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 81 /* 82 * Realtime tasks get a slack of 0 for obvious reasons. 83 */ 84 85 if (rt_task(current)) 86 return 0; 87 88 ktime_get_ts64(&now); 89 now = timespec64_sub(*tv, now); 90 ret = __estimate_accuracy(&now); 91 if (ret < current->timer_slack_ns) 92 return current->timer_slack_ns; 93 return ret; 94 } 95 96 97 98 struct poll_table_page { 99 struct poll_table_page * next; 100 struct poll_table_entry * entry; 101 struct poll_table_entry entries[]; 102 }; 103 104 #define POLL_TABLE_FULL(table) \ 105 ((unsigned long)((table)->entry+1) > PAGE_SIZE + (unsigned long)(table)) 106 107 /* 108 * Ok, Peter made a complicated, but straightforward multiple_wait() function. 109 * I have rewritten this, taking some shortcuts: This code may not be easy to 110 * follow, but it should be free of race-conditions, and it's practical. If you 111 * understand what I'm doing here, then you understand how the linux 112 * sleep/wakeup mechanism works. 113 * 114 * Two very simple procedures, poll_wait() and poll_freewait() make all the 115 * work. poll_wait() is an inline-function defined in <linux/poll.h>, 116 * as all select/poll functions have to call it to add an entry to the 117 * poll table. 118 */ 119 static void __pollwait(struct file *filp, wait_queue_head_t *wait_address, 120 poll_table *p); 121 122 void poll_initwait(struct poll_wqueues *pwq) 123 { 124 init_poll_funcptr(&pwq->pt, __pollwait); 125 pwq->polling_task = current; 126 pwq->triggered = 0; 127 pwq->error = 0; 128 pwq->table = NULL; 129 pwq->inline_index = 0; 130 } 131 EXPORT_SYMBOL(poll_initwait); 132 133 static void free_poll_entry(struct poll_table_entry *entry) 134 { 135 remove_wait_queue(entry->wait_address, &entry->wait); 136 fput(entry->filp); 137 } 138 139 void poll_freewait(struct poll_wqueues *pwq) 140 { 141 struct poll_table_page * p = pwq->table; 142 int i; 143 for (i = 0; i < pwq->inline_index; i++) 144 free_poll_entry(pwq->inline_entries + i); 145 while (p) { 146 struct poll_table_entry * entry; 147 struct poll_table_page *old; 148 149 entry = p->entry; 150 do { 151 entry--; 152 free_poll_entry(entry); 153 } while (entry > p->entries); 154 old = p; 155 p = p->next; 156 free_page((unsigned long) old); 157 } 158 } 159 EXPORT_SYMBOL(poll_freewait); 160 161 static struct poll_table_entry *poll_get_entry(struct poll_wqueues *p) 162 { 163 struct poll_table_page *table = p->table; 164 165 if (p->inline_index < N_INLINE_POLL_ENTRIES) 166 return p->inline_entries + p->inline_index++; 167 168 if (!table || POLL_TABLE_FULL(table)) { 169 struct poll_table_page *new_table; 170 171 new_table = (struct poll_table_page *) __get_free_page(GFP_KERNEL); 172 if (!new_table) { 173 p->error = -ENOMEM; 174 return NULL; 175 } 176 new_table->entry = new_table->entries; 177 new_table->next = table; 178 p->table = new_table; 179 table = new_table; 180 } 181 182 return table->entry++; 183 } 184 185 static int __pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) 186 { 187 struct poll_wqueues *pwq = wait->private; 188 DECLARE_WAITQUEUE(dummy_wait, pwq->polling_task); 189 190 /* 191 * Although this function is called under waitqueue lock, LOCK 192 * doesn't imply write barrier and the users expect write 193 * barrier semantics on wakeup functions. The following 194 * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up() 195 * and is paired with smp_store_mb() in poll_schedule_timeout. 196 */ 197 smp_wmb(); 198 pwq->triggered = 1; 199 200 /* 201 * Perform the default wake up operation using a dummy 202 * waitqueue. 203 * 204 * TODO: This is hacky but there currently is no interface to 205 * pass in @sync. @sync is scheduled to be removed and once 206 * that happens, wake_up_process() can be used directly. 207 */ 208 return default_wake_function(&dummy_wait, mode, sync, key); 209 } 210 211 static int pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) 212 { 213 struct poll_table_entry *entry; 214 215 entry = container_of(wait, struct poll_table_entry, wait); 216 if (key && !