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 get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i) 204 { 205 struct compat_itimerval v32; 206 207 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval))) 208 return -EFAULT; 209 o->it_interval.tv_sec = v32.it_interval.tv_sec; 210 o->it_interval.tv_usec = v32.it_interval.tv_usec; 211 o->it_value.tv_sec = v32.it_value.tv_sec; 212 o->it_value.tv_usec = v32.it_value.tv_usec; 213 return 0; 214 } 215 216 int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i) 217 { 218 struct compat_itimerval v32; 219 220 v32.it_interval.tv_sec = i->it_interval.tv_sec; 221 v32.it_interval.tv_usec = i->it_interval.tv_usec; 222 v32.it_value.tv_sec = i->it_value.tv_sec; 223 v32.it_value.tv_usec = i->it_value.tv_usec; 224 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0; 225 } 226 227 #ifdef __ARCH_WANT_SYS_SIGPROCMASK 228 229 /* 230 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the 231 * blocked set of signals to the supplied signal set 232 */ 233 static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set) 234 { 235 memcpy(blocked->sig, &set, sizeof(set)); 236 } 237 238 COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how, 239 compat_old_sigset_t __user *, nset, 240 compat_old_sigset_t __user *, oset) 241 { 242 old_sigset_t old_set, new_set; 243 sigset_t new_blocked; 244 245 old_set = current->blocked.sig[0]; 246 247 if (nset) { 248 if (get_user(new_set, nset)) 249 return -EFAULT; 250 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); 251 252 new_blocked = current->blocked; 253 254 switch (how) { 255 case SIG_BLOCK: 256 sigaddsetmask(&new_blocked, new_set); 257 break; 258 case SIG_UNBLOCK: 259 sigdelsetmask(&new_blocked, new_set); 260 break; 261 case SIG_SETMASK: 262 compat_sig_setmask(&new_blocked, new_set); 263 break; 264 default: 265 return -EINVAL; 266 } 267 268 set_current_blocked(&new_blocked); 269 } 270 271 if (oset) { 272 if (put_user(old_set, oset)) 273 return -EFAULT; 274 } 275 276 return 0; 277 } 278 279 #endif 280 281 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru) 282 { 283 struct compat_rusage r32; 284 memset(&r32, 0, sizeof(r32)); 285 r32.ru_utime.tv_sec = r->ru_utime.tv_sec; 286 r32.ru_utime.tv_usec = r->ru_utime.tv_usec; 287 r32.ru_stime.tv_sec = r->ru_stime.tv_sec; 288 r32.ru_stime.tv_usec = r->ru_stime.tv_usec; 289 r32.ru_maxrss = r->ru_maxrss; 290 r32.ru_ixrss = r->ru_ixrss; 291 r32.ru_idrss = r->ru_idrss; 292 r32.ru_isrss = r->ru_isrss; 293 r32.ru_minflt = r->ru_minflt; 294 r32.ru_majflt = r->ru_majflt; 295 r32.ru_nswap = r->ru_nswap; 296 r32.ru_inblock = r->ru_inblock; 297 r32.ru_oublock = r->ru_oublock; 298 r32.ru_msgsnd = r->ru_msgsnd; 299 r32.ru_msgrcv = r->ru_msgrcv; 300 r32.ru_nsignals = r->ru_nsignals; 301 r32.ru_nvcsw = r->ru_nvcsw; 302 r32.ru_nivcsw = r->ru_nivcsw; 303 if (copy_to_user(ru, &r32, sizeof(r32))) 304 return -EFAULT; 305 return 0; 306 } 307 308 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr, 309 unsigned len, struct cpumask *new_mask) 310 { 311 unsigned long *k; 312 313 if (len < cpumask_size()) 314 memset(new_mask, 0, cpumask_size()); 315 else if (len > cpumask_size()) 316 len = cpumask_size(); 317 318 k = cpumask_bits(new_mask); 319 return compat_get_bitmap(k, user_mask_ptr, len * 8); 320 } 321 322 COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid, 323 unsigned int, len, 324 compat_ulong_t __user *, user_mask_ptr) 325 { 326 cpumask_var_t new_mask; 327 int retval; 328 329 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) 330 return -ENOMEM; 331 332 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask); 333 if (retval) 334 goto out; 335 336 retval = sched_setaffinity(pid, new_mask); 337 out: 338 free_cpumask_var(new_mask); 339 return retval; 340 } 341 342 COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len, 343 compat_ulong_t __user *, user_mask_ptr) 344 { 345 int ret; 346 cpumask_var_t mask; 347 348 if ((len * BITS_PER_BYTE) < nr_cpu_ids) 349 return -EINVAL; 350 if (len & (sizeof(compat_ulong_t)-1)) 351 return -EINVAL; 352 353 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 354 return -ENOMEM; 355 356 ret = sched_getaffinity(pid, mask); 357 if (ret == 0) { 358 unsigned int retlen = min(len, cpumask_size()); 359 360 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8)) 361 ret = -EFAULT; 362 else 363 ret = retlen; 364 } 365 free_cpumask_var(mask); 366 367 return ret; 368 } 369 370 int get_compat_itimerspec64(struct