Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifdef __KERNEL__ |
| 2 | #ifndef _PPC_UACCESS_H |
| 3 | #define _PPC_UACCESS_H |
| 4 | |
| 5 | #ifndef __ASSEMBLY__ |
| 6 | #include <linux/sched.h> |
| 7 | #include <linux/errno.h> |
| 8 | #include <asm/processor.h> |
| 9 | |
| 10 | #define VERIFY_READ 0 |
| 11 | #define VERIFY_WRITE 1 |
| 12 | |
| 13 | /* |
| 14 | * The fs value determines whether argument validity checking should be |
| 15 | * performed or not. If get_fs() == USER_DS, checking is performed, with |
| 16 | * get_fs() == KERNEL_DS, checking is bypassed. |
| 17 | * |
| 18 | * For historical reasons, these macros are grossly misnamed. |
| 19 | * |
| 20 | * The fs/ds values are now the highest legal address in the "segment". |
| 21 | * This simplifies the checking in the routines below. |
| 22 | */ |
| 23 | |
| 24 | #define KERNEL_DS ((mm_segment_t) { ~0UL }) |
| 25 | #define USER_DS ((mm_segment_t) { TASK_SIZE - 1 }) |
| 26 | |
| 27 | #define get_ds() (KERNEL_DS) |
| 28 | #define get_fs() (current->thread.fs) |
| 29 | #define set_fs(val) (current->thread.fs = (val)) |
| 30 | |
| 31 | #define segment_eq(a,b) ((a).seg == (b).seg) |
| 32 | |
| 33 | #define __access_ok(addr,size) \ |
| 34 | ((addr) <= current->thread.fs.seg \ |
| 35 | && ((size) == 0 || (size) - 1 <= current->thread.fs.seg - (addr))) |
| 36 | |
| 37 | #define access_ok(type, addr, size) \ |
| 38 | (__chk_user_ptr(addr),__access_ok((unsigned long)(addr),(size))) |
| 39 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | /* |
| 41 | * The exception table consists of pairs of addresses: the first is the |
| 42 | * address of an instruction that is allowed to fault, and the second is |
| 43 | * the address at which the program should continue. No registers are |
| 44 | * modified, so it is entirely up to the continuation code to figure out |
| 45 | * what to do. |
| 46 | * |
| 47 | * All the routines below use bits of fixup code that are out of line |
| 48 | * with the main instruction path. This means when everything is well, |
| 49 | * we don't even have to jump over them. Further, they do not intrude |
| 50 | * on our cache or tlb entries. |
| 51 | */ |
| 52 | |
| 53 | struct exception_table_entry |
| 54 | { |
| 55 | unsigned long insn, fixup; |
| 56 | }; |
| 57 | |
| 58 | /* |
| 59 | * These are the main single-value transfer routines. They automatically |
| 60 | * use the right size if we just have the right pointer type. |
| 61 | * |
| 62 | * This gets kind of ugly. We want to return _two_ values in "get_user()" |
| 63 | * and yet we don't want to do any pointers, because that is too much |
| 64 | * of a performance impact. Thus we have a few rather ugly macros here, |
| 65 | * and hide all the ugliness from the user. |
| 66 | * |
| 67 | * The "__xxx" versions of the user access functions are versions that |
| 68 | * do not verify the address space, that must have been done previously |
| 69 | * with a separate "access_ok()" call (this is used when we do multiple |
| 70 | * accesses to the same area of user memory). |
| 71 | * |
| 72 | * As we use the same address space for kernel and user data on the |
| 73 | * PowerPC, we can just do these as direct assignments. (Of course, the |
| 74 | * exception handling means that it's no longer "just"...) |
| 75 | * |
| 76 | * The "user64" versions of the user access functions are versions that |
| 77 | * allow access of 64-bit data. The "get_user" functions do not |
| 78 | * properly handle 64-bit data because the value gets down cast to a long. |