(key_to_poll(key) & entry->key)) 217 return 0; 218 return __pollwake(wait, mode, sync, key); 219 } 220 221 /* Add a new entry */ 222 static void __pollwait(struct file *filp, wait_queue_head_t *wait_address, 223 poll_table *p) 224 { 225 struct poll_wqueues *pwq = container_of(p, struct poll_wqueues, pt); 226 struct poll_table_entry *entry = poll_get_entry(pwq); 227 if (!entry) 228 return; 229 entry->filp = get_file(filp); 230 entry->wait_address = wait_address; 231 entry->key = p->_key; 232 init_waitqueue_func_entry(&entry->wait, pollwake); 233 entry->wait.private = pwq; 234 add_wait_queue(wait_address, &entry->wait); 235 } 236 237 static int poll_schedule_timeout(struct poll_wqueues *pwq, int state, 238 ktime_t *expires, unsigned long slack) 239 { 240 int rc = -EINTR; 241 242 set_current_state(state); 243 if (!pwq->triggered) 244 rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS); 245 __set_current_state(TASK_RUNNING); 246 247 /* 248 * Prepare for the next iteration. 249 * 250 * The following smp_store_mb() serves two purposes. First, it's 251 * the counterpart rmb of the wmb in pollwake() such that data 252 * written before wake up is always visible after wake up. 253 * Second, the full barrier guarantees that triggered clearing 254 * doesn't pass event check of the next iteration. Note that 255 * this problem doesn't exist for the first iteration as 256 * add_wait_queue() has full barrier semantics. 257 */ 258 smp_store_mb(pwq->triggered, 0); 259 260 return rc; 261 } 262 263 /** 264 * poll_select_set_timeout - helper function to setup the timeout value 265 * @to: pointer to timespec64 variable for the final timeout 266 * @sec: seconds (from user space) 267 * @nsec: nanoseconds (from user space) 268 * 269 * Note, we do not use a timespec for the user space value here, That 270 * way we can use the function for timeval and compat interfaces as well. 271 * 272 * Returns -EINVAL if sec/nsec are not normalized. Otherwise 0. 273 */ 274 int poll_select_set_timeout(struct timespec64 *to, time64_t sec, long nsec) 275 { 276 struct timespec64 ts = {.tv_sec = sec, .tv_nsec = nsec}; 277 278 if (!timespec64_valid(&ts)) 279 return -EINVAL; 280 281 /* Optimize for the zero timeout value here */ 282 if (!sec && !nsec) { 283 to->tv_sec = to->tv_nsec = 0; 284 } else { 285 ktime_get_ts64(to); 286 *to = timespec64_add_safe(*to, ts); 287 } 288 return 0; 289 } 290 291 enum poll_time_type { 292 PT_TIMEVAL = 0, 293 PT_OLD_TIMEVAL = 1, 294 PT_TIMESPEC = 2, 295 PT_OLD_TIMESPEC = 3, 296 }; 297 298 static int poll_select_finish(struct timespec64 *end_time, 299 void __user *p, 300 enum poll_time_type pt_type, int ret) 301 { 302 struct timespec64 rts; 303 304 restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); 305 306 if (!p) 307 return ret; 308 309 if (current->personality & STICKY_TIMEOUTS) 310 goto sticky; 311 312 /* No update for zero timeout */ 313 if (!end_time->tv_sec && !end_time->tv_nsec) 314 return ret; 315 316 ktime_get_ts64(&rts); 317 rts = timespec64_sub(*end_time, rts); 318 if (rts.tv_sec < 0) 319 rts.tv_sec = rts.tv_nsec = 0; 320 321 322 switch (pt_type) { 323 case PT_TIMEVAL: 324 { 325 struct __kernel_old_timeval rtv; 326 327 if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec)) 328 memset(&rtv, 0, sizeof(rtv)); 329 rtv.tv_sec = rts.tv_sec; 330 rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; 331 if (!copy_to_user(p, &rtv, sizeof(rtv))) 332 return ret; 333 } 334 break; 335 case PT_OLD_TIMEVAL: 336 { 337 struct old_timeval32 rtv; 338 339 rtv.tv_sec = rts.tv_sec; 340 rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; 341 if (!copy_to_user(p, &rtv, sizeof(rtv))) 342 return ret; 343 } 344 break; 345 case PT_TIMESPEC: 346 if (!put_timespec64(&rts, p)) 347 return ret; 348 break; 349 case PT_OLD_TIMESPEC: 350 if (!put_old_timespec32(&rts, p)) 351 return ret; 352 break; 353 default: 354 BUG(); 355 } 356 /* 357 * If an application puts its timeval in read-only memory, we 358 * don't want the Linux-specific update to the timeval to 359 * cause a fault after the select has completed 360 * successfully. However, because we're not updating the 361 * timeval, we can't restart the system call. 362 */ 363 364 sticky: 365 if (ret == -ERESTARTNOHAND) 366 ret = -EINTR; 367 return ret; 368 } 369 370 /* 371 * Scalable version of the fd_set. 372 */ 373 374 typedef struct { 375 unsigned long *in, *out, *ex; 376 unsigned long *res_in, *res_out, *res_ex; 377 } fd_set_bits; 378 379 /* 380 * How many longwords for "nr" bits? 381 */ 382 #define FDS_BITPERLONG (8*sizeof(long)) 383 #define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG) 384 #define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long)) 385 386 /* 387 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned. 388 */ 389 static inline 390 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) 391 { 392 nr = FDS_BYTES(nr); 393 if (ufdset) 394 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0; 395 396 memset(fdset, 0, nr); 397 return 