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 void wait_key_set(poll_table *wait, unsigned long in, 466 unsigned long out, unsigned long bit, 467 __poll_t ll_flag) 468 { 469 wait->_key = POLLEX_SET | ll_flag; 470 if (in & bit) 471 wait->_key |= POLLIN_SET; 472 if (out & bit) 473 wait->_key |= POLLOUT_SET; 474 } 475 476 static noinline_for_stack int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time) 477 { 478 ktime_t expire, *to = NULL; 479 struct poll_wqueues table; 480 poll_table *wait; 481 int retval, i, timed_out = 0; 482 u64 slack = 0; 483 __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; 484 unsigned long busy_start = 0; 485 486 rcu_read_lock(); 487 retval = max_select_fd(n, fds); 488 rcu_read_unlock(); 489 490 if (retval < 0) 491 return retval; 492 n = retval; 493 494 poll_initwait(&table); 495 wait = &table.pt; 496 if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { 497 wait->_qproc = NULL; 498 timed_out = 1; 499 } 500 501 if (end_time && !timed_out) 502 slack = select_estimate_accuracy(end_time); 503 504 retval = 0; 505 for (;;) { 506 unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp; 507 bool can_busy_loop = false; 508 509 inp = fds->in; outp = fds->out; exp = fds->ex; 510 rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex; 511 512 for (i = 0; i < n; ++rinp, ++routp, ++rexp) { 513 unsigned long in, out, ex, all_bits, bit = 1, j; 514 unsigned long res_in = 0, res_out = 0, res_ex = 0; 515 __poll_t mask; 516 517 in = *inp++; out = *outp++; ex = *exp++; 518 all_bits = in | out | ex; 519 if (all_bits == 0) { 520 i += BITS_PER_LONG; 521 continue; 522 } 523 524 for (j = 0; j < BITS_PER_LONG; ++j, ++i, bit <<= 1) { 525 struct fd f; 526 if (i >= n) 527 break; 528 if (!(bit & all_bits)) 529 continue; 530 mask = EPOLLNVAL; 531 f = fdget(i); 532 if (fd_file(f)) { 533 wait_key_set(wait, in, out, bit, 534 busy_flag); 535 mask = vfs_poll(fd_file(f), wait); 536 537 fdput(f); 538 } 539 if ((mask & POLLIN_SET) && (in & bit)) { 540 res_in |= bit; 541 retval++; 542 wait->_qproc = NULL; 543 } 544 if ((mask & POLLOUT_SET) && (out & bit)) { 545 res_out |= bit; 546 retval++; 547 wait->_qproc = NULL; 548 } 549 if ((mask & POLLEX_SET) && (ex & bit)) { 550 res_ex |= bit; 551 retval++; 552 wait->_qproc = NULL; 553 } 554 /* got something, stop busy polling */ 555 if (retval) { 556 can_busy_loop = false; 557 busy_flag = 0; 558 559 /* 560 * only remember a returned 561 * POLL_BUSY_LOOP if we asked for it 562 */ 563 } else if (busy_flag & mask) 564 can_busy_loop = true; 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 (can_do_masked_user_access()) 781 from = masked_user_access_begin(from); 782 else if (!user_read_access_begin(from, sizeof(*from))) 783 return -EFAULT; 784 unsafe_get_user(to->p, &from->p, Efault); 785 unsafe_get_user(to->size, &from->size, Efault); 786 user_read_access_end(); 787 } 788 return 0; 789 Efault: 790 user_access_end(); 791 return -EFAULT; 792 } 793 794 SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp, 795 fd_set __user *, exp, struct __kernel_timespec __user *, tsp, 796 void __user *, sig) 797 { 798 struct sigset_argpack x = {NULL, 0}; 799 800 if (get_sigset_argpack(&x, sig)) 801 return -EFAULT; 802 803 return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC); 804 } 805 806 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) 807 808 SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *, outp, 809 fd_set __user *, exp, struct old_timespec32 __user *, tsp, 810 void __user *, sig) 811 { 812 struct sigset_argpack x = {NULL, 0}; 813 814 if (get_sigset_argpack(&x, sig)) 815 return -EFAULT; 816 817 return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC); 818 } 819 820 #endif 821 822 #ifdef __ARCH_WANT_SYS_OLD_SELECT 823 struct sel_arg_struct { 824 unsigned long n; 825 fd_set __user *inp, *outp, *exp; 826 struct __kernel_old_timeval __user *tvp; 827 }; 828 829 SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg) 830 { 831 struct sel_arg_struct a; 832 833 if (copy_from_user(&a, arg, sizeof(a))) 834 return -EFAULT; 835 return kern_select(a.n, a.inp, a.outp, a.exp, a.tvp); 836 } 837 #endif 838 839 struct poll_list { 840 struct poll_list *next; 841 unsigned int len; 842 struct pollfd entries[] __counted_by(len); 843 }; 844 845 #define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd)) 846 847 /* 848 * Fish for pollable events on the pollfd->fd file descriptor. We're only 849 * interested in events matching the pollfd->events mask, and the result 850 * matching that mask is both recorded in pollfd->revents and returned. The 851 * pwait poll_table will be used by the fd-provided poll handler for waiting, 852 * if pwait->_qproc is non-NULL. 853 */ 854 static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait, 855 bool *can_busy_poll, 856 __poll_t busy_flag) 857 { 858 int fd = pollfd->fd; 859 __poll_t mask = 0, filter; 860 struct fd f; 861 862 if (fd < 0) 863 goto out; 864 mask = EPOLLNVAL; 865 f = fdget(fd); 866 if (!fd_file(f)) 867 goto out; 868 869 /* userland u16 ->events contains POLL... bitmap */ 870 filter = demangle_poll(pollfd->events) | EPOLLERR | EPOLLHUP; 871 pwait->_key = filter | busy_flag; 872 mask = vfs_poll(fd_file(f), pwait); 873 if (mask & busy_flag) 874 *can_busy_poll = true; 875 mask &= filter; /* Mask out unneeded events. */ 876 fdput(f); 877 878 out: 879 /* ... and so does ->revents */ 880 pollfd->revents = mangle_poll(mask); 881 return mask; 882 } 883 884 static int do_poll(struct poll_list *list, struct poll_wqueues *wait, 885 struct timespec64 *end_time) 886 { 887 poll_table* pt = &wait->pt; 888 ktime_t expire, *to = NULL; 889 int timed_out = 0, count = 0; 890 u64 slack = 0; 891 __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; 892 unsigned long busy_start = 0; 893 894 /* Optimise the no-wait case */ 895 if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { 896 pt->_qproc = NULL; 897 timed_out = 1; 898 } 899 900 if (end_time && !timed_out) 901 slack = select_estimate_accuracy(end_time); 902 903 for (;;) { 904 struct poll_list *walk; 905 bool can_busy_loop = false; 906 907 for (walk = list; walk != NULL; walk = walk->next) { 908 struct pollfd * pfd, * pfd_end; 909 910 pfd = walk->entries; 911 pfd_end = pfd + walk->len; 912 for (; pfd != pfd_end; pfd++) { 913 /* 914 * Fish for events. If we found one, record it 915 * and kill poll_table->_qproc, so we don't 916 * needlessly register any other waiters after 917 * this. They'll get immediately deregistered 918 * when we break out and return. 919 */ 920 if (do_pollfd(pfd, pt, &can_busy_loop, 921 busy_flag)) { 922 count++; 923 pt->_qproc = NULL; 924 /* found something, stop busy polling */ 925 busy_flag = 0; 926 can_busy_loop = false; 927 } 928 } 929 } 930 /* 931 * All waiters have already been registered, so don't provide 932 * a poll_table->_qproc to them on the next loop iteration. 