1#ifndef _ARCH_POWERPC_UACCESS_H 2#define _ARCH_POWERPC_UACCESS_H 3 4#ifdef __KERNEL__ 5#ifndef __ASSEMBLY__ 6 7#include <linux/sched.h> 8#include <linux/errno.h> 9#include <asm/processor.h> 10#include <asm/page.h> 11 12#define VERIFY_READ 0 13#define VERIFY_WRITE 1 14 15/* 16 * The fs value determines whether argument validity checking should be 17 * performed or not. If get_fs() == USER_DS, checking is performed, with 18 * get_fs() == KERNEL_DS, checking is bypassed. 19 * 20 * For historical reasons, these macros are grossly misnamed. 21 * 22 * The fs/ds values are now the highest legal address in the "segment". 23 * This simplifies the checking in the routines below. 24 */ 25 26#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 27 28#define KERNEL_DS MAKE_MM_SEG(~0UL) 29#ifdef __powerpc64__ 30/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ 31#define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1) 32#else 33#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 34#endif 35 36#define get_ds() (KERNEL_DS) 37#define get_fs() (current->thread.fs) 38#define set_fs(val) (current->thread.fs = (val)) 39 40#define segment_eq(a, b) ((a).seg == (b).seg) 41 42#ifdef __powerpc64__ 43/* 44 * This check is sufficient because there is a large enough 45 * gap between user addresses and the kernel addresses 46 */ 47#define __access_ok(addr, size, segment) \ 48 (((addr) <= (segment).seg) && ((size) <= (segment).seg)) 49 50#else 51 52#define __access_ok(addr, size, segment) \ 53 (((addr) <= (segment).seg) && \ 54 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) 55 56#endif 57 58#define access_ok(type, addr, size) \ 59 (__chk_user_ptr(addr), \ 60 __access_ok((__force unsigned long)(addr), (size), get_fs())) 61 62/* 63 * The exception table consists of pairs of addresses: the first is the 64 * address of an instruction that is allowed to fault, and the second is 65 * the address at which the program should continue. No registers are 66 * modified, so it is entirely up to the continuation code to figure out 67 * what to do. 68 * 69 * All the routines below use bits of fixup code that are out of line 70 * with the main instruction path. This means when everything is well, 71 * we don't even have to jump over them. Further, they do not intrude 72 * on our cache or tlb entries. 73 */ 74 75struct exception_table_entry { 76 unsigned long insn; 77 unsigned long fixup; 78}; 79 80/* 81 * These are the main single-value transfer routines. They automatically 82 * use the right size if we just have the right pointer type. 83 * 84 * This gets kind of ugly. We want to return _two_ values in "get_user()" 85 * and yet we don't want to do any pointers, because that is too much 86 * of a performance impact. Thus we have a few rather ugly macros here, 87 * and hide all the ugliness from the user. 88 * 89 * The "__xxx" versions of the user access functions are versions that 90 * do not verify the address space, that must have been done previously 91 * with a separate "access_ok()" call (this is used when we do multiple 92 * accesses to the same area of user memory). 93 * 94 * As we use the same address space for kernel and user data on the 95 * PowerPC, we can just do these as direct assignments. (Of course, the 96 * exception handling means that it's no longer "just"...) 