0; 398 } 399 400 static inline unsigned long __must_check 401 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) 402 { 403 if (ufdset) 404 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr)); 405 return 0; 406 } 407 408 static inline 409 void zero_fd_set(unsigned long nr, unsigned long *fdset) 410 { 411 memset(fdset, 0, FDS_BYTES(nr)); 412 } 413 414 #define FDS_IN(fds, n) (fds->in + n) 415 #define FDS_OUT(fds, n) (fds->out + n) 416 #define FDS_EX(fds, n) (fds->ex + n) 417 418 #define BITS(fds, n) (*FDS_IN(fds, n)|*FDS_OUT(fds, n)|*FDS_EX(fds, n)) 419 420 static int max_select_fd(unsigned long n, fd_set_bits *fds) 421 { 422 unsigned long *open_fds; 423 unsigned long set; 424 int max; 425 struct fdtable *fdt; 426 427 /* handle last in-complete long-word first */ 428 set = ~(~0UL << (n & (BITS_PER_LONG-1))); 429 n /= BITS_PER_LONG; 430 fdt = files_fdtable(current->files); 431 open_fds = fdt->open_fds + n; 432 max = 0; 433 if (set) { 434 set &= BITS(fds, n); 435 if (set) { 436 if (!(set & ~*open_fds)) 437 goto get_max; 438 return -EBADF; 439 } 440 } 441 while (n) { 442 open_fds--; 443 n--; 444 set = BITS(fds, n); 445 if (!set) 446 continue; 447 if (set & ~*open_fds) 448 return -EBADF; 449 if (max) 450 continue; 451 get_max: 452 do { 453 max++; 454 set >>= 1; 455 } while (set); 456 max += n * BITS_PER_LONG; 457 } 458 459 return max; 460 } 461 462 #define POLLIN_SET (EPOLLRDNORM | EPOLLRDBAND | EPOLLIN | EPOLLHUP | EPOLLERR) 463 #define POLLOUT_SET (EPOLLWRBAND | EPOLLWRNORM | EPOLLOUT | EPOLLERR) 464 #define POLLEX_SET (EPOLLPRI) 465 466 static inline void wait_key_set(poll_table *wait, unsigned long in, 467 unsigned long out, unsigned long bit, 468 __poll_t ll_flag) 469 { 470 wait->_key = POLLEX_SET | ll_flag; 471 if (in & bit) 472 wait->_key |= POLLIN_SET; 473 if (out & bit) 474 wait->_key |= POLLOUT_SET; 475 } 476 477 static int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time) 478 { 479 ktime_t expire, *to = NULL; 480 struct poll_wqueues table; 481 poll_table *wait; 482 int retval, i, timed_out = 0; 483 u64 slack = 0; 484 __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; 485 unsigned long busy_start = 0; 486 487 rcu_read_lock(); 488 retval = max_select_fd(n, fds); 489 rcu_read_unlock(); 490 491 if (retval < 0) 492 return retval; 493 n = retval; 494 495 poll_initwait(&table); 496 wait = &table.pt; 497 if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { 498 wait->_qproc = NULL; 499 timed_out = 1; 500 } 501 502 if (end_time && !timed_out) 503 slack = select_estimate_accuracy(end_time); 504 505 retval = 0; 506 for (;;) { 507 unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp; 508 bool can_busy_loop = false; 509 510 inp = fds->in; outp = fds->out; exp = fds->ex; 511 rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex; 512 513 for (i = 0; i < n; ++rinp, ++routp, ++rexp) { 514 unsigned long in, out, ex, all_bits, bit = 1, j; 515 unsigned long res_in = 0, res_out = 0, res_ex = 0; 516 __poll_t mask; 517 518 in = *inp++; out = *outp++; ex = *exp++; 519 all_bits = in | out | ex; 520 if (all_bits == 0) { 521 i += BITS_PER_LONG; 522 continue; 523 } 524 525 for (j = 0; j < BITS_PER_LONG; ++j, ++i, bit <<= 1) { 526 struct fd f; 527 if (i >= n) 528 break; 529 if (!(bit & all_bits)) 530 continue; 531 f = fdget(i); 532 if (f.file) { 533 wait_key_set(wait, in, out, bit, 534 busy_flag); 535 mask = vfs_poll(f.file, wait); 536 537 fdput(f); 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 } 567 if (res_in) 568 *rinp = res_in; 569 if (res_out) 570 *routp = res_out; 571 if (res_ex) 572 *rexp = res_ex; 573 cond_resched(); 574 } 575 wait->_qproc = NULL; 576 if (retval || timed_out || signal_pending(current)) 577 break; 578 if (table.error) { 579 retval = table.error; 580 break; 581 } 582 583 /* only if found POLL_BUSY_LOOP sockets && not out of time */ 584 if (can_busy_loop && !need_resched()) { 585 if (!busy_start) { 586 busy_start = busy_loop_current_time(); 587 continue; 588 } 589 if (!busy_loop_timeout(busy_start)) 590 continue; 591 } 592 busy_flag = 0; 593 594 /* 595 * If this is the first loop and we have a timeout 596 * given, then we convert to ktime_t and set the to 597 * pointer to the expiry value. 598 */ 599 if (end_time && !to) { 600 expire = timespec64_to_ktime(*end_time); 601 to = &expire; 602 } 603 604 if (!poll_schedule_timeout(&table, TASK_INTERRUPTIBLE, 605 to, slack)) 606 timed_out = 1; 607 } 608 609 poll_freewait(&table); 610 611 return retval; 612 } 613 614 /* 615 * We can actually return ERESTARTSYS instead of EINTR, but I'd 616 * like to be certain this leads to no problems. So I return 617 * EINTR just for safety. 