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ffa818b4 CL |
1 | #ifndef __SCORE_UACCESS_H |
2 | #define __SCORE_UACCESS_H | |
3 | ||
4 | #include <linux/kernel.h> | |
5 | #include <linux/errno.h> | |
6 | #include <linux/thread_info.h> | |
7 | ||
8 | #define VERIFY_READ 0 | |
9 | #define VERIFY_WRITE 1 | |
10 | ||
11 | #define get_ds() (KERNEL_DS) | |
12 | #define get_fs() (current_thread_info()->addr_limit) | |
13 | #define segment_eq(a, b) ((a).seg == (b).seg) | |
14 | ||
6bc9a396 | 15 | /* |
ffa818b4 CL |
16 | * Is a address valid? This does a straighforward calculation rather |
17 | * than tests. | |
18 | * | |
19 | * Address valid if: | |
20 | * - "addr" doesn't have any high-bits set | |
21 | * - AND "size" doesn't have any high-bits set | |
22 | * - AND "addr+size" doesn't have any high-bits set | |
23 | * - OR we are in kernel mode. | |
6bc9a396 | 24 | * |
ffa818b4 CL |
25 | * __ua_size() is a trick to avoid runtime checking of positive constant |
26 | * sizes; for those we already know at compile time that the size is ok. | |
6bc9a396 | 27 | */ |
ffa818b4 CL |
28 | #define __ua_size(size) \ |
29 | ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size)) | |
30 | ||
31 | /* | |
32 | * access_ok: - Checks if a user space pointer is valid | |
33 | * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that | |
34 | * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe | |
35 | * to write to a block, it is always safe to read from it. | |
36 | * @addr: User space pointer to start of block to check | |
37 | * @size: Size of block to check | |
38 | * | |
b3c395ef DH |
39 | * Context: User context only. This function may sleep if pagefaults are |
40 | * enabled. | |
ffa818b4 CL |
41 | * |
42 | * Checks if a pointer to a block of memory in user space is valid. | |
43 | * | |
44 | * Returns true (nonzero) if the memory block may be valid, false (zero) | |
45 | * if it is definitely invalid. | |
46 | * | |
47 | * Note that, depending on architecture, this function probably just | |
48 | * checks that the pointer is in the user space range - after calling | |
49 | * this function, memory access functions may still return -EFAULT. | |
50 | */ | |
51 | ||
52 | #define __access_ok(addr, size) \ | |
53 | (((long)((get_fs().seg) & \ | |
54 | ((addr) | ((addr) + (size)) | \ | |
55 | __ua_size(size)))) == 0) | |
56 | ||
57 | #define access_ok(type, addr, size) \ | |
58 | likely(__access_ok((unsigned long)(addr), (size))) | |
59 | ||
60 | /* | |
61 | * put_user: - Write a simple value into user space. | |
62 | * @x: Value to copy to user space. | |
63 | * @ptr: Destination address, in user space. | |
64 | * | |
b3c395ef DH |
65 | * Context: User context only. This function may sleep if pagefaults are |
66 | * enabled. | |
ffa818b4 CL |
67 | * |
68 | * This macro copies a single simple value from kernel space to user | |
69 | * space. It supports simple types like char and int, but not larger | |
70 | * data types like structures or arrays. | |
71 | * | |
72 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
73 | * to the result of dereferencing @ptr. | |
74 | * | |
75 | * Returns zero on success, or -EFAULT on error. | |
76 | */ | |
77 | #define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr))) | |
78 | ||
79 | /* | |
80 | * get_user: - Get a simple variable from user space. | |
81 | * @x: Variable to store result. | |
82 | * @ptr: Source address, in user space. | |
83 | * | |
b3c395ef DH |
84 | * Context: User context only. This function may sleep if pagefaults are |
85 | * enabled. | |
ffa818b4 CL |
86 | * |
87 | * This macro copies a single simple variable from user space to kernel | |
88 | * space. It supports simple types like char and int, but not larger | |
89 | * data types like structures or arrays. | |
90 | * | |
91 | * @ptr must have pointer-to-simple-variable type, and the result of | |
92 | * dereferencing @ptr must be assignable to @x without a cast. | |
