1 /* 2 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> 3 * Copyright (C) 2008-2009 PetaLogix 4 * Copyright (C) 2006 Atmark Techno, Inc. 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10 11 #ifndef _ASM_MICROBLAZE_UACCESS_H 12 #define _ASM_MICROBLAZE_UACCESS_H 13 14 #ifdef __KERNEL__ 15 #ifndef __ASSEMBLY__ 16 17 #include <linux/kernel.h> 18 #include <linux/errno.h> 19 #include <linux/sched.h> /* RLIMIT_FSIZE */ 20 #include <linux/mm.h> 21 22 #include <asm/mmu.h> 23 #include <asm/page.h> 24 #include <asm/pgtable.h> 25 #include <linux/string.h> 26 27 #define VERIFY_READ 0 28 #define VERIFY_WRITE 1 29 30 /* 31 * On Microblaze the fs value is actually the top of the corresponding 32 * address space. 33 * 34 * The fs value determines whether argument validity checking should be 35 * performed or not. If get_fs() == USER_DS, checking is performed, with 36 * get_fs() == KERNEL_DS, checking is bypassed. 37 * 38 * For historical reasons, these macros are grossly misnamed. 39 * 40 * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal. 41 */ 42 # define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 43 44 # ifndef CONFIG_MMU 45 # define KERNEL_DS MAKE_MM_SEG(0) 46 # define USER_DS KERNEL_DS 47 # else 48 # define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) 49 # define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 50 # endif 51 52 # define get_ds() (KERNEL_DS) 53 # define get_fs() (current_thread_info()->addr_limit) 54 # define set_fs(val) (current_thread_info()->addr_limit = (val)) 55 56 # define segment_eq(a, b) ((a).seg == (b).seg) 57 58 /* 59 * The exception table consists of pairs of addresses: the first is the 60 * address of an instruction that is allowed to fault, and the second is 61 * the address at which the program should continue. No registers are 62 * modified, so it is entirely up to the continuation code to figure out 63 * what to do. 64 * 65 * All the routines below use bits of fixup code that are out of line 66 * with the main instruction path. This means when everything is well, 67 * we don't even have to jump over them. Further, they do not intrude 68 * on our cache or tlb entries. 69 */ 70 struct exception_table_entry { 71 unsigned long insn, fixup; 72 }; 73 74 /* Returns 0 if exception not found and fixup otherwise. */ 75 extern unsigned long search_exception_table(unsigned long); 76 77 #ifndef CONFIG_MMU 78 79 /* Check against bounds of physical memory */ 80 static inline int ___range_ok(unsigned long addr, unsigned long size) 81 { 82 return ((addr < memory_start) || 83 ((addr + size - 1) > (memory_start + memory_size - 1))); 84 } 85 86 #define __range_ok(addr, size) \ 87 ___range_ok((unsigned long)(addr), (unsigned long)(size)) 88 89 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0) 90 91 #else 92 93 /* 94 * Address is valid if: 95 * - "addr", "addr + size" and "size" are all below the limit 96 */ 97 #define access_ok(type, addr, size) \ 98 (get_fs().seg >= (((unsigned long)(addr)) | \ 99 (size) | ((unsigned long)(addr) + (size)))) 100 101 /* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n", 102 type?"WRITE":"READ",addr,size,get_fs().seg)) */ 103 104 #endif 105 106 #ifdef CONFIG_MMU 107 # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" 108 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" 109 #else 110 # define __FIXUP_SECTION ".section .discard,\"ax\"\n" 111 # define __EX_TABLE_SECTION ".section .discard,\"ax\"\n" 112 #endif 113 114 extern unsigned long __copy_tofrom_user(void __user *to, 115 const void __user *from, unsigned long size); 116 117 /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */ 118 static inline unsigned long __must_check __clear_user(void __user *to, 119 unsigned long n) 120 { 121 /* normal memset with two words to __ex_table */ 122 __asm__ __volatile__ ( \ 123 "1: sb r0, %1, r0;" \ 124 " addik %0, %0, -1;" \ 