618 * 619 * Update: ERESTARTSYS breaks at least the xview clock binary, so 620 * I'm trying ERESTARTNOHAND which restart only when you want to. 621 */ 622 int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp, 623 fd_set __user *exp, struct timespec64 *end_time) 624 { 625 fd_set_bits fds; 626 void *bits; 627 int ret, max_fds; 628 size_t size, alloc_size; 629 struct fdtable *fdt; 630 /* Allocate small arguments on the stack to save memory and be faster */ 631 long stack_fds[SELECT_STACK_ALLOC/sizeof(long)]; 632 633 ret = -EINVAL; 634 if (n < 0) 635 goto out_nofds; 636 637 /* max_fds can increase, so grab it once to avoid race */ 638 rcu_read_lock(); 639 fdt = files_fdtable(current->files); 640 max_fds = fdt->max_fds; 641 rcu_read_unlock(); 642 if (n > max_fds) 643 n = max_fds; 644 645 /* 646 * We need 6 bitmaps (in/out/ex for both incoming and outgoing), 647 * since we used fdset we need to allocate memory in units of 648 * long-words. 649 */ 650 size = FDS_BYTES(n); 651 bits = stack_fds; 652 if (size > sizeof(stack_fds) / 6) { 653 /* Not enough space in on-stack array; must use kmalloc */ 654 ret = -ENOMEM; 655 if (size > (SIZE_MAX / 6)) 656 goto out_nofds; 657 658 alloc_size = 6 * size; 659 bits = kvmalloc(alloc_size, GFP_KERNEL); 660 if (!bits) 661 goto out_nofds; 662 } 663 fds.in = bits; 664 fds.out = bits + size; 665 fds.ex = bits + 2*size; 666 fds.res_in = bits + 3*size; 667 fds.res_out = bits + 4*size; 668 fds.res_ex = bits + 5*size; 669 670 if ((ret = get_fd_set(n, inp, fds.in)) || 671 (ret = get_fd_set(n, outp, fds.out)) || 672 (ret = get_fd_set(n, exp, fds.ex))) 673 goto out; 674 zero_fd_set(n, fds.res_in); 675 zero_fd_set(n, fds.res_out); 676 zero_fd_set(n, fds.res_ex); 677 678 ret = do_select(n, &fds, end_time); 679 680 if (ret < 0) 681 goto out; 682 if (!ret) { 683 ret = -ERESTARTNOHAND; 684 if (signal_pending(current)) 685 goto out; 686 ret = 0; 687 } 688 689 if (set_fd_set(n, inp, fds.res_in) || 690 set_fd_set(n, outp, fds.res_out) || 691 set_fd_set(n, exp, fds.res_ex)) 692 ret = -EFAULT; 693 694 out: 695 if (bits != stack_fds) 696 kvfree(bits); 697 out_nofds: 698 return ret; 699 } 700 701 static int kern_select(int n, fd_set __user *inp, fd_set __user *outp, 702 fd_set __user *exp, struct __kernel_old_timeval __user *tvp) 703 { 704 struct timespec64 end_time, *to = NULL; 705 struct __kernel_old_timeval tv; 706 int ret; 707 708 if (tvp) { 709 if (copy_from_user(&tv, tvp, sizeof(tv))) 710 return -EFAULT; 711 712 to = &end_time; 713 if (poll_select_set_timeout(to, 714 tv.tv_sec + (tv.tv_usec / USEC_PER_SEC), 715 (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC)) 716 return -EINVAL; 717 } 718 719 ret = core_sys_select(n, inp, outp, exp, to); 720 return poll_select_finish(&end_time, tvp, PT_TIMEVAL, ret); 721 } 722 723 SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp, 724 fd_set __user *, exp, struct __kernel_old_timeval __user *, tvp) 725 { 726 return kern_select(n, inp, outp, exp, tvp); 727 } 728 729 static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, 730 fd_set __user *exp, void __user *tsp, 731 const sigset_t __user *sigmask, size_t sigsetsize, 732 enum poll_time_type type) 733 { 734 struct timespec64 ts, end_time, *to = NULL; 735 int ret; 736 737 if (tsp) { 738 switch (type) { 739 case PT_TIMESPEC: 740 if (get_timespec64(&ts, tsp)) 741 return -EFAULT; 742 break; 743 case PT_OLD_TIMESPEC: 744 if (get_old_timespec32(&ts, tsp)) 745 return -EFAULT; 746 break; 747 default: 748 BUG(); 749 } 750 751 to = &end_time; 752 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 753 return -EINVAL; 754 } 755 756 ret = set_user_sigmask(sigmask, sigsetsize); 757 if (ret) 758 return ret; 759 760 ret = core_sys_select(n, inp, outp, exp, to); 761 return poll_select_finish(&end_time, tsp, type, ret); 762 } 763 764 /* 765 * Most architectures can't handle 7-argument syscalls. So we provide a 766 * 6-argument version where the sixth argument is a pointer to a structure 767 * which has a pointer to the sigset_t itself followed by a size_t containing 768 * the sigset size. 769 */ 770 struct sigset_argpack { 771 sigset_t __user *p; 772 size_t size; 773 }; 774 775 static inline int get_sigset_argpack(struct sigset_argpack *to, 776 struct sigset_argpack __user *from) 777 { 778 // the path is hot enough for overhead of copy_from_user() to matter 779 if (from) { 780 if (!user_read_access_begin(from, sizeof(*from))) 781 return -EFAULT; 782 unsafe_get_user(to->p, &from->p, Efault); 783 unsafe_get_user(to->size, &from->size, Efault); 784 user_read_access_end(); 785 } 786 return 0; 787 Efault: 788 user_access_end(); 789 return -EFAULT; 790 } 791 792 SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp, 793 fd_set __user *, exp, struct __kernel_timespec __user *, tsp, 794 void __user *, sig) 795 { 796 struct sigset_argpack x = {NULL, 0}; 797 798 if (get_sigset_argpack(&x, sig)) 799 return -EFAULT; 800 801 return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC); 802 } 803 804 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) 805 806 SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *, outp, 807 fd_set __user *, exp, struct old_timespec32 __user *, tsp, 808 void __user *, sig) 809 { 810 struct sigset_argpack x = {NULL, 0}; 811 812 if (get_sigset_argpack(&x, sig)) 813 return -EFAULT; 814 815 return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC); 816 } 817 818 #endif 819 820 #ifdef __ARCH_WANT_SYS_OLD_SELECT 821 struct sel_arg_struct { 822 unsigned long n; 823 fd_set __user *inp, *outp, *exp; 824 struct __kernel_old_timeval __user *tvp; 825 }; 826 827 SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg) 828 { 829 struct sel_arg_struct a; 830 831 if (copy_from_user(&a, arg, sizeof(a))) 832 return -EFAULT; 833 return kern_select(a.n, a.inp, a.outp, a.exp, a.tvp); 834 } 835 #endif 836 837 struct poll_list { 838 struct poll_list *next; 839 int len; 840 struct pollfd entries[]; 841 }; 842 843 #define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd)) 844 845 /* 846 * Fish for pollable events on the pollfd->fd file descriptor. We're only 847 * interested in events matching the pollfd->events mask, and the result 848 * matching that mask is both recorded in pollfd->revents and returned. The 849 * pwait poll_table will be used by the fd-provided poll handler for waiting, 850 * if pwait->_qproc is non-NULL. 851 */ 852 static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait, 853 bool *can_busy_poll, 854 __poll_t busy_flag) 855 { 856 int fd = pollfd->fd; 857 __poll_t mask = 0, filter; 858 struct fd f; 859 860 if (fd < 0) 861 goto out; 862 mask = EPOLLNVAL; 863 f = fdget(fd); 864 if (!f.file) 865 goto out; 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(f.file, pwait); 871 if (mask & busy_flag) 872 *can_busy_poll = true; 873 mask &= filter; /* Mask out unneeded events. */ 874 fdput(f); 875 876 out: 877 /* ... and so does ->revents */ 878 pollfd->revents = mangle_poll(mask); 879 return mask; 880 } 881 882 static int do_poll(struct poll_list *list, struct poll_wqueues *wait, 883 struct timespec64 *end_time) 884 { 885 poll_table* pt = &wait->pt; 886 ktime_t expire, *to = NULL; 887 int timed_out = 0, count = 0; 888 u64 slack = 0; 889 __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; 890 unsigned long busy_start = 0; 891 892 /* Optimise the no-wait case */ 893 if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { 894 pt->_qproc = NULL; 895 timed_out = 1; 896 } 897 898 if (end_time && !timed_out) 899 slack = select_estimate_accuracy(end_time); 900 901 for (;;) { 902 struct poll_list *walk; 903 bool can_busy_loop = false; 904 905 for (walk = list; walk != NULL; walk = walk->next) { 906 struct pollfd * pfd, * pfd_end; 907 908 pfd = walk->entries; 909 pfd_end = pfd + walk->len; 910 for (; pfd != pfd_end; pfd++) { 911 /* 912 * Fish for events. If we found one, record it 913 * and kill poll_table->_qproc, so we don't 914 * needlessly register any other waiters after 915 * this. They'll get immediately deregistered 916 * when we break out and return. 917 */ 918 if (do_pollfd(pfd, pt, &can_busy_loop, 919 busy_flag)) { 920 count++; 921 pt->_qproc = NULL; 922 /* found something, stop busy polling */ 923 busy_flag = 0; 924 can_busy_loop = false; 925 } 926 } 927 } 928 /* 929 * All waiters have already been registered, so don't provide 930 * a poll_table->_qproc to them on the next loop iteration. 931 */ 932 pt->_qproc = NULL; 933 if (!count) { 934 count = wait->error; 935 if (signal_pending(current)) 936 count = -ERESTARTNOHAND; 937 } 938 if (count || timed_out) 939 break; 940 941 /* only if found POLL_BUSY_LOOP sockets && not out of time */ 942 if (can_busy_loop && !need_resched()) { 943 if (!busy_start) { 944 busy_start = busy_loop_current_time(); 945 continue; 946 } 947 if (!busy_loop_timeout(busy_start)) 948 continue; 949 } 950 busy_flag = 0; 951 952 /* 953 * If this is the first loop and we have a timeout 954 * given, then we convert to ktime_t and set the to 955 * pointer to the expiry value. 