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 <asm/extable.h> 21 #include <linux/string.h> 22 23 /* 24 * On Microblaze the fs value is actually the top of the corresponding 25 * address space. 26 * 27 * The fs value determines whether argument validity checking should be 28 * performed or not. If get_fs() == USER_DS, checking is performed, with 29 * get_fs() == KERNEL_DS, checking is bypassed. 30 * 31 * For historical reasons, these macros are grossly misnamed. 32 * 33 * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal. 34 */ 35 # define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 36 37 # ifndef CONFIG_MMU 38 # define KERNEL_DS MAKE_MM_SEG(0) 39 # define USER_DS KERNEL_DS 40 # else 41 # define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) 42 # define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 43 # endif 44 45 # define get_ds() (KERNEL_DS) 46 # define get_fs() (current_thread_info()->addr_limit) 47 # define set_fs(val) (current_thread_info()->addr_limit = (val)) 48 49 # define segment_eq(a, b) ((a).seg == (b).seg) 50 51 #ifndef CONFIG_MMU 52 53 /* Check against bounds of physical memory */ 54 static inline int ___range_ok(unsigned long addr, unsigned long size) 55 { 56 return ((addr < memory_start) || 57 ((addr + size - 1) > (memory_start + memory_size - 1))); 58 } 59 60 #define __range_ok(addr, size) \ 61 ___range_ok((unsigned long)(addr), (unsigned long)(size)) 62 63 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0) 64 65 #else 66 67 static inline int access_ok(int type, const void __user *addr, 68 unsigned long size) 69 { 70 if (!size) 71 goto ok; 72 73 if ((get_fs().seg < ((unsigned long)addr)) || 74 (get_fs().seg < ((unsigned long)addr + size - 1))) { 75 pr_devel("ACCESS fail: %s at 0x%08x (size 0x%x), seg 0x%08x\n", 76 type ? "WRITE" : "READ ", (__force u32)addr, (u32)size, 77 (u32)get_fs().seg); 78 return 0; 79 } 80 ok: 81 pr_devel("ACCESS OK: %s at 0x%08x (size 0x%x), seg 0x%08x\n", 82 type ? "WRITE" : "READ ", (__force u32)addr, (u32)size, 83 (u32)get_fs().seg); 84 return 1; 85 } 86 #endif 87 88 #ifdef CONFIG_MMU 89 # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" 90 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" 91 #else 92 # define __FIXUP_SECTION ".section .discard,\"ax\"\n" 93 # define __EX_TABLE_SECTION ".section .discard,\"ax\"\n" 94 #endif 95 96 extern unsigned long __copy_tofrom_user(void __user *to, 97 const void __user *from, unsigned long size); 98 99 /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */ 100 static inline unsigned long __must_check __clear_user(void __user *to, 101 unsigned long n) 102 { 103 /* normal memset with two words to __ex_table */ 104 __asm__ __volatile__ ( \ 105 "1: sb r0, %1, r0;" \ 106 " addik %0, %0, -1;" \ 107 " bneid %0, 1b;" \ 108 " addik %1, %1, 1;" \ 109 "2: " \ 110 __EX_TABLE_SECTION \ 111 ".word 1b,2b;" \ 112 ".previous;" \ 113 : "=r"(n), "=r"(to) \ 114 : "0"(n), "1"(to) 115 ); 116 return n; 117 } 118 119 static inline unsigned long __must_check clear_user(void __user *to, 120 unsigned long n) 121 { 122 might_fault(); 123 if (unlikely(!access_ok(VERIFY_WRITE, to, n))) 124 return n; 125 126 return __clear_user(to, n); 127 } 128 129 /* put_user and get_user macros */ 130 extern long __user_bad(void); 131 132 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 133 ({ \ 134 __asm__ __volatile__ ( \ 135 "1:" insn " %1, %2, r0;" \ 136 " addk %0, r0, r0;" \ 137 "2: " \ 138 __FIXUP_SECTION \ 139 "3: brid 2b;" \ 140 " addik %0, r0, %3;" \ 141 ".previous;" \ 142 __EX_TABLE_SECTION \ 143 ".word 1b,3b;" \ 144 ".previous;" \ 145 : "=&r"(__gu_err), "=r"(__gu_val) \ 146 : "r"(__gu_ptr), "i"(-EFAULT) \ 147 ); \ 148 }) 149 150 /** 151 * get_user: - Get a simple variable from user space. 