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/capsicum.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 78 int iosize_max_clamp = 0; 79 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, 80 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); 81 int devfs_iosize_max_clamp = 1; 82 SYSCTL_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 */ 90 CTASSERT(sizeof(register_t) >= sizeof(size_t)); 91 92 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 93 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); 94 MALLOC_DEFINE(M_IOV, "iov", "large iov's"); 95 96 static int pollout(struct thread *, struct pollfd *, struct pollfd *, 97 u_int); 98 static int pollscan(struct thread *, struct pollfd *, u_int); 99 static int pollrescan(struct thread *); 100 static int selscan(struct thread *, fd_mask **, fd_mask **, int); 101 static int selrescan(struct thread *, fd_mask **, fd_mask **); 102 static void selfdalloc(struct thread *, void *); 103 static void selfdfree(struct seltd *, struct selfd *); 104 static int dofileread(struct thread *, int, struct file *, struct uio *, 105 off_t, int); 106 static int dofilewrite(struct thread *, int, struct file *, struct uio *, 107 off_t, int); 108 static void doselwakeup(struct selinfo *, int); 109 static void seltdinit(struct thread *); 110 static int seltdwait(struct thread *, sbintime_t, sbintime_t); 111 static 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 */ 119 struct 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 */ 135 struct 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 }; 143 144 static uma_zone_t selfd_zone; 145 static struct mtx_pool *mtxpool_select; 146 147 #ifndef _SYS_SYSPROTO_H_ 148 struct read_args { 149 int fd; 150 void *buf; 151 size_t nbyte; 152 }; 153 #endif 154 int 155 sys_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_ 179 struct pread_args { 180 int fd; 181 void *buf; 182 size_t nbyte; 183 int pad; 184 off_t offset; 185 }; 186 #endif 187 int 188 sys_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 } 207 208 int 209 freebsd6_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_ 226 struct readv_args { 227 int fd; 228 struct iovec *iovp; 229 u_int iovcnt; 230 }; 231 #endif 232 int 233 sys_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 } 245 246 int 247 kern_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_ 265 struct preadv_args { 266 int fd; 267 struct iovec *iovp; 268 u_int iovcnt; 269 off_t offset; 270 }; 271 #endif 272 int 273 sys_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 } 285 286 int 287 kern_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 */ 314 static int 315 dofileread(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_ 359 struct write_args { 360 int fd; 361 const void *buf; 362 size_t nbyte; 363 }; 364 #endif 365 int 366 sys_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_ 390 struct pwrite_args { 391 int fd; 392 const void *buf; 393 size_t nbyte; 394 int pad; 395 off_t offset; 396 }; 397 #endif 398 int 399 sys_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 } 418 419 int 420 freebsd6_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_ 437 struct writev_args { 438 int fd; 439 struct iovec *iovp; 440 u_int iovcnt; 441 }; 442 #endif 443 int 444 sys_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 } 456 457 int 458 kern_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_ 476 struct pwritev_args { 477 int fd; 478 struct iovec *iovp; 479 u_int iovcnt; 480 off_t offset; 481 }; 482 #endif 483 int 484 sys_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 } 496 497 int 498 kern_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 */ 525 static int 526 dofilewrite(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 */ 579 int 580 kern_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_ 606 struct ftruncate_args { 607 int fd; 608 int pad; 609 off_t length; 610 }; 611 #endif 612 int 613 sys_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_ 623 struct oftruncate_args { 624 int fd; 625 long length; 626 }; 627 #endif 628 int 629 oftruncate(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_ 639 struct ioctl_args { 640 int fd; 641 u_long com; 642 caddr_t data; 643 }; 644 #endif 645 /* ARGSUSED */ 646 int 647 sys_ioctl(struct thread *td, struct ioctl_args *uap) 648 { 649 u_long com; 650 int arg, error; 651 u_int size; 652 u_char smalldata[128]; 653 caddr_t data; 654 655 if (uap->com > 0xffffffff) { 656 printf( 657 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 658 td->td_proc->p_pid, td->td_name, uap->com); 659 uap->com &= 0xffffffff; 660 } 661 com = uap->com; 662 663 /* 664 * Interpret high order word to find amount of data to be 665 * copied to/from the user's address space. 