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