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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/system.h>
20#include <asm/unified.h>
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
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
52/*
53 * Note that this is actually 0x1,0000,0000
54 */
55#define KERNEL_DS 0x00000000
56#define get_ds() (KERNEL_DS)
57
58#ifdef CONFIG_MMU
59
60#define USER_DS TASK_SIZE
61#define get_fs() (current_thread_info()->addr_limit)
62
63static inline void set_fs(mm_segment_t fs)
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) ({ \
81 unsigned long flag, roksum; \
82 __chk_user_ptr(addr); \
83 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
84 : "=&r" (flag), "=&r" (roksum) \
85 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
86 : "cc"); \
87 flag; })
88
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.
99 */
100extern int __get_user_1(void *);
101extern int __get_user_2(void *);
102extern int __get_user_4(void *);
103
104#define __get_user_x(__r2,__p,__e,__s,__i...) \
105 __asm__ __volatile__ ( \
106 __asmeq("%0", "r0") __asmeq("%1", "r2") \
107 "bl __get_user_" #__s \
108 : "=&r" (__e), "=r" (__r2) \
109 : "0" (__p) \
110 : __i, "cc")
111
112#define get_user(x,p) \
113 ({ \
114 register const typeof(*(p)) __user *__p asm("r0") = (p);\
115 register unsigned long __r2 asm("r2"); \
116 register int __e asm("r0"); \
117 switch (sizeof(*(__p))) { \
118 case 1: \
119 __get_user_x(__r2, __p, __e, 1, "lr"); \
120 break; \
121 case 2: \
122 __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \
123 break; \
124 case 4: \
125 __get_user_x(__r2, __p, __e, 4, "lr"); \
126 break; \
127 default: __e = __get_user_bad(); break; \
128 } \
129 x = (typeof(*(p))) __r2; \
130 __e; \
131 })
132
133extern int __put_user_1(void *, unsigned int);
134extern int __put_user_2(void *, unsigned int);
135extern int __put_user_4(void *, unsigned int);
136extern int __put_user_8(void *, unsigned long long);
137
138#define __put_user_x(__r2,__p,__e,__s) \
139 __asm__ __volatile__ ( \
140 __asmeq("%0", "r0") __asmeq("%2", "r2") \
141 "bl __put_user_" #__s \
142 : "=&r" (__e) \
143 : "0" (__p), "r" (__r2) \
144 : "ip", "lr", "cc")
145
146#define put_user(x,p) \
147 ({ \
148 register const typeof(*(p)) __r2 asm("r2") = (x); \
149 register const typeof(*(p)) __user *__p asm("r0") = (p);\
150 register int __e asm("r0"); \
151 switch (sizeof(*(__p))) { \
152 case 1: \
153 __put_user_x(__r2, __p, __e, 1); \
154 break; \
155 case 2: \
156 __put_user_x(__r2, __p, __e, 2); \
157 break; \
158 case 4: \
159 __put_user_x(__r2, __p, __e, 4); \
160 break; \
161 case 8: \
162 __put_user_x(__r2, __p, __e, 8); \
163 break; \
164 default: __e = __put_user_bad(); break; \
165 } \
166 __e; \
167 })
168
169#else /* CONFIG_MMU */
170
171/*
172 * uClinux has only one addr space, so has simplified address limits.
173 */
174#define USER_DS KERNEL_DS
175
176#define segment_eq(a,b) (1)
177#define __addr_ok(addr) (1)
178#define __range_ok(addr,size) (0)
179#define get_fs() (KERNEL_DS)
180
181static inline void set_fs(mm_segment_t fs)
182{
183}
184
185#define get_user(x,p) __get_user(x,p)
186#define put_user(x,p) __put_user(x,p)
187
188#endif /* CONFIG_MMU */
189
190#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
191
192/*
193 * The "__xxx" versions of the user access functions do not verify the
194 * address space - it must have been done previously with a separate
195 * "access_ok()" call.
196 *
197 * The "xxx_error" versions set the third argument to EFAULT if an
198 * error occurs, and leave it unchanged on success. Note that these
199 * versions are void (ie, don't return a value as such).
