]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - arch/arm/include/asm/uaccess.h
projects / mirror_ubuntu-artful-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[mirror_ubuntu-artful-kernel.git] / arch / arm / include / asm / uaccess.h
1 /*
2 * arch/arm/include/asm/uaccess.h
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8 #ifndef _ASMARM_UACCESS_H
9 #define _ASMARM_UACCESS_H
10
11 /*
12 * User space memory access functions
13 */
14 #include <linux/string.h>
15 #include <asm/memory.h>
16 #include <asm/domain.h>
17 #include <asm/unified.h>
18 #include <asm/compiler.h>
19
20 #include <asm/extable.h>
21
22 /*
23 * These two functions allow hooking accesses to userspace to increase
24 * system integrity by ensuring that the kernel can not inadvertantly
25 * perform such accesses (eg, via list poison values) which could then
26 * be exploited for priviledge escalation.
27 */
28 static inline unsigned int uaccess_save_and_enable(void)
29 {
30 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
31 unsigned int old_domain = get_domain();
32
33 /* Set the current domain access to permit user accesses */
34 set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
35 domain_val(DOMAIN_USER, DOMAIN_CLIENT));
36
37 return old_domain;
38 #else
39 return 0;
40 #endif
41 }
42
43 static inline void uaccess_restore(unsigned int flags)
44 {
45 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
46 /* Restore the user access mask */
47 set_domain(flags);
48 #endif
49 }
50
51 /*
52 * These two are intentionally not defined anywhere - if the kernel
53 * code generates any references to them, that's a bug.
54 */
55 extern int __get_user_bad(void);
56 extern int __put_user_bad(void);
57
58 /*
59 * Note that this is actually 0x1,0000,0000
60 */
61 #define KERNEL_DS 0x00000000
62 #define get_ds() (KERNEL_DS)
63
64 #ifdef CONFIG_MMU
65
66 #define USER_DS TASK_SIZE
67 #define get_fs() (current_thread_info()->addr_limit)
68
69 static inline void set_fs(mm_segment_t fs)
70 {
71 current_thread_info()->addr_limit = fs;
72 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
73 }
74
75 #define segment_eq(a, b) ((a) == (b))
76
77 /* We use 33-bit arithmetic here... */
78 #define __range_ok(addr, size) ({ \
79 unsigned long flag, roksum; \
80 __chk_user_ptr(addr); \
81 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
82 : "=&r" (flag), "=&r" (roksum) \
83 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
84 : "cc"); \
85 flag; })
86
87 /*
88 * Single-value transfer routines. They automatically use the right
89 * size if we just have the right pointer type. Note that the functions
90 * which read from user space (*get_*) need to take care not to leak
91 * kernel data even if the calling code is buggy and fails to check
92 * the return value. This means zeroing out the destination variable
93 * or buffer on error. Normally this is done out of line by the
94 * fixup code, but there are a few places where it intrudes on the
95 * main code path. When we only write to user space, there is no
96 * problem.
97 */
98 extern int __get_user_1(void *);
99 extern int __get_user_2(void *);
100 extern int __get_user_4(void *);
101 extern int __get_user_32t_8(void *);
102 extern int __get_user_8(void *);
103 extern int __get_user_64t_1(void *);
104 extern int __get_user_64t_2(void *);
105 extern int __get_user_64t_4(void *);
106
107 #define __GUP_CLOBBER_1 "lr", "cc"
108 #ifdef CONFIG_CPU_USE_DOMAINS
109 #define __GUP_CLOBBER_2 "ip", "lr", "cc"
110 #else
111 #define __GUP_CLOBBER_2 "lr", "cc"
112 #endif
113 #define __GUP_CLOBBER_4 "lr", "cc"
114 #define __GUP_CLOBBER_32t_8 "lr", "cc"
115 #define __GUP_CLOBBER_8 "lr", "cc"
116
117 #define __get_user_x(__r2, __p, __e, __l, __s) \
118 __asm__ __volatile__ ( \
119 __asmeq("%0", "r0") __asmeq("%1", "r2") \
120 __asmeq("%3", "r1") \