itimerspec64 *its, 371 const struct compat_itimerspec __user *uits) 372 { 373 374 if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) || 375 __compat_get_timespec64(&its->it_value, &uits->it_value)) 376 return -EFAULT; 377 return 0; 378 } 379 EXPORT_SYMBOL_GPL(get_compat_itimerspec64); 380 381 int put_compat_itimerspec64(const struct itimerspec64 *its, 382 struct compat_itimerspec __user *uits) 383 { 384 if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) || 385 __compat_put_timespec64(&its->it_value, &uits->it_value)) 386 return -EFAULT; 387 return 0; 388 } 389 EXPORT_SYMBOL_GPL(put_compat_itimerspec64); 390 391 /* 392 * We currently only need the following fields from the sigevent 393 * structure: sigev_value, sigev_signo, sig_notify and (sometimes 394 * sigev_notify_thread_id). The others are handled in user mode. 395 * We also assume that copying sigev_value.sival_int is sufficient 396 * to keep all the bits of sigev_value.sival_ptr intact. 397 */ 398 int get_compat_sigevent(struct sigevent *event, 399 const struct compat_sigevent __user *u_event) 400 { 401 memset(event, 0, sizeof(*event)); 402 return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) || 403 __get_user(event->sigev_value.sival_int, 404 &u_event->sigev_value.sival_int) || 405 __get_user(event->sigev_signo, &u_event->sigev_signo) || 406 __get_user(event->sigev_notify, &u_event->sigev_notify) || 407 __get_user(event->sigev_notify_thread_id, 408 &u_event->sigev_notify_thread_id)) 409 ? -EFAULT : 0; 410 } 411 412 long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, 413 unsigned long bitmap_size) 414 { 415 unsigned long nr_compat_longs; 416 417 /* align bitmap up to nearest compat_long_t boundary */ 418 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 419 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 420 421 if (!access_ok(VERIFY_READ, umask, bitmap_size / 8)) 422 return -EFAULT; 423 424 user_access_begin(); 425 while (nr_compat_longs > 1) { 426 compat_ulong_t l1, l2; 427 unsafe_get_user(l1, umask++, Efault); 428 unsafe_get_user(l2, umask++, Efault); 429 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1; 430 nr_compat_longs -= 2; 431 } 432 if (nr_compat_longs) 433 unsafe_get_user(*mask, umask++, Efault); 434 user_access_end(); 435 return 0; 436 437 Efault: 438 user_access_end(); 439 return -EFAULT; 440 } 441 442 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, 443 unsigned long bitmap_size) 444 { 445 unsigned long nr_compat_longs; 446 447 /* align bitmap up to nearest compat_long_t boundary */ 448 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 449 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 450 451 if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8)) 452 return -EFAULT; 453 454 user_access_begin(); 455 while (nr_compat_longs > 1) { 456 unsigned long m = *mask++; 457 unsafe_put_user((compat_ulong_t)m, umask++, Efault); 458 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault); 459 nr_compat_longs -= 2; 460 } 461 if (nr_compat_longs) 462 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault); 463 user_access_end(); 464 return 0; 465 Efault: 466 user_access_end(); 467 return -EFAULT; 468 } 469 470 int 471 get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat) 472 { 473 #ifdef __BIG_ENDIAN 474 compat_sigset_t v; 475 if (copy_from_user(&v, compat, sizeof(compat_sigset_t))) 476 return -EFAULT; 477 switch (_NSIG_WORDS) { 478 case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 ); 479 case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 ); 480 case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 ); 481 case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 ); 482 } 483 #else 484 if (copy_from_user(set, compat, sizeof(compat_sigset_t))) 485 return -EFAULT; 486 #endif 487 return 0; 488 } 489 EXPORT_SYMBOL_GPL(get_compat_sigset); 490 491 /* 492 * Allocate user-space memory for the duration of a single system call, 493 * in order to marshall parameters inside a compat thunk. 494 */ 495 void __user *compat_alloc_user_space(unsigned long len) 496 { 497 void __user *ptr; 498 499 /* If len would occupy more than half of the entire compat space... */ 500 if (unlikely(len > (((compat_uptr_t)~0) >> 1))) 501 return NULL; 502 503 ptr = arch_compat_alloc_user_space(len); 504 505 if (unlikely(!access_ok(VERIFY_WRITE, ptr, len))) 506 return NULL; 507 508 return ptr; 509 } 510 EXPORT_SYMBOL_GPL(compat_alloc_user_space); 511