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(struct thread *td, struct read_args *uap) 192 { 193 struct uio auio; 194 struct iovec aiov; 195 int error; 196 197 if (uap->nbyte > IOSIZE_MAX) 198 return (EINVAL); 199 aiov.iov_base = uap->buf; 200 aiov.iov_len = uap->nbyte; 201 auio.uio_iov = &aiov; 202 auio.uio_iovcnt = 1; 203 auio.uio_resid = uap->nbyte; 204 auio.uio_segflg = UIO_USERSPACE; 205 error = kern_readv(td, uap->fd, &auio); 206 return (error); 207 } 208 209 /* 210 * Positioned read system call 211 */ 212 #ifndef _SYS_SYSPROTO_H_ 213 struct pread_args { 214 int fd; 215 void *buf; 216 size_t nbyte; 217 int pad; 218 off_t offset; 219 }; 220 #endif 221 int 222 sys_pread(struct thread *td, struct pread_args *uap) 223 { 224 225 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 226 } 227 228 int 229 kern_pread(struct thread *td, int fd, void *buf, size_t nbyte, off_t offset) 230 { 231 struct uio auio; 232 struct iovec aiov; 233 int error; 234 235 if (nbyte > IOSIZE_MAX) 236 return (EINVAL); 237 aiov.iov_base = buf; 238 aiov.iov_len = nbyte; 239 auio.uio_iov = &aiov; 240 auio.uio_iovcnt = 1; 241 auio.uio_resid = nbyte; 242 auio.uio_segflg = UIO_USERSPACE; 243 error = kern_preadv(td, fd, &auio, offset); 244 return (error); 245 } 246 247 #if defined(COMPAT_FREEBSD6) 248 int 249 freebsd6_pread(struct thread *td, struct freebsd6_pread_args *uap) 250 { 251 252 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 253 } 254 #endif 255 256 /* 257 * Scatter read system call. 258 */ 259 #ifndef _SYS_SYSPROTO_H_ 260 struct readv_args { 261 int fd; 262 struct iovec *iovp; 263 u_int iovcnt; 264 }; 265 #endif 266 int 267 sys_readv(struct thread *td, struct readv_args *uap) 268 { 269 struct uio *auio; 270 int error; 271 272 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 273 if (error) 274 return (error); 275 error = kern_readv(td, uap->fd, auio); 276 free(auio, M_IOV); 277 return (error); 278 } 279 280 int 281 kern_readv(struct thread *td, int fd, struct uio *auio) 282 { 283 struct file *fp; 284 int error; 285 286 error = fget_read(td, fd, &cap_read_rights, &fp); 287 if (error) 288 return (error); 289 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 290 fdrop(fp, td); 291 return (error); 292 } 293 294 /* 295 * Scatter positioned read system call. 296 */ 297 #ifndef _SYS_SYSPROTO_H_ 298 struct preadv_args { 299 int fd; 300 struct iovec *iovp; 301 u_int iovcnt; 302 off_t offset; 303 }; 304 #endif 305 int 306 sys_preadv(struct thread *td, struct preadv_args *uap) 307 { 308 struct uio *auio; 309 int error; 310 311 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 312 if (error) 313 return (error); 314 error = kern_preadv(td, uap->fd, auio, uap->offset); 315 free(auio, M_IOV); 316 return (error); 317 } 318 319 int 320 kern_preadv(struct thread *td, int fd, struct uio *auio, off_t offset) 321 { 322 struct file *fp; 323 int error; 324 325 error = fget_read(td, fd, &cap_pread_rights, &fp); 326 if (error) 327 return (error); 328 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 329 error = ESPIPE; 330 else if (offset < 0 && 331 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 332 error = EINVAL; 333 else 334 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 335 fdrop(fp, td); 336 return (error); 337 } 338 339 /* 340 * Common code for readv and preadv that reads data in 341 * from a file using the passed in uio, offset, and flags. 342 */ 343 static int 344 dofileread(struct thread *td, int fd, struct file *fp, struct uio *auio, 345 off_t offset, int flags) 346 { 347 ssize_t cnt; 348 int error; 349 #ifdef KTRACE 350 struct uio *ktruio = NULL; 351 #endif 352 353 AUDIT_ARG_FD(fd); 354 355 /* Finish zero length reads right here */ 356 if (auio->uio_resid == 0) { 357 td->td_retval[0] = 0; 358 return (0); 359 } 360 auio->uio_rw = UIO_READ; 361 auio->uio_offset = offset; 362 auio->uio_td = td; 363 #ifdef KTRACE 364 if (KTRPOINT(td, KTR_GENIO)) 365 ktruio = cloneuio(auio); 366 #endif 367 cnt = auio->uio_resid; 368 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 369 if (auio->uio_resid != cnt && (error == ERESTART || 370 error == EINTR || error == EWOULDBLOCK)) 371 error = 0; 372 } 373 cnt -= auio->uio_resid; 374 #ifdef KTRACE 375 if (ktruio != NULL) { 376 ktruio->uio_resid = cnt; 377 ktrgenio(fd, UIO_READ, ktruio, error); 378 } 379 #endif 380 td->td_retval[0] = cnt; 381 return (error); 382 } 383 384 #ifndef _SYS_SYSPROTO_H_ 385 struct write_args { 386 int fd; 387 const void *buf; 388 size_t nbyte; 389 }; 390 #endif 391 int 392 sys_write(struct thread *td, struct write_args *uap) 393 { 394 struct uio auio; 395 struct iovec aiov; 396 int error; 397 398 if (uap->nbyte > IOSIZE_MAX) 399 return (EINVAL); 400 aiov.iov_base = (void *)(uintptr_t)uap->buf; 401 aiov.iov_len = uap->nbyte; 402 auio.uio_iov = &aiov; 403 auio.uio_iovcnt = 1; 404 auio.uio_resid = uap->nbyte; 405 auio.uio_segflg = UIO_USERSPACE; 406 error = kern_writev(td, uap->fd, &auio); 407 return (error); 408 } 409 410 /* 411 * Positioned write system call. 412 */ 413 #ifndef _SYS_SYSPROTO_H_ 414 struct pwrite_args { 415 int fd; 416 const void *buf; 417 size_t nbyte; 418 int