sys_generic.c revision 257122
1/*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: stable/10/sys/kern/sys_generic.c 257122 2013-10-25 16:33:24Z kib $"); 39 40#include "opt_capsicum.h" 41#include "opt_compat.h" 42#include "opt_ktrace.h" 43 44#include <sys/param.h> 45#include <sys/systm.h> 46#include <sys/sysproto.h> 47#include <sys/capability.h> 48#include <sys/filedesc.h> 49#include <sys/filio.h> 50#include <sys/fcntl.h> 51#include <sys/file.h> 52#include <sys/lock.h> 53#include <sys/proc.h> 54#include <sys/signalvar.h> 55#include <sys/socketvar.h> 56#include <sys/uio.h> 57#include <sys/kernel.h> 58#include <sys/ktr.h> 59#include <sys/limits.h> 60#include <sys/malloc.h> 61#include <sys/poll.h> 62#include <sys/resourcevar.h> 63#include <sys/selinfo.h> 64#include <sys/sleepqueue.h> 65#include <sys/syscallsubr.h> 66#include <sys/sysctl.h> 67#include <sys/sysent.h> 68#include <sys/vnode.h> 69#include <sys/bio.h> 70#include <sys/buf.h> 71#include <sys/condvar.h> 72#ifdef KTRACE 73#include <sys/ktrace.h> 74#endif 75 76#include <security/audit/audit.h> 77 78int iosize_max_clamp = 1; 79SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, 80 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); 81int devfs_iosize_max_clamp = 1; 82SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW, 83 &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices"); 84 85/* 86 * Assert that the return value of read(2) and write(2) syscalls fits 87 * into a register. If not, an architecture will need to provide the 88 * usermode wrappers to reconstruct the result. 89 */ 90CTASSERT(sizeof(register_t) >= sizeof(size_t)); 91 92static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 93static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); 94MALLOC_DEFINE(M_IOV, "iov", "large iov's"); 95 96static int pollout(struct thread *, struct pollfd *, struct pollfd *, 97 u_int); 98static int pollscan(struct thread *, struct pollfd *, u_int); 99static int pollrescan(struct thread *); 100static int selscan(struct thread *, fd_mask **, fd_mask **, int); 101static int selrescan(struct thread *, fd_mask **, fd_mask **); 102static void selfdalloc(struct thread *, void *); 103static void selfdfree(struct seltd *, struct selfd *); 104static int dofileread(struct thread *, int, struct file *, struct uio *, 105 off_t, int); 106static int dofilewrite(struct thread *, int, struct file *, struct uio *, 107 off_t, int); 108static void doselwakeup(struct selinfo *, int); 109static void seltdinit(struct thread *); 110static int seltdwait(struct thread *, sbintime_t, sbintime_t); 111static void seltdclear(struct thread *); 112 113/* 114 * One seltd per-thread allocated on demand as needed. 115 * 116 * t - protected by st_mtx 117 * k - Only accessed by curthread or read-only 118 */ 119struct seltd { 120 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ 121 struct selfd *st_free1; /* (k) free fd for read set. */ 122 struct selfd *st_free2; /* (k) free fd for write set. */ 123 struct mtx st_mtx; /* Protects struct seltd */ 124 struct cv st_wait; /* (t) Wait channel. */ 125 int st_flags; /* (t) SELTD_ flags. */ 126}; 127 128#define SELTD_PENDING 0x0001 /* We have pending events. */ 129#define SELTD_RESCAN 0x0002 /* Doing a rescan. */ 130 131/* 132 * One selfd allocated per-thread per-file-descriptor. 133 * f - protected by sf_mtx 134 */ 135struct selfd { 136 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ 137 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ 138 struct selinfo *sf_si; /* (f) selinfo when linked. */ 139 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ 140 struct seltd *sf_td; /* (k) owning seltd. */ 141 void *sf_cookie; /* (k) fd or pollfd. */ 142}; 143 144static uma_zone_t selfd_zone; 145static struct mtx_pool *mtxpool_select; 146 147#ifndef _SYS_SYSPROTO_H_ 148struct read_args { 149 int fd; 150 void *buf; 151 size_t nbyte; 152}; 153#endif 154int 155sys_read(td, uap) 156 struct thread *td; 157 struct read_args *uap; 158{ 159 struct uio auio; 160 struct iovec aiov; 161 int error; 162 163 if (uap->nbyte > IOSIZE_MAX) 164 return (EINVAL); 165 aiov.iov_base = uap->buf; 166 aiov.iov_len = uap->nbyte; 167 auio.uio_iov = &aiov; 168 auio.uio_iovcnt = 1; 169 auio.uio_resid = uap->nbyte; 170 auio.uio_segflg = UIO_USERSPACE; 171 error = kern_readv(td, uap->fd, &auio); 172 return(error); 173} 174 175/* 176 * Positioned read system call 177 */ 178#ifndef _SYS_SYSPROTO_H_ 179struct pread_args { 180 int fd; 181 void *buf; 182 size_t nbyte; 183 int pad; 184 off_t offset; 185}; 186#endif 187int 188sys_pread(td, uap) 189 struct thread *td; 190 struct pread_args *uap; 191{ 192 struct uio auio; 193 struct iovec aiov; 194 int error; 195 196 if (uap->nbyte > IOSIZE_MAX) 197 return (EINVAL); 198 aiov.iov_base = uap->buf; 199 aiov.iov_len = uap->nbyte; 200 auio.uio_iov = &aiov; 201 auio.uio_iovcnt = 1; 202 auio.uio_resid = uap->nbyte; 203 auio.uio_segflg = UIO_USERSPACE; 204 error = kern_preadv(td, uap->fd, &auio, uap->offset); 205 return(error); 206} 207 208int 209freebsd6_pread(td, uap) 210 struct thread *td; 211 struct freebsd6_pread_args *uap; 212{ 213 struct pread_args oargs; 214 215 oargs.fd = uap->fd; 216 oargs.buf = uap->buf; 217 oargs.nbyte = uap->nbyte; 218 oargs.offset = uap->offset; 219 return (sys_pread(td, &oargs)); 220} 221 222/* 223 * Scatter read system call. 224 */ 225#ifndef _SYS_SYSPROTO_H_ 226struct readv_args { 227 