93 | * | |
94 | * Returns zero on success, or -EFAULT on error. | |
95 | * On error, the variable @x is set to zero. | |
96 | */ | |
97 | #define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr))) | |
98 | ||
99 | /* | |
100 | * __put_user: - Write a simple value into user space, with less checking. | |
101 | * @x: Value to copy to user space. | |
102 | * @ptr: Destination address, in user space. | |
103 | * | |
b3c395ef DH |
104 | * Context: User context only. This function may sleep if pagefaults are |
105 | * enabled. | |
ffa818b4 CL |
106 | * |
107 | * This macro copies a single simple value from kernel space to user | |
108 | * space. It supports simple types like char and int, but not larger | |
109 | * data types like structures or arrays. | |
110 | * | |
111 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
112 | * to the result of dereferencing @ptr. | |
113 | * | |
114 | * Caller must check the pointer with access_ok() before calling this | |
115 | * function. | |
116 | * | |
117 | * Returns zero on success, or -EFAULT on error. | |
118 | */ | |
119 | #define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
120 | ||
121 | /* | |
122 | * __get_user: - Get a simple variable from user space, with less checking. | |
123 | * @x: Variable to store result. | |
124 | * @ptr: Source address, in user space. | |
125 | * | |
b3c395ef DH |
126 | * Context: User context only. This function may sleep if pagefaults are |
127 | * enabled. | |
ffa818b4 CL |
128 | * |
129 | * This macro copies a single simple variable from user space to kernel | |
130 | * space. It supports simple types like char and int, but not larger | |
131 | * data types like structures or arrays. | |
132 | * | |
133 | * @ptr must have pointer-to-simple-variable type, and the result of | |
134 | * dereferencing @ptr must be assignable to @x without a cast. | |
135 | * | |
136 | * Caller must check the pointer with access_ok() before calling this | |
137 | * function. | |
138 | * | |
139 | * Returns zero on success, or -EFAULT on error. | |
140 | * On error, the variable @x is set to zero. | |
141 | */ | |
142 | #define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
143 | ||
144 | struct __large_struct { unsigned long buf[100]; }; | |
145 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
146 | ||
147 | /* | |
148 | * Yuck. We need two variants, one for 64bit operation and one | |
149 | * for 32 bit mode and old iron. | |
150 | */ | |
151 | extern void __get_user_unknown(void); | |
152 | ||
153 | #define __get_user_common(val, size, ptr) \ | |
154 | do { \ | |
155 | switch (size) { \ | |
156 | case 1: \ | |
157 | __get_user_asm(val, "lb", ptr); \ | |
158 | break; \ | |
159 | case 2: \ | |
160 | __get_user_asm(val, "lh", ptr); \ | |
161 | break; \ | |
162 | case 4: \ | |
163 | __get_user_asm(val, "lw", ptr); \ | |
164 | break; \ | |
165 | case 8: \ | |
c2f18fa4 | 166 | if (__copy_from_user((void *)&val, ptr, 8) == 0) \ |
ffa818b4 CL |
167 | __gu_err = 0; \ |
168 | else \ | |
169 | __gu_err = -EFAULT; \ | |
170 | break; \ | |
171 | default: \ | |
172 | __get_user_unknown(); \ | |
173 | break; \ | |
174 | } \ | |
175 | } while (0) | |
176 | ||
177 | #define __get_user_nocheck(x, ptr, size) \ | |
178 | ({ \ | |
179 | long __gu_err = 0; \ | |
180 | __get_user_common((x), size, ptr); \ | |
181 | __gu_err; \ | |
182 | }) | |
183 | ||
184 | #define __get_user_check(x, ptr, size) \ | |
185 | ({ \ | |
186 | long __gu_err = -EFAULT; \ | |
187 | const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ | |
188 | \ | |
189 | if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \ | |
190 | __get_user_common((x), size, __gu_ptr); \ | |
c2f18fa4 AV |
191 | else \ |
192 | (x) = 0; \ | |
ffa818b4 CL |
193 | \ |
194 | __gu_err; \ | |
195 | }) | |
196 | ||
197 | #define __get_user_asm(val, insn, addr) \ | |
198 | { \ | |
199 | long __gu_tmp; \ | |
200 | \ | |
201 | __asm__ __volatile__( \ | |