pad; 419 off_t offset; 420 }; 421 #endif 422 int 423 sys_pwrite(struct thread *td, struct pwrite_args *uap) 424 { 425 426 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 427 } 428 429 int 430 kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte, 431 off_t offset) 432 { 433 struct uio auio; 434 struct iovec aiov; 435 int error; 436 437 if (nbyte > IOSIZE_MAX) 438 return (EINVAL); 439 aiov.iov_base = (void *)(uintptr_t)buf; 440 aiov.iov_len = nbyte; 441 auio.uio_iov = &aiov; 442 auio.uio_iovcnt = 1; 443 auio.uio_resid = nbyte; 444 auio.uio_segflg = UIO_USERSPACE; 445 error = kern_pwritev(td, fd, &auio, offset); 446 return (error); 447 } 448 449 #if defined(COMPAT_FREEBSD6) 450 int 451 freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap) 452 { 453 454 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 455 } 456 #endif 457 458 /* 459 * Gather write system call. 460 */ 461 #ifndef _SYS_SYSPROTO_H_ 462 struct writev_args { 463 int fd; 464 struct iovec *iovp; 465 u_int iovcnt; 466 }; 467 #endif 468 int 469 sys_writev(struct thread *td, struct writev_args *uap) 470 { 471 struct uio *auio; 472 int error; 473 474 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 475 if (error) 476 return (error); 477 error = kern_writev(td, uap->fd, auio); 478 free(auio, M_IOV); 479 return (error); 480 } 481 482 int 483 kern_writev(struct thread *td, int fd, struct uio *auio) 484 { 485 struct file *fp; 486 int error; 487 488 error = fget_write(td, fd, &cap_write_rights, &fp); 489 if (error) 490 return (error); 491 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 492 fdrop(fp, td); 493 return (error); 494 } 495 496 /* 497 * Gather positioned write system call. 498 */ 499 #ifndef _SYS_SYSPROTO_H_ 500 struct pwritev_args { 501 int fd; 502 struct iovec *iovp; 503 u_int iovcnt; 504 off_t offset; 505 }; 506 #endif 507 int 508 sys_pwritev(struct thread *td, struct pwritev_args *uap) 509 { 510 struct uio *auio; 511 int error; 512 513 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 514 if (error) 515 return (error); 516 error = kern_pwritev(td, uap->fd, auio, uap->offset); 517 free(auio, M_IOV); 518 return (error); 519 } 520 521 int 522 kern_pwritev(struct thread *td, int fd, struct uio *auio, off_t offset) 523 { 524 struct file *fp; 525 int error; 526 527 error = fget_write(td, fd, &cap_pwrite_rights, &fp); 528 if (error) 529 return (error); 530 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 531 error = ESPIPE; 532 else if (offset < 0 && 533 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 534 error = EINVAL; 535 else 536 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 537 fdrop(fp, td); 538 return (error); 539 } 540 541 /* 542 * Common code for writev and pwritev that writes data to 543 * a file using the passed in uio, offset, and flags. 544 */ 545 static int 546 dofilewrite(struct thread *td, int fd, struct file *fp, struct uio *auio, 547 off_t offset, int flags) 548 { 549 ssize_t cnt; 550 int error; 551 #ifdef KTRACE 552 struct uio *ktruio = NULL; 553 #endif 554 555 AUDIT_ARG_FD(fd); 556 auio->uio_rw = UIO_WRITE; 557 auio->uio_td = td; 558 auio->uio_offset = offset; 559 #ifdef KTRACE 560 if (KTRPOINT(td, KTR_GENIO)) 561 ktruio = cloneuio(auio); 562 #endif 563 cnt = auio->uio_resid; 564 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 565 if (auio->uio_resid != cnt && (error == ERESTART || 566 error == EINTR || error == EWOULDBLOCK)) 567 error = 0; 568 /* Socket layer is responsible for issuing SIGPIPE. */ 569 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 570 PROC_LOCK(td->td_proc); 571 tdsignal(td, SIGPIPE); 572 PROC_UNLOCK(td->td_proc); 573 } 574 } 575 cnt -= auio->uio_resid; 576 #ifdef KTRACE 577 if (ktruio != NULL) { 578 ktruio->uio_resid = cnt; 579 ktrgenio(fd, UIO_WRITE, ktruio, error); 580 } 581 #endif 582 td->td_retval[0] = cnt; 583 return (error); 584 } 585 586 /* 587 * Truncate a file given a file descriptor. 588 * 589 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 590 * descriptor isn't writable. 591 */ 592 int 593 kern_ftruncate(struct thread *td, int fd, off_t length) 594 { 595 struct file *fp; 596 int error; 597 598 AUDIT_ARG_FD(fd); 599 if (length < 0) 600 return (EINVAL); 601 error = fget(td, fd, &cap_ftruncate_rights, &fp); 602 if (error) 603 return (error); 604 AUDIT_ARG_FILE(td->td_proc, fp); 605 if (!(fp->f_flag & FWRITE)) { 606 fdrop(fp, td); 607 return (EINVAL); 608 } 609 error = fo_truncate(fp, length, td->td_ucred, td); 610 fdrop(fp, td); 611 return (error); 612 } 613 614 #ifndef _SYS_SYSPROTO_H_ 615 struct ftruncate_args { 616 int fd; 617 int pad; 618 off_t length; 619 }; 620 #endif 621 int 622 sys_ftruncate(struct thread *td, struct ftruncate_args *uap) 623 { 624 625 return (kern_ftruncate(td, uap->fd, uap->length)); 626 } 627 628 #if defined(COMPAT_43) 629 #ifndef _SYS_SYSPROTO_H_ 630 struct oftruncate_args { 631 int fd; 632 long length; 633 }; 634 #endif 635 int 636 oftruncate(struct thread *td, struct oftruncate_args *uap) 637 { 638 639 return (kern_ftruncate(td, uap->fd, uap->length)); 640 } 641 #endif /* COMPAT_43 */ 642 643 #ifndef _SYS_SYSPROTO_H_ 644 struct ioctl_args { 645 int fd; 646 u_long com; 647 caddr_t data; 648 }; 649 #endif 650 /* ARGSUSED */ 651 int 652 sys_ioctl(struct thread *td, struct ioctl_args *uap) 653 { 654 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); 655 u_long com; 656 int arg, error; 657 u_int size; 658 caddr_t data; 659 660 if (uap->com > 0xffffffff) { 661 printf( 662 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 663 td->td_proc->p_pid, td->td_name, uap->com); 664 uap->com &= 0xffffffff; 665 } 666 com = uap->com; 667 668 /* 669 * Interpret high order word to find amount of data to be 670 * copied to/from the user's address space. 