| 79 | * The "put_user" functions already handle 64-bit data properly but we add |
| 80 | * "user64" versions for completeness |
| 81 | */ |
| 82 | #define get_user(x,ptr) \ |
| 83 | __get_user_check((x),(ptr),sizeof(*(ptr))) |
| 84 | #define get_user64(x,ptr) \ |
| 85 | __get_user64_check((x),(ptr),sizeof(*(ptr))) |
| 86 | #define put_user(x,ptr) \ |
| 87 | __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) |
| 88 | #define put_user64(x,ptr) put_user(x,ptr) |
| 89 | |
| 90 | #define __get_user(x,ptr) \ |
| 91 | __get_user_nocheck((x),(ptr),sizeof(*(ptr))) |
| 92 | #define __get_user64(x,ptr) \ |
| 93 | __get_user64_nocheck((x),(ptr),sizeof(*(ptr))) |
| 94 | #define __put_user(x,ptr) \ |
| 95 | __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) |
| 96 | #define __put_user64(x,ptr) __put_user(x,ptr) |
| 97 | |
| 98 | extern long __put_user_bad(void); |
| 99 | |
| 100 | #define __put_user_nocheck(x,ptr,size) \ |
| 101 | ({ \ |
| 102 | long __pu_err; \ |
| 103 | __chk_user_ptr(ptr); \ |
| 104 | __put_user_size((x),(ptr),(size),__pu_err); \ |
| 105 | __pu_err; \ |
| 106 | }) |
| 107 | |
| 108 | #define __put_user_check(x,ptr,size) \ |
| 109 | ({ \ |
| 110 | long __pu_err = -EFAULT; \ |
| 111 | __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ |
| 112 | if (access_ok(VERIFY_WRITE,__pu_addr,size)) \ |
| 113 | __put_user_size((x),__pu_addr,(size),__pu_err); \ |
| 114 | __pu_err; \ |
| 115 | }) |
| 116 | |
| 117 | #define __put_user_size(x,ptr,size,retval) \ |
| 118 | do { \ |
| 119 | retval = 0; \ |
| 120 | switch (size) { \ |
| 121 | case 1: \ |
| 122 | __put_user_asm(x, ptr, retval, "stb"); \ |
| 123 | break; \ |
| 124 | case 2: \ |
| 125 | __put_user_asm(x, ptr, retval, "sth"); \ |
| 126 | break; \ |
| 127 | case 4: \ |
| 128 | __put_user_asm(x, ptr, retval, "stw"); \ |
| 129 | break; \ |
| 130 | case 8: \ |
| 131 | __put_user_asm2(x, ptr, retval); \ |
| 132 | break; \ |
| 133 | default: \ |
| 134 | __put_user_bad(); \ |
| 135 | } \ |
| 136 | } while (0) |
| 137 | |
| 138 | /* |
| 139 | * We don't tell gcc that we are accessing memory, but this is OK |
| 140 | * because we do not write to any memory gcc knows about, so there |
| 141 | * are no aliasing issues. |
| 142 | */ |
| 143 | #define __put_user_asm(x, addr, err, op) \ |
| 144 | __asm__ __volatile__( \ |
| 145 | "1: "op" %1,0(%2)\n" \ |
| 146 | "2:\n" \ |
| 147 | ".section .fixup,\"ax\"\n" \ |
| 148 | "3: li %0,%3\n" \ |
| 149 | " b 2b\n" \ |
| 150 | ".previous\n" \ |
| 151 | ".section __ex_table,\"a\"\n" \ |
| 152 | " .align 2\n" \ |
| 153 | " .long 1b,3b\n" \ |
| 154 | ".previous" \ |
| 155 | : "=r" (err) \ |
| 156 | : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) |
| 157 | |
| 158 | #define __put_user_asm2(x, addr, err) \ |
| 159 | __asm__ __volatile__( \ |
| 160 | "1: stw %1,0(%2)\n" \ |
| 161 | "2: stw %1+1,4(%2)\n" \ |
| 162 | "3:\n" \ |
| 163 | ".section .fixup,\"ax\"\n" \ |
| 164 | "4: li %0,%3\n" \ |
| 165 | " b 3b\n" \ |
| 166 | ".previous\n" \ |
| 167 | ".section __ex_table,\"a\"\n" \ |
| 168 | " .align 2\n" \ |
| 169 | " .long 1b,4b\n" \ |
| 170 | " .long 2b,4b\n" \ |
| 171 | ".previous" \ |
| 172 | : "=r" (err) \ |
| 173 | : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) |
| 174 | |
| 175 | #define __get_user_nocheck(x, ptr, size) \ |
| 176 | ({ \ |
| 177 | long __gu_err; \ |
| 178 | unsigned long __gu_val; \ |
| 179 | __chk_user_ptr(ptr); \ |
| 180 | __get_user_size(__gu_val, (ptr), (size), __gu_err); \ |
| 181 | (x) = (__typeof__(*(ptr)))__gu_val; \ |
| 182 | __gu_err; \ |
| 183 | }) |
| 184 | |