int fd; 228 struct iovec *iovp; 229 u_int iovcnt; 230}; 231#endif 232int 233sys_readv(struct thread *td, struct readv_args *uap) 234{ 235 struct uio *auio; 236 int error; 237 238 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 239 if (error) 240 return (error); 241 error = kern_readv(td, uap->fd, auio); 242 free(auio, M_IOV); 243 return (error); 244} 245 246int 247kern_readv(struct thread *td, int fd, struct uio *auio) 248{ 249 struct file *fp; 250 cap_rights_t rights; 251 int error; 252 253 error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp); 254 if (error) 255 return (error); 256 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 257 fdrop(fp, td); 258 return (error); 259} 260 261/* 262 * Scatter positioned read system call. 263 */ 264#ifndef _SYS_SYSPROTO_H_ 265struct preadv_args { 266 int fd; 267 struct iovec *iovp; 268 u_int iovcnt; 269 off_t offset; 270}; 271#endif 272int 273sys_preadv(struct thread *td, struct preadv_args *uap) 274{ 275 struct uio *auio; 276 int error; 277 278 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 279 if (error) 280 return (error); 281 error = kern_preadv(td, uap->fd, auio, uap->offset); 282 free(auio, M_IOV); 283 return (error); 284} 285 286int 287kern_preadv(td, fd, auio, offset) 288 struct thread *td; 289 int fd; 290 struct uio *auio; 291 off_t offset; 292{ 293 struct file *fp; 294 cap_rights_t rights; 295 int error; 296 297 error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp); 298 if (error) 299 return (error); 300 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 301 error = ESPIPE; 302 else if (offset < 0 && fp->f_vnode->v_type != VCHR) 303 error = EINVAL; 304 else 305 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 306 fdrop(fp, td); 307 return (error); 308} 309 310/* 311 * Common code for readv and preadv that reads data in 312 * from a file using the passed in uio, offset, and flags. 313 */ 314static int 315dofileread(td, fd, fp, auio, offset, flags) 316 struct thread *td; 317 int fd; 318 struct file *fp; 319 struct uio *auio; 320 off_t offset; 321 int flags; 322{ 323 ssize_t cnt; 324 int error; 325#ifdef KTRACE 326 struct uio *ktruio = NULL; 327#endif 328 329 /* Finish zero length reads right here */ 330 if (auio->uio_resid == 0) { 331 td->td_retval[0] = 0; 332 return(0); 333 } 334 auio->uio_rw = UIO_READ; 335 auio->uio_offset = offset; 336 auio->uio_td = td; 337#ifdef KTRACE 338 if (KTRPOINT(td, KTR_GENIO)) 339 ktruio = cloneuio(auio); 340#endif 341 cnt = auio->uio_resid; 342 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 343 if (auio->uio_resid != cnt && (error == ERESTART || 344 error == EINTR || error == EWOULDBLOCK)) 345 error = 0; 346 } 347 cnt -= auio->uio_resid; 348#ifdef KTRACE 349 if (ktruio != NULL) { 350 ktruio->uio_resid = cnt; 351 ktrgenio(fd, UIO_READ, ktruio, error); 352 } 353#endif 354 td->td_retval[0] = cnt; 355 return (error); 356} 357 358#ifndef _SYS_SYSPROTO_H_ 359struct write_args { 360 int fd; 361 const void *buf; 362 size_t nbyte; 363}; 364#endif 365int 366sys_write(td, uap) 367 struct thread *td; 368 struct write_args *uap; 369{ 370 struct uio auio; 371 struct iovec aiov; 372 int error; 373 374 if (uap->nbyte > IOSIZE_MAX) 375 return (EINVAL); 376 aiov.iov_base = (void *)(uintptr_t)uap->buf; 377 aiov.iov_len = uap->nbyte; 378 auio.uio_iov = &aiov; 379 auio.uio_iovcnt = 1; 380 auio.uio_resid = uap->nbyte; 381 auio.uio_segflg = UIO_USERSPACE; 382 error = kern_writev(td, uap->fd, &auio); 383 return(error); 384} 385 386/* 387 * Positioned write system call. 388 */ 389#ifndef _SYS_SYSPROTO_H_ 390struct pwrite_args { 391 int fd; 392 const void *buf; 393 size_t nbyte; 394 int pad; 395 off_t offset; 396}; 397#endif 398int 399sys_pwrite(td, uap) 400 struct thread *td; 401 struct pwrite_args *uap; 402{ 403 struct uio auio; 404 struct iovec aiov; 405 int error; 406 407 if (uap->nbyte > IOSIZE_MAX) 408 return (EINVAL); 409 aiov.iov_base = (void *)(uintptr_t)uap->buf; 410 aiov.iov_len = uap->nbyte; 411 auio.uio_iov = &aiov; 412 auio.uio_iovcnt = 1; 413 auio.uio_resid = uap->nbyte; 414 auio.uio_segflg = UIO_USERSPACE; 415 error = kern_pwritev(td, uap->fd, &auio, uap->offset); 416 return(error); 417} 418 419int 420freebsd6_pwrite(td, uap) 421 struct thread *td; 422 struct freebsd6_pwrite_args *uap; 423{ 424 struct pwrite_args oargs; 425 426 oargs.fd = uap->fd; 427 oargs.buf = uap->buf; 428 oargs.nbyte = uap->nbyte; 429 oargs.offset = uap->offset; 430 return (sys_pwrite(td, &oargs)); 431} 432 433/* 434 * Gather write system call. 435 */ 436#ifndef _SYS_SYSPROTO_H_ 437struct writev_args { 438 int fd; 439 struct iovec *iovp; 440 u_int iovcnt; 441}; 442#endif 443int 444sys_writev(struct thread *td, struct writev_args *uap) 445{ 446 struct uio *auio; 447 int error; 448 449 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 450 if (error) 451 return (error); 452 error = kern_writev(td, uap->fd, auio); 453 free(auio, M_IOV); 454 return (error); 455} 456 457int 458kern_writev(struct thread *td, int fd, struct uio *auio) 459{ 460 struct file *fp; 461 cap_rights_t rights; 462 int error; 463 464 error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp); 465 if (error) 466 return (error); 467 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 468 fdrop(fp, td); 469 return (error); 470} 471 472/* 473 * Gather positioned write system call. 474 */ 475#ifndef _SYS_SYSPROTO_H_ 476struct pwritev_args { 477 int fd; 