671 */ 672 size = IOCPARM_LEN(com); 673 if ((size > IOCPARM_MAX) || 674 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 675 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 676 ((com & IOC_OUT) && size == 0) || 677 #else 678 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 679 #endif 680 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 681 return (ENOTTY); 682 683 if (size > 0) { 684 if (com & IOC_VOID) { 685 /* Integer argument. */ 686 arg = (intptr_t)uap->data; 687 data = (void *)&arg; 688 size = 0; 689 } else { 690 if (size > SYS_IOCTL_SMALL_SIZE) 691 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 692 else 693 data = smalldata; 694 } 695 } else 696 data = (void *)&uap->data; 697 if (com & IOC_IN) { 698 error = copyin(uap->data, data, (u_int)size); 699 if (error != 0) 700 goto out; 701 } else if (com & IOC_OUT) { 702 /* 703 * Zero the buffer so the user always 704 * gets back something deterministic. 705 */ 706 bzero(data, size); 707 } 708 709 error = kern_ioctl(td, uap->fd, com, data); 710 711 if (error == 0 && (com & IOC_OUT)) 712 error = copyout(data, uap->data, (u_int)size); 713 714 out: 715 if (size > SYS_IOCTL_SMALL_SIZE) 716 free(data, M_IOCTLOPS); 717 return (error); 718 } 719 720 int 721 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 722 { 723 struct file *fp; 724 struct filedesc *fdp; 725 int error, tmp, locked; 726 727 AUDIT_ARG_FD(fd); 728 AUDIT_ARG_CMD(com); 729 730 fdp = td->td_proc->p_fd; 731 732 switch (com) { 733 case FIONCLEX: 734 case FIOCLEX: 735 FILEDESC_XLOCK(fdp); 736 locked = LA_XLOCKED; 737 break; 738 default: 739 #ifdef CAPABILITIES 740 FILEDESC_SLOCK(fdp); 741 locked = LA_SLOCKED; 742 #else 743 locked = LA_UNLOCKED; 744 #endif 745 break; 746 } 747 748 #ifdef CAPABILITIES 749 if ((fp = fget_locked(fdp, fd)) == NULL) { 750 error = EBADF; 751 goto out; 752 } 753 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 754 fp = NULL; /* fhold() was not called yet */ 755 goto out; 756 } 757 if (!fhold(fp)) { 758 error = EBADF; 759 fp = NULL; 760 goto out; 761 } 762 if (locked == LA_SLOCKED) { 763 FILEDESC_SUNLOCK(fdp); 764 locked = LA_UNLOCKED; 765 } 766 #else 767 error = fget(td, fd, &cap_ioctl_rights, &fp); 768 if (error != 0) { 769 fp = NULL; 770 goto out; 771 } 772 #endif 773 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 774 error = EBADF; 775 goto out; 776 } 777 778 switch (com) { 779 case FIONCLEX: 780 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 781 goto out; 782 case FIOCLEX: 783 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 784 goto out; 785 case FIONBIO: 786 if ((tmp = *(int *)data)) 787 atomic_set_int(&fp->f_flag, FNONBLOCK); 788 else 789 atomic_clear_int(&fp->f_flag, FNONBLOCK); 790 data = (void *)&tmp; 791 break; 792 case FIOASYNC: 793 if ((tmp = *(int *)data)) 794 atomic_set_int(&fp->f_flag, FASYNC); 795 else 796 atomic_clear_int(&fp->f_flag, FASYNC); 797 data = (void *)&tmp; 798 break; 799 } 800 801 error = fo_ioctl(fp, com, data, td->td_ucred, td); 802 out: 803 switch (locked) { 804 case LA_XLOCKED: 805 FILEDESC_XUNLOCK(fdp); 806 break; 807 #ifdef CAPABILITIES 808 case LA_SLOCKED: 809 FILEDESC_SUNLOCK(fdp); 810 break; 811 #endif 812 default: 813 FILEDESC_UNLOCK_ASSERT(fdp); 814 break; 815 } 816 if (fp != NULL) 817 fdrop(fp, td); 818 return (error); 819 } 820 821 int 822 poll_no_poll(int events) 823 { 824 /* 825 * Return true for read/write. If the user asked for something 826 * special, return POLLNVAL, so that clients have a way of 827 * determining reliably whether or not the extended 828 * functionality is present without hard-coding knowledge 829 * of specific filesystem implementations. 830 */ 831 if (events & ~POLLSTANDARD) 832 return (POLLNVAL); 833 834 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 835 } 836 837 int 838 sys_pselect(struct thread *td, struct pselect_args *uap) 839 { 840 struct timespec ts; 841 struct timeval tv, *tvp; 842 sigset_t set, *uset; 843 int error; 844 845 if (uap->ts != NULL) { 846 error = copyin(uap->ts, &ts, sizeof(ts)); 847 if (error != 0) 848 return (error); 849 TIMESPEC_TO_TIMEVAL(&tv, &ts); 850 tvp = &tv; 851 } else 852 tvp = NULL; 853 if (uap->sm != NULL) { 854 error = copyin(uap->sm, &set, sizeof(set)); 855 if (error != 0) 856 return (error); 857 uset = &set; 858 } else 859 uset = NULL; 860 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 861 uset, NFDBITS)); 862 } 863 864 int 865 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 866 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 867 { 868 int error; 869 870 if (uset != NULL) { 871 error = kern_sigprocmask(td, SIG_SETMASK, uset, 872 &td->td_oldsigmask, 0); 873 if (error != 0) 874 return (error); 875 td->td_pflags |= TDP_OLDMASK; 876 /* 877 * Make sure that ast() is called on return to 878 * usermode and TDP_OLDMASK is cleared, restoring old 879 * sigmask. 