ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINS
[deliverable/linux.git] / arch / arm / include / asm / uaccess.h
CommitLineData
1da177e4 1/*
4baa9922 2 * arch/arm/include/asm/uaccess.h
1da177e4
LT
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 */
87c52578
RK
14#include <linux/string.h>
15#include <linux/thread_info.h>
1da177e4
LT
16#include <asm/errno.h>
17#include <asm/memory.h>
18#include <asm/domain.h>
8b592783 19#include <asm/unified.h>
9f97da78 20#include <asm/compiler.h>
1da177e4
LT
21
22#define VERIFY_READ 0
23#define VERIFY_WRITE 1
24
25/*
26 * The exception table consists of pairs of addresses: the first is the
27 * address of an instruction that is allowed to fault, and the second is
28 * the address at which the program should continue. No registers are
29 * modified, so it is entirely up to the continuation code to figure out
30 * what to do.
31 *
32 * All the routines below use bits of fixup code that are out of line
33 * with the main instruction path. This means when everything is well,
34 * we don't even have to jump over them. Further, they do not intrude
35 * on our cache or tlb entries.
36 */
37
38struct exception_table_entry
39{
40 unsigned long insn, fixup;
41};
42
43extern int fixup_exception(struct pt_regs *regs);
44
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45/*
46 * These two are intentionally not defined anywhere - if the kernel
47 * code generates any references to them, that's a bug.
48 */
49extern int __get_user_bad(void);
50extern int __put_user_bad(void);
51
1da177e4
LT
52/*
53 * Note that this is actually 0x1,0000,0000
54 */
55#define KERNEL_DS 0x00000000
1da177e4 56#define get_ds() (KERNEL_DS)
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57
58#ifdef CONFIG_MMU
59
60#define USER_DS TASK_SIZE
1da177e4
LT
61#define get_fs() (current_thread_info()->addr_limit)
62
9641c7cc 63static inline void set_fs(mm_segment_t fs)
1da177e4
LT
64{
65 current_thread_info()->addr_limit = fs;
66 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
67}
68
69#define segment_eq(a,b) ((a) == (b))
70
71#define __addr_ok(addr) ({ \
72 unsigned long flag; \
73 __asm__("cmp %2, %0; movlo %0, #0" \
74 : "=&r" (flag) \
75 : "0" (current_thread_info()->addr_limit), "r" (addr) \
76 : "cc"); \
77 (flag == 0); })
78
79/* We use 33-bit arithmetic here... */
80#define __range_ok(addr,size) ({ \
16cf5b39 81 unsigned long flag, roksum; \
1da177e4
LT
82 __chk_user_ptr(addr); \
83 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
16cf5b39 84 : "=&r" (flag), "=&r" (roksum) \
1da177e4
LT
85 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
86 : "cc"); \
87 flag; })
88
1da177e4
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89/*
90 * Single-value transfer routines. They automatically use the right
91 * size if we just have the right pointer type. Note that the functions
92 * which read from user space (*get_*) need to take care not to leak
93 * kernel data even if the calling code is buggy and fails to check
94 * the return value. This means zeroing out the destination variable
95 * or buffer on error. Normally this is done out of line by the
96 * fixup code, but there are a few places where it intrudes on the
97 * main code path. When we only write to user space, there is no
98 * problem.
