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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 <linux/thread_info.h>
16#include <asm/errno.h>
17#include <asm/memory.h>
18#include <asm/domain.h>
19#include <asm/unified.h>
20#include <asm/compiler.h>
21
22#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
23#include <asm-generic/uaccess-unaligned.h>
24#else
25#define __get_user_unaligned __get_user
26#define __put_user_unaligned __put_user
27#endif
28
29#define VERIFY_READ 0
30#define VERIFY_WRITE 1
31
32/*
33 * The exception table consists of pairs of addresses: the first is the
34 * address of an instruction that is allowed to fault, and the second is
35 * the address at which the program should continue. No registers are
36 * modified, so it is entirely up to the continuation code to figure out
37 * what to do.
38 *
39 * All the routines below use bits of fixup code that are out of line
40 * with the main instruction path. This means when everything is well,
41 * we don't even have to jump over them. Further, they do not intrude
42 * on our cache or tlb entries.
43 */
44
45struct exception_table_entry
46{
47 unsigned long insn, fixup;
48};
49
50extern int fixup_exception(struct pt_regs *regs);
51
52/*
53 * These two are intentionally not defined anywhere - if the kernel
54 * code generates any references to them, that's a bug.
55 */
56extern int __get_user_bad(void);
57extern int __put_user_bad(void);
58
59/*
60 * Note that this is actually 0x1,0000,0000
61 */
62#define KERNEL_DS 0x00000000
63#define get_ds() (KERNEL_DS)
64
65#ifdef CONFIG_MMU
66
67#define USER_DS TASK_SIZE
68#define get_fs() (current_thread_info()->addr_limit)
69
70static inline void set_fs(mm_segment_t fs)
71{
72 current_thread_info()->addr_limit = fs;
73 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
74}
75
76#define segment_eq(a,b) ((a) == (b))
77
78#define __addr_ok(addr) ({ \
79 unsigned long flag; \
80 __asm__("cmp %2, %0; movlo %0, #0" \
81 : "=&r" (flag) \
82 : "0" (current_thread_info()->addr_limit), "r" (addr) \
83 : "cc"); \
84 (flag == 0); })
85
86/* We use 33-bit arithmetic here... */
87#define __range_ok(addr,size) ({ \
88 unsigned long flag, roksum; \
89 __chk_user_ptr(addr); \
90 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
91 : "=&r" (flag), "=&r" (roksum) \
92 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
93 : "cc"); \
94 flag; })
95
96/*
97 * Single-value transfer routines. They automatically use the right
98 * size if we just have the right pointer type. Note that the functions
99 * which read from user space (*get_*) need to take care not to leak
100 * kernel data even if the calling code is buggy and fails to check
101 * the return value. This means zeroing out the destination variable
102 * or buffer on error. Normally this is done out of line by the
103 * fixup code, but there are a few places where it intrudes on the
104 * main code path. When we only write to user space, there is no
105 * problem.