880 */ 881 thread_lock(td); 882 td->td_flags |= TDF_ASTPENDING; 883 thread_unlock(td); 884 } 885 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 886 return (error); 887 } 888 889 #ifndef _SYS_SYSPROTO_H_ 890 struct select_args { 891 int nd; 892 fd_set *in, *ou, *ex; 893 struct timeval *tv; 894 }; 895 #endif 896 int 897 sys_select(struct thread *td, struct select_args *uap) 898 { 899 struct timeval tv, *tvp; 900 int error; 901 902 if (uap->tv != NULL) { 903 error = copyin(uap->tv, &tv, sizeof(tv)); 904 if (error) 905 return (error); 906 tvp = &tv; 907 } else 908 tvp = NULL; 909 910 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 911 NFDBITS)); 912 } 913 914 /* 915 * In the unlikely case when user specified n greater then the last 916 * open file descriptor, check that no bits are set after the last 917 * valid fd. We must return EBADF if any is set. 918 * 919 * There are applications that rely on the behaviour. 920 * 921 * nd is fd_lastfile + 1. 922 */ 923 static int 924 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 925 { 926 char *addr, *oaddr; 927 int b, i, res; 928 uint8_t bits; 929 930 if (nd >= ndu || fd_in == NULL) 931 return (0); 932 933 oaddr = NULL; 934 bits = 0; /* silence gcc */ 935 for (i = nd; i < ndu; i++) { 936 b = i / NBBY; 937 #if BYTE_ORDER == LITTLE_ENDIAN 938 addr = (char *)fd_in + b; 939 #else 940 addr = (char *)fd_in; 941 if (abi_nfdbits == NFDBITS) { 942 addr += rounddown(b, sizeof(fd_mask)) + 943 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 944 } else { 945 addr += rounddown(b, sizeof(uint32_t)) + 946 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 947 } 948 #endif 949 if (addr != oaddr) { 950 res = fubyte(addr); 951 if (res == -1) 952 return (EFAULT); 953 oaddr = addr; 954 bits = res; 955 } 956 if ((bits & (1 << (i % NBBY))) != 0) 957 return (EBADF); 958 } 959 return (0); 960 } 961 962 int 963 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 964 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 965 { 966 struct filedesc *fdp; 967 /* 968 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 969 * infds with the new FD_SETSIZE of 1024, and more than enough for 970 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 971 * of 256. 972 */ 973 fd_mask s_selbits[howmany(2048, NFDBITS)]; 974 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 975 struct timeval rtv; 976 sbintime_t asbt, precision, rsbt; 977 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 978 int error, lf, ndu; 979 980 if (nd < 0) 981 return (EINVAL); 982 fdp = td->td_proc->p_fd; 983 ndu = nd; 984 lf = fdp->fd_lastfile; 985 if (nd > lf + 1) 986 nd = lf + 1; 987 988 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 989 if (error != 0) 990 return (error); 991 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 992 if (error != 0) 993 return (error); 994 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 995 if (error != 0) 996 return (error); 997 998 /* 999 * Allocate just enough bits for the non-null fd_sets. Use the 1000 * preallocated auto buffer if possible. 1001 */ 1002 nfdbits = roundup(nd, NFDBITS); 1003 ncpbytes = nfdbits / NBBY; 1004 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 1005 nbufbytes = 0; 1006 if (fd_in != NULL) 1007 nbufbytes += 2 * ncpbytes; 1008 if (fd_ou != NULL) 1009 nbufbytes += 2 * ncpbytes; 1010 if (fd_ex != NULL) 1011 nbufbytes += 2 * ncpbytes; 1012 if (nbufbytes <= sizeof s_selbits) 1013 selbits = &s_selbits[0]; 1014 else 1015 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1016 1017 /* 1018 * Assign pointers into the bit buffers and fetch the input bits. 1019 * Put the output buffers together so that they can be bzeroed 1020 * together. 1021 */ 1022 sbp = selbits; 1023 #define getbits(name, x) \ 1024 do { \ 1025 if (name == NULL) { \ 1026 ibits[x] = NULL; \ 1027 obits[x] = NULL; \ 1028 } else { \ 1029 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1030 obits[x] = sbp; \ 1031 sbp += ncpbytes / sizeof *sbp; \ 1032 error = copyin(name, ibits[x], ncpubytes); \ 1033 if (error != 0) \ 1034 goto done; \ 1035 if (ncpbytes != ncpubytes) \ 1036 bzero((char *)ibits[x] + ncpubytes, \ 1037 ncpbytes - ncpubytes); \ 1038 } \ 1039 } while (0) 1040 getbits(fd_in, 0); 1041 getbits(fd_ou, 1); 1042 getbits(fd_ex, 2); 1043 #undef getbits 1044 1045 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1046 /* 1047 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1048 * we are running under 32-bit emulation. This should be more 1049 * generic. 