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 memset(txc, 0, sizeof(struct timex)); 38 if (copy_from_user(&tx32, utp, sizeof(struct compat_timex))) 39 return -EFAULT; 40 41 txc->modes = tx32.modes; 42 txc->offset = tx32.offset; 43 txc->freq = tx32.freq; 44 txc->maxerror = tx32.maxerror; 45 txc->esterror = tx32.esterror; 46 txc->status = tx32.status; 47 txc->constant = tx32.constant; 48 txc->precision = tx32.precision; 49 txc->tolerance = tx32.tolerance; 50 txc->time.tv_sec = tx32.time.tv_sec; 51 txc->time.tv_usec = tx32.time.tv_usec; 52 txc->tick = tx32.tick; 53 txc->ppsfreq = tx32.ppsfreq; 54 txc->jitter = tx32.jitter; 55 txc->shift = tx32.shift; 56 txc->stabil = tx32.stabil; 57 txc->jitcnt = tx32.jitcnt; 58 txc->calcnt = tx32.calcnt; 59 txc->errcnt = tx32.errcnt; 60 txc->stbcnt = tx32.stbcnt; 61 62 return 0; 63 } 64 65 int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc) 66 { 67 struct compat_timex tx32; 68 69 memset(&tx32, 0, sizeof(struct compat_timex)); 70 tx32.modes = txc->modes; 71 tx32.offset = txc->offset; 72 tx32.freq = txc->freq; 73 tx32.maxerror = txc->maxerror; 74 tx32.esterror = txc->esterror; 75 tx32.status = txc->status; 76 tx32.constant = txc->constant; 77 tx32.precision = txc->precision; 78 tx32.tolerance = txc->tolerance; 79 tx32.time.tv_sec = txc->time.tv_sec; 80 tx32.time.tv_usec = txc->time.tv_usec; 81 tx32.tick = txc->tick; 82 tx32.ppsfreq = txc->ppsfreq; 83 tx32.jitter = txc->jitter; 84 tx32.shift = txc->shift; 85 tx32.stabil = txc->stabil; 86 tx32.jitcnt = txc->jitcnt; 87 tx32.calcnt = txc->calcnt; 88 tx32.errcnt = txc->errcnt; 89 tx32.stbcnt = txc->stbcnt; 90 tx32.tai = txc->tai; 91 if (copy_to_user(utp, &tx32, sizeof(struct compat_timex))) 92 return -EFAULT; 93 return 0; 94 } 95 96 static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv) 97 { 98 return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) || 99 __get_user(tv->tv_sec, &ctv->tv_sec) || 100 __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; 101 } 102 103 static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv) 104 { 105 return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) || 106 __put_user(tv->tv_sec, &ctv->tv_sec) || 107 __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; 108 } 109 110 static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts) 111 { 112 return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) || 113 __get_user(ts->tv_sec, &cts->tv_sec) || 114 __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; 115 } 116 117 static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts) 118 { 119 return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) || 120 __put_user(ts->tv_sec, &cts->tv_sec) || 121 __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; 122 } 123 124 static int __compat_get_timespec64(struct timespec64 *ts64, 125 const struct compat_timespec __user *cts) 126 { 127 struct compat_timespec ts; 128 int ret; 129 130 ret = copy_from_user(&ts, cts, sizeof(ts)); 131 if (ret) 132 return -EFAULT; 133 134 ts64->tv_sec = ts.tv_sec; 135 ts64->tv_nsec = ts.tv_nsec; 136 137 return 0; 138 } 139 140 static int __compat_put_timespec64(const struct timespec64 *ts64, 141 struct compat_timespec __user *cts) 142 { 143 struct compat_timespec ts = { 144 .tv_sec = ts64->tv_sec, 145 .tv_nsec = ts64->tv_nsec 146 }; 147 return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0; 148 } 149 150 int compat_get_timespec64(struct timespec64 *ts, const void __user *uts) 151 { 152 if (COMPAT_USE_64BIT_TIME) 153 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 154 else 155 return __compat_get_timespec64(ts, uts); 156 } 157 EXPORT_SYMBOL_GPL(compat_get_timespec64); 158 159 int compat_put_timespec64(const struct timespec64 *ts, void __user *uts) 160 { 161 if (COMPAT_USE_64BIT_TIME) 162 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 163 else 164 return __compat_put_timespec64(ts, uts); 165 } 166 EXPORT_SYMBOL_GPL(compat_put_timespec64); 167 168 int compat_get_timeval(struct timeval *tv, const void __user *utv) 169 { 170 if (COMPAT_USE_64BIT_TIME) 171 return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0; 172 else 173 return __compat_get_timeval(tv, utv); 174 } 175 EXPORT_SYMBOL_GPL(compat_get_timeval); 176 177 int compat_put_timeval(const struct timeval *tv, void __user *utv) 178 { 179 if (COMPAT_USE_64BIT_TIME) 180 return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0; 181 else 182 return __compat_put_timeval(tv, utv); 183 } 184 EXPORT_SYMBOL_GPL(compat_put_timeval); 185 186 int compat_get_timespec(struct timespec *ts, const void __user *uts) 187 { 188 if (COMPAT_USE_64BIT_TIME) 189 