200 */
201#define __get_user(x,ptr) \
202({ \
203 long __gu_err = 0; \
204 __get_user_err((x),(ptr),__gu_err); \
205 __gu_err; \
206})
207
208#define __get_user_error(x,ptr,err) \
209({ \
210 __get_user_err((x),(ptr),err); \
211 (void) 0; \
212})
213
214#define __get_user_err(x,ptr,err) \
215do { \
216 unsigned long __gu_addr = (unsigned long)(ptr); \
217 unsigned long __gu_val; \
218 __chk_user_ptr(ptr); \
219 switch (sizeof(*(ptr))) { \
220 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
221 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
222 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
223 default: (__gu_val) = __get_user_bad(); \
224 } \
225 (x) = (__typeof__(*(ptr)))__gu_val; \
226} while (0)
227
228#define __get_user_asm_byte(x,addr,err) \
229 __asm__ __volatile__( \
230 "1: " T(ldrb) " %1,[%2],#0\n" \
231 "2:\n" \
232 " .pushsection .fixup,\"ax\"\n" \
233 " .align 2\n" \
234 "3: mov %0, %3\n" \
235 " mov %1, #0\n" \
236 " b 2b\n" \
237 " .popsection\n" \
238 " .pushsection __ex_table,\"a\"\n" \
239 " .align 3\n" \
240 " .long 1b, 3b\n" \
241 " .popsection" \
242 : "+r" (err), "=&r" (x) \
243 : "r" (addr), "i" (-EFAULT) \
244 : "cc")
245
246#ifndef __ARMEB__
247#define __get_user_asm_half(x,__gu_addr,err) \
248({ \
249 unsigned long __b1, __b2; \
250 __get_user_asm_byte(__b1, __gu_addr, err); \
251 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
252 (x) = __b1 | (__b2 << 8); \
253})
254#else
255#define __get_user_asm_half(x,__gu_addr,err) \
256({ \
257 unsigned long __b1, __b2; \
258 __get_user_asm_byte(__b1, __gu_addr, err); \
259 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
260 (x) = (__b1 << 8) | __b2; \
261})
262#endif
263
264#define __get_user_asm_word(x,addr,err) \
265 __asm__ __volatile__( \
266 "1: " T(ldr) " %1,[%2],#0\n" \
267 "2:\n" \
268 " .pushsection .fixup,\"ax\"\n" \
269 " .align 2\n" \
270 "3: mov %0, %3\n" \
271 " mov %1, #0\n" \
272 " b 2b\n" \
273 " .popsection\n" \
274 " .pushsection __ex_table,\"a\"\n" \
275 " .align 3\n" \
276 " .long 1b, 3b\n" \
277 " .popsection" \
278 : "+r" (err), "=&r" (x) \
279 : "r" (addr), "i" (-EFAULT) \
280 : "cc")
281
282#define __put_user(x,ptr) \
283({ \
284 long __pu_err = 0; \
285 __put_user_err((x),(ptr),__pu_err); \
286 __pu_err; \
287})
288
289#define __put_user_error(x,ptr,err) \
290({ \
291 __put_user_err((x),(ptr),err); \
292 (void) 0; \
293})
294
295#define __put_user_err(x,ptr,err) \
296do { \
297 unsigned long __pu_addr = (unsigned long)(ptr); \
298 __typeof__(*(ptr)) __pu_val = (x); \
299 __chk_user_ptr(ptr); \
300 switch (sizeof(*(ptr))) { \
301 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
302 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
303 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
304 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
305 default: __put_user_bad(); \
306 } \
307} while (0)
308
309#define __put_user_asm_byte(x,__pu_addr,err) \
310 __asm__ __volatile__( \
311 "1: " T(strb) " %1,[%2],#0\n" \
312 "2:\n" \
313 " .pushsection .fixup,\"ax\"\n" \
314 " .align 2\n" \
315 "3: mov %0, %3\n" \
316 " b 2b\n" \
317 " .popsection\n" \
318 " .pushsection __ex_table,\"a\"\n" \
319 " .align 3\n" \
320 " .long 1b, 3b\n" \
321 " .popsection" \
322 : "+r" (err) \
323 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
324 : "cc")
325
326#ifndef __ARMEB__
327#define __put_user_asm_half(x,__pu_addr,err) \
328({ \
329 unsigned long __temp = (unsigned long)(x); \
330 __put_user_asm_byte(__temp, __pu_addr, err); \
331 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
332})
333#else
334#define __put_user_asm_half(x,__pu_addr,err) \
335({ \
336 unsigned long __temp = (unsigned long)(x); \
337 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
338 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
339})
340#endif
341
342#define __put_user_asm_word(x,__pu_addr,err) \
343 __asm__ __volatile__( \
344 "1: " T(str) " %1,[%2],#0\n" \
345 "2:\n" \