1da177e4 99 */
1da177e4
LT
100extern int __get_user_1(void *);
101extern int __get_user_2(void *);
102extern int __get_user_4(void *);
1da177e4 103
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104#define __GUP_CLOBBER_1 "lr", "cc"
105#ifdef CONFIG_CPU_USE_DOMAINS
106#define __GUP_CLOBBER_2 "ip", "lr", "cc"
107#else
108#define __GUP_CLOBBER_2 "lr", "cc"
109#endif
110#define __GUP_CLOBBER_4 "lr", "cc"
111
112#define __get_user_x(__r2,__p,__e,__l,__s) \
1da177e4
LT
113 __asm__ __volatile__ ( \
114 __asmeq("%0", "r0") __asmeq("%1", "r2") \
8404663f 115 __asmeq("%3", "r1") \
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116 "bl __get_user_" #__s \
117 : "=&r" (__e), "=r" (__r2) \
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118 : "0" (__p), "r" (__l) \
119 : __GUP_CLOBBER_##__s)
1da177e4
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120
121#define get_user(x,p) \
122 ({ \
8404663f 123 unsigned long __limit = current_thread_info()->addr_limit - 1; \
c5a69d57 124 register const typeof(*(p)) __user *__p asm("r0") = (p);\
fc048b5b 125 register unsigned long __r2 asm("r2"); \
8404663f 126 register unsigned long __l asm("r1") = __limit; \
1da177e4
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127 register int __e asm("r0"); \
128 switch (sizeof(*(__p))) { \
129 case 1: \
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RK
130 __get_user_x(__r2, __p, __e, __l, 1); \
131 break; \
1da177e4 132 case 2: \
8404663f 133 __get_user_x(__r2, __p, __e, __l, 2); \
1da177e4
LT
134 break; \
135 case 4: \
8404663f 136 __get_user_x(__r2, __p, __e, __l, 4); \
1da177e4 137 break; \
1da177e4
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138 default: __e = __get_user_bad(); break; \
139 } \
d2c5b690 140 x = (typeof(*(p))) __r2; \
1da177e4
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141 __e; \
142 })
143
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144extern int __put_user_1(void *, unsigned int);
145extern int __put_user_2(void *, unsigned int);
146extern int __put_user_4(void *, unsigned int);
147extern int __put_user_8(void *, unsigned long long);
148
8404663f 149#define __put_user_x(__r2,__p,__e,__l,__s) \
9641c7cc
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150 __asm__ __volatile__ ( \
151 __asmeq("%0", "r0") __asmeq("%2", "r2") \
8404663f 152 __asmeq("%3", "r1") \
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153 "bl __put_user_" #__s \
154 : "=&r" (__e) \
8404663f 155 : "0" (__p), "r" (__r2), "r" (__l) \
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156 : "ip", "lr", "cc")
157
158#define put_user(x,p) \
159 ({ \
8404663f 160 unsigned long __limit = current_thread_info()->addr_limit - 1; \
c5a69d57
TK
161 register const typeof(*(p)) __r2 asm("r2") = (x); \
162 register const typeof(*(p)) __user *__p asm("r0") = (p);\
8404663f 163 register unsigned long __l asm("r1") = __limit; \
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RK
164 register int __e asm("r0"); \
165 switch (sizeof(*(__p))) { \
166 case 1: \
8404663f 167 __put_user_x(__r2, __p, __e, __l, 1); \
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168 break; \
169 case 2: \
8404663f 170 __put_user_x(__r2, __p, __e, __l, 2); \
9641c7cc
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171 break; \
172 case 4: \
8404663f 173 __put_user_x(__r2, __p, __e, __l, 4); \
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174 break; \
175 case 8: \
8404663f 176 __put_user_x(__r2, __p, __e, __l, 8); \
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177 break; \
178 default: __e = __put_user_bad(); break; \
179 } \
180 __e; \
181 })
182
183#else /* CONFIG_MMU */
184
185/*
186 * uClinux has only one addr space, so has simplified address limits.
187 */
188#define USER_DS KERNEL_DS
189
190#define segment_eq(a,b) (1)
191#define __addr_ok(addr) (1)
192#define __range_ok(addr,size) (0)
193#define get_fs() (KERNEL_DS)
194
195static inline void set_fs(mm_segment_t fs)
196{
197}
198
199#define get_user(x,p) __get_user(x,p)
200#define put_user(x,p) __put_user(x,p)
201
202#endif /* CONFIG_MMU */
203
204#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
205
8c56cc8b
WD
206#define user_addr_max() \
207 (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
208
9641c7cc
RK
209/*
210 * The "__xxx" versions of the user access functions do not verify the
211 * address space - it must have been done previously with a separate
212 * "access_ok()" call.
213 *
214 * The "xxx_error" versions set the third argument to EFAULT if an
215 * error occurs, and leave it unchanged on success. Note that these
216 * versions are void (ie, don't return a value as such).