106 */
107extern int __get_user_1(void *);
108extern int __get_user_2(void *);
109extern int __get_user_4(void *);
110
111#define __GUP_CLOBBER_1 "lr", "cc"
112#ifdef CONFIG_CPU_USE_DOMAINS
113#define __GUP_CLOBBER_2 "ip", "lr", "cc"
114#else
115#define __GUP_CLOBBER_2 "lr", "cc"
116#endif
117#define __GUP_CLOBBER_4 "lr", "cc"
118
119#define __get_user_x(__r2,__p,__e,__l,__s) \
120 __asm__ __volatile__ ( \
121 __asmeq("%0", "r0") __asmeq("%1", "r2") \
122 __asmeq("%3", "r1") \
123 "bl __get_user_" #__s \
124 : "=&r" (__e), "=r" (__r2) \
125 : "0" (__p), "r" (__l) \
126 : __GUP_CLOBBER_##__s)
127
128#define __get_user_check(x,p) \
129 ({ \
130 unsigned long __limit = current_thread_info()->addr_limit - 1; \
131 register const typeof(*(p)) __user *__p asm("r0") = (p);\
132 register unsigned long __r2 asm("r2"); \
133 register unsigned long __l asm("r1") = __limit; \
134 register int __e asm("r0"); \
135 switch (sizeof(*(__p))) { \
136 case 1: \
137 __get_user_x(__r2, __p, __e, __l, 1); \
138 break; \
139 case 2: \
140 __get_user_x(__r2, __p, __e, __l, 2); \
141 break; \
142 case 4: \
143 __get_user_x(__r2, __p, __e, __l, 4); \
144 break; \
145 default: __e = __get_user_bad(); break; \
146 } \
147 x = (typeof(*(p))) __r2; \
148 __e; \
149 })
150
151#define get_user(x,p) \
152 ({ \
153 might_fault(); \
154 __get_user_check(x,p); \
155 })
156
157extern int __put_user_1(void *, unsigned int);
158extern int __put_user_2(void *, unsigned int);
159extern int __put_user_4(void *, unsigned int);
160extern int __put_user_8(void *, unsigned long long);
161
162#define __put_user_x(__r2,__p,__e,__l,__s) \
163 __asm__ __volatile__ ( \
164 __asmeq("%0", "r0") __asmeq("%2", "r2") \
165 __asmeq("%3", "r1") \
166 "bl __put_user_" #__s \
167 : "=&r" (__e) \
168 : "0" (__p), "r" (__r2), "r" (__l) \
169 : "ip", "lr", "cc")
170
171#define __put_user_check(x,p) \
172 ({ \
173 unsigned long __limit = current_thread_info()->addr_limit - 1; \
174 const typeof(*(p)) __user *__tmp_p = (p); \
175 register const typeof(*(p)) __r2 asm("r2") = (x); \
176 register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \
177 register unsigned long __l asm("r1") = __limit; \
178 register int __e asm("r0"); \
179 switch (sizeof(*(__p))) { \
180 case 1: \
181 __put_user_x(__r2, __p, __e, __l, 1); \
182 break; \
183 case 2: \
184 __put_user_x(__r2, __p, __e, __l, 2); \
185 break; \
186 case 4: \
187 __put_user_x(__r2, __p, __e, __l, 4); \
188 break; \
189 case 8: \
190 __put_user_x(__r2, __p, __e, __l, 8); \
191 break; \
192 default: __e = __put_user_bad(); break; \
193 } \
194 __e; \
195 })
196
197#define put_user(x,p) \
198 ({ \
199 might_fault(); \
200 __put_user_check(x,p); \
201 })
202
203#else /* CONFIG_MMU */
204
205/*
206 * uClinux has only one addr space, so has simplified address limits.
207 */
208#define USER_DS KERNEL_DS
209
210#define segment_eq(a,b) (1)
211#define __addr_ok(addr) ((void)(addr),1)
212#define __range_ok(addr,size) ((void)(addr),0)
213#define get_fs() (KERNEL_DS)
214
215static inline void set_fs(mm_segment_t fs)
216{
217}
218
219#define get_user(x,p) __get_user(x,p)
220#define put_user(x,p) __put_user(x,p)
221
222#endif /* CONFIG_MMU */
223
224#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
225
226#define user_addr_max() \
227 (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
228
229/*
230 * The "__xxx" versions of the user access functions do not verify the
231 * address space - it must have been done previously with a separate
232 * "access_ok()" call.
233 *
234 * The "xxx_error" versions set the third argument to EFAULT if an
235 * error occurs, and leave it unchanged on success. Note that these
236 * versions are void (ie, don't return a value as such).
