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 #include <linux/kernel.h> 15 #include <linux/mm.h> 16 17 #include <asm/mmu.h> 18 #include <asm/page.h> 19 #include <asm/pgtable.h> 20 #include <linux/string.h> 21 22 /* 23 * On Microblaze the fs value is actually the top of the corresponding 24 * address space. 25 * 26 * The fs value determines whether argument validity checking should be 27 * performed or not. If get_fs() == USER_DS, checking is performed, with 28 * get_fs() == KERNEL_DS, checking is bypassed. 29 * 30 * For historical reasons, these macros are grossly misnamed. 31 * 32 * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal. 33 */ 34 # define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 35 36 # ifndef CONFIG_MMU 37 # define KERNEL_DS MAKE_MM_SEG(0) 38 # define USER_DS KERNEL_DS 39 # else 40 # define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) 41 # define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 42 # endif 43 44 # define get_ds() (KERNEL_DS) 45 # define get_fs() (current_thread_info()->addr_limit) 46 # define set_fs(val) (current_thread_info()->addr_limit = (val)) 47 48 # define segment_eq(a, b) ((a).seg == (b).seg) 49 50 /* 51 * The exception table consists of pairs of addresses: the first is the 52 * address of an instruction that is allowed to fault, and the second is 53 * the address at which the program should continue. No registers are 54 * modified, so it is entirely up to the continuation code to figure out 55 * what to do. 56 * 57 * All the routines below use bits of fixup code that are out of line 58 * with the main instruction path. This means when everything is well, 59 * we don't even have to jump over them. Further, they do not intrude 60 * on our cache or tlb entries. 61 */ 62 struct exception_table_entry { 63 unsigned long insn, fixup; 64 }; 65 66 #ifndef CONFIG_MMU 67 68 /* Check against bounds of physical memory */ 69 static inline int ___range_ok(unsigned long addr, unsigned long size) 70 { 71 return ((addr < memory_start) || 72 ((addr + size - 1) > (memory_start + memory_size - 1))); 73 } 74 75 #define __range_ok(addr, size) \ 76 ___range_ok((unsigned long)(addr), (unsigned long)(size)) 77 78 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0) 79 80 #else 81 82 static inline int access_ok(int type, const void __user *addr, 83 unsigned long size) 84 { 85 if (!size) 86 goto ok; 87 88 if ((get_fs().seg < ((unsigned long)addr)) || 89 (get_fs().seg < ((unsigned long)addr + size - 1))) { 90 pr_devel("ACCESS fail: %s at 0x%08x (size 0x%x), seg 0x%08x\n", 91 type ? "WRITE" : "READ ", (__force u32)addr, (u32)size, 92 (u32)get_fs().seg); 93 return 0; 94 } 95 ok: 96 pr_devel("ACCESS OK: %s at 0x%08x (size 0x%x), seg 0x%08x\n", 97 type ? "WRITE" : "READ ", (__force u32)addr, (u32)size, 98 (u32)get_fs().seg); 99 return 1; 100 } 101 #endif 102 103 #ifdef CONFIG_MMU 104 # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" 105 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" 106 #else 107 # define __FIXUP_SECTION ".section .discard,\"ax\"\n" 108 # define __EX_TABLE_SECTION ".section .discard,\"ax\"\n" 109 #endif 110 111 extern unsigned long __copy_tofrom_user(void __user *to, 112 const void __user *from, unsigned long size); 113 114 /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */ 115 static inline unsigned long __must_check __clear_user(void __user *to, 116 unsigned long n) 117 { 118 /* normal memset with two words to __ex_table */ 119 __asm__ __volatile__ ( \ 120 "1: sb r0, %1, r0;" \ 121 " addik %0, %0, -1;" \ 122 " bneid %0, 1b;" \ 123 " addik %1, %1, 1;" \ 124 "2: " \ 125 __EX_TABLE_SECTION \ 126 ".word 1b,2b;" \ 127 ".previous;" \ 128 : "=r"(n), "=r"(to) \ 129 : "0"(n), "1"(to) 130 ); 131 return n; 132 } 133 134 static inline unsigned long __must_check