346 " .pushsection .fixup,\"ax\"\n" \
347 " .align 2\n" \
348 "3: mov %0, %3\n" \
349 " b 2b\n" \
350 " .popsection\n" \
351 " .pushsection __ex_table,\"a\"\n" \
352 " .align 3\n" \
353 " .long 1b, 3b\n" \
354 " .popsection" \
355 : "+r" (err) \
356 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
357 : "cc")
358
359#ifndef __ARMEB__
360#define __reg_oper0 "%R2"
361#define __reg_oper1 "%Q2"
362#else
363#define __reg_oper0 "%Q2"
364#define __reg_oper1 "%R2"
365#endif
366
367#define __put_user_asm_dword(x,__pu_addr,err) \
368 __asm__ __volatile__( \
369 ARM( "1: " T(str) " " __reg_oper1 ", [%1], #4\n" ) \
370 ARM( "2: " T(str) " " __reg_oper0 ", [%1]\n" ) \
371 THUMB( "1: " T(str) " " __reg_oper1 ", [%1]\n" ) \
372 THUMB( "2: " T(str) " " __reg_oper0 ", [%1, #4]\n" ) \
373 "3:\n" \
374 " .pushsection .fixup,\"ax\"\n" \
375 " .align 2\n" \
376 "4: mov %0, %3\n" \
377 " b 3b\n" \
378 " .popsection\n" \
379 " .pushsection __ex_table,\"a\"\n" \
380 " .align 3\n" \
381 " .long 1b, 4b\n" \
382 " .long 2b, 4b\n" \
383 " .popsection" \
384 : "+r" (err), "+r" (__pu_addr) \
385 : "r" (x), "i" (-EFAULT) \
386 : "cc")
387
388
389#ifdef CONFIG_MMU
390extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
391extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
392extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
393extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
394extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
395#else
396#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
397#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
398#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
399#endif
400
401extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count);
402extern unsigned long __must_check __strnlen_user(const char __user *s, long n);
403
404static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
405{
406 if (access_ok(VERIFY_READ, from, n))
407 n = __copy_from_user(to, from, n);
408 else /* security hole - plug it */
409 memset(to, 0, n);
410 return n;
411}
412
413static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
414{
415 if (access_ok(VERIFY_WRITE, to, n))
416 n = __copy_to_user(to, from, n);
417 return n;
418}
419
420#define __copy_to_user_inatomic __copy_to_user
421#define __copy_from_user_inatomic __copy_from_user
422
423static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
424{
425 if (access_ok(VERIFY_WRITE, to, n))
426 n = __clear_user(to, n);
427 return n;
428}
429
430static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count)
431{
432 long res = -EFAULT;
433 if (access_ok(VERIFY_READ, src, 1))
434 res = __strncpy_from_user(dst, src, count);
435 return res;
436}
437
438#define strlen_user(s) strnlen_user(s, ~0UL >> 1)
439
440static inline long __must_check strnlen_user(const char __user *s, long n)
441{
442 unsigned long res = 0;
443
444 if (__addr_ok(s))
445 res = __strnlen_user(s, n);
446
447 return res;
448}
449
450#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 <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 functions allow hooking accesses to userspace to increase
54 * system integrity by ensuring that the kernel can not inadvertantly
55 * perform such accesses (eg, via list poison values) which could then
56 * be exploited for priviledge escalation.
57 */
58static inline unsigned int uaccess_save_and_enable(void)
59{
60#ifdef CONFIG_CPU_SW_DOMAIN_PAN
61 unsigned int old_domain = get_domain();
62
63 /* Set the current domain access to permit user accesses */
64 set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
65 domain_val(DOMAIN_USER, DOMAIN_CLIENT));
66
67 return old_domain;
68#else
69 return 0;
70#endif
71}
72
73static inline void uaccess_restore(unsigned int flags)
74{
75#ifdef CONFIG_CPU_SW_DOMAIN_PAN
76 /* Restore the user access mask */
77 set_domain(flags);
78#endif
79}
80
81/*
82 * These two are intentionally not defined anywhere - if the kernel
83 * code generates any references to them, that's a bug.
