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1 | /* |
2 | * include/asm-s390/uaccess.h | |
3 | * | |
4 | * S390 version | |
5 | * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation | |
6 | * Author(s): Hartmut Penner (hp@de.ibm.com), | |
7 | * Martin Schwidefsky (schwidefsky@de.ibm.com) | |
8 | * | |
9 | * Derived from "include/asm-i386/uaccess.h" | |
10 | */ | |
11 | #ifndef __S390_UACCESS_H | |
12 | #define __S390_UACCESS_H | |
13 | ||
14 | /* | |
15 | * User space memory access functions | |
16 | */ | |
17 | #include <linux/sched.h> | |
18 | #include <linux/errno.h> | |
19 | ||
20 | #define VERIFY_READ 0 | |
21 | #define VERIFY_WRITE 1 | |
22 | ||
23 | ||
24 | /* | |
25 | * The fs value determines whether argument validity checking should be | |
26 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
27 | * get_fs() == KERNEL_DS, checking is bypassed. | |
28 | * | |
29 | * For historical reasons, these macros are grossly misnamed. | |
30 | */ | |
31 | ||
32 | #define MAKE_MM_SEG(a) ((mm_segment_t) { (a) }) | |
33 | ||
34 | ||
35 | #define KERNEL_DS MAKE_MM_SEG(0) | |
36 | #define USER_DS MAKE_MM_SEG(1) | |
37 | ||
38 | #define get_ds() (KERNEL_DS) | |
39 | #define get_fs() (current->thread.mm_segment) | |
40 | ||
41 | #ifdef __s390x__ | |
42 | #define set_fs(x) \ | |
43 | ({ \ | |
44 | unsigned long __pto; \ | |
45 | current->thread.mm_segment = (x); \ | |
46 | __pto = current->thread.mm_segment.ar4 ? \ | |
47 | S390_lowcore.user_asce : S390_lowcore.kernel_asce; \ | |
48 | asm volatile ("lctlg 7,7,%0" : : "m" (__pto) ); \ | |
49 | }) | |
50 | #else | |
51 | #define set_fs(x) \ | |
52 | ({ \ | |
53 | unsigned long __pto; \ | |
54 | current->thread.mm_segment = (x); \ | |
55 | __pto = current->thread.mm_segment.ar4 ? \ | |
56 | S390_lowcore.user_asce : S390_lowcore.kernel_asce; \ | |
57 | asm volatile ("lctl 7,7,%0" : : "m" (__pto) ); \ | |
58 | }) | |
59 | #endif | |
60 | ||
61 | #define segment_eq(a,b) ((a).ar4 == (b).ar4) | |
62 | ||
63 | ||
64 | #define __access_ok(addr,size) (1) | |
65 | ||
66 | #define access_ok(type,addr,size) __access_ok(addr,size) | |
67 | ||
68 | /* this function will go away soon - use access_ok() instead */ | |
69 | extern inline int __deprecated verify_area(int type, const void __user *addr, | |
70 | unsigned long size) | |
71 | { | |
72 | return access_ok(type, addr, size) ? 0 : -EFAULT; | |
73 | } | |
74 | ||
75 | /* | |
76 | * The exception table consists of pairs of addresses: the first is the | |
77 | * address of an instruction that is allowed to fault, and the second is | |
78 | * the address at which the program should continue. No registers are | |
79 | * modified, so it is entirely up to the continuation code to figure out | |
80 | * what to do. | |
81 | * | |
82 | * All the routines below use bits of fixup code that are out of line | |
83 | * with the main instruction path. This means when everything is well, | |
84 | * we don't even have to jump over them. Further, they do not intrude | |
85 | * on our cache or tlb entries. | |
86 | */ | |
87 | ||
88 | struct exception_table_entry | |
89 | { | |
90 | unsigned long insn, fixup; | |
91 | }; | |
92 | ||
93 | #ifndef __s390x__ | |
94 | #define __uaccess_fixup \ | |
95 | ".section .fixup,\"ax\"\n" \ | |
96 | "2: lhi %0,%4\n" \ | |
97 | " bras 1,3f\n" \ | |
98 | " .long 1b\n" \ | |
99 | "3: l 1,0(1)\n" \ | |
100 | " br 1\n" \ | |
101 | ".previous\n" \ | |
102 | ".section __ex_table,\"a\"\n" \ | |
103 | " .align 4\n" \ | |
104 | " .long 0b,2b\n" \ | |
105 | ".previous" | |