217 */
1da177e4
LT
218#define __get_user(x,ptr) \
219({ \
220 long __gu_err = 0; \
221 __get_user_err((x),(ptr),__gu_err); \
222 __gu_err; \
223})
224
225#define __get_user_error(x,ptr,err) \
226({ \
227 __get_user_err((x),(ptr),err); \
228 (void) 0; \
229})
230
231#define __get_user_err(x,ptr,err) \
232do { \
233 unsigned long __gu_addr = (unsigned long)(ptr); \
234 unsigned long __gu_val; \
235 __chk_user_ptr(ptr); \
236 switch (sizeof(*(ptr))) { \
237 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
238 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
239 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
240 default: (__gu_val) = __get_user_bad(); \
241 } \
242 (x) = (__typeof__(*(ptr)))__gu_val; \
243} while (0)
244
245#define __get_user_asm_byte(x,addr,err) \
246 __asm__ __volatile__( \
4e7682d0 247 "1: " TUSER(ldrb) " %1,[%2],#0\n" \
1da177e4 248 "2:\n" \
4260415f 249 " .pushsection .fixup,\"ax\"\n" \
1da177e4
LT
250 " .align 2\n" \
251 "3: mov %0, %3\n" \
252 " mov %1, #0\n" \
253 " b 2b\n" \
4260415f
RK
254 " .popsection\n" \
255 " .pushsection __ex_table,\"a\"\n" \
1da177e4
LT
256 " .align 3\n" \
257 " .long 1b, 3b\n" \
4260415f 258 " .popsection" \
1da177e4
LT
259 : "+r" (err), "=&r" (x) \
260 : "r" (addr), "i" (-EFAULT) \
261 : "cc")
262
263#ifndef __ARMEB__
264#define __get_user_asm_half(x,__gu_addr,err) \
265({ \
266 unsigned long __b1, __b2; \
267 __get_user_asm_byte(__b1, __gu_addr, err); \
268 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
269 (x) = __b1 | (__b2 << 8); \
270})
271#else
272#define __get_user_asm_half(x,__gu_addr,err) \
273({ \
274 unsigned long __b1, __b2; \
275 __get_user_asm_byte(__b1, __gu_addr, err); \
276 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
277 (x) = (__b1 << 8) | __b2; \
278})
279#endif
280
281#define __get_user_asm_word(x,addr,err) \
282 __asm__ __volatile__( \
4e7682d0 283 "1: " TUSER(ldr) " %1,[%2],#0\n" \
1da177e4 284 "2:\n" \
4260415f 285 " .pushsection .fixup,\"ax\"\n" \
1da177e4
LT
286 " .align 2\n" \
287 "3: mov %0, %3\n" \
288 " mov %1, #0\n" \
289 " b 2b\n" \
4260415f
RK
290 " .popsection\n" \
291 " .pushsection __ex_table,\"a\"\n" \
1da177e4
LT
292 " .align 3\n" \
293 " .long 1b, 3b\n" \
4260415f 294 " .popsection" \
1da177e4
LT
295 : "+r" (err), "=&r" (x) \
296 : "r" (addr), "i" (-EFAULT) \
297 : "cc")
298
1da177e4
LT
299#define __put_user(x,ptr) \
300({ \
301 long __pu_err = 0; \
302 __put_user_err((x),(ptr),__pu_err); \
303 __pu_err; \
304})
305
306#define __put_user_error(x,ptr,err) \
307({ \
308 __put_user_err((x),(ptr),err); \
309 (void) 0; \
310})
311
312#define __put_user_err(x,ptr,err) \
313do { \
314 unsigned long __pu_addr = (unsigned long)(ptr); \
315 __typeof__(*(ptr)) __pu_val = (x); \
316 __chk_user_ptr(ptr); \
317 switch (sizeof(*(ptr))) { \
318 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
319 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
320 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
321 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
322 default: __put_user_bad(); \
323 } \
324} while (0)
325
326#define __put_user_asm_byte(x,__pu_addr,err) \
327 __asm__ __volatile__( \
4e7682d0 328 "1: " TUSER(strb) " %1,[%2],#0\n" \
1da177e4 329 "2:\n" \
4260415f 330 " .pushsection .fixup,\"ax\"\n" \
1da177e4
LT
331 " .align 2\n" \
332 "3: mov %0, %3\n" \
333 " b 2b\n" \
4260415f
RK
334 " .popsection\n" \
335 " .pushsection __ex_table,\"a\"\n" \
1da177e4
LT
336 " .align 3\n" \
337 " .long 1b, 3b\n" \
4260415f 338 " .popsection" \
1da177e4
LT
339 : "+r" (err) \
340 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
341 : "cc")
342
343#ifndef __ARMEB__
