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