106 | #define __uaccess_clobber "cc", "1" | |
107 | #else /* __s390x__ */ | |
108 | #define __uaccess_fixup \ | |
109 | ".section .fixup,\"ax\"\n" \ | |
110 | "2: lghi %0,%4\n" \ | |
111 | " jg 1b\n" \ | |
112 | ".previous\n" \ | |
113 | ".section __ex_table,\"a\"\n" \ | |
114 | " .align 8\n" \ | |
115 | " .quad 0b,2b\n" \ | |
116 | ".previous" | |
117 | #define __uaccess_clobber "cc" | |
118 | #endif /* __s390x__ */ | |
119 | ||
120 | /* | |
121 | * These are the main single-value transfer routines. They automatically | |
122 | * use the right size if we just have the right pointer type. | |
123 | */ | |
124 | #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) | |
125 | #define __put_user_asm(x, ptr, err) \ | |
126 | ({ \ | |
127 | err = 0; \ | |
128 | asm volatile( \ | |
129 | "0: mvcs 0(%1,%2),%3,%0\n" \ | |
130 | "1:\n" \ | |
131 | __uaccess_fixup \ | |
132 | : "+&d" (err) \ | |
133 | : "d" (sizeof(*(ptr))), "a" (ptr), "Q" (x), \ | |
134 | "K" (-EFAULT) \ | |
135 | : __uaccess_clobber ); \ | |
136 | }) | |
137 | #else | |
138 | #define __put_user_asm(x, ptr, err) \ | |
139 | ({ \ | |
140 | err = 0; \ | |
141 | asm volatile( \ | |
142 | "0: mvcs 0(%1,%2),0(%3),%0\n" \ | |
143 | "1:\n" \ | |
144 | __uaccess_fixup \ | |
145 | : "+&d" (err) \ | |
146 | : "d" (sizeof(*(ptr))), "a" (ptr), "a" (&(x)), \ | |
147 | "K" (-EFAULT), "m" (x) \ | |
148 | : __uaccess_clobber ); \ | |
149 | }) | |
150 | #endif | |
151 | ||
152 | #ifndef __CHECKER__ | |
153 | #define __put_user(x, ptr) \ | |
154 | ({ \ | |
155 | __typeof__(*(ptr)) __x = (x); \ | |
156 | int __pu_err; \ | |
157 | switch (sizeof (*(ptr))) { \ | |
158 | case 1: \ | |
159 | case 2: \ | |
160 | case 4: \ | |
161 | case 8: \ | |
162 | __put_user_asm(__x, ptr, __pu_err); \ | |
163 | break; \ | |
164 | default: \ | |
165 | __put_user_bad(); \ | |
166 | break; \ | |
167 | } \ | |
168 | __pu_err; \ | |
169 | }) | |
170 | #else | |
171 | #define __put_user(x, ptr) \ | |
172 | ({ \ | |
173 | void __user *p; \ | |
174 | p = (ptr); \ | |
175 | 0; \ | |
176 | }) | |
177 | #endif | |
178 | ||
179 | #define put_user(x, ptr) \ | |
180 | ({ \ | |
181 | might_sleep(); \ | |
182 | __put_user(x, ptr); \ | |
183 | }) | |
184 | ||
185 | ||
186 | extern int __put_user_bad(void) __attribute__((noreturn)); | |
187 | ||
188 | #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) | |
189 | #define __get_user_asm(x, ptr, err) \ | |
190 | ({ \ | |
191 | err = 0; \ | |
192 | asm volatile ( \ | |
193 | "0: mvcp %O1(%2,%R1),0(%3),%0\n" \ | |
194 | "1:\n" \ | |
195 | __uaccess_fixup \ | |
196 | : "+&d" (err), "=Q" (x) \ | |
197 | : "d" (sizeof(*(ptr))), "a" (ptr), \ | |
198 | "K" (-EFAULT) \ | |
199 | : __uaccess_clobber ); \ | |
200 | }) | |
201 | #else | |
202 | #define __get_user_asm(x, ptr, err) \ | |
203 | ({ \ | |
204 | err = 0; \ | |
205 | asm volatile ( \ | |
206 | "0: mvcp 0(%2,%5),0(%3),%0\n" \ | |
207 | "1:\n" \ | |
208 | __uaccess_fixup \ | |
209 | : "+&d" (err), "=m" (x) \ | |
210 | : "d" (sizeof(*(ptr))), "a" (ptr), \ | |
211 | "K" (-EFAULT), "a" (&(x)) \ | |
212 | : __uaccess_clobber ); \ | |
213 | }) | |
214 | #endif | |
215 | ||
216 | #ifndef __CHECKER__ | |
217 | #define __get_user(x, ptr) \ | |
218 | ({ \ | |
219 | __typeof__(*(ptr)) __x; \ | |
220 | int __gu_err; \ | |
221 | switch (sizeof(*(ptr))) { \ | |
222 | case 1: \ | |
223 | case 2: \ | |
224 | case 4: \ | |
225 | case 8: \ | |
226 | __get_user_asm(__x, ptr, __gu_err); \ | |
227 | break; \ | |
228 | default: \ | |
229 | __get_user_bad(); \ | |
230 | break; \ | |
231 | } \ | |
