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-rw-r--r--include/asm-arm/uaccess.h438
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diff --git a/include/asm-arm/uaccess.h b/include/asm-arm/uaccess.h
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1/*
2 * linux/include/asm-arm/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/sched.h>
15#include <asm/errno.h>
16#include <asm/memory.h>
17#include <asm/domain.h>
18#include <asm/system.h>
19
20#define VERIFY_READ 0
21#define VERIFY_WRITE 1
22
23/*
24 * The exception table consists of pairs of addresses: the first is the
25 * address of an instruction that is allowed to fault, and the second is
26 * the address at which the program should continue. No registers are
27 * modified, so it is entirely up to the continuation code to figure out
28 * what to do.
29 *
30 * All the routines below use bits of fixup code that are out of line
31 * with the main instruction path. This means when everything is well,
32 * we don't even have to jump over them. Further, they do not intrude
33 * on our cache or tlb entries.
34 */
35
36struct exception_table_entry
37{
38 unsigned long insn, fixup;
39};
40
41extern int fixup_exception(struct pt_regs *regs);
42
43/*
44 * Note that this is actually 0x1,0000,0000
45 */
46#define KERNEL_DS 0x00000000
47#define USER_DS TASK_SIZE
48
49#define get_ds() (KERNEL_DS)
50#define get_fs() (current_thread_info()->addr_limit)
51
52static inline void set_fs (mm_segment_t fs)
53{
54 current_thread_info()->addr_limit = fs;
55 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
56}
57
58#define segment_eq(a,b) ((a) == (b))
59
60#define __addr_ok(addr) ({ \
61 unsigned long flag; \
62 __asm__("cmp %2, %0; movlo %0, #0" \
63 : "=&r" (flag) \
64 : "0" (current_thread_info()->addr_limit), "r" (addr) \
65 : "cc"); \
66 (flag == 0); })
67
68/* We use 33-bit arithmetic here... */
69#define __range_ok(addr,size) ({ \
70 unsigned long flag, sum; \
71 __chk_user_ptr(addr); \
72 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
73 : "=&r" (flag), "=&r" (sum) \
74 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
75 : "cc"); \
76 flag; })
77
78#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
79
80/* this function will go away soon - use access_ok() instead */
81static inline int __deprecated verify_area(int type, const void __user *addr, unsigned long size)
82{
83 return access_ok(type, addr, size) ? 0 : -EFAULT;
84}
85
86/*
87 * Single-value transfer routines. They automatically use the right
88 * size if we just have the right pointer type. Note that the functions
89 * which read from user space (*get_*) need to take care not to leak
90 * kernel data even if the calling code is buggy and fails to check
91 * the return value. This means zeroing out the destination variable
92 * or buffer on error. Normally this is done out of line by the
93 * fixup code, but there are a few places where it intrudes on the
94 * main code path. When we only write to user space, there is no
95 * problem.
96 *
97 * The "__xxx" versions of the user access functions do not verify the
98 * address space - it must have been done previously with a separate
99 * "access_ok()" call.
100 *
101 * The "xxx_error" versions set the third argument to EFAULT if an
102 * error occurs, and leave it unchanged on success. Note that these
103 * versions are void (ie, don't return a value as such).
104 */
105
106extern int __get_user_1(void *);
107extern int __get_user_2(void *);
108extern int __get_user_4(void *);
109extern int __get_user_8(void *);
110extern int __get_user_bad(void);
111
112#define __get_user_x(__r2,__p,__e,__s,__i...) \
113 __asm__ __volatile__ ( \
114 __asmeq("%0", "r0") __asmeq("%1", "r2") \
115 "bl __get_user_" #__s \
116 : "=&r" (__e), "=r" (__r2) \
117 : "0" (__p) \
118 : __i, "cc")
119
120#define get_user(x,p) \
121 ({ \
122 const register typeof(*(p)) __user *__p asm("r0") = (p);\
123 register typeof(*(p)) __r2 asm("r2"); \
124 register int __e asm("r0"); \
125 switch (sizeof(*(__p))) { \
126 case 1: \
127 __get_user_x(__r2, __p, __e, 1, "lr"); \
128 break; \
129 case 2: \
130 __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \
131 break; \
132 case 4: \
133 __get_user_x(__r2, __p, __e, 4, "lr"); \
134 break; \
135 case 8: \
136 __get_user_x(__r2, __p, __e, 8, "lr"); \
137 break; \
138 default: __e = __get_user_bad(); break; \
139 } \
140 x = __r2; \
141 __e; \
142 })
143
144#define __get_user(x,ptr) \
145({ \
146 long __gu_err = 0; \
147 __get_user_err((x),(ptr),__gu_err); \
148 __gu_err; \
149})
150
151#define __get_user_error(x,ptr,err) \
152({ \
153 __get_user_err((x),(ptr),err); \
154 (void) 0; \
155})
156
157#define __get_user_err(x,ptr,err) \
158do { \
159 unsigned long __gu_addr = (unsigned long)(ptr); \
160 unsigned long __gu_val; \
161 __chk_user_ptr(ptr); \
162 switch (sizeof(*(ptr))) { \
163 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
164 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
165 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
166 default: (__gu_val) = __get_user_bad(); \
167 } \
168 (x) = (__typeof__(*(ptr)))__gu_val; \
169} while (0)
170
171#define __get_user_asm_byte(x,addr,err) \
172 __asm__ __volatile__( \
173 "1: ldrbt %1,[%2],#0\n" \
174 "2:\n" \
175 " .section .fixup,\"ax\"\n" \
176 " .align 2\n" \
177 "3: mov %0, %3\n" \
178 " mov %1, #0\n" \
179 " b 2b\n" \
180 " .previous\n" \
181 " .section __ex_table,\"a\"\n" \
182 " .align 3\n" \
183 " .long 1b, 3b\n" \
184 " .previous" \
185 : "+r" (err), "=&r" (x) \
186 : "r" (addr), "i" (-EFAULT) \
187 : "cc")
188
189#ifndef __ARMEB__
190#define __get_user_asm_half(x,__gu_addr,err) \
191({ \
192 unsigned long __b1, __b2; \
193 __get_user_asm_byte(__b1, __gu_addr, err); \
194 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
195 (x) = __b1 | (__b2 << 8); \
196})
197#else
198#define __get_user_asm_half(x,__gu_addr,err) \
199({ \
200 unsigned long __b1, __b2; \
201 __get_user_asm_byte(__b1, __gu_addr, err); \
202 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
203 (x) = (__b1 << 8) | __b2; \
204})
205#endif
206
207#define __get_user_asm_word(x,addr,err) \
208 __asm__ __volatile__( \
209 "1: ldrt %1,[%2],#0\n" \
210 "2:\n" \
211 " .section .fixup,\"ax\"\n" \
212 " .align 2\n" \
213 "3: mov %0, %3\n" \
214 " mov %1, #0\n" \
215 " b 2b\n" \
216 " .previous\n" \
217 " .section __ex_table,\"a\"\n" \
218 " .align 3\n" \
219 " .long 1b, 3b\n" \
220 " .previous" \
221 : "+r" (err), "=&r" (x) \
222 : "r" (addr), "i" (-EFAULT) \
223 : "cc")
224
225extern int __put_user_1(void *, unsigned int);
226extern int __put_user_2(void *, unsigned int);
227extern int __put_user_4(void *, unsigned int);
228extern int __put_user_8(void *, unsigned long long);
229extern int __put_user_bad(void);
230
231#define __put_user_x(__r2,__p,__e,__s) \
232 __asm__ __volatile__ ( \
233 __asmeq("%0", "r0") __asmeq("%2", "r2") \
234 "bl __put_user_" #__s \
235 : "=&r" (__e) \
236 : "0" (__p), "r" (__r2) \
237 : "ip", "lr", "cc")
238
239#define put_user(x,p) \
240 ({ \
241 const register typeof(*(p)) __r2 asm("r2") = (x); \
242 const register typeof(*(p)) __user *__p asm("r0") = (p);\
243 register int __e asm("r0"); \
244 switch (sizeof(*(__p))) { \
245 case 1: \
246 __put_user_x(__r2, __p, __e, 1); \
247 break; \
248 case 2: \
249 __put_user_x(__r2, __p, __e, 2); \
250 break; \
251 case 4: \
252 __put_user_x(__r2, __p, __e, 4); \
253 break; \
254 case 8: \
255 __put_user_x(__r2, __p, __e, 8); \
256 break; \
257 default: __e = __put_user_bad(); break; \
258 } \
259 __e; \
260 })
261
262#define __put_user(x,ptr) \
263({ \
264 long __pu_err = 0; \
265 __put_user_err((x),(ptr),__pu_err); \
266 __pu_err; \
267})
268
269#define __put_user_error(x,ptr,err) \
270({ \
271 __put_user_err((x),(ptr),err); \
272 (void) 0; \
273})
274
275#define __put_user_err(x,ptr,err) \
276do { \
277 unsigned long __pu_addr = (unsigned long)(ptr); \
278 __typeof__(*(ptr)) __pu_val = (x); \
279 __chk_user_ptr(ptr); \
280 switch (sizeof(*(ptr))) { \
281 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
282 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
283 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
284 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
285 default: __put_user_bad(); \
286 } \
287} while (0)
288
289#define __put_user_asm_byte(x,__pu_addr,err) \
290 __asm__ __volatile__( \
