1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/sysproto.h> 48 #include <sys/capsicum.h> 49 #include <sys/filedesc.h> 50 #include <sys/filio.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/lock.h> 54 #include <sys/proc.h> 55 #include <sys/signalvar.h> 56 #include <sys/socketvar.h> 57 #include <sys/uio.h> 58 #include <sys/kernel.h> 59 #include <sys/ktr.h> 60 #include <sys/limits.h> 61 #include <sys/malloc.h> 62 #include <sys/poll.h> 63 #include <sys/resourcevar.h> 64 #include <sys/selinfo.h> 65 #include <sys/sleepqueue.h> 66 #include <sys/syscallsubr.h> 67 #include <sys/sysctl.h> 68 #include <sys/sysent.h> 69 #include <sys/vnode.h> 70 #include <sys/bio.h> 71 #include <sys/buf.h> 72 #include <sys/condvar.h> 73 #ifdef KTRACE 74 #include <sys/ktrace.h> 75 #endif 76 77 #include <security/audit/audit.h> 78 79 /* 80 * The following macro defines how many bytes will be allocated from 81 * the stack instead of memory allocated when passing the IOCTL data 82 * structures from userspace and to the kernel. Some IOCTLs having 83 * small data structures are used very frequently and this small 84 * buffer on the stack gives a significant speedup improvement for 85 * those requests. The value of this define should be greater or equal 86 * to 64 bytes and should also be power of two. The data structure is 87 * currently hard-aligned to a 8-byte boundary on the stack. This 88 * should currently be sufficient for all supported platforms. 89 */ 90 #define SYS_IOCTL_SMALL_SIZE 128 /* bytes */ 91 #define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */ 92 93 #ifdef __LP64__ 94 static int iosize_max_clamp = 0; 95 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, 96 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); 97 static int devfs_iosize_max_clamp = 1; 98 SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW, 99 &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices"); 100 #endif 101 102 /* 103 * Assert that the return value of read(2) and write(2) syscalls fits 104 * into a register. If not, an architecture will need to provide the 105 * usermode wrappers to reconstruct the result. 106 */ 107 CTASSERT(sizeof(register_t) >= sizeof(size_t)); 108 109 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 110 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); 111 MALLOC_DEFINE(M_IOV, "iov", "large iov's"); 112 113 static int pollout(struct thread *, struct pollfd *, struct pollfd *, 114 u_int); 115 static int pollscan(struct thread *, struct pollfd *, u_int); 116 static int pollrescan(struct thread *); 117 static int selscan(struct thread *, fd_mask **, fd_mask **, int); 118 static int selrescan(struct thread *, fd_mask **, fd_mask **); 119 static void selfdalloc(struct thread *, void *); 120 static void selfdfree(struct seltd *, struct selfd *); 121 static int dofileread(struct thread *, int, struct file *, struct uio *, 122 off_t, int); 123 static int dofilewrite(struct thread *, int, struct file *, struct uio *, 124 off_t, int); 125 static void doselwakeup(struct selinfo *, int); 126 static void seltdinit(struct thread *); 127 static int seltdwait(struct thread *, sbintime_t, sbintime_t); 128 static void seltdclear(struct thread *); 129 130 /* 131 * One seltd per-thread allocated on demand as needed. 132 * 133 * t - protected by st_mtx 134 * k - Only accessed by curthread or read-only 135 */ 136 struct seltd { 137 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ 138 struct selfd *st_free1; /* (k) free fd for read set. */ 139 struct selfd *st_free2; /* (k) free fd for write set. */ 140 struct mtx st_mtx; /* Protects struct seltd */ 141 struct cv st_wait; /* (t) Wait channel. */ 142 int st_flags; /* (t) SELTD_ flags. */ 143 }; 144 145 #define SELTD_PENDING 0x0001 /* We have pending events. */ 146 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */ 147 148 /* 149 * One selfd allocated per-thread per-file-descriptor. 150 * f - protected by sf_mtx 151 */ 152 struct selfd { 153 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ 154 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ 155 struct selinfo *sf_si; /* (f) selinfo when linked. */ 156 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ 157 struct seltd *sf_td; /* (k) owning seltd. */ 158 void *sf_cookie; /* (k) fd or pollfd. */ 159 u_int sf_refs; 160 }; 161 162 static uma_zone_t selfd_zone; 163 static struct mtx_pool *mtxpool_select; 164 165 #ifdef __LP64__ 166 size_t 167 devfs_iosize_max(void) 168 { 169 170 return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 171 INT_MAX : SSIZE_MAX); 172 } 173 174 size_t 175 iosize_max(void) 176 { 177 178 return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 179 INT_MAX : SSIZE_MAX); 180 } 181 #endif 182 183 #ifndef _SYS_SYSPROTO_H_ 184 struct read_args { 185 int fd; 186 void *buf; 187 size_t nbyte; 188 }; 189 #endif 190 int 191 sys_read(td, uap) 192 struct thread *td; 193 struct read_args *uap; 194 { 195 struct uio auio; 196 struct iovec aiov; 197 int error; 198 199 if (uap->nbyte > IOSIZE_MAX) 200 return (EINVAL); 201 aiov.iov_base = uap->buf; 202 aiov.iov_len = uap->nbyte; 203 auio.uio_iov = &aiov; 204 auio.uio_iovcnt = 1; 205 auio.uio_resid = uap->nbyte; 206 auio.uio_segflg = UIO_USERSPACE; 207 error = kern_readv(td, uap->fd, &auio); 208 return (error); 209 } 210 211 /* 212 * Positioned read system call 213 */ 214 #ifndef _SYS_SYSPROTO_H_ 215 struct pread_args { 216 int fd; 217 void *buf; 218 size_t nbyte; 219 int pad; 220 off_t offset; 221 }; 222 #endif 223 int 224 sys_pread(struct thread *td, struct pread_args *uap) 225 { 226 227 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 228 } 229 230 int 231 kern_pread(struct thread *td, int fd, void *buf, size_t nbyte, off_t offset) 232 { 233 struct uio auio; 234 struct iovec aiov; 235 int error; 236 237 if (nbyte > IOSIZE_MAX) 238 return (EINVAL); 239 aiov.iov_base = buf; 240 aiov.iov_len = nbyte; 241 auio.uio_iov = &aiov; 242 auio.uio_iovcnt = 1; 243 auio.uio_resid = nbyte; 244 auio.uio_segflg = UIO_USERSPACE; 245 error = kern_preadv(td, fd, &auio, offset); 246 return (error); 247 } 248 249 #if defined(COMPAT_FREEBSD6) 250 int 251 freebsd6_pread(struct thread *td, struct freebsd6_pread_args *uap) 252 { 253 254 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 255 } 256 #endif 257 258 /* 259 * Scatter read system call. 260 */ 261 #ifndef _SYS_SYSPROTO_H_ 262 struct readv_args { 263 int fd; 264 struct iovec *iovp; 265 u_int iovcnt; 266 }; 267 #endif 268 int 269 sys_readv(struct thread *td, struct readv_args *uap) 270 { 271 struct uio *auio; 272 int error; 273 274 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 275 if (error) 276 return (error); 277 error = kern_readv(td, uap->fd, auio); 278 free(auio, M_IOV); 279 return (error); 280 } 281 282 int 283 kern_readv(struct thread *td, int fd, struct uio *auio) 284 { 285 struct file *fp; 286 cap_rights_t rights; 287 int error; 288 289 error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp); 290 if (error) 291 return (error); 292 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 293 fdrop(fp, td); 294 return (error); 295 } 296 297 /* 298 * Scatter positioned read system call. 299 */ 300 #ifndef _SYS_SYSPROTO_H_ 301 struct preadv_args { 302 int fd; 303 struct iovec *iovp; 304 u_int iovcnt; 305 off_t offset; 306 }; 307 #endif 308 int 309 sys_preadv(struct thread *td, struct preadv_args *uap) 310 { 311 struct uio *auio; 312 int error; 313 314 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 315 if (error) 316 return (error); 317 error = kern_preadv(td, uap->fd, auio, uap->offset); 318 free(auio, M_IOV); 319 return (error); 320 } 321 322 int 323 kern_preadv(td, fd, auio, offset) 324 struct thread *td; 325 int fd; 326 struct uio *auio; 327 off_t offset; 328 { 329 struct file *fp; 330 cap_rights_t rights; 331 int error; 332 333 error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp); 334 if (error) 335 return (error); 336 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 337 error = ESPIPE; 338 else if (offset < 0 && 339 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 340 error = EINVAL; 341 else 342 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 343 fdrop(fp, td); 344 return (error); 345 } 346 347 /* 348 * Common code for readv and preadv that reads data in 349 * from a file using the passed in uio, offset, and flags. 350 */ 351 static int 352 dofileread(td, fd, fp, auio, offset, flags) 353 struct thread *td; 354 int fd; 355 struct file *fp; 356 struct uio *auio; 357 off_t offset; 358 int flags; 359 { 360 ssize_t cnt; 361 int error; 362 #ifdef KTRACE 363 struct uio *ktruio = NULL; 364 #endif 365 366 AUDIT_ARG_FD(fd); 367 368 /* Finish zero length reads right here */ 369 if (auio->uio_resid == 0) { 370 td->td_retval[0] = 0; 371 return (0); 372 } 373 auio->uio_rw = UIO_READ; 374 auio->uio_offset = offset; 375 auio->uio_td = td; 376 #ifdef KTRACE 377 if (KTRPOINT(td, KTR_GENIO)) 378 ktruio = cloneuio(auio); 379 #endif 380 cnt = auio->uio_resid; 381 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 382 if (auio->uio_resid != cnt && (error == ERESTART || 383 error == EINTR || error == EWOULDBLOCK)) 384 error = 0; 385 } 386 cnt -= auio->uio_resid; 387 #ifdef KTRACE 388 if (ktruio != NULL) { 389 ktruio->uio_resid = cnt; 390 ktrgenio(fd, UIO_READ, ktruio, error); 391 } 392 #endif 393 td->td_retval[0] = cnt; 394 return (error); 395 } 396 397 #ifndef _SYS_SYSPROTO_H_ 398 struct write_args { 399 int fd; 400 const void *buf; 401 size_t nbyte; 402 }; 403 #endif 404 int 405 sys_write(td, uap) 406 struct thread *td; 407 struct write_args *uap; 408 { 409 struct uio auio; 410 struct iovec aiov; 411 int error; 412 413 if (uap->nbyte > IOSIZE_MAX) 414 return (EINVAL); 415 aiov.iov_base = (void *)(uintptr_t)uap->buf; 416 aiov.iov_len = uap->nbyte; 417 auio.uio_iov = &aiov; 418 auio.uio_iovcnt = 1; 419 auio.uio_resid = uap->nbyte; 420 auio.uio_segflg = UIO_USERSPACE; 421 error = kern_writev(td, uap->fd, &auio); 422 return (error); 423 } 424 425 /* 426 * Positioned write system call. 427 */ 428 #ifndef _SYS_SYSPROTO_H_ 429 struct pwrite_args { 430 int fd; 431 const void *buf; 432 size_t nbyte; 433 int pad; 434 off_t offset; 435 }; 436 #endif 437 int 438 sys_pwrite(struct thread *td, struct pwrite_args *uap) 439 { 440 441 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 442 } 443 444 int 445 kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte, 446 off_t offset) 447 { 448 struct uio auio; 449 struct iovec aiov; 450 int error; 451 452 if (nbyte > IOSIZE_MAX) 453 return (EINVAL); 454 aiov.iov_base = (void *)(uintptr_t)buf; 455 aiov.iov_len = nbyte; 456 auio.uio_iov = &aiov; 457 auio.uio_iovcnt = 1; 458 auio.uio_resid = nbyte; 459 auio.uio_segflg = UIO_USERSPACE; 460 error = kern_pwritev(td, fd, &auio, offset); 461 return (error); 462 } 463 464 #if defined(COMPAT_FREEBSD6) 465 int 466 freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap) 467 { 468 469 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 470 } 471 #endif 472 473 /* 474 * Gather write system call. 475 */ 476 #ifndef _SYS_SYSPROTO_H_ 477 struct writev_args { 478 int fd; 479 struct iovec *iovp; 480 u_int iovcnt; 481 }; 482 #endif 483 int 484 sys_writev(struct thread *td, struct writev_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_writev(td, uap->fd, auio); 493 free(auio, M_IOV); 494 return (error); 495 } 496 497 int 498 kern_writev(struct thread *td, int fd, struct uio *auio) 499 { 500 struct file *fp; 501 cap_rights_t rights; 502 int error; 503 504 error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp); 505 if (error) 506 return (error); 507 