121 "bl __get_user_" #__s \
122 : "=&r" (__e), "=r" (__r2) \
123 : "0" (__p), "r" (__l) \
124 : __GUP_CLOBBER_##__s)
125
126 /* narrowing a double-word get into a single 32bit word register: */
127 #ifdef __ARMEB__
128 #define __get_user_x_32t(__r2, __p, __e, __l, __s) \
129 __get_user_x(__r2, __p, __e, __l, 32t_8)
130 #else
131 #define __get_user_x_32t __get_user_x
132 #endif
133
134 /*
135 * storing result into proper least significant word of 64bit target var,
136 * different only for big endian case where 64 bit __r2 lsw is r3:
137 */
138 #ifdef __ARMEB__
139 #define __get_user_x_64t(__r2, __p, __e, __l, __s) \
140 __asm__ __volatile__ ( \
141 __asmeq("%0", "r0") __asmeq("%1", "r2") \
142 __asmeq("%3", "r1") \
143 "bl __get_user_64t_" #__s \
144 : "=&r" (__e), "=r" (__r2) \
145 : "0" (__p), "r" (__l) \
146 : __GUP_CLOBBER_##__s)
147 #else
148 #define __get_user_x_64t __get_user_x
149 #endif
150
151
152 #define __get_user_check(x, p) \
153 ({ \
154 unsigned long __limit = current_thread_info()->addr_limit - 1; \
155 register const typeof(*(p)) __user *__p asm("r0") = (p);\
156 register typeof(x) __r2 asm("r2"); \
157 register unsigned long __l asm("r1") = __limit; \
158 register int __e asm("r0"); \
159 unsigned int __ua_flags = uaccess_save_and_enable(); \
160 switch (sizeof(*(__p))) { \
161 case 1: \
162 if (sizeof((x)) >= 8) \
163 __get_user_x_64t(__r2, __p, __e, __l, 1); \
164 else \
165 __get_user_x(__r2, __p, __e, __l, 1); \
166 break; \
167 case 2: \
168 if (sizeof((x)) >= 8) \
169 __get_user_x_64t(__r2, __p, __e, __l, 2); \
170 else \
171 __get_user_x(__r2, __p, __e, __l, 2); \
172 break; \
173 case 4: \
174 if (sizeof((x)) >= 8) \
175 __get_user_x_64t(__r2, __p, __e, __l, 4); \
176 else \
177 __get_user_x(__r2, __p, __e, __l, 4); \
178 break; \
179 case 8: \
180 if (sizeof((x)) < 8) \
181 __get_user_x_32t(__r2, __p, __e, __l, 4); \
182 else \
183 __get_user_x(__r2, __p, __e, __l, 8); \
184 break; \
185 default: __e = __get_user_bad(); break; \
186 } \
187 uaccess_restore(__ua_flags); \
188 x = (typeof(*(p))) __r2; \
189 __e; \
190 })
191
192 #define get_user(x, p) \
193 ({ \
194 might_fault(); \
195 __get_user_check(x, p); \
196 })
197
198 extern int __put_user_1(void *, unsigned int);
199 extern int __put_user_2(void *, unsigned int);
200 extern int __put_user_4(void *, unsigned int);
201 extern int __put_user_8(void *, unsigned long long);
202
203 #define __put_user_check(__pu_val, __ptr, __err, __s) \
204 ({ \
205 unsigned long __limit = current_thread_info()->addr_limit - 1; \
206 register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
207 register const void __user *__p asm("r0") = __ptr; \
208 register unsigned long __l asm("r1") = __limit; \
209 register int __e asm("r0"); \
210 __asm__ __volatile__ ( \
211 __asmeq("%0", "r0") __asmeq("%2", "r2") \
212 __asmeq("%3", "r1") \
213 "bl __put_user_" #__s \
214 : "=&r" (__e) \
215 : "0" (__p), "r" (__r2), "r" (__l) \
216 : "ip", "lr", "cc"); \
217 __err = __e; \
218 })
219
220 #else /* CONFIG_MMU */
221
222 /*
223 * uClinux has only one addr space, so has simplified address limits.
224 */
225 #define USER_DS KERNEL_DS
226
227 #define segment_eq(a, b) (1)
228 #define __addr_ok(addr) ((void)(addr), 1)
229 #define __range_ok(addr, size) ((void)(addr), 0)
230 #define get_fs() (KERNEL_DS)
231
232 static inline void set_fs(mm_segment_t fs)
233 {
234 }
235
236 #define get_user(x, p) __get_user(x, p)
237 #define __put_user_check __put_user_nocheck
238
239 #endif /* CONFIG_MMU */
240
241 #define access_ok(type, addr, size) (__range_ok(addr, size) == 0)
242
243 #define user_addr_max() \
244 (uaccess_kernel() ? ~0UL : get_fs())
245
246 /*
247 * The "__xxx" versions of the user access functions do not verify the
248 * address space - it must have been done previously with a separate
249 * "access_ok()" call.