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 190 else 191 return __compat_get_timespec(ts, uts); 192 } 193 EXPORT_SYMBOL_GPL(compat_get_timespec); 194 195 int compat_put_timespec(const struct timespec *ts, void __user *uts) 196 { 197 if (COMPAT_USE_64BIT_TIME) 198 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 199 else 200 return __compat_put_timespec(ts, uts); 201 } 202 EXPORT_SYMBOL_GPL(compat_put_timespec); 203 204 int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i) 205 { 206 struct compat_itimerval v32; 207 208 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval))) 209 return -EFAULT; 210 o->it_interval.tv_sec = v32.it_interval.tv_sec; 211 o->it_interval.tv_usec = v32.it_interval.tv_usec; 212 o->it_value.tv_sec = v32.it_value.tv_sec; 213 o->it_value.tv_usec = v32.it_value.tv_usec; 214 return 0; 215 } 216 217 int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i) 218 { 219 struct compat_itimerval v32; 220 221 v32.it_interval.tv_sec = i->it_interval.tv_sec; 222 v32.it_interval.tv_usec = i->it_interval.tv_usec; 223 v32.it_value.tv_sec = i->it_value.tv_sec; 224 v32.it_value.tv_usec = i->it_value.tv_usec; 225 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0; 226 } 227 228 #ifdef __ARCH_WANT_SYS_SIGPROCMASK 229 230 /* 231 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the 232 * blocked set of signals to the supplied signal set 233 */ 234 static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set) 235 { 236 memcpy(blocked->sig, &set, sizeof(set)); 237 } 238 239 COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how, 240 compat_old_sigset_t __user *, nset, 241 compat_old_sigset_t __user *, oset) 242 { 243 old_sigset_t old_set, new_set; 244 sigset_t new_blocked; 245 246 old_set = current->blocked.sig[0]; 247 248 if (nset) { 249 if (get_user(new_set, nset)) 250 return -EFAULT; 251 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); 252 253 new_blocked = current->blocked; 254 255 switch (how) { 256 case SIG_BLOCK: 257 sigaddsetmask(&new_blocked, new_set); 258 break; 259 case SIG_UNBLOCK: 260 sigdelsetmask(&new_blocked, new_set); 261 break; 262 case SIG_SETMASK: 263 compat_sig_setmask(&new_blocked, new_set); 264 break; 265 default: 266 return -EINVAL; 267 } 268 269 set_current_blocked(&new_blocked); 270 } 271 272 if (oset) { 273 if (put_user(old_set, oset)) 274 return -EFAULT; 275 } 276 277 return 0; 278 } 279 280 #endif 281 282 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru) 283 { 284 struct compat_rusage r32; 285 memset(&r32, 0, sizeof(r32)); 286 r32.ru_utime.tv_sec = r->ru_utime.tv_sec; 287 r32.ru_utime.tv_usec = r->ru_utime.tv_usec; 288 r32.ru_stime.tv_sec = r->ru_stime.tv_sec; 289 r32.ru_stime.tv_usec = r->ru_stime.tv_usec; 290 r32.ru_maxrss = r->ru_maxrss; 291 r32.ru_ixrss = r->ru_ixrss; 292 r32.ru_idrss = r->ru_idrss; 293 r32.ru_isrss = r->ru_isrss; 294 r32.ru_minflt = r->ru_minflt; 295 r32.ru_majflt = r->ru_majflt; 296 r32.ru_nswap = r->ru_nswap; 297 r32.ru_inblock = r->ru_inblock; 298 r32.ru_oublock = r->ru_oublock; 299 r32.ru_msgsnd = r->ru_msgsnd; 300 r32.ru_msgrcv = r->ru_msgrcv; 301 r32.ru_nsignals = r->ru_nsignals; 302 r32.ru_nvcsw = r->ru_nvcsw; 303 r32.ru_nivcsw = r->ru_nivcsw; 304 if (copy_to_user(ru, &r32, sizeof(r32))) 305 return -EFAULT; 306 return 0; 307 } 308 309 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr, 310 unsigned len, struct cpumask *new_mask) 311 { 312 unsigned long *k; 313 314 if (len < cpumask_size()) 315 memset(new_mask, 0, cpumask_size()); 316 else if (len > cpumask_size()) 317 len = cpumask_size(); 318 319 k = cpumask_bits(new_mask); 320 return compat_get_bitmap(k, user_mask_ptr, len * 8); 321 } 322 323 COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid, 324 unsigned int, len, 325 compat_ulong_t __user *, user_mask_ptr) 326 { 327 cpumask_var_t new_mask; 328 int retval; 329 330 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) 331 return -ENOMEM; 332 333 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask); 334 if (retval) 335 goto out; 336 337 retval = sched_setaffinity(pid, new_mask); 338 out: 339 free_cpumask_var(new_mask); 340 return retval; 341 } 342 343 COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len, 344 compat_ulong_t __user *, user_mask_ptr) 345 { 346 int ret; 347 cpumask_var_t mask; 348 349 if ((len * BITS_PER_BYTE) < nr_cpu_ids) 350 return -EINVAL; 351 if (len & (sizeof(compat_ulong_t)-1)) 352 return -EINVAL; 353 354 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 355 return -ENOMEM; 356 357 ret = sched_getaffinity(pid, mask); 358 if (ret == 0) { 359 unsigned int retlen = min(len, cpumask_size()); 360 361 