1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * This file contains the procedures for the handling of select and poll 4 * 5 * Created for Linux based loosely upon Mathius Lattner's minix 6 * patches by Peter MacDonald. Heavily edited by Linus. 7 * 8 * 4 February 1994 9 * COFF/ELF binary emulation. If the process has the STICKY_TIMEOUTS 10 * flag set in its personality we do *not* modify the given timeout 11 * parameter to reflect time remaining. 12 * 13 * 24 January 2000 14 * Changed sys_poll()/do_poll() to use PAGE_SIZE chunk-based allocation 15 * of fds to overcome nfds < 16390 descriptors limit (Tigran Aivazian). 16 */ 17 18 #include <linux/compat.h> 19 #include <linux/kernel.h> 20 #include <linux/sched/signal.h> 21 #include <linux/sched/rt.h> 22 #include <linux/syscalls.h> 23 #include <linux/export.h> 24 #include <linux/slab.h> 25 #include <linux/poll.h> 26 #include <linux/personality.h> /* for STICKY_TIMEOUTS */ 27 #include <linux/file.h> 28 #include <linux/fdtable.h> 29 #include <linux/fs.h> 30 #include <linux/rcupdate.h> 31 #include <linux/hrtimer.h> 32 #include <linux/freezer.h> 33 #include <net/busy_poll.h> 34 #include <linux/vmalloc.h> 35 36 #include <linux/uaccess.h> 37 38 39 /* 40 * Estimate expected accuracy in ns from a timeval. 41 * 42 * After quite a bit of churning around, we've settled on 43 * a simple thing of taking 0.1% of the timeout as the 44 * slack, with a cap of 100 msec. 45 * "nice" tasks get a 0.5% slack instead. 46 * 47 * Consider this comment an open invitation to come up with even 48 * better solutions.. 49 */ 50 51 #define MAX_SLACK (100 * NSEC_PER_MSEC) 52 53 static long __estimate_accuracy(struct timespec64 *tv) 54 { 55 long slack; 56 int divfactor = 1000; 57 58 if (tv->tv_sec < 0) 59 return 0; 60 61 if (task_nice(current) > 0) 62 divfactor = divfactor / 5; 63 64 if (tv->tv_sec > MAX_SLACK / (NSEC_PER_SEC/divfactor)) 65 return MAX_SLACK; 66 67 slack = tv->tv_nsec / divfactor; 68 slack += tv->tv_sec * (NSEC_PER_SEC/divfactor); 69 70 if (slack > MAX_SLACK) 71 return MAX_SLACK; 72 73 return slack; 74 } 75 76 u64 select_estimate_accuracy(struct timespec64 *tv) 77 { 78 u64 ret; 79 struct timespec64 now; 80 u64 slack = current->timer_slack_ns; 81 82 if (slack == 0) 83 return 0; 84 85 ktime_get_ts64(&now); 86 now = timespec64_sub(*tv, now); 87 ret = __estimate_accuracy(&now); 88 if (ret < slack) 89 return slack; 90 return ret; 91 } 92 93 94 95 struct poll_table_page { 96 struct poll_table_page * next; 97 struct poll_table_entry * entry; 98 struct poll_table_entry entries[]; 99 }; 100 101 #define POLL_TABLE_FULL(table) \ 102 ((unsigned long)((table)->entry+1) > PAGE_SIZE + (unsigned long)(table)) 103 104 /* 105 * Ok, Peter made a complicated, but straightforward multiple_wait() function. 106 * I have rewritten this, taking some shortcuts: This code may not be easy to 107 * follow, but it should be free of race-conditions, and it's practical. If you 108 * understand what I'm doing here, then you understand how the linux 109 * sleep/wakeup mechanism works. 110 * 111 * Two very simple procedures, poll_wait() and poll_freewait() make all the 112 * work. poll_wait() is an inline-function defined in <linux/poll.h>, 113 * as all select/poll functions have to call it to add an entry to the 114 * poll table. 115 */ 116 static void __pollwait(struct file *filp, wait_queue_head_t *wait_address, 117 poll_table *p); 118 119 void poll_initwait(struct poll_wqueues *pwq) 120 { 121 init_poll_funcptr(&pwq->pt, __pollwait); 122 pwq->polling_task = current; 123 pwq->triggered = 0; 124 pwq->error = 0; 125 pwq->table = NULL; 126 pwq->inline_index = 0; 127 } 128 EXPORT_SYMBOL(poll_initwait); 129 130 static void free_poll_entry(struct poll_table_entry *entry) 131 { 132 remove_wait_queue(entry->wait_address, &entry->wait); 133 fput(entry->filp); 134 } 135 136 void poll_freewait(struct poll_wqueues *pwq) 137 { 138 struct poll_table_page * p = pwq->table; 139 int i; 140 for (i = 0; i < pwq->inline_index; i++) 141 free_poll_entry(pwq->inline_entries + i); 142 while (p) { 143 struct poll_table_entry * entry; 144 struct poll_table_page *old; 145 146 entry = p->entry; 147 do { 148 entry--; 149 free_poll_entry(entry); 150 } while (entry > p->entries); 151 old = p; 152 p = p->next; 153 free_page((unsigned long) old); 154 } 155 } 156 EXPORT_SYMBOL(poll_freewait); 157 158 static struct poll_table_entry *poll_get_entry(struct poll_wqueues *p) 159 { 160 struct poll_table_page *table = p->table; 161 162 if (p->inline_index < N_INLINE_POLL_ENTRIES) 163 return p->inline_entries + p->inline_index++; 164 165 if (!table || POLL_TABLE_FULL(table)) { 166 struct poll_table_page *new_table; 167 168 new_table = (struct poll_table_page *) __get_free_page(GFP_KERNEL); 169 if (!new_table) { 170 p->error = -ENOMEM; 171 return NULL; 172 } 173 new_table->entry = new_table->entries; 174 new_table->next = table; 175 p->table = new_table; 176 table = new_table; 177 } 178 179 return table->entry++; 180 } 181 182 static int __pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) 183 { 184 struct poll_wqueues *pwq = wait->private; 185 DECLARE_WAITQUEUE(dummy_wait, pwq->polling_task); 186 187 /* 188 * Although this function is called under waitqueue lock, LOCK 189 * doesn't imply write barrier and the users expect write 190 * barrier semantics on wakeup functions. The following 191 * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up() 192 * and is paired with smp_store_mb() in poll_schedule_timeout. 