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2df5e8bc SR |
1 | #ifndef _ARCH_POWERPC_UACCESS_H |
2 | #define _ARCH_POWERPC_UACCESS_H | |
3 | ||
4 | #ifdef __KERNEL__ | |
5 | #ifndef __ASSEMBLY__ | |
6 | ||
7 | #include <linux/sched.h> | |
8 | #include <linux/errno.h> | |
9 | #include <asm/processor.h> | |
10 | ||
11 | #define VERIFY_READ 0 | |
12 | #define VERIFY_WRITE 1 | |
13 | ||
14 | /* | |
15 | * The fs value determines whether argument validity checking should be | |
16 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
17 | * get_fs() == KERNEL_DS, checking is bypassed. | |
18 | * | |
19 | * For historical reasons, these macros are grossly misnamed. | |
20 | * | |
21 | * The fs/ds values are now the highest legal address in the "segment". | |
22 | * This simplifies the checking in the routines below. | |
23 | */ | |
24 | ||
25 | #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) | |
26 | ||
5015b494 | 27 | #define KERNEL_DS MAKE_MM_SEG(~0UL) |
2df5e8bc | 28 | #ifdef __powerpc64__ |
5015b494 SR |
29 | /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ |
30 | #define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1) | |
2df5e8bc | 31 | #else |
2df5e8bc SR |
32 | #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) |
33 | #endif | |
34 | ||
35 | #define get_ds() (KERNEL_DS) | |
36 | #define get_fs() (current->thread.fs) | |
37 | #define set_fs(val) (current->thread.fs = (val)) | |
38 | ||
39 | #define segment_eq(a, b) ((a).seg == (b).seg) | |
40 | ||
41 | #ifdef __powerpc64__ | |
42 | /* | |
5015b494 SR |
43 | * This check is sufficient because there is a large enough |
44 | * gap between user addresses and the kernel addresses | |
2df5e8bc SR |
45 | */ |
46 | #define __access_ok(addr, size, segment) \ | |
5015b494 | 47 | (((addr) <= (segment).seg) && ((size) <= (segment).seg)) |
2df5e8bc SR |
48 | |
49 | #else | |
50 | ||
51 | #define __access_ok(addr, size, segment) \ | |
52 | (((addr) <= (segment).seg) && \ | |
53 | (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) | |
54 | ||
55 | #endif | |
56 | ||
57 | #define access_ok(type, addr, size) \ | |
58 | (__chk_user_ptr(addr), \ | |
59 | __access_ok((__force unsigned long)(addr), (size), get_fs())) | |
60 | ||
61 | /* | |
62 | * The exception table consists of pairs of addresses: the first is the | |
63 | * address of an instruction that is allowed to fault, and the second is | |
64 | * the address at which the program should continue. No registers are | |
65 | * modified, so it is entirely up to the continuation code to figure out | |
66 | * what to do. | |
67 | * | |
68 | * All the routines below use bits of fixup code that are out of line | |
69 | * with the main instruction path. This means when everything is well, | |
70 | * we don't even have to jump over them. Further, they do not intrude | |
71 | * on our cache or tlb entries. | |
72 | */ | |
73 | ||
74 | struct exception_table_entry { | |
75 | unsigned long insn; | |
76 | unsigned long fixup; | |
77 | }; | |
78 | ||
79 | /* | |
80 | * These are the main single-value transfer routines. They automatically | |
81 | * use the right size if we just have the right pointer type. | |
82 | * | |
83 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
84 | * and yet we don't want to do any pointers, because that is too much | |
85 | * of a performance impact. Thus we have a few rather ugly macros here, | |
86 | * and hide all the ugliness from the user. | |
87 | * | |
88 | * The "__xxx" versions of the user access functions are versions that | |