232 | (x) = __x; \ | |
233 | __gu_err; \ | |
234 | }) | |
235 | #else | |
236 | #define __get_user(x, ptr) \ | |
237 | ({ \ | |
238 | void __user *p; \ | |
239 | p = (ptr); \ | |
240 | 0; \ | |
241 | }) | |
242 | #endif | |
243 | ||
244 | ||
245 | #define get_user(x, ptr) \ | |
246 | ({ \ | |
247 | might_sleep(); \ | |
248 | __get_user(x, ptr); \ | |
249 | }) | |
250 | ||
251 | extern int __get_user_bad(void) __attribute__((noreturn)); | |
252 | ||
253 | #define __put_user_unaligned __put_user | |
254 | #define __get_user_unaligned __get_user | |
255 | ||
256 | extern long __copy_to_user_asm(const void *from, long n, void __user *to); | |
257 | ||
258 | /** | |
259 | * __copy_to_user: - Copy a block of data into user space, with less checking. | |
260 | * @to: Destination address, in user space. | |
261 | * @from: Source address, in kernel space. | |
262 | * @n: Number of bytes to copy. | |
263 | * | |
264 | * Context: User context only. This function may sleep. | |
265 | * | |
266 | * Copy data from kernel space to user space. Caller must check | |
267 | * the specified block with access_ok() before calling this function. | |
268 | * | |
269 | * Returns number of bytes that could not be copied. | |
270 | * On success, this will be zero. | |
271 | */ | |
272 | static inline unsigned long | |
273 | __copy_to_user(void __user *to, const void *from, unsigned long n) | |
274 | { | |
275 | return __copy_to_user_asm(from, n, to); | |
276 | } | |
277 | ||
278 | #define __copy_to_user_inatomic __copy_to_user | |
279 | #define __copy_from_user_inatomic __copy_from_user | |
280 | ||
281 | /** | |
282 | * copy_to_user: - Copy a block of data into user space. | |
283 | * @to: Destination address, in user space. | |
284 | * @from: Source address, in kernel space. | |
285 | * @n: Number of bytes to copy. | |
286 | * | |
287 | * Context: User context only. This function may sleep. | |
288 | * | |
289 | * Copy data from kernel space to user space. | |
290 | * | |
291 | * Returns number of bytes that could not be copied. | |
292 | * On success, this will be zero. | |
293 | */ | |
294 | static inline unsigned long | |
295 | copy_to_user(void __user *to, const void *from, unsigned long n) | |
296 | { | |
297 | might_sleep(); | |
298 | if (access_ok(VERIFY_WRITE, to, n)) | |
299 | n = __copy_to_user(to, from, n); | |
300 | return n; | |
301 | } | |
302 | ||
303 | extern long __copy_from_user_asm(void *to, long n, const void __user *from); | |
304 | ||
305 | /** | |
306 | * __copy_from_user: - Copy a block of data from user space, with less checking. | |
307 | * @to: Destination address, in kernel space. | |
308 | * @from: Source address, in user space. | |
309 | * @n: Number of bytes to copy. | |
310 | * | |
311 | * Context: User context only. This function may sleep. | |
312 | * | |
313 | * Copy data from user space to kernel space. Caller must check | |
314 | * the specified block with access_ok() before calling this function. | |
315 | * | |
316 | * Returns number of bytes that could not be copied. | |
317 | * On success, this will be zero. | |
318 | * | |
319 | * If some data could not be copied, this function will pad the copied | |
320 | * data to the requested size using zero bytes. | |
321 | */ | |
322 | static inline unsigned long | |
323 | __copy_from_user(void *to, const void __user *from, unsigned long n) | |
324 | { | |
325 | return __copy_from_user_asm(to, n, from); | |
326 | } | |
327 | ||
328 | /** | |
329 | * copy_from_user: - Copy a block of data from user space. | |