| 185 | #define __get_user64_nocheck(x, ptr, size) \ |
| 186 | ({ \ |
| 187 | long __gu_err; \ |
| 188 | long long __gu_val; \ |
| 189 | __chk_user_ptr(ptr); \ |
| 190 | __get_user_size64(__gu_val, (ptr), (size), __gu_err); \ |
| 191 | (x) = (__typeof__(*(ptr)))__gu_val; \ |
| 192 | __gu_err; \ |
| 193 | }) |
| 194 | |
| 195 | #define __get_user_check(x, ptr, size) \ |
| 196 | ({ \ |
| 197 | long __gu_err = -EFAULT; \ |
| 198 | unsigned long __gu_val = 0; \ |
| 199 | const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ |
| 200 | if (access_ok(VERIFY_READ, __gu_addr, (size))) \ |
| 201 | __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ |
| 202 | (x) = (__typeof__(*(ptr)))__gu_val; \ |
| 203 | __gu_err; \ |
| 204 | }) |
| 205 | |
| 206 | #define __get_user64_check(x, ptr, size) \ |
| 207 | ({ \ |
| 208 | long __gu_err = -EFAULT; \ |
| 209 | long long __gu_val = 0; \ |
| 210 | const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ |
| 211 | if (access_ok(VERIFY_READ, __gu_addr, (size))) \ |
| 212 | __get_user_size64(__gu_val, __gu_addr, (size), __gu_err); \ |
| 213 | (x) = (__typeof__(*(ptr)))__gu_val; \ |
| 214 | __gu_err; \ |
| 215 | }) |
| 216 | |
| 217 | extern long __get_user_bad(void); |
| 218 | |
| 219 | #define __get_user_size(x, ptr, size, retval) \ |
| 220 | do { \ |
| 221 | retval = 0; \ |
| 222 | switch (size) { \ |
| 223 | case 1: \ |
| 224 | __get_user_asm(x, ptr, retval, "lbz"); \ |
| 225 | break; \ |
| 226 | case 2: \ |
| 227 | __get_user_asm(x, ptr, retval, "lhz"); \ |
| 228 | break; \ |
| 229 | case 4: \ |
| 230 | __get_user_asm(x, ptr, retval, "lwz"); \ |
| 231 | break; \ |
| 232 | default: \ |
| 233 | x = __get_user_bad(); \ |
| 234 | } \ |
| 235 | } while (0) |
| 236 | |
| 237 | #define __get_user_size64(x, ptr, size, retval) \ |
| 238 | do { \ |
| 239 | retval = 0; \ |
| 240 | switch (size) { \ |
| 241 | case 1: \ |
| 242 | __get_user_asm(x, ptr, retval, "lbz"); \ |
| 243 | break; \ |
| 244 | case 2: \ |
| 245 | __get_user_asm(x, ptr, retval, "lhz"); \ |
| 246 | break; \ |
| 247 | case 4: \ |
| 248 | __get_user_asm(x, ptr, retval, "lwz"); \ |
| 249 | break; \ |
| 250 | case 8: \ |
| 251 | __get_user_asm2(x, ptr, retval); \ |
| 252 | break; \ |
| 253 | default: \ |
| 254 | x = __get_user_bad(); \ |
| 255 | } \ |
| 256 | } while (0) |
| 257 | |
| 258 | #define __get_user_asm(x, addr, err, op) \ |
| 259 | __asm__ __volatile__( \ |
| 260 | "1: "op" %1,0(%2)\n" \ |
| 261 | "2:\n" \ |
| 262 | ".section .fixup,\"ax\"\n" \ |
| 263 | "3: li %0,%3\n" \ |
| 264 | " li %1,0\n" \ |
| 265 | " b 2b\n" \ |
| 266 | ".previous\n" \ |
| 267 | ".section __ex_table,\"a\"\n" \ |
| 268 | " .align 2\n" \ |
| 269 | " .long 1b,3b\n" \ |
| 270 | ".previous" \ |
| 271 | : "=r"(err), "=r"(x) \ |
| 272 | : "b"(addr), "i"(-EFAULT), "0"(err)) |
| 273 | |
| 274 | #define __get_user_asm2(x, addr, err) \ |
| 275 | __asm__ __volatile__( \ |
| 276 | "1: lwz %1,0(%2)\n" \ |
| 277 | "2: lwz %1+1,4(%2)\n" \ |
| 278 | "3:\n" \ |
| 279 | ".section .fixup,\"ax\"\n" \ |
| 280 | "4: li %0,%3\n" \ |
| 281 | " li %1,0\n" \ |
| 282 | " li %1+1,0\n" \ |
| 283 | " b 3b\n" \ |
| 284 | ".previous\n" \ |
| 285 | ".section __ex_table,\"a\"\n" \ |
| 286 | " .align 2\n" \ |
| 287 | " .long 1b,4b\n" \ |
| 288 | " .long 2b,4b\n" \ |
| 289 | ".previous" \ |
| 290 | : "=r"(err), "=&r"(x) \ |
| 291 | : "b"(addr), "i"(-EFAULT), "0"(err)) |
| 292 | |
| 293 | /* more complex routines */ |
| 294 | |
| 295 | extern int __copy_tofrom_user(void __user *to, const void __user *from, |
| 296 | unsigned long size); |
| 297 | |