478 struct iovec *iovp; 479 u_int iovcnt; 480 off_t offset; 481}; 482#endif 483int 484sys_pwritev(struct thread *td, struct pwritev_args *uap) 485{ 486 struct uio *auio; 487 int error; 488 489 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 490 if (error) 491 return (error); 492 error = kern_pwritev(td, uap->fd, auio, uap->offset); 493 free(auio, M_IOV); 494 return (error); 495} 496 497int 498kern_pwritev(td, fd, auio, offset) 499 struct thread *td; 500 struct uio *auio; 501 int fd; 502 off_t offset; 503{ 504 struct file *fp; 505 cap_rights_t rights; 506 int error; 507 508 error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp); 509 if (error) 510 return (error); 511 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 512 error = ESPIPE; 513 else if (offset < 0 && fp->f_vnode->v_type != VCHR) 514 error = EINVAL; 515 else 516 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 517 fdrop(fp, td); 518 return (error); 519} 520 521/* 522 * Common code for writev and pwritev that writes data to 523 * a file using the passed in uio, offset, and flags. 524 */ 525static int 526dofilewrite(td, fd, fp, auio, offset, flags) 527 struct thread *td; 528 int fd; 529 struct file *fp; 530 struct uio *auio; 531 off_t offset; 532 int flags; 533{ 534 ssize_t cnt; 535 int error; 536#ifdef KTRACE 537 struct uio *ktruio = NULL; 538#endif 539 540 auio->uio_rw = UIO_WRITE; 541 auio->uio_td = td; 542 auio->uio_offset = offset; 543#ifdef KTRACE 544 if (KTRPOINT(td, KTR_GENIO)) 545 ktruio = cloneuio(auio); 546#endif 547 cnt = auio->uio_resid; 548 if (fp->f_type == DTYPE_VNODE && 549 (fp->f_vnread_flags & FDEVFS_VNODE) == 0) 550 bwillwrite(); 551 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 552 if (auio->uio_resid != cnt && (error == ERESTART || 553 error == EINTR || error == EWOULDBLOCK)) 554 error = 0; 555 /* Socket layer is responsible for issuing SIGPIPE. */ 556 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 557 PROC_LOCK(td->td_proc); 558 tdsignal(td, SIGPIPE); 559 PROC_UNLOCK(td->td_proc); 560 } 561 } 562 cnt -= auio->uio_resid; 563#ifdef KTRACE 564 if (ktruio != NULL) { 565 ktruio->uio_resid = cnt; 566 ktrgenio(fd, UIO_WRITE, ktruio, error); 567 } 568#endif 569 td->td_retval[0] = cnt; 570 return (error); 571} 572 573/* 574 * Truncate a file given a file descriptor. 575 * 576 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 577 * descriptor isn't writable. 578 */ 579int 580kern_ftruncate(td, fd, length) 581 struct thread *td; 582 int fd; 583 off_t length; 584{ 585 struct file *fp; 586 cap_rights_t rights; 587 int error; 588 589 AUDIT_ARG_FD(fd); 590 if (length < 0) 591 return (EINVAL); 592 error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp); 593 if (error) 594 return (error); 595 AUDIT_ARG_FILE(td->td_proc, fp); 596 if (!(fp->f_flag & FWRITE)) { 597 fdrop(fp, td); 598 return (EINVAL); 599 } 600 error = fo_truncate(fp, length, td->td_ucred, td); 601 fdrop(fp, td); 602 return (error); 603} 604 605#ifndef _SYS_SYSPROTO_H_ 606struct ftruncate_args { 607 int fd; 608 int pad; 609 off_t length; 610}; 611#endif 612int 613sys_ftruncate(td, uap) 614 struct thread *td; 615 struct ftruncate_args *uap; 616{ 617 618 return (kern_ftruncate(td, uap->fd, uap->length)); 619} 620 621#if defined(COMPAT_43) 622#ifndef _SYS_SYSPROTO_H_ 623struct oftruncate_args { 624 int fd; 625 long length; 626}; 627#endif 628int 629oftruncate(td, uap) 630 struct thread *td; 631 struct oftruncate_args *uap; 632{ 633 634 return (kern_ftruncate(td, uap->fd, uap->length)); 635} 636#endif /* COMPAT_43 */ 637 638#ifndef _SYS_SYSPROTO_H_ 639struct ioctl_args { 640 int fd; 641 u_long com; 642 caddr_t data; 643}; 644#endif 645/* ARGSUSED */ 646int 647sys_ioctl(struct thread *td, struct ioctl_args *uap) 648{ 649 u_long com; 650 int arg, error; 651 u_int size; 652 caddr_t data; 653 654 if (uap->com > 0xffffffff) { 655 printf( 656 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 657 td->td_proc->p_pid, td->td_name, uap->com); 658 uap->com &= 0xffffffff; 659 } 660 com = uap->com; 661 662 /* 663 * Interpret high order word to find amount of data to be 664 * copied to/from the user's address space. 665 */ 666 size = IOCPARM_LEN(com); 667 if ((size > IOCPARM_MAX) || 668 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 669#if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 670 ((com & IOC_OUT) && size == 0) || 671#else 672 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 673#endif 674 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 675 return (ENOTTY); 676 677 if (size > 0) { 678 if (com & IOC_VOID) { 679 /* Integer argument. */ 680 arg = (intptr_t)uap->data; 681 data = (void *)&arg; 682 size = 0; 683 } else 684 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 685 } else 686 data = (void *)&uap->data; 687 if (com & IOC_IN) { 688 error = copyin(uap->data, data, (u_int)size); 689 if (error) { 690 if (size > 0) 691 free(data, M_IOCTLOPS); 692 return (error); 693 } 694 } else if (com & IOC_OUT) { 695 /* 696 * Zero the buffer so the user always 697 * gets back something deterministic. 