125 " bneid %0, 1b;" \ 126 " addik %1, %1, 1;" \ 127 "2: " \ 128 __EX_TABLE_SECTION \ 129 ".word 1b,2b;" \ 130 ".previous;" \ 131 : "=r"(n), "=r"(to) \ 132 : "0"(n), "1"(to) 133 ); 134 return n; 135 } 136 137 static inline unsigned long __must_check clear_user(void __user *to, 138 unsigned long n) 139 { 140 might_sleep(); 141 if (unlikely(!access_ok(VERIFY_WRITE, to, n))) 142 return n; 143 144 return __clear_user(to, n); 145 } 146 147 /* put_user and get_user macros */ 148 extern long __user_bad(void); 149 150 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 151 ({ \ 152 __asm__ __volatile__ ( \ 153 "1:" insn " %1, %2, r0;" \ 154 " addk %0, r0, r0;" \ 155 "2: " \ 156 __FIXUP_SECTION \ 157 "3: brid 2b;" \ 158 " addik %0, r0, %3;" \ 159 ".previous;" \ 160 __EX_TABLE_SECTION \ 161 ".word 1b,3b;" \ 162 ".previous;" \ 163 : "=&r"(__gu_err), "=r"(__gu_val) \ 164 : "r"(__gu_ptr), "i"(-EFAULT) \ 165 ); \ 166 }) 167 168 /** 169 * get_user: - Get a simple variable from user space. 170 * @x: Variable to store result. 171 * @ptr: Source address, in user space. 172 * 173 * Context: User context only. This function may sleep. 174 * 175 * This macro copies a single simple variable from user space to kernel 176 * space. It supports simple types like char and int, but not larger 177 * data types like structures or arrays. 178 * 179 * @ptr must have pointer-to-simple-variable type, and the result of 180 * dereferencing @ptr must be assignable to @x without a cast. 181 * 182 * Returns zero on success, or -EFAULT on error. 183 * On error, the variable @x is set to zero. 184 */ 185 #define get_user(x, ptr) \ 186 __get_user_check((x), (ptr), sizeof(*(ptr))) 187 188 #define __get_user_check(x, ptr, size) \ 189 ({ \ 190 unsigned long __gu_val = 0; \ 191 const typeof(*(ptr)) __user *__gu_addr = (ptr); \ 192 int __gu_err = 0; \ 193 \ 194 if (access_ok(VERIFY_READ, __gu_addr, size)) { \ 195 switch (size) { \ 196 case 1: \ 197 __get_user_asm("lbu", __gu_addr, __gu_val, \ 198 __gu_err); \ 199 break; \ 200 case 2: \ 201 __get_user_asm("lhu", __gu_addr, __gu_val, \ 202 __gu_err); \ 203 break; \ 204 case 4: \ 205 __get_user_asm("lw", __gu_addr, __gu_val, \ 206 __gu_err); \ 207 break; \ 208 default: \ 209 __gu_err = __user_bad(); \ 210 break; \ 211 } \ 212 } else { \ 213 __gu_err = -EFAULT; \ 214 } \ 215 x = (typeof(*(ptr)))__gu_val; \ 216 __gu_err; \ 217 }) 218 219 #define __get_user(x, ptr) \ 220 ({ \ 221 unsigned long __gu_val; \ 222 /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \ 223 long __gu_err; \ 224 switch (sizeof(*(ptr))) { \ 225 case 1: \ 226 __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \ 227 break; \ 228 case 2: \ 229 __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \ 230 break; \ 231 case 4: \ 232 __get_user_asm("lw", (ptr), __gu_val, __gu_err); \ 233 break; \ 234 default: \ 235 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ 236 } \ 237 x = (__typeof__(*(ptr))) __gu_val; \ 238 __gu_err; \ 239 }) 240 241 242 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 243 ({ \ 244 __asm__ __volatile__ ( \ 245 "1:" insn " %1, %2, r0;" \ 246 " addk %0, r0, r0;" \ 247 "2: " \ 248 __FIXUP_SECTION \ 249 "3: brid 2b;" \ 250 " addik %0, r0, %3;" \ 251 ".previous;" \ 252 __EX_TABLE_SECTION \ 253 ".word 1b,3b;" \ 254 ".previous;" \ 255 : "=&r"(__gu_err) \ 256 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 257 ); \ 258 }) 259 260 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ 261 ({ \ 262 __asm__ __volatile__ (" lwi %0, %1, 0;" \ 263 "1: swi %0, %2, 0;" \ 264 " lwi %0, %1, 4;" \ 265 "2: swi %0, %2, 4;" \ 266 " addk %0, r0, r0;" \ 267 "3: " \ 268 __FIXUP_SECTION \ 269 "4: brid 3b;" \ 270 " addik %0, r0, %3;" \ 271 ".previous;" \ 272 __EX_TABLE_SECTION \ 273 ".word 1b,4b,2b,4b;" \ 274 ".previous;" \ 275 : "=&r"(__gu_err) \ 276 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 277 ); \ 278 }) 279 280 /** 281 * put_user: - Write a simple value into user space. 