193 */ 194 smp_wmb(); 195 pwq->triggered = 1; 196 197 /* 198 * Perform the default wake up operation using a dummy 199 * waitqueue. 200 * 201 * TODO: This is hacky but there currently is no interface to 202 * pass in @sync. @sync is scheduled to be removed and once 203 * that happens, wake_up_process() can be used directly. 204 */ 205 return default_wake_function(&dummy_wait, mode, sync, key); 206 } 207 208 static int pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) 209 { 210 struct poll_table_entry *entry; 211 212 entry = container_of(wait, struct poll_table_entry, wait); 213 if (key && !(key_to_poll(key) & entry->key)) 214 return 0; 215 return __pollwake(wait, mode, sync, key); 216 } 217 218 /* Add a new entry */ 219 static void __pollwait(struct file *filp, wait_queue_head_t *wait_address, 220 poll_table *p) 221 { 222 struct poll_wqueues *pwq = container_of(p, struct poll_wqueues, pt); 223 struct poll_table_entry *entry = poll_get_entry(pwq); 224 if (!entry) 225 return; 226 entry->filp = get_file(filp); 227 entry->wait_address = wait_address; 228 entry->key = p->_key; 229 init_waitqueue_func_entry(&entry->wait, pollwake); 230 entry->wait.private = pwq; 231 add_wait_queue(wait_address, &entry->wait); 232 } 233 234 static int poll_schedule_timeout(struct poll_wqueues *pwq, int state, 235 ktime_t *expires, unsigned long slack) 236 { 237 int rc = -EINTR; 238 239 set_current_state(state); 240 if (!pwq->triggered) 241 rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS); 242 __set_current_state(TASK_RUNNING); 243 244 /* 245 * Prepare for the next iteration. 246 * 247 * The following smp_store_mb() serves two purposes. First, it's 248 * the counterpart rmb of the wmb in pollwake() such that data 249 * written before wake up is always visible after wake up. 250 * Second, the full barrier guarantees that triggered clearing 251 * doesn't pass event check of the next iteration. Note that 252 * this problem doesn't exist for the first iteration as 253 * add_wait_queue() has full barrier semantics. 254 */ 255 smp_store_mb(pwq->triggered, 0); 256 257 return rc; 258 } 259 260 /** 261 * poll_select_set_timeout - helper function to setup the timeout value 262 * @to: pointer to timespec64 variable for the final timeout 263 * @sec: seconds (from user space) 264 * @nsec: nanoseconds (from user space) 265 * 266 * Note, we do not use a timespec for the user space value here, That 267 * way we can use the function for timeval and compat interfaces as well. 268 * 269 * Returns -EINVAL if sec/nsec are not normalized. Otherwise 0. 270 */ 271 int poll_select_set_timeout(struct timespec64 *to, time64_t sec, long nsec) 272 { 273 struct timespec64 ts = {.tv_sec = sec, .tv_nsec = nsec}; 274 275 if (!timespec64_valid(&ts)) 276 return -EINVAL; 277 278 /* Optimize for the zero timeout value here */ 279 if (!sec && !nsec) { 280 to->tv_sec = to->tv_nsec = 0; 281 } else { 282 ktime_get_ts64(to); 283 *to = timespec64_add_safe(*to, ts); 284 } 285 return 0; 286 } 287 288 enum poll_time_type { 289 PT_TIMEVAL = 0, 290 PT_OLD_TIMEVAL = 1, 291 PT_TIMESPEC = 2, 292 PT_OLD_TIMESPEC = 3, 293 }; 294 295 static int poll_select_finish(struct timespec64 *end_time, 296 void __user *p, 297 enum poll_time_type pt_type, int ret) 298 { 299 struct timespec64 rts; 300 301 restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); 302 303 if (!p) 304 return ret; 305 306 if (current->personality & STICKY_TIMEOUTS) 307 goto sticky; 308 309 /* No update for zero timeout */ 310 if (!end_time->tv_sec && !end_time->tv_nsec) 311 return ret; 312 313 ktime_get_ts64(&rts); 314 rts = timespec64_sub(*end_time, rts); 315 if (rts.tv_sec < 0) 316 rts.tv_sec = rts.tv_nsec = 0; 317 318 319 switch (pt_type) { 320 case PT_TIMEVAL: 321 { 322 struct __kernel_old_timeval rtv; 323 324 if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec)) 325 memset(&rtv, 0, sizeof(rtv)); 326 rtv.tv_sec = rts.tv_sec; 327 rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; 328 if (!copy_to_user(p, &rtv, sizeof(rtv))) 329 return ret; 330 } 331 break; 332 case PT_OLD_TIMEVAL: 333 { 334 struct old_timeval32 rtv; 335 336 rtv.tv_sec = rts.tv_sec; 337 rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; 338 if (!copy_to_user(p, &rtv, sizeof(rtv))) 339 return ret; 340 } 