666 */ 667 size = IOCPARM_LEN(com); 668 if ((size > IOCPARM_MAX) || 669 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 670 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 671 ((com & IOC_OUT) && size == 0) || 672 #else 673 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 674 #endif 675 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 676 return (ENOTTY); 677 678 if (size > 0) { 679 if (com & IOC_VOID) { 680 /* Integer argument. */ 681 arg = (intptr_t)uap->data; 682 data = (void *)&arg; 683 size = 0; 684 } else { 685 if (size <= sizeof(smalldata)) 686 data = smalldata; 687 else 688 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 689 } 690 } else 691 data = (void *)&uap->data; 692 if (com & IOC_IN) { 693 error = copyin(uap->data, data, (u_int)size); 694 if (error != 0) 695 goto out; 696 } else if (com & IOC_OUT) { 697 /* 698 * Zero the buffer so the user always 699 * gets back something deterministic. 700 */ 701 bzero(data, size); 702 } 703 704 error = kern_ioctl(td, uap->fd, com, data); 705 706 if (error == 0 && (com & IOC_OUT)) 707 error = copyout(data, uap->data, (u_int)size); 708 709 out: 710 if (size > 0 && data != (caddr_t)&smalldata) 711 free(data, M_IOCTLOPS); 712 return (error); 713 } 714 715 int 716 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 717 { 718 struct file *fp; 719 struct filedesc *fdp; 720 #ifndef CAPABILITIES 721 cap_rights_t rights; 722 #endif 723 int error, tmp, locked; 724 725 AUDIT_ARG_FD(fd); 726 AUDIT_ARG_CMD(com); 727 728 fdp = td->td_proc->p_fd; 729 730 switch (com) { 731 case FIONCLEX: 732 case FIOCLEX: 733 FILEDESC_XLOCK(fdp); 734 locked = LA_XLOCKED; 735 break; 736 default: 737 #ifdef CAPABILITIES 738 FILEDESC_SLOCK(fdp); 739 locked = LA_SLOCKED; 740 #else 741 locked = LA_UNLOCKED; 742 #endif 743 break; 744 } 745 746 #ifdef CAPABILITIES 747 if ((fp = fget_locked(fdp, fd)) == NULL) { 748 error = EBADF; 749 goto out; 750 } 751 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 752 fp = NULL; /* fhold() was not called yet */ 753 goto out; 754 } 755 fhold(fp); 756 if (locked == LA_SLOCKED) { 757 FILEDESC_SUNLOCK(fdp); 758 locked = LA_UNLOCKED; 759 } 760 #else 761 error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp); 762 if (error != 0) { 763 fp = NULL; 764 goto out; 765 } 766 #endif 767 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 768 error = EBADF; 769 goto out; 770 } 771 772 switch (com) { 773 case FIONCLEX: 774 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 775 goto out; 776 case FIOCLEX: 777 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 778 goto out; 779 case FIONBIO: 780 if ((tmp = *(int *)data)) 781 atomic_set_int(&fp->f_flag, FNONBLOCK); 782 else 783 atomic_clear_int(&fp->f_flag, FNONBLOCK); 784 data = (void *)&tmp; 785 break; 786 case FIOASYNC: 787 if ((tmp = *(int *)data)) 788 atomic_set_int(&fp->f_flag, FASYNC); 789 else 790 atomic_clear_int(&fp->f_flag, FASYNC); 791 data = (void *)&tmp; 792 break; 793 } 794 795 error = fo_ioctl(fp, com, data, td->td_ucred, td); 796 out: 797 switch (locked) { 798 case LA_XLOCKED: 799 FILEDESC_XUNLOCK(fdp); 800 break; 801 #ifdef CAPABILITIES 802 case LA_SLOCKED: 803 FILEDESC_SUNLOCK(fdp); 804 break; 805 #endif 806 default: 807 FILEDESC_UNLOCK_ASSERT(fdp); 808 break; 809 } 810 if (fp != NULL) 811 fdrop(fp, td); 812 return (error); 813 } 814 815 int 816 poll_no_poll(int events) 817 { 818 /* 819 * Return true for read/write. If the user asked for something 820 * special, return POLLNVAL, so that clients have a way of 821 * determining reliably whether or not the extended 822 * functionality is present without hard-coding knowledge 823 * of specific filesystem implementations. 