1 /* 2 * linux/kernel/compat.c 3 * 4 * Kernel compatibililty routines for e.g. 32 bit syscall support 5 * on 64 bit kernels. 6 * 7 * Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/linkage.h> 15 #include <linux/compat.h> 16 #include <linux/errno.h> 17 #include <linux/time.h> 18 #include <linux/signal.h> 19 #include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */ 20 #include <linux/syscalls.h> 21 #include <linux/unistd.h> 22 #include <linux/security.h> 23 #include <linux/timex.h> 24 #include <linux/export.h> 25 #include <linux/migrate.h> 26 #include <linux/posix-timers.h> 27 #include <linux/times.h> 28 #include <linux/ptrace.h> 29 #include <linux/gfp.h> 30 31 #include <linux/uaccess.h> 32 33 int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp) 34 { 35 struct compat_timex tx32; 36 37 if (copy_from_user(&tx32, utp, sizeof(struct compat_timex))) 38 return -EFAULT; 39 40 txc->modes = tx32.modes; 41 txc->offset = tx32.offset; 42 txc->freq = tx32.freq; 43 txc->maxerror = tx32.maxerror; 44 txc->esterror = tx32.esterror; 45 txc->status = tx32.status; 46 txc->constant = tx32.constant; 47 txc->precision = tx32.precision; 48 txc->tolerance = tx32.tolerance; 49 txc->time.tv_sec = tx32.time.tv_sec; 50 txc->time.tv_usec = tx32.time.tv_usec; 51 txc->tick = tx32.tick; 52 txc->ppsfreq = tx32.ppsfreq; 53 txc->jitter = tx32.jitter; 54 txc->shift = tx32.shift; 55 txc->stabil = tx32.stabil; 56 txc->jitcnt = tx32.jitcnt; 57 txc->calcnt = tx32.calcnt; 58 txc->errcnt = tx32.errcnt; 59 txc->stbcnt = tx32.stbcnt; 60 61 return 0; 62 } 63 64 int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc) 65 { 66 struct compat_timex tx32; 67 68 memset(&tx32, 0, sizeof(struct compat_timex)); 69 tx32.modes = txc->modes; 70 tx32.offset = txc->offset; 71 tx32.freq = txc->freq; 72 tx32.maxerror = txc->maxerror; 73 tx32.esterror = txc->esterror; 74 tx32.status = txc->status; 75 tx32.constant = txc->constant; 76 tx32.precision = txc->precision; 77 tx32.tolerance = txc->tolerance; 78 tx32.time.tv_sec = txc->time.tv_sec; 79 tx32.time.tv_usec = txc->time.tv_usec; 80 tx32.tick = txc->tick; 81 tx32.ppsfreq = txc->ppsfreq; 82 tx32.jitter = txc->jitter; 83 tx32.shift = txc->shift; 84 tx32.stabil = txc->stabil; 85 tx32.jitcnt = txc->jitcnt; 86 tx32.calcnt = txc->calcnt; 87 tx32.errcnt = txc->errcnt; 88 tx32.stbcnt = txc->stbcnt; 89 tx32.tai = txc->tai; 90 if (copy_to_user(utp, &tx32, sizeof(struct compat_timex))) 91 return -EFAULT; 92 return 0; 93 } 94 95 static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv) 96 { 97 return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) || 98 __get_user(tv->tv_sec, &ctv->tv_sec) || 99 __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; 100 } 101 102 static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv) 103 { 104 return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) || 105 __put_user(tv->tv_sec, &ctv->tv_sec) || 106 __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; 107 } 108 109 static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts) 110 { 111 return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) || 112 __get_user(ts->tv_sec, &cts->tv_sec) || 113 __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; 114 } 115 116 static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts) 117 { 118 return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) || 119 __put_user(ts->tv_sec, &cts->tv_sec) || 120 __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; 121 } 122 123 static int __compat_get_timespec64(struct timespec64 *ts64, 124 const struct compat_timespec __user *cts) 125 { 