2 * Copyright (C) 2004-2006 Atmel Corporation
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 __ASM_AVR32_UACCESS_H
9 #define __ASM_AVR32_UACCESS_H
11 #include <linux/errno.h>
12 #include <linux/sched.h>
15 #define VERIFY_WRITE 1
18 unsigned int is_user_space;
22 * The fs value determines whether argument validity checking should be
23 * performed or not. If get_fs() == USER_DS, checking is performed, with
24 * get_fs() == KERNEL_DS, checking is bypassed.
26 * For historical reasons (Data Segment Register?), these macros are misnamed.
28 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
29 #define segment_eq(a,b) ((a).is_user_space == (b).is_user_space)
31 #define USER_ADDR_LIMIT 0x80000000
33 #define KERNEL_DS MAKE_MM_SEG(0)
34 #define USER_DS MAKE_MM_SEG(1)
36 #define get_ds() (KERNEL_DS)
38 static inline mm_segment_t get_fs(void)
40 return MAKE_MM_SEG(test_thread_flag(TIF_USERSPACE));
43 static inline void set_fs(mm_segment_t s)
46 set_thread_flag(TIF_USERSPACE);
48 clear_thread_flag(TIF_USERSPACE);
52 * Test whether a block of memory is a valid user space address.
53 * Returns 0 if the range is valid, nonzero otherwise.
55 * We do the following checks:
56 * 1. Is the access from kernel space?
57 * 2. Does (addr + size) set the carry bit?
58 * 3. Is (addr + size) a negative number (i.e. >= 0x80000000)?
60 * If yes on the first check, access is granted.
61 * If no on any of the others, access is denied.
63 #define __range_ok(addr, size) \
64 (test_thread_flag(TIF_USERSPACE) \
65 && (((unsigned long)(addr) >= 0x80000000) \
66 || ((unsigned long)(size) > 0x80000000) \
67 || (((unsigned long)(addr) + (unsigned long)(size)) > 0x80000000)))
69 #define access_ok(type, addr, size) (likely(__range_ok(addr, size) == 0))
71 /* Generic arbitrary sized copy. Return the number of bytes NOT copied */
72 extern __kernel_size_t __copy_user(void *to, const void *from,
75 extern __kernel_size_t copy_to_user(void __user *to, const void *from,
77 extern __kernel_size_t copy_from_user(void *to, const void __user *from,
80 static inline __kernel_size_t __copy_to_user(void __user *to, const void *from,
83 return __copy_user((void __force *)to, from, n);
85 static inline __kernel_size_t __copy_from_user(void *to,
86 const void __user *from,
89 return __copy_user(to, (const void __force *)from, n);
92 #define __copy_to_user_inatomic __copy_to_user
93 #define __copy_from_user_inatomic __copy_from_user
96 * put_user: - Write a simple value into user space.
97 * @x: Value to copy to user space.
98 * @ptr: Destination address, in user space.
100 * Context: User context only. This function may sleep.
102 * This macro copies a single simple value from kernel space to user
103 * space. It supports simple types like char and int, but not larger
104 * data types like structures or arrays.
106 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
107 * to the result of dereferencing @ptr.
109 * Returns zero on success, or -EFAULT on error.
111 #define put_user(x,ptr) \
112 __put_user_check((x),(ptr),sizeof(*(ptr)))
115 * get_user: - Get a simple variable from user space.
116 * @x: Variable to store result.
117 * @ptr: Source address, in user space.
119 * Context: User context only. This function may sleep.
121 * This macro copies a single simple variable from user space to kernel
122 * space. It supports simple types like char and int, but not larger
123 * data types like structures or arrays.
125 * @ptr must have pointer-to-simple-variable type, and the result of
126 * dereferencing @ptr must be assignable to @x without a cast.
128 * Returns zero on success, or -EFAULT on error.
129 * On error, the variable @x is set to zero.
131 #define get_user(x,ptr) \
132 __get_user_check((x),(ptr),sizeof(*(ptr)))
135 * __put_user: - Write a simple value into user space, with less checking.
136 * @x: Value to copy to user space.
137 * @ptr: Destination address, in user space.
139 * Context: User context only. This function may sleep.
141 * This macro copies a single simple value from kernel space to user
142 * space. It supports simple types like char and int, but not larger
143 * data types like structures or arrays.
145 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
146 * to the result of dereferencing @ptr.
148 * Caller must check the pointer with access_ok() before calling this
151 * Returns zero on success, or -EFAULT on error.