824 */ 825 if (events & ~POLLSTANDARD) 826 return (POLLNVAL); 827 828 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 829 } 830 831 int 832 sys_pselect(struct thread *td, struct pselect_args *uap) 833 { 834 struct timespec ts; 835 struct timeval tv, *tvp; 836 sigset_t set, *uset; 837 int error; 838 839 if (uap->ts != NULL) { 840 error = copyin(uap->ts, &ts, sizeof(ts)); 841 if (error != 0) 842 return (error); 843 TIMESPEC_TO_TIMEVAL(&tv, &ts); 844 tvp = &tv; 845 } else 846 tvp = NULL; 847 if (uap->sm != NULL) { 848 error = copyin(uap->sm, &set, sizeof(set)); 849 if (error != 0) 850 return (error); 851 uset = &set; 852 } else 853 uset = NULL; 854 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 855 uset, NFDBITS)); 856 } 857 858 int 859 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 860 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 861 { 862 int error; 863 864 if (uset != NULL) { 865 error = kern_sigprocmask(td, SIG_SETMASK, uset, 866 &td->td_oldsigmask, 0); 867 if (error != 0) 868 return (error); 869 td->td_pflags |= TDP_OLDMASK; 870 /* 871 * Make sure that ast() is called on return to 872 * usermode and TDP_OLDMASK is cleared, restoring old 873 * sigmask. 874 */ 875 thread_lock(td); 876 td->td_flags |= TDF_ASTPENDING; 877 thread_unlock(td); 878 } 879 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 880 return (error); 881 } 882 883 #ifndef _SYS_SYSPROTO_H_ 884 struct select_args { 885 int nd; 886 fd_set *in, *ou, *ex; 887 struct timeval *tv; 888 }; 889 #endif 890 int 891 sys_select(struct thread *td, struct select_args *uap) 892 { 893 struct timeval tv, *tvp; 894 int error; 895 896 if (uap->tv != NULL) { 897 error = copyin(uap->tv, &tv, sizeof(tv)); 898 if (error) 899 return (error); 900 tvp = &tv; 901 } else 902 tvp = NULL; 903 904 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 905 NFDBITS)); 906 } 907 908 /* 909 * In the unlikely case when user specified n greater then the last 910 * open file descriptor, check that no bits are set after the last 911 * valid fd. We must return EBADF if any is set. 912 * 913 * There are applications that rely on the behaviour. 914 * 915 * nd is fd_lastfile + 1. 916 */ 917 static int 918 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 919 { 920 char *addr, *oaddr; 921 int b, i, res; 922 uint8_t bits; 923 924 if (nd >= ndu || fd_in == NULL) 925 return (0); 926 927 oaddr = NULL; 928 bits = 0; /* silence gcc */ 929 for (i = nd; i < ndu; i++) { 930 b = i / NBBY; 931 #if BYTE_ORDER == LITTLE_ENDIAN 932 addr = (char *)fd_in + b; 933 #else 934 addr = (char *)fd_in; 935 if (abi_nfdbits == NFDBITS) { 936 addr += rounddown(b, sizeof(fd_mask)) + 937 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 938 } else { 939 addr += rounddown(b, sizeof(uint32_t)) + 940 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 941 } 942 #endif 943 if (addr != oaddr) { 944 res = fubyte(addr); 945 if (res == -1) 946 return (EFAULT); 947 oaddr = addr; 948 bits = res; 949 } 950 if ((bits & (1 << (i % NBBY))) != 0) 951 return (EBADF); 952 } 953 return (0); 954 } 955 956 int 957 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 958 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 959 { 960 struct filedesc *fdp; 961 /* 962 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 963 * infds with the new FD_SETSIZE of 1024, and more than enough for 964 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 965 * of 256. 966 */ 967 fd_mask s_selbits[howmany(2048, NFDBITS)]; 968 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 969 struct timeval rtv; 970 sbintime_t asbt, precision, rsbt; 971 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 972 int error, lf, ndu; 973 974 if (nd < 0) 975 return (EINVAL); 976 fdp = td->td_proc->p_fd; 977 ndu = nd; 978 lf = fdp->fd_lastfile; 979 if (nd > lf + 1) 980 nd = lf + 1; 981 982 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 983 if (error != 0) 984 return (error); 985 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 986 if (error != 0) 987 return (error); 988 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 989 if (error != 0) 990 return (error); 991 992 /* 993 * Allocate just enough bits for the non-null fd_sets. Use the 994 * preallocated auto buffer if possible. 