| 298 | extern inline unsigned long |
| 299 | copy_from_user(void *to, const void __user *from, unsigned long n) |
| 300 | { |
| 301 | unsigned long over; |
| 302 | |
| 303 | if (access_ok(VERIFY_READ, from, n)) |
| 304 | return __copy_tofrom_user((__force void __user *)to, from, n); |
| 305 | if ((unsigned long)from < TASK_SIZE) { |
| 306 | over = (unsigned long)from + n - TASK_SIZE; |
| 307 | return __copy_tofrom_user((__force void __user *)to, from, n - over) + over; |
| 308 | } |
| 309 | return n; |
| 310 | } |
| 311 | |
| 312 | extern inline unsigned long |
| 313 | copy_to_user(void __user *to, const void *from, unsigned long n) |
| 314 | { |
| 315 | unsigned long over; |
| 316 | |
| 317 | if (access_ok(VERIFY_WRITE, to, n)) |
| 318 | return __copy_tofrom_user(to, (__force void __user *) from, n); |
| 319 | if ((unsigned long)to < TASK_SIZE) { |
| 320 | over = (unsigned long)to + n - TASK_SIZE; |
| 321 | return __copy_tofrom_user(to, (__force void __user *) from, n - over) + over; |
| 322 | } |
| 323 | return n; |
| 324 | } |
| 325 | |
| 326 | static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long size) |
| 327 | { |
| 328 | return __copy_tofrom_user((__force void __user *)to, from, size); |
| 329 | } |
| 330 | |
| 331 | static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long size) |
| 332 | { |
| 333 | return __copy_tofrom_user(to, (__force void __user *)from, size); |
| 334 | } |
| 335 | |
| 336 | #define __copy_to_user_inatomic __copy_to_user |
| 337 | #define __copy_from_user_inatomic __copy_from_user |
| 338 | |
| 339 | extern unsigned long __clear_user(void __user *addr, unsigned long size); |
| 340 | |
| 341 | extern inline unsigned long |
| 342 | clear_user(void __user *addr, unsigned long size) |
| 343 | { |
| 344 | if (access_ok(VERIFY_WRITE, addr, size)) |
| 345 | return __clear_user(addr, size); |
| 346 | if ((unsigned long)addr < TASK_SIZE) { |
| 347 | unsigned long over = (unsigned long)addr + size - TASK_SIZE; |
| 348 | return __clear_user(addr, size - over) + over; |
| 349 | } |
| 350 | return size; |
| 351 | } |
| 352 | |
| 353 | extern int __strncpy_from_user(char *dst, const char __user *src, long count); |
| 354 | |
| 355 | extern inline long |
| 356 | strncpy_from_user(char *dst, const char __user *src, long count) |
| 357 | { |
| 358 | if (access_ok(VERIFY_READ, src, 1)) |
| 359 | return __strncpy_from_user(dst, src, count); |
| 360 | return -EFAULT; |
| 361 | } |
| 362 | |
| 363 | /* |
| 364 | * Return the size of a string (including the ending 0) |
| 365 | * |
| 366 | * Return 0 for error |
| 367 | */ |
| 368 | |
| 369 | extern int __strnlen_user(const char __user *str, long len, unsigned long top); |
| 370 | |
| 371 | /* |
| 372 | * Returns the length of the string at str (including the null byte), |
| 373 | * or 0 if we hit a page we can't access, |
| 374 | * or something > len if we didn't find a null byte. |
| 375 | * |
| 376 | * The `top' parameter to __strnlen_user is to make sure that |
| 377 | * we can never overflow from the user area into kernel space. |
| 378 | */ |
| 379 | extern __inline__ int strnlen_user(const char __user *str, long len) |
| 380 | { |
| 381 | unsigned long top = current->thread.fs.seg; |
| 382 | |
| 383 | if ((unsigned long)str > top) |
| 384 | return 0; |
| 385 | return __strnlen_user(str, len, top); |
| 386 | } |
| 387 | |
| 388 | #define strlen_user(str) strnlen_user((str), 0x7ffffffe) |
| 389 | |
| 390 | #endif /* __ASSEMBLY__ */ |
| 391 | |
| 392 | #endif /* _PPC_UACCESS_H */ |
| 393 | #endif /* __KERNEL__ */ |