84 */
85extern int __get_user_bad(void);
86extern int __put_user_bad(void);
87
88/*
89 * Note that this is actually 0x1,0000,0000
90 */
91#define KERNEL_DS 0x00000000
92#define get_ds() (KERNEL_DS)
93
94#ifdef CONFIG_MMU
95
96#define USER_DS TASK_SIZE
97#define get_fs() (current_thread_info()->addr_limit)
98
99static inline void set_fs(mm_segment_t fs)
100{
101 current_thread_info()->addr_limit = fs;
102 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
103}
104
105#define segment_eq(a, b) ((a) == (b))
106
107/* We use 33-bit arithmetic here... */
108#define __range_ok(addr, size) ({ \
109 unsigned long flag, roksum; \
110 __chk_user_ptr(addr); \
111 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
112 : "=&r" (flag), "=&r" (roksum) \
113 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
114 : "cc"); \
115 flag; })
116
117/*
118 * Single-value transfer routines. They automatically use the right
119 * size if we just have the right pointer type. Note that the functions
120 * which read from user space (*get_*) need to take care not to leak
121 * kernel data even if the calling code is buggy and fails to check
122 * the return value. This means zeroing out the destination variable
123 * or buffer on error. Normally this is done out of line by the
124 * fixup code, but there are a few places where it intrudes on the
125 * main code path. When we only write to user space, there is no
126 * problem.
127 */
128extern int __get_user_1(void *);
129extern int __get_user_2(void *);
130extern int __get_user_4(void *);
131extern int __get_user_32t_8(void *);
132extern int __get_user_8(void *);
133extern int __get_user_64t_1(void *);
134extern int __get_user_64t_2(void *);
135extern int __get_user_64t_4(void *);
136
137#define __GUP_CLOBBER_1 "lr", "cc"
138#ifdef CONFIG_CPU_USE_DOMAINS
139#define __GUP_CLOBBER_2 "ip", "lr", "cc"
140#else
141#define __GUP_CLOBBER_2 "lr", "cc"
142#endif
143#define __GUP_CLOBBER_4 "lr", "cc"
144#define __GUP_CLOBBER_32t_8 "lr", "cc"
145#define __GUP_CLOBBER_8 "lr", "cc"
146
147#define __get_user_x(__r2, __p, __e, __l, __s) \
148 __asm__ __volatile__ ( \
149 __asmeq("%0", "r0") __asmeq("%1", "r2") \
150 __asmeq("%3", "r1") \
151 "bl __get_user_" #__s \
152 : "=&r" (__e), "=r" (__r2) \
153 : "0" (__p), "r" (__l) \
154 : __GUP_CLOBBER_##__s)
155
156/* narrowing a double-word get into a single 32bit word register: */
157#ifdef __ARMEB__
158#define __get_user_x_32t(__r2, __p, __e, __l, __s) \
159 __get_user_x(__r2, __p, __e, __l, 32t_8)
160#else
161#define __get_user_x_32t __get_user_x
162#endif
163
164/*
165 * storing result into proper least significant word of 64bit target var,
166 * different only for big endian case where 64 bit __r2 lsw is r3:
167 */
168#ifdef __ARMEB__
169#define __get_user_x_64t(__r2, __p, __e, __l, __s) \
170 __asm__ __volatile__ ( \
171 __asmeq("%0", "r0") __asmeq("%1", "r2") \
172 __asmeq("%3", "r1") \
173 "bl __get_user_64t_" #__s \
174 : "=&r" (__e), "=r" (__r2) \
175 : "0" (__p), "r" (__l) \
176 : __GUP_CLOBBER_##__s)
177#else
178#define __get_user_x_64t __get_user_x
179#endif
180
181