1050 */ 1051 #define swizzle_fdset(bits) \ 1052 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1053 int i; \ 1054 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1055 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1056 } 1057 #else 1058 #define swizzle_fdset(bits) 1059 #endif 1060 1061 /* Make sure the bit order makes it through an ABI transition */ 1062 swizzle_fdset(ibits[0]); 1063 swizzle_fdset(ibits[1]); 1064 swizzle_fdset(ibits[2]); 1065 1066 if (nbufbytes != 0) 1067 bzero(selbits, nbufbytes / 2); 1068 1069 precision = 0; 1070 if (tvp != NULL) { 1071 rtv = *tvp; 1072 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1073 rtv.tv_usec >= 1000000) { 1074 error = EINVAL; 1075 goto done; 1076 } 1077 if (!timevalisset(&rtv)) 1078 asbt = 0; 1079 else if (rtv.tv_sec <= INT32_MAX) { 1080 rsbt = tvtosbt(rtv); 1081 precision = rsbt; 1082 precision >>= tc_precexp; 1083 if (TIMESEL(&asbt, rsbt)) 1084 asbt += tc_tick_sbt; 1085 if (asbt <= SBT_MAX - rsbt) 1086 asbt += rsbt; 1087 else 1088 asbt = -1; 1089 } else 1090 asbt = -1; 1091 } else 1092 asbt = -1; 1093 seltdinit(td); 1094 /* Iterate until the timeout expires or descriptors become ready. */ 1095 for (;;) { 1096 error = selscan(td, ibits, obits, nd); 1097 if (error || td->td_retval[0] != 0) 1098 break; 1099 error = seltdwait(td, asbt, precision); 1100 if (error) 1101 break; 1102 error = selrescan(td, ibits, obits); 1103 if (error || td->td_retval[0] != 0) 1104 break; 1105 } 1106 seltdclear(td); 1107 1108 done: 1109 /* select is not restarted after signals... */ 1110 if (error == ERESTART) 1111 error = EINTR; 1112 if (error == EWOULDBLOCK) 1113 error = 0; 1114 1115 /* swizzle bit order back, if necessary */ 1116 swizzle_fdset(obits[0]); 1117 swizzle_fdset(obits[1]); 1118 swizzle_fdset(obits[2]); 1119 #undef swizzle_fdset 1120 1121 #define putbits(name, x) \ 1122 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1123 error = error2; 1124 if (error == 0) { 1125 int error2; 1126 1127 putbits(fd_in, 0); 1128 putbits(fd_ou, 1); 1129 putbits(fd_ex, 2); 1130 #undef putbits 1131 } 1132 if (selbits != &s_selbits[0]) 1133 free(selbits, M_SELECT); 1134 1135 return (error); 1136 } 1137 /* 1138 * Convert a select bit set to poll flags. 1139 * 1140 * The backend always returns POLLHUP/POLLERR if appropriate and we 1141 * return this as a set bit in any set. 1142 */ 1143 static int select_flags[3] = { 1144 POLLRDNORM | POLLHUP | POLLERR, 1145 POLLWRNORM | POLLHUP | POLLERR, 1146 POLLRDBAND | POLLERR 1147 }; 1148 1149 /* 1150 * Compute the fo_poll flags required for a fd given by the index and 1151 * bit position in the fd_mask array. 1152 */ 1153 static __inline int 1154 selflags(fd_mask **ibits, int idx, fd_mask bit) 1155 { 1156 int flags; 1157 int msk; 1158 1159 flags = 0; 1160 for (msk = 0; msk < 3; msk++) { 1161 if (ibits[msk] == NULL) 1162 continue; 1163 if ((ibits[msk][idx] & bit) == 0) 1164 continue; 1165 flags |= select_flags[msk]; 1166 } 1167 return (flags); 1168 } 1169 1170 /* 1171 * Set the appropriate output bits given a mask of fired events and the 1172 * input bits originally requested. 1173 */ 1174 static __inline int 1175 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1176 { 1177 int msk; 1178 int n; 1179 1180 n = 0; 1181 for (msk = 0; msk < 3; msk++) { 1182 if ((events & select_flags[msk]) == 0) 1183 continue; 1184 if (ibits[msk] == NULL) 1185 continue; 1186 if ((ibits[msk][idx] & bit) == 0) 1187 continue; 1188 /* 1189 * XXX Check for a duplicate set. This can occur because a 1190 * socket calls selrecord() twice for each poll() call 1191 * resulting in two selfds per real fd. selrescan() will 1192 * call selsetbits twice as a result. 1193 */ 1194 if ((obits[msk][idx] & bit) != 0) 1195 continue; 1196 obits[msk][idx] |= bit; 1197 n++; 1198 } 1199 1200 return (n); 1201 } 1202 1203 static __inline int 1204 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) 1205 { 1206 1207 return (fget_unlocked(fdp, fd, &cap_event_rights, fpp, NULL)); 1208 } 1209 1210 /* 1211 * Traverse the list of fds attached to this thread's seltd and check for 1212 * completion. 1213 */ 1214 static int 1215 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1216 { 1217 struct filedesc *fdp; 1218 struct selinfo *si; 1219 struct seltd *stp; 1220 struct selfd *sfp; 1221 struct selfd *sfn; 1222 struct file *fp; 1223 fd_mask bit; 1224 int fd, ev, n, idx; 1225 int error; 1226 1227 fdp = td->td_proc->p_fd; 1228 stp = td->td_sel; 1229 n = 0; 1230 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1231 fd = (int)(uintptr_t)sfp->sf_cookie; 1232 si = sfp->sf_si; 1233 selfdfree(stp, sfp); 1234 /* If the selinfo wasn't cleared the event didn't fire. */ 1235 if (si != NULL) 1236 continue; 1237 error = getselfd_cap(fdp, fd, &fp); 1238 if (error) 1239 return (error); 1240 idx = fd / NFDBITS; 1241 bit = (fd_mask)1 << (fd % NFDBITS); 1242 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1243 fdrop(fp, td); 1244 if (ev != 0) 1245 n += selsetbits(ibits, obits, idx, bit, ev); 1246 } 1247 stp->st_flags = 0; 1248 td->td_retval[0] = n; 1249 return (0); 1250 } 1251 1252 /* 1253 * Perform the initial filedescriptor scan and register ourselves with 1254 * each selinfo. 