202 | "1:" insn " %1, %3\n" \ | |
203 | "2:\n" \ | |
204 | ".section .fixup,\"ax\"\n" \ | |
205 | "3:li %0, %4\n" \ | |
c2f18fa4 | 206 | "li %1, 0\n" \ |
ffa818b4 CL |
207 | "j 2b\n" \ |
208 | ".previous\n" \ | |
209 | ".section __ex_table,\"a\"\n" \ | |
210 | ".word 1b, 3b\n" \ | |
211 | ".previous\n" \ | |
212 | : "=r" (__gu_err), "=r" (__gu_tmp) \ | |
213 | : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \ | |
214 | \ | |
215 | (val) = (__typeof__(*(addr))) __gu_tmp; \ | |
216 | } | |
217 | ||
218 | /* | |
219 | * Yuck. We need two variants, one for 64bit operation and one | |
220 | * for 32 bit mode and old iron. | |
221 | */ | |
222 | #define __put_user_nocheck(val, ptr, size) \ | |
223 | ({ \ | |
224 | __typeof__(*(ptr)) __pu_val; \ | |
225 | long __pu_err = 0; \ | |
226 | \ | |
227 | __pu_val = (val); \ | |
228 | switch (size) { \ | |
229 | case 1: \ | |
230 | __put_user_asm("sb", ptr); \ | |
231 | break; \ | |
232 | case 2: \ | |
233 | __put_user_asm("sh", ptr); \ | |
234 | break; \ | |
235 | case 4: \ | |
236 | __put_user_asm("sw", ptr); \ | |
237 | break; \ | |
238 | case 8: \ | |
239 | if ((__copy_to_user((void *)ptr, &__pu_val, 8)) == 0) \ | |
240 | __pu_err = 0; \ | |
241 | else \ | |
242 | __pu_err = -EFAULT; \ | |
243 | break; \ | |
244 | default: \ | |
245 | __put_user_unknown(); \ | |
246 | break; \ | |
247 | } \ | |
248 | __pu_err; \ | |
249 | }) | |
250 | ||
251 | ||
252 | #define __put_user_check(val, ptr, size) \ | |
253 | ({ \ | |
254 | __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ | |
255 | __typeof__(*(ptr)) __pu_val = (val); \ | |
256 | long __pu_err = -EFAULT; \ | |
257 | \ | |
258 | if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \ | |
259 | switch (size) { \ | |
260 | case 1: \ | |
261 | __put_user_asm("sb", __pu_addr); \ | |
262 | break; \ | |
263 | case 2: \ | |
264 | __put_user_asm("sh", __pu_addr); \ | |
265 | break; \ | |
266 | case 4: \ | |
267 | __put_user_asm("sw", __pu_addr); \ | |
268 | break; \ | |
269 | case 8: \ | |
270 | if ((__copy_to_user((void *)__pu_addr, &__pu_val, 8)) == 0)\ | |
271 | __pu_err = 0; \ | |
272 | else \ | |
273 | __pu_err = -EFAULT; \ | |
274 | break; \ | |
275 | default: \ | |
276 | __put_user_unknown(); \ | |
277 | break; \ | |
278 | } \ | |
279 | } \ | |
280 | __pu_err; \ | |
281 | }) | |
282 | ||
283 | #define __put_user_asm(insn, ptr) \ | |
284 | __asm__ __volatile__( \ | |
285 | "1:" insn " %2, %3\n" \ | |
286 | "2:\n" \ | |
287 | ".section .fixup,\"ax\"\n" \ | |
288 | "3:li %0, %4\n" \ | |
289 | "j 2b\n" \ | |
290 | ".previous\n" \ | |
291 | ".section __ex_table,\"a\"\n" \ | |
292 | ".word 1b, 3b\n" \ | |
293 | ".previous\n" \ | |
294 | : "=r" (__pu_err) \ | |
295 | : "0" (0), "r" (__pu_val), "o" (__m(ptr)), \ | |
296 | "i" (-EFAULT)); | |
297 | ||
298 | extern void __put_user_unknown(void); | |
299 | extern int __copy_tofrom_user(void *to, const void *from, unsigned long len); | |
300 | ||
301 | static inline unsigned long | |
302 | copy_from_user(void *to, const void *from, unsigned long len) | |
303 | { | |
b615e3c7 | 304 | unsigned long res = len; |
ffa818b4 | 305 | |
b615e3c7 AV |
306 | if (likely(access_ok(VERIFY_READ, from, len))) |
307 | res = __copy_tofrom_user(to, from, len); | |
ffa818b4 | 308 | |
b615e3c7 AV |
309 | if (unlikely(res)) |
310 | memset(to + (len - res), 0, res); | |
311 | ||
312 | return res; | |
ffa818b4 CL |
313 | } |
314 | ||
315 | static inline unsigned long | |
316 | copy_to_user(void *to, const void *from, unsigned long len) | |
317 | { | |
b615e3c7 AV |
318 | if (likely(access_ok(VERIFY_WRITE, to, len))) |
319 | len = __copy_tofrom_user(to, from, len); | |
ffa818b4 | 320 | |
ffa818b4 CL |
321 | return len; |
322 | } | |
6bc9a396 | 323 | |
b615e3c7 AV |
324 | static inline unsigned long |
325 | __copy_from_user(void *to, const void *from, unsigned long len) | |
326 | { | |
327 | unsigned long left = __copy_tofrom_user(to, from, len); | |