341 break; 342 case PT_TIMESPEC: 343 if (!put_timespec64(&rts, p)) 344 return ret; 345 break; 346 case PT_OLD_TIMESPEC: 347 if (!put_old_timespec32(&rts, p)) 348 return ret; 349 break; 350 default: 351 BUG(); 352 } 353 /* 354 * If an application puts its timeval in read-only memory, we 355 * don't want the Linux-specific update to the timeval to 356 * cause a fault after the select has completed 357 * successfully. However, because we're not updating the 358 * timeval, we can't restart the system call. 359 */ 360 361 sticky: 362 if (ret == -ERESTARTNOHAND) 363 ret = -EINTR; 364 return ret; 365 } 366 367 /* 368 * Scalable version of the fd_set. 369 */ 370 371 typedef struct { 372 unsigned long *in, *out, *ex; 373 unsigned long *res_in, *res_out, *res_ex; 374 } fd_set_bits; 375 376 /* 377 * How many longwords for "nr" bits? 378 */ 379 #define FDS_BITPERLONG (8*sizeof(long)) 380 #define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG) 381 #define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long)) 382 383 /* 384 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned. 385 */ 386 static inline 387 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) 388 { 389 nr = FDS_BYTES(nr); 390 if (ufdset) 391 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0; 392 393 memset(fdset, 0, nr); 394 return 0; 395 } 396 397 static inline unsigned long __must_check 398 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) 399 { 400 if (ufdset) 401 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr)); 402 return 0; 403 } 404 405 static inline 406 void zero_fd_set(unsigned long nr, unsigned long *fdset) 407 { 408 memset(fdset, 0, FDS_BYTES(nr)); 409 } 410 411 #define FDS_IN(fds, n) (fds->in + n) 412 #define FDS_OUT(fds, n) (fds->out + n) 413 #define FDS_EX(fds, n) (fds->ex + n) 414 415 #define BITS(fds, n) (*FDS_IN(fds, n)|*FDS_OUT(fds, n)|*FDS_EX(fds, n)) 416 417 static int max_select_fd(unsigned long n, fd_set_bits *fds) 418 { 419 unsigned long *open_fds; 420 unsigned long set; 421 int max; 422 struct fdtable *fdt; 423 424 /* handle last in-complete long-word first */ 425 set = ~(~0UL << (n & (BITS_PER_LONG-1))); 426 n /= BITS_PER_LONG; 427 fdt = files_fdtable(current->files); 428 open_fds = fdt->open_fds + n; 429 max = 0; 430 if (set) { 431 set &= BITS(fds, n); 432 if (set) { 433 if (!(set & ~*open_fds)) 434 goto get_max; 435 return -EBADF; 436 } 437 } 438 while (n) { 439 open_fds--; 440 n--; 441 set = BITS(fds, n); 442 if (!set) 443 continue; 444 if (set & ~*open_fds) 445 return -EBADF; 446 if (max) 447 continue; 448 get_max: 449 do { 450 max++; 451 set >>= 1; 452 } while (set); 453 max += n * BITS_PER_LONG; 454 } 455 456 return max; 457 } 458 459 #define POLLIN_SET (EPOLLRDNORM | EPOLLRDBAND | EPOLLIN | EPOLLHUP | EPOLLERR |\ 460 EPOLLNVAL) 461 #define POLLOUT_SET (EPOLLWRBAND | EPOLLWRNORM | EPOLLOUT | EPOLLERR |\ 462 EPOLLNVAL) 463 #define POLLEX_SET (EPOLLPRI | EPOLLNVAL) 464 465 static inline __poll_t select_poll_one(int fd, poll_table *wait, unsigned long in, 466 unsigned long out, unsigned long bit, 467 __poll_t ll_flag) 468 { 469 CLASS(fd, f)(fd); 470 471 if (fd_empty(f)) 472 return EPOLLNVAL; 473 474 wait->_key = POLLEX_SET | ll_flag; 475 if (in & bit) 476 wait->_key |= POLLIN_SET; 477 if (out & bit) 478 wait->_key |= POLLOUT_SET; 479 480 return vfs_poll(fd_file(f), wait); 481 } 482 483 static noinline_for_stack int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time) 484 { 485 ktime_t expire, *to = NULL; 486 struct poll_wqueues table; 487 poll_table *wait; 488 int retval, i, timed_out = 0; 489 u64 slack = 0; 490 __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; 491 unsigned long busy_start = 0; 492 493 rcu_read_lock(); 494 retval = max_select_fd(n, fds); 495 rcu_read_unlock(); 496 497 if (retval < 0) 498 return retval; 499 n = retval; 500 501 poll_initwait(&table); 502 wait = &table.pt; 503 if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { 504 wait->_qproc = NULL; 505 timed_out = 1; 506 } 507 508 if (end_time && !timed_out) 509 slack = select_estimate_accuracy(end_time); 510 511 retval = 0; 512 for (;;) { 513 unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp; 514 bool can_busy_loop = false; 515 516 inp = fds->in; outp = fds->out; exp = fds->ex; 517 rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex; 518 519 for (i = 0; i < n; ++rinp, ++routp, ++rexp) { 520 unsigned long in, out, ex, all_bits, bit = 1, j; 521 unsigned long res_in = 0, res_out = 0, res_ex = 0; 522 __poll_t mask; 523 524 in = *inp++; out = *outp++; ex = *exp++; 525 all_bits = in | out | ex; 526 if (all_bits == 0) { 527 i += BITS_PER_LONG; 528 continue; 529 } 530 531 for (j = 0; j < BITS_PER_LONG; ++j, ++i, bit <<= 1) { 532 if (i >= n) 533 break; 534 if (!