1255 */ 1256 static int 1257 selscan(struct thread *td, fd_mask **ibits, fd_mask **obits, int nfd) 1258 { 1259 struct filedesc *fdp; 1260 struct file *fp; 1261 fd_mask bit; 1262 int ev, flags, end, fd; 1263 int n, idx; 1264 int error; 1265 1266 fdp = td->td_proc->p_fd; 1267 n = 0; 1268 for (idx = 0, fd = 0; fd < nfd; idx++) { 1269 end = imin(fd + NFDBITS, nfd); 1270 for (bit = 1; fd < end; bit <<= 1, fd++) { 1271 /* Compute the list of events we're interested in. */ 1272 flags = selflags(ibits, idx, bit); 1273 if (flags == 0) 1274 continue; 1275 error = getselfd_cap(fdp, fd, &fp); 1276 if (error) 1277 return (error); 1278 selfdalloc(td, (void *)(uintptr_t)fd); 1279 ev = fo_poll(fp, flags, td->td_ucred, td); 1280 fdrop(fp, td); 1281 if (ev != 0) 1282 n += selsetbits(ibits, obits, idx, bit, ev); 1283 } 1284 } 1285 1286 td->td_retval[0] = n; 1287 return (0); 1288 } 1289 1290 int 1291 sys_poll(struct thread *td, struct poll_args *uap) 1292 { 1293 struct timespec ts, *tsp; 1294 1295 if (uap->timeout != INFTIM) { 1296 if (uap->timeout < 0) 1297 return (EINVAL); 1298 ts.tv_sec = uap->timeout / 1000; 1299 ts.tv_nsec = (uap->timeout % 1000) * 1000000; 1300 tsp = &ts; 1301 } else 1302 tsp = NULL; 1303 1304 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); 1305 } 1306 1307 int 1308 kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds, 1309 struct timespec *tsp, sigset_t *uset) 1310 { 1311 struct pollfd *kfds; 1312 struct pollfd stackfds[32]; 1313 sbintime_t sbt, precision, tmp; 1314 time_t over; 1315 struct timespec ts; 1316 int error; 1317 1318 precision = 0; 1319 if (tsp != NULL) { 1320 if (tsp->tv_sec < 0) 1321 return (EINVAL); 1322 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000) 1323 return (EINVAL); 1324 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1325 sbt = 0; 1326 else { 1327 ts = *tsp; 1328 if (ts.tv_sec > INT32_MAX / 2) { 1329 over = ts.tv_sec - INT32_MAX / 2; 1330 ts.tv_sec -= over; 1331 } else 1332 over = 0; 1333 tmp = tstosbt(ts); 1334 precision = tmp; 1335 precision >>= tc_precexp; 1336 if (TIMESEL(&sbt, tmp)) 1337 sbt += tc_tick_sbt; 1338 sbt += tmp; 1339 } 1340 } else 1341 sbt = -1; 1342 1343 /* 1344 * This is kinda bogus. We have fd limits, but that is not 1345 * really related to the size of the pollfd array. Make sure 1346 * we let the process use at least FD_SETSIZE entries and at 1347 * least enough for the system-wide limits. We want to be reasonably 1348 * safe, but not overly restrictive. 1349 */ 1350 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1351 return (EINVAL); 1352 if (nfds > nitems(stackfds)) 1353 kfds = mallocarray(nfds, sizeof(*kfds), M_TEMP, M_WAITOK); 1354 else 1355 kfds = stackfds; 1356 error = copyin(ufds, kfds, nfds * sizeof(*kfds)); 1357 if (error) 1358 goto done; 1359 1360 if (uset != NULL) { 1361 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1362 &td->td_oldsigmask, 0); 1363 if (error) 1364 goto done; 1365 td->td_pflags |= TDP_OLDMASK; 1366 /* 1367 * Make sure that ast() is called on return to 1368 * usermode and TDP_OLDMASK is cleared, restoring old 1369 * sigmask. 1370 */ 1371 thread_lock(td); 1372 td->td_flags |= TDF_ASTPENDING; 1373 thread_unlock(td); 1374 } 1375 1376 seltdinit(td); 1377 /* Iterate until the timeout expires or descriptors become ready. */ 1378 for (;;) { 1379 error = pollscan(td, kfds, nfds); 1380 if (error || td->td_retval[0] != 0) 1381 break; 1382 error = seltdwait(td, sbt, precision); 1383 if (error) 1384 break; 1385 error = pollrescan(td); 1386 if (error || td->td_retval[0] != 0) 1387 break; 1388 } 1389 seltdclear(td); 1390 1391 done: 1392 /* poll is not restarted after signals... */ 1393 if (error == ERESTART) 1394 error = EINTR; 1395 if (error == EWOULDBLOCK) 1396 error = 0; 1397 if (error == 0) { 1398 error = pollout(td, kfds, ufds, nfds); 1399 if (error) 1400 goto out; 1401 } 1402 out: 1403 if (nfds > nitems(stackfds)) 1404 free(kfds, M_TEMP); 1405 return (error); 1406 } 1407 1408 int 1409 sys_ppoll(struct thread *td, struct ppoll_args *uap) 1410 { 1411 struct timespec ts, *tsp; 1412 sigset_t set, *ssp; 1413 int error; 1414 1415 if (uap->ts != NULL) { 1416 error = copyin(uap->ts, &ts, sizeof(ts)); 1417 if (error) 1418 return (error); 1419 tsp = &ts; 1420 } else 1421 tsp = NULL; 1422 if (uap->set != NULL) { 1423 error = copyin(uap->set, &set, sizeof(set)); 1424 if (error) 1425 return (error); 1426 ssp = &set; 1427 } else 1428 ssp = NULL; 1429 /* 1430 * fds is still a pointer to user space. kern_poll() will 1431 * take care of copyin that array to the kernel space. 1432 */ 1433 1434 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); 1435 } 1436 1437 static int 1438 pollrescan(struct thread *td) 1439 { 1440 struct seltd *stp; 1441 struct selfd *sfp; 1442 struct selfd *sfn; 1443 struct selinfo *si; 1444 struct filedesc *fdp; 1445 struct file *fp; 1446 struct pollfd *fd; 1447 int n; 1448 1449 n = 0; 1450 fdp = td->td_proc->p_fd; 1451 stp = td->td_sel; 1452 FILEDESC_SLOCK(fdp); 1453 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1454 fd = (struct pollfd *)sfp->sf_cookie; 1455 si = sfp->sf_si; 1456 selfdfree(stp, sfp); 1457 /* If the selinfo wasn't cleared the event didn't fire. */ 1458 if (si != NULL) 1459 continue; 1460 fp = fdp->fd_ofiles[fd->fd].fde_file; 1461 #ifdef CAPABILITIES 1462 if (fp == NULL || 1463 cap_check(cap_rights(fdp, fd->fd), &cap_event_rights) != 0) 1464 #else 1465 if (fp == NULL) 1466 #endif 1467 { 1468 fd->revents = POLLNVAL; 1469 n++; 1470 continue; 1471 } 1472 1473 /* 1474 * Note: backend also returns POLLHUP and 1475 * POLLERR if appropriate. 