291 "1: strbt %1,[%2],#0\n" \
292 "2:\n" \
293 " .section .fixup,\"ax\"\n" \
294 " .align 2\n" \
295 "3: mov %0, %3\n" \
296 " b 2b\n" \
297 " .previous\n" \
298 " .section __ex_table,\"a\"\n" \
299 " .align 3\n" \
300 " .long 1b, 3b\n" \
301 " .previous" \
302 : "+r" (err) \
303 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
304 : "cc")
305
306#ifndef __ARMEB__
307#define __put_user_asm_half(x,__pu_addr,err) \
308({ \
309 unsigned long __temp = (unsigned long)(x); \
310 __put_user_asm_byte(__temp, __pu_addr, err); \
311 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
312})
313#else
314#define __put_user_asm_half(x,__pu_addr,err) \
315({ \
316 unsigned long __temp = (unsigned long)(x); \
317 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
318 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
319})
320#endif
321
322#define __put_user_asm_word(x,__pu_addr,err) \
323 __asm__ __volatile__( \
324 "1: strt %1,[%2],#0\n" \
325 "2:\n" \
326 " .section .fixup,\"ax\"\n" \
327 " .align 2\n" \
328 "3: mov %0, %3\n" \
329 " b 2b\n" \
330 " .previous\n" \
331 " .section __ex_table,\"a\"\n" \
332 " .align 3\n" \
333 " .long 1b, 3b\n" \
334 " .previous" \
335 : "+r" (err) \
336 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
337 : "cc")
338
339#ifndef __ARMEB__
340#define __reg_oper0 "%R2"
341#define __reg_oper1 "%Q2"
342#else
343#define __reg_oper0 "%Q2"
344#define __reg_oper1 "%R2"
345#endif
346
347#define __put_user_asm_dword(x,__pu_addr,err) \
348 __asm__ __volatile__( \
349 "1: strt " __reg_oper1 ", [%1], #4\n" \
350 "2: strt " __reg_oper0 ", [%1], #0\n" \
351 "3:\n" \
352 " .section .fixup,\"ax\"\n" \
353 " .align 2\n" \
354 "4: mov %0, %3\n" \
355 " b 3b\n" \
356 " .previous\n" \
357 " .section __ex_table,\"a\"\n" \
358 " .align 3\n" \
359 " .long 1b, 4b\n" \
360 " .long 2b, 4b\n" \
361 " .previous" \
362 : "+r" (err), "+r" (__pu_addr) \
363 : "r" (x), "i" (-EFAULT) \
364 : "cc")
365
366extern unsigned long __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
367extern unsigned long __arch_copy_to_user(void __user *to, const void *from, unsigned long n);
368extern unsigned long __arch_clear_user(void __user *addr, unsigned long n);
369extern unsigned long __arch_strncpy_from_user(char *to, const char __user *from, unsigned long count);
370extern unsigned long __arch_strnlen_user(const char __user *s, long n);
371
372static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
373{
374 if (access_ok(VERIFY_READ, from, n))
375 n = __arch_copy_from_user(to, from, n);
376 else /* security hole - plug it */
377 memzero(to, n);
378 return n;
379}
380
381static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
382{
383 return __arch_copy_from_user(to, from, n);
384}
385
386static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
387{
388 if (access_ok(VERIFY_WRITE, to, n))
389 n = __arch_copy_to_user(to, from, n);
390 return n;
391}
392
393static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
394{
395 return __arch_copy_to_user(to, from, n);
396}
397
398#define __copy_to_user_inatomic __copy_to_user
399#define __copy_from_user_inatomic __copy_from_user
400
401static inline unsigned long clear_user (void __user *to, unsigned long n)
402{
403 if (access_ok(VERIFY_WRITE, to, n))
404 n = __arch_clear_user(to, n);
405 return n;
406}
407
408static inline unsigned long __clear_user (void __user *to, unsigned long n)
409{
410 return __arch_clear_user(to, n);
411}
412
413static inline long strncpy_from_user (char *dst, const char __user *src, long count)
414{
415 long res = -EFAULT;
416 if (access_ok(VERIFY_READ, src, 1))
417 res = __arch_strncpy_from_user(dst, src, count);
418 return res;
419}
420
421static inline long __strncpy_from_user (char *dst, const char __user *src, long count)
422{
423 return __arch_strncpy_from_user(dst, src, count);
424}
425
426#define strlen_user(s) strnlen_user(s, ~0UL >> 1)
427
428static inline long strnlen_user(const char __user *s, long n)
429{
430 unsigned long res = 0;
431
432 if (__addr_ok(s))
433 res = __arch_strnlen_user(s, n);
434
435 return res;
436}
437
438#endif /* _ASMARM_UACCESS_H */
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