328 | if (unlikely(left)) | |
329 | memset(to + (len - left), 0, left); | |
330 | return left; | |
331 | } | |
6bc9a396 | 332 | |
ffa818b4 CL |
333 | #define __copy_to_user(to, from, len) \ |
334 | __copy_tofrom_user((to), (from), (len)) | |
6bc9a396 | 335 | |
ffa818b4 CL |
336 | static inline unsigned long |
337 | __copy_to_user_inatomic(void *to, const void *from, unsigned long len) | |
338 | { | |
339 | return __copy_to_user(to, from, len); | |
340 | } | |
6bc9a396 | 341 | |
ffa818b4 CL |
342 | static inline unsigned long |
343 | __copy_from_user_inatomic(void *to, const void *from, unsigned long len) | |
344 | { | |
b615e3c7 | 345 | return __copy_tofrom_user(to, from, len); |
ffa818b4 CL |
346 | } |
347 | ||
b615e3c7 | 348 | #define __copy_in_user(to, from, len) __copy_tofrom_user(to, from, len) |
ffa818b4 CL |
349 | |
350 | static inline unsigned long | |
351 | copy_in_user(void *to, const void *from, unsigned long len) | |
352 | { | |
353 | if (access_ok(VERIFY_READ, from, len) && | |
354 | access_ok(VERFITY_WRITE, to, len)) | |
b615e3c7 | 355 | return __copy_tofrom_user(to, from, len); |
ffa818b4 CL |
356 | } |
357 | ||
358 | /* | |
359 | * __clear_user: - Zero a block of memory in user space, with less checking. | |
360 | * @to: Destination address, in user space. | |
361 | * @n: Number of bytes to zero. | |
362 | * | |
363 | * Zero a block of memory in user space. Caller must check | |
364 | * the specified block with access_ok() before calling this function. | |
365 | * | |
366 | * Returns number of bytes that could not be cleared. | |
367 | * On success, this will be zero. | |
368 | */ | |
369 | extern unsigned long __clear_user(void __user *src, unsigned long size); | |
370 | ||
371 | static inline unsigned long clear_user(char *src, unsigned long size) | |
372 | { | |
373 | if (access_ok(VERIFY_WRITE, src, size)) | |
374 | return __clear_user(src, size); | |
375 | ||
376 | return -EFAULT; | |
377 | } | |
378 | /* | |
379 | * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking. | |
380 | * @dst: Destination address, in kernel space. This buffer must be at | |
381 | * least @count bytes long. | |
382 | * @src: Source address, in user space. | |
383 | * @count: Maximum number of bytes to copy, including the trailing NUL. | |
384 | * | |
385 | * Copies a NUL-terminated string from userspace to kernel space. | |
386 | * Caller must check the specified block with access_ok() before calling | |
387 | * this function. | |
388 | * | |
389 | * On success, returns the length of the string (not including the trailing | |
390 | * NUL). | |
391 | * | |
392 | * If access to userspace fails, returns -EFAULT (some data may have been | |
393 | * copied). | |
394 | * | |
395 | * If @count is smaller than the length of the string, copies @count bytes | |
396 | * and returns @count. | |
397 | */ | |
398 | extern int __strncpy_from_user(char *dst, const char *src, long len); | |
399 | ||
400 | static inline int strncpy_from_user(char *dst, const char *src, long len) | |
401 | { | |
402 | if (access_ok(VERIFY_READ, src, 1)) | |
403 | return __strncpy_from_user(dst, src, len); | |
404 | ||
405 | return -EFAULT; | |
406 | } | |
407 | ||
408 | extern int __strlen_user(const char *src); | |
409 | static inline long strlen_user(const char __user *src) | |
410 | { | |
411 | return __strlen_user(src); | |
412 | } | |
413 | ||
414 | extern int __strnlen_user(const char *str, long len); | |
415 | static inline long strnlen_user(const char __user *str, long len) | |
416 | { | |
417 | if (!access_ok(VERIFY_READ, str, 0)) | |
418 | return 0; | |
419 | else | |
420 | return __strnlen_user(str, len); | |
421 | } | |
422 | ||
423 | struct exception_table_entry { | |
424 | unsigned long insn; | |
425 | unsigned long fixup; | |
426 | }; | |
427 | ||
428 | extern int fixup_exception(struct pt_regs *regs); | |
6bc9a396 | 429 | |
ffa818b4 | 430 | #endif /* __SCORE_UACCESS_H */ |
6bc9a396 | 431 |