1/* 2 * Copyright (C) 2004-2006 Atmel Corporation 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 __ASM_AVR32_UACCESS_H 9#define __ASM_AVR32_UACCESS_H 10 11#include <linux/errno.h> 12#include <linux/sched.h> 13 14#define VERIFY_READ 0 15#define VERIFY_WRITE 1 16 17typedef struct { 18 unsigned int is_user_space; 19} mm_segment_t; 20 21/* 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. 25 * 26 * For historical reasons (Data Segment Register?), these macros are misnamed. 27 */ 28#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 29#define segment_eq(a, b) ((a).is_user_space == (b).is_user_space) 30 31#define USER_ADDR_LIMIT 0x80000000 32 33#define KERNEL_DS MAKE_MM_SEG(0) 34#define USER_DS MAKE_MM_SEG(1) 35 36#define get_ds() (KERNEL_DS) 37 38static inline mm_segment_t get_fs(void) 39{ 40 return MAKE_MM_SEG(test_thread_flag(TIF_USERSPACE)); 41} 42 43static inline void set_fs(mm_segment_t s) 44{ 45 if (s.is_user_space) 46 set_thread_flag(TIF_USERSPACE); 47 else 48 clear_thread_flag(TIF_USERSPACE); 49} 50 51/* 52 * Test whether a block of memory is a valid user space address. 53 * Returns 0 if the range is valid, nonzero otherwise. 54 * 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)? 59 * 60 * If yes on the first check, access is granted. 61 * If no on any of the others, access is denied. 62 */ 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))) 68 69#define access_ok(type, addr, size) (likely(__range_ok(addr, size) == 0)) 70 71/* Generic arbitrary sized copy. Return the number of bytes NOT copied */ 72extern __kernel_size_t __copy_user(void *to, const void *from, 73 __kernel_size_t n); 74 75extern __kernel_size_t copy_to_user(void __user *to, const void *from, 76 __kernel_size_t n); 77extern __kernel_size_t copy_from_user(void *to, const void __user *from, 78 __kernel_size_t n); 79 80static inline __kernel_size_t __copy_to_user(void __user *to, const void *from, 81 __kernel_size_t n) 82{ 83 return __copy_user((void __force *)to, from, n); 84} 85static inline __kernel_size_t __copy_from_user(void *to, 86 const void __user *from, 87 __kernel_size_t n) 88{ 89 return __copy_user(to, (const void __force *)from, n); 90} 91 92#define __copy_to_user_inatomic __copy_to_user 93#define __copy_from_user_inatomic __copy_from_user 94 95/* 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. 99 * 100 * Context: User context only. This function may sleep if pagefaults are 101 * enabled. 102 * 103 * This macro copies a single simple value from kernel space to user 104 * space. It supports simple types like char and int, but not larger 105 * data types like structures or arrays. 106 * 107 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 108 * to the result of dereferencing @ptr. 109 * 110 * Returns zero on success, or -EFAULT on error. 111 */ 112#define put_user(x, ptr) \ 113 __put_user_check((x), (ptr), sizeof(*(ptr))) 114 115/* 116 * get_user: - Get a simple variable from user space. 117 * @x: Variable to store result. 118 * @ptr: Source address, in user space. 119 * 120 * Context: User context only. This function may sleep if pagefaults are 121 * enabled. 122 * 123 * This macro copies a single simple variable from user space to kernel 124 * space. It supports simple types like char and int, but not larger 125 * data types like structures or arrays. 126 * 127 * @ptr must have pointer-to-simple-variable type, and the result of 128 * dereferencing @ptr must be assignable to @x without a cast. 129 * 130 * Returns zero on success, or -EFAULT on error. 131 * On error, the variable @x is set to zero. 132 */ 133#define get_user(x, ptr) \ 134 __get_user_check((x), (ptr), sizeof(*(ptr))) 135 136/* 137 * __put_user: - Write a simple value into user space, with less checking. 138 * @x: Value to copy to user space. 139 * @ptr: Destination address, in user space. 140 * 141 * Context: User context only. This function may sleep if pagefaults are 142 * enabled. 143 * 144 * This macro copies a single simple value from kernel space to user 145 * space. It supports simple types like char and int, but not larger 146 * data types like structures or arrays. 147 * 148 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 149 * to the result of dereferencing @ptr. 150 * 151 * Caller must check the pointer with access_ok() before calling this 152 * function. 153 * 154 * Returns zero on success, or -EFAULT on error. 155 */ 156#define __put_user(x, ptr) \ 157 __put_user_nocheck((x), (ptr), sizeof(*(ptr))) 158 159/* 160 * __get_user: - Get a simple variable from user space, with less checking. 161 * @x: Variable to store result. 162 * @ptr: Source address, in user space. 