152 * @x: Variable to store result. 153 * @ptr: Source address, in user space. 154 * 155 * Context: User context only. This function may sleep if pagefaults are 156 * enabled. 157 * 158 * This macro copies a single simple variable from user space to kernel 159 * space. It supports simple types like char and int, but not larger 160 * data types like structures or arrays. 161 * 162 * @ptr must have pointer-to-simple-variable type, and the result of 163 * dereferencing @ptr must be assignable to @x without a cast. 164 * 165 * Returns zero on success, or -EFAULT on error. 166 * On error, the variable @x is set to zero. 167 */ 168 #define get_user(x, ptr) \ 169 __get_user_check((x), (ptr), sizeof(*(ptr))) 170 171 #define __get_user_check(x, ptr, size) \ 172 ({ \ 173 unsigned long __gu_val = 0; \ 174 const typeof(*(ptr)) __user *__gu_addr = (ptr); \ 175 int __gu_err = 0; \ 176 \ 177 if (access_ok(VERIFY_READ, __gu_addr, size)) { \ 178 switch (size) { \ 179 case 1: \ 180 __get_user_asm("lbu", __gu_addr, __gu_val, \ 181 __gu_err); \ 182 break; \ 183 case 2: \ 184 __get_user_asm("lhu", __gu_addr, __gu_val, \ 185 __gu_err); \ 186 break; \ 187 case 4: \ 188 __get_user_asm("lw", __gu_addr, __gu_val, \ 189 __gu_err); \ 190 break; \ 191 default: \ 192 __gu_err = __user_bad(); \ 193 break; \ 194 } \ 195 } else { \ 196 __gu_err = -EFAULT; \ 197 } \ 198 x = (__force typeof(*(ptr)))__gu_val; \ 199 __gu_err; \ 200 }) 201 202 #define __get_user(x, ptr) \ 203 ({ \ 204 unsigned long __gu_val = 0; \ 205 /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \ 206 long __gu_err; \ 207 switch (sizeof(*(ptr))) { \ 208 case 1: \ 209 __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \ 210 break; \ 211 case 2: \ 212 __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \ 213 break; \ 214 case 4: \ 215 __get_user_asm("lw", (ptr), __gu_val, __gu_err); \ 216 break; \ 217 default: \ 218 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ 219 } \ 220 x = (__force __typeof__(*(ptr))) __gu_val; \ 221 __gu_err; \ 222 }) 223 224 225 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 226 ({ \ 227 __asm__ __volatile__ ( \ 228 "1:" insn " %1, %2, r0;" \ 229 " addk %0, r0, r0;" \ 230 "2: " \ 231 __FIXUP_SECTION \ 232 "3: brid 2b;" \ 233 " addik %0, r0, %3;" \ 234 ".previous;" \ 235 __EX_TABLE_SECTION \ 236 ".word 1b,3b;" \ 237 ".previous;" \ 238 : "=&r"(__gu_err) \ 239 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 240 ); \ 241 }) 242 243 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ 244 ({ \ 245 __asm__ __volatile__ (" lwi %0, %1, 0;" \ 246 "1: swi %0, %2, 0;" \ 247 " lwi %0, %1, 4;" \ 248 "2: swi %0, %2, 4;" \ 249 " addk %0, r0, r0;" \ 250 "3: " \ 251 __FIXUP_SECTION \ 252 "4: brid 3b;" \ 253 " addik %0, r0, %3;" \ 254 ".previous;" \ 255 __EX_TABLE_SECTION \ 256 ".word 1b,4b,2b,4b;" \ 257 ".previous;" \ 258 : "=&r"(__gu_err) \ 259 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 260 ); \ 261 }) 262 263 /** 264 * put_user: - Write a simple value into user space. 