182#define __get_user_check(x, p) \
183 ({ \
184 unsigned long __limit = current_thread_info()->addr_limit - 1; \
185 register const typeof(*(p)) __user *__p asm("r0") = (p);\
186 register typeof(x) __r2 asm("r2"); \
187 register unsigned long __l asm("r1") = __limit; \
188 register int __e asm("r0"); \
189 unsigned int __ua_flags = uaccess_save_and_enable(); \
190 switch (sizeof(*(__p))) { \
191 case 1: \
192 if (sizeof((x)) >= 8) \
193 __get_user_x_64t(__r2, __p, __e, __l, 1); \
194 else \
195 __get_user_x(__r2, __p, __e, __l, 1); \
196 break; \
197 case 2: \
198 if (sizeof((x)) >= 8) \
199 __get_user_x_64t(__r2, __p, __e, __l, 2); \
200 else \
201 __get_user_x(__r2, __p, __e, __l, 2); \
202 break; \
203 case 4: \
204 if (sizeof((x)) >= 8) \
205 __get_user_x_64t(__r2, __p, __e, __l, 4); \
206 else \
207 __get_user_x(__r2, __p, __e, __l, 4); \
208 break; \
209 case 8: \
210 if (sizeof((x)) < 8) \
211 __get_user_x_32t(__r2, __p, __e, __l, 4); \
212 else \
213 __get_user_x(__r2, __p, __e, __l, 8); \
214 break; \
215 default: __e = __get_user_bad(); break; \
216 } \
217 uaccess_restore(__ua_flags); \
218 x = (typeof(*(p))) __r2; \
219 __e; \
220 })
221
222#define get_user(x, p) \
223 ({ \
224 might_fault(); \
225 __get_user_check(x, p); \
226 })
227
228extern int __put_user_1(void *, unsigned int);
229extern int __put_user_2(void *, unsigned int);
230extern int __put_user_4(void *, unsigned int);
231extern int __put_user_8(void *, unsigned long long);
232
233#define __put_user_check(__pu_val, __ptr, __err, __s) \
234 ({ \
235 unsigned long __limit = current_thread_info()->addr_limit - 1; \
236 register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
237 register const void __user *__p asm("r0") = __ptr; \
238 register unsigned long __l asm("r1") = __limit; \
239 register int __e asm("r0"); \
240 __asm__ __volatile__ ( \
241 __asmeq("%0", "r0") __asmeq("%2", "r2") \
242 __asmeq("%3", "r1") \
243 "bl __put_user_" #__s \
244 : "=&r" (__e) \
245 : "0" (__p), "r" (__r2), "r" (__l) \
246 : "ip", "lr", "cc"); \
247 __err = __e; \
248 })
249
250#else /* CONFIG_MMU */
251
252/*
253 * uClinux has only one addr space, so has simplified address limits.
254 */
255#define USER_DS KERNEL_DS
256
257#define segment_eq(a, b) (1)
258#define __addr_ok(addr) ((void)(addr), 1)
259#define __range_ok(addr, size) ((void)(addr), 0)
260#define get_fs() (KERNEL_DS)
261
262static inline void set_fs(mm_segment_t fs)
263{
264}
265
266#define get_user(x, p) __get_user(x, p)
267#define __put_user_check __put_user_nocheck
268
269#endif /* CONFIG_MMU */
270
271#define access_ok(type, addr, size) (__range_ok(addr, size) == 0)
272
273#define user_addr_max() \
274 (segment_eq(get_fs(), KERNEL_DS) ? ~0UL : get_fs())
275
276/*
277 * The "__xxx" versions of the user access functions do not verify the
278 * address space - it must have been done previously with a separate
279 * "access_ok()" call.
280 *
281 * The "xxx_error" versions set the third argument to EFAULT if an
282 * error occurs, and leave it unchanged on success. Note that these
283 * versions are void (ie, don't return a value as such).