698 */ 699 bzero(data, size); 700 } 701 702 error = kern_ioctl(td, uap->fd, com, data); 703 704 if (error == 0 && (com & IOC_OUT)) 705 error = copyout(data, uap->data, (u_int)size); 706 707 if (size > 0) 708 free(data, M_IOCTLOPS); 709 return (error); 710} 711 712int 713kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 714{ 715 struct file *fp; 716 struct filedesc *fdp; 717#ifndef CAPABILITIES 718 cap_rights_t rights; 719#endif 720 int error, tmp, locked; 721 722 AUDIT_ARG_FD(fd); 723 AUDIT_ARG_CMD(com); 724 725 fdp = td->td_proc->p_fd; 726 727 switch (com) { 728 case FIONCLEX: 729 case FIOCLEX: 730 FILEDESC_XLOCK(fdp); 731 locked = LA_XLOCKED; 732 break; 733 default: 734#ifdef CAPABILITIES 735 FILEDESC_SLOCK(fdp); 736 locked = LA_SLOCKED; 737#else 738 locked = LA_UNLOCKED; 739#endif 740 break; 741 } 742 743#ifdef CAPABILITIES 744 if ((fp = fget_locked(fdp, fd)) == NULL) { 745 error = EBADF; 746 goto out; 747 } 748 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 749 fp = NULL; /* fhold() was not called yet */ 750 goto out; 751 } 752 fhold(fp); 753 if (locked == LA_SLOCKED) { 754 FILEDESC_SUNLOCK(fdp); 755 locked = LA_UNLOCKED; 756 } 757#else 758 error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp); 759 if (error != 0) { 760 fp = NULL; 761 goto out; 762 } 763#endif 764 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 765 error = EBADF; 766 goto out; 767 } 768 769 switch (com) { 770 case FIONCLEX: 771 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 772 goto out; 773 case FIOCLEX: 774 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 775 goto out; 776 case FIONBIO: 777 if ((tmp = *(int *)data)) 778 atomic_set_int(&fp->f_flag, FNONBLOCK); 779 else 780 atomic_clear_int(&fp->f_flag, FNONBLOCK); 781 data = (void *)&tmp; 782 break; 783 case FIOASYNC: 784 if ((tmp = *(int *)data)) 785 atomic_set_int(&fp->f_flag, FASYNC); 786 else 787 atomic_clear_int(&fp->f_flag, FASYNC); 788 data = (void *)&tmp; 789 break; 790 } 791 792 error = fo_ioctl(fp, com, data, td->td_ucred, td); 793out: 794 switch (locked) { 795 case LA_XLOCKED: 796 FILEDESC_XUNLOCK(fdp); 797 break; 798#ifdef CAPABILITIES 799 case LA_SLOCKED: 800 FILEDESC_SUNLOCK(fdp); 801 break; 802#endif 803 default: 804 FILEDESC_UNLOCK_ASSERT(fdp); 805 break; 806 } 807 if (fp != NULL) 808 fdrop(fp, td); 809 return (error); 810} 811 812int 813poll_no_poll(int events) 814{ 815 /* 816 * Return true for read/write. If the user asked for something 817 * special, return POLLNVAL, so that clients have a way of 818 * determining reliably whether or not the extended 819 * functionality is present without hard-coding knowledge 820 * of specific filesystem implementations. 821 */ 822 if (events & ~POLLSTANDARD) 823 return (POLLNVAL); 824 825 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 826} 827 828int 829sys_pselect(struct thread *td, struct pselect_args *uap) 830{ 831 struct timespec ts; 832 struct timeval tv, *tvp; 833 sigset_t set, *uset; 834 int error; 835 836 if (uap->ts != NULL) { 837 error = copyin(uap->ts, &ts, sizeof(ts)); 838 if (error != 0) 839 return (error); 840 TIMESPEC_TO_TIMEVAL(&tv, &ts); 841 tvp = &tv; 842 } else 843 tvp = NULL; 844 if (uap->sm != NULL) { 845 error = copyin(uap->sm, &set, sizeof(set)); 846 if (error != 0) 847 return (error); 848 uset = &set; 849 } else 850 uset = NULL; 851 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 852 uset, NFDBITS)); 853} 854 855int 856kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 857 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 858{ 859 int error; 860 861 if (uset != NULL) { 862 error = kern_sigprocmask(td, SIG_SETMASK, uset, 863 &td->td_oldsigmask, 0); 864 if (error != 0) 865 return (error); 866 td->td_pflags |= TDP_OLDMASK; 867 /* 868 * Make sure that ast() is called on return to 869 * usermode and TDP_OLDMASK is cleared, restoring old 870 * sigmask. 871 */ 872 thread_lock(td); 873 td->td_flags |= TDF_ASTPENDING; 874 thread_unlock(td); 875 } 876 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 877 return (error); 878} 879 880#ifndef _SYS_SYSPROTO_H_ 881struct select_args { 882 int nd; 883 fd_set *in, *ou, *ex; 884 struct timeval *tv; 885}; 886#endif 887int 888sys_select(struct thread *td, struct select_args *uap) 889{ 890 struct timeval tv, *tvp; 891 int error; 892 893 if (uap->tv != NULL) { 894 error = copyin(uap->tv, &tv, sizeof(tv)); 895 if (error) 896 return (error); 897 tvp = &tv; 898 } else 899 tvp = NULL; 900 901 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 902 NFDBITS)); 903} 904 905/* 906 * In the unlikely case when user specified n greater then the last 907 * open file descriptor, check that no bits are set after the last 908 * valid fd. We must return EBADF if any is set. 909 * 910 * There are applications that rely on the behaviour. 911 * 912 * nd is fd_lastfile + 1. 913 */ 914static int 915select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 916{ 917 char *addr, *oaddr; 918 int b, i, res; 919 uint8_t bits; 920 921 if (nd >= ndu || fd_in == NULL) 922 return (0); 923 924 oaddr = NULL; 925 bits = 0; /* silence gcc */ 926 for (i = nd; i < ndu; i++) { 927 b = i / NBBY; 928#if BYTE_ORDER == LITTLE_ENDIAN 929 addr = (char *)fd_in + b; 930#else 931 addr = (char *)fd_in; 932 if (abi_nfdbits == NFDBITS) { 933 addr += rounddown(b, sizeof(fd_mask)) + 934 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 935 } else { 936 addr += rounddown(b, sizeof(uint32_t)) + 937 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 938 } 939#endif 940 if (addr != oaddr) { 941 res = fubyte(addr); 942 if (res == -1) 943 return (EFAULT); 944 oaddr = addr; 945 bits = res; 946 } 947 if ((bits & (1 << (i % NBBY))) != 0) 948 return (EBADF); 949 } 950 return (0); 951} 952 953int 954kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 955 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 956{ 957 struct filedesc *fdp; 958 /* 959 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 960 * infds with the new FD_SETSIZE of 1024, and more than enough for 961 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 962 * of 256. 