956 */ 957 if (end_time && !to) { 958 expire = timespec64_to_ktime(*end_time); 959 to = &expire; 960 } 961 962 if (!poll_schedule_timeout(wait, TASK_INTERRUPTIBLE, to, slack)) 963 timed_out = 1; 964 } 965 return count; 966 } 967 968 #define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list)) / \ 969 sizeof(struct pollfd)) 970 971 static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, 972 struct timespec64 *end_time) 973 { 974 struct poll_wqueues table; 975 int err = -EFAULT, fdcount, len; 976 /* Allocate small arguments on the stack to save memory and be 977 faster - use long to make sure the buffer is aligned properly 978 on 64 bit archs to avoid unaligned access */ 979 long stack_pps[POLL_STACK_ALLOC/sizeof(long)]; 980 struct poll_list *const head = (struct poll_list *)stack_pps; 981 struct poll_list *walk = head; 982 unsigned long todo = nfds; 983 984 if (nfds > rlimit(RLIMIT_NOFILE)) 985 return -EINVAL; 986 987 len = min_t(unsigned int, nfds, N_STACK_PPS); 988 for (;;) { 989 walk->next = NULL; 990 walk->len = len; 991 if (!len) 992 break; 993 994 if (copy_from_user(walk->entries, ufds + nfds-todo, 995 sizeof(struct pollfd) * walk->len)) 996 goto out_fds; 997 998 todo -= walk->len; 999 if (!todo) 1000 break; 1001 1002 len = min(todo, POLLFD_PER_PAGE); 1003 walk = walk->next = kmalloc(struct_size(walk, entries, len), 1004 GFP_KERNEL); 1005 if (!walk) { 1006 err = -ENOMEM; 1007 goto out_fds; 1008 } 1009 } 1010 1011 poll_initwait(&table); 1012 fdcount = do_poll(head, &table, end_time); 1013 poll_freewait(&table); 1014 1015 if (!user_write_access_begin(ufds, nfds * sizeof(*ufds))) 1016 goto out_fds; 1017 1018 for (walk = head; walk; walk = walk->next) { 1019 struct pollfd *fds = walk->entries; 1020 int j; 1021 1022 for (j = walk->len; j; fds++, ufds++, j--) 1023 unsafe_put_user(fds->revents, &ufds->revents, Efault); 1024 } 1025 user_write_access_end(); 1026 1027 err = fdcount; 1028 out_fds: 1029 walk = head->next; 1030 while (walk) { 1031 struct poll_list *pos = walk; 1032 walk = walk->next; 1033 kfree(pos); 1034 } 1035 1036 return err; 1037 1038 Efault: 1039 user_write_access_end(); 1040 err = -EFAULT; 1041 goto out_fds; 1042 } 1043 1044 static long do_restart_poll(struct restart_block *restart_block) 1045 { 1046 struct pollfd __user *ufds = restart_block->poll.ufds; 1047 int nfds = restart_block->poll.nfds; 1048 struct timespec64 *to = NULL, end_time; 1049 int ret; 1050 1051 if (restart_block->poll.has_timeout) { 1052 end_time.tv_sec = restart_block->poll.tv_sec; 1053 end_time.tv_nsec = restart_block->poll.tv_nsec; 1054 to = &end_time; 1055 } 1056 1057 ret = do_sys_poll(ufds, nfds, to); 1058 1059 if (ret == -ERESTARTNOHAND) 1060 ret = set_restart_fn(restart_block, do_restart_poll); 1061 1062 return ret; 1063 } 1064 1065 SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, 1066 int, timeout_msecs) 1067 { 1068 struct timespec64 end_time, *to = NULL; 1069 int ret; 1070 1071 if (timeout_msecs >= 0) { 1072 to = &end_time; 1073 poll_select_set_timeout(to, timeout_msecs / MSEC_PER_SEC, 1074 NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC)); 1075 } 1076 1077 ret = do_sys_poll(ufds, nfds, to); 1078 1079 if (ret == -ERESTARTNOHAND) { 1080 struct restart_block *restart_block; 1081 1082 restart_block = ¤t->restart_block; 1083 restart_block->poll.ufds = ufds; 1084 restart_block->poll.nfds = nfds; 1085 1086 if (timeout_msecs >= 0) { 1087 restart_block->poll.tv_sec = end_time.tv_sec; 1088 restart_block->poll.tv_nsec = end_time.tv_nsec; 1089 restart_block->poll.has_timeout = 1; 1090 } else 1091 restart_block->poll.has_timeout = 0; 1092 1093 ret = set_restart_fn(restart_block, do_restart_poll); 1094 } 1095 return ret; 1096 } 1097 1098 SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, 1099 struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask, 1100 size_t, sigsetsize) 1101 { 1102 struct timespec64 ts, end_time, *to = NULL; 1103 int ret; 1104 1105 if (tsp) { 1106 if (get_timespec64(&ts, tsp)) 1107 return -EFAULT; 1108 1109 to = &end_time; 1110 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1111 return -EINVAL; 1112 } 1113 1114 ret = set_user_sigmask(sigmask, sigsetsize); 1115 if (ret) 1116 return ret; 1117 1118 ret = do_sys_poll(ufds, nfds, to); 1119 return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); 1120 } 1121 1122 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) 1123 1124 SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, 1125 struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask, 1126 size_t, sigsetsize) 1127 { 1128 struct timespec64 ts, end_time, *to = NULL; 1129 int ret; 1130 1131 if (tsp) { 1132 if (get_old_timespec32(&ts, tsp)) 1133 return -EFAULT; 1134 1135 to = &end_time; 1136 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1137 return -EINVAL; 1138 } 1139 1140 ret = set_user_sigmask(sigmask, sigsetsize); 1141 if (ret) 1142 return ret; 1143 1144 ret = do_sys_poll(ufds, nfds, to); 1145 return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); 1146 } 1147 #endif 1148 1149 #ifdef CONFIG_COMPAT 1150 #define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t)) 1151 1152 /* 1153 * Ooo, nasty. We need here to frob 32-bit unsigned longs to 1154 * 64-bit unsigned longs. 1155 */ 1156 static 1157 int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, 1158 unsigned long *fdset) 1159 { 1160 if (ufdset) { 1161 return compat_get_bitmap(fdset, ufdset, nr); 1162 } else { 1163 zero_fd_set(nr, fdset); 1164 return 0; 1165 } 1166 } 1167 1168 static 1169 int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, 1170 unsigned long *fdset) 1171 { 1172 if (!ufdset) 1173 return 0; 1174 return compat_put_bitmap(ufdset, fdset, nr); 1175 } 1176 1177 1178 /* 1179 * This is a virtual copy of sys_select from fs/select.c and probably 1180 * should be compared to it from time to time 1181 */ 1182 1183 /* 1184 * We can actually return ERESTARTSYS instead of EINTR, but I'd 1185 * like to be certain this leads to no problems. So I return 1186 * EINTR just for safety. 1187 * 1188 * Update: ERESTARTSYS breaks at least the xview clock binary, so 1189 * I'm trying ERESTARTNOHAND which restart only when you want to. 1190 */ 1191 static int compat_core_sys_select(int n, compat_ulong_t __user *inp, 1192 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1193 struct timespec64 *end_time) 1194 { 1195 fd_set_bits fds; 1196 void *bits; 1197 int size, max_fds, ret = -EINVAL; 1198 struct fdtable *fdt; 1199 long stack_fds[SELECT_STACK_ALLOC/sizeof(long)]; 1200 1201 if (n < 0) 1202 goto out_nofds; 1203 1204 /* max_fds can increase, so grab it once to avoid race */ 1205 rcu_read_lock(); 1206 fdt = files_fdtable(current->files); 1207 max_fds = fdt->max_fds; 1208 rcu_read_unlock(); 1209 if (n > max_fds) 1210 n = max_fds; 1211 1212 /* 1213 * We need 6 bitmaps (in/out/ex for both incoming and outgoing), 1214 * since we used fdset we need to allocate memory in units of 1215 * long-words. 1216 */ 1217 size = FDS_BYTES(n); 1218 bits = stack_fds; 1219 if (size > sizeof(stack_fds) / 6) { 1220 bits = kmalloc_array(6, size, GFP_KERNEL); 1221 ret = -ENOMEM; 1222 if (!bits) 1223 goto out_nofds; 1224 } 1225 fds.in = (unsigned long *) bits; 1226 fds.out = (unsigned long *) (bits + size); 1227 fds.ex = (unsigned long *) (bits + 2*size); 1228 fds.res_in = (unsigned long *) (bits + 3*size); 1229 fds.res_out = (unsigned long *) (bits + 4*size); 1230 fds.res_ex = (unsigned long *) (bits + 5*size); 1231 1232 if ((ret = compat_get_fd_set(n, inp, fds.in)) || 1233 (ret = compat_get_fd_set(n, outp, fds.out)) || 1234 (ret = compat_get_fd_set(n, exp, fds.ex))) 1235 goto out; 1236 zero_fd_set(n, fds.res_in); 1237 zero_fd_set(n, fds.res_out); 1238 zero_fd_set(n, fds.res_ex); 1239 1240 ret = do_select(n, &fds, end_time); 1241 1242 if (ret < 0) 1243 goto out; 1244 if (!ret) { 1245 ret = -ERESTARTNOHAND; 1246 if (signal_pending(current)) 1247 goto out; 1248 ret = 0; 1249 } 1250 1251 if (compat_set_fd_set(n, inp, fds.res_in) || 1252 compat_set_fd_set(n, outp, fds.res_out) || 1253 compat_set_fd_set(n, exp, fds.res_ex)) 1254 ret = -EFAULT; 1255 out: 1256 if (bits != stack_fds) 1257 kfree(bits); 1258 out_nofds: 1259 return ret; 1260 } 1261 1262 static int do_compat_select(int n, compat_ulong_t __user *inp, 1263 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1264 struct old_timeval32 __user *tvp) 1265 { 1266 struct timespec64 end_time, *to = NULL; 1267 struct old_timeval32 tv; 1268 int ret; 1269 1270 if (tvp) { 1271 if (copy_from_user(&tv, tvp, sizeof(tv))) 1272 return -EFAULT; 1273 1274 to = &end_time; 1275 if (poll_select_set_timeout(to, 1276 tv.tv_sec + (tv.tv_usec / USEC_PER_SEC), 1277 (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC)) 1278 return -EINVAL; 1279 } 1280 1281 ret = compat_core_sys_select(n, inp, outp, exp, to); 1282 return poll_select_finish(&end_time, tvp, PT_OLD_TIMEVAL, ret); 1283 } 1284 1285 COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp, 