines | |
342 | */ | |
343 | ||
344 | /* This little bit of silliness is to get the GP loaded for a function | |
345 | that ordinarily wouldn't. Otherwise we could have it done by the macro | |
346 | directly, which can be optimized the linker. */ | |
347 | #ifdef MODULE | |
348 | #define __module_address(sym) "r"(sym), | |
349 | #define __module_call(ra, arg, sym) "jsr $" #ra ",(%" #arg ")," #sym | |
350 | #else | |
351 | #define __module_address(sym) | |
352 | #define __module_call(ra, arg, sym) "bsr $" #ra "," #sym " !samegp" | |
353 | #endif | |
354 | ||
355 | extern void __copy_user(void); | |
356 | ||
357 | extern inline long | |
358 | __copy_tofrom_user_nocheck(void *to, const void *from, long len) | |
359 | { | |
360 | register void * __cu_to __asm__("$6") = to; | |
361 | register const void * __cu_from __asm__("$7") = from; | |
362 | register long __cu_len __asm__("$0") = len; | |
363 | ||
364 | __asm__ __volatile__( | |
365 | __module_call(28, 3, __copy_user) | |
366 | : "=r" (__cu_len), "=r" (__cu_from), "=r" (__cu_to) | |
367 | : __module_address(__copy_user) | |
368 | "0" (__cu_len), "1" (__cu_from), "2" (__cu_to) | |
369 | : "$1","$2","$3","$4","$5","$28","memory"); | |
370 | ||
371 | return __cu_len; | |
372 | } | |
373 | ||
374 | extern inline long | |
375 | __copy_tofrom_user(void *to, const void *from, long len, const void __user *validate) | |
376 | { | |
377 | if (__access_ok((unsigned long)validate, len, get_fs())) | |
378 | len = __copy_tofrom_user_nocheck(to, from, len); | |
379 | return len; | |
380 | } | |
381 | ||
382 | #define __copy_to_user(to,from,n) \ | |
383 | ({ \ | |
384 | __chk_user_ptr(to); \ | |
385 | __copy_tofrom_user_nocheck((__force void *)(to),(from),(n)); \ | |
386 | }) | |
387 | #define __copy_from_user(to,from,n) \ | |
388 | ({ \ | |
389 | __chk_user_ptr(from); \ | |
390 | __copy_tofrom_user_nocheck((to),(__force void *)(from),(n)); \ | |
391 | }) | |
392 | ||
393 | #define __copy_to_user_inatomic __copy_to_user | |
394 | #define __copy_from_user_inatomic __copy_from_user | |
395 | ||
396 | ||
397 | extern inline long | |
398 | copy_to_user(void __user *to, const void *from, long n) | |
399 | { | |
400 | return __copy_tofrom_user((__force void *)to, from, n, to); | |
401 | } | |
402 | ||
403 | extern inline long | |
404 | copy_from_user(void *to, const void __user *from, long n) | |
405 | { | |
406 | return __copy_tofrom_user(to, (__force void *)from, n, from); | |
407 | } | |
408 | ||
409 | extern void __do_clear_user(void); | |
410 | ||
411 | extern inline long | |
412 | __clear_user(void __user *to, long len) | |
413 | { | |
414 | register void __user * __cl_to __asm__("$6") = to; | |
415 | register long __cl_len __asm__("$0") = len; | |
416 | __asm__ __volatile__( | |
417 | __module_call(28, 2, __do_clear_user) | |
418 | : "=r"(__cl_len), "=r"(__cl_to) | |
419 | : __module_address(__do_clear_user) | |
420 | "0"(__cl_len), "1"(__cl_to) | |
421 | : "$1","$2","$3","$4","$5","$28","memory"); | |
422 | return __cl_len; | |
423 | } | |
424 | ||
425 | extern inline long | |
426 | clear_user(void __user *to, long len) | |
427 | { | |
428 | if (__access_ok((unsigned long)to, len, get_fs())) | |
429 | len = __clear_user(to, len); | |
430 | return len; | |
431 | } | |
432 | ||
433 | #undef __module_address | |
434 | #undef __module_call | |
435 | ||
436 | /* Returns: -EFAULT if exception before terminator, N if the entire | |
437 | buffer filled, else strlen. */ | |
438 | ||
439 | extern long __strncpy_from_user(char *__to, const char __user *__from, long __to_len); | |
440 | ||
441 | extern inline long | |
442 | strncpy_from_user(char *to, const char __user *from, long n) | |
443 | { | |
444 | long ret = -EFAULT; | |
445 | if (__access_ok((unsigned long)from, 0, get_fs())) | |
446 | ret = __strncpy_from_user(to, from, n); | |
447 | return ret; | |
448 | } | |
449 | ||
450 | /* Returns: 0 if bad, string length+1 (memory size) of string if ok */ | |
451 | extern long __strlen_user(const char __user *); | |
452 | ||
453 | extern inline long strlen_user(const char __user *str) | |
454 | { | |
455 | return access_ok(VERIFY_READ,str,0) ? __strlen_user(str) : 0; | |
456 | } | |
457 | ||
458 | /* Returns: 0 if exception before NUL or reaching the supplied limit (N), | |
459 | * a value greater than N if the limit would be exceeded, else strlen. */ | |
460 | extern long __strnlen_user(const char __user *, long); | |
461 | ||
462 | extern inline long strnlen_user(const char __user *str, long n) | |
463 | { | |
464 | return access_ok(VERIFY_READ,str,0) ? __strnlen_user(str, n) : 0; | |
465 | } | |
466 | ||
467 | /* | |
468 | * About the exception table: | |
469 | * | |
470 | * - insn is a 32-bit pc-relative offset from the faulting insn. | |
471 | * - nextinsn is a 16-bit offset off of the faulting instruction | |
472 | * (not off of the *next* instruction as branches are). | |
473 | * - errreg is the register in which to place -EFAULT. | |
474 | * - valreg is the final target register for the load sequence | |
475 | * and will be zeroed. | |
476 | * | |
477 | * Either errreg or valreg may be $31, in which case nothing happens. | |
478 | * | |
479 | * The exception fixup information "just so happens" to be arranged | |
480 | * as in a MEM format instruction. This lets us emit our three | |
481 | * values like so: | |
482 | * | |
483 | * lda valreg, nextinsn(errreg) | |
484 | * | |
485 | */ | |
486 | ||
487 | struct exception_table_entry | |
488 | { | |
489 | signed int insn; | |
490 | union exception_fixup { | |
491 | unsigned unit; | |
492 | struct { | |
493 | signed int nextinsn : 16; | |
494 | unsigned int errreg : 5; | |
495 | unsigned int valreg : 5; | |
496 | } bits; | |
497 | } fixup; | |
498 | }; | |
499 | ||
500 | /* Returns the new pc */ | |
501 | #define fixup_exception(map_reg, fixup, pc) \ | |
502 | ({ \ | |
503 | if ((fixup)->fixup.bits.valreg != 31) \ | |
504 | map_reg((fixup)->fixup.bits.valreg) = 0; \ | |
505 | if ((fixup)->fixup.bits.errreg != 31) \ | |
506 | map_reg((fixup)->fixup.bits.errreg) = -EFAULT; \ | |
507 | (pc) + (fixup)->fixup.bits.nextinsn; \ | |
508 | }) | |
509 | ||
510 | ||
511 | #endif /* __ALPHA_UACCESS_H */ |