284 */
285#define __get_user(x, ptr) \
286({ \
287 long __gu_err = 0; \
288 __get_user_err((x), (ptr), __gu_err); \
289 __gu_err; \
290})
291
292#define __get_user_error(x, ptr, err) \
293({ \
294 __get_user_err((x), (ptr), err); \
295 (void) 0; \
296})
297
298#define __get_user_err(x, ptr, err) \
299do { \
300 unsigned long __gu_addr = (unsigned long)(ptr); \
301 unsigned long __gu_val; \
302 unsigned int __ua_flags; \
303 __chk_user_ptr(ptr); \
304 might_fault(); \
305 __ua_flags = uaccess_save_and_enable(); \
306 switch (sizeof(*(ptr))) { \
307 case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
308 case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
309 case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
310 default: (__gu_val) = __get_user_bad(); \
311 } \
312 uaccess_restore(__ua_flags); \
313 (x) = (__typeof__(*(ptr)))__gu_val; \
314} while (0)
315
316#define __get_user_asm(x, addr, err, instr) \
317 __asm__ __volatile__( \
318 "1: " TUSER(instr) " %1, [%2], #0\n" \
319 "2:\n" \
320 " .pushsection .text.fixup,\"ax\"\n" \
321 " .align 2\n" \
322 "3: mov %0, %3\n" \
323 " mov %1, #0\n" \
324 " b 2b\n" \
325 " .popsection\n" \
326 " .pushsection __ex_table,\"a\"\n" \
327 " .align 3\n" \
328 " .long 1b, 3b\n" \
329 " .popsection" \
330 : "+r" (err), "=&r" (x) \
331 : "r" (addr), "i" (-EFAULT) \
332 : "cc")
333
334#define __get_user_asm_byte(x, addr, err) \
335 __get_user_asm(x, addr, err, ldrb)
336
337#ifndef __ARMEB__
338#define __get_user_asm_half(x, __gu_addr, err) \
339({ \
340 unsigned long __b1, __b2; \
341 __get_user_asm_byte(__b1, __gu_addr, err); \
342 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
343 (x) = __b1 | (__b2 << 8); \
344})
345#else
346#define __get_user_asm_half(x, __gu_addr, err) \
347({ \
348 unsigned long __b1, __b2; \
349 __get_user_asm_byte(__b1, __gu_addr, err); \
350 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
351 (x) = (__b1 << 8) | __b2; \
352})
353#endif
354
355#define __get_user_asm_word(x, addr, err) \
356 __get_user_asm(x, addr, err, ldr)
357
358
359#define __put_user_switch(x, ptr, __err, __fn) \
360 do { \
361 const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
362 __typeof__(*(ptr)) __pu_val = (x); \
363 unsigned int __ua_flags; \
364 might_fault(); \
365 __ua_flags = uaccess_save_and_enable(); \
366 switch (sizeof(*(ptr))) { \
367 case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
368 case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
369 case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
370 case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
371 default: __err = __put_user_bad(); break; \
372 } \
373 uaccess_restore(__ua_flags); \
374 } while (0)
375
376#define put_user(x, ptr) \
377({ \
378 int __pu_err = 0; \
379 __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
380 __pu_err; \
381})
382
383#define __put_user(x, ptr) \
384({ \
385 long __pu_err = 0; \
386 __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
387 __pu_err; \
388})
389
390#define __put_user_error(x, ptr, err) \
391({ \
392 __put_user_switch((x), (ptr), (err), __put_user_nocheck); \
393 (void) 0; \
394})
395
396#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
397 do { \
398 unsigned long __pu_addr = (unsigned long)__pu_ptr; \
399 __put_user_nocheck_##__size(x, __pu_addr, __err); \
400 } while (0)
401
402#define __put_user_nocheck_1 __put_user_asm_byte
403#define __put_user_nocheck_2 __put_user_asm_half
404#define __put_user_nocheck_4 __put_user_asm_word
405#define __put_user_nocheck_8 __put_user_asm_dword
406
407#define __put_user_asm(x, __pu_addr, err, instr) \
408 __asm__ __volatile__( \
409 "1: " TUSER(instr) " %1, [%2], #0\n" \
410 "2:\n" \
411 " .pushsection .text.fixup,\"ax\"\n" \
412 " .align 2\n" \
413 "3: mov %0, %3\n" \
414 " b 2b\n" \
415 " .popsection\n" \
416 " .pushsection __ex_table,\"a\"\n" \
417 " .align 3\n" \
418 " .long 1b, 3b\n" \
419 " .popsection" \
420 : "+r" (err) \
421 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
422 : "cc")
423
424#define __put_user_asm_byte(x, __pu_addr, err) \
425 __put_user_asm(x, __pu_addr, err, strb)
426
427#ifndef __ARMEB__
428#define __put_user_asm_half(x, __pu_addr, err) \
429({ \
430 unsigned long __temp = (__force unsigned long)(x); \
431 __put_user_asm_byte(__temp, __pu_addr, err); \
432 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
433})
434#else
435#define __put_user_asm_half(x, __pu_addr, err) \
436({ \
437 unsigned long __temp = (__force unsigned long)(x); \