1476 */ 1477 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1478 if (fd->revents != 0) 1479 n++; 1480 } 1481 FILEDESC_SUNLOCK(fdp); 1482 stp->st_flags = 0; 1483 td->td_retval[0] = n; 1484 return (0); 1485 } 1486 1487 1488 static int 1489 pollout(struct thread *td, struct pollfd *fds, struct pollfd *ufds, u_int nfd) 1490 { 1491 int error = 0; 1492 u_int i = 0; 1493 u_int n = 0; 1494 1495 for (i = 0; i < nfd; i++) { 1496 error = copyout(&fds->revents, &ufds->revents, 1497 sizeof(ufds->revents)); 1498 if (error) 1499 return (error); 1500 if (fds->revents != 0) 1501 n++; 1502 fds++; 1503 ufds++; 1504 } 1505 td->td_retval[0] = n; 1506 return (0); 1507 } 1508 1509 static int 1510 pollscan(struct thread *td, struct pollfd *fds, u_int nfd) 1511 { 1512 struct filedesc *fdp = td->td_proc->p_fd; 1513 struct file *fp; 1514 int i, n = 0; 1515 1516 FILEDESC_SLOCK(fdp); 1517 for (i = 0; i < nfd; i++, fds++) { 1518 if (fds->fd > fdp->fd_lastfile) { 1519 fds->revents = POLLNVAL; 1520 n++; 1521 } else if (fds->fd < 0) { 1522 fds->revents = 0; 1523 } else { 1524 fp = fdp->fd_ofiles[fds->fd].fde_file; 1525 #ifdef CAPABILITIES 1526 if (fp == NULL || 1527 cap_check(cap_rights(fdp, fds->fd), &cap_event_rights) != 0) 1528 #else 1529 if (fp == NULL) 1530 #endif 1531 { 1532 fds->revents = POLLNVAL; 1533 n++; 1534 } else { 1535 /* 1536 * Note: backend also returns POLLHUP and 1537 * POLLERR if appropriate. 1538 */ 1539 selfdalloc(td, fds); 1540 fds->revents = fo_poll(fp, fds->events, 1541 td->td_ucred, td); 1542 /* 1543 * POSIX requires POLLOUT to be never 1544 * set simultaneously with POLLHUP. 1545 */ 1546 if ((fds->revents & POLLHUP) != 0) 1547 fds->revents &= ~POLLOUT; 1548 1549 if (fds->revents != 0) 1550 n++; 1551 } 1552 } 1553 } 1554 FILEDESC_SUNLOCK(fdp); 1555 td->td_retval[0] = n; 1556 return (0); 1557 } 1558 1559 /* 1560 * XXX This was created specifically to support netncp and netsmb. This 1561 * allows the caller to specify a socket to wait for events on. It returns 1562 * 0 if any events matched and an error otherwise. There is no way to 1563 * determine which events fired. 1564 */ 1565 int 1566 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1567 { 1568 struct timeval rtv; 1569 sbintime_t asbt, precision, rsbt; 1570 int error; 1571 1572 precision = 0; /* stupid gcc! */ 1573 if (tvp != NULL) { 1574 rtv = *tvp; 1575 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1576 rtv.tv_usec >= 1000000) 1577 return (EINVAL); 1578 if (!timevalisset(&rtv)) 1579 asbt = 0; 1580 else if (rtv.tv_sec <= INT32_MAX) { 1581 rsbt = tvtosbt(rtv); 1582 precision = rsbt; 1583 precision >>= tc_precexp; 1584 if (TIMESEL(&asbt, rsbt)) 1585 asbt += tc_tick_sbt; 1586 if (asbt <= SBT_MAX - rsbt) 1587 asbt += rsbt; 1588 else 1589 asbt = -1; 1590 } else 1591 asbt = -1; 1592 } else 1593 asbt = -1; 1594 seltdinit(td); 1595 /* 1596 * Iterate until the timeout expires or the socket becomes ready. 1597 */ 1598 for (;;) { 1599 selfdalloc(td, NULL); 1600 error = sopoll(so, events, NULL, td); 1601 /* error here is actually the ready events. */ 1602 if (error) 1603 return (0); 1604 error = seltdwait(td, asbt, precision); 1605 if (error) 1606 break; 1607 } 1608 seltdclear(td); 1609 /* XXX Duplicates ncp/smb behavior. */ 1610 if (error == ERESTART) 1611 error = 0; 1612 return (error); 1613 } 1614 1615 /* 1616 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1617 * have two select sets, one for read and another for write. 1618 */ 1619 static void 1620 selfdalloc(struct thread *td, void *cookie) 1621 { 1622 struct seltd *stp; 1623 1624 stp = td->td_sel; 1625 if (stp->st_free1 == NULL) 1626 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1627 stp->st_free1->sf_td = stp; 1628 stp->st_free1->sf_cookie = cookie; 1629 if (stp->st_free2 == NULL) 1630 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1631 stp->st_free2->sf_td = stp; 1632 stp->st_free2->sf_cookie = cookie; 1633 } 1634 1635 static void 1636 selfdfree(struct seltd *stp, struct selfd *sfp) 1637 { 1638 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1639 if (sfp->sf_si != NULL) { 1640 mtx_lock(sfp->sf_mtx); 1641 if (sfp->sf_si != NULL) { 1642 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1643 refcount_release(&sfp->sf_refs); 1644 } 1645 mtx_unlock(sfp->sf_mtx); 1646 } 1647 if (refcount_release(&sfp->sf_refs)) 1648 uma_zfree(selfd_zone, sfp); 1649 } 1650 1651 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1652 void 1653 seldrain(struct selinfo *sip) 1654 { 1655 1656 /* 1657 * This feature is already provided by doselwakeup(), thus it is 1658 * enough to go for it. 1659 * Eventually, the context, should take care to avoid races 1660 * between thread calling select()/poll() and file descriptor 1661 * detaching, but, again, the races are just the same as 1662 * selwakeup(). 1663 */ 1664 doselwakeup(sip, -1); 1665 } 1666 1667 /* 1668 * Record a select request. 