250 *
251 * The "xxx_error" versions set the third argument to EFAULT if an
252 * error occurs, and leave it unchanged on success. Note that these
253 * versions are void (ie, don't return a value as such).
254 */
255 #define __get_user(x, ptr) \
256 ({ \
257 long __gu_err = 0; \
258 __get_user_err((x), (ptr), __gu_err); \
259 __gu_err; \
260 })
261
262 #define __get_user_error(x, ptr, err) \
263 ({ \
264 __get_user_err((x), (ptr), err); \
265 (void) 0; \
266 })
267
268 #define __get_user_err(x, ptr, err) \
269 do { \
270 unsigned long __gu_addr = (unsigned long)(ptr); \
271 unsigned long __gu_val; \
272 unsigned int __ua_flags; \
273 __chk_user_ptr(ptr); \
274 might_fault(); \
275 __ua_flags = uaccess_save_and_enable(); \
276 switch (sizeof(*(ptr))) { \
277 case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
278 case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
279 case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
280 default: (__gu_val) = __get_user_bad(); \
281 } \
282 uaccess_restore(__ua_flags); \
283 (x) = (__typeof__(*(ptr)))__gu_val; \
284 } while (0)
285
286 #define __get_user_asm(x, addr, err, instr) \
287 __asm__ __volatile__( \
288 "1: " TUSER(instr) " %1, [%2], #0\n" \
289 "2:\n" \
290 " .pushsection .text.fixup,\"ax\"\n" \
291 " .align 2\n" \
292 "3: mov %0, %3\n" \
293 " mov %1, #0\n" \
294 " b 2b\n" \
295 " .popsection\n" \
296 " .pushsection __ex_table,\"a\"\n" \
297 " .align 3\n" \
298 " .long 1b, 3b\n" \
299 " .popsection" \
300 : "+r" (err), "=&r" (x) \
301 : "r" (addr), "i" (-EFAULT) \
302 : "cc")
303
304 #define __get_user_asm_byte(x, addr, err) \
305 __get_user_asm(x, addr, err, ldrb)
306
307 #ifndef __ARMEB__
308 #define __get_user_asm_half(x, __gu_addr, err) \
309 ({ \
310 unsigned long __b1, __b2; \
311 __get_user_asm_byte(__b1, __gu_addr, err); \
312 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
313 (x) = __b1 | (__b2 << 8); \
314 })
315 #else
316 #define __get_user_asm_half(x, __gu_addr, err) \
317 ({ \
318 unsigned long __b1, __b2; \
319 __get_user_asm_byte(__b1, __gu_addr, err); \
320 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
321 (x) = (__b1 << 8) | __b2; \
322 })
323 #endif
324
325 #define __get_user_asm_word(x, addr, err) \
326 __get_user_asm(x, addr, err, ldr)
327
328
329 #define __put_user_switch(x, ptr, __err, __fn) \
330 do { \
331 const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
332 __typeof__(*(ptr)) __pu_val = (x); \
333 unsigned int __ua_flags; \
334 might_fault(); \
335 __ua_flags = uaccess_save_and_enable(); \
336 switch (sizeof(*(ptr))) { \
337 case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
338 case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
339 case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
340 case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
341 default: __err = __put_user_bad(); break; \
342 } \
343 uaccess_restore(__ua_flags); \
344 } while (0)
345
346 #define put_user(x, ptr) \
347 ({ \
348 int __pu_err = 0; \
349 __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
350 __pu_err; \
351 })
352
353 #define __put_user(x, ptr) \
354 ({ \
355 long __pu_err = 0; \
356 __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
357 __pu_err; \
358 })
359
360 #define __put_user_error(x, ptr, err) \
361 ({ \
362 __put_user_switch((x), (ptr), (err), __put_user_nocheck); \
363 (void) 0; \
364 })
365
366 #define __put_user_nocheck(x, __pu_ptr, __err, __size) \
367 do { \
368 unsigned long __pu_addr = (unsigned long)__pu_ptr; \
369 __put_user_nocheck_##__size(x, __pu_addr, __err); \
370 } while (0)
371
372 #define __put_user_nocheck_1 __put_user_asm_byte
373 #define __put_user_nocheck_2 __put_user_asm_half
374 #define __put_user_nocheck_4 __put_user_asm_word
375 #define __put_user_nocheck_8 __put_user_asm_dword
376
377 #define __put_user_asm(x, __pu_addr, err, instr) \
378 __asm__ __volatile__( \
379 "1: " TUSER(instr) " %1, [%2], #0\n" \
380 "2:\n" \
381 " .pushsection .text.fixup,\"ax\"\n" \
382 " .align 2\n" \
383 "3: mov %0, %3\n" \
384 " b 2b\n" \
385 " .popsection\n" \
386 " .pushsection __ex_table,\"a\"\n" \
