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 }; 160 161 MALLOC_DEFINE(M_SELFD, "selfd", "selfd"); 162 static struct mtx_pool *mtxpool_select; 163 164 #ifdef __LP64__ 165 size_t 166 devfs_iosize_max(void) 167 { 168 169 return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 170 INT_MAX : SSIZE_MAX); 171 } 172 173 size_t 174 iosize_max(void) 175 { 176 177 return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 178 INT_MAX : SSIZE_MAX); 179 } 180 #endif 181 182 #ifndef _SYS_SYSPROTO_H_ 183 struct read_args { 184 int fd; 185 void *buf; 186 size_t nbyte; 187 }; 188 #endif 189 int 190 sys_read(struct thread *td, struct read_args *uap) 191 { 192 struct uio auio; 193 struct iovec aiov; 194 int error; 195 196 if (uap->nbyte > IOSIZE_MAX) 197 return (EINVAL); 198 aiov.iov_base = uap->buf; 199 aiov.iov_len = uap->nbyte; 200 auio.uio_iov = &aiov; 201 auio.uio_iovcnt = 1; 202 auio.uio_resid = uap->nbyte; 203 auio.uio_segflg = UIO_USERSPACE; 204 error = kern_readv(td, uap->fd, &auio); 205 return (error); 206 } 207 208 /* 209 * Positioned read system call 210 */ 211 #ifndef _SYS_SYSPROTO_H_ 212 struct pread_args { 213 int fd; 214 void *buf; 215 size_t nbyte; 216 int pad; 217 off_t offset; 218 }; 219 #endif 220 int 221 sys_pread(struct thread *td, struct pread_args *uap) 222 { 223 224 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 225 } 226 227 int 228 kern_pread(struct thread *td, int fd, void *buf, size_t nbyte, off_t offset) 229 { 230 struct uio auio; 231 struct iovec aiov; 232 int error; 233 234 if (nbyte > IOSIZE_MAX) 235 return (EINVAL); 236 aiov.iov_base = buf; 237 aiov.iov_len = nbyte; 238 auio.uio_iov = &aiov; 239 auio.uio_iovcnt = 1; 240 auio.uio_resid = nbyte; 241 auio.uio_segflg = UIO_USERSPACE; 242 error = kern_preadv(td, fd, &auio, offset); 243 return (error); 244 } 245 246 #if defined(COMPAT_FREEBSD6) 247 int 248 freebsd6_pread(struct thread *td, struct freebsd6_pread_args *uap) 249 { 250 251 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 252 } 253 #endif 254 255 /* 256 * Scatter read system call. 257 */ 258 #ifndef _SYS_SYSPROTO_H_ 259 struct readv_args { 260 int fd; 261 struct iovec *iovp; 262 u_int iovcnt; 263 }; 264 #endif 265 int 266 sys_readv(struct thread *td, struct readv_args *uap) 267 { 268 struct uio *auio; 269 int error; 270 271 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 272 if (error) 273 return (error); 274 error = kern_readv(td, uap->fd, auio); 275 free(auio, M_IOV); 276 return (error); 277 } 278 279 int 280 kern_readv(struct thread *td, int fd, struct uio *auio) 281 { 282 struct file *fp; 283 int error; 284 285 error = fget_read(td, fd, &cap_read_rights, &fp); 286 if (error) 287 return (error); 288 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 289 fdrop(fp, td); 290 return (error); 291 } 292 293 /* 294 * Scatter positioned read system call. 295 */ 296 #ifndef _SYS_SYSPROTO_H_ 297 struct preadv_args { 298 int fd; 299 struct iovec *iovp; 300 u_int iovcnt; 301 off_t offset; 302 }; 303 #endif 304 int 305 sys_preadv(struct thread *td, struct preadv_args *uap) 306 { 307 struct uio *auio; 308 int error; 309 310 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 311 if (error) 312 return (error); 313 error = kern_preadv(td, uap->fd, auio, uap->offset); 314 free(auio, M_IOV); 315 return (error); 316 } 317 318 int 319 kern_preadv(struct thread *td, int fd, struct uio *auio, off_t offset) 320 { 321 struct file *fp; 322 int error; 323 324 error = fget_read(td, fd, &cap_pread_rights, &fp); 325 if (error) 326 return (error); 327 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 328 error = ESPIPE; 329 else if (offset < 0 && 330 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 331 error = EINVAL; 332 else 333 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 334 fdrop(fp, td); 335 return (error); 336 } 337 338 /* 339 * Common code for readv and preadv that reads data in 340 * from a file using the passed in uio, offset, and flags. 