344#define __put_user_asm_half(x,__pu_addr,err) \
345({ \
346 unsigned long __temp = (unsigned long)(x); \
347 __put_user_asm_byte(__temp, __pu_addr, err); \
348 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
349})
350#else
351#define __put_user_asm_half(x,__pu_addr,err) \
352({ \
353 unsigned long __temp = (unsigned long)(x); \
354 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
355 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
356})
357#endif
358
359#define __put_user_asm_word(x,__pu_addr,err) \
360 __asm__ __volatile__( \
4e7682d0 361 "1: " TUSER(str) " %1,[%2],#0\n" \
1da177e4 362 "2:\n" \
4260415f 363 " .pushsection .fixup,\"ax\"\n" \
1da177e4
LT
364 " .align 2\n" \
365 "3: mov %0, %3\n" \
366 " b 2b\n" \
4260415f
RK
367 " .popsection\n" \
368 " .pushsection __ex_table,\"a\"\n" \
1da177e4
LT
369 " .align 3\n" \
370 " .long 1b, 3b\n" \
4260415f 371 " .popsection" \
1da177e4
LT
372 : "+r" (err) \
373 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
374 : "cc")
375
376#ifndef __ARMEB__
377#define __reg_oper0 "%R2"
378#define __reg_oper1 "%Q2"
379#else
380#define __reg_oper0 "%Q2"
381#define __reg_oper1 "%R2"
382#endif
383
384#define __put_user_asm_dword(x,__pu_addr,err) \
385 __asm__ __volatile__( \
4e7682d0
CM
386 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
387 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
388 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
389 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
1da177e4 390 "3:\n" \
4260415f 391 " .pushsection .fixup,\"ax\"\n" \
1da177e4
LT
392 " .align 2\n" \
393 "4: mov %0, %3\n" \
394 " b 3b\n" \
4260415f
RK
395 " .popsection\n" \
396 " .pushsection __ex_table,\"a\"\n" \
1da177e4
LT
397 " .align 3\n" \
398 " .long 1b, 4b\n" \
399 " .long 2b, 4b\n" \
4260415f 400 " .popsection" \
1da177e4
LT
401 : "+r" (err), "+r" (__pu_addr) \
402 : "r" (x), "i" (-EFAULT) \
403 : "cc")
404
02fcb974 405
9641c7cc 406#ifdef CONFIG_MMU
99573298
RK
407extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
408extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
a1f98849 409extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
99573298 410extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
a1f98849 411extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
9641c7cc
RK
412#else
413#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
414#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
415#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
416#endif
417
99573298 418static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
1da177e4
LT
419{
420 if (access_ok(VERIFY_READ, from, n))
02fcb974 421 n = __copy_from_user(to, from, n);
1da177e4 422 else /* security hole - plug it */
59f0cb0f 423 memset(to, 0, n);
1da177e4
LT
424 return n;
425}
426
99573298 427static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
1da177e4
LT
428{
429 if (access_ok(VERIFY_WRITE, to, n))
02fcb974 430 n = __copy_to_user(to, from, n);
1da177e4
LT
431 return n;
432}
433
1da177e4
LT
434#define __copy_to_user_inatomic __copy_to_user
435#define __copy_from_user_inatomic __copy_from_user
436
99573298 437static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
1da177e4
LT
438{
439 if (access_ok(VERIFY_WRITE, to, n))
02fcb974 440 n = __clear_user(to, n);
1da177e4
LT
441 return n;
442}
443
8c56cc8b 444extern long strncpy_from_user(char *dest, const char __user *src, long count);
1da177e4 445
8c56cc8b
WD
446extern __must_check long strlen_user(const char __user *str);
447extern __must_check long strnlen_user(const char __user *str, long n);
1da177e4
LT
448
449#endif /* _ASMARM_UACCESS_H */
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