265 * @x: Value to copy to user space. 266 * @ptr: Destination address, in user space. 267 * 268 * Context: User context only. This function may sleep if pagefaults are 269 * enabled. 270 * 271 * This macro copies a single simple value from kernel space to user 272 * space. It supports simple types like char and int, but not larger 273 * data types like structures or arrays. 274 * 275 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 276 * to the result of dereferencing @ptr. 277 * 278 * Returns zero on success, or -EFAULT on error. 279 */ 280 #define put_user(x, ptr) \ 281 __put_user_check((x), (ptr), sizeof(*(ptr))) 282 283 #define __put_user_check(x, ptr, size) \ 284 ({ \ 285 typeof(*(ptr)) volatile __pu_val = x; \ 286 typeof(*(ptr)) __user *__pu_addr = (ptr); \ 287 int __pu_err = 0; \ 288 \ 289 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ 290 switch (size) { \ 291 case 1: \ 292 __put_user_asm("sb", __pu_addr, __pu_val, \ 293 __pu_err); \ 294 break; \ 295 case 2: \ 296 __put_user_asm("sh", __pu_addr, __pu_val, \ 297 __pu_err); \ 298 break; \ 299 case 4: \ 300 __put_user_asm("sw", __pu_addr, __pu_val, \ 301 __pu_err); \ 302 break; \ 303 case 8: \ 304 __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\ 305 break; \ 306 default: \ 307 __pu_err = __user_bad(); \ 308 break; \ 309 } \ 310 } else { \ 311 __pu_err = -EFAULT; \ 312 } \ 313 __pu_err; \ 314 }) 315 316 #define __put_user(x, ptr) \ 317 ({ \ 318 __typeof__(*(ptr)) volatile __gu_val = (x); \ 319 long __gu_err = 0; \ 320 switch (sizeof(__gu_val)) { \ 321 case 1: \ 322 __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ 323 break; \ 324 case 2: \ 325 __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ 326 break; \ 327 case 4: \ 328 __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ 329 break; \ 330 case 8: \ 331 __put_user_asm_8((ptr), __gu_val, __gu_err); \ 332 break; \ 333 default: \ 334 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ 335 } \ 336 __gu_err; \ 337 }) 338 339 static inline unsigned long 340 raw_copy_from_user(void *to, const void __user *from, unsigned long n) 341 { 342 return __copy_tofrom_user((__force void __user *)to, from, n); 343 } 344 345 static inline unsigned long 346 raw_copy_to_user(void __user *to, const void *from, unsigned long n) 347 { 348 return __copy_tofrom_user(to, (__force const void __user *)from, n); 349 } 350 #define INLINE_COPY_FROM_USER 351 #define INLINE_COPY_TO_USER 352 353 /* 354 * Copy a null terminated string from userspace. 355 */ 356 extern int __strncpy_user(char *to, const char __user *from, int len); 357 358 static inline long 359 strncpy_from_user(char *dst, const char __user *src, long count) 360 { 361 if (!access_ok(VERIFY_READ, src, 1)) 362 return -EFAULT; 363 return __strncpy_user(dst, src, count); 364 } 365 366 /* 367 * Return the size of a string (including the ending 0) 368 * 369 * Return 0 on exception, a value greater than N if too long 370 */ 371 extern int __strnlen_user(const char __user *sstr, int len); 372 373 static inline long strnlen_user(const char __user *src, long n) 374 { 375 if (!access_ok(VERIFY_READ, src, 1)) 376 return 0; 377 return __strnlen_user(src, n); 378 } 379 380 #endif /* _ASM_MICROBLAZE_UACCESS_H */ 381