89 | * do not verify the address space, that must have been done previously | |
90 | * with a separate "access_ok()" call (this is used when we do multiple | |
91 | * accesses to the same area of user memory). | |
92 | * | |
93 | * As we use the same address space for kernel and user data on the | |
94 | * PowerPC, we can just do these as direct assignments. (Of course, the | |
95 | * exception handling means that it's no longer "just"...) | |
96 | * | |
97 | * The "user64" versions of the user access functions are versions that | |
98 | * allow access of 64-bit data. The "get_user" functions do not | |
99 | * properly handle 64-bit data because the value gets down cast to a long. | |
100 | * The "put_user" functions already handle 64-bit data properly but we add | |
101 | * "user64" versions for completeness | |
102 | */ | |
103 | #define get_user(x, ptr) \ | |
104 | __get_user_check((x), (ptr), sizeof(*(ptr))) | |
105 | #define put_user(x, ptr) \ | |
106 | __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
107 | ||
108 | #define __get_user(x, ptr) \ | |
109 | __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
110 | #define __put_user(x, ptr) \ | |
111 | __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
112 | #ifndef __powerpc64__ | |
113 | #define __get_user64(x, ptr) \ | |
114 | __get_user64_nocheck((x), (ptr), sizeof(*(ptr))) | |
115 | #define __put_user64(x, ptr) __put_user(x, ptr) | |
116 | #endif | |
117 | ||
2df5e8bc SR |
118 | #define __get_user_unaligned __get_user |
119 | #define __put_user_unaligned __put_user | |
2df5e8bc SR |
120 | |
121 | extern long __put_user_bad(void); | |
122 | ||
123 | #ifdef __powerpc64__ | |
124 | #define __EX_TABLE_ALIGN "3" | |
125 | #define __EX_TABLE_TYPE "llong" | |
126 | #else | |
127 | #define __EX_TABLE_ALIGN "2" | |
128 | #define __EX_TABLE_TYPE "long" | |
129 | #endif | |
130 | ||
131 | /* | |
132 | * We don't tell gcc that we are accessing memory, but this is OK | |
133 | * because we do not write to any memory gcc knows about, so there | |
134 | * are no aliasing issues. | |
135 | */ | |
136 | #define __put_user_asm(x, addr, err, op) \ | |
137 | __asm__ __volatile__( \ | |
138 | "1: " op " %1,0(%2) # put_user\n" \ | |
139 | "2:\n" \ | |
140 | ".section .fixup,\"ax\"\n" \ | |
141 | "3: li %0,%3\n" \ | |
142 | " b 2b\n" \ | |
143 | ".previous\n" \ | |
144 | ".section __ex_table,\"a\"\n" \ | |
145 | " .align " __EX_TABLE_ALIGN "\n" \ | |
146 | " ."__EX_TABLE_TYPE" 1b,3b\n" \ | |
147 | ".previous" \ | |
148 | : "=r" (err) \ | |
149 | : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) | |
150 | ||
5015b494 SR |
151 | #ifdef __powerpc64__ |
152 | #define __put_user_asm2(x, ptr, retval) \ | |
153 | __put_user_asm(x, ptr, retval, "std") | |
154 | #else /* __powerpc64__ */ | |
2df5e8bc SR |
155 | #define __put_user_asm2(x, addr, err) \ |
156 | __asm__ __volatile__( \ | |
157 | "1: stw %1,0(%2)\n" \ | |
158 | "2: stw %1+1,4(%2)\n" \ | |
159 | "3:\n" \ | |
160 | ".section .fixup,\"ax\"\n" \ | |
161 | "4: li %0,%3\n" \ | |
162 | " b 3b\n" \ | |
163 | ".previous\n" \ | |
164 | ".section __ex_table,\"a\"\n" \ | |
165 | " .align " __EX_TABLE_ALIGN "\n" \ | |
166 | " ." __EX_TABLE_TYPE " 1b,4b\n" \ | |
167 | " ." __EX_TABLE_TYPE " 2b,4b\n" \ | |
168 | ".previous" \ | |
169 | : "=r" (err) \ | |
170 | : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) | |
2df5e8bc SR |
171 | #endif /* __powerpc64__ */ |
172 | ||
173 | #define __put_user_size(x, ptr, size, retval) \ | |
174 | do { \ | |
175 | retval = 0; \ | |
176 | switch (size) { \ | |