153 #define __put_user(x,ptr) \
154 __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
157 * __get_user: - Get a simple variable from user space, with less checking.
158 * @x: Variable to store result.
159 * @ptr: Source address, in user space.
161 * Context: User context only. This function may sleep.
163 * This macro copies a single simple variable from user space to kernel
164 * space. It supports simple types like char and int, but not larger
165 * data types like structures or arrays.
167 * @ptr must have pointer-to-simple-variable type, and the result of
168 * dereferencing @ptr must be assignable to @x without a cast.
170 * Caller must check the pointer with access_ok() before calling this
173 * Returns zero on success, or -EFAULT on error.
174 * On error, the variable @x is set to zero.
176 #define __get_user(x,ptr) \
177 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
179 extern int __get_user_bad(void);
180 extern int __put_user_bad(void);
182 #define __get_user_nocheck(x, ptr, size) \
184 unsigned long __gu_val = 0; \
188 case 1: __get_user_asm("ub", __gu_val, ptr, __gu_err); break; \
189 case 2: __get_user_asm("uh", __gu_val, ptr, __gu_err); break; \
190 case 4: __get_user_asm("w", __gu_val, ptr, __gu_err); break; \
191 default: __gu_err = __get_user_bad(); break; \
194 x = (typeof(*(ptr)))__gu_val; \
198 #define __get_user_check(x, ptr, size) \
200 unsigned long __gu_val = 0; \
201 const typeof(*(ptr)) __user * __gu_addr = (ptr); \
204 if (access_ok(VERIFY_READ, __gu_addr, size)) { \
207 __get_user_asm("ub", __gu_val, __gu_addr, \
211 __get_user_asm("uh", __gu_val, __gu_addr, \
215 __get_user_asm("w", __gu_val, __gu_addr, \
219 __gu_err = __get_user_bad(); \
223 __gu_err = -EFAULT; \
225 x = (typeof(*(ptr)))__gu_val; \
229 #define __get_user_asm(suffix, __gu_val, ptr, __gu_err) \
231 "1: ld." suffix " %1, %3 \n" \
233 " .section .fixup, \"ax\" \n" \
237 " .section __ex_table, \"a\" \n" \
240 : "=r"(__gu_err), "=r"(__gu_val) \
241 : "0"(__gu_err), "m"(*(ptr)), "i"(-EFAULT))
243 #define __put_user_nocheck(x, ptr, size) \
245 typeof(*(ptr)) __pu_val; \
250 case 1: __put_user_asm("b", ptr, __pu_val, __pu_err); break; \
251 case 2: __put_user_asm("h", ptr, __pu_val, __pu_err); break; \
252 case 4: __put_user_asm("w", ptr, __pu_val, __pu_err); break; \
253 case 8: __put_user_asm("d", ptr, __pu_val, __pu_err); break; \
254 default: __pu_err = __put_user_bad(); break; \
259 #define __put_user_check(x, ptr, size) \
261 typeof(*(ptr)) __pu_val; \
262 typeof(*(ptr)) __user *__pu_addr = (ptr); \
266 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \
269 __put_user_asm("b", __pu_addr, __pu_val, \
273 __put_user_asm("h", __pu_addr, __pu_val, \
277 __put_user_asm("w", __pu_addr, __pu_val, \
281 __put_user_asm("d", __pu_addr, __pu_val, \
285 __pu_err = __put_user_bad(); \
289 __pu_err = -EFAULT; \
294 #define __put_user_asm(suffix, ptr, __pu_val, __gu_err) \
296 "1: st." suffix " %1, %3 \n" \
298 " .section .fixup, \"ax\" \n" \
302 " .section __ex_table, \"a\" \n" \
305 : "=r"(__gu_err), "=m"(*(ptr)) \
306 : "0"(__gu_err), "r"(__pu_val), "i"(-EFAULT))
308 extern __kernel_size_t clear_user(void __user *addr, __kernel_size_t size);
309 extern __kernel_size_t __clear_user(void __user *addr, __kernel_size_t size);
311 extern long strncpy_from_user(char *dst, const char __user *src, long count);
312 extern long __strncpy_from_user(char *dst, const char __user *src, long count);
314 extern long strnlen_user(const char __user *__s, long __n);
315 extern long __strnlen_user(const char __user *__s, long __n);
317 #define strlen_user(s) strnlen_user(s, ~0UL >> 1)
319 struct exception_table_entry
321 unsigned long insn, fixup;
324 #endif /* __ASM_AVR32_UACCESS_H */