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 static inline int access_ok(int type, const void __user *addr, 94 unsigned long size) 95 { 96 if (!size) 97 goto ok; 98 99 if ((get_fs().seg < ((unsigned long)addr)) || 100 (get_fs().seg < ((unsigned long)addr + size - 1))) { 101 pr_devel("ACCESS fail: %s at 0x%08x (size 0x%x), seg 0x%08x\n", 102 type ? "WRITE" : "READ ", (__force u32)addr, (u32)size, 103 (u32)get_fs().seg); 104 return 0; 105 } 106 ok: 107 pr_devel("ACCESS OK: %s at 0x%08x (size 0x%x), seg 0x%08x\n", 108 type ? "WRITE" : "READ ", (__force u32)addr, (u32)size, 109 (u32)get_fs().seg); 110 return 1; 111 } 112 #endif 113 114 #ifdef CONFIG_MMU 115 # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" 116 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" 117 #else 118 # define __FIXUP_SECTION ".section .discard,\"ax\"\n" 119 # define __EX_TABLE_SECTION ".section .discard,\"ax\"\n" 120 #endif 121 122 extern unsigned long __copy_tofrom_user(void __user *to, 123 const void __user *from, unsigned long size); 124 125 /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */ 126 static inline unsigned long __must_check __clear_user(void __user *to, 127 unsigned long n) 128 { 129 /* normal memset with two words to __ex_table */ 130 __asm__ __volatile__ ( \ 131 "1: sb r0, %1, r0;" \ 132 " addik %0, %0, -1;" \ 133 " bneid %0, 1b;" \ 134 " addik %1, %1, 1;" \ 135 "2: " \ 136 __EX_TABLE_SECTION \ 137 ".word 1b,2b;" \ 138 ".previous;" \ 139 : "=r"(n), "=r"(to) \ 140 : "0"(n), "1"(to) 141 ); 142 return n; 143 } 144 145 static inline unsigned long __must_check clear_user(void __user *to, 146 unsigned long n) 147 { 148 might_fault(); 149 if (unlikely(!access_ok(VERIFY_WRITE, to, n))) 150 return n; 151 152 return __clear_user(to, n); 153 } 154 155 /* put_user and get_user macros */ 156 extern long __user_bad(void); 157 158 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 159 ({ \ 160 __asm__ __volatile__ ( \ 161 "1:" insn " %1, %2, r0;" \ 162 " addk %0, r0, r0;" \ 163 "2: " \ 164 __FIXUP_SECTION \ 165 "3: brid 2b;" \ 166 " addik %0, r0, %3;" \ 167 ".previous;" \ 168 __EX_TABLE_SECTION \ 169 ".word 1b,3b;" \ 170 ".previous;" \ 171 : "=&r"(__gu_err), "=r"(__gu_val) \ 172 : "r"(__gu_ptr), "i"(-EFAULT) \ 173 ); \ 174 }) 175 176 /** 177 * get_user: - Get a simple variable from user space. 178 * @x: Variable to store result. 179 * @ptr: Source address, in user space. 180 * 181 * Context: User context only. This function may sleep. 182 * 183 * This macro copies a single simple variable from user space to kernel 184 * space. It supports simple types like char and int, but not larger 185 * data types like structures or arrays. 186 * 187 * @ptr must have pointer-to-simple-variable type, and the result of 188 * dereferencing @ptr must be assignable to @x without a cast. 189 * 190 * Returns zero on success, or -EFAULT on error. 191 * On error, the variable @x is set to zero. 192 */ 193 #define get_user(x, ptr) \ 194 __get_user_check((x), (ptr), sizeof(*(ptr))) 195 196 #define __get_user_check(x, ptr, size) \ 197 ({ \ 198 unsigned long __gu_val = 0; \ 199 const typeof(*(ptr)) __user *__gu_addr = (ptr); \ 200 int __gu_err = 0; \ 201 \ 202 if (access_ok(VERIFY_READ, __gu_addr, size)) { \ 203 switch (size) { \ 204 case 1: \ 205 __get_user_asm("lbu", __gu_addr, __gu_val, \ 206 __gu_err); \ 207 break; \ 208 case 2: \ 209 __get_user_asm("lhu", __gu_addr, __gu_val, \ 210 __gu_err); \ 211 break; \ 212 case 4: \ 213 __get_user_asm("lw", __gu_addr, __gu_val, \ 214 __gu_err); \ 215 break; \ 216 default: \ 217 __gu_err = __user_bad(); \ 218 break; \ 219 } \ 220 } else { \ 221 __gu_err = -EFAULT; \ 222 } \ 223 x = (__force typeof(*(ptr)))__gu_val; \ 224 __gu_err; \ 225 }) 226 227 #define __get_user(x, ptr) \ 228 ({ \ 229 unsigned long __gu_val; \ 230 /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \ 231 long __gu_err; \ 232 switch (sizeof(*(ptr))) { \ 233 case 1: \ 234 __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \ 235 break; \ 236 case 2: \ 237 __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \ 238 break; \ 239 case 4: \ 240 __get_user_asm("lw", (ptr), __gu_val, __gu_err); \ 241 break; \ 242 default: \ 243 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ 244 } \ 245 x = (__force __typeof__(*(ptr))) __gu_val; \ 246 __gu_err; \ 247 }) 248 249 250 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 251 ({ \ 252 __asm__ __volatile__ ( \ 253 "1:" insn " %1, %2, r0;" \ 254 " addk %0, r0, r0;" \ 255 "2: " \ 256 __FIXUP_SECTION \ 257 "3: brid 2b;" \ 258 " addik %0, r0, %3;" \ 259 ".previous;" \ 260 __EX_TABLE_SECTION \ 261 ".word 1b,3b;" \ 262 ".previous;" \ 263 : "=&r"(__gu_err) \ 264 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 265 ); \ 266 }) 267 268 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ 269 ({ \ 270 __asm__ __volatile__ (" lwi %0, %1, 0;" \ 271 "1: swi %0, %2, 0;" \ 272 " lwi %0, %1, 4;" \ 273 "2: swi %0, %2, 4;" \ 274 " addk %0, r0, r0;" \ 275 "3: " \ 276 __FIXUP_SECTION \ 277 "4: brid 3b;" \ 278 " addik %0, r0, %3;" \ 279 ".previous;" \ 280 __EX_TABLE_SECTION \ 281 ".word 1b,4b,2b,4b;" \ 282 ".previous;" \ 283 : "=&r"(__gu_err) \ 284 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 285 ); \ 286 }) 287 288 /** 289 * put_user: - Write a simple value into user space. 290 * @x: Value to copy to user space. 291 * @ptr: Destination address, in user space. 292 * 293 * Context: User context only. This function may sleep. 294 * 295 * This macro copies a single simple value from kernel space to user 296 * space. It supports simple types like char and int, but not larger 297 * data types like structures or arrays. 298 * 299 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 300 * to the result of dereferencing @ptr. 301 * 302 * Returns zero on success, or -EFAULT on error. 303 */ 304 #define put_user(x, ptr) \ 305 __put_user_check((x), (ptr), sizeof(*(ptr))) 306 307 #define __put_user_check(x, ptr, size) \ 308 ({ \ 309 typeof(*(ptr)) volatile __pu_val = x; \ 310 typeof(*(ptr)) __user *__pu_addr = (ptr); \ 311 int __pu_err = 0; \ 312 \ 313 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ 314 switch (size) { \ 315 case 1: \ 316 __put_user_asm("sb", __pu_addr, __pu_val, \ 317 __pu_err); \ 318 break; \ 319 case 2: \ 320 __put_user_asm("sh", __pu_addr, __pu_val, \ 321 __pu_err); \ 322 break; \ 323 case 4: \ 324 __put_user_asm("sw", __pu_addr, __pu_val, \ 325 __pu_err); \ 326 break; \ 327 case 8: \ 328 __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\ 329 break; \ 330 default: \ 331 __pu_err = __user_bad(); \ 332 break; \ 333 } \ 334 } else { \ 335 __pu_err = -EFAULT; \ 336 } \ 337 __pu_err; \ 338 }) 339 340 #define __put_user(x, ptr) \ 341 ({ \ 342 __typeof__(*(ptr)) volatile __gu_val = (x); \ 343 long __gu_err = 0; \ 344 switch (sizeof(__gu_val)) { \ 345 case 1: \ 346 __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ 347 break; \ 348 case 2: \ 349 __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ 350 break; \ 351 case 4: \ 352 __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ 353 break; \ 354 case 8: \ 355 __put_user_asm_8((ptr), __gu_val, __gu_err); \ 356 break; \ 357 default: \ 358 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ 359 } \ 360 __gu_err; \ 361 }) 362 363 364 /* copy_to_from_user */ 365 #define __copy_from_user(to, from, n) \ 366 __copy_tofrom_user((__force void __user *)(to), \ 367 (void __user *)(from), (n)) 368 #define __copy_from_user_inatomic(to, from, n) \ 369 __copy_from_user((to), (from), (n)) 370 371 static inline long copy_from_user(void *to, 372 const void __user *from, unsigned long n) 373 { 374 might_fault(); 375 if (access_ok(VERIFY_READ, from, n)) 376 return __copy_from_user(to, from, n); 377 return n; 378 } 379 380 #define __copy_to_user(to, from, n) \ 381 __copy_tofrom_user((void __user *)(to), \ 382 (__force const void __user *)(from), (n)) 383 #define __copy_to_user_inatomic(to, from, n) __copy_to_user((to), (from), (n)) 384 385 static inline long copy_to_user(void __user *to, 386 const void *from, unsigned long n) 387 { 388 might_fault(); 389 if (access_ok(VERIFY_WRITE, to, n)) 390 return __copy_to_user(to, from, n); 391 return n; 392 } 393 394 /* 395 * Copy a null terminated string from userspace. 396 */ 397 extern int __strncpy_user(char *to, const char __user *from, int len); 398 399 #define __strncpy_from_user __strncpy_user 400 401 static inline long 402 strncpy_from_user(char *dst, const char __user *src, long count) 403 { 404 if (!access_ok(VERIFY_READ, src, 1)) 405 return -EFAULT; 406 return __strncpy_from_user(dst, src, count); 407 } 408 409 /* 410 * Return the size of a string (including the ending 0) 411 * 412 * Return 0 on exception, a value greater than N if too long 413 */ 414 extern int __strnlen_user(const char __user *sstr, int len); 415 416 static inline long strnlen_user(const char __user *src, long n) 417 { 418 if (!access_ok(VERIFY_READ, src, 1)) 419 return 0; 420 return __strnlen_user(src, n); 421 } 422 423 #endif /* __ASSEMBLY__ */ 424 #endif /* __KERNEL__ */ 425 426 #endif /* _ASM_MICROBLAZE_UACCESS_H */ 427