97 * 98 * The "user64" versions of the user access functions are versions that 99 * allow access of 64-bit data. The "get_user" functions do not 100 * properly handle 64-bit data because the value gets down cast to a long. 101 * The "put_user" functions already handle 64-bit data properly but we add 102 * "user64" versions for completeness 103 */ 104#define get_user(x, ptr) \ 105 __get_user_check((x), (ptr), sizeof(*(ptr))) 106#define put_user(x, ptr) \ 107 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 108 109#define __get_user(x, ptr) \ 110 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 111#define __put_user(x, ptr) \ 112 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 113 114#ifndef __powerpc64__ 115#define __get_user64(x, ptr) \ 116 __get_user64_nocheck((x), (ptr), sizeof(*(ptr))) 117#define __put_user64(x, ptr) __put_user(x, ptr) 118#endif 119 120#define __get_user_inatomic(x, ptr) \ 121 __get_user_nosleep((x), (ptr), sizeof(*(ptr))) 122#define __put_user_inatomic(x, ptr) \ 123 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 124 125#define __get_user_unaligned __get_user 126#define __put_user_unaligned __put_user 127 128extern long __put_user_bad(void); 129 130/* 131 * We don't tell gcc that we are accessing memory, but this is OK 132 * because we do not write to any memory gcc knows about, so there 133 * are no aliasing issues. 134 */ 135#define __put_user_asm(x, addr, err, op) \ 136 __asm__ __volatile__( \ 137 "1: " op " %1,0(%2) # put_user\n" \ 138 "2:\n" \ 139 ".section .fixup,\"ax\"\n" \ 140 "3: li %0,%3\n" \ 141 " b 2b\n" \ 142 ".previous\n" \ 143 ".section __ex_table,\"a\"\n" \ 144 " .balign %5\n" \ 145 PPC_LONG "1b,3b\n" \ 146 ".previous" \ 147 : "=r" (err) \ 148 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\ 149 "i"(sizeof(unsigned long))) 150 151#ifdef __powerpc64__ 152#define __put_user_asm2(x, ptr, retval) \ 153 __put_user_asm(x, ptr, retval, "std") 154#else /* __powerpc64__ */ 155#define __put_user_asm2(x, addr, err) \ 156 __asm__ __volatile__( \ 157 "1: stw %1,0(%2)\n" \ 158 "2: stw %1+1,4(%2)\n" \ 159 "3:\n" \ 160 ".section .fixup,\"ax\"\n" \ 161 "4: li %0,%3\n" \ 162 " b 3b\n" \ 163 ".previous\n" \ 164 ".section __ex_table,\"a\"\n" \ 165 " .balign %5\n" \ 166 PPC_LONG "1b,4b\n" \ 167 PPC_LONG "2b,4b\n" \ 168 ".previous" \ 169 : "=r" (err) \ 170 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\ 171 "i"(sizeof(unsigned long))) 172#endif /* __powerpc64__ */ 173 174#define __put_user_size(x, ptr, size, retval) \ 175do { \ 176 retval = 0; \ 177 switch (size) { \ 178 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ 179 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ 180 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ 181 case 8: __put_user_asm2(x, ptr, retval); break; \ 182 default: __put_user_bad(); \ 183 } \ 184} while (0) 185 186#define __put_user_nocheck(x, ptr, size) \ 187({ \ 188 long __pu_err; \ 189 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 190 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 191 might_sleep(); \ 192 __chk_user_ptr(ptr); \ 193 __put_user_size((x), __pu_addr, (size), __pu_err); \ 194 __pu_err; \ 195}) 196 197#define __put_user_check(x, ptr, size) \ 198({ \ 199 long __pu_err = -EFAULT; \ 200 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 201 might_sleep(); \ 202 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ 203 __put_user_size((x), __pu_addr, (size), __pu_err); \ 204 __pu_err; \ 205}) 206 207#define __put_user_nosleep(x, ptr, size) \ 208({ \ 209 long __pu_err; \ 210 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 211 __chk_user_ptr(ptr); \ 212 __put_user_size((x), __pu_addr, (size), __pu_err); \ 213 __pu_err; \ 214}) 215 216 217extern long __get_user_bad(void); 218 219#define __get_user_asm(x, addr, err, op) \ 220 __asm__ __volatile__( \ 221 "1: "op" %1,0(%2) # get_user\n" \ 222 "2:\n" \ 223 ".section .fixup,\"ax\"\n" \ 224 "3: li %0,%3\n" \ 225 " li %1,0\n" \ 226 " b 2b\n" \ 227 ".previous\n" \ 228 ".section __ex_table,\"a\"\n" \ 229 " .balign %5\n" \ 230 PPC_LONG "1b,3b\n" \ 231 ".previous" \ 232 : "=r" (err), "=r" (x) \ 233 : "b" (addr), "i" (-EFAULT), "0" (err), \ 234 "i"(sizeof(unsigned long))) 235 236#ifdef __powerpc64__ 