387 " .align 3\n" \
388 " .long 1b, 3b\n" \
389 " .popsection" \
390 : "+r" (err) \
391 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
392 : "cc")
393
394 #define __put_user_asm_byte(x, __pu_addr, err) \
395 __put_user_asm(x, __pu_addr, err, strb)
396
397 #ifndef __ARMEB__
398 #define __put_user_asm_half(x, __pu_addr, err) \
399 ({ \
400 unsigned long __temp = (__force unsigned long)(x); \
401 __put_user_asm_byte(__temp, __pu_addr, err); \
402 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
403 })
404 #else
405 #define __put_user_asm_half(x, __pu_addr, err) \
406 ({ \
407 unsigned long __temp = (__force unsigned long)(x); \
408 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
409 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
410 })
411 #endif
412
413 #define __put_user_asm_word(x, __pu_addr, err) \
414 __put_user_asm(x, __pu_addr, err, str)
415
416 #ifndef __ARMEB__
417 #define __reg_oper0 "%R2"
418 #define __reg_oper1 "%Q2"
419 #else
420 #define __reg_oper0 "%Q2"
421 #define __reg_oper1 "%R2"
422 #endif
423
424 #define __put_user_asm_dword(x, __pu_addr, err) \
425 __asm__ __volatile__( \
426 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
427 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
428 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
429 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
430 "3:\n" \
431 " .pushsection .text.fixup,\"ax\"\n" \
432 " .align 2\n" \
433 "4: mov %0, %3\n" \
434 " b 3b\n" \
435 " .popsection\n" \
436 " .pushsection __ex_table,\"a\"\n" \
437 " .align 3\n" \
438 " .long 1b, 4b\n" \
439 " .long 2b, 4b\n" \
440 " .popsection" \
441 : "+r" (err), "+r" (__pu_addr) \
442 : "r" (x), "i" (-EFAULT) \
443 : "cc")
444
445
446 #ifdef CONFIG_MMU
447 extern unsigned long __must_check
448 arm_copy_from_user(void *to, const void __user *from, unsigned long n);
449
450 static inline unsigned long __must_check
451 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
452 {
453 unsigned int __ua_flags;
454
455 __ua_flags = uaccess_save_and_enable();
456 n = arm_copy_from_user(to, from, n);
457 uaccess_restore(__ua_flags);
458 return n;
459 }
460
461 extern unsigned long __must_check
462 arm_copy_to_user(void __user *to, const void *from, unsigned long n);
463 extern unsigned long __must_check
464 __copy_to_user_std(void __user *to, const void *from, unsigned long n);
465
466 static inline unsigned long __must_check
467 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
468 {
469 #ifndef CONFIG_UACCESS_WITH_MEMCPY
470 unsigned int __ua_flags;
471 __ua_flags = uaccess_save_and_enable();
472 n = arm_copy_to_user(to, from, n);
473 uaccess_restore(__ua_flags);
474 return n;
475 #else
476 return arm_copy_to_user(to, from, n);
477 #endif
478 }
479
480 extern unsigned long __must_check
481 arm_clear_user(void __user *addr, unsigned long n);
482 extern unsigned long __must_check
483 __clear_user_std(void __user *addr, unsigned long n);
484
485 static inline unsigned long __must_check
486 __clear_user(void __user *addr, unsigned long n)
487 {
488 unsigned int __ua_flags = uaccess_save_and_enable();
489 n = arm_clear_user(addr, n);
490 uaccess_restore(__ua_flags);
491 return n;
492 }
493
494 #else
495 static inline unsigned long
496 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
497 {
498 memcpy(to, (const void __force *)from, n);
499 return 0;
500 }
501 static inline unsigned long
502 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
503 {
504 memcpy((void __force *)to, from, n);
505 return 0;
506 }
507 #define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
508 #endif
509 #define INLINE_COPY_TO_USER
510 #define INLINE_COPY_FROM_USER
511
512 static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
513 {
514 if (access_ok(VERIFY_WRITE, to, n))
515 n = __clear_user(to, n);
516 return n;
517 }
518
519 /* These are from lib/ code, and use __get_user() and friends */
520 extern long strncpy_from_user(char *dest, const char __user *src, long count);
521
522 extern __must_check long strnlen_user(const char __user *str, long n);
523
524 #endif /* _ASMARM_UACCESS_H */
Ubuntu Artful kernel mirror