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 508 fdrop(fp, td); 509 return (error); 510 } 511 512 /* 513 * Gather positioned write system call. 514 */ 515 #ifndef _SYS_SYSPROTO_H_ 516 struct pwritev_args { 517 int fd; 518 struct iovec *iovp; 519 u_int iovcnt; 520 off_t offset; 521 }; 522 #endif 523 int 524 sys_pwritev(struct thread *td, struct pwritev_args *uap) 525 { 526 struct uio *auio; 527 int error; 528 529 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 530 if (error) 531 return (error); 532 error = kern_pwritev(td, uap->fd, auio, uap->offset); 533 free(auio, M_IOV); 534 return (error); 535 } 536 537 int 538 kern_pwritev(td, fd, auio, offset) 539 struct thread *td; 540 struct uio *auio; 541 int fd; 542 off_t offset; 543 { 544 struct file *fp; 545 cap_rights_t rights; 546 int error; 547 548 error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp); 549 if (error) 550 return (error); 551 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 552 error = ESPIPE; 553 else if (offset < 0 && 554 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 555 error = EINVAL; 556 else 557 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 558 fdrop(fp, td); 559 return (error); 560 } 561 562 /* 563 * Common code for writev and pwritev that writes data to 564 * a file using the passed in uio, offset, and flags. 565 */ 566 static int 567 dofilewrite(td, fd, fp, auio, offset, flags) 568 struct thread *td; 569 int fd; 570 struct file *fp; 571 struct uio *auio; 572 off_t offset; 573 int flags; 574 { 575 ssize_t cnt; 576 int error; 577 #ifdef KTRACE 578 struct uio *ktruio = NULL; 579 #endif 580 581 AUDIT_ARG_FD(fd); 582 auio->uio_rw = UIO_WRITE; 583 auio->uio_td = td; 584 auio->uio_offset = offset; 585 #ifdef KTRACE 586 if (KTRPOINT(td, KTR_GENIO)) 587 ktruio = cloneuio(auio); 588 #endif 589 cnt = auio->uio_resid; 590 if (fp->f_type == DTYPE_VNODE && 591 (fp->f_vnread_flags & FDEVFS_VNODE) == 0) 592 bwillwrite(); 593 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 594 if (auio->uio_resid != cnt && (error == ERESTART || 595 error == EINTR || error == EWOULDBLOCK)) 596 error = 0; 597 /* Socket layer is responsible for issuing SIGPIPE. */ 598 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 599 PROC_LOCK(td->td_proc); 600 tdsignal(td, SIGPIPE); 601 PROC_UNLOCK(td->td_proc); 602 } 603 } 604 cnt -= auio->uio_resid; 605 #ifdef KTRACE 606 if (ktruio != NULL) { 607 ktruio->uio_resid = cnt; 608 ktrgenio(fd, UIO_WRITE, ktruio, error); 609 } 610 #endif 611 td->td_retval[0] = cnt; 612 return (error); 613 } 614 615 /* 616 * Truncate a file given a file descriptor. 617 * 618 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 619 * descriptor isn't writable. 620 */ 621 int 622 kern_ftruncate(td, fd, length) 623 struct thread *td; 624 int fd; 625 off_t length; 626 { 627 struct file *fp; 628 cap_rights_t rights; 629 int error; 630 631 AUDIT_ARG_FD(fd); 632 if (length < 0) 633 return (EINVAL); 634 error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp); 635 if (error) 636 return (error); 637 AUDIT_ARG_FILE(td->td_proc, fp); 638 if (!(fp->f_flag & FWRITE)) { 639 fdrop(fp, td); 640 return (EINVAL); 641 } 642 error = fo_truncate(fp, length, td->td_ucred, td); 643 fdrop(fp, td); 644 return (error); 645 } 646 647 #ifndef _SYS_SYSPROTO_H_ 648 struct ftruncate_args { 649 int fd; 650 int pad; 651 off_t length; 652 }; 653 #endif 654 int 655 sys_ftruncate(td, uap) 656 struct thread *td; 657 struct ftruncate_args *uap; 658 { 659 660 return (kern_ftruncate(td, uap->fd, uap->length)); 661 } 662 663 #if defined(COMPAT_43) 664 #ifndef _SYS_SYSPROTO_H_ 665 struct oftruncate_args { 666 int fd; 667 long length; 668 }; 669 #endif 670 int 671 oftruncate(td, uap) 672 struct thread *td; 673 struct oftruncate_args *uap; 674 { 675 676 return (kern_ftruncate(td, uap->fd, uap->length)); 677 } 678 #endif /* COMPAT_43 */ 679 680 #ifndef _SYS_SYSPROTO_H_ 681 struct ioctl_args { 682 int fd; 683 u_long com; 684 caddr_t data; 685 }; 686 #endif 687 /* ARGSUSED */ 688 int 689 sys_ioctl(struct thread *td, struct ioctl_args *uap) 690 { 691 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); 692 u_long com; 693 int arg, error; 694 u_int size; 695 caddr_t data; 696 697 if (uap->com > 0xffffffff) { 698 printf( 699 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 700 td->td_proc->p_pid, td->td_name, uap->com); 701 uap->com &= 0xffffffff; 702 } 703 com = uap->com; 704 705 /* 706 * Interpret high order word to find amount of data to be 707 * copied to/from the user's address space. 708 */ 709 size = IOCPARM_LEN(com); 710 if ((size > IOCPARM_MAX) || 711 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 712 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 713 ((com & IOC_OUT) && size == 0) || 714 #else 715 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 716 #endif 717 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 718 return (ENOTTY); 719 720 if (size > 0) { 721 if (com & IOC_VOID) { 722 /* Integer argument. */ 723 arg = (intptr_t)uap->data; 724 data = (void *)&arg; 725 size = 0; 726 } else { 727 if (size > SYS_IOCTL_SMALL_SIZE) 728 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 729 else 730 data = smalldata; 731 } 732 } else 733 data = (void *)&uap->data; 734 if (com & IOC_IN) { 735 error = copyin(uap->data, data, (u_int)size); 736 if (error != 0) 737 goto out; 738 } else if (com & IOC_OUT) { 739 /* 740 * Zero the buffer so the user always 741 * gets back something deterministic. 