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. 101 * 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. 105 * 106 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 107 * to the result of dereferencing @ptr. 108 * 109 * Returns zero on success, or -EFAULT on error. 110 */ 111#define put_user(x,ptr) \ 112 __put_user_check((x),(ptr),sizeof(*(ptr))) 113 114/* 115 * get_user: - Get a simple variable from user space. 116 * @x: Variable to store result. 117 * @ptr: Source address, in user space. 118 * 119 * Context: User context only. This function may sleep. 120 * 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. 124 * 125 * @ptr must have pointer-to-simple-variable type, and the result of 126 * dereferencing @ptr must be assignable to @x without a cast. 127 * 128 * Returns zero on success, or -EFAULT on error. 129 * On error, the variable @x is set to zero. 130 */ 131#define get_user(x,ptr) \ 132 __get_user_check((x),(ptr),sizeof(*(ptr))) 133 134/* 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. 138 * 139 * Context: User context only. This function may sleep. 140 * 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. 144 * 145 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 146 * to the result of dereferencing @ptr. 147 * 148 * Caller must check the pointer with access_ok() before calling this 149 * function. 150 * 151 * Returns zero on success, or -EFAULT on error. 152 */ 153#define __put_user(x,ptr) \ 154 __put_user_nocheck((x),(ptr),sizeof(*(ptr))) 155 156/* 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. 160 * 161 * Context: User context only. This function may sleep. 162 * 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. 166 * 167 * @ptr must have pointer-to-simple-variable type, and the result of 168 * dereferencing @ptr must be assignable to @x without a cast. 169 * 170 * Caller must check the pointer with access_ok() before calling this 171 * function. 172 * 173 * Returns zero on success, or -EFAULT on error. 174 * On error, the variable @x is set to zero. 175 */ 176#define __get_user(x,ptr) \ 177 __get_user_nocheck((x),(ptr),sizeof(*(ptr))) 178 179extern int __get_user_bad(void); 180extern int __put_user_bad(void); 181 182#define __get_user_nocheck(x, ptr, size) \ 183({ \ 184 unsigned long __gu_val = 0; \ 185 int __gu_err = 0; \ 186 \ 187 switch (size) { \ 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; \ 192 } \ 193 \ 194 x = (typeof(*(ptr)))__gu_val; \ 195 __gu_err; \ 196}) 197 198#define __get_user_check(x, ptr, size) \ 199({ \ 200 unsigned long __gu_val = 0; \ 201 const typeof(*(ptr)) __user * __gu_addr = (ptr); \ 202 int __gu_err = 0; \ 203 \ 204 if (access_ok(VERIFY_READ, __gu_addr, size)) { \ 205 switch (size) { \ 206 case 1: \ 207 __get_user_asm("ub", __gu_val, __gu_addr, \ 208 __gu_err); \ 209 break; \ 210 case 2: \ 211 __get_user_asm("uh", __gu_val, __gu_addr, \ 212 __gu_err); \ 213 break; \ 214 case 4: \ 215 __get_user_asm("w", __gu_val, __gu_addr, \ 216 __gu_err); \ 217 break; \ 218 default: \ 219 __gu_err = __get_user_bad(); \ 220 break; \ 221 } \ 222 } else { \ 223 __gu_err = -EFAULT; \ 224 } \ 225 x = (typeof(*(ptr)))__gu_val; \ 226 __gu_err; \ 227}) 228 229#define __get_user_asm(suffix, __gu_val, ptr, __gu_err) \ 230 asm volatile( \ 231 "1: ld." suffix " %1, %3 \n" \ 232 "2: \n" \ 233 " .section .fixup, \"ax\" \n" \ 234 "3: mov %0, %4 \n" \ 235 " rjmp 2b \n" \ 236 " .previous \n" \ 237 " .section __ex_table, \"a\" \n" \ 238 " .long 1b, 3b \n" \ 239 " .previous \n" \ 240 : "=r"(__gu_err), "=r"(__gu_val) \ 241 : "0"(__gu_err), "m"(*(ptr)), "i"(-EFAULT)) 242 243#define __put_user_nocheck(x, ptr, size) \ 244({ \ 245 typeof(*(ptr)) __pu_val; \ 246 int __pu_err = 0; \ 247 \ 248 __pu_val = (x); \ 249 switch (size) { \ 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; \ 255 } \ 256 __pu_err; \ 257}) 258 259#define __put_user_check(x, ptr, size) \ 260({ \ 261 typeof(*(ptr)) __pu_val; \ 262 typeof(*(ptr)) __user *__pu_addr = (ptr); \ 263 int __pu_err = 0; \ 264 \ 265 __pu_val = (x); \ 266 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ 267 switch (size) { \ 268 case 1: \ 269 __put_user_asm("b", __pu_addr, __pu_val, \ 270 __pu_err); \ 271 break; \ 272 case 2: \ 273 __put_user_asm("h", __pu_addr, __pu_val, \ 274 __pu_err); \ 275 break; \ 276 case 4: \ 277 __put_user_asm("w", __pu_addr, __pu_val, \ 278 __pu_err); \ 279 break; \ 280 case 8: \ 281 __put_user_asm("d", __pu_addr, __pu_val, \ 282 __pu_err); \ 283 break; \ 284 default: \ 285 __pu_err = __put_user_bad(); \ 286 break; \ 287 } \ 288 } else { \ 289 __pu_err = -EFAULT; \ 290 } \ 291 __pu_err; \ 292}) 293 294#define __put_user_asm(suffix, ptr, __pu_val, __gu_err) \ 295 asm volatile( \ 296 "1: st." suffix " %1, %3 \n" \ 297 "2: \n" \ 298 " .section .fixup, \"ax\" \n" \ 299 "3: mov %0, %4 \n" \ 300 " rjmp 2b \n" \ 301 " .previous \n" \ 302 " .section __ex_table, \"a\" \n" \ 303 " .long 1b, 3b \n" \ 304 " .previous \n" \ 305 : "=r"(__gu_err), "=m"(*(ptr)) \ 306 : "0"(__gu_err), "r"(__pu_val), "i"(-EFAULT)) 307 308extern __kernel_size_t clear_user(void __user *addr, __kernel_size_t size); 309extern __kernel_size_t __clear_user(void __user *addr, __kernel_size_t size); 310 311extern long strncpy_from_user(char *dst, const char __user *src, long count); 312extern long __strncpy_from_user(char *dst, const char __user *src, long count); 313 314extern long strnlen_user(const char __user *__s, long __n); 315extern long __strnlen_user(const char __user *__s, long __n); 316 317#define strlen_user(s) strnlen_user(s, ~0UL >> 1) 318 319struct exception_table_entry 320{ 321 unsigned long insn, fixup; 322}; 323 324#endif /* __ASM_AVR32_UACCESS_H */ 325