237 */
238#define __get_user(x,ptr) \
239({ \
240 long __gu_err = 0; \
241 __get_user_err((x),(ptr),__gu_err); \
242 __gu_err; \
243})
244
245#define __get_user_error(x,ptr,err) \
246({ \
247 __get_user_err((x),(ptr),err); \
248 (void) 0; \
249})
250
251#define __get_user_err(x,ptr,err) \
252do { \
253 unsigned long __gu_addr = (unsigned long)(ptr); \
254 unsigned long __gu_val; \
255 __chk_user_ptr(ptr); \
256 might_fault(); \
257 switch (sizeof(*(ptr))) { \
258 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
259 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
260 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
261 default: (__gu_val) = __get_user_bad(); \
262 } \
263 (x) = (__typeof__(*(ptr)))__gu_val; \
264} while (0)
265
266#define __get_user_asm_byte(x,addr,err) \
267 __asm__ __volatile__( \
268 "1: " TUSER(ldrb) " %1,[%2],#0\n" \
269 "2:\n" \
270 " .pushsection .fixup,\"ax\"\n" \
271 " .align 2\n" \
272 "3: mov %0, %3\n" \
273 " mov %1, #0\n" \
274 " b 2b\n" \
275 " .popsection\n" \
276 " .pushsection __ex_table,\"a\"\n" \
277 " .align 3\n" \
278 " .long 1b, 3b\n" \
279 " .popsection" \
280 : "+r" (err), "=&r" (x) \
281 : "r" (addr), "i" (-EFAULT) \
282 : "cc")
283
284#ifndef __ARMEB__
285#define __get_user_asm_half(x,__gu_addr,err) \
286({ \
287 unsigned long __b1, __b2; \
288 __get_user_asm_byte(__b1, __gu_addr, err); \
289 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
290 (x) = __b1 | (__b2 << 8); \
291})
292#else
293#define __get_user_asm_half(x,__gu_addr,err) \
294({ \
295 unsigned long __b1, __b2; \
296 __get_user_asm_byte(__b1, __gu_addr, err); \
297 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
298 (x) = (__b1 << 8) | __b2; \
299})
300#endif
301
302#define __get_user_asm_word(x,addr,err) \
303 __asm__ __volatile__( \
304 "1: " TUSER(ldr) " %1,[%2],#0\n" \
305 "2:\n" \
306 " .pushsection .fixup,\"ax\"\n" \
307 " .align 2\n" \
308 "3: mov %0, %3\n" \
309 " mov %1, #0\n" \
310 " b 2b\n" \
311 " .popsection\n" \
312 " .pushsection __ex_table,\"a\"\n" \
313 " .align 3\n" \
314 " .long 1b, 3b\n" \
315 " .popsection" \
316 : "+r" (err), "=&r" (x) \
317 : "r" (addr), "i" (-EFAULT) \
318 : "cc")
319
320#define __put_user(x,ptr) \
321({ \
322 long __pu_err = 0; \
323 __put_user_err((x),(ptr),__pu_err); \
324 __pu_err; \
325})
326
327#define __put_user_error(x,ptr,err) \
328({ \
329 __put_user_err((x),(ptr),err); \
330 (void) 0; \
331})
332
333#define __put_user_err(x,ptr,err) \
334do { \
335 unsigned long __pu_addr = (unsigned long)(ptr); \
336 __typeof__(*(ptr)) __pu_val = (x); \
337 __chk_user_ptr(ptr); \
338 might_fault(); \
339 switch (sizeof(*(ptr))) { \
340 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
341 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
342 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
343 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
344 default: __put_user_bad(); \
345 } \
346} while (0)
347
348#define __put_user_asm_byte(x,__pu_addr,err) \
349 __asm__ __volatile__( \
350 "1: " TUSER(strb) " %1,[%2],#0\n" \
351 "2:\n" \
352 " .pushsection .fixup,\"ax\"\n" \
353 " .align 2\n" \
354 "3: mov %0, %3\n" \
355 " b 2b\n" \
356 " .popsection\n" \
357 " .pushsection __ex_table,\"a\"\n" \
358 " .align 3\n" \
359 " .long 1b, 3b\n" \
360 " .popsection" \
361 : "+r" (err) \
362 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
363 : "cc")
364
365#ifndef __ARMEB__
366#define __put_user_asm_half(x,__pu_addr,err) \
367({ \
368 unsigned long __temp = (unsigned long)(x); \
369 __put_user_asm_byte(__temp, __pu_addr, err); \
370 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
371})
372#else
373#define __put_user_asm_half(x,__pu_addr,err) \
374({ \
375 unsigned long __temp = (unsigned long)(x); \
376 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
377 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
378})
379#endif
380
381#define __put_user_asm_word(x,__pu_addr,err) \
382 __asm__ __volatile__( \
383 "1: " TUSER(str) " %1,[%2],#0\n" \
384 "2:\n" \
385 " .pushsection .fixup,\"ax\"\n" \
386 " .align 2\n" \
387 "3: mov %0, %3\n" \
388 " b 2b\n" \
389 " .popsection\n" \
390 " .pushsection __ex_table,\"a\"\n" \
391 " .align 3\n" \
392 " .long 1b, 3b\n" \
393 " .popsection" \
394 : "+r" (err) \
395 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
396 : "cc")
397
398#ifndef __ARMEB__
399#define __reg_oper0 "%R2"
400#define __reg_oper1 "%Q2"
401#else
