| 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 = (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 = (__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 */ |