(bit & all_bits)) 535 continue; 536 mask = select_poll_one(i, wait, in, out, bit, 537 busy_flag); 538 if ((mask & POLLIN_SET) && (in & bit)) { 539 res_in |= bit; 540 retval++; 541 wait->_qproc = NULL; 542 } 543 if ((mask & POLLOUT_SET) && (out & bit)) { 544 res_out |= bit; 545 retval++; 546 wait->_qproc = NULL; 547 } 548 if ((mask & POLLEX_SET) && (ex & bit)) { 549 res_ex |= bit; 550 retval++; 551 wait->_qproc = NULL; 552 } 553 /* got something, stop busy polling */ 554 if (retval) { 555 can_busy_loop = false; 556 busy_flag = 0; 557 558 /* 559 * only remember a returned 560 * POLL_BUSY_LOOP if we asked for it 561 */ 562 } else if (busy_flag & mask) 563 can_busy_loop = true; 564 565 } 566 if (res_in) 567 *rinp = res_in; 568 if (res_out) 569 *routp = res_out; 570 if (res_ex) 571 *rexp = res_ex; 572 cond_resched(); 573 } 574 wait->_qproc = NULL; 575 if (retval || timed_out || signal_pending(current)) 576 break; 577 if (table.error) { 578 retval = table.error; 579 break; 580 } 581 582 /* only if found POLL_BUSY_LOOP sockets && not out of time */ 583 if (can_busy_loop && !need_resched()) { 584 if (!busy_start) { 585 busy_start = busy_loop_current_time(); 586 continue; 587 } 588 if (!busy_loop_timeout(busy_start)) 589 continue; 590 } 591 busy_flag = 0; 592 593 /* 594 * If this is the first loop and we have a timeout 595 * given, then we convert to ktime_t and set the to 596 * pointer to the expiry value. 597 */ 598 if (end_time && !to) { 599 expire = timespec64_to_ktime(*end_time); 600 to = &expire; 601 } 602 603 if (!poll_schedule_timeout(&table, TASK_INTERRUPTIBLE, 604 to, slack)) 605 timed_out = 1; 606 } 607 608 poll_freewait(&table); 609 610 return retval; 611 } 612 613 /* 614 * We can actually return ERESTARTSYS instead of EINTR, but I'd 615 * like to be certain this leads to no problems. So I return 616 * EINTR just for safety. 617 * 618 * Update: ERESTARTSYS breaks at least the xview clock binary, so 619 * I'm trying ERESTARTNOHAND which restart only when you want to. 620 */ 621 int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp, 622 fd_set __user *exp, struct timespec64 *end_time) 623 { 624 fd_set_bits fds; 625 void *bits; 626 int ret, max_fds; 627 size_t size, alloc_size; 628 struct fdtable *fdt; 629 /* Allocate small arguments on the stack to save memory and be faster */ 630 long stack_fds[SELECT_STACK_ALLOC/sizeof(long)]; 631 632 ret = -EINVAL; 633 if (n < 0) 634 goto out_nofds; 635 636 /* max_fds can increase, so grab it once to avoid race */ 637 rcu_read_lock(); 638 fdt = files_fdtable(current->files); 639 max_fds = fdt->max_fds; 640 rcu_read_unlock(); 641 if (n > max_fds) 642 n = max_fds; 643 644 /* 645 * We need 6 bitmaps (in/out/ex for both incoming and outgoing), 646 * since we used fdset we need to allocate memory in units of 647 * long-words. 648 */ 649 size = FDS_BYTES(n); 650 bits = stack_fds; 651 if (size > sizeof(stack_fds) / 6) { 652 /* Not enough space in on-stack array; must use kmalloc */ 653 ret = -ENOMEM; 654 if (size > (SIZE_MAX / 6)) 655 goto out_nofds; 656 657 alloc_size = 6 * size; 658 bits = kvmalloc(alloc_size, GFP_KERNEL); 659 if (!bits) 660 goto out_nofds; 661 } 662 fds.in = bits; 663 fds.out = bits + size; 664 fds.ex = bits + 2*size; 665 fds.res_in = bits + 3*size; 666 fds.res_out = bits + 4*size; 667 fds.res_ex = bits + 5*size; 668 669 if ((ret = get_fd_set(n, inp, fds.in)) || 670 (ret = get_fd_set(n, outp, fds.out)) || 671 (ret = get_fd_set(n, exp, fds.ex))) 672 goto out; 673 zero_fd_set(n, fds.res_in); 674 zero_fd_set(n, fds.res_out); 675 zero_fd_set(n, fds.res_ex); 676 677 ret = do_select(n, &fds, end_time); 678 679 if (ret < 0) 680 goto out; 681 if (!ret) { 682 ret = -ERESTARTNOHAND; 683 if (signal_pending(current)) 684 goto out; 685 ret = 0; 686 } 687 688 if (set_fd_set(n, inp, fds.res_in) || 689 set_fd_set(n, outp, fds.res_out) || 690 set_fd_set(n, exp, fds.res_ex)) 691 ret = -EFAULT; 692 693 out: 694 if (bits != stack_fds) 695 kvfree(bits); 696 out_nofds: 697 return ret; 698 } 699 700 static int kern_select(int n, fd_set __user *inp, fd_set __user *outp, 701 fd_set __user *exp, struct __kernel_old_timeval __user *tvp) 702 { 703 struct timespec64 end_time, *to = NULL; 704 struct __kernel_old_timeval tv; 705 int ret; 706 707 if (tvp) { 708 if (copy_from_user(&tv, tvp, sizeof(tv))) 709 return -EFAULT; 710 711 to = &end_time; 712 if (poll_select_set_timeout(to, 713 tv.tv_sec + (tv.tv_usec / USEC_PER_SEC), 714 (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC)) 715 return -EINVAL; 716 } 717 718 ret = core_sys_select(n, inp, outp, exp, to); 719 return poll_select_finish(&end_time, tvp, PT_TIMEVAL, ret); 720 } 721 722 SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp, 723 fd_set __user *, exp, struct __kernel_old_timeval __user *, tvp) 724 { 725 return kern_select(n, inp, outp, exp, tvp); 726 } 727 728 static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, 729 fd_set __user *exp, void __user *tsp, 730 const sigset_t __user *sigmask, size_t sigsetsize, 