995 */ 996 nfdbits = roundup(nd, NFDBITS); 997 ncpbytes = nfdbits / NBBY; 998 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 999 nbufbytes = 0; 1000 if (fd_in != NULL) 1001 nbufbytes += 2 * ncpbytes; 1002 if (fd_ou != NULL) 1003 nbufbytes += 2 * ncpbytes; 1004 if (fd_ex != NULL) 1005 nbufbytes += 2 * ncpbytes; 1006 if (nbufbytes <= sizeof s_selbits) 1007 selbits = &s_selbits[0]; 1008 else 1009 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1010 1011 /* 1012 * Assign pointers into the bit buffers and fetch the input bits. 1013 * Put the output buffers together so that they can be bzeroed 1014 * together. 1015 */ 1016 sbp = selbits; 1017 #define getbits(name, x) \ 1018 do { \ 1019 if (name == NULL) { \ 1020 ibits[x] = NULL; \ 1021 obits[x] = NULL; \ 1022 } else { \ 1023 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1024 obits[x] = sbp; \ 1025 sbp += ncpbytes / sizeof *sbp; \ 1026 error = copyin(name, ibits[x], ncpubytes); \ 1027 if (error != 0) \ 1028 goto done; \ 1029 bzero((char *)ibits[x] + ncpubytes, \ 1030 ncpbytes - ncpubytes); \ 1031 } \ 1032 } while (0) 1033 getbits(fd_in, 0); 1034 getbits(fd_ou, 1); 1035 getbits(fd_ex, 2); 1036 #undef getbits 1037 1038 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1039 /* 1040 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1041 * we are running under 32-bit emulation. This should be more 1042 * generic. 1043 */ 1044 #define swizzle_fdset(bits) \ 1045 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1046 int i; \ 1047 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1048 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1049 } 1050 #else 1051 #define swizzle_fdset(bits) 1052 #endif 1053 1054 /* Make sure the bit order makes it through an ABI transition */ 1055 swizzle_fdset(ibits[0]); 1056 swizzle_fdset(ibits[1]); 1057 swizzle_fdset(ibits[2]); 1058 1059 if (nbufbytes != 0) 1060 bzero(selbits, nbufbytes / 2); 1061 1062 precision = 0; 1063 if (tvp != NULL) { 1064 rtv = *tvp; 1065 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1066 rtv.tv_usec >= 1000000) { 1067 error = EINVAL; 1068 goto done; 1069 } 1070 if (!timevalisset(&rtv)) 1071 asbt = 0; 1072 else if (rtv.tv_sec <= INT32_MAX) { 1073 rsbt = tvtosbt(rtv); 1074 precision = rsbt; 1075 precision >>= tc_precexp; 1076 if (TIMESEL(&asbt, rsbt)) 1077 asbt += tc_tick_sbt; 1078 if (asbt <= SBT_MAX - rsbt) 1079 asbt += rsbt; 1080 else 1081 asbt = -1; 1082 } else 1083 asbt = -1; 1084 } else 1085 asbt = -1; 1086 seltdinit(td); 1087 /* Iterate until the timeout expires or descriptors become ready. */ 1088 for (;;) { 1089 error = selscan(td, ibits, obits, nd); 1090 if (error || td->td_retval[0] != 0) 1091 break; 1092 error = seltdwait(td, asbt, precision); 1093 if (error) 1094 break; 1095 error = selrescan(td, ibits, obits); 1096 if (error || td->td_retval[0] != 0) 1097 break; 1098 } 1099 seltdclear(td); 1100 1101 done: 1102 /* select is not restarted after signals... */ 1103 if (error == ERESTART) 1104 error = EINTR; 1105 if (error == EWOULDBLOCK) 1106 error = 0; 1107 1108 /* swizzle bit order back, if necessary */ 1109 swizzle_fdset(obits[0]); 1110 swizzle_fdset(obits[1]); 1111 swizzle_fdset(obits[2]); 1112 #undef swizzle_fdset 1113 1114 #define putbits(name, x) \ 1115 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1116 error = error2; 1117 if (error == 0) { 1118 int error2; 1119 1120 putbits(fd_in, 0); 1121 putbits(fd_ou, 1); 1122 putbits(fd_ex, 2); 1123 #undef putbits 1124 } 1125 if (selbits != &s_selbits[0]) 1126 free(selbits, M_SELECT); 1127 1128 return (error); 1129 } 1130 /* 1131 * Convert a select bit set to poll flags. 1132 * 1133 * The backend always returns POLLHUP/POLLERR if appropriate and we 1134 * return this as a set bit in any set. 1135 */ 1136 static int select_flags[3] = { 1137 POLLRDNORM | POLLHUP | POLLERR, 1138 POLLWRNORM | POLLHUP | POLLERR, 1139 POLLRDBAND | POLLERR 1140 }; 1141 1142 /* 1143 * Compute the fo_poll flags required for a fd given by the index and 1144 * bit position in the fd_mask array. 