963 */ 964 fd_mask s_selbits[howmany(2048, NFDBITS)]; 965 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 966 struct timeval rtv; 967 sbintime_t asbt, precision, rsbt; 968 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 969 int error, lf, ndu; 970 971 if (nd < 0) 972 return (EINVAL); 973 fdp = td->td_proc->p_fd; 974 ndu = nd; 975 lf = fdp->fd_lastfile; 976 if (nd > lf + 1) 977 nd = lf + 1; 978 979 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 980 if (error != 0) 981 return (error); 982 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 983 if (error != 0) 984 return (error); 985 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 986 if (error != 0) 987 return (error); 988 989 /* 990 * Allocate just enough bits for the non-null fd_sets. Use the 991 * preallocated auto buffer if possible. 992 */ 993 nfdbits = roundup(nd, NFDBITS); 994 ncpbytes = nfdbits / NBBY; 995 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 996 nbufbytes = 0; 997 if (fd_in != NULL) 998 nbufbytes += 2 * ncpbytes; 999 if (fd_ou != NULL) 1000 nbufbytes += 2 * ncpbytes; 1001 if (fd_ex != NULL) 1002 nbufbytes += 2 * ncpbytes; 1003 if (nbufbytes <= sizeof s_selbits) 1004 selbits = &s_selbits[0]; 1005 else 1006 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1007 1008 /* 1009 * Assign pointers into the bit buffers and fetch the input bits. 1010 * Put the output buffers together so that they can be bzeroed 1011 * together. 1012 */ 1013 sbp = selbits; 1014#define getbits(name, x) \ 1015 do { \ 1016 if (name == NULL) { \ 1017 ibits[x] = NULL; \ 1018 obits[x] = NULL; \ 1019 } else { \ 1020 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1021 obits[x] = sbp; \ 1022 sbp += ncpbytes / sizeof *sbp; \ 1023 error = copyin(name, ibits[x], ncpubytes); \ 1024 if (error != 0) \ 1025 goto done; \ 1026 bzero((char *)ibits[x] + ncpubytes, \ 1027 ncpbytes - ncpubytes); \ 1028 } \ 1029 } while (0) 1030 getbits(fd_in, 0); 1031 getbits(fd_ou, 1); 1032 getbits(fd_ex, 2); 1033#undef getbits 1034 1035#if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1036 /* 1037 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1038 * we are running under 32-bit emulation. This should be more 1039 * generic. 1040 */ 1041#define swizzle_fdset(bits) \ 1042 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1043 int i; \ 1044 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1045 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1046 } 1047#else 1048#define swizzle_fdset(bits) 1049#endif 1050 1051 /* Make sure the bit order makes it through an ABI transition */ 1052 swizzle_fdset(ibits[0]); 1053 swizzle_fdset(ibits[1]); 1054 swizzle_fdset(ibits[2]); 1055 1056 if (nbufbytes != 0) 1057 bzero(selbits, nbufbytes / 2); 1058 1059 precision = 0; 1060 if (tvp != NULL) { 1061 rtv = *tvp; 1062 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1063 rtv.tv_usec >= 1000000) { 1064 error = EINVAL; 1065 goto done; 1066 } 1067 if (!timevalisset(&rtv)) 1068 asbt = 0; 1069 else if (rtv.tv_sec <= INT32_MAX) { 1070 rsbt = tvtosbt(rtv); 1071 precision = rsbt; 1072 precision >>= tc_precexp; 1073 if (TIMESEL(&asbt, rsbt)) 1074 asbt += tc_tick_sbt; 1075 if (asbt <= INT64_MAX - rsbt) 1076 asbt += rsbt; 1077 else 1078 asbt = -1; 1079 } else 1080 asbt = -1; 1081 } else 1082 asbt = -1; 1083 seltdinit(td); 1084 /* Iterate until the timeout expires or descriptors become ready. */ 1085 for (;;) { 1086 error = selscan(td, ibits, obits, nd); 1087 if (error || td->td_retval[0] != 0) 1088 break; 1089 error = seltdwait(td, asbt, precision); 1090 if (error) 1091 break; 1092 error = selrescan(td, ibits, obits); 1093 if (error || td->td_retval[0] != 0) 1094 break; 1095 } 1096 seltdclear(td); 1097 1098done: 1099 /* select is not restarted after signals... */ 1100 if (error == ERESTART) 1101 error = EINTR; 1102 if (error == EWOULDBLOCK) 1103 error = 0; 1104 1105 /* swizzle bit order back, if necessary */ 1106 swizzle_fdset(obits[0]); 1107 swizzle_fdset(obits[1]); 1108 swizzle_fdset(obits[2]); 1109#undef swizzle_fdset 1110 1111#define putbits(name, x) \ 1112 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1113 error = error2; 1114 if (error == 0) { 1115 int error2; 1116 1117 putbits(fd_in, 0); 1118 putbits(fd_ou, 1); 1119 putbits(fd_ex, 2); 1120#undef putbits 1121 } 1122 if (selbits != &s_selbits[0]) 1123 free(selbits, M_SELECT); 1124 1125 return (error); 1126} 1127/* 1128 * Convert a select bit set to poll flags. 1129 * 1130 * The backend always returns POLLHUP/POLLERR if appropriate and we 1131 * return this as a set bit in any set. 1132 */ 1133static int select_flags[3] = { 1134 POLLRDNORM | POLLHUP | POLLERR, 1135 POLLWRNORM | POLLHUP | POLLERR, 1136 POLLRDBAND | POLLERR 1137}; 1138 1139/* 1140 * Compute the fo_poll flags required for a fd given by the index and 1141 * bit position in the fd_mask array. 