1286 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1287 struct old_timeval32 __user *, tvp) 1288 { 1289 return do_compat_select(n, inp, outp, exp, tvp); 1290 } 1291 1292 struct compat_sel_arg_struct { 1293 compat_ulong_t n; 1294 compat_uptr_t inp; 1295 compat_uptr_t outp; 1296 compat_uptr_t exp; 1297 compat_uptr_t tvp; 1298 }; 1299 1300 COMPAT_SYSCALL_DEFINE1(old_select, struct compat_sel_arg_struct __user *, arg) 1301 { 1302 struct compat_sel_arg_struct a; 1303 1304 if (copy_from_user(&a, arg, sizeof(a))) 1305 return -EFAULT; 1306 return do_compat_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp), 1307 compat_ptr(a.exp), compat_ptr(a.tvp)); 1308 } 1309 1310 static long do_compat_pselect(int n, compat_ulong_t __user *inp, 1311 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1312 void __user *tsp, compat_sigset_t __user *sigmask, 1313 compat_size_t sigsetsize, enum poll_time_type type) 1314 { 1315 struct timespec64 ts, end_time, *to = NULL; 1316 int ret; 1317 1318 if (tsp) { 1319 switch (type) { 1320 case PT_OLD_TIMESPEC: 1321 if (get_old_timespec32(&ts, tsp)) 1322 return -EFAULT; 1323 break; 1324 case PT_TIMESPEC: 1325 if (get_timespec64(&ts, tsp)) 1326 return -EFAULT; 1327 break; 1328 default: 1329 BUG(); 1330 } 1331 1332 to = &end_time; 1333 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1334 return -EINVAL; 1335 } 1336 1337 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1338 if (ret) 1339 return ret; 1340 1341 ret = compat_core_sys_select(n, inp, outp, exp, to); 1342 return poll_select_finish(&end_time, tsp, type, ret); 1343 } 1344 1345 struct compat_sigset_argpack { 1346 compat_uptr_t p; 1347 compat_size_t size; 1348 }; 1349 static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to, 1350 struct compat_sigset_argpack __user *from) 1351 { 1352 if (from) { 1353 if (!user_read_access_begin(from, sizeof(*from))) 1354 return -EFAULT; 1355 unsafe_get_user(to->p, &from->p, Efault); 1356 unsafe_get_user(to->size, &from->size, Efault); 1357 user_read_access_end(); 1358 } 1359 return 0; 1360 Efault: 1361 user_access_end(); 1362 return -EFAULT; 1363 } 1364 1365 COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp, 1366 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1367 struct __kernel_timespec __user *, tsp, void __user *, sig) 1368 { 1369 struct compat_sigset_argpack x = {0, 0}; 1370 1371 if (get_compat_sigset_argpack(&x, sig)) 1372 return -EFAULT; 1373 1374 return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), 1375 x.size, PT_TIMESPEC); 1376 } 1377 1378 #if defined(CONFIG_COMPAT_32BIT_TIME) 1379 1380 COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp, 1381 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1382 struct old_timespec32 __user *, tsp, void __user *, sig) 1383 { 1384 struct compat_sigset_argpack x = {0, 0}; 1385 1386 if (get_compat_sigset_argpack(&x, sig)) 1387 return -EFAULT; 1388 1389 return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), 1390 x.size, PT_OLD_TIMESPEC); 1391 } 1392 1393 #endif 1394 1395 #if defined(CONFIG_COMPAT_32BIT_TIME) 1396 COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, 1397 unsigned int, nfds, struct old_timespec32 __user *, tsp, 1398 const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize) 1399 { 1400 struct timespec64 ts, end_time, *to = NULL; 1401 int ret; 1402 1403 if (tsp) { 1404 if (get_old_timespec32(&ts, tsp)) 1405 return -EFAULT; 1406 1407 to = &end_time; 1408 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1409 return -EINVAL; 1410 } 1411 1412 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1413 if (ret) 1414 return ret; 1415 1416 ret = do_sys_poll(ufds, nfds, to); 1417 return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); 1418 } 1419 #endif 1420 1421 /* New compat syscall for 64 bit time_t*/ 1422 COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds, 1423 unsigned int, nfds, struct __kernel_timespec __user *, tsp, 1424 const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize) 1425 { 1426 struct timespec64 ts, end_time, *to = NULL; 1427 int ret; 1428 1429 if (tsp) { 1430 if (get_timespec64(&ts, tsp)) 1431 return -EFAULT; 1432 1433 to = &end_time; 1434 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1435 return -EINVAL; 1436 } 1437 1438 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1439 if (ret) 1440 return ret; 1441 1442 ret = do_sys_poll(ufds, nfds, to); 1443 return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); 1444 } 1445 1446 #endif 1447