1145 */ 1146 static __inline int 1147 selflags(fd_mask **ibits, int idx, fd_mask bit) 1148 { 1149 int flags; 1150 int msk; 1151 1152 flags = 0; 1153 for (msk = 0; msk < 3; msk++) { 1154 if (ibits[msk] == NULL) 1155 continue; 1156 if ((ibits[msk][idx] & bit) == 0) 1157 continue; 1158 flags |= select_flags[msk]; 1159 } 1160 return (flags); 1161 } 1162 1163 /* 1164 * Set the appropriate output bits given a mask of fired events and the 1165 * input bits originally requested. 1166 */ 1167 static __inline int 1168 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1169 { 1170 int msk; 1171 int n; 1172 1173 n = 0; 1174 for (msk = 0; msk < 3; msk++) { 1175 if ((events & select_flags[msk]) == 0) 1176 continue; 1177 if (ibits[msk] == NULL) 1178 continue; 1179 if ((ibits[msk][idx] & bit) == 0) 1180 continue; 1181 /* 1182 * XXX Check for a duplicate set. This can occur because a 1183 * socket calls selrecord() twice for each poll() call 1184 * resulting in two selfds per real fd. selrescan() will 1185 * call selsetbits twice as a result. 1186 */ 1187 if ((obits[msk][idx] & bit) != 0) 1188 continue; 1189 obits[msk][idx] |= bit; 1190 n++; 1191 } 1192 1193 return (n); 1194 } 1195 1196 static __inline int 1197 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) 1198 { 1199 cap_rights_t rights; 1200 1201 cap_rights_init(&rights, CAP_EVENT); 1202 1203 return (fget_unlocked(fdp, fd, &rights, 0, fpp, NULL)); 1204 } 1205 1206 /* 1207 * Traverse the list of fds attached to this thread's seltd and check for 1208 * completion. 1209 */ 1210 static int 1211 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1212 { 1213 struct filedesc *fdp; 1214 struct selinfo *si; 1215 struct seltd *stp; 1216 struct selfd *sfp; 1217 struct selfd *sfn; 1218 struct file *fp; 1219 fd_mask bit; 1220 int fd, ev, n, idx; 1221 int error; 1222 1223 fdp = td->td_proc->p_fd; 1224 stp = td->td_sel; 1225 n = 0; 1226 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1227 fd = (int)(uintptr_t)sfp->sf_cookie; 1228 si = sfp->sf_si; 1229 selfdfree(stp, sfp); 1230 /* If the selinfo wasn't cleared the event didn't fire. */ 1231 if (si != NULL) 1232 continue; 1233 error = getselfd_cap(fdp, fd, &fp); 1234 if (error) 1235 return (error); 1236 idx = fd / NFDBITS; 1237 bit = (fd_mask)1 << (fd % NFDBITS); 1238 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1239 fdrop(fp, td); 1240 if (ev != 0) 1241 n += selsetbits(ibits, obits, idx, bit, ev); 1242 } 1243 stp->st_flags = 0; 1244 td->td_retval[0] = n; 1245 return (0); 1246 } 1247 1248 /* 1249 * Perform the initial filedescriptor scan and register ourselves with 1250 * each selinfo. 1251 */ 1252 static int 1253 selscan(td, ibits, obits, nfd) 1254 struct thread *td; 1255 fd_mask **ibits, **obits; 1256 int nfd; 1257 { 1258 struct filedesc *fdp; 1259 struct file *fp; 1260 fd_mask bit; 1261 int ev, flags, end, fd; 1262 int n, idx; 1263 int error; 1264 1265 fdp = td->td_proc->p_fd; 1266 n = 0; 1267 for (idx = 0, fd = 0; fd < nfd; idx++) { 1268 end = imin(fd + NFDBITS, nfd); 1269 for (bit = 1; fd < end; bit <<= 1, fd++) { 1270 /* Compute the list of events we're interested in. */ 1271 flags = selflags(ibits, idx, bit); 1272 if (flags == 0) 1273 continue; 1274 error = getselfd_cap(fdp, fd, &fp); 1275 if (error) 1276 return (error); 1277 selfdalloc(td, (void *)(uintptr_t)fd); 1278 ev = fo_poll(fp, flags, td->td_ucred, td); 1279 fdrop(fp, td); 1280 if (ev != 0) 1281 n += selsetbits(ibits, obits, idx, bit, ev); 1282 } 1283 } 1284 1285 td->td_retval[0] = n; 1286 return (0); 1287 } 1288 1289 #ifndef _SYS_SYSPROTO_H_ 1290 struct poll_args { 1291 struct pollfd *fds; 1292 u_int nfds; 1293 int timeout; 1294 }; 1295 #endif 1296 int 1297 sys_poll(td, uap) 1298 struct thread *td; 1299 struct poll_args *uap; 1300 { 1301 struct pollfd *bits; 1302 struct pollfd smallbits[32]; 1303 sbintime_t asbt, precision, rsbt; 1304 u_int nfds; 1305 int error; 1306 size_t ni; 1307 1308 nfds = uap->nfds; 1309 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1310 return (EINVAL); 1311 ni = nfds * sizeof(struct pollfd); 1312 if (ni > sizeof(smallbits)) 1313 bits = malloc(ni, M_TEMP, M_WAITOK); 1314 else 1315 bits = smallbits; 1316 error = copyin(uap->fds, bits, ni); 1317 if (error) 1318 goto done; 1319 precision = 0; 1320 if (uap->timeout != INFTIM) { 1321 if (uap->timeout < 0) { 1322 error = EINVAL; 1323 goto done; 1324 } 1325 if (uap->timeout == 0) 1326 asbt = 0; 1327 else { 1328 rsbt = SBT_1MS * uap->timeout; 1329 precision = rsbt; 1330 precision >>= tc_precexp; 1331 if (TIMESEL(&asbt, rsbt)) 1332 asbt += tc_tick_sbt; 1333 asbt += rsbt; 1334 } 1335 } else 1336 asbt = -1; 1337 seltdinit(td); 1338 /* Iterate until the timeout expires or descriptors become ready. */ 1339 for (;;) { 1340 error = pollscan(td, bits, nfds); 1341 if (error || td->td_retval[0] != 0) 1342 break; 1343 error = seltdwait(td, asbt, precision); 1344 if (error) 1345 break; 1346 error = pollrescan(td); 1347 if (error || td->td_retval[0] != 0) 1348 break; 1349 } 1350 seltdclear(td); 1351 1352 done: 1353 /* poll is not restarted after signals... */ 1354 if (error == ERESTART) 1355 error = EINTR; 1356 if (error == EWOULDBLOCK) 1357 error = 0; 1358 if (error == 0) { 1359 error = pollout(td, bits, uap->fds, nfds); 1360 if (error) 1361 goto out; 1362 } 1363 out: 1364 if (ni > sizeof(smallbits)) 1365 free(bits, M_TEMP); 1366 return (error); 1367 } 1368 1369 static int 1370 pollrescan(struct thread *td) 1371 { 1372 struct seltd *stp; 1373 struct selfd *sfp; 1374 struct selfd *sfn; 1375 struct selinfo *si; 1376 struct filedesc *fdp; 1377 struct file *fp; 1378 struct pollfd *fd; 1379 #ifdef CAPABILITIES 1380 cap_rights_t rights; 1381 #endif 1382 int n; 1383 1384 n = 0; 1385 fdp = td->td_proc->p_fd; 1386 stp = td->td_sel; 1387 FILEDESC_SLOCK(fdp); 1388 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1389 fd = (struct pollfd *)sfp->sf_cookie; 1390 si = sfp->sf_si; 1391 selfdfree(stp, sfp); 1392 /* If the selinfo wasn't cleared the event didn't fire. */ 1393 if (si != NULL) 1394 continue; 1395 fp = fdp->fd_ofiles[fd->fd].fde_file; 1396 #ifdef CAPABILITIES 1397 if (fp == NULL || 1398 cap_check(cap_rights(fdp, fd->fd), 1399 cap_rights_init(&rights, CAP_EVENT)) != 0) 1400 #else 1401 if (fp == NULL) 1402 #endif 1403 { 1404 fd->revents = POLLNVAL; 1405 n++; 1406 continue; 1407 } 1408 1409 /* 1410 * Note: backend also returns POLLHUP and 1411 * POLLERR if appropriate. 1412 */ 1413 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1414 if (fd->revents != 0) 1415 n++; 1416 } 1417 FILEDESC_SUNLOCK(fdp); 1418 stp->st_flags = 0; 1419 td->td_retval[0] = n; 1420 return (0); 1421 } 1422 1423 1424 static int 1425 pollout(td, fds, ufds, nfd) 1426 struct thread *td; 1427 struct pollfd *fds; 1428 struct pollfd *ufds; 1429 u_int nfd; 1430 { 1431 int error = 0; 1432 u_int i = 0; 1433 u_int n = 0; 1434 1435 for (i = 0; i < nfd; i++) { 1436 error = copyout(&fds->revents, &ufds->revents, 1437 sizeof(ufds->revents)); 1438 if (error) 1439 return (error); 1440 if (fds->revents != 0) 1441 n++; 1442 fds++; 1443 ufds++; 1444 } 1445 td->td_retval[0] = n; 1446 return (0); 1447 } 1448 1449 static int 1450 pollscan(td, fds, nfd) 1451 struct thread *td; 1452 struct pollfd *fds; 1453 u_int nfd; 1454 { 1455 struct filedesc *fdp = td->td_proc->p_fd; 1456 struct file *fp; 1457 #ifdef CAPABILITIES 1458 cap_rights_t rights; 1459 #endif 1460 int i, n = 0; 1461 1462 FILEDESC_SLOCK(fdp); 1463 for (i = 0; i < nfd; i++, fds++) { 1464 if (fds->fd > fdp->fd_lastfile) { 1465 fds->revents = POLLNVAL; 1466 n++; 1467 } else if (fds->fd < 0) { 1468 fds->revents = 0; 1469 } else { 1470 fp = fdp->fd_ofiles[fds->fd].fde_file; 1471 #ifdef CAPABILITIES 1472 if (fp == NULL || 1473 cap_check(cap_rights(fdp, fds->fd), 1474 cap_rights_init(&rights, CAP_EVENT)) != 0) 1475 #else 1476 if (fp == NULL) 1477 #endif 1478 { 1479 fds->revents = POLLNVAL; 1480 n++; 1481 } else { 1482 /* 1483 * Note: backend also returns POLLHUP and 1484 * POLLERR if appropriate. 1485 */ 1486 selfdalloc(td, fds); 1487 fds->revents = fo_poll(fp, fds->events, 1488 td->td_ucred, td); 1489 /* 1490 * POSIX requires POLLOUT to be never 1491 * set simultaneously with POLLHUP. 