742 */ 743 bzero(data, size); 744 } 745 746 error = kern_ioctl(td, uap->fd, com, data); 747 748 if (error == 0 && (com & IOC_OUT)) 749 error = copyout(data, uap->data, (u_int)size); 750 751 out: 752 if (size > SYS_IOCTL_SMALL_SIZE) 753 free(data, M_IOCTLOPS); 754 return (error); 755 } 756 757 int 758 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 759 { 760 struct file *fp; 761 struct filedesc *fdp; 762 #ifndef CAPABILITIES 763 cap_rights_t rights; 764 #endif 765 int error, tmp, locked; 766 767 AUDIT_ARG_FD(fd); 768 AUDIT_ARG_CMD(com); 769 770 fdp = td->td_proc->p_fd; 771 772 switch (com) { 773 case FIONCLEX: 774 case FIOCLEX: 775 FILEDESC_XLOCK(fdp); 776 locked = LA_XLOCKED; 777 break; 778 default: 779 #ifdef CAPABILITIES 780 FILEDESC_SLOCK(fdp); 781 locked = LA_SLOCKED; 782 #else 783 locked = LA_UNLOCKED; 784 #endif 785 break; 786 } 787 788 #ifdef CAPABILITIES 789 if ((fp = fget_locked(fdp, fd)) == NULL) { 790 error = EBADF; 791 goto out; 792 } 793 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 794 fp = NULL; /* fhold() was not called yet */ 795 goto out; 796 } 797 fhold(fp); 798 if (locked == LA_SLOCKED) { 799 FILEDESC_SUNLOCK(fdp); 800 locked = LA_UNLOCKED; 801 } 802 #else 803 error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp); 804 if (error != 0) { 805 fp = NULL; 806 goto out; 807 } 808 #endif 809 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 810 error = EBADF; 811 goto out; 812 } 813 814 switch (com) { 815 case FIONCLEX: 816 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 817 goto out; 818 case FIOCLEX: 819 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 820 goto out; 821 case FIONBIO: 822 if ((tmp = *(int *)data)) 823 atomic_set_int(&fp->f_flag, FNONBLOCK); 824 else 825 atomic_clear_int(&fp->f_flag, FNONBLOCK); 826 data = (void *)&tmp; 827 break; 828 case FIOASYNC: 829 if ((tmp = *(int *)data)) 830 atomic_set_int(&fp->f_flag, FASYNC); 831 else 832 atomic_clear_int(&fp->f_flag, FASYNC); 833 data = (void *)&tmp; 834 break; 835 } 836 837 error = fo_ioctl(fp, com, data, td->td_ucred, td); 838 out: 839 switch (locked) { 840 case LA_XLOCKED: 841 FILEDESC_XUNLOCK(fdp); 842 break; 843 #ifdef CAPABILITIES 844 case LA_SLOCKED: 845 FILEDESC_SUNLOCK(fdp); 846 break; 847 #endif 848 default: 849 FILEDESC_UNLOCK_ASSERT(fdp); 850 break; 851 } 852 if (fp != NULL) 853 fdrop(fp, td); 854 return (error); 855 } 856 857 int 858 poll_no_poll(int events) 859 { 860 /* 861 * Return true for read/write. If the user asked for something 862 * special, return POLLNVAL, so that clients have a way of 863 * determining reliably whether or not the extended 864 * functionality is present without hard-coding knowledge 865 * of specific filesystem implementations. 866 */ 867 if (events & ~POLLSTANDARD) 868 return (POLLNVAL); 869 870 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 871 } 872 873 int 874 sys_pselect(struct thread *td, struct pselect_args *uap) 875 { 876 struct timespec ts; 877 struct timeval tv, *tvp; 878 sigset_t set, *uset; 879 int error; 880 881 if (uap->ts != NULL) { 882 error = copyin(uap->ts, &ts, sizeof(ts)); 883 if (error != 0) 884 return (error); 885 TIMESPEC_TO_TIMEVAL(&tv, &ts); 886 tvp = &tv; 887 } else 888 tvp = NULL; 889 if (uap->sm != NULL) { 890 error = copyin(uap->sm, &set, sizeof(set)); 891 if (error != 0) 892 return (error); 893 uset = &set; 894 } else 895 uset = NULL; 896 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 897 uset, NFDBITS)); 898 } 899 900 int 901 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 902 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 903 { 904 int error; 905 906 if (uset != NULL) { 907 error = kern_sigprocmask(td, SIG_SETMASK, uset, 908 &td->td_oldsigmask, 0); 909 if (error != 0) 910 return (error); 911 td->td_pflags |= TDP_OLDMASK; 912 /* 913 * Make sure that ast() is called on return to 914 * usermode and TDP_OLDMASK is cleared, restoring old 915 * sigmask. 916 */ 917 thread_lock(td); 918 td->td_flags |= TDF_ASTPENDING; 919 thread_unlock(td); 920 } 921 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 922 return (error); 923 } 924 925 #ifndef _SYS_SYSPROTO_H_ 926 struct select_args { 927 int nd; 928 fd_set *in, *ou, *ex; 929 struct timeval *tv; 930 }; 931 #endif 932 int 933 sys_select(struct thread *td, struct select_args *uap) 934 { 935 struct timeval tv, *tvp; 936 int error; 937 938 if (uap->tv != NULL) { 939 error = copyin(uap->tv, &tv, sizeof(tv)); 940 if (error) 941 return (error); 942 tvp = &tv; 943 } else 944 tvp = NULL; 945 946 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 947 NFDBITS)); 948 } 949 950 /* 951 * In the unlikely case when user specified n greater then the last 952 * open file descriptor, check that no bits are set after the last 953 * valid fd. We must return EBADF if any is set. 954 * 955 * There are applications that rely on the behaviour. 956 * 957 * nd is fd_lastfile + 1. 958 */ 959 static int 960 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 961 { 962 char *addr, *oaddr; 963 int b, i, res; 964 uint8_t bits; 965 966 if (nd >= ndu || fd_in == NULL) 967 return (0); 968 969 oaddr = NULL; 970 bits = 0; /* silence gcc */ 971 for (i = nd; i < ndu; i++) { 972 b = i / NBBY; 973 #if BYTE_ORDER == LITTLE_ENDIAN 974 addr = (char *)fd_in + b; 975 #else 976 addr = (char *)fd_in; 977 if (abi_nfdbits == NFDBITS) { 978 addr += rounddown(b, sizeof(fd_mask)) + 979 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 980 } else { 981 addr += rounddown(b, sizeof(uint32_t)) + 982 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 983 } 984 #endif 985 if (addr != oaddr) { 986 res = fubyte(addr); 987 if (res == -1) 988 return (EFAULT); 989 oaddr = addr; 990 bits = res; 991 } 992 if ((bits & (1 << (i % NBBY))) != 0) 993 return (EBADF); 994 } 995 return (0); 996 } 997 998 int 999 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 1000 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 1001 { 1002 struct filedesc *fdp; 1003 /* 1004 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 1005 * infds with the new FD_SETSIZE of 1024, and more than enough for 1006 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 1007 * of 256. 