731 enum poll_time_type type) 732 { 733 struct timespec64 ts, end_time, *to = NULL; 734 int ret; 735 736 if (tsp) { 737 switch (type) { 738 case PT_TIMESPEC: 739 if (get_timespec64(&ts, tsp)) 740 return -EFAULT; 741 break; 742 case PT_OLD_TIMESPEC: 743 if (get_old_timespec32(&ts, tsp)) 744 return -EFAULT; 745 break; 746 default: 747 BUG(); 748 } 749 750 to = &end_time; 751 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 752 return -EINVAL; 753 } 754 755 ret = set_user_sigmask(sigmask, sigsetsize); 756 if (ret) 757 return ret; 758 759 ret = core_sys_select(n, inp, outp, exp, to); 760 return poll_select_finish(&end_time, tsp, type, ret); 761 } 762 763 /* 764 * Most architectures can't handle 7-argument syscalls. So we provide a 765 * 6-argument version where the sixth argument is a pointer to a structure 766 * which has a pointer to the sigset_t itself followed by a size_t containing 767 * the sigset size. 768 */ 769 struct sigset_argpack { 770 sigset_t __user *p; 771 size_t size; 772 }; 773 774 static inline int get_sigset_argpack(struct sigset_argpack *to, 775 struct sigset_argpack __user *from) 776 { 777 // the path is hot enough for overhead of copy_from_user() to matter 778 if (from) { 779 if (can_do_masked_user_access()) 780 from = masked_user_access_begin(from); 781 else if (!user_read_access_begin(from, sizeof(*from))) 782 return -EFAULT; 783 unsafe_get_user(to->p, &from->p, Efault); 784 unsafe_get_user(to->size, &from->size, Efault); 785 user_read_access_end(); 786 } 787 return 0; 788 Efault: 789 user_access_end(); 790 return -EFAULT; 791 } 792 793 SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp, 794 fd_set __user *, exp, struct __kernel_timespec __user *, tsp, 795 void __user *, sig) 796 { 797 struct sigset_argpack x = {NULL, 0}; 798 799 if (get_sigset_argpack(&x, sig)) 800 return -EFAULT; 801 802 return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC); 803 } 804 805 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) 806 807 SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *, outp, 808 fd_set __user *, exp, struct old_timespec32 __user *, tsp, 809 void __user *, sig) 810 { 811 struct sigset_argpack x = {NULL, 0}; 812 813 if (get_sigset_argpack(&x, sig)) 814 return -EFAULT; 815 816 return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC); 817 } 818 819 #endif 820 821 #ifdef __ARCH_WANT_SYS_OLD_SELECT 822 struct sel_arg_struct { 823 unsigned long n; 824 fd_set __user *inp, *outp, *exp; 825 struct __kernel_old_timeval __user *tvp; 826 }; 827 828 SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg) 829 { 830 struct sel_arg_struct a; 831 832 if (copy_from_user(&a, arg, sizeof(a))) 833 return -EFAULT; 834 return kern_select(a.n, a.inp, a.outp, a.exp, a.tvp); 835 } 836 #endif 837 838 struct poll_list { 839 struct poll_list *next; 840 unsigned int len; 841 struct pollfd entries[] __counted_by(len); 842 }; 843 844 #define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd)) 845 846 /* 847 * Fish for pollable events on the pollfd->fd file descriptor. We're only 848 * interested in events matching the pollfd->events mask, and the result 849 * matching that mask is both recorded in pollfd->revents and returned. The 850 * pwait poll_table will be used by the fd-provided poll handler for waiting, 851 * if pwait->_qproc is non-NULL. 852 */ 853 static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait, 854 bool *can_busy_poll, 855 __poll_t busy_flag) 856 { 857 int fd = pollfd->fd; 858 __poll_t mask, filter; 859 860 if (fd < 0) 861 return 0; 862 863 CLASS(fd, f)(fd); 864 if (fd_empty(f)) 865 return EPOLLNVAL; 866 867 /* userland u16 ->events contains POLL... bitmap */ 868 filter = demangle_poll(pollfd->events) | EPOLLERR | EPOLLHUP; 869 pwait->_key = filter | busy_flag; 870 mask = vfs_poll(fd_file(f), pwait); 871 if (mask & busy_flag) 872 *can_busy_poll = true; 873 return mask & filter; /* Mask out unneeded events. */ 874 } 875 876 static int do_poll(struct poll_list *list, struct poll_wqueues *wait, 877 struct timespec64 *end_time) 878 { 879 poll_table* pt = &wait->pt; 880 ktime_t expire, *to = NULL; 881 int timed_out = 0, count = 0; 882 u64 slack = 0; 883 __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; 884 unsigned long busy_start = 0; 885 886 /* Optimise the no-wait case */ 887 if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { 888 pt->_qproc = NULL; 889 timed_out = 1; 890 } 891 892 if (end_time && !timed_out) 893 slack = select_estimate_accuracy(end_time); 894 895 for (;;) { 896 struct poll_list *walk; 897 bool can_busy_loop = false; 898 899 for (walk = list; walk != NULL; walk = walk->next) { 900 struct pollfd * pfd, * pfd_end; 901 902 pfd = walk->entries; 903 pfd_end = pfd + walk->len; 904 for (; pfd != pfd_end; pfd++) { 905 __poll_t mask; 906 /* 907 * Fish for events. If we found one, record it 908 * and kill poll_table->_qproc, so we don't 909 * needlessly register any other waiters after 910 * this. They'll get immediately deregistered 911 * when we break out and return. 