341 */ 342 static int 343 dofileread(struct thread *td, int fd, struct file *fp, struct uio *auio, 344 off_t offset, int flags) 345 { 346 ssize_t cnt; 347 int error; 348 #ifdef KTRACE 349 struct uio *ktruio = NULL; 350 #endif 351 352 AUDIT_ARG_FD(fd); 353 354 /* Finish zero length reads right here */ 355 if (auio->uio_resid == 0) { 356 td->td_retval[0] = 0; 357 return (0); 358 } 359 auio->uio_rw = UIO_READ; 360 auio->uio_offset = offset; 361 auio->uio_td = td; 362 #ifdef KTRACE 363 if (KTRPOINT(td, KTR_GENIO)) 364 ktruio = cloneuio(auio); 365 #endif 366 cnt = auio->uio_resid; 367 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 368 if (auio->uio_resid != cnt && (error == ERESTART || 369 error == EINTR || error == EWOULDBLOCK)) 370 error = 0; 371 } 372 cnt -= auio->uio_resid; 373 #ifdef KTRACE 374 if (ktruio != NULL) { 375 ktruio->uio_resid = cnt; 376 ktrgenio(fd, UIO_READ, ktruio, error); 377 } 378 #endif 379 td->td_retval[0] = cnt; 380 return (error); 381 } 382 383 #ifndef _SYS_SYSPROTO_H_ 384 struct write_args { 385 int fd; 386 const void *buf; 387 size_t nbyte; 388 }; 389 #endif 390 int 391 sys_write(struct thread *td, struct write_args *uap) 392 { 393 struct uio auio; 394 struct iovec aiov; 395 int error; 396 397 if (uap->nbyte > IOSIZE_MAX) 398 return (EINVAL); 399 aiov.iov_base = (void *)(uintptr_t)uap->buf; 400 aiov.iov_len = uap->nbyte; 401 auio.uio_iov = &aiov; 402 auio.uio_iovcnt = 1; 403 auio.uio_resid = uap->nbyte; 404 auio.uio_segflg = UIO_USERSPACE; 405 error = kern_writev(td, uap->fd, &auio); 406 return (error); 407 } 408 409 /* 410 * Positioned write system call. 411 */ 412 #ifndef _SYS_SYSPROTO_H_ 413 struct pwrite_args { 414 int fd; 415 const void *buf; 416 size_t nbyte; 417 int pad; 418 off_t offset; 419 }; 420 #endif 421 int 422 sys_pwrite(struct thread *td, struct pwrite_args *uap) 423 { 424 425 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 426 } 427 428 int 429 kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte, 430 off_t offset) 431 { 432 struct uio auio; 433 struct iovec aiov; 434 int error; 435 436 if (nbyte > IOSIZE_MAX) 437 return (EINVAL); 438 aiov.iov_base = (void *)(uintptr_t)buf; 439 aiov.iov_len = nbyte; 440 auio.uio_iov = &aiov; 441 auio.uio_iovcnt = 1; 442 auio.uio_resid = nbyte; 443 auio.uio_segflg = UIO_USERSPACE; 444 error = kern_pwritev(td, fd, &auio, offset); 445 return (error); 446 } 447 448 #if defined(COMPAT_FREEBSD6) 449 int 450 freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap) 451 { 452 453 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 454 } 455 #endif 456 457 /* 458 * Gather write system call. 459 */ 460 #ifndef _SYS_SYSPROTO_H_ 461 struct writev_args { 462 int fd; 463 struct iovec *iovp; 464 u_int iovcnt; 465 }; 466 #endif 467 int 468 sys_writev(struct thread *td, struct writev_args *uap) 469 { 470 struct uio *auio; 471 int error; 472 473 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 474 if (error) 475 return (error); 476 error = kern_writev(td, uap->fd, auio); 477 free(auio, M_IOV); 478 return (error); 479 } 480 481 int 482 kern_writev(struct thread *td, int fd, struct uio *auio) 483 { 484 struct file *fp; 485 int error; 486 487 error = fget_write(td, fd, &cap_write_rights, &fp); 488 if (error) 489 return (error); 490 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 491 fdrop(fp, td); 492 return (error); 493 } 494 495 /* 496 * Gather positioned write system call. 497 */ 498 #ifndef _SYS_SYSPROTO_H_ 499 struct pwritev_args { 500 int fd; 501 struct iovec *iovp; 502 u_int iovcnt; 503 off_t offset; 504 }; 505 #endif 506 int 507 sys_pwritev(struct thread *td, struct pwritev_args *uap) 508 { 509 struct uio *auio; 