402#define __reg_oper0 "%Q2"
403#define __reg_oper1 "%R2"
404#endif
405
406#define __put_user_asm_dword(x,__pu_addr,err) \
407 __asm__ __volatile__( \
408 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
409 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
410 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
411 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
412 "3:\n" \
413 " .pushsection .fixup,\"ax\"\n" \
414 " .align 2\n" \
415 "4: mov %0, %3\n" \
416 " b 3b\n" \
417 " .popsection\n" \
418 " .pushsection __ex_table,\"a\"\n" \
419 " .align 3\n" \
420 " .long 1b, 4b\n" \
421 " .long 2b, 4b\n" \
422 " .popsection" \
423 : "+r" (err), "+r" (__pu_addr) \
424 : "r" (x), "i" (-EFAULT) \
425 : "cc")
426
427
428#ifdef CONFIG_MMU
429extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
430extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
431extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
432extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
433extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
434#else
435#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
436#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
437#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
438#endif
439
440static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
441{
442 if (access_ok(VERIFY_READ, from, n))
443 n = __copy_from_user(to, from, n);
444 else /* security hole - plug it */
445 memset(to, 0, n);
446 return n;
447}
448
449static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
450{
451 if (access_ok(VERIFY_WRITE, to, n))
452 n = __copy_to_user(to, from, n);
453 return n;
454}
455
456#define __copy_to_user_inatomic __copy_to_user
457#define __copy_from_user_inatomic __copy_from_user
458
459static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
460{
461 if (access_ok(VERIFY_WRITE, to, n))
462 n = __clear_user(to, n);
463 return n;
464}
465
466extern long strncpy_from_user(char *dest, const char __user *src, long count);
467
468extern __must_check long strlen_user(const char __user *str);
469extern __must_check long strnlen_user(const char __user *str, long n);
470
471#endif /* _ASMARM_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 */
28static 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
43static 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 */
55extern int __get_user_bad(void);
56extern 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
69static 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 */
98extern int __get_user_1(void *);
99extern int __get_user_2(void *);
100extern int __get_user_4(void *);
101extern int __get_user_32t_8(void *);
102extern int __get_user_8(void *);
103extern int __get_user_64t_1(void *);
104extern int __get_user_64t_2(void *);
105extern 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
198extern int __put_user_1(void *, unsigned int);
199extern int __put_user_2(void *, unsigned int);
200extern int __put_user_4(void *, unsigned int);
201extern 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
232static 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) \
269do { \
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
447extern unsigned long __must_check
448arm_copy_from_user(void *to, const void __user *from, unsigned long n);
449
450static inline unsigned long __must_check
451raw_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
461extern unsigned long __must_check
462arm_copy_to_user(void __user *to, const void *from, unsigned long n);
463extern unsigned long __must_check
464__copy_to_user_std(void __user *to, const void *from, unsigned long n);
465
466static inline unsigned long __must_check
467raw_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
480extern unsigned long __must_check
481arm_clear_user(void __user *addr, unsigned long n);
482extern unsigned long __must_check
483__clear_user_std(void __user *addr, unsigned long n);
484
485static 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
495static inline unsigned long
496raw_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}
501static inline unsigned long
502raw_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
512static 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 */
520extern long strncpy_from_user(char *dest, const char __user *src, long count);
521
522extern __must_check long strnlen_user(const char __user *str, long n);
523
524#endif /* _ASMARM_UACCESS_H */