912 */ 913 mask = do_pollfd(pfd, pt, &can_busy_loop, busy_flag); 914 pfd->revents = mangle_poll(mask); 915 if (mask) { 916 count++; 917 pt->_qproc = NULL; 918 /* found something, stop busy polling */ 919 busy_flag = 0; 920 can_busy_loop = false; 921 } 922 } 923 } 924 /* 925 * All waiters have already been registered, so don't provide 926 * a poll_table->_qproc to them on the next loop iteration. 927 */ 928 pt->_qproc = NULL; 929 if (!count) { 930 count = wait->error; 931 if (signal_pending(current)) 932 count = -ERESTARTNOHAND; 933 } 934 if (count || timed_out) 935 break; 936 937 /* only if found POLL_BUSY_LOOP sockets && not out of time */ 938 if (can_busy_loop && !need_resched()) { 939 if (!busy_start) { 940 busy_start = busy_loop_current_time(); 941 continue; 942 } 943 if (!busy_loop_timeout(busy_start)) 944 continue; 945 } 946 busy_flag = 0; 947 948 /* 949 * If this is the first loop and we have a timeout 950 * given, then we convert to ktime_t and set the to 951 * pointer to the expiry value. 952 */ 953 if (end_time && !to) { 954 expire = timespec64_to_ktime(*end_time); 955 to = &expire; 956 } 957 958 if (!poll_schedule_timeout(wait, TASK_INTERRUPTIBLE, to, slack)) 959 timed_out = 1; 960 } 961 return count; 962 } 963 964 #define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list)) / \ 965 sizeof(struct pollfd)) 966 967 static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, 968 struct timespec64 *end_time) 969 { 970 struct poll_wqueues table; 971 int err = -EFAULT, fdcount; 972 /* Allocate small arguments on the stack to save memory and be 973 faster - use long to make sure the buffer is aligned properly 974 on 64 bit archs to avoid unaligned access */ 975 long stack_pps[POLL_STACK_ALLOC/sizeof(long)]; 976 struct poll_list *const head = (struct poll_list *)stack_pps; 977 struct poll_list *walk = head; 978 unsigned int todo = nfds; 979 unsigned int len; 980 981 if (nfds > rlimit(RLIMIT_NOFILE)) 982 return -EINVAL; 983 984 len = min_t(unsigned int, nfds, N_STACK_PPS); 985 for (;;) { 986 walk->next = NULL; 987 walk->len = len; 988 if (!len) 989 break; 990 991 if (copy_from_user(walk->entries, ufds + nfds-todo, 992 sizeof(struct pollfd) * walk->len)) 993 goto out_fds; 994 995 if (walk->len >= todo) 996 break; 997 todo -= walk->len; 998 999 len = min(todo, POLLFD_PER_PAGE); 1000 walk = walk->next = kmalloc(struct_size(walk, entries, len), 1001 GFP_KERNEL); 1002 if (!walk) { 1003 err = -ENOMEM; 1004 goto out_fds; 1005 } 1006 } 1007 1008 poll_initwait(&table); 1009 fdcount = do_poll(head, &table, end_time); 1010 poll_freewait(&table); 1011 1012 if (!user_write_access_begin(ufds, nfds * sizeof(*ufds))) 1013 goto out_fds; 1014 1015 for (walk = head; walk; walk = walk->next) { 1016 struct pollfd *fds = walk->entries; 1017 unsigned int j; 1018 1019 for (j = walk->len; j; fds++, ufds++, j--) 1020 unsafe_put_user(fds->revents, &ufds->revents, Efault); 1021 } 1022 user_write_access_end(); 1023 1024 err = fdcount; 1025 out_fds: 1026 walk = head->next; 1027 while (walk) { 1028 struct poll_list *pos = walk; 1029 walk = walk->next; 1030 kfree(pos); 1031 } 1032 1033 return err; 1034 1035 Efault: 1036 user_write_access_end(); 1037 err = -EFAULT; 1038 goto out_fds; 1039 } 1040 1041 static long do_restart_poll(struct restart_block *restart_block) 1042 { 1043 struct pollfd __user *ufds = restart_block->poll.ufds; 1044 int nfds = restart_block->poll.nfds; 1045 struct timespec64 *to = NULL, end_time; 1046 int ret; 1047 1048 if (restart_block->poll.has_timeout) { 1049 end_time.tv_sec = restart_block->poll.tv_sec; 1050 end_time.tv_nsec = restart_block->poll.tv_nsec; 1051 to = &end_time; 1052 } 1053 1054 ret = do_sys_poll(ufds, nfds, to); 1055 1056 if (ret == -ERESTARTNOHAND) 1057 ret = set_restart_fn(restart_block, do_restart_poll); 1058 1059 return ret; 1060 } 1061 1062 SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, 1063 int, timeout_msecs) 1064 { 1065 struct timespec64 end_time, *to = NULL; 1066 int ret; 1067 1068 if (timeout_msecs >= 0) { 1069 to = &end_time; 1070 poll_select_set_timeout(to, timeout_msecs / MSEC_PER_SEC, 1071 NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC)); 1072 } 1073 1074 ret = do_sys_poll(ufds, nfds, to); 1075 1076 if (ret == -ERESTARTNOHAND) { 1077 struct restart_block *restart_block; 1078 1079 restart_block = ¤t->restart_block; 1080 restart_block->poll.ufds = ufds; 1081 restart_block->poll.nfds = nfds; 1082 1083 if (timeout_msecs >= 0) { 1084 restart_block->poll.tv_sec = end_time.tv_sec; 1085 restart_block->poll.tv_nsec = end_time.tv_nsec; 1086 restart_block->poll.has_timeout = 1; 1087 } else 1088 restart_block->poll.has_timeout = 0; 1089 1090 ret = set_restart_fn(restart_block, do_restart_poll); 1091 } 1092 