1142 */ 1143static __inline int 1144selflags(fd_mask **ibits, int idx, fd_mask bit) 1145{ 1146 int flags; 1147 int msk; 1148 1149 flags = 0; 1150 for (msk = 0; msk < 3; msk++) { 1151 if (ibits[msk] == NULL) 1152 continue; 1153 if ((ibits[msk][idx] & bit) == 0) 1154 continue; 1155 flags |= select_flags[msk]; 1156 } 1157 return (flags); 1158} 1159 1160/* 1161 * Set the appropriate output bits given a mask of fired events and the 1162 * input bits originally requested. 1163 */ 1164static __inline int 1165selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1166{ 1167 int msk; 1168 int n; 1169 1170 n = 0; 1171 for (msk = 0; msk < 3; msk++) { 1172 if ((events & select_flags[msk]) == 0) 1173 continue; 1174 if (ibits[msk] == NULL) 1175 continue; 1176 if ((ibits[msk][idx] & bit) == 0) 1177 continue; 1178 /* 1179 * XXX Check for a duplicate set. This can occur because a 1180 * socket calls selrecord() twice for each poll() call 1181 * resulting in two selfds per real fd. selrescan() will 1182 * call selsetbits twice as a result. 1183 */ 1184 if ((obits[msk][idx] & bit) != 0) 1185 continue; 1186 obits[msk][idx] |= bit; 1187 n++; 1188 } 1189 1190 return (n); 1191} 1192 1193static __inline int 1194getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) 1195{ 1196 cap_rights_t rights; 1197 1198 return (fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_POLL_EVENT), 1199 0, fpp, NULL)); 1200} 1201 1202/* 1203 * Traverse the list of fds attached to this thread's seltd and check for 1204 * completion. 1205 */ 1206static int 1207selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1208{ 1209 struct filedesc *fdp; 1210 struct selinfo *si; 1211 struct seltd *stp; 1212 struct selfd *sfp; 1213 struct selfd *sfn; 1214 struct file *fp; 1215 fd_mask bit; 1216 int fd, ev, n, idx; 1217 int error; 1218 1219 fdp = td->td_proc->p_fd; 1220 stp = td->td_sel; 1221 n = 0; 1222 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1223 fd = (int)(uintptr_t)sfp->sf_cookie; 1224 si = sfp->sf_si; 1225 selfdfree(stp, sfp); 1226 /* If the selinfo wasn't cleared the event didn't fire. */ 1227 if (si != NULL) 1228 continue; 1229 error = getselfd_cap(fdp, fd, &fp); 1230 if (error) 1231 return (error); 1232 idx = fd / NFDBITS; 1233 bit = (fd_mask)1 << (fd % NFDBITS); 1234 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1235 fdrop(fp, td); 1236 if (ev != 0) 1237 n += selsetbits(ibits, obits, idx, bit, ev); 1238 } 1239 stp->st_flags = 0; 1240 td->td_retval[0] = n; 1241 return (0); 1242} 1243 1244/* 1245 * Perform the initial filedescriptor scan and register ourselves with 1246 * each selinfo. 1247 */ 1248static int 1249selscan(td, ibits, obits, nfd) 1250 struct thread *td; 1251 fd_mask **ibits, **obits; 1252 int nfd; 1253{ 1254 struct filedesc *fdp; 1255 struct file *fp; 1256 fd_mask bit; 1257 int ev, flags, end, fd; 1258 int n, idx; 1259 int error; 1260 1261 fdp = td->td_proc->p_fd; 1262 n = 0; 1263 for (idx = 0, fd = 0; fd < nfd; idx++) { 1264 end = imin(fd + NFDBITS, nfd); 1265 for (bit = 1; fd < end; bit <<= 1, fd++) { 1266 /* Compute the list of events we're interested in. */ 1267 flags = selflags(ibits, idx, bit); 1268 if (flags == 0) 1269 continue; 1270 error = getselfd_cap(fdp, fd, &fp); 1271 if (error) 1272 return (error); 1273 selfdalloc(td, (void *)(uintptr_t)fd); 1274 ev = fo_poll(fp, flags, td->td_ucred, td); 1275 fdrop(fp, td); 1276 if (ev != 0) 1277 n += selsetbits(ibits, obits, idx, bit, ev); 1278 } 1279 } 1280 1281 td->td_retval[0] = n; 1282 return (0); 1283} 1284 1285#ifndef _SYS_SYSPROTO_H_ 1286struct poll_args { 1287 struct pollfd *fds; 1288 u_int nfds; 1289 int timeout; 1290}; 1291#endif 1292int 1293sys_poll(td, uap) 1294 struct thread *td; 1295 struct poll_args *uap; 1296{ 1297 struct pollfd *bits; 1298 struct pollfd smallbits[32]; 1299 sbintime_t asbt, precision, rsbt; 1300 u_int nfds; 1301 int error; 1302 size_t ni; 1303 1304 nfds = uap->nfds; 1305 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1306 return (EINVAL); 1307 ni = nfds * sizeof(struct pollfd); 1308 if (ni > sizeof(smallbits)) 1309 bits = malloc(ni, M_TEMP, M_WAITOK); 1310 else 1311 bits = smallbits; 1312 error = copyin(uap->fds, bits, ni); 1313 if (error) 1314 goto done; 1315 precision = 0; 1316 if (uap->timeout != INFTIM) { 1317 if (uap->timeout < 0) { 1318 error = EINVAL; 1319 goto done; 1320 } 1321 if (uap->timeout == 0) 1322 asbt = 0; 1323 else { 1324 rsbt = SBT_1MS * uap->timeout; 1325 precision = rsbt; 1326 precision >>= tc_precexp; 1327 if (TIMESEL(&asbt, rsbt)) 1328 asbt += tc_tick_sbt; 1329 asbt += rsbt; 1330 } 1331 } else 1332 asbt = -1; 1333 seltdinit(td); 1334 /* Iterate until the timeout expires or descriptors become ready. */ 1335 for (;;) { 1336 error = pollscan(td, bits, nfds); 1337 if (error || td->td_retval[0] != 0) 1338 break; 1339 error = seltdwait(td, asbt, precision); 1340 if (error) 1341 break; 1342 error = pollrescan(td); 1343 if (error || td->td_retval[0] != 0) 1344 break; 1345 } 1346 seltdclear(td); 1347 1348done: 1349 /* poll is not restarted after signals... */ 1350 if (error == ERESTART) 1351 error = EINTR; 1352 if (error == EWOULDBLOCK) 1353 error = 0; 1354 if (error == 0) { 1355 error = pollout(td, bits, uap->fds, nfds); 1356 if (error) 1357 goto out; 1358 } 1359out: 1360 if (ni > sizeof(smallbits)) 1361 free(bits, M_TEMP); 1362 return (error); 1363} 1364 1365static int 1366pollrescan(struct thread *td) 1367{ 1368 struct seltd *stp; 1369 struct selfd *sfp; 1370 struct selfd *sfn; 1371 struct selinfo *si; 1372 struct filedesc *fdp; 1373 struct file *fp; 1374 struct pollfd *fd; 1375#ifdef CAPABILITIES 1376 cap_rights_t rights; 1377#endif 1378 int n; 1379 1380 n = 0; 1381 fdp = td->td_proc->p_fd; 1382 stp = td->td_sel; 1383 FILEDESC_SLOCK(fdp); 1384 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1385 fd = (struct pollfd *)sfp->sf_cookie; 1386 si = sfp->sf_si; 1387 selfdfree(stp, sfp); 1388 /* If the selinfo wasn't cleared the event didn't fire. */ 1389 if (si != NULL) 1390 continue; 1391 fp = fdp->fd_ofiles[fd->fd].fde_file; 1392#ifdef CAPABILITIES 1393 if (fp == NULL || 1394 cap_check(cap_rights(fdp, fd->fd), 1395 cap_rights_init(&rights, CAP_POLL_EVENT)) != 0) 1396#else 1397 if (fp == NULL) 1398#endif 1399 { 1400 fd->revents = POLLNVAL; 1401 n++; 1402 continue; 1403 } 1404 1405 /* 1406 * Note: backend also returns POLLHUP and 1407 * POLLERR if appropriate. 