2 * arch/arm/include/asm/uaccess.h
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.
8 #ifndef _ASMARM_UACCESS_H
9 #define _ASMARM_UACCESS_H
12 * User space memory access functions
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>
22 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
23 #include <asm-generic/uaccess-unaligned.h>
25 #define __get_user_unaligned __get_user
26 #define __put_user_unaligned __put_user
30 #define VERIFY_WRITE 1
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
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.
45 struct exception_table_entry
47 unsigned long insn, fixup;
50 extern int fixup_exception(struct pt_regs *regs);
53 * These two are intentionally not defined anywhere - if the kernel
54 * code generates any references to them, that's a bug.
56 extern int __get_user_bad(void);
57 extern int __put_user_bad(void);
60 * Note that this is actually 0x1,0000,0000
62 #define KERNEL_DS 0x00000000
63 #define get_ds() (KERNEL_DS)
67 #define USER_DS TASK_SIZE
68 #define get_fs() (current_thread_info()->addr_limit)
70 static inline void set_fs(mm_segment_t fs)
72 current_thread_info()->addr_limit = fs;
73 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
76 #define segment_eq(a,b) ((a) == (b))
78 #define __addr_ok(addr) ({ \
80 __asm__("cmp %2, %0; movlo %0, #0" \
82 : "0" (current_thread_info()->addr_limit), "r" (addr) \
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) \
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
107 extern int __get_user_1(void *);
108 extern int __get_user_2(void *);
109 extern int __get_user_4(void *);
111 #define __GUP_CLOBBER_1 "lr", "cc"
112 #ifdef CONFIG_CPU_USE_DOMAINS
113 #define __GUP_CLOBBER_2 "ip", "lr", "cc"
115 #define __GUP_CLOBBER_2 "lr", "cc"
117 #define __GUP_CLOBBER_4 "lr", "cc"
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)
128 #define __get_user_check(x,p) \
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))) { \
137 __get_user_x(__r2, __p, __e, __l, 1); \
140 __get_user_x(__r2, __p, __e, __l, 2); \
143 __get_user_x(__r2, __p, __e, __l, 4); \
145 default: __e = __get_user_bad(); break; \
147 x = (typeof(*(p))) __r2; \
151 #define get_user(x,p) \
154 __get_user_check(x,p); \
157 extern int __put_user_1(void *, unsigned int);
158 extern int __put_user_2(void *, unsigned int);
159 extern int __put_user_4(void *, unsigned int);
160 extern int __put_user_8(void *, unsigned long long);
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 \
168 : "0" (__p), "r" (__r2), "r" (__l) \
171 #define __put_user_check(x,p) \
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))) { \
181 __put_user_x(__r2, __p, __e, __l, 1); \
184 __put_user_x(__r2, __p, __e, __l, 2); \
187 __put_user_x(__r2, __p, __e, __l, 4); \
190 __put_user_x(__r2, __p, __e, __l, 8); \
192 default: __e = __put_user_bad(); break; \
197 #define put_user(x,p) \
200 __put_user_check(x,p); \
203 #else /* CONFIG_MMU */
206 * uClinux has only one addr space, so has simplified address limits.
208 #define USER_DS KERNEL_DS
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)
215 static inline void set_fs(mm_segment_t fs)
219 #define get_user(x,p) __get_user(x,p)
220 #define put_user(x,p) __put_user(x,p)
222 #endif /* CONFIG_MMU */
224 #define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
226 #define user_addr_max() \
227 (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
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.
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).
238 #define __get_user(x,ptr) \
241 __get_user_err((x),(ptr),__gu_err); \
245 #define __get_user_error(x,ptr,err) \
247 __get_user_err((x),(ptr),err); \
251 #define __get_user_err(x,ptr,err) \
253 unsigned long __gu_addr = (unsigned long)(ptr); \
254 unsigned long __gu_val; \
255 __chk_user_ptr(ptr); \
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(); \
263 (x) = (__typeof__(*(ptr)))__gu_val; \
266 #define __get_user_asm_byte(x,addr,err) \
267 __asm__ __volatile__( \
268 "1: " TUSER(ldrb) " %1,[%2],#0\n" \
270 " .pushsection .fixup,\"ax\"\n" \
276 " .pushsection __ex_table,\"a\"\n" \
280 : "+r" (err), "=&r" (x) \
281 : "r" (addr), "i" (-EFAULT) \
285 #define __get_user_asm_half(x,__gu_addr,err) \
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); \
293 #define __get_user_asm_half(x,__gu_addr,err) \
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; \
302 #define __get_user_asm_word(x,addr,err) \
303 __asm__ __volatile__( \
304 "1: " TUSER(ldr) " %1,[%2],#0\n" \
306 " .pushsection .fixup,\"ax\"\n" \
312 " .pushsection __ex_table,\"a\"\n" \
316 : "+r" (err), "=&r" (x) \
317 : "r" (addr), "i" (-EFAULT) \
320 #define __put_user(x,ptr) \
323 __put_user_err((x),(ptr),__pu_err); \
327 #define __put_user_error(x,ptr,err) \
329 __put_user_err((x),(ptr),err); \
333 #define __put_user_err(x,ptr,err) \
335 unsigned long __pu_addr = (unsigned long)(ptr); \
336 __typeof__(*(ptr)) __pu_val = (x); \
337 __chk_user_ptr(ptr); \
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(); \
348 #define __put_user_asm_byte(x,__pu_addr,err) \
349 __asm__ __volatile__( \
350 "1: " TUSER(strb) " %1,[%2],#0\n" \
352 " .pushsection .fixup,\"ax\"\n" \
357 " .pushsection __ex_table,\"a\"\n" \
362 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
366 #define __put_user_asm_half(x,__pu_addr,err) \
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); \
373 #define __put_user_asm_half(x,__pu_addr,err) \
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); \
381 #define __put_user_asm_word(x,__pu_addr,err) \
382 __asm__ __volatile__( \
383 "1: " TUSER(str) " %1,[%2],#0\n" \
385 " .pushsection .fixup,\"ax\"\n" \
390 " .pushsection __ex_table,\"a\"\n" \
395 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
399 #define __reg_oper0 "%R2"
400 #define __reg_oper1 "%Q2"
402 #define __reg_oper0 "%Q2"
403 #define __reg_oper1 "%R2"
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" ) \
413 " .pushsection .fixup,\"ax\"\n" \
418 " .pushsection __ex_table,\"a\"\n" \
423 : "+r" (err), "+r" (__pu_addr) \
424 : "r" (x), "i" (-EFAULT) \
429 extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
430 extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
431 extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
432 extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
433 extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
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)
440 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
442 if (access_ok(VERIFY_READ, from, n))
443 n = __copy_from_user(to, from, n);
444 else /* security hole - plug it */
449 static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
451 if (access_ok(VERIFY_WRITE, to, n))
452 n = __copy_to_user(to, from, n);
456 #define __copy_to_user_inatomic __copy_to_user
457 #define __copy_from_user_inatomic __copy_from_user
459 static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
461 if (access_ok(VERIFY_WRITE, to, n))
462 n = __clear_user(to, n);
466 extern long strncpy_from_user(char *dest, const char __user *src, long count);
468 extern __must_check long strlen_user(const char __user *str);
469 extern __must_check long strnlen_user(const char __user *str, long n);
471 #endif /* _ASMARM_UACCESS_H */