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8)) 362 ret = -EFAULT; 363 else 364 ret = retlen; 365 } 366 free_cpumask_var(mask); 367 368 return ret; 369 } 370 371 int get_compat_itimerspec64(struct itimerspec64 *its, 372 const struct compat_itimerspec __user *uits) 373 { 374 375 if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) || 376 __compat_get_timespec64(&its->it_value, &uits->it_value)) 377 return -EFAULT; 378 return 0; 379 } 380 EXPORT_SYMBOL_GPL(get_compat_itimerspec64); 381 382 int put_compat_itimerspec64(const struct itimerspec64 *its, 383 struct compat_itimerspec __user *uits) 384 { 385 if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) || 386 __compat_put_timespec64(&its->it_value, &uits->it_value)) 387 return -EFAULT; 388 return 0; 389 } 390 EXPORT_SYMBOL_GPL(put_compat_itimerspec64); 391 392 /* 393 * We currently only need the following fields from the sigevent 394 * structure: sigev_value, sigev_signo, sig_notify and (sometimes 395 * sigev_notify_thread_id). The others are handled in user mode. 396 * We also assume that copying sigev_value.sival_int is sufficient 397 * to keep all the bits of sigev_value.sival_ptr intact. 398 */ 399 int get_compat_sigevent(struct sigevent *event, 400 const struct compat_sigevent __user *u_event) 401 { 402 memset(event, 0, sizeof(*event)); 403 return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) || 404 __get_user(event->sigev_value.sival_int, 405 &u_event->sigev_value.sival_int) || 406 __get_user(event->sigev_signo, &u_event->sigev_signo) || 407 __get_user(event->sigev_notify, &u_event->sigev_notify) || 408 __get_user(event->sigev_notify_thread_id, 409 &u_event->sigev_notify_thread_id)) 410 ? -EFAULT : 0; 411 } 412 413 long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, 414 unsigned long bitmap_size) 415 { 416 unsigned long nr_compat_longs; 417 418 /* align bitmap up to nearest compat_long_t boundary */ 419 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 420 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 421 422 if (!access_ok(VERIFY_READ, umask, bitmap_size / 8)) 423 return -EFAULT; 424 425 user_access_begin(); 426 while (nr_compat_longs > 1) { 427 compat_ulong_t l1, l2; 428 unsafe_get_user(l1, umask++, Efault); 429 unsafe_get_user(l2, umask++, Efault); 430 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1; 431 nr_compat_longs -= 2; 432 } 433 if (nr_compat_longs) 434 unsafe_get_user(*mask, umask++, Efault); 435 user_access_end(); 436 return 0; 437 438 Efault: 439 user_access_end(); 440 return -EFAULT; 441 } 442 443 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, 444 unsigned long bitmap_size) 445 { 446 unsigned long nr_compat_longs; 447 448 /* align bitmap up to nearest compat_long_t boundary */ 449 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 450 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 451 452 if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8)) 453 return -EFAULT; 454 455 user_access_begin(); 456 while (nr_compat_longs > 1) { 457 unsigned long m = *mask++; 458 unsafe_put_user((compat_ulong_t)m, umask++, Efault); 459 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault); 460 nr_compat_longs -= 2; 461 } 462 if (nr_compat_longs) 463 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault); 464 user_access_end(); 465 return 0; 466 Efault: 467 user_access_end(); 468 return -EFAULT; 469 } 470 471 int 472 get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat) 473 { 474 #ifdef __BIG_ENDIAN 475 compat_sigset_t v; 476 if (copy_from_user(&v, compat, sizeof(compat_sigset_t))) 477 return -EFAULT; 478 switch (_NSIG_WORDS) { 479 case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 ); 480 case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 ); 481 case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 ); 482 case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 ); 483 } 484 #else 485 if (copy_from_user(set, compat, sizeof(compat_sigset_t))) 486 return -EFAULT; 487 #endif 488 return 0; 489 } 490 EXPORT_SYMBOL_GPL(get_compat_sigset); 491 492 /* 493 * Allocate user-space memory for the duration of a single system call, 494 * in order to marshall parameters inside a compat thunk. 495 */ 496 void __user *compat_alloc_user_space(unsigned long len) 497 { 498 void __user *ptr; 499 500 /* If len would occupy more than half of the entire compat space... */ 501 if (unlikely(len > (((compat_uptr_t)~0) >> 1))) 502 return NULL; 503 504 ptr = arch_compat_alloc_user_space(len); 505 506 if (unlikely(!access_ok(VERIFY_WRITE, ptr, len))) 507 return NULL; 508 509 return ptr; 510 } 511 EXPORT_SYMBOL_GPL(compat_alloc_user_space); 512