return ret; 1093 } 1094 1095 SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, 1096 struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask, 1097 size_t, sigsetsize) 1098 { 1099 struct timespec64 ts, end_time, *to = NULL; 1100 int ret; 1101 1102 if (tsp) { 1103 if (get_timespec64(&ts, tsp)) 1104 return -EFAULT; 1105 1106 to = &end_time; 1107 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1108 return -EINVAL; 1109 } 1110 1111 ret = set_user_sigmask(sigmask, sigsetsize); 1112 if (ret) 1113 return ret; 1114 1115 ret = do_sys_poll(ufds, nfds, to); 1116 return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); 1117 } 1118 1119 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) 1120 1121 SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, 1122 struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask, 1123 size_t, sigsetsize) 1124 { 1125 struct timespec64 ts, end_time, *to = NULL; 1126 int ret; 1127 1128 if (tsp) { 1129 if (get_old_timespec32(&ts, tsp)) 1130 return -EFAULT; 1131 1132 to = &end_time; 1133 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1134 return -EINVAL; 1135 } 1136 1137 ret = set_user_sigmask(sigmask, sigsetsize); 1138 if (ret) 1139 return ret; 1140 1141 ret = do_sys_poll(ufds, nfds, to); 1142 return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); 1143 } 1144 #endif 1145 1146 #ifdef CONFIG_COMPAT 1147 #define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t)) 1148 1149 /* 1150 * Ooo, nasty. We need here to frob 32-bit unsigned longs to 1151 * 64-bit unsigned longs. 1152 */ 1153 static 1154 int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, 1155 unsigned long *fdset) 1156 { 1157 if (ufdset) { 1158 return compat_get_bitmap(fdset, ufdset, nr); 1159 } else { 1160 zero_fd_set(nr, fdset); 1161 return 0; 1162 } 1163 } 1164 1165 static 1166 int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, 1167 unsigned long *fdset) 1168 { 1169 if (!ufdset) 1170 return 0; 1171 return compat_put_bitmap(ufdset, fdset, nr); 1172 } 1173 1174 1175 /* 1176 * This is a virtual copy of sys_select from fs/select.c and probably 1177 * should be compared to it from time to time 1178 */ 1179 1180 /* 1181 * We can actually return ERESTARTSYS instead of EINTR, but I'd 1182 * like to be certain this leads to no problems. So I return 1183 * EINTR just for safety. 1184 * 1185 * Update: ERESTARTSYS breaks at least the xview clock binary, so 1186 * I'm trying ERESTARTNOHAND which restart only when you want to. 1187 */ 1188 static int compat_core_sys_select(int n, compat_ulong_t __user *inp, 1189 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1190 struct timespec64 *end_time) 1191 { 1192 fd_set_bits fds; 1193 void *bits; 1194 int size, max_fds, ret = -EINVAL; 1195 struct fdtable *fdt; 1196 long stack_fds[SELECT_STACK_ALLOC/sizeof(long)]; 1197 1198 if (n < 0) 1199 goto out_nofds; 1200 1201 /* max_fds can increase, so grab it once to avoid race */ 1202 rcu_read_lock(); 1203 fdt = files_fdtable(current->files); 1204 max_fds = fdt->max_fds; 1205 rcu_read_unlock(); 1206 if (n > max_fds) 1207 n = max_fds; 1208 1209 /* 1210 * We need 6 bitmaps (in/out/ex for both incoming and outgoing), 1211 * since we used fdset we need to allocate memory in units of 1212 * long-words. 1213 */ 1214 size = FDS_BYTES(n); 1215 bits = stack_fds; 1216 if (size > sizeof(stack_fds) / 6) { 1217 bits = kmalloc_array(6, size, GFP_KERNEL); 1218 ret = -ENOMEM; 1219 if (!bits) 1220 goto out_nofds; 1221 } 1222 fds.in = (unsigned long *) bits; 1223 fds.out = (unsigned long *) (bits + size); 1224 fds.ex = (unsigned long *) (bits + 2*size); 1225 fds.res_in = (unsigned long *) (bits + 3*size); 1226 fds.res_out = (unsigned long *) (bits + 4*size); 1227 fds.res_ex = (unsigned long *) (bits + 5*size); 1228 1229 if ((ret = compat_get_fd_set(n, inp, fds.in)) || 1230 (ret = compat_get_fd_set(n, outp, fds.out)) || 1231 (ret = compat_get_fd_set(n, exp, fds.ex))) 1232 goto out; 1233 zero_fd_set(n, fds.res_in); 1234 zero_fd_set(n, fds.res_out); 1235 zero_fd_set(n, fds.res_ex); 1236 1237 ret = do_select(n, &fds, end_time); 1238 1239 if (ret < 0) 1240 goto out; 1241 if (!ret) { 1242 ret = -ERESTARTNOHAND; 1243 if (signal_pending(current)) 1244 goto out; 1245 ret = 0; 1246 } 1247 1248 if (compat_set_fd_set(n, inp, fds.res_in) || 1249 compat_set_fd_set(n, outp, fds.res_out) || 1250 compat_set_fd_set(n, exp, fds.res_ex)) 1251 ret = -EFAULT; 1252 out: 1253 if (bits != stack_fds) 1254 kfree(bits); 1255 out_nofds: 1256 return ret; 1257 } 1258 1259 static int do_compat_select(int n, compat_ulong_t __user *inp, 1260 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1261 struct old_timeval32 __user *tvp) 1262 { 1263 struct timespec64 end_time, *to = NULL; 1264 struct old_timeval32 tv; 1265 int ret; 1266 1267 if (tvp) { 1268 if (copy_from_user(&tv, tvp, sizeof(tv))) 1269 return -EFAULT; 1270 1271 to = &end_time; 