1008 */ 1009 fd_mask s_selbits[howmany(2048, NFDBITS)]; 1010 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 1011 struct timeval rtv; 1012 sbintime_t asbt, precision, rsbt; 1013 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 1014 int error, lf, ndu; 1015 1016 if (nd < 0) 1017 return (EINVAL); 1018 fdp = td->td_proc->p_fd; 1019 ndu = nd; 1020 lf = fdp->fd_lastfile; 1021 if (nd > lf + 1) 1022 nd = lf + 1; 1023 1024 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 1025 if (error != 0) 1026 return (error); 1027 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 1028 if (error != 0) 1029 return (error); 1030 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 1031 if (error != 0) 1032 return (error); 1033 1034 /* 1035 * Allocate just enough bits for the non-null fd_sets. Use the 1036 * preallocated auto buffer if possible. 1037 */ 1038 nfdbits = roundup(nd, NFDBITS); 1039 ncpbytes = nfdbits / NBBY; 1040 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 1041 nbufbytes = 0; 1042 if (fd_in != NULL) 1043 nbufbytes += 2 * ncpbytes; 1044 if (fd_ou != NULL) 1045 nbufbytes += 2 * ncpbytes; 1046 if (fd_ex != NULL) 1047 nbufbytes += 2 * ncpbytes; 1048 if (nbufbytes <= sizeof s_selbits) 1049 selbits = &s_selbits[0]; 1050 else 1051 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1052 1053 /* 1054 * Assign pointers into the bit buffers and fetch the input bits. 1055 * Put the output buffers together so that they can be bzeroed 1056 * together. 1057 */ 1058 sbp = selbits; 1059 #define getbits(name, x) \ 1060 do { \ 1061 if (name == NULL) { \ 1062 ibits[x] = NULL; \ 1063 obits[x] = NULL; \ 1064 } else { \ 1065 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1066 obits[x] = sbp; \ 1067 sbp += ncpbytes / sizeof *sbp; \ 1068 error = copyin(name, ibits[x], ncpubytes); \ 1069 if (error != 0) \ 1070 goto done; \ 1071 bzero((char *)ibits[x] + ncpubytes, \ 1072 ncpbytes - ncpubytes); \ 1073 } \ 1074 } while (0) 1075 getbits(fd_in, 0); 1076 getbits(fd_ou, 1); 1077 getbits(fd_ex, 2); 1078 #undef getbits 1079 1080 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1081 /* 1082 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1083 * we are running under 32-bit emulation. This should be more 1084 * generic. 1085 */ 1086 #define swizzle_fdset(bits) \ 1087 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1088 int i; \ 1089 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1090 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1091 } 1092 #else 1093 #define swizzle_fdset(bits) 1094 #endif 1095 1096 /* Make sure the bit order makes it through an ABI transition */ 1097 swizzle_fdset(ibits[0]); 1098 swizzle_fdset(ibits[1]); 1099 swizzle_fdset(ibits[2]); 1100 1101 if (nbufbytes != 0) 1102 bzero(selbits, nbufbytes / 2); 1103 1104 precision = 0; 1105 if (tvp != NULL) { 1106 rtv = *tvp; 1107 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1108 rtv.tv_usec >= 1000000) { 1109 error = EINVAL; 1110 goto done; 1111 } 1112 if (!timevalisset(&rtv)) 1113 asbt = 0; 1114 else if (rtv.tv_sec <= INT32_MAX) { 1115 rsbt = tvtosbt(rtv); 1116 precision = rsbt; 1117 precision >>= tc_precexp; 1118 if (TIMESEL(&asbt, rsbt)) 1119 asbt += tc_tick_sbt; 1120 if (asbt <= SBT_MAX - rsbt) 1121 asbt += rsbt; 1122 else 1123 asbt = -1; 1124 } else 1125 asbt = -1; 1126 } else 1127 asbt = -1; 1128 seltdinit(td); 1129 /* Iterate until the timeout expires or descriptors become ready. */ 1130 for (;;) { 1131 error = selscan(td, ibits, obits, nd); 1132 if (error || td->td_retval[0] != 0) 1133 break; 1134 error = seltdwait(td, asbt, precision); 1135 if (error) 1136 break; 1137 error = selrescan(td, ibits, obits); 1138 if (error || td->td_retval[0] != 0) 1139 break; 1140 } 1141 seltdclear(td); 1142 1143 done: 1144 /* select is not restarted after signals... */ 1145 if (error == ERESTART) 1146 error = EINTR; 1147 if (error == EWOULDBLOCK) 1148 error = 0; 1149 1150 /* swizzle bit order back, if necessary */ 1151 swizzle_fdset(obits[0]); 1152 swizzle_fdset(obits[1]); 1153 swizzle_fdset(obits[2]); 1154 #undef swizzle_fdset 1155 1156 #define putbits(name, x) \ 1157 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1158 error = error2; 1159 if (error == 0) { 1160 int error2; 1161 1162 putbits(fd_in, 0); 1163 putbits(fd_ou, 1); 1164 putbits(fd_ex, 2); 1165 #undef putbits 1166 } 1167 if (selbits != &s_selbits[0]) 1168 free(selbits, M_SELECT); 1169 1170 return (error); 1171 } 1172 /* 1173 * Convert a select bit set to poll flags. 1174 * 1175 * The backend always returns POLLHUP/POLLERR if appropriate and we 1176 * return this as a set bit in any set. 1177 */ 1178 static int select_flags[3] = { 1179 POLLRDNORM | POLLHUP | POLLERR, 1180 POLLWRNORM | POLLHUP | POLLERR, 1181 POLLRDBAND | POLLERR 1182 }; 1183 1184 /* 1185 * Compute the fo_poll flags required for a fd given by the index and 1186 * bit position in the fd_mask array. 1187 */ 1188 static __inline int 1189 selflags(fd_mask **ibits, int idx, fd_mask bit) 1190 { 1191 int flags; 1192 int msk; 1193 1194 flags = 0; 1195 for (msk = 0; msk < 3; msk++) { 1196 if (ibits[msk] == NULL) 1197 continue; 1198 if ((ibits[msk][idx] & bit) == 0) 1199 continue; 1200 flags |= select_flags[msk]; 1201 } 1202 return (flags); 1203 } 1204 1205 /* 1206 * Set the appropriate output bits given a mask of fired events and the 1207 * input bits originally requested. 1208 */ 1209 static __inline int 1210 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1211 { 1212 int msk; 1213 int n; 1214 1215 n = 0; 1216 for (msk = 0; msk < 3; msk++) { 1217 if ((events & select_flags[msk]) == 0) 1218 continue; 1219 if (ibits[msk] == NULL) 1220 continue; 1221 if ((ibits[msk][idx] & bit) == 0) 1222 continue; 1223 /* 1224 * XXX Check for a duplicate set. This can occur because a 1225 * socket calls selrecord() twice for each poll() call 1226 * resulting in two selfds per real fd. selrescan() will 1227 * call selsetbits twice as a result. 