1492 */ 1493 if ((fds->revents & POLLHUP) != 0) 1494 fds->revents &= ~POLLOUT; 1495 1496 if (fds->revents != 0) 1497 n++; 1498 } 1499 } 1500 } 1501 FILEDESC_SUNLOCK(fdp); 1502 td->td_retval[0] = n; 1503 return (0); 1504 } 1505 1506 /* 1507 * OpenBSD poll system call. 1508 * 1509 * XXX this isn't quite a true representation.. OpenBSD uses select ops. 1510 */ 1511 #ifndef _SYS_SYSPROTO_H_ 1512 struct openbsd_poll_args { 1513 struct pollfd *fds; 1514 u_int nfds; 1515 int timeout; 1516 }; 1517 #endif 1518 int 1519 sys_openbsd_poll(td, uap) 1520 register struct thread *td; 1521 register struct openbsd_poll_args *uap; 1522 { 1523 return (sys_poll(td, (struct poll_args *)uap)); 1524 } 1525 1526 /* 1527 * XXX This was created specifically to support netncp and netsmb. This 1528 * allows the caller to specify a socket to wait for events on. It returns 1529 * 0 if any events matched and an error otherwise. There is no way to 1530 * determine which events fired. 1531 */ 1532 int 1533 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1534 { 1535 struct timeval rtv; 1536 sbintime_t asbt, precision, rsbt; 1537 int error; 1538 1539 precision = 0; /* stupid gcc! */ 1540 if (tvp != NULL) { 1541 rtv = *tvp; 1542 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1543 rtv.tv_usec >= 1000000) 1544 return (EINVAL); 1545 if (!timevalisset(&rtv)) 1546 asbt = 0; 1547 else if (rtv.tv_sec <= INT32_MAX) { 1548 rsbt = tvtosbt(rtv); 1549 precision = rsbt; 1550 precision >>= tc_precexp; 1551 if (TIMESEL(&asbt, rsbt)) 1552 asbt += tc_tick_sbt; 1553 if (asbt <= SBT_MAX - rsbt) 1554 asbt += rsbt; 1555 else 1556 asbt = -1; 1557 } else 1558 asbt = -1; 1559 } else 1560 asbt = -1; 1561 seltdinit(td); 1562 /* 1563 * Iterate until the timeout expires or the socket becomes ready. 1564 */ 1565 for (;;) { 1566 selfdalloc(td, NULL); 1567 error = sopoll(so, events, NULL, td); 1568 /* error here is actually the ready events. */ 1569 if (error) 1570 return (0); 1571 error = seltdwait(td, asbt, precision); 1572 if (error) 1573 break; 1574 } 1575 seltdclear(td); 1576 /* XXX Duplicates ncp/smb behavior. */ 1577 if (error == ERESTART) 1578 error = 0; 1579 return (error); 1580 } 1581 1582 /* 1583 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1584 * have two select sets, one for read and another for write. 1585 */ 1586 static void 1587 selfdalloc(struct thread *td, void *cookie) 1588 { 1589 struct seltd *stp; 1590 1591 stp = td->td_sel; 1592 if (stp->st_free1 == NULL) 1593 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1594 stp->st_free1->sf_td = stp; 1595 stp->st_free1->sf_cookie = cookie; 1596 if (stp->st_free2 == NULL) 1597 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1598 stp->st_free2->sf_td = stp; 1599 stp->st_free2->sf_cookie = cookie; 1600 } 1601 1602 static void 1603 selfdfree(struct seltd *stp, struct selfd *sfp) 1604 { 1605 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1606 if (sfp->sf_si != NULL) { 1607 mtx_lock(sfp->sf_mtx); 1608 if (sfp->sf_si != NULL) 1609 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1610 mtx_unlock(sfp->sf_mtx); 1611 } 1612 uma_zfree(selfd_zone, sfp); 1613 } 1614 1615 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1616 void 1617 seldrain(sip) 1618 struct selinfo *sip; 1619 { 1620 1621 /* 1622 * This feature is already provided by doselwakeup(), thus it is 1623 * enough to go for it. 1624 * Eventually, the context, should take care to avoid races 1625 * between thread calling select()/poll() and file descriptor 1626 * detaching, but, again, the races are just the same as 1627 * selwakeup(). 1628 */ 1629 doselwakeup(sip, -1); 1630 } 1631 1632 /* 1633 * Record a select request. 1634 */ 1635 void 1636 selrecord(selector, sip) 1637 struct thread *selector; 1638 struct selinfo *sip; 1639 { 1640 struct selfd *sfp; 1641 struct seltd *stp; 1642 struct mtx *mtxp; 1643 1644 stp = selector->td_sel; 1645 /* 1646 * Don't record when doing a rescan. 1647 */ 1648 if (stp->st_flags & SELTD_RESCAN) 1649 return; 1650 /* 1651 * Grab one of the preallocated descriptors. 1652 */ 1653 sfp = NULL; 1654 if ((sfp = stp->st_free1) != NULL) 1655 stp->st_free1 = NULL; 1656 else if ((sfp = stp->st_free2) != NULL) 1657 stp->st_free2 = NULL; 1658 else 1659 panic("selrecord: No free selfd on selq"); 1660 mtxp = sip->si_mtx; 1661 if (mtxp == NULL) 1662 mtxp = mtx_pool_find(mtxpool_select, sip); 1663 /* 1664 * Initialize the sfp and queue it in the thread. 