1272 if (poll_select_set_timeout(to, 1273 tv.tv_sec + (tv.tv_usec / USEC_PER_SEC), 1274 (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC)) 1275 return -EINVAL; 1276 } 1277 1278 ret = compat_core_sys_select(n, inp, outp, exp, to); 1279 return poll_select_finish(&end_time, tvp, PT_OLD_TIMEVAL, ret); 1280 } 1281 1282 COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp, 1283 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1284 struct old_timeval32 __user *, tvp) 1285 { 1286 return do_compat_select(n, inp, outp, exp, tvp); 1287 } 1288 1289 struct compat_sel_arg_struct { 1290 compat_ulong_t n; 1291 compat_uptr_t inp; 1292 compat_uptr_t outp; 1293 compat_uptr_t exp; 1294 compat_uptr_t tvp; 1295 }; 1296 1297 COMPAT_SYSCALL_DEFINE1(old_select, struct compat_sel_arg_struct __user *, arg) 1298 { 1299 struct compat_sel_arg_struct a; 1300 1301 if (copy_from_user(&a, arg, sizeof(a))) 1302 return -EFAULT; 1303 return do_compat_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp), 1304 compat_ptr(a.exp), compat_ptr(a.tvp)); 1305 } 1306 1307 static long do_compat_pselect(int n, compat_ulong_t __user *inp, 1308 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1309 void __user *tsp, compat_sigset_t __user *sigmask, 1310 compat_size_t sigsetsize, enum poll_time_type type) 1311 { 1312 struct timespec64 ts, end_time, *to = NULL; 1313 int ret; 1314 1315 if (tsp) { 1316 switch (type) { 1317 case PT_OLD_TIMESPEC: 1318 if (get_old_timespec32(&ts, tsp)) 1319 return -EFAULT; 1320 break; 1321 case PT_TIMESPEC: 1322 if (get_timespec64(&ts, tsp)) 1323 return -EFAULT; 1324 break; 1325 default: 1326 BUG(); 1327 } 1328 1329 to = &end_time; 1330 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1331 return -EINVAL; 1332 } 1333 1334 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1335 if (ret) 1336 return ret; 1337 1338 ret = compat_core_sys_select(n, inp, outp, exp, to); 1339 return poll_select_finish(&end_time, tsp, type, ret); 1340 } 1341 1342 struct compat_sigset_argpack { 1343 compat_uptr_t p; 1344 compat_size_t size; 1345 }; 1346 static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to, 1347 struct compat_sigset_argpack __user *from) 1348 { 1349 if (from) { 1350 if (!user_read_access_begin(from, sizeof(*from))) 1351 return -EFAULT; 1352 unsafe_get_user(to->p, &from->p, Efault); 1353 unsafe_get_user(to->size, &from->size, Efault); 1354 user_read_access_end(); 1355 } 1356 return 0; 1357 Efault: 1358 user_access_end(); 1359 return -EFAULT; 1360 } 1361 1362 COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp, 1363 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1364 struct __kernel_timespec __user *, tsp, void __user *, sig) 1365 { 1366 struct compat_sigset_argpack x = {0, 0}; 1367 1368 if (get_compat_sigset_argpack(&x, sig)) 1369 return -EFAULT; 1370 1371 return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), 1372 x.size, PT_TIMESPEC); 1373 } 1374 1375 #if defined(CONFIG_COMPAT_32BIT_TIME) 1376 1377 COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp, 1378 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1379 struct old_timespec32 __user *, tsp, void __user *, sig) 1380 { 1381 struct compat_sigset_argpack x = {0, 0}; 1382 1383 if (get_compat_sigset_argpack(&x, sig)) 1384 return -EFAULT; 1385 1386 return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), 1387 x.size, PT_OLD_TIMESPEC); 1388 } 1389 1390 #endif 1391 1392 #if defined(CONFIG_COMPAT_32BIT_TIME) 1393 COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, 1394 unsigned int, nfds, struct old_timespec32 __user *, tsp, 1395 const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize) 1396 { 1397 struct timespec64 ts, end_time, *to = NULL; 1398 int ret; 1399 1400 if (tsp) { 1401 if (get_old_timespec32(&ts, tsp)) 1402 return -EFAULT; 1403 1404 to = &end_time; 1405 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1406 return -EINVAL; 1407 } 1408 1409 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1410 if (ret) 1411 return ret; 1412 1413 ret = do_sys_poll(ufds, nfds, to); 1414 return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); 1415 } 1416 #endif 1417 1418 /* New compat syscall for 64 bit time_t*/ 1419 COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds, 1420 unsigned int, nfds, struct __kernel_timespec __user *, tsp, 1421 const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize) 1422 { 1423 struct timespec64 ts, end_time, *to = NULL; 1424 int ret; 1425 1426 if (tsp) { 1427 if (get_timespec64(&ts, tsp)) 1428 return -EFAULT; 1429 1430 to = &end_time; 1431 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1432 return -EINVAL; 1433 } 1434 1435 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1436 if (ret) 1437 return ret; 1438 1439 ret = do_sys_poll(ufds, nfds, to); 1440 return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); 1441 } 1442 1443 #endif 1444