510 int error; 511 512 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 513 if (error) 514 return (error); 515 error = kern_pwritev(td, uap->fd, auio, uap->offset); 516 free(auio, M_IOV); 517 return (error); 518 } 519 520 int 521 kern_pwritev(struct thread *td, int fd, struct uio *auio, off_t offset) 522 { 523 struct file *fp; 524 int error; 525 526 error = fget_write(td, fd, &cap_pwrite_rights, &fp); 527 if (error) 528 return (error); 529 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 530 error = ESPIPE; 531 else if (offset < 0 && 532 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 533 error = EINVAL; 534 else 535 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 536 fdrop(fp, td); 537 return (error); 538 } 539 540 /* 541 * Common code for writev and pwritev that writes data to 542 * a file using the passed in uio, offset, and flags. 543 */ 544 static int 545 dofilewrite(struct thread *td, int fd, struct file *fp, struct uio *auio, 546 off_t offset, int flags) 547 { 548 ssize_t cnt; 549 int error; 550 #ifdef KTRACE 551 struct uio *ktruio = NULL; 552 #endif 553 554 AUDIT_ARG_FD(fd); 555 auio->uio_rw = UIO_WRITE; 556 auio->uio_td = td; 557 auio->uio_offset = offset; 558 #ifdef KTRACE 559 if (KTRPOINT(td, KTR_GENIO)) 560 ktruio = cloneuio(auio); 561 #endif 562 cnt = auio->uio_resid; 563 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 564 if (auio->uio_resid != cnt && (error == ERESTART || 565 error == EINTR || error == EWOULDBLOCK)) 566 error = 0; 567 /* Socket layer is responsible for issuing SIGPIPE. */ 568 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 569 PROC_LOCK(td->td_proc); 570 tdsignal(td, SIGPIPE); 571 PROC_UNLOCK(td->td_proc); 572 } 573 } 574 cnt -= auio->uio_resid; 575 #ifdef KTRACE 576 if (ktruio != NULL) { 577 ktruio->uio_resid = cnt; 578 ktrgenio(fd, UIO_WRITE, ktruio, error); 579 } 580 #endif 581 td->td_retval[0] = cnt; 582 return (error); 583 } 584 585 /* 586 * Truncate a file given a file descriptor. 587 * 588 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 589 * descriptor isn't writable. 590 */ 591 int 592 kern_ftruncate(struct thread *td, int fd, off_t length) 593 { 594 struct file *fp; 595 int error; 596 597 AUDIT_ARG_FD(fd); 598 if (length < 0) 599 return (EINVAL); 600 error = fget(td, fd, &cap_ftruncate_rights, &fp); 601 if (error) 602 return (error); 603 AUDIT_ARG_FILE(td->td_proc, fp); 604 if (!(fp->f_flag & FWRITE)) { 605 fdrop(fp, td); 606 return (EINVAL); 607 } 608 error = fo_truncate(fp, length, td->td_ucred, td); 609 fdrop(fp, td); 610 return (error); 611 } 612 613 #ifndef _SYS_SYSPROTO_H_ 614 struct ftruncate_args { 615 int fd; 616 int pad; 617 off_t length; 618 }; 619 #endif 620 int 621 sys_ftruncate(struct thread *td, struct ftruncate_args *uap) 622 { 623 624 return (kern_ftruncate(td, uap->fd, uap->length)); 625 } 626 627 #if defined(COMPAT_43) 628 #ifndef _SYS_SYSPROTO_H_ 629 struct oftruncate_args { 630 int fd; 631 long length; 632 }; 633 #endif 634 int 635 oftruncate(struct thread *td, struct oftruncate_args *uap) 636 { 637 638 return (kern_ftruncate(td, uap->fd, uap->length)); 639 } 640 #endif /* COMPAT_43 */ 641 642 #ifndef _SYS_SYSPROTO_H_ 643 struct ioctl_args { 644 int fd; 645 u_long com; 646 caddr_t data; 647 }; 648 #endif 649 /* ARGSUSED */ 650 int 651 sys_ioctl(struct thread *td, struct ioctl_args *uap) 652 { 653 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); 654 uint32_t com; 655 int arg, error; 656 u_int size; 657 caddr_t data; 658 659 #ifdef INVARIANTS 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 } 665 #endif 666 com = (uint32_t)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 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap) 823 { 824 int error; 825 826 error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len); 827 return (kern_posix_error(td, error)); 828 } 829 830 int 831 kern_posix_fallocate(struct thread *td, int fd, off_t offset, off_t len) 832 { 833 struct file *fp; 834 int error; 835 836 AUDIT_ARG_FD(fd); 837 if (offset < 0 || len <= 0) 838 return (EINVAL); 839 /* Check for wrap. */ 840 if (offset > OFF_MAX - len) 841 return (EFBIG); 842 AUDIT_ARG_FD(fd); 843 error = fget(td, fd, &cap_pwrite_rights, &fp); 844 if (error != 0) 845 return (error); 846 AUDIT_ARG_FILE(td->td_proc, fp); 847 if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) { 848 error = ESPIPE; 849 goto out; 850 } 851 if ((fp->f_flag & FWRITE) == 0) { 852 error = EBADF; 853 goto out; 854 } 855 856 error = fo_fallocate(fp, offset, len, td); 857 out: 858 fdrop(fp, td); 859 return (error); 860 } 861 862 int 863 poll_no_poll(int events) 864 { 865 /* 866 * Return true for read/write. If the user asked for something 867 * special, return POLLNVAL, so that clients have a way of 868 * determining reliably whether or not the extended 869 * functionality is present without hard-coding knowledge 870 * of specific filesystem implementations. 871 */ 872 if (events & ~POLLSTANDARD) 873 return (POLLNVAL); 874 875 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 876 } 877 878 int 879 sys_pselect(struct thread *td, struct pselect_args *uap) 880 { 881 struct timespec ts; 882 struct timeval tv, *tvp; 883 sigset_t set, *uset; 884 int error; 885 886 if (uap->ts != NULL) { 887 error = copyin(uap->ts, &ts, sizeof(ts)); 888 if (error != 0) 889 return (error); 890 TIMESPEC_TO_TIMEVAL(&tv, &ts); 891 tvp = &tv; 892 } else 893 tvp = NULL; 894 if (uap->sm != NULL) { 895 error = copyin(uap->sm, &set, sizeof(set)); 896 if (error != 0) 897 return (error); 898 uset = &set; 899 } else 900 uset = NULL; 901 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 902 uset, NFDBITS)); 903 } 904 905 int 906 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 907 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 908 { 909 int error; 910 911 if (uset != NULL) { 912 error = kern_sigprocmask(td, SIG_SETMASK, uset, 913 &td->td_oldsigmask, 0); 914 if (error != 0) 915 return (error); 916 td->td_pflags |= TDP_OLDMASK; 917 /* 918 * Make sure that ast() is called on return to 919 * usermode and TDP_OLDMASK is cleared, restoring old 920 * sigmask. 921 */ 922 thread_lock(td); 923 td->td_flags |= TDF_ASTPENDING; 924 thread_unlock(td); 925 } 926 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 927 return (error); 928 } 929 930 #ifndef _SYS_SYSPROTO_H_ 931 struct select_args { 932 int nd; 933 fd_set *in, *ou, *ex; 934 struct timeval *tv; 935 }; 936 #endif 937 int 938 sys_select(struct thread *td, struct select_args *uap) 939 { 940 struct timeval tv, *tvp; 941 int error; 942 943 if (uap->tv != NULL) { 944 error = copyin(uap->tv, &tv, sizeof(tv)); 945 if (error) 946 return (error); 947 tvp = &tv; 948 } else 949 tvp = NULL; 950 951 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 952 NFDBITS)); 953 } 954 955 /* 956 * In the unlikely case when user specified n greater then the last 957 * open file descriptor, check that no bits are set after the last 958 * valid fd. We must return EBADF if any is set. 959 * 960 * There are applications that rely on the behaviour. 961 * 962 * nd is fd_nfiles. 