1669 */ 1670 void 1671 selrecord(struct thread *selector, struct selinfo *sip) 1672 { 1673 struct selfd *sfp; 1674 struct seltd *stp; 1675 struct mtx *mtxp; 1676 1677 stp = selector->td_sel; 1678 /* 1679 * Don't record when doing a rescan. 1680 */ 1681 if (stp->st_flags & SELTD_RESCAN) 1682 return; 1683 /* 1684 * Grab one of the preallocated descriptors. 1685 */ 1686 sfp = NULL; 1687 if ((sfp = stp->st_free1) != NULL) 1688 stp->st_free1 = NULL; 1689 else if ((sfp = stp->st_free2) != NULL) 1690 stp->st_free2 = NULL; 1691 else 1692 panic("selrecord: No free selfd on selq"); 1693 mtxp = sip->si_mtx; 1694 if (mtxp == NULL) 1695 mtxp = mtx_pool_find(mtxpool_select, sip); 1696 /* 1697 * Initialize the sfp and queue it in the thread. 1698 */ 1699 sfp->sf_si = sip; 1700 sfp->sf_mtx = mtxp; 1701 refcount_init(&sfp->sf_refs, 2); 1702 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1703 /* 1704 * Now that we've locked the sip, check for initialization. 1705 */ 1706 mtx_lock(mtxp); 1707 if (sip->si_mtx == NULL) { 1708 sip->si_mtx = mtxp; 1709 TAILQ_INIT(&sip->si_tdlist); 1710 } 1711 /* 1712 * Add this thread to the list of selfds listening on this selinfo. 1713 */ 1714 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1715 mtx_unlock(sip->si_mtx); 1716 } 1717 1718 /* Wake up a selecting thread. */ 1719 void 1720 selwakeup(struct selinfo *sip) 1721 { 1722 doselwakeup(sip, -1); 1723 } 1724 1725 /* Wake up a selecting thread, and set its priority. */ 1726 void 1727 selwakeuppri(struct selinfo *sip, int pri) 1728 { 1729 doselwakeup(sip, pri); 1730 } 1731 1732 /* 1733 * Do a wakeup when a selectable event occurs. 1734 */ 1735 static void 1736 doselwakeup(struct selinfo *sip, int pri) 1737 { 1738 struct selfd *sfp; 1739 struct selfd *sfn; 1740 struct seltd *stp; 1741 1742 /* If it's not initialized there can't be any waiters. */ 1743 if (sip->si_mtx == NULL) 1744 return; 1745 /* 1746 * Locking the selinfo locks all selfds associated with it. 1747 */ 1748 mtx_lock(sip->si_mtx); 1749 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1750 /* 1751 * Once we remove this sfp from the list and clear the 1752 * sf_si seltdclear will know to ignore this si. 1753 */ 1754 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1755 sfp->sf_si = NULL; 1756 stp = sfp->sf_td; 1757 mtx_lock(&stp->st_mtx); 1758 stp->st_flags |= SELTD_PENDING; 1759 cv_broadcastpri(&stp->st_wait, pri); 1760 mtx_unlock(&stp->st_mtx); 1761 if (refcount_release(&sfp->sf_refs)) 1762 uma_zfree(selfd_zone, sfp); 1763 } 1764 mtx_unlock(sip->si_mtx); 1765 } 1766 1767 static void 1768 seltdinit(struct thread *td) 1769 { 1770 struct seltd *stp; 1771 1772 if ((stp = td->td_sel) != NULL) 1773 goto out; 1774 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1775 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1776 cv_init(&stp->st_wait, "select"); 1777 out: 1778 stp->st_flags = 0; 1779 STAILQ_INIT(&stp->st_selq); 1780 } 1781 1782 static int 1783 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1784 { 1785 struct seltd *stp; 1786 int error; 1787 1788 stp = td->td_sel; 1789 /* 1790 * An event of interest may occur while we do not hold the seltd 1791 * locked so check the pending flag before we sleep. 1792 */ 1793 mtx_lock(&stp->st_mtx); 1794 /* 1795 * Any further calls to selrecord will be a rescan. 1796 */ 1797 stp->st_flags |= SELTD_RESCAN; 1798 if (stp->st_flags & SELTD_PENDING) { 1799 mtx_unlock(&stp->st_mtx); 1800 return (0); 1801 } 1802 if (sbt == 0) 1803 error = EWOULDBLOCK; 1804 else if (sbt != -1) 1805 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 1806 sbt, precision, C_ABSOLUTE); 1807 else 1808 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1809 mtx_unlock(&stp->st_mtx); 1810 1811 return (error); 1812 } 1813 1814 void 1815 seltdfini(struct thread *td) 1816 { 1817 struct seltd *stp; 1818 1819 stp = td->td_sel; 1820 if (stp == NULL) 1821 return; 1822 if (stp->st_free1) 1823 uma_zfree(selfd_zone, stp->st_free1); 1824 if (stp->st_free2) 1825 uma_zfree(selfd_zone, stp->st_free2); 1826 td->td_sel = NULL; 1827 cv_destroy(&stp->st_wait); 1828 mtx_destroy(&stp->st_mtx); 1829 free(stp, M_SELECT); 1830 } 1831 1832 /* 1833 * Remove the references to the thread from all of the objects we were 1834 * polling. 1835 */ 1836 static void 1837 seltdclear(struct thread *td) 1838 { 1839 struct seltd *stp; 1840 struct selfd *sfp; 1841 struct selfd *sfn; 1842 1843 stp = td->td_sel; 1844 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1845 selfdfree(stp, sfp); 1846 stp->st_flags = 0; 1847 } 1848 1849 static void selectinit(void *); 1850 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1851 static void 1852 selectinit(void *dummy __unused) 1853 { 1854 1855 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, 1856 NULL, NULL, UMA_ALIGN_PTR, 0); 1857 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 1858 } 1859 1860 /* 1861 * Set up a syscall return value that follows the convention specified for 1862 * posix_* functions. 1863 */ 1864 int 1865 kern_posix_error(struct thread *td, int error) 1866 { 1867 1868 if (error <= 0) 1869 return (error); 1870 td->td_errno = error; 1871 td->td_pflags |= TDP_NERRNO; 1872 td->td_retval[0] = error; 1873 return (0); 1874 } 1875