177 | case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ | |
178 | case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ | |
179 | case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ | |
180 | case 8: __put_user_asm2(x, ptr, retval); break; \ | |
181 | default: __put_user_bad(); \ | |
182 | } \ | |
183 | } while (0) | |
184 | ||
185 | #define __put_user_nocheck(x, ptr, size) \ | |
186 | ({ \ | |
187 | long __pu_err; \ | |
188 | might_sleep(); \ | |
189 | __chk_user_ptr(ptr); \ | |
190 | __put_user_size((x), (ptr), (size), __pu_err); \ | |
191 | __pu_err; \ | |
192 | }) | |
193 | ||
194 | #define __put_user_check(x, ptr, size) \ | |
195 | ({ \ | |
196 | long __pu_err = -EFAULT; \ | |
197 | __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ | |
198 | might_sleep(); \ | |
199 | if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ | |
200 | __put_user_size((x), __pu_addr, (size), __pu_err); \ | |
201 | __pu_err; \ | |
202 | }) | |
203 | ||
204 | extern long __get_user_bad(void); | |
205 | ||
206 | #define __get_user_asm(x, addr, err, op) \ | |
207 | __asm__ __volatile__( \ | |
5015b494 | 208 | "1: "op" %1,0(%2) # get_user\n" \ |
2df5e8bc SR |
209 | "2:\n" \ |
210 | ".section .fixup,\"ax\"\n" \ | |
211 | "3: li %0,%3\n" \ | |
212 | " li %1,0\n" \ | |
213 | " b 2b\n" \ | |
214 | ".previous\n" \ | |
215 | ".section __ex_table,\"a\"\n" \ | |
216 | " .align "__EX_TABLE_ALIGN "\n" \ | |
217 | " ." __EX_TABLE_TYPE " 1b,3b\n" \ | |
218 | ".previous" \ | |
219 | : "=r" (err), "=r" (x) \ | |
220 | : "b" (addr), "i" (-EFAULT), "0" (err)) | |
221 | ||
5015b494 SR |
222 | #ifdef __powerpc64__ |
223 | #define __get_user_asm2(x, addr, err) \ | |
224 | __get_user_asm(x, addr, err, "ld") | |
225 | #else /* __powerpc64__ */ | |
226 | #define __get_user_asm2(x, addr, err) \ | |
2df5e8bc SR |
227 | __asm__ __volatile__( \ |
228 | "1: lwz %1,0(%2)\n" \ | |
229 | "2: lwz %1+1,4(%2)\n" \ | |
230 | "3:\n" \ | |
231 | ".section .fixup,\"ax\"\n" \ | |
232 | "4: li %0,%3\n" \ | |
233 | " li %1,0\n" \ | |
234 | " li %1+1,0\n" \ | |
235 | " b 3b\n" \ | |
236 | ".previous\n" \ | |
237 | ".section __ex_table,\"a\"\n" \ | |
238 | " .align " __EX_TABLE_ALIGN "\n" \ | |
239 | " ." __EX_TABLE_TYPE " 1b,4b\n" \ | |
240 | " ." __EX_TABLE_TYPE " 2b,4b\n" \ | |
241 | ".previous" \ | |
242 | : "=r" (err), "=&r" (x) \ | |
243 | : "b" (addr), "i" (-EFAULT), "0" (err)) | |
2df5e8bc SR |
244 | #endif /* __powerpc64__ */ |
245 | ||
246 | #define __get_user_size(x, ptr, size, retval) \ | |
247 | do { \ | |
248 | retval = 0; \ | |
249 | __chk_user_ptr(ptr); \ | |
5015b494 SR |
250 | if (size > sizeof(x)) \ |
251 | (x) = __get_user_bad(); \ | |
2df5e8bc SR |
252 | switch (size) { \ |
253 | case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ | |
254 | case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ | |
255 | case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ | |
256 | case 8: __get_user_asm2(x, ptr, retval); break; \ | |
257 | default: (x) = __get_user_bad(); \ | |
258 | } \ | |
259 | } while (0) | |
260 | ||
261 | #define __get_user_nocheck(x, ptr, size) \ | |
262 | ({ \ | |
263 | long __gu_err; \ | |
264 | unsigned long __gu_val; \ | |
265 | __chk_user_ptr(ptr); \ | |
266 | might_sleep(); \ | |
267 | __get_user_size(__gu_val, (ptr), (size), __gu_err); \ | |
268 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
269 | __gu_err; \ | |
270 | }) | |
271 | ||
272 | #ifndef __powerpc64__ | |
273 | #define __get_user64_nocheck(x, ptr, size) \ | |
274 | ({ \ | |
275 | long __gu_err; \ | |