clear_user(void __user *to, 135 unsigned long n) 136 { 137 might_fault(); 138 if (unlikely(!access_ok(VERIFY_WRITE, to, n))) 139 return n; 140 141 return __clear_user(to, n); 142 } 143 144 /* put_user and get_user macros */ 145 extern long __user_bad(void); 146 147 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 148 ({ \ 149 __asm__ __volatile__ ( \ 150 "1:" insn " %1, %2, r0;" \ 151 " addk %0, r0, r0;" \ 152 "2: " \ 153 __FIXUP_SECTION \ 154 "3: brid 2b;" \ 155 " addik %0, r0, %3;" \ 156 ".previous;" \ 157 __EX_TABLE_SECTION \ 158 ".word 1b,3b;" \ 159 ".previous;" \ 160 : "=&r"(__gu_err), "=r"(__gu_val) \ 161 : "r"(__gu_ptr), "i"(-EFAULT) \ 162 ); \ 163 }) 164 165 /** 166 * get_user: - Get a simple variable from user space. 167 * @x: Variable to store result. 168 * @ptr: Source address, in user space. 169 * 170 * Context: User context only. This function may sleep if pagefaults are 171 * enabled. 172 * 173 * This macro copies a single simple variable from user space to kernel 174 * space. It supports simple types like char and int, but not larger 175 * data types like structures or arrays. 176 * 177 * @ptr must have pointer-to-simple-variable type, and the result of 178 * dereferencing @ptr must be assignable to @x without a cast. 179 * 180 * Returns zero on success, or -EFAULT on error. 181 * On error, the variable @x is set to zero. 182 */ 183 #define get_user(x, ptr) \ 184 __get_user_check((x), (ptr), sizeof(*(ptr))) 185 186 #define __get_user_check(x, ptr, size) \ 187 ({ \ 188 unsigned long __gu_val = 0; \ 189 const typeof(*(ptr)) __user *__gu_addr = (ptr); \ 190 int __gu_err = 0; \ 191 \ 192 if (access_ok(VERIFY_READ, __gu_addr, size)) { \ 193 switch (size) { \ 194 case 1: \ 195 __get_user_asm("lbu", __gu_addr, __gu_val, \ 196 __gu_err); \ 197 break; \ 198 case 2: \ 199 __get_user_asm("lhu", __gu_addr, __gu_val, \ 200 __gu_err); \ 201 break; \ 202 case 4: \ 203 __get_user_asm("lw", __gu_addr, __gu_val, \ 204 __gu_err); \ 205 break; \ 206 default: \ 207 __gu_err = __user_bad(); \ 208 break; \ 209 } \ 210 } else { \ 211 __gu_err = -EFAULT; \ 212 } \ 213 x = (__force typeof(*(ptr)))__gu_val; \ 214 __gu_err; \ 215 }) 216 217 #define __get_user(x, ptr) \ 218 ({ \ 219 unsigned long __gu_val = 0; \ 220 /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \ 221 long __gu_err; \ 222 switch (sizeof(*(ptr))) { \ 223 case 1: \ 224 __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \ 225 break; \ 226 case 2: \ 227 __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \ 228 break; \ 229 case 4: \ 230 __get_user_asm("lw", (ptr), __gu_val, __gu_err); \ 231 break; \ 232 default: \ 233 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ 234 } \ 235 x = (__force __typeof__(*(ptr))) __gu_val; \ 236 __gu_err; \ 237 }) 238 239 240 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 241 ({ \ 242 __asm__ __volatile__ ( \ 243 "1:" insn " %1, %2, r0;" \ 244 " addk %0, r0, r0;" \ 245 "2: " \ 246 __FIXUP_SECTION \ 247 "3: brid 2b;" \ 248 " addik %0, r0, %3;" \ 249 ".previous;" \ 250 __EX_TABLE_SECTION \ 251 ".word 1b,3b;" \ 252 ".previous;" \ 253 : "=&r"(__gu_err) \ 254 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 255 ); \ 256 }) 257 258 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ 259 ({ \ 260 __asm__ __volatile__ (" lwi %0, %1, 0;" \ 261 "1: swi %0, %2, 0;" \ 262 " lwi %0, %1, 4;" \ 263 "2: swi %0, %2, 4;" \ 264 " addk %0, r0, r0;" \ 265 "3: " \ 266 __FIXUP_SECTION \ 267 "4: brid 3b;" \ 268 " addik %0, r0, %3;" \ 269 ".previous;" \ 270 __EX_TABLE_SECTION \ 271 ".word 1b,4b,2b,4b;" \ 272 ".previous;" \ 273 : "=&r"(__gu_err) \ 274 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 275 ); \ 276 }) 277 278 /** 279 * put_user: - Write a simple value into user space. 280 * @x: Value to copy to user space. 