933 */ 934 pt->_qproc = NULL; 935 if (!count) { 936 count = wait->error; 937 if (signal_pending(current)) 938 count = -ERESTARTNOHAND; 939 } 940 if (count || timed_out) 941 break; 942 943 /* only if found POLL_BUSY_LOOP sockets && not out of time */ 944 if (can_busy_loop && !need_resched()) { 945 if (!busy_start) { 946 busy_start = busy_loop_current_time(); 947 continue; 948 } 949 if (!busy_loop_timeout(busy_start)) 950 continue; 951 } 952 busy_flag = 0; 953 954 /* 955 * If this is the first loop and we have a timeout 956 * given, then we convert to ktime_t and set the to 957 * pointer to the expiry value. 958 */ 959 if (end_time && !to) { 960 expire = timespec64_to_ktime(*end_time); 961 to = &expire; 962 } 963 964 if (!poll_schedule_timeout(wait, TASK_INTERRUPTIBLE, to, slack)) 965 timed_out = 1; 966 } 967 return count; 968 } 969 970 #define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list)) / \ 971 sizeof(struct pollfd)) 972 973 static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, 974 struct timespec64 *end_time) 975 { 976 struct poll_wqueues table; 977 int err = -EFAULT, fdcount; 978 /* Allocate small arguments on the stack to save memory and be 979 faster - use long to make sure the buffer is aligned properly 980 on 64 bit archs to avoid unaligned access */ 981 long stack_pps[POLL_STACK_ALLOC/sizeof(long)]; 982 struct poll_list *const head = (struct poll_list *)stack_pps; 983 struct poll_list *walk = head; 984 unsigned int todo = nfds; 985 unsigned int len; 986 987 if (nfds > rlimit(RLIMIT_NOFILE)) 988 return -EINVAL; 989 990 len = min_t(unsigned int, nfds, N_STACK_PPS); 991 for (;;) { 992 walk->next = NULL; 993 walk->len = len; 994 if (!len) 995 break; 996 997 if (copy_from_user(walk->entries, ufds + nfds-todo, 998 sizeof(struct pollfd) * walk->len)) 999 goto out_fds; 1000 1001 if (walk->len >= todo) 1002 break; 1003 todo -= walk->len; 1004 1005 len = min(todo, POLLFD_PER_PAGE); 1006 walk = walk->next = kmalloc(struct_size(walk, entries, len), 1007 GFP_KERNEL); 1008 if (!walk) { 1009 err = -ENOMEM; 1010 goto out_fds; 1011 } 1012 } 1013 1014 poll_initwait(&table); 1015 fdcount = do_poll(head, &table, end_time); 1016 poll_freewait(&table); 1017 1018 if (!user_write_access_begin(ufds, nfds * sizeof(*ufds))) 1019 goto out_fds; 1020 1021 for (walk = head; walk; walk = walk->next) { 1022 struct pollfd *fds = walk->entries; 1023 unsigned int j; 1024 1025 for (j = walk->len; j; fds++, ufds++, j--) 1026 unsafe_put_user(fds->revents, &ufds->revents, Efault); 1027 } 1028 user_write_access_end(); 1029 1030 err = fdcount; 1031 out_fds: 1032 walk = head->next; 1033 while (walk) { 1034 struct poll_list *pos = walk; 1035 walk = walk->next; 1036 kfree(pos); 1037 } 1038 1039 return err; 1040 1041 Efault: 1042 user_write_access_end(); 1043 err = -EFAULT; 1044 goto out_fds; 1045 } 1046 1047 static long do_restart_poll(struct restart_block *restart_block) 1048 { 1049 struct pollfd __user *ufds = restart_block->poll.ufds; 1050 int nfds = restart_block->poll.nfds; 1051 struct timespec64 *to = NULL, end_time; 1052 int ret; 1053 1054 if (restart_block->poll.has_timeout) { 1055 end_time.tv_sec = restart_block->poll.tv_sec; 1056 end_time.tv_nsec = restart_block->poll.tv_nsec; 1057 to = &end_time; 1058 } 1059 1060 ret = do_sys_poll(ufds, nfds, to); 1061 1062 if (ret == -ERESTARTNOHAND) 1063 ret = set_restart_fn(restart_block, do_restart_poll); 1064 1065 return ret; 1066 } 1067 1068 SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, 1069 int, timeout_msecs) 1070 { 1071 struct timespec64 end_time, *to = NULL; 1072 int ret; 1073 1074 if (timeout_msecs >= 