330 | * @to: Destination address, in kernel space. | |
331 | * @from: Source address, in user space. | |
332 | * @n: Number of bytes to copy. | |
333 | * | |
334 | * Context: User context only. This function may sleep. | |
335 | * | |
336 | * Copy data from user space to kernel space. | |
337 | * | |
338 | * Returns number of bytes that could not be copied. | |
339 | * On success, this will be zero. | |
340 | * | |
341 | * If some data could not be copied, this function will pad the copied | |
342 | * data to the requested size using zero bytes. | |
343 | */ | |
344 | static inline unsigned long | |
345 | copy_from_user(void *to, const void __user *from, unsigned long n) | |
346 | { | |
347 | might_sleep(); | |
348 | if (access_ok(VERIFY_READ, from, n)) | |
349 | n = __copy_from_user(to, from, n); | |
350 | else | |
351 | memset(to, 0, n); | |
352 | return n; | |
353 | } | |
354 | ||
355 | extern unsigned long __copy_in_user_asm(const void __user *from, long n, | |
356 | void __user *to); | |
357 | ||
358 | static inline unsigned long | |
359 | __copy_in_user(void __user *to, const void __user *from, unsigned long n) | |
360 | { | |
361 | return __copy_in_user_asm(from, n, to); | |
362 | } | |
363 | ||
364 | static inline unsigned long | |
365 | copy_in_user(void __user *to, const void __user *from, unsigned long n) | |
366 | { | |
367 | might_sleep(); | |
368 | if (__access_ok(from,n) && __access_ok(to,n)) | |
369 | n = __copy_in_user_asm(from, n, to); | |
370 | return n; | |
371 | } | |
372 | ||
373 | /* | |
374 | * Copy a null terminated string from userspace. | |
375 | */ | |
376 | extern long __strncpy_from_user_asm(long count, char *dst, | |
377 | const char __user *src); | |
378 | ||
379 | static inline long | |
380 | strncpy_from_user(char *dst, const char __user *src, long count) | |
381 | { | |
382 | long res = -EFAULT; | |
383 | might_sleep(); | |
384 | if (access_ok(VERIFY_READ, src, 1)) | |
385 | res = __strncpy_from_user_asm(count, dst, src); | |
386 | return res; | |
387 | } | |
388 | ||
389 | ||
390 | extern long __strnlen_user_asm(long count, const char __user *src); | |
391 | ||
392 | static inline unsigned long | |
393 | strnlen_user(const char __user * src, unsigned long n) | |
394 | { | |
395 | might_sleep(); | |
396 | return __strnlen_user_asm(n, src); | |
397 | } | |
398 | ||
399 | /** | |
400 | * strlen_user: - Get the size of a string in user space. | |
401 | * @str: The string to measure. | |
402 | * | |
403 | * Context: User context only. This function may sleep. | |
404 | * | |
405 | * Get the size of a NUL-terminated string in user space. | |
406 | * | |
407 | * Returns the size of the string INCLUDING the terminating NUL. | |
408 | * On exception, returns 0. | |
409 | * | |
410 | * If there is a limit on the length of a valid string, you may wish to | |
411 | * consider using strnlen_user() instead. | |
412 | */ | |
413 | #define strlen_user(str) strnlen_user(str, ~0UL) | |
414 | ||
415 | /* | |
416 | * Zero Userspace | |
417 | */ | |
418 | ||
419 | extern long __clear_user_asm(void __user *to, long n); | |
420 | ||
421 | static inline unsigned long | |
422 | __clear_user(void __user *to, unsigned long n) | |
423 | { | |
424 | return __clear_user_asm(to, n); | |
425 | } | |
426 | ||
427 | static inline unsigned long | |
428 | clear_user(void __user *to, unsigned long n) | |
429 | { | |
430 | might_sleep(); | |
431 | if (access_ok(VERIFY_WRITE, to, n)) | |
432 | n = __clear_user_asm(to, n); | |
433 | return n; | |
434 | } | |
435 | ||
436 | #endif /* __S390_UACCESS_H */ |