281 * @ptr: Destination address, in user space. 282 * 283 * Context: User context only. This function may sleep if pagefaults are 284 * enabled. 285 * 286 * This macro copies a single simple value from kernel space to user 287 * space. It supports simple types like char and int, but not larger 288 * data types like structures or arrays. 289 * 290 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 291 * to the result of dereferencing @ptr. 292 * 293 * Returns zero on success, or -EFAULT on error. 294 */ 295 #define put_user(x, ptr) \ 296 __put_user_check((x), (ptr), sizeof(*(ptr))) 297 298 #define __put_user_check(x, ptr, size) \ 299 ({ \ 300 typeof(*(ptr)) volatile __pu_val = x; \ 301 typeof(*(ptr)) __user *__pu_addr = (ptr); \ 302 int __pu_err = 0; \ 303 \ 304 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ 305 switch (size) { \ 306 case 1: \ 307 __put_user_asm("sb", __pu_addr, __pu_val, \ 308 __pu_err); \ 309 break; \ 310 case 2: \ 311 __put_user_asm("sh", __pu_addr, __pu_val, \ 312 __pu_err); \ 313 break; \ 314 case 4: \ 315 __put_user_asm("sw", __pu_addr, __pu_val, \ 316 __pu_err); \ 317 break; \ 318 case 8: \ 319 __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\ 320 break; \ 321 default: \ 322 __pu_err = __user_bad(); \ 323 break; \ 324 } \ 325 } else { \ 326 __pu_err = -EFAULT; \ 327 } \ 328 __pu_err; \ 329 }) 330 331 #define __put_user(x, ptr) \ 332 ({ \ 333 __typeof__(*(ptr)) volatile __gu_val = (x); \ 334 long __gu_err = 0; \ 335 switch (sizeof(__gu_val)) { \ 336 case 1: \ 337 __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ 338 break; \ 339 case 2: \ 340 __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ 341 break; \ 342 case 4: \ 343 __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ 344 break; \ 345 case 8: \ 346 __put_user_asm_8((ptr), __gu_val, __gu_err); \ 347 break; \ 348 default: \ 349 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ 350 } \ 351 __gu_err; \ 352 }) 353 354 355 /* copy_to_from_user */ 356 #define __copy_from_user(to, from, n) \ 357 __copy_tofrom_user((__force void __user *)(to), \ 358 (void __user *)(from), (n)) 359 #define __copy_from_user_inatomic(to, from, n) \ 360 __copy_from_user((to), (from), (n)) 361 362 static inline long copy_from_user(void *to, 363 const void __user *from, unsigned long n) 364 { 365 unsigned long res = n; 366 might_fault(); 367 if (likely(access_ok(VERIFY_READ, from, n))) 368 res = __copy_from_user(to, from, n); 369 if (unlikely(res)) 370 memset(to + (n - res), 0, res); 371 return res; 372 } 373 374 #define __copy_to_user(to, from, n) \ 375 __copy_tofrom_user((void __user *)(to), \ 376 (__force const void __user *)(from), (n)) 377 #define __copy_to_user_inatomic(to, from, n) __copy_to_user((to), (from), (n)) 378 379 static inline long copy_to_user(void __user *to, 380 const void *from, unsigned long n) 381 { 382 might_fault(); 383 if (access_ok(VERIFY_WRITE, to, n)) 384 return __copy_to_user(to, from, n); 385 return n; 386 } 387 388 /* 389 * Copy a null terminated string from userspace. 390 */ 391 extern int __strncpy_user(char *to, const char __user *from, int len); 392 393 #define __strncpy_from_user __strncpy_user 394 395 static inline long 396 strncpy_from_user(char *dst, const char __user *src, long count) 397 { 398 if (!access_ok(VERIFY_READ, src, 1)) 399 return -EFAULT; 400 return __strncpy_from_user(dst, src, count); 401 } 402 403 /* 404 * Return the size of a string (including the ending 0) 405 * 406 * Return 0 on exception, a value greater than N if too long 407 */ 408 extern int __strnlen_user(const char __user *sstr, int len); 409 410 static inline long strnlen_user(const char __user *src, long n) 411 { 412 if (!access_ok(VERIFY_READ, src, 1)) 413 return 0; 414 return __strnlen_user(src, n); 415 } 416 417 #endif /* _ASM_MICROBLAZE_UACCESS_H */ 418