1228 */ 1229 if ((obits[msk][idx] & bit) != 0) 1230 continue; 1231 obits[msk][idx] |= bit; 1232 n++; 1233 } 1234 1235 return (n); 1236 } 1237 1238 static __inline int 1239 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) 1240 { 1241 cap_rights_t rights; 1242 1243 cap_rights_init(&rights, CAP_EVENT); 1244 1245 return (fget_unlocked(fdp, fd, &rights, fpp, NULL)); 1246 } 1247 1248 /* 1249 * Traverse the list of fds attached to this thread's seltd and check for 1250 * completion. 1251 */ 1252 static int 1253 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1254 { 1255 struct filedesc *fdp; 1256 struct selinfo *si; 1257 struct seltd *stp; 1258 struct selfd *sfp; 1259 struct selfd *sfn; 1260 struct file *fp; 1261 fd_mask bit; 1262 int fd, ev, n, idx; 1263 int error; 1264 1265 fdp = td->td_proc->p_fd; 1266 stp = td->td_sel; 1267 n = 0; 1268 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1269 fd = (int)(uintptr_t)sfp->sf_cookie; 1270 si = sfp->sf_si; 1271 selfdfree(stp, sfp); 1272 /* If the selinfo wasn't cleared the event didn't fire. */ 1273 if (si != NULL) 1274 continue; 1275 error = getselfd_cap(fdp, fd, &fp); 1276 if (error) 1277 return (error); 1278 idx = fd / NFDBITS; 1279 bit = (fd_mask)1 << (fd % NFDBITS); 1280 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1281 fdrop(fp, td); 1282 if (ev != 0) 1283 n += selsetbits(ibits, obits, idx, bit, ev); 1284 } 1285 stp->st_flags = 0; 1286 td->td_retval[0] = n; 1287 return (0); 1288 } 1289 1290 /* 1291 * Perform the initial filedescriptor scan and register ourselves with 1292 * each selinfo. 1293 */ 1294 static int 1295 selscan(td, ibits, obits, nfd) 1296 struct thread *td; 1297 fd_mask **ibits, **obits; 1298 int nfd; 1299 { 1300 struct filedesc *fdp; 1301 struct file *fp; 1302 fd_mask bit; 1303 int ev, flags, end, fd; 1304 int n, idx; 1305 int error; 1306 1307 fdp = td->td_proc->p_fd; 1308 n = 0; 1309 for (idx = 0, fd = 0; fd < nfd; idx++) { 1310 end = imin(fd + NFDBITS, nfd); 1311 for (bit = 1; fd < end; bit <<= 1, fd++) { 1312 /* Compute the list of events we're interested in. */ 1313 flags = selflags(ibits, idx, bit); 1314 if (flags == 0) 1315 continue; 1316 error = getselfd_cap(fdp, fd, &fp); 1317 if (error) 1318 return (error); 1319 selfdalloc(td, (void *)(uintptr_t)fd); 1320 ev = fo_poll(fp, flags, td->td_ucred, td); 1321 fdrop(fp, td); 1322 if (ev != 0) 1323 n += selsetbits(ibits, obits, idx, bit, ev); 1324 } 1325 } 1326 1327 td->td_retval[0] = n; 1328 return (0); 1329 } 1330 1331 int 1332 sys_poll(struct thread *td, struct poll_args *uap) 1333 { 1334 struct timespec ts, *tsp; 1335 1336 if (uap->timeout != INFTIM) { 1337 if (uap->timeout < 0) 1338 return (EINVAL); 1339 ts.tv_sec = uap->timeout / 1000; 1340 ts.tv_nsec = (uap->timeout % 1000) * 1000000; 1341 tsp = &ts; 1342 } else 1343 tsp = NULL; 1344 1345 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); 1346 } 1347 1348 int 1349 kern_poll(struct thread *td, struct pollfd *fds, u_int nfds, 1350 struct timespec *tsp, sigset_t *uset) 1351 { 1352 struct pollfd *bits; 1353 struct pollfd smallbits[32]; 1354 sbintime_t sbt, precision, tmp; 1355 time_t over; 1356 struct timespec ts; 1357 int error; 1358 size_t ni; 1359 1360 precision = 0; 1361 if (tsp != NULL) { 1362 if (tsp->tv_sec < 0) 1363 return (EINVAL); 1364 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000) 1365 return (EINVAL); 1366 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1367 sbt = 0; 1368 else { 1369 ts = *tsp; 1370 if (ts.tv_sec > INT32_MAX / 2) { 1371 over = ts.tv_sec - INT32_MAX / 2; 1372 ts.tv_sec -= over; 1373 } else 1374 over = 0; 1375 tmp = tstosbt(ts); 1376 precision = tmp; 1377 precision >>= tc_precexp; 1378 if (TIMESEL(&sbt, tmp)) 1379 sbt += tc_tick_sbt; 1380 sbt += tmp; 1381 } 1382 } else 1383 sbt = -1; 1384 1385 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1386 return (EINVAL); 1387 ni = nfds * sizeof(struct pollfd); 1388 if (ni > sizeof(smallbits)) 1389 bits = malloc(ni, M_TEMP, M_WAITOK); 1390 else 1391 bits = smallbits; 1392 error = copyin(fds, bits, ni); 1393 if (error) 1394 goto done; 1395 1396 if (uset != NULL) { 1397 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1398 &td->td_oldsigmask, 0); 1399 if (error) 1400 goto done; 1401 td->td_pflags |= TDP_OLDMASK; 1402 /* 1403 * Make sure that ast() is called on return to 1404 * usermode and TDP_OLDMASK is cleared, restoring old 1405 * sigmask. 1406 */ 1407 thread_lock(td); 1408 td->td_flags |= TDF_ASTPENDING; 1409 thread_unlock(td); 1410 } 1411 1412 seltdinit(td); 1413 /* Iterate until the timeout expires or descriptors become ready. */ 1414 for (;;) { 1415 error = pollscan(td, bits, nfds); 1416 if (error || td->td_retval[0] != 0) 1417 break; 1418 error = seltdwait(td, sbt, precision); 1419 if (error) 1420 break; 1421 error = pollrescan(td); 1422 if (error || td->td_retval[0] != 0) 1423 break; 1424 } 1425 seltdclear(td); 1426 1427 done: 1428 /* poll is not restarted after signals... */ 1429 if (error == ERESTART) 1430 error = EINTR; 1431 if (error == EWOULDBLOCK) 1432 error = 0; 1433 if (error == 0) { 1434 error = pollout(td, bits, fds, nfds); 1435 if (error) 1436 goto out; 1437 } 1438 out: 1439 if (ni > sizeof(smallbits)) 1440 free(bits, M_TEMP); 1441 return (error); 1442 } 1443 1444 int 1445 sys_ppoll(struct thread *td, struct ppoll_args *uap) 1446 { 1447 struct timespec ts, *tsp; 1448 sigset_t set, *ssp; 1449 int error; 1450 1451 if (uap->ts != NULL) { 1452 error = copyin(uap->ts, &ts, sizeof(ts)); 1453 if (error) 1454 return (error); 1455 tsp = &ts; 1456 } else 1457 tsp = NULL; 1458 if (uap->set != NULL) { 1459 error = copyin(uap->set, &set, sizeof(set)); 1460 if (error) 1461 return (error); 1462 ssp = &set; 1463 } else 1464 ssp = NULL; 1465 /* 1466 * fds is still a pointer to user space. kern_poll() will 1467 * take care of copyin that array to the kernel space. 