1408 */ 1409 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1410 if (fd->revents != 0) 1411 n++; 1412 } 1413 FILEDESC_SUNLOCK(fdp); 1414 stp->st_flags = 0; 1415 td->td_retval[0] = n; 1416 return (0); 1417} 1418 1419 1420static int 1421pollout(td, fds, ufds, nfd) 1422 struct thread *td; 1423 struct pollfd *fds; 1424 struct pollfd *ufds; 1425 u_int nfd; 1426{ 1427 int error = 0; 1428 u_int i = 0; 1429 u_int n = 0; 1430 1431 for (i = 0; i < nfd; i++) { 1432 error = copyout(&fds->revents, &ufds->revents, 1433 sizeof(ufds->revents)); 1434 if (error) 1435 return (error); 1436 if (fds->revents != 0) 1437 n++; 1438 fds++; 1439 ufds++; 1440 } 1441 td->td_retval[0] = n; 1442 return (0); 1443} 1444 1445static int 1446pollscan(td, fds, nfd) 1447 struct thread *td; 1448 struct pollfd *fds; 1449 u_int nfd; 1450{ 1451 struct filedesc *fdp = td->td_proc->p_fd; 1452 struct file *fp; 1453#ifdef CAPABILITIES 1454 cap_rights_t rights; 1455#endif 1456 int i, n = 0; 1457 1458 FILEDESC_SLOCK(fdp); 1459 for (i = 0; i < nfd; i++, fds++) { 1460 if (fds->fd >= fdp->fd_nfiles) { 1461 fds->revents = POLLNVAL; 1462 n++; 1463 } else if (fds->fd < 0) { 1464 fds->revents = 0; 1465 } else { 1466 fp = fdp->fd_ofiles[fds->fd].fde_file; 1467#ifdef CAPABILITIES 1468 if (fp == NULL || 1469 cap_check(cap_rights(fdp, fds->fd), 1470 cap_rights_init(&rights, CAP_POLL_EVENT)) != 0) 1471#else 1472 if (fp == NULL) 1473#endif 1474 { 1475 fds->revents = POLLNVAL; 1476 n++; 1477 } else { 1478 /* 1479 * Note: backend also returns POLLHUP and 1480 * POLLERR if appropriate. 1481 */ 1482 selfdalloc(td, fds); 1483 fds->revents = fo_poll(fp, fds->events, 1484 td->td_ucred, td); 1485 /* 1486 * POSIX requires POLLOUT to be never 1487 * set simultaneously with POLLHUP. 1488 */ 1489 if ((fds->revents & POLLHUP) != 0) 1490 fds->revents &= ~POLLOUT; 1491 1492 if (fds->revents != 0) 1493 n++; 1494 } 1495 } 1496 } 1497 FILEDESC_SUNLOCK(fdp); 1498 td->td_retval[0] = n; 1499 return (0); 1500} 1501 1502/* 1503 * OpenBSD poll system call. 1504 * 1505 * XXX this isn't quite a true representation.. OpenBSD uses select ops. 1506 */ 1507#ifndef _SYS_SYSPROTO_H_ 1508struct openbsd_poll_args { 1509 struct pollfd *fds; 1510 u_int nfds; 1511 int timeout; 1512}; 1513#endif 1514int 1515sys_openbsd_poll(td, uap) 1516 register struct thread *td; 1517 register struct openbsd_poll_args *uap; 1518{ 1519 return (sys_poll(td, (struct poll_args *)uap)); 1520} 1521 1522/* 1523 * XXX This was created specifically to support netncp and netsmb. This 1524 * allows the caller to specify a socket to wait for events on. It returns 1525 * 0 if any events matched and an error otherwise. There is no way to 1526 * determine which events fired. 1527 */ 1528int 1529selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1530{ 1531 struct timeval rtv; 1532 sbintime_t asbt, precision, rsbt; 1533 int error; 1534 1535 precision = 0; /* stupid gcc! */ 1536 if (tvp != NULL) { 1537 rtv = *tvp; 1538 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1539 rtv.tv_usec >= 1000000) 1540 return (EINVAL); 1541 if (!timevalisset(&rtv)) 1542 asbt = 0; 1543 else if (rtv.tv_sec <= INT32_MAX) { 1544 rsbt = tvtosbt(rtv); 1545 precision = rsbt; 1546 precision >>= tc_precexp; 1547 if (TIMESEL(&asbt, rsbt)) 1548 asbt += tc_tick_sbt; 1549 if (asbt <= INT64_MAX - rsbt) 1550 asbt += rsbt; 1551 else 1552 asbt = -1; 1553 } else 1554 asbt = -1; 1555 } else 1556 asbt = -1; 1557 seltdinit(td); 1558 /* 1559 * Iterate until the timeout expires or the socket becomes ready. 1560 */ 1561 for (;;) { 1562 selfdalloc(td, NULL); 1563 error = sopoll(so, events, NULL, td); 1564 /* error here is actually the ready events. */ 1565 if (error) 1566 return (0); 1567 error = seltdwait(td, asbt, precision); 1568 if (error) 1569 break; 1570 } 1571 seltdclear(td); 1572 /* XXX Duplicates ncp/smb behavior. */ 1573 if (error == ERESTART) 1574 error = 0; 1575 return (error); 1576} 1577 1578/* 1579 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1580 * have two select sets, one for read and another for write. 1581 */ 1582static void 1583selfdalloc(struct thread *td, void *cookie) 1584{ 1585 struct seltd *stp; 1586 1587 stp = td->td_sel; 1588 if (stp->st_free1 == NULL) 1589 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1590 stp->st_free1->sf_td = stp; 1591 stp->st_free1->sf_cookie = cookie; 1592 if (stp->st_free2 == NULL) 1593 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1594 stp->st_free2->sf_td = stp; 1595 stp->st_free2->sf_cookie = cookie; 1596} 1597 1598static void 1599selfdfree(struct seltd *stp, struct selfd *sfp) 1600{ 1601 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1602 mtx_lock(sfp->sf_mtx); 1603 if (sfp->sf_si) 1604 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1605 mtx_unlock(sfp->sf_mtx); 1606 uma_zfree(selfd_zone, sfp); 1607} 1608 1609/* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1610void 1611seldrain(sip) 1612 struct selinfo *sip; 1613{ 1614 1615 /* 1616 * This feature is already provided by doselwakeup(), thus it is 1617 * enough to go for it. 1618 * Eventually, the context, should take care to avoid races 1619 * between thread calling select()/poll() and file descriptor 1620 * detaching, but, again, the races are just the same as 1621 * selwakeup(). 