237#define __get_user_asm2(x, addr, err) \ 238 __get_user_asm(x, addr, err, "ld") 239#else /* __powerpc64__ */ 240#define __get_user_asm2(x, addr, err) \ 241 __asm__ __volatile__( \ 242 "1: lwz %1,0(%2)\n" \ 243 "2: lwz %1+1,4(%2)\n" \ 244 "3:\n" \ 245 ".section .fixup,\"ax\"\n" \ 246 "4: li %0,%3\n" \ 247 " li %1,0\n" \ 248 " li %1+1,0\n" \ 249 " b 3b\n" \ 250 ".previous\n" \ 251 ".section __ex_table,\"a\"\n" \ 252 " .balign %5\n" \ 253 PPC_LONG "1b,4b\n" \ 254 PPC_LONG "2b,4b\n" \ 255 ".previous" \ 256 : "=r" (err), "=&r" (x) \ 257 : "b" (addr), "i" (-EFAULT), "0" (err), \ 258 "i"(sizeof(unsigned long))) 259#endif /* __powerpc64__ */ 260 261#define __get_user_size(x, ptr, size, retval) \ 262do { \ 263 retval = 0; \ 264 __chk_user_ptr(ptr); \ 265 if (size > sizeof(x)) \ 266 (x) = __get_user_bad(); \ 267 switch (size) { \ 268 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ 269 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ 270 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ 271 case 8: __get_user_asm2(x, ptr, retval); break; \ 272 default: (x) = __get_user_bad(); \ 273 } \ 274} while (0) 275 276#define __get_user_nocheck(x, ptr, size) \ 277({ \ 278 long __gu_err; \ 279 unsigned long __gu_val; \ 280 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 281 __chk_user_ptr(ptr); \ 282 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 283 might_sleep(); \ 284 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 285 (x) = (__typeof__(*(ptr)))__gu_val; \ 286 __gu_err; \ 287}) 288 289#ifndef __powerpc64__ 290#define __get_user64_nocheck(x, ptr, size) \ 291({ \ 292 long __gu_err; \ 293 long long __gu_val; \ 294 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 295 __chk_user_ptr(ptr); \ 296 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 297 might_sleep(); \ 298 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 299 (x) = (__typeof__(*(ptr)))__gu_val; \ 300 __gu_err; \ 301}) 302#endif /* __powerpc64__ */ 303 304#define __get_user_check(x, ptr, size) \ 305({ \ 306 long __gu_err = -EFAULT; \ 307 unsigned long __gu_val = 0; \ 308 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 309 might_sleep(); \ 310 if (access_ok(VERIFY_READ, __gu_addr, (size))) \ 311 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 312 (x) = (__typeof__(*(ptr)))__gu_val; \ 313 __gu_err; \ 314}) 315 316#define __get_user_nosleep(x, ptr, size) \ 317({ \ 318 long __gu_err; \ 319 unsigned long __gu_val; \ 320 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 321 __chk_user_ptr(ptr); \ 322 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 323 (x) = (__typeof__(*(ptr)))__gu_val; \ 324 __gu_err; \ 325}) 326 327 328/* more complex routines */ 329 330extern unsigned long __copy_tofrom_user(void __user *to, 331 const void __user *from, unsigned long size); 332 333#ifndef __powerpc64__ 334 335static inline unsigned long copy_from_user(void *to, 336 const void __user *from, unsigned long n) 337{ 338 unsigned long over; 339 340 if (access_ok(VERIFY_READ, from, n)) 341 return __copy_tofrom_user((__force void __user *)to, from, n); 342 if ((unsigned long)from < TASK_SIZE) { 343 over = (unsigned long)from + n - TASK_SIZE; 344 return __copy_tofrom_user((__force void __user *)to, from, 345 n - over) + over; 346 } 347 return n; 348} 349 350static inline unsigned long copy_to_user(void __user *to, 351 const void *from, unsigned long n) 352{ 353 unsigned long over; 354 355 if (access_ok(VERIFY_WRITE, to, n)) 356 return __copy_tofrom_user(to, (__force void __user *)from, n); 357 if ((unsigned long)to < TASK_SIZE) { 358 over = (unsigned long)to + n - TASK_SIZE; 359 return __copy_tofrom_user(to, (__force void __user *)from, 360 n - over) + over; 361 } 362 return n; 363} 364 365#else /* __powerpc64__ */ 366 