1468 */ 1469 1470 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); 1471 } 1472 1473 static int 1474 pollrescan(struct thread *td) 1475 { 1476 struct seltd *stp; 1477 struct selfd *sfp; 1478 struct selfd *sfn; 1479 struct selinfo *si; 1480 struct filedesc *fdp; 1481 struct file *fp; 1482 struct pollfd *fd; 1483 #ifdef CAPABILITIES 1484 cap_rights_t rights; 1485 #endif 1486 int n; 1487 1488 n = 0; 1489 fdp = td->td_proc->p_fd; 1490 stp = td->td_sel; 1491 FILEDESC_SLOCK(fdp); 1492 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1493 fd = (struct pollfd *)sfp->sf_cookie; 1494 si = sfp->sf_si; 1495 selfdfree(stp, sfp); 1496 /* If the selinfo wasn't cleared the event didn't fire. */ 1497 if (si != NULL) 1498 continue; 1499 fp = fdp->fd_ofiles[fd->fd].fde_file; 1500 #ifdef CAPABILITIES 1501 if (fp == NULL || 1502 cap_check(cap_rights(fdp, fd->fd), 1503 cap_rights_init(&rights, CAP_EVENT)) != 0) 1504 #else 1505 if (fp == NULL) 1506 #endif 1507 { 1508 fd->revents = POLLNVAL; 1509 n++; 1510 continue; 1511 } 1512 1513 /* 1514 * Note: backend also returns POLLHUP and 1515 * POLLERR if appropriate. 1516 */ 1517 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1518 if (fd->revents != 0) 1519 n++; 1520 } 1521 FILEDESC_SUNLOCK(fdp); 1522 stp->st_flags = 0; 1523 td->td_retval[0] = n; 1524 return (0); 1525 } 1526 1527 1528 static int 1529 pollout(td, fds, ufds, nfd) 1530 struct thread *td; 1531 struct pollfd *fds; 1532 struct pollfd *ufds; 1533 u_int nfd; 1534 { 1535 int error = 0; 1536 u_int i = 0; 1537 u_int n = 0; 1538 1539 for (i = 0; i < nfd; i++) { 1540 error = copyout(&fds->revents, &ufds->revents, 1541 sizeof(ufds->revents)); 1542 if (error) 1543 return (error); 1544 if (fds->revents != 0) 1545 n++; 1546 fds++; 1547 ufds++; 1548 } 1549 td->td_retval[0] = n; 1550 return (0); 1551 } 1552 1553 static int 1554 pollscan(td, fds, nfd) 1555 struct thread *td; 1556 struct pollfd *fds; 1557 u_int nfd; 1558 { 1559 struct filedesc *fdp = td->td_proc->p_fd; 1560 struct file *fp; 1561 #ifdef CAPABILITIES 1562 cap_rights_t rights; 1563 #endif 1564 int i, n = 0; 1565 1566 FILEDESC_SLOCK(fdp); 1567 for (i = 0; i < nfd; i++, fds++) { 1568 if (fds->fd > fdp->fd_lastfile) { 1569 fds->revents = POLLNVAL; 1570 n++; 1571 } else if (fds->fd < 0) { 1572 fds->revents = 0; 1573 } else { 1574 fp = fdp->fd_ofiles[fds->fd].fde_file; 1575 #ifdef CAPABILITIES 1576 if (fp == NULL || 1577 cap_check(cap_rights(fdp, fds->fd), 1578 cap_rights_init(&rights, CAP_EVENT)) != 0) 1579 #else 1580 if (fp == NULL) 1581 #endif 1582 { 1583 fds->revents = POLLNVAL; 1584 n++; 1585 } else { 1586 /* 1587 * Note: backend also returns POLLHUP and 1588 * POLLERR if appropriate. 1589 */ 1590 selfdalloc(td, fds); 1591 fds->revents = fo_poll(fp, fds->events, 1592 td->td_ucred, td); 1593 /* 1594 * POSIX requires POLLOUT to be never 1595 * set simultaneously with POLLHUP. 1596 */ 1597 if ((fds->revents & POLLHUP) != 0) 1598 fds->revents &= ~POLLOUT; 1599 1600 if (fds->revents != 0) 1601 n++; 1602 } 1603 } 1604 } 1605 FILEDESC_SUNLOCK(fdp); 1606 td->td_retval[0] = n; 1607 return (0); 1608 } 1609 1610 /* 1611 * XXX This was created specifically to support netncp and netsmb. This 1612 * allows the caller to specify a socket to wait for events on. It returns 1613 * 0 if any events matched and an error otherwise. There is no way to 1614 * determine which events fired. 1615 */ 1616 int 1617 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1618 { 1619 struct timeval rtv; 1620 sbintime_t asbt, precision, rsbt; 1621 int error; 1622 1623 precision = 0; /* stupid gcc! */ 1624 if (tvp != NULL) { 1625 rtv = *tvp; 1626 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1627 rtv.tv_usec >= 1000000) 1628 return (EINVAL); 1629 if (!timevalisset(&rtv)) 1630 asbt = 0; 1631 else if (rtv.tv_sec <= INT32_MAX) { 1632 rsbt = tvtosbt(rtv); 1633 precision = rsbt; 1634 precision >>= tc_precexp; 1635 if (TIMESEL(&asbt, rsbt)) 1636 asbt += tc_tick_sbt; 1637 if (asbt <= SBT_MAX - rsbt) 1638 asbt += rsbt; 1639 else 1640 asbt = -1; 1641 } else 1642 asbt = -1; 1643 } else 1644 asbt = -1; 1645 seltdinit(td); 1646 /* 1647 * Iterate until the timeout expires or the socket becomes ready. 1648 */ 1649 for (;;) { 1650 selfdalloc(td, NULL); 1651 error = sopoll(so, events, NULL, td); 1652 /* error here is actually the ready events. */ 1653 if (error) 1654 return (0); 1655 error = seltdwait(td, asbt, precision); 1656 if (error) 1657 break; 1658 } 1659 seltdclear(td); 1660 /* XXX Duplicates ncp/smb behavior. */ 1661 if (error == ERESTART) 1662 error = 0; 1663 return (error); 1664 } 1665 1666 /* 1667 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1668 * have two select sets, one for read and another for write. 1669 */ 1670 static void 1671 selfdalloc(struct thread *td, void *cookie) 1672 { 1673 struct seltd *stp; 1674 1675 stp = td->td_sel; 1676 if (stp->st_free1 == NULL) 1677 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1678 stp->st_free1->sf_td = stp; 1679 stp->st_free1->sf_cookie = cookie; 1680 if (stp->st_free2 == NULL) 1681 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1682 stp->st_free2->sf_td = stp; 1683 stp->st_free2->sf_cookie = cookie; 1684 } 1685 1686 static void 1687 selfdfree(struct seltd *stp, struct selfd *sfp) 1688 { 1689 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1690 if (sfp->sf_si != NULL) { 1691 mtx_lock(sfp->sf_mtx); 1692 if (sfp->sf_si != NULL) { 1693 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1694 refcount_release(&sfp->sf_refs); 1695 } 1696 mtx_unlock(sfp->sf_mtx); 1697 } 1698 if (refcount_release(&sfp->sf_refs)) 1699 uma_zfree(selfd_zone, sfp); 1700 } 1701 1702 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1703 void 1704 seldrain(sip) 1705 struct selinfo *sip; 1706 { 1707 1708 /* 1709 * This feature is already provided by doselwakeup(), thus it is 1710 * enough to go for it. 1711 * Eventually, the context, should take care to avoid races 1712 * between thread calling select()/poll() and file descriptor 1713 * detaching, but, again, the races are just the same as 1714 * selwakeup(). 