282 * @x: Value to copy to user space. 283 * @ptr: Destination address, in user space. 284 * 285 * Context: User context only. This function may sleep. 286 * 287 * This macro copies a single simple value from kernel space to user 288 * space. It supports simple types like char and int, but not larger 289 * data types like structures or arrays. 290 * 291 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 292 * to the result of dereferencing @ptr. 293 * 294 * Returns zero on success, or -EFAULT on error. 295 */ 296 #define put_user(x, ptr) \ 297 __put_user_check((x), (ptr), sizeof(*(ptr))) 298 299 #define __put_user_check(x, ptr, size) \ 300 ({ \ 301 typeof(*(ptr)) volatile __pu_val = x; \ 302 typeof(*(ptr)) __user *__pu_addr = (ptr); \ 303 int __pu_err = 0; \ 304 \ 305 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ 306 switch (size) { \ 307 case 1: \ 308 __put_user_asm("sb", __pu_addr, __pu_val, \ 309 __pu_err); \ 310 break; \ 311 case 2: \ 312 __put_user_asm("sh", __pu_addr, __pu_val, \ 313 __pu_err); \ 314 break; \ 315 case 4: \ 316 __put_user_asm("sw", __pu_addr, __pu_val, \ 317 __pu_err); \ 318 break; \ 319 case 8: \ 320 __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\ 321 break; \ 322 default: \ 323 __pu_err = __user_bad(); \ 324 break; \ 325 } \ 326 } else { \ 327 __pu_err = -EFAULT; \ 328 } \ 329 __pu_err; \ 330 }) 331 332 #define __put_user(x, ptr) \ 333 ({ \ 334 __typeof__(*(ptr)) volatile __gu_val = (x); \ 335 long __gu_err = 0; \ 336 switch (sizeof(__gu_val)) { \ 337 case 1: \ 338 __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ 339 break; \ 340 case 2: \ 341 __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ 342 break; \ 343 case 4: \ 344 __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ 345 break; \ 346 case 8: \ 347 __put_user_asm_8((ptr), __gu_val, __gu_err); \ 348 break; \ 349 default: \ 350 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ 351 } \ 352 __gu_err; \ 353 }) 354 355 356 /* copy_to_from_user */ 357 #define __copy_from_user(to, from, n) \ 358 __copy_tofrom_user((__force void __user *)(to), \ 359 (void __user *)(from), (n)) 360 #define __copy_from_user_inatomic(to, from, n) \ 361 __copy_from_user((to), (from), (n)) 362 363 static inline long copy_from_user(void *to, 364 const void __user *from, unsigned long n) 365 { 366 might_sleep(); 367 if (access_ok(VERIFY_READ, from, n)) 368 return __copy_from_user(to, from, n); 369 return n; 370 } 371 372 #define __copy_to_user(to, from, n) \ 373 __copy_tofrom_user((void __user *)(to), \ 374 (__force const void __user *)(from), (n)) 375 #define __copy_to_user_inatomic(to, from, n) __copy_to_user((to), (from), (n)) 376 377 static inline long copy_to_user(void __user *to, 378 const void *from, unsigned long n) 379 { 380 might_sleep(); 381 if (access_ok(VERIFY_WRITE, to, n)) 382 return __copy_to_user(to, from, n); 383 return n; 384 } 385 386 /* 387 * Copy a null terminated string from userspace. 388 */ 389 extern int __strncpy_user(char *to, const char __user *from, int len); 390 391 #define __strncpy_from_user __strncpy_user 392 393 static inline long 394 strncpy_from_user(char *dst, const char __user *src, long count) 395 { 396 if (!access_ok(VERIFY_READ, src, 1)) 397 return -EFAULT; 398 return __strncpy_from_user(dst, src, count); 399 } 400 401 /* 402 * Return the size of a string (including the ending 0) 403 * 404 * Return 0 on exception, a value greater than N if too long 405 */ 406 extern int __strnlen_user(const char __user *sstr, int len); 407 408 static inline long strnlen_user(const char __user *src, long n) 409 { 410 if (!access_ok(VERIFY_READ, src, 1)) 411 return 0; 412 return __strnlen_user(src, n); 413 } 414 415 #endif /* __ASSEMBLY__ */ 416 #endif /* __KERNEL__ */ 417 418 #endif /* _ASM_MICROBLAZE_UACCESS_H */ 419