126 struct compat_timespec ts; 127 int ret; 128 129 ret = copy_from_user(&ts, cts, sizeof(ts)); 130 if (ret) 131 return -EFAULT; 132 133 ts64->tv_sec = ts.tv_sec; 134 ts64->tv_nsec = ts.tv_nsec; 135 136 return 0; 137 } 138 139 static int __compat_put_timespec64(const struct timespec64 *ts64, 140 struct compat_timespec __user *cts) 141 { 142 struct compat_timespec ts = { 143 .tv_sec = ts64->tv_sec, 144 .tv_nsec = ts64->tv_nsec 145 }; 146 return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0; 147 } 148 149 int compat_get_timespec64(struct timespec64 *ts, const void __user *uts) 150 { 151 if (COMPAT_USE_64BIT_TIME) 152 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 153 else 154 return __compat_get_timespec64(ts, uts); 155 } 156 EXPORT_SYMBOL_GPL(compat_get_timespec64); 157 158 int compat_put_timespec64(const struct timespec64 *ts, void __user *uts) 159 { 160 if (COMPAT_USE_64BIT_TIME) 161 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 162 else 163 return __compat_put_timespec64(ts, uts); 164 } 165 EXPORT_SYMBOL_GPL(compat_put_timespec64); 166 167 int compat_get_timeval(struct timeval *tv, const void __user *utv) 168 { 169 if (COMPAT_USE_64BIT_TIME) 170 return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0; 171 else 172 return __compat_get_timeval(tv, utv); 173 } 174 EXPORT_SYMBOL_GPL(compat_get_timeval); 175 176 int compat_put_timeval(const struct timeval *tv, void __user *utv) 177 { 178 if (COMPAT_USE_64BIT_TIME) 179 return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0; 180 else 181 return __compat_put_timeval(tv, utv); 182 } 183 EXPORT_SYMBOL_GPL(compat_put_timeval); 184 185 int compat_get_timespec(struct timespec *ts, const void __user *uts) 186 { 187 if (COMPAT_USE_64BIT_TIME) 188 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 189 else 190 return __compat_get_timespec(ts, uts); 191 } 192 EXPORT_SYMBOL_GPL(compat_get_timespec); 193 194 int compat_put_timespec(const struct timespec *ts, void __user *uts) 195 { 196 if (COMPAT_USE_64BIT_TIME) 197 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 198 else 199 return __compat_put_timespec(ts, uts); 200 } 201 EXPORT_SYMBOL_GPL(compat_put_timespec); 202 203 int compat_convert_timespec(struct timespec __user **kts, 204 const void __user *cts) 205 { 206 struct timespec ts; 207 struct timespec __user *uts; 208 209 if (!cts || COMPAT_USE_64BIT_TIME) { 210 *kts = (struct timespec __user *)cts; 211 return 0; 212 } 213 214 uts = compat_alloc_user_space(sizeof(ts)); 215 if (!uts) 216 return -EFAULT; 217 if (compat_get_timespec(&ts, cts)) 218 return -EFAULT; 219 if (copy_to_user(uts, &ts, sizeof(ts))) 220 return -EFAULT; 221 222 *kts = uts; 223 return 0; 224 } 225 226 int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i) 227 { 228 struct compat_itimerval v32; 229 230 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval))) 231 return -EFAULT; 232 o->it_interval.tv_sec = v32.it_interval.tv_sec; 233 o->it_interval.tv_usec = v32.it_interval.tv_usec; 234 o->it_value.tv_sec = v32.it_value.tv_sec; 235 o->it_value.tv_usec = v32.it_value.tv_usec; 236 return 0; 237 } 238 239 int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i) 240 { 241 struct compat_itimerval v32; 242 243 v32.it_interval.tv_sec = i->it_interval.tv_sec; 244 v32.it_interval.tv_usec = i->it_interval.tv_usec; 245 v32.it_value.tv_sec = i->it_value.tv_sec; 246 v32.it_value.tv_usec = i->it_value.tv_usec; 247 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0; 248 } 249 250 #ifdef __ARCH_WANT_SYS_SIGPROCMASK 251 252 /* 253 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the 254 * blocked set of signals to the supplied signal set 255 */ 256 static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set) 257 { 258 memcpy(blocked->sig, &set, sizeof(set)); 259 } 260 261 COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how, 262 compat_old_sigset_t __user *, nset, 263 compat_old_sigset_t __user *, oset) 264 { 265 old_sigset_t old_set, new_set; 266 sigset_t new_blocked; 267 268 old_set = current->blocked.sig[0]; 269 270 if (nset) { 271 if (get_user(new_set, nset)) 272 return -EFAULT; 273 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); 274 275 new_blocked = current->blocked; 276 277 switch (how) { 278 case SIG_BLOCK: 279 sigaddsetmask(&new_blocked, new_set); 280 break; 281 case SIG_UNBLOCK: 282 sigdelsetmask(&new_blocked, new_set); 283 break; 284 case SIG_SETMASK: 285 compat_sig_setmask(&new_blocked, new_set); 286 break; 287 default: 288 return -EINVAL; 289 } 290 291 set_current_blocked(&new_blocked); 292 } 293 294 if (oset) { 295 if (put_user(old_set, oset)) 296 return -EFAULT; 297 } 298 299 return 0; 300 } 301 302 #endif 303 304 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru) 305 { 306 struct compat_rusage r32; 307 memset(&r32, 0, sizeof(r32)); 308 r32.ru_utime.tv_sec = r->ru_utime.tv_sec; 309 r32.ru_utime.tv_usec = r->ru_utime.tv_usec; 310 r32.ru_stime.tv_sec = r->ru_stime.tv_sec; 311 r32.ru_stime.tv_usec = r->ru_stime.tv_usec; 312 r32.ru_maxrss = r->ru_maxrss; 313 r32.ru_ixrss = r->ru_ixrss; 314 r32.ru_idrss = r->ru_idrss; 315 r32.ru_isrss = r->ru_isrss; 316 r32.ru_minflt = r->ru_minflt; 317 r32.ru_majflt = r->ru_majflt; 318 r32.ru_nswap = r->ru_nswap; 319 r32.ru_inblock = r->ru_inblock; 320 r32.ru_oublock = r->ru_oublock; 321 r32.ru_msgsnd = r->ru_msgsnd; 322 r32.ru_msgrcv = r->ru_msgrcv; 323 r32.ru_nsignals = r->ru_nsignals; 324 r32.ru_nvcsw = r->ru_nvcsw; 325 r32.ru_nivcsw = r->ru_nivcsw; 326 if (copy_to_user(ru, &r32, sizeof(r32))) 327 return -EFAULT; 328 return 0; 329 } 330 331 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr, 332 unsigned len, struct cpumask *new_mask) 333 { 334 unsigned long *k; 335 336 if (len < cpumask_size()) 337 memset(new_mask, 0, cpumask_size()); 338 else if (len > cpumask_size()) 339 len = cpumask_size(); 340 341 k = cpumask_bits(new_mask); 342 return compat_get_bitmap(k, user_mask_ptr, len * 8); 343 } 344 345 COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid, 346 unsigned int, len, 347 compat_ulong_t __user *, user_mask_ptr) 348 { 349 cpumask_var_t new_mask; 350 int retval; 351 352 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) 353 return -ENOMEM; 354 355 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask); 356 if (retval) 357 goto out; 358 359 retval = sched_setaffinity(pid, new_mask); 360 out: 361 free_cpumask_var(new_mask); 362 return retval; 363 } 364 365 COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len, 366 compat_ulong_t __user *, user_mask_ptr) 367 { 368 int ret; 369 cpumask_var_t mask; 370 371 if ((len * BITS_PER_BYTE) < nr_cpu_ids) 372 return -EINVAL; 373 if (len & (sizeof(compat_ulong_t)-1)) 374 return -EINVAL; 375 376 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 377 return -ENOMEM; 378 379 ret = sched_getaffinity(pid, mask); 380 if (ret == 0) { 381 size_t retlen = min_t(size_t, len, cpumask_size()); 382 383 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8)) 384 ret = -EFAULT; 385 else 386 ret = retlen; 387 } 388 free_cpumask_var(mask); 389 390 return ret; 391 } 392 393 int get_compat_itimerspec(struct itimerspec *dst, 394 const struct compat_itimerspec __user *src) 395 { 396 if (__compat_get_timespec(&dst->it_interval, &src->it_interval) || 397 __compat_get_timespec(&dst->it_value, &src->it_value)) 398 return -EFAULT; 399 return 0; 400 } 401 402 int put_compat_itimerspec(struct compat_itimerspec __user *dst, 403 const struct itimerspec *src) 404 { 405 if (__compat_put_timespec(&src->it_interval, &dst->it_interval) || 406 __compat_put_timespec(&src->it_value, &dst->it_value)) 407 return -EFAULT; 408 return 0; 409 } 410 411 int get_compat_itimerspec64(struct itimerspec64 *its, 412 const struct compat_itimerspec __user *uits) 413 { 414 415 if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) || 416 __compat_get_timespec64(&its->it_value, &uits->it_value)) 417 return -EFAULT; 418 return 0; 419 } 420 EXPORT_SYMBOL_GPL(get_compat_itimerspec64); 421 422 int put_compat_itimerspec64(const struct itimerspec64 *its, 423 struct compat_itimerspec __user *uits) 424 { 425 if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) || 426 __compat_put_timespec64(&its->it_value, &uits->it_value)) 427 return -EFAULT; 428 return 0; 429 } 430 EXPORT_SYMBOL_GPL(put_compat_itimerspec64); 431 432 /* 433 * We currently only need the following fields from the sigevent 434 * structure: sigev_value, sigev_signo, sig_notify and (sometimes 435 * sigev_notify_thread_id). The others are handled in user mode. 436 * We also assume that copying sigev_value.sival_int is sufficient 437 * to keep all the bits of sigev_value.sival_ptr intact. 438 */ 439 int get_compat_sigevent(struct sigevent *event, 440 const struct compat_sigevent __user *u_event) 441 { 442 memset(event, 0, sizeof(*event)); 443 return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) || 444 __get_user(event->sigev_value.sival_int, 445 &u_event->sigev_value.sival_int) || 446 __get_user(event->sigev_signo, &u_event->sigev_signo) || 447 __get_user(event->sigev_notify, &u_event->sigev_notify) || 448 __get_user(event->sigev_notify_thread_id, 449 &u_event->sigev_notify_thread_id)) 450 ? -EFAULT : 0; 451 } 452 453 long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, 454 unsigned long bitmap_size) 455 { 456 unsigned long nr_compat_longs; 457 458 /* align bitmap up to nearest compat_long_t boundary */ 459 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 460 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 461 462 if (!access_ok(VERIFY_READ, umask, bitmap_size / 8)) 463 return -EFAULT; 464 465 user_access_begin(); 466 while (nr_compat_longs > 1) { 467 compat_ulong_t l1, l2; 468 unsafe_get_user(l1, umask++, Efault); 469 unsafe_get_user(l2, umask++, Efault); 470 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1; 471 nr_compat_longs -= 2; 472 } 473 if (nr_compat_longs) 474 unsafe_get_user(*mask, umask++, Efault); 475 user_access_end(); 476 return 0; 477 478 Efault: 479 user_access_end(); 480 return -EFAULT; 481 } 482 483 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, 484 unsigned long bitmap_size) 485 { 486 unsigned long nr_compat_longs; 487 488 /* align bitmap up to nearest compat_long_t boundary */ 489 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 490 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 491 492 if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8)) 493 return -EFAULT; 494 495 user_access_begin(); 496 while (nr_compat_longs > 1) { 497 unsigned long m = *mask++; 498 unsafe_put_user((compat_ulong_t)m, umask++, Efault); 499 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault); 500 nr_compat_longs -= 2; 501 } 502 if (nr_compat_longs) 503 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault); 504 user_access_end(); 505 return 0; 506 