1715 */ 1716 doselwakeup(sip, -1); 1717 } 1718 1719 /* 1720 * Record a select request. 1721 */ 1722 void 1723 selrecord(selector, sip) 1724 struct thread *selector; 1725 struct selinfo *sip; 1726 { 1727 struct selfd *sfp; 1728 struct seltd *stp; 1729 struct mtx *mtxp; 1730 1731 stp = selector->td_sel; 1732 /* 1733 * Don't record when doing a rescan. 1734 */ 1735 if (stp->st_flags & SELTD_RESCAN) 1736 return; 1737 /* 1738 * Grab one of the preallocated descriptors. 1739 */ 1740 sfp = NULL; 1741 if ((sfp = stp->st_free1) != NULL) 1742 stp->st_free1 = NULL; 1743 else if ((sfp = stp->st_free2) != NULL) 1744 stp->st_free2 = NULL; 1745 else 1746 panic("selrecord: No free selfd on selq"); 1747 mtxp = sip->si_mtx; 1748 if (mtxp == NULL) 1749 mtxp = mtx_pool_find(mtxpool_select, sip); 1750 /* 1751 * Initialize the sfp and queue it in the thread. 1752 */ 1753 sfp->sf_si = sip; 1754 sfp->sf_mtx = mtxp; 1755 refcount_init(&sfp->sf_refs, 2); 1756 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1757 /* 1758 * Now that we've locked the sip, check for initialization. 1759 */ 1760 mtx_lock(mtxp); 1761 if (sip->si_mtx == NULL) { 1762 sip->si_mtx = mtxp; 1763 TAILQ_INIT(&sip->si_tdlist); 1764 } 1765 /* 1766 * Add this thread to the list of selfds listening on this selinfo. 1767 */ 1768 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1769 mtx_unlock(sip->si_mtx); 1770 } 1771 1772 /* Wake up a selecting thread. */ 1773 void 1774 selwakeup(sip) 1775 struct selinfo *sip; 1776 { 1777 doselwakeup(sip, -1); 1778 } 1779 1780 /* Wake up a selecting thread, and set its priority. */ 1781 void 1782 selwakeuppri(sip, pri) 1783 struct selinfo *sip; 1784 int pri; 1785 { 1786 doselwakeup(sip, pri); 1787 } 1788 1789 /* 1790 * Do a wakeup when a selectable event occurs. 1791 */ 1792 static void 1793 doselwakeup(sip, pri) 1794 struct selinfo *sip; 1795 int pri; 1796 { 1797 struct selfd *sfp; 1798 struct selfd *sfn; 1799 struct seltd *stp; 1800 1801 /* If it's not initialized there can't be any waiters. */ 1802 if (sip->si_mtx == NULL) 1803 return; 1804 /* 1805 * Locking the selinfo locks all selfds associated with it. 1806 */ 1807 mtx_lock(sip->si_mtx); 1808 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1809 /* 1810 * Once we remove this sfp from the list and clear the 1811 * sf_si seltdclear will know to ignore this si. 1812 */ 1813 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1814 sfp->sf_si = NULL; 1815 stp = sfp->sf_td; 1816 mtx_lock(&stp->st_mtx); 1817 stp->st_flags |= SELTD_PENDING; 1818 cv_broadcastpri(&stp->st_wait, pri); 1819 mtx_unlock(&stp->st_mtx); 1820 if (refcount_release(&sfp->sf_refs)) 1821 uma_zfree(selfd_zone, sfp); 1822 } 1823 mtx_unlock(sip->si_mtx); 1824 } 1825 1826 static void 1827 seltdinit(struct thread *td) 1828 { 1829 struct seltd *stp; 1830 1831 if ((stp = td->td_sel) != NULL) 1832 goto out; 1833 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1834 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1835 cv_init(&stp->st_wait, "select"); 1836 out: 1837 stp->st_flags = 0; 1838 STAILQ_INIT(&stp->st_selq); 1839 } 1840 1841 static int 1842 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1843 { 1844 struct seltd *stp; 1845 int error; 1846 1847 stp = td->td_sel; 1848 /* 1849 * An event of interest may occur while we do not hold the seltd 1850 * locked so check the pending flag before we sleep. 1851 */ 1852 mtx_lock(&stp->st_mtx); 1853 /* 1854 * Any further calls to selrecord will be a rescan. 1855 */ 1856 stp->st_flags |= SELTD_RESCAN; 1857 if (stp->st_flags & SELTD_PENDING) { 1858 mtx_unlock(&stp->st_mtx); 1859 return (0); 1860 } 1861 if (sbt == 0) 1862 error = EWOULDBLOCK; 1863 else if (sbt != -1) 1864 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 1865 sbt, precision, C_ABSOLUTE); 1866 else 1867 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1868 mtx_unlock(&stp->st_mtx); 1869 1870 return (error); 1871 } 1872 1873 void 1874 seltdfini(struct thread *td) 1875 { 1876 struct seltd *stp; 1877 1878 stp = td->td_sel; 1879 if (stp == NULL) 1880 return; 1881 if (stp->st_free1) 1882 uma_zfree(selfd_zone, stp->st_free1); 1883 if (stp->st_free2) 1884 uma_zfree(selfd_zone, stp->st_free2); 1885 td->td_sel = NULL; 1886 cv_destroy(&stp->st_wait); 1887 mtx_destroy(&stp->st_mtx); 1888 free(stp, M_SELECT); 1889 } 1890 1891 /* 1892 * Remove the references to the thread from all of the objects we were 1893 * polling. 1894 */ 1895 static void 1896 seltdclear(struct thread *td) 1897 { 1898 struct seltd *stp; 1899 struct selfd *sfp; 1900 struct selfd *sfn; 1901 1902 stp = td->td_sel; 1903 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1904 selfdfree(stp, sfp); 1905 stp->st_flags = 0; 1906 } 1907 1908 static void selectinit(void *); 1909 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1910 static void 1911 selectinit(void *dummy __unused) 1912 { 1913 1914 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, 1915 NULL, NULL, UMA_ALIGN_PTR, 0); 1916 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 1917 } 1918 1919 /* 1920 * Set up a syscall return value that follows the convention specified for 1921 * posix_* functions. 1922 */ 1923 int 1924 kern_posix_error(struct thread *td, int error) 1925 { 1926 1927 if (error <= 0) 1928 return (error); 1929 td->td_errno = error; 1930 td->td_pflags |= TDP_NERRNO; 1931 td->td_retval[0] = error; 1932 return (0); 1933 } 1934