0) { 1075 to = &end_time; 1076 poll_select_set_timeout(to, timeout_msecs / MSEC_PER_SEC, 1077 NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC)); 1078 } 1079 1080 ret = do_sys_poll(ufds, nfds, to); 1081 1082 if (ret == -ERESTARTNOHAND) { 1083 struct restart_block *restart_block; 1084 1085 restart_block = ¤t->restart_block; 1086 restart_block->poll.ufds = ufds; 1087 restart_block->poll.nfds = nfds; 1088 1089 if (timeout_msecs >= 0) { 1090 restart_block->poll.tv_sec = end_time.tv_sec; 1091 restart_block->poll.tv_nsec = end_time.tv_nsec; 1092 restart_block->poll.has_timeout = 1; 1093 } else 1094 restart_block->poll.has_timeout = 0; 1095 1096 ret = set_restart_fn(restart_block, do_restart_poll); 1097 } 1098 return ret; 1099 } 1100 1101 SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, 1102 struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask, 1103 size_t, sigsetsize) 1104 { 1105 struct timespec64 ts, end_time, *to = NULL; 1106 int ret; 1107 1108 if (tsp) { 1109 if (get_timespec64(&ts, tsp)) 1110 return -EFAULT; 1111 1112 to = &end_time; 1113 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1114 return -EINVAL; 1115 } 1116 1117 ret = set_user_sigmask(sigmask, sigsetsize); 1118 if (ret) 1119 return ret; 1120 1121 ret = do_sys_poll(ufds, nfds, to); 1122 return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); 1123 } 1124 1125 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) 1126 1127 SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, 1128 struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask, 1129 size_t, sigsetsize) 1130 { 1131 struct timespec64 ts, end_time, *to = NULL; 1132 int ret; 1133 1134 if (tsp) { 1135 if (get_old_timespec32(&ts, tsp)) 1136 return -EFAULT; 1137 1138 to = &end_time; 1139 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1140 return -EINVAL; 1141 } 1142 1143 ret = set_user_sigmask(sigmask, sigsetsize); 1144 if (ret) 1145 return ret; 1146 1147 ret = do_sys_poll(ufds, nfds, to); 1148 return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); 1149 } 1150 #endif 1151 1152 #ifdef CONFIG_COMPAT 1153 #define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t)) 1154 1155 /* 1156 * Ooo, nasty. We need here to frob 32-bit unsigned longs to 1157 * 64-bit unsigned longs. 1158 */ 1159 static 1160 int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, 1161 unsigned long *fdset) 1162 { 1163 if (ufdset) { 1164 return compat_get_bitmap(fdset, ufdset, nr); 1165 } else { 1166 zero_fd_set(nr, fdset); 1167 return 0; 1168 } 1169 } 1170 1171 static 1172 int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, 1173 unsigned long *fdset) 1174 { 1175 if (!ufdset) 1176 return 0; 1177 return compat_put_bitmap(ufdset, fdset, nr); 1178 } 1179 1180 1181 /* 1182 * This is a virtual copy of sys_select from fs/select.c and probably 1183 * should be compared to it from time to time 1184 */ 1185 1186 /* 1187 * We can actually return ERESTARTSYS instead of EINTR, but I'd 1188 * like to be certain this leads to no problems. So I return 1189 * EINTR just for safety. 