Efault: 507 user_access_end(); 508 return -EFAULT; 509 } 510 511 void 512 sigset_from_compat(sigset_t *set, const compat_sigset_t *compat) 513 { 514 switch (_NSIG_WORDS) { 515 case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 ); 516 case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 ); 517 case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 ); 518 case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 ); 519 } 520 } 521 EXPORT_SYMBOL_GPL(sigset_from_compat); 522 523 void 524 sigset_to_compat(compat_sigset_t *compat, const sigset_t *set) 525 { 526 switch (_NSIG_WORDS) { 527 case 4: compat->sig[7] = (set->sig[3] >> 32); compat->sig[6] = set->sig[3]; 528 case 3: compat->sig[5] = (set->sig[2] >> 32); compat->sig[4] = set->sig[2]; 529 case 2: compat->sig[3] = (set->sig[1] >> 32); compat->sig[2] = set->sig[1]; 530 case 1: compat->sig[1] = (set->sig[0] >> 32); compat->sig[0] = set->sig[0]; 531 } 532 } 533 534 #ifdef CONFIG_NUMA 535 COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages, 536 compat_uptr_t __user *, pages32, 537 const int __user *, nodes, 538 int __user *, status, 539 int, flags) 540 { 541 const void __user * __user *pages; 542 int i; 543 544 pages = compat_alloc_user_space(nr_pages * sizeof(void *)); 545 for (i = 0; i < nr_pages; i++) { 546 compat_uptr_t p; 547 548 if (get_user(p, pages32 + i) || 549 put_user(compat_ptr(p), pages + i)) 550 return -EFAULT; 551 } 552 return sys_move_pages(pid, nr_pages, pages, nodes, status, flags); 553 } 554 555 COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid, 556 compat_ulong_t, maxnode, 557 const compat_ulong_t __user *, old_nodes, 558 const compat_ulong_t __user *, new_nodes) 559 { 560 unsigned long __user *old = NULL; 561 unsigned long __user *new = NULL; 562 nodemask_t tmp_mask; 563 unsigned long nr_bits; 564 unsigned long size; 565 566 nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES); 567 size = ALIGN(nr_bits, BITS_PER_LONG) / 8; 568 if (old_nodes) { 569 if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits)) 570 return -EFAULT; 571 old = compat_alloc_user_space(new_nodes ? size * 2 : size); 572 if (new_nodes) 573 new = old + size / sizeof(unsigned long); 574 if (copy_to_user(old, nodes_addr(tmp_mask), size)) 575 return -EFAULT; 576 } 577 if (new_nodes) { 578 if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits)) 579 return -EFAULT; 580 if (new == NULL) 581 new = compat_alloc_user_space(size); 582 if (copy_to_user(new, nodes_addr(tmp_mask), size)) 583 return -EFAULT; 584 } 585 return sys_migrate_pages(pid, nr_bits + 1, old, new); 586 } 587 #endif 588 589 COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval, 590 compat_pid_t, pid, 591 struct compat_timespec __user *, interval) 592 { 593 struct timespec t; 594 int ret; 595 mm_segment_t old_fs = get_fs(); 596 597 set_fs(KERNEL_DS); 598 ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t); 599 set_fs(old_fs); 600 if (compat_put_timespec(&t, interval)) 601 return -EFAULT; 602 return ret; 603 } 604 605 /* 606 * Allocate user-space memory for the duration of a single system call, 607 * in order to marshall parameters inside a compat thunk. 608 */ 609 void __user *compat_alloc_user_space(unsigned long len) 610 { 611 void __user *ptr; 612 613 /* If len would occupy more than half of the entire compat space... */ 614 if (unlikely(len > (((compat_uptr_t)~0) >> 1))) 615 return NULL; 616 617 ptr = arch_compat_alloc_user_space(len); 618 619 if (unlikely(!access_ok(VERIFY_WRITE, ptr, len))) 620 return NULL; 621 622 return ptr; 623 } 624 EXPORT_SYMBOL_GPL(compat_alloc_user_space); 625