276 | long long __gu_val; \ | |
277 | __chk_user_ptr(ptr); \ | |
278 | might_sleep(); \ | |
279 | __get_user_size(__gu_val, (ptr), (size), __gu_err); \ | |
280 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
281 | __gu_err; \ | |
282 | }) | |
283 | #endif /* __powerpc64__ */ | |
284 | ||
285 | #define __get_user_check(x, ptr, size) \ | |
286 | ({ \ | |
287 | long __gu_err = -EFAULT; \ | |
288 | unsigned long __gu_val = 0; \ | |
289 | const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ | |
5015b494 | 290 | might_sleep(); \ |
2df5e8bc SR |
291 | if (access_ok(VERIFY_READ, __gu_addr, (size))) \ |
292 | __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ | |
293 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
294 | __gu_err; \ | |
295 | }) | |
296 | ||
297 | /* more complex routines */ | |
298 | ||
299 | extern unsigned long __copy_tofrom_user(void __user *to, | |
300 | const void __user *from, unsigned long size); | |
301 | ||
302 | #ifndef __powerpc64__ | |
5015b494 SR |
303 | |
304 | extern inline unsigned long copy_from_user(void *to, | |
305 | const void __user *from, unsigned long n) | |
2df5e8bc SR |
306 | { |
307 | unsigned long over; | |
308 | ||
309 | if (access_ok(VERIFY_READ, from, n)) | |
310 | return __copy_tofrom_user((__force void __user *)to, from, n); | |
311 | if ((unsigned long)from < TASK_SIZE) { | |
312 | over = (unsigned long)from + n - TASK_SIZE; | |
313 | return __copy_tofrom_user((__force void __user *)to, from, | |
314 | n - over) + over; | |
315 | } | |
316 | return n; | |
317 | } | |
318 | ||
5015b494 SR |
319 | extern inline unsigned long copy_to_user(void __user *to, |
320 | const void *from, unsigned long n) | |
2df5e8bc SR |
321 | { |
322 | unsigned long over; | |
323 | ||
324 | if (access_ok(VERIFY_WRITE, to, n)) | |
325 | return __copy_tofrom_user(to, (__force void __user *)from, n); | |
326 | if ((unsigned long)to < TASK_SIZE) { | |
327 | over = (unsigned long)to + n - TASK_SIZE; | |
328 | return __copy_tofrom_user(to, (__force void __user *)from, | |
329 | n - over) + over; | |
330 | } | |
331 | return n; | |
332 | } | |
333 | ||
334 | #else /* __powerpc64__ */ | |
335 | ||
5015b494 SR |
336 | #define __copy_in_user(to, from, size) \ |
337 | __copy_tofrom_user((to), (from), (size)) | |
338 | ||
339 | extern unsigned long copy_from_user(void *to, const void __user *from, | |
340 | unsigned long n); | |
341 | extern unsigned long copy_to_user(void __user *to, const void *from, | |
342 | unsigned long n); | |
343 | extern unsigned long copy_in_user(void __user *to, const void __user *from, | |
344 | unsigned long n); | |
345 | ||
48fe4871 SR |
346 | #endif /* __powerpc64__ */ |
347 | ||
5015b494 SR |
348 | static inline unsigned long __copy_from_user_inatomic(void *to, |
349 | const void __user *from, unsigned long n) | |
2df5e8bc SR |
350 | { |
351 | if (__builtin_constant_p(n) && (n <= 8)) { | |
352 | unsigned long ret; | |
353 | ||
354 | switch (n) { | |
355 | case 1: | |
356 | __get_user_size(*(u8 *)to, from, 1, ret); | |
357 | break; | |
358 | case 2: | |
359 | __get_user_size(*(u16 *)to, from, 2, ret); | |
360 | break; | |
361 | case 4: | |
362 | __get_user_size(*(u32 *)to, from, 4, ret); | |
363 | break; | |
364 | case 8: | |
365 | __get_user_size(*(u64 *)to, from, 8, ret); | |
366 | break; | |
367 | } | |
48fe4871 SR |
368 | if (ret == 0) |
369 | return 0; | |
2df5e8bc | 370 | } |
48fe4871 | 371 | return __copy_tofrom_user((__force void __user *)to, from, n); |
2df5e8bc SR |
372 | } |
373 | ||
5015b494 SR |