367#define __copy_in_user(to, from, size) \ 368 __copy_tofrom_user((to), (from), (size)) 369 370extern unsigned long copy_from_user(void *to, const void __user *from, 371 unsigned long n); 372extern unsigned long copy_to_user(void __user *to, const void *from, 373 unsigned long n); 374extern unsigned long copy_in_user(void __user *to, const void __user *from, 375 unsigned long n); 376 377#endif /* __powerpc64__ */ 378 379static inline unsigned long __copy_from_user_inatomic(void *to, 380 const void __user *from, unsigned long n) 381{ 382 if (__builtin_constant_p(n) && (n <= 8)) { 383 unsigned long ret; 384 385 switch (n) { 386 case 1: 387 __get_user_size(*(u8 *)to, from, 1, ret); 388 break; 389 case 2: 390 __get_user_size(*(u16 *)to, from, 2, ret); 391 break; 392 case 4: 393 __get_user_size(*(u32 *)to, from, 4, ret); 394 break; 395 case 8: 396 __get_user_size(*(u64 *)to, from, 8, ret); 397 break; 398 } 399 if (ret == 0) 400 return 0; 401 } 402 return __copy_tofrom_user((__force void __user *)to, from, n); 403} 404 405static inline unsigned long __copy_to_user_inatomic(void __user *to, 406 const void *from, unsigned long n) 407{ 408 if (__builtin_constant_p(n) && (n <= 8)) { 409 unsigned long ret; 410 411 switch (n) { 412 case 1: 413 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); 414 break; 415 case 2: 416 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); 417 break; 418 case 4: 419 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); 420 break; 421 case 8: 422 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); 423 break; 424 } 425 if (ret == 0) 426 return 0; 427 } 428 return __copy_tofrom_user(to, (__force const void __user *)from, n); 429} 430 431static inline unsigned long __copy_from_user(void *to, 432 const void __user *from, unsigned long size) 433{ 434 might_sleep(); 435 return __copy_from_user_inatomic(to, from, size); 436} 437 438static inline unsigned long __copy_to_user(void __user *to, 439 const void *from, unsigned long size) 440{ 441 might_sleep(); 442 return __copy_to_user_inatomic(to, from, size); 443} 444 445extern unsigned long __clear_user(void __user *addr, unsigned long size); 446 447static inline unsigned long clear_user(void __user *addr, unsigned long size) 448{ 449 might_sleep(); 450 if (likely(access_ok(VERIFY_WRITE, addr, size))) 451 return __clear_user(addr, size); 452 if ((unsigned long)addr < TASK_SIZE) { 453 unsigned long over = (unsigned long)addr + size - TASK_SIZE; 454 return __clear_user(addr, size - over) + over; 455 } 456 return size; 457} 458 459extern int __strncpy_from_user(char *dst, const char __user *src, long count); 460 461static inline long strncpy_from_user(char *dst, const char __user *src, 462 long count) 463{ 464 might_sleep(); 465 if (likely(access_ok(VERIFY_READ, src, 1))) 466 return __strncpy_from_user(dst, src, count); 467 return -EFAULT; 468} 469 470/* 471 * Return the size of a string (including the ending 0) 472 * 473 * Return 0 for error 474 */ 475extern int __strnlen_user(const char __user *str, long len, unsigned long top); 476 477/* 478 * Returns the length of the string at str (including the null byte), 479 * or 0 if we hit a page we can't access, 480 * or something > len if we didn't find a null byte. 481 * 482 * The `top' parameter to __strnlen_user is to make sure that 483 * we can never overflow from the user area into kernel space. 484 */ 485static inline int strnlen_user(const char __user *str, long len) 486{ 487 unsigned long top = current->thread.fs.seg; 488 489 if ((unsigned long)str > top) 490 return 0; 491 return __strnlen_user(str, len, top); 492} 493 494#define strlen_user(str) strnlen_user((str), 0x7ffffffe) 495 496#endif /* __ASSEMBLY__ */ 497#endif /* __KERNEL__ */ 498 499#endif /* _ARCH_POWERPC_UACCESS_H */ 500