163 * 164 * Context: User context only. This function may sleep if pagefaults are 165 * enabled. 166 * 167 * This macro copies a single simple variable from user space to kernel 168 * space. It supports simple types like char and int, but not larger 169 * data types like structures or arrays. 170 * 171 * @ptr must have pointer-to-simple-variable type, and the result of 172 * dereferencing @ptr must be assignable to @x without a cast. 173 * 174 * Caller must check the pointer with access_ok() before calling this 175 * function. 176 * 177 * Returns zero on success, or -EFAULT on error. 178 * On error, the variable @x is set to zero. 179 */ 180#define __get_user(x, ptr) \ 181 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 182 183extern int __get_user_bad(void); 184extern int __put_user_bad(void); 185 186#define __get_user_nocheck(x, ptr, size) \ 187({ \ 188 unsigned long __gu_val = 0; \ 189 int __gu_err = 0; \ 190 \ 191 switch (size) { \ 192 case 1: __get_user_asm("ub", __gu_val, ptr, __gu_err); break; \ 193 case 2: __get_user_asm("uh", __gu_val, ptr, __gu_err); break; \ 194 case 4: __get_user_asm("w", __gu_val, ptr, __gu_err); break; \ 195 default: __gu_err = __get_user_bad(); break; \ 196 } \ 197 \ 198 x = (__force typeof(*(ptr)))__gu_val; \ 199 __gu_err; \ 200}) 201 202#define __get_user_check(x, ptr, size) \ 203({ \ 204 unsigned long __gu_val = 0; \ 205 const typeof(*(ptr)) __user * __gu_addr = (ptr); \ 206 int __gu_err = 0; \ 207 \ 208 if (access_ok(VERIFY_READ, __gu_addr, size)) { \ 209 switch (size) { \ 210 case 1: \ 211 __get_user_asm("ub", __gu_val, __gu_addr, \ 212 __gu_err); \ 213 break; \ 214 case 2: \ 215 __get_user_asm("uh", __gu_val, __gu_addr, \ 216 __gu_err); \ 217 break; \ 218 case 4: \ 219 __get_user_asm("w", __gu_val, __gu_addr, \ 220 __gu_err); \ 221 break; \ 222 default: \ 223 __gu_err = __get_user_bad(); \ 224 break; \ 225 } \ 226 } else { \ 227 __gu_err = -EFAULT; \ 228 } \ 229 x = (__force typeof(*(ptr)))__gu_val; \ 230 __gu_err; \ 231}) 232 233#define __get_user_asm(suffix, __gu_val, ptr, __gu_err) \ 234 asm volatile( \ 235 "1: ld." suffix " %1, %3 \n" \ 236 "2: \n" \ 237 " .subsection 1 \n" \ 238 "3: mov %0, %4 \n" \ 239 " rjmp 2b \n" \ 240 " .subsection 0 \n" \ 241 " .section __ex_table, \"a\" \n" \ 242 " .long 1b, 3b \n" \ 243 " .previous \n" \ 244 : "=r"(__gu_err), "=r"(__gu_val) \ 245 : "0"(__gu_err), "m"(*(ptr)), "i"(-EFAULT)) 246 247#define __put_user_nocheck(x, ptr, size) \ 248({ \ 249 typeof(*(ptr)) __pu_val; \ 250 int __pu_err = 0; \ 251 \ 252 __pu_val = (x); \ 253 switch (size) { \ 254 case 1: __put_user_asm("b", ptr, __pu_val, __pu_err); break; \ 255 case 2: __put_user_asm("h", ptr, __pu_val, __pu_err); break; \ 256 case 4: __put_user_asm("w", ptr, __pu_val, __pu_err); break; \ 257 case 8: __put_user_asm("d", ptr, __pu_val, __pu_err); break; \ 258 default: __pu_err = __put_user_bad(); break; \ 259 } \ 260 __pu_err; \ 261}) 262 263#define __put_user_check(x, ptr, size) \ 264({ \ 265 typeof(*(ptr)) __pu_val; \ 266 typeof(*(ptr)) __user *__pu_addr = (ptr); \ 267 int __pu_err = 0; \ 268 \ 269 __pu_val = (x); \ 270 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ 271 switch (size) { \ 272 case 1: \ 273 __put_user_asm("b", __pu_addr, __pu_val, \ 274 __pu_err); \ 275 break; \ 276 case 2: \ 277 __put_user_asm("h", __pu_addr, __pu_val, \ 278 __pu_err); \ 279 break; \ 280 case 4: \ 281 __put_user_asm("w", __pu_addr, __pu_val, \ 282 __pu_err); \ 283 break; \ 284 case 8: \ 285 __put_user_asm("d", __pu_addr, __pu_val, \ 286 __pu_err); \ 287 break; \ 288 default: \ 289 __pu_err = __put_user_bad(); \ 290 break; \ 291 } \ 292 } else { \ 293 __pu_err = -EFAULT; \ 294 } \ 295 __pu_err; \ 296}) 297 298#define __put_user_asm(suffix, ptr, __pu_val, __gu_err) \ 299 asm volatile( \ 300 "1: st." suffix " %1, %3 \n" \ 301 "2: \n" \ 302 " .subsection 1 \n" \ 303 "3: mov %0, %4 \n" \ 304 " rjmp 2b \n" \ 305 " .subsection 0 \n" \ 306 " .section __ex_table, \"a\" \n" \ 307 " .long 1b, 3b \n" \ 308 " .previous \n" \ 309 : "=r"(__gu_err), "=m"(*(ptr)) \ 310 : "0"(__gu_err), "r"(__pu_val), "i"(-EFAULT)) 311 312extern __kernel_size_t clear_user(void __user *addr, __kernel_size_t size); 313extern __kernel_size_t __clear_user(void __user *addr, __kernel_size_t size); 314 315extern long strncpy_from_user(char *dst, const char __user *src, long count); 316extern long __strncpy_from_user(char *dst, const char __user *src, long count); 317 318extern long strnlen_user(const char __user *__s, long __n); 319extern long __strnlen_user(const char __user *__s, long __n); 320 321#define strlen_user(s) strnlen_user(s, ~0UL >> 1) 322 323struct exception_table_entry 324{ 325 unsigned long insn, fixup; 326}; 327 328#endif /* __ASM_AVR32_UACCESS_H */ 329