1622 */ 1623 doselwakeup(sip, -1); 1624} 1625 1626/* 1627 * Record a select request. 1628 */ 1629void 1630selrecord(selector, sip) 1631 struct thread *selector; 1632 struct selinfo *sip; 1633{ 1634 struct selfd *sfp; 1635 struct seltd *stp; 1636 struct mtx *mtxp; 1637 1638 stp = selector->td_sel; 1639 /* 1640 * Don't record when doing a rescan. 1641 */ 1642 if (stp->st_flags & SELTD_RESCAN) 1643 return; 1644 /* 1645 * Grab one of the preallocated descriptors. 1646 */ 1647 sfp = NULL; 1648 if ((sfp = stp->st_free1) != NULL) 1649 stp->st_free1 = NULL; 1650 else if ((sfp = stp->st_free2) != NULL) 1651 stp->st_free2 = NULL; 1652 else 1653 panic("selrecord: No free selfd on selq"); 1654 mtxp = sip->si_mtx; 1655 if (mtxp == NULL) 1656 mtxp = mtx_pool_find(mtxpool_select, sip); 1657 /* 1658 * Initialize the sfp and queue it in the thread. 1659 */ 1660 sfp->sf_si = sip; 1661 sfp->sf_mtx = mtxp; 1662 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1663 /* 1664 * Now that we've locked the sip, check for initialization. 1665 */ 1666 mtx_lock(mtxp); 1667 if (sip->si_mtx == NULL) { 1668 sip->si_mtx = mtxp; 1669 TAILQ_INIT(&sip->si_tdlist); 1670 } 1671 /* 1672 * Add this thread to the list of selfds listening on this selinfo. 1673 */ 1674 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1675 mtx_unlock(sip->si_mtx); 1676} 1677 1678/* Wake up a selecting thread. */ 1679void 1680selwakeup(sip) 1681 struct selinfo *sip; 1682{ 1683 doselwakeup(sip, -1); 1684} 1685 1686/* Wake up a selecting thread, and set its priority. */ 1687void 1688selwakeuppri(sip, pri) 1689 struct selinfo *sip; 1690 int pri; 1691{ 1692 doselwakeup(sip, pri); 1693} 1694 1695/* 1696 * Do a wakeup when a selectable event occurs. 1697 */ 1698static void 1699doselwakeup(sip, pri) 1700 struct selinfo *sip; 1701 int pri; 1702{ 1703 struct selfd *sfp; 1704 struct selfd *sfn; 1705 struct seltd *stp; 1706 1707 /* If it's not initialized there can't be any waiters. */ 1708 if (sip->si_mtx == NULL) 1709 return; 1710 /* 1711 * Locking the selinfo locks all selfds associated with it. 1712 */ 1713 mtx_lock(sip->si_mtx); 1714 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1715 /* 1716 * Once we remove this sfp from the list and clear the 1717 * sf_si seltdclear will know to ignore this si. 1718 */ 1719 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1720 sfp->sf_si = NULL; 1721 stp = sfp->sf_td; 1722 mtx_lock(&stp->st_mtx); 1723 stp->st_flags |= SELTD_PENDING; 1724 cv_broadcastpri(&stp->st_wait, pri); 1725 mtx_unlock(&stp->st_mtx); 1726 } 1727 mtx_unlock(sip->si_mtx); 1728} 1729 1730static void 1731seltdinit(struct thread *td) 1732{ 1733 struct seltd *stp; 1734 1735 if ((stp = td->td_sel) != NULL) 1736 goto out; 1737 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1738 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1739 cv_init(&stp->st_wait, "select"); 1740out: 1741 stp->st_flags = 0; 1742 STAILQ_INIT(&stp->st_selq); 1743} 1744 1745static int 1746seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1747{ 1748 struct seltd *stp; 1749 int error; 1750 1751 stp = td->td_sel; 1752 /* 1753 * An event of interest may occur while we do not hold the seltd 1754 * locked so check the pending flag before we sleep. 1755 */ 1756 mtx_lock(&stp->st_mtx); 1757 /* 1758 * Any further calls to selrecord will be a rescan. 1759 */ 1760 stp->st_flags |= SELTD_RESCAN; 1761 if (stp->st_flags & SELTD_PENDING) { 1762 mtx_unlock(&stp->st_mtx); 1763 return (0); 1764 } 1765 if (sbt == 0) 1766 error = EWOULDBLOCK; 1767 else if (sbt != -1) 1768 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 1769 sbt, precision, C_ABSOLUTE); 1770 else 1771 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1772 mtx_unlock(&stp->st_mtx); 1773 1774 return (error); 1775} 1776 1777void 1778seltdfini(struct thread *td) 1779{ 1780 struct seltd *stp; 1781 1782 stp = td->td_sel; 1783 if (stp == NULL) 1784 return; 1785 if (stp->st_free1) 1786 uma_zfree(selfd_zone, stp->st_free1); 1787 if (stp->st_free2) 1788 uma_zfree(selfd_zone, stp->st_free2); 1789 td->td_sel = NULL; 1790 free(stp, M_SELECT); 1791} 1792 1793/* 1794 * Remove the references to the thread from all of the objects we were 1795 * polling. 1796 */ 1797static void 1798seltdclear(struct thread *td) 1799{ 1800 struct seltd *stp; 1801 struct selfd *sfp; 1802 struct selfd *sfn; 1803 1804 stp = td->td_sel; 1805 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1806 selfdfree(stp, sfp); 1807 stp->st_flags = 0; 1808} 1809 1810static void selectinit(void *); 1811SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1812static void 1813selectinit(void *dummy __unused) 1814{ 1815 1816 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, 1817 NULL, NULL, UMA_ALIGN_PTR, 0); 1818 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 1819} 1820