438 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
439 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
440})
441#endif
442
443#define __put_user_asm_word(x, __pu_addr, err) \
444 __put_user_asm(x, __pu_addr, err, str)
445
446#ifndef __ARMEB__
447#define __reg_oper0 "%R2"
448#define __reg_oper1 "%Q2"
449#else
450#define __reg_oper0 "%Q2"
451#define __reg_oper1 "%R2"
452#endif
453
454#define __put_user_asm_dword(x, __pu_addr, err) \
455 __asm__ __volatile__( \
456 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
457 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
458 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
459 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
460 "3:\n" \
461 " .pushsection .text.fixup,\"ax\"\n" \
462 " .align 2\n" \
463 "4: mov %0, %3\n" \
464 " b 3b\n" \
465 " .popsection\n" \
466 " .pushsection __ex_table,\"a\"\n" \
467 " .align 3\n" \
468 " .long 1b, 4b\n" \
469 " .long 2b, 4b\n" \
470 " .popsection" \
471 : "+r" (err), "+r" (__pu_addr) \
472 : "r" (x), "i" (-EFAULT) \
473 : "cc")
474
475
476#ifdef CONFIG_MMU
477extern unsigned long __must_check
478arm_copy_from_user(void *to, const void __user *from, unsigned long n);
479
480static inline unsigned long __must_check
481__arch_copy_from_user(void *to, const void __user *from, unsigned long n)
482{
483 unsigned int __ua_flags;
484
485 __ua_flags = uaccess_save_and_enable();
486 n = arm_copy_from_user(to, from, n);
487 uaccess_restore(__ua_flags);
488 return n;
489}
490
491extern unsigned long __must_check
492arm_copy_to_user(void __user *to, const void *from, unsigned long n);
493extern unsigned long __must_check
494__copy_to_user_std(void __user *to, const void *from, unsigned long n);
495
496static inline unsigned long __must_check
497__arch_copy_to_user(void __user *to, const void *from, unsigned long n)
498{
499#ifndef CONFIG_UACCESS_WITH_MEMCPY
500 unsigned int __ua_flags;
501 __ua_flags = uaccess_save_and_enable();
502 n = arm_copy_to_user(to, from, n);
503 uaccess_restore(__ua_flags);
504 return n;
505#else
506 return arm_copy_to_user(to, from, n);
507#endif
508}
509
510extern unsigned long __must_check
511arm_clear_user(void __user *addr, unsigned long n);
512extern unsigned long __must_check
513__clear_user_std(void __user *addr, unsigned long n);
514
515static inline unsigned long __must_check
516__clear_user(void __user *addr, unsigned long n)
517{
518 unsigned int __ua_flags = uaccess_save_and_enable();
519 n = arm_clear_user(addr, n);
520 uaccess_restore(__ua_flags);
521 return n;
522}
523
524#else
525#define __arch_copy_from_user(to, from, n) \
526 (memcpy(to, (void __force *)from, n), 0)
527#define __arch_copy_to_user(to, from, n) \
528 (memcpy((void __force *)to, from, n), 0)
529#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
530#endif
531
532static inline unsigned long __must_check
533__copy_from_user(void *to, const void __user *from, unsigned long n)
534{
535 check_object_size(to, n, false);
536 return __arch_copy_from_user(to, from, n);
537}
538
539static inline unsigned long __must_check
540copy_from_user(void *to, const void __user *from, unsigned long n)
541{
542 unsigned long res = n;
543
544 check_object_size(to, n, false);
545
546 if (likely(access_ok(VERIFY_READ, from, n)))
547 res = __arch_copy_from_user(to, from, n);
548 if (unlikely(res))
549 memset(to + (n - res), 0, res);
550 return res;
551}
552
553static inline unsigned long __must_check
554__copy_to_user(void __user *to, const void *from, unsigned long n)
555{
556 check_object_size(from, n, true);
557
558 return __arch_copy_to_user(to, from, n);
559}
560
561static inline unsigned long __must_check
562copy_to_user(void __user *to, const void *from, unsigned long n)
563{
564 check_object_size(from, n, true);
565
566 if (access_ok(VERIFY_WRITE, to, n))
567 n = __arch_copy_to_user(to, from, n);
568 return n;
569}
570
571#define __copy_to_user_inatomic __copy_to_user
572#define __copy_from_user_inatomic __copy_from_user
573
574static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
575{
576 if (access_ok(VERIFY_WRITE, to, n))
577 n = __clear_user(to, n);
578 return n;
579}
580
581/* These are from lib/ code, and use __get_user() and friends */
582extern long strncpy_from_user(char *dest, const char __user *src, long count);
583
584extern __must_check long strlen_user(const char __user *str);
585extern __must_check long strnlen_user(const char __user *str, long n);
586
587#endif /* _ASMARM_UACCESS_H */