374 | static inline unsigned long __copy_to_user_inatomic(void __user *to, |
375 | const void *from, unsigned long n) | |
2df5e8bc SR |
376 | { |
377 | if (__builtin_constant_p(n) && (n <= 8)) { | |
378 | unsigned long ret; | |
379 | ||
380 | switch (n) { | |
381 | case 1: | |
382 | __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); | |
383 | break; | |
384 | case 2: | |
385 | __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); | |
386 | break; | |
387 | case 4: | |
388 | __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); | |
389 | break; | |
390 | case 8: | |
391 | __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); | |
392 | break; | |
393 | } | |
48fe4871 SR |
394 | if (ret == 0) |
395 | return 0; | |
2df5e8bc | 396 | } |
48fe4871 | 397 | return __copy_tofrom_user(to, (__force const void __user *)from, n); |
2df5e8bc SR |
398 | } |
399 | ||
5015b494 SR |
400 | static inline unsigned long __copy_from_user(void *to, |
401 | const void __user *from, unsigned long size) | |
2df5e8bc SR |
402 | { |
403 | might_sleep(); | |
2df5e8bc | 404 | return __copy_from_user_inatomic(to, from, size); |
2df5e8bc SR |
405 | } |
406 | ||
5015b494 SR |
407 | static inline unsigned long __copy_to_user(void __user *to, |
408 | const void *from, unsigned long size) | |
2df5e8bc SR |
409 | { |
410 | might_sleep(); | |
2df5e8bc | 411 | return __copy_to_user_inatomic(to, from, size); |
2df5e8bc SR |
412 | } |
413 | ||
2df5e8bc SR |
414 | extern unsigned long __clear_user(void __user *addr, unsigned long size); |
415 | ||
416 | static inline unsigned long clear_user(void __user *addr, unsigned long size) | |
417 | { | |
418 | might_sleep(); | |
419 | if (likely(access_ok(VERIFY_WRITE, addr, size))) | |
420 | return __clear_user(addr, size); | |
2df5e8bc SR |
421 | if ((unsigned long)addr < TASK_SIZE) { |
422 | unsigned long over = (unsigned long)addr + size - TASK_SIZE; | |
423 | return __clear_user(addr, size - over) + over; | |
424 | } | |
2df5e8bc SR |
425 | return size; |
426 | } | |
427 | ||
428 | extern int __strncpy_from_user(char *dst, const char __user *src, long count); | |
429 | ||
430 | static inline long strncpy_from_user(char *dst, const char __user *src, | |
431 | long count) | |
432 | { | |
433 | might_sleep(); | |
434 | if (likely(access_ok(VERIFY_READ, src, 1))) | |
435 | return __strncpy_from_user(dst, src, count); | |
436 | return -EFAULT; | |
437 | } | |
438 | ||
439 | /* | |
440 | * Return the size of a string (including the ending 0) | |
441 | * | |
442 | * Return 0 for error | |
443 | */ | |
2df5e8bc | 444 | extern int __strnlen_user(const char __user *str, long len, unsigned long top); |
2df5e8bc SR |
445 | |
446 | /* | |
447 | * Returns the length of the string at str (including the null byte), | |
448 | * or 0 if we hit a page we can't access, | |
449 | * or something > len if we didn't find a null byte. | |
450 | * | |
451 | * The `top' parameter to __strnlen_user is to make sure that | |
452 | * we can never overflow from the user area into kernel space. | |
453 | */ | |
454 | static inline int strnlen_user(const char __user *str, long len) | |
455 | { | |
2df5e8bc SR |
456 | unsigned long top = current->thread.fs.seg; |
457 | ||
458 | if ((unsigned long)str > top) | |
459 | return 0; | |
460 | return __strnlen_user(str, len, top); | |
2df5e8bc SR |
461 | } |
462 | ||
463 | #define strlen_user(str) strnlen_user((str), 0x7ffffffe) | |
464 | ||
465 | #endif /* __ASSEMBLY__ */ | |
466 | #endif /* __KERNEL__ */ | |
467 | ||
468 | #endif /* _ARCH_POWERPC_UACCESS_H */ |