1190 * 1191 * Update: ERESTARTSYS breaks at least the xview clock binary, so 1192 * I'm trying ERESTARTNOHAND which restart only when you want to. 1193 */ 1194 static int compat_core_sys_select(int n, compat_ulong_t __user *inp, 1195 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1196 struct timespec64 *end_time) 1197 { 1198 fd_set_bits fds; 1199 void *bits; 1200 int size, max_fds, ret = -EINVAL; 1201 struct fdtable *fdt; 1202 long stack_fds[SELECT_STACK_ALLOC/sizeof(long)]; 1203 1204 if (n < 0) 1205 goto out_nofds; 1206 1207 /* max_fds can increase, so grab it once to avoid race */ 1208 rcu_read_lock(); 1209 fdt = files_fdtable(current->files); 1210 max_fds = fdt->max_fds; 1211 rcu_read_unlock(); 1212 if (n > max_fds) 1213 n = max_fds; 1214 1215 /* 1216 * We need 6 bitmaps (in/out/ex for both incoming and outgoing), 1217 * since we used fdset we need to allocate memory in units of 1218 * long-words. 1219 */ 1220 size = FDS_BYTES(n); 1221 bits = stack_fds; 1222 if (size > sizeof(stack_fds) / 6) { 1223 bits = kmalloc_array(6, size, GFP_KERNEL); 1224 ret = -ENOMEM; 1225 if (!bits) 1226 goto out_nofds; 1227 } 1228 fds.in = (unsigned long *) bits; 1229 fds.out = (unsigned long *) (bits + size); 1230 fds.ex = (unsigned long *) (bits + 2*size); 1231 fds.res_in = (unsigned long *) (bits + 3*size); 1232 fds.res_out = (unsigned long *) (bits + 4*size); 1233 fds.res_ex = (unsigned long *) (bits + 5*size); 1234 1235 if ((ret = compat_get_fd_set(n, inp, fds.in)) || 1236 (ret = compat_get_fd_set(n, outp, fds.out)) || 1237 (ret = compat_get_fd_set(n, exp, fds.ex))) 1238 goto out; 1239 zero_fd_set(n, fds.res_in); 1240 zero_fd_set(n, fds.res_out); 1241 zero_fd_set(n, fds.res_ex); 1242 1243 ret = do_select(n, &fds, end_time); 1244 1245 if (ret < 0) 1246 goto out; 1247 if (!ret) { 1248 ret = -ERESTARTNOHAND; 1249 if (signal_pending(current)) 1250 goto out; 1251 ret = 0; 1252 } 1253 1254 if (compat_set_fd_set(n, inp, fds.res_in) || 1255 compat_set_fd_set(n, outp, fds.res_out) || 1256 compat_set_fd_set(n, exp, fds.res_ex)) 1257 ret = -EFAULT; 1258 out: 1259 if (bits != stack_fds) 1260 kfree(bits); 1261 out_nofds: 1262 return ret; 1263 } 1264 1265 static int do_compat_select(int n, compat_ulong_t __user *inp, 1266 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1267 struct old_timeval32 __user *tvp) 1268 { 1269 struct timespec64 end_time, *to = NULL; 1270 struct old_timeval32 tv; 1271 int ret; 1272 1273 if (tvp) { 1274 if (copy_from_user(&tv, tvp, sizeof(tv))) 1275 return -EFAULT; 1276 1277 to = &end_time; 1278 if (poll_select_set_timeout(to, 1279 tv.tv_sec + (tv.tv_usec / USEC_PER_SEC), 1280 (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC)) 1281 return -EINVAL; 1282 } 1283 1284 ret = compat_core_sys_select(n, inp, outp, exp, to); 1285 return poll_select_finish(&end_time, tvp, PT_OLD_TIMEVAL, ret); 1286 } 1287 1288 COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp, 1289 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1290 struct old_timeval32 __user *, tvp) 1291 { 1292 return do_compat_select(n, inp, outp, exp, tvp); 1293 } 1294 1295 struct compat_sel_arg_struct { 1296 compat_ulong_t n; 1297 compat_uptr_t inp; 1298 compat_uptr_t outp; 1299 compat_uptr_t exp; 1300 compat_uptr_t tvp; 1301 }; 1302 1303 COMPAT_SYSCALL_DEFINE1(old_select, struct compat_sel_arg_struct __user *, arg) 1304 { 1305 struct compat_sel_arg_struct a; 1306 1307 if (copy_from_user(&a, arg, sizeof(a))) 1308 return -EFAULT; 1309 return do_compat_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp), 1310 compat_ptr(a.exp), compat_ptr(a.tvp)); 1311 } 1312 1313 static long do_compat_pselect(int n, compat_ulong_t __user *inp, 1314 compat_ulong_t __user *outp, compat_ulong_t __user *exp, 1315 void __user *tsp, compat_sigset_t __user *sigmask, 1316 compat_size_t sigsetsize, enum poll_time_type type) 1317 { 1318 struct timespec64 ts, end_time, *to = NULL; 1319 int ret; 1320 1321 if (tsp) { 1322 switch (type) { 1323 case PT_OLD_TIMESPEC: 1324 if (get_old_timespec32(&ts, tsp)) 1325 return -EFAULT; 1326 break; 1327 case PT_TIMESPEC: 1328 if (get_timespec64(&ts, tsp)) 1329 return -EFAULT; 1330 break; 1331 default: 1332 BUG(); 1333 } 1334 1335 to = &end_time; 1336 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1337 return -EINVAL; 1338 } 1339 1340 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1341 if (ret) 1342 return ret; 1343 1344 ret = compat_core_sys_select(n, inp, outp, exp, to); 1345 return poll_select_finish(&end_time, tsp, type, ret); 1346 } 1347 1348 struct compat_sigset_argpack { 1349 compat_uptr_t p; 1350 compat_size_t size; 1351 }; 1352 static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to, 1353 struct compat_sigset_argpack __user *from) 1354 { 1355 if (from) { 1356 if (!user_read_access_begin(from, sizeof(*from))) 1357 return -EFAULT; 1358 unsafe_get_user(to->p, &from->p, Efault); 1359 unsafe_get_user(to->size, &from->size, Efault); 1360 user_read_access_end(); 1361 } 1362 return 0; 1363 Efault: 1364 user_access_end(); 1365 return -EFAULT; 1366 } 1367 1368 COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp, 1369 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1370 struct __kernel_timespec __user *, tsp, void __user *, sig) 1371 { 1372 struct compat_sigset_argpack x = {0, 0}; 1373 1374 if (get_compat_sigset_argpack(&x, sig)) 1375 return -EFAULT; 1376 1377 return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), 1378 x.size, PT_TIMESPEC); 1379 } 1380 1381 #if defined(CONFIG_COMPAT_32BIT_TIME) 1382 1383 COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp, 1384 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, 1385 struct old_timespec32 __user *, tsp, void __user *, sig) 1386 { 1387 struct compat_sigset_argpack x = {0, 0}; 1388 1389 if (get_compat_sigset_argpack(&x, sig)) 1390 return -EFAULT; 1391 1392 return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), 1393 x.size, PT_OLD_TIMESPEC); 1394 } 1395 1396 #endif 1397 1398 #if defined(CONFIG_COMPAT_32BIT_TIME) 1399 COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, 1400 unsigned int, nfds, struct old_timespec32 __user *, tsp, 1401 const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize) 1402 { 1403 struct timespec64 ts, end_time, *to = NULL; 1404 int ret; 1405 1406 if (tsp) { 1407 if (get_old_timespec32(&ts, tsp)) 1408 return -EFAULT; 1409 1410 to = &end_time; 1411 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1412 return -EINVAL; 1413 } 1414 1415 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1416 if (ret) 1417 return ret; 1418 1419 ret = do_sys_poll(ufds, nfds, to); 1420 return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); 1421 } 1422 #endif 1423 1424 /* New compat syscall for 64 bit time_t*/ 1425 COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds, 1426 unsigned int, nfds, struct __kernel_timespec __user *, tsp, 1427 const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize) 1428 { 1429 struct timespec64 ts, end_time, *to = NULL; 1430 int ret; 1431 1432 if (tsp) { 1433 if (get_timespec64(&ts, tsp)) 1434 return -EFAULT; 1435 1436 to = &end_time; 1437 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) 1438 return -EINVAL; 1439 } 1440 1441 ret = set_compat_user_sigmask(sigmask, sigsetsize); 1442 if (ret) 1443 return ret; 1444 1445 ret = do_sys_poll(ufds, nfds, to); 1446 return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); 1447 } 1448 1449 #endif 1450