1665 */ 1666 sfp->sf_si = sip; 1667 sfp->sf_mtx = mtxp; 1668 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1669 /* 1670 * Now that we've locked the sip, check for initialization. 1671 */ 1672 mtx_lock(mtxp); 1673 if (sip->si_mtx == NULL) { 1674 sip->si_mtx = mtxp; 1675 TAILQ_INIT(&sip->si_tdlist); 1676 } 1677 /* 1678 * Add this thread to the list of selfds listening on this selinfo. 1679 */ 1680 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1681 mtx_unlock(sip->si_mtx); 1682 } 1683 1684 /* Wake up a selecting thread. */ 1685 void 1686 selwakeup(sip) 1687 struct selinfo *sip; 1688 { 1689 doselwakeup(sip, -1); 1690 } 1691 1692 /* Wake up a selecting thread, and set its priority. */ 1693 void 1694 selwakeuppri(sip, pri) 1695 struct selinfo *sip; 1696 int pri; 1697 { 1698 doselwakeup(sip, pri); 1699 } 1700 1701 /* 1702 * Do a wakeup when a selectable event occurs. 1703 */ 1704 static void 1705 doselwakeup(sip, pri) 1706 struct selinfo *sip; 1707 int pri; 1708 { 1709 struct selfd *sfp; 1710 struct selfd *sfn; 1711 struct seltd *stp; 1712 1713 /* If it's not initialized there can't be any waiters. */ 1714 if (sip->si_mtx == NULL) 1715 return; 1716 /* 1717 * Locking the selinfo locks all selfds associated with it. 1718 */ 1719 mtx_lock(sip->si_mtx); 1720 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1721 /* 1722 * Once we remove this sfp from the list and clear the 1723 * sf_si seltdclear will know to ignore this si. 1724 */ 1725 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1726 sfp->sf_si = NULL; 1727 stp = sfp->sf_td; 1728 mtx_lock(&stp->st_mtx); 1729 stp->st_flags |= SELTD_PENDING; 1730 cv_broadcastpri(&stp->st_wait, pri); 1731 mtx_unlock(&stp->st_mtx); 1732 } 1733 mtx_unlock(sip->si_mtx); 1734 } 1735 1736 static void 1737 seltdinit(struct thread *td) 1738 { 1739 struct seltd *stp; 1740 1741 if ((stp = td->td_sel) != NULL) 1742 goto out; 1743 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1744 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1745 cv_init(&stp->st_wait, "select"); 1746 out: 1747 stp->st_flags = 0; 1748 STAILQ_INIT(&stp->st_selq); 1749 } 1750 1751 static int 1752 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1753 { 1754 struct seltd *stp; 1755 int error; 1756 1757 stp = td->td_sel; 1758 /* 1759 * An event of interest may occur while we do not hold the seltd 1760 * locked so check the pending flag before we sleep. 1761 */ 1762 mtx_lock(&stp->st_mtx); 1763 /* 1764 * Any further calls to selrecord will be a rescan. 1765 */ 1766 stp->st_flags |= SELTD_RESCAN; 1767 if (stp->st_flags & SELTD_PENDING) { 1768 mtx_unlock(&stp->st_mtx); 1769 return (0); 1770 } 1771 if (sbt == 0) 1772 error = EWOULDBLOCK; 1773 else if (sbt != -1) 1774 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 1775 sbt, precision, C_ABSOLUTE); 1776 else 1777 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1778 mtx_unlock(&stp->st_mtx); 1779 1780 return (error); 1781 } 1782 1783 void 1784 seltdfini(struct thread *td) 1785 { 1786 struct seltd *stp; 1787 1788 stp = td->td_sel; 1789 if (stp == NULL) 1790 return; 1791 if (stp->st_free1) 1792 uma_zfree(selfd_zone, stp->st_free1); 1793 if (stp->st_free2) 1794 uma_zfree(selfd_zone, stp->st_free2); 1795 td->td_sel = NULL; 1796 free(stp, M_SELECT); 1797 } 1798 1799 /* 1800 * Remove the references to the thread from all of the objects we were 1801 * polling. 1802 */ 1803 static void 1804 seltdclear(struct thread *td) 1805 { 1806 struct seltd *stp; 1807 struct selfd *sfp; 1808 struct selfd *sfn; 1809 1810 stp = td->td_sel; 1811 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1812 selfdfree(stp, sfp); 1813 stp->st_flags = 0; 1814 } 1815 1816 static void selectinit(void *); 1817 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1818 static void 1819 selectinit(void *dummy __unused) 1820 { 1821 1822 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, 1823 NULL, NULL, UMA_ALIGN_PTR, 0); 1824 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 1825 } 1826