963 */ 964 static int 965 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 966 { 967 char *addr, *oaddr; 968 int b, i, res; 969 uint8_t bits; 970 971 if (nd >= ndu || fd_in == NULL) 972 return (0); 973 974 oaddr = NULL; 975 bits = 0; /* silence gcc */ 976 for (i = nd; i < ndu; i++) { 977 b = i / NBBY; 978 #if BYTE_ORDER == LITTLE_ENDIAN 979 addr = (char *)fd_in + b; 980 #else 981 addr = (char *)fd_in; 982 if (abi_nfdbits == NFDBITS) { 983 addr += rounddown(b, sizeof(fd_mask)) + 984 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 985 } else { 986 addr += rounddown(b, sizeof(uint32_t)) + 987 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 988 } 989 #endif 990 if (addr != oaddr) { 991 res = fubyte(addr); 992 if (res == -1) 993 return (EFAULT); 994 oaddr = addr; 995 bits = res; 996 } 997 if ((bits & (1 << (i % NBBY))) != 0) 998 return (EBADF); 999 } 1000 return (0); 1001 } 1002 1003 int 1004 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 1005 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 1006 { 1007 struct filedesc *fdp; 1008 /* 1009 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 1010 * infds with the new FD_SETSIZE of 1024, and more than enough for 1011 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 1012 * of 256. 1013 */ 1014 fd_mask s_selbits[howmany(2048, NFDBITS)]; 1015 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 1016 struct timeval rtv; 1017 sbintime_t asbt, precision, rsbt; 1018 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 1019 int error, lf, ndu; 1020 1021 if (nd < 0) 1022 return (EINVAL); 1023 fdp = td->td_proc->p_fd; 1024 ndu = nd; 1025 lf = fdp->fd_nfiles; 1026 if (nd > lf) 1027 nd = lf; 1028 1029 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 1030 if (error != 0) 1031 return (error); 1032 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 1033 if (error != 0) 1034 return (error); 1035 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 1036 if (error != 0) 1037 return (error); 1038 1039 /* 1040 * Allocate just enough bits for the non-null fd_sets. Use the 1041 * preallocated auto buffer if possible. 1042 */ 1043 nfdbits = roundup(nd, NFDBITS); 1044 ncpbytes = nfdbits / NBBY; 1045 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 1046 nbufbytes = 0; 1047 if (fd_in != NULL) 1048 nbufbytes += 2 * ncpbytes; 1049 if (fd_ou != NULL) 1050 nbufbytes += 2 * ncpbytes; 1051 if (fd_ex != NULL) 1052 nbufbytes += 2 * ncpbytes; 1053 if (nbufbytes <= sizeof s_selbits) 1054 selbits = &s_selbits[0]; 1055 else 1056 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1057 1058 /* 1059 * Assign pointers into the bit buffers and fetch the input bits. 1060 * Put the output buffers together so that they can be bzeroed 1061 * together. 1062 */ 1063 sbp = selbits; 1064 #define getbits(name, x) \ 1065 do { \ 1066 if (name == NULL) { \ 1067 ibits[x] = NULL; \ 1068 obits[x] = NULL; \ 1069 } else { \ 1070 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1071 obits[x] = sbp; \ 1072 sbp += ncpbytes / sizeof *sbp; \ 1073 error = copyin(name, ibits[x], ncpubytes); \ 1074 if (error != 0) \ 1075 goto done; \ 1076 if (ncpbytes != ncpubytes) \ 1077 bzero((char *)ibits[x] + ncpubytes, \ 1078 ncpbytes - ncpubytes); \ 1079 } \ 1080 } while (0) 1081 getbits(fd_in, 0); 1082 getbits(fd_ou, 1); 1083 getbits(fd_ex, 2); 1084 #undef getbits 1085 1086 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1087 /* 1088 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1089 * we are running under 32-bit emulation. This should be more 1090 * generic. 1091 */ 1092 #define swizzle_fdset(bits) \ 1093 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1094 int i; \ 1095 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1096 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1097 } 1098 #else 1099 #define swizzle_fdset(bits) 1100 #endif 1101 1102 /* Make sure the bit order makes it through an ABI transition */ 1103 swizzle_fdset(ibits[0]); 1104 swizzle_fdset(ibits[1]); 1105 swizzle_fdset(ibits[2]); 1106 1107 if (nbufbytes != 0) 1108 bzero(selbits, nbufbytes / 2); 1109 1110 precision = 0; 1111 if (tvp != NULL) { 1112 rtv = *tvp; 1113 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1114 rtv.tv_usec >= 1000000) { 1115 error = EINVAL; 1116 goto done; 1117 } 1118 if (!timevalisset(&rtv)) 1119 asbt = 0; 1120 else if (rtv.tv_sec <= INT32_MAX) { 1121 rsbt = tvtosbt(rtv); 1122 precision = rsbt; 1123 precision >>= tc_precexp; 1124 if (TIMESEL(&asbt, rsbt)) 1125 asbt += tc_tick_sbt; 1126 if (asbt <= SBT_MAX - rsbt) 1127 asbt += rsbt; 1128 else 1129 asbt = -1; 1130 } else 1131 asbt = -1; 1132 } else 1133 asbt = -1; 1134 seltdinit(td); 1135 /* Iterate until the timeout expires or descriptors become ready. */ 1136 for (;;) { 1137 error = selscan(td, ibits, obits, nd); 1138 if (error || td->td_retval[0] != 0) 1139 break; 1140 error = seltdwait(td, asbt, precision); 1141 if (error) 1142 break; 1143 error = selrescan(td, ibits, obits); 1144 if (error || td->td_retval[0] != 0) 1145 break; 1146 } 1147 seltdclear(td); 1148 1149 done: 1150 /* select is not restarted after signals... */ 1151 if (error == ERESTART) 1152 error = EINTR; 1153 if (error == EWOULDBLOCK) 1154 error = 0; 1155 1156 /* swizzle bit order back, if necessary */ 1157 swizzle_fdset(obits[0]); 1158 swizzle_fdset(obits[1]); 1159 swizzle_fdset(obits[2]); 1160 #undef swizzle_fdset 1161 1162 #define putbits(name, x) \ 1163 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1164 error = error2; 1165 if (error == 0) { 1166 int error2; 1167 1168 putbits(fd_in, 0); 1169 putbits(fd_ou, 1); 1170 putbits(fd_ex, 2); 1171 #undef putbits 1172 } 1173 if (selbits != &s_selbits[0]) 1174 free(selbits, M_SELECT); 1175 1176 return (error); 1177 } 1178 /* 1179 * Convert a select bit set to poll flags. 1180 * 1181 * The backend always returns POLLHUP/POLLERR if appropriate and we 1182 * return this as a set bit in any set. 1183 */ 1184 static int select_flags[3] = { 1185 POLLRDNORM | POLLHUP | POLLERR, 1186 POLLWRNORM | POLLHUP | POLLERR, 1187 POLLRDBAND | POLLERR 1188 }; 1189 1190 /* 1191 * Compute the fo_poll flags required for a fd given by the index and 1192 * bit position in the fd_mask array. 1193 */ 1194 static __inline int 1195 selflags(fd_mask **ibits, int idx, fd_mask bit) 1196 { 1197 int flags; 1198 int msk; 1199 1200 flags = 0; 1201 for (msk = 0; msk < 3; msk++) { 1202 if (ibits[msk] == NULL) 1203 continue; 1204 if ((ibits[msk][idx] & bit) == 0) 1205 continue; 1206 flags |= select_flags[msk]; 1207 } 1208 return (flags); 1209 } 1210 1211 /* 1212 * Set the appropriate output bits given a mask of fired events and the 1213 * input bits originally requested. 1214 */ 1215 static __inline int 1216 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1217 { 1218 int msk; 1219 int n; 1220 1221 n = 0; 1222 for (msk = 0; msk < 3; msk++) { 1223 if ((events & select_flags[msk]) == 0) 1224 continue; 1225 if (ibits[msk] == NULL) 1226 continue; 1227 if ((ibits[msk][idx] & bit) == 0) 1228 continue; 1229 /* 1230 * XXX Check for a duplicate set. This can occur because a 1231 * socket calls selrecord() twice for each poll() call 1232 * resulting in two selfds per real fd. selrescan() will 1233 * call selsetbits twice as a result. 1234 */ 1235 if ((obits[msk][idx] & bit) != 0) 1236 continue; 1237 obits[msk][idx] |= bit; 1238 n++; 1239 } 1240 1241 return (n); 1242 } 1243 1244 static __inline int 1245 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) 1246 { 1247 1248 return (fget_unlocked(fdp, fd, &cap_event_rights, fpp)); 1249 } 1250 1251 /* 1252 * Traverse the list of fds attached to this thread's seltd and check for 1253 * completion. 1254 */ 1255 static int 1256 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1257 { 1258 struct filedesc *fdp; 1259 struct selinfo *si; 1260 struct seltd *stp; 1261 struct selfd *sfp; 1262 struct selfd *sfn; 1263 struct file *fp; 1264 fd_mask bit; 1265 int fd, ev, n, idx; 1266 int error; 1267 1268 fdp = td->td_proc->p_fd; 1269 stp = td->td_sel; 1270 n = 0; 1271 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1272 fd = (int)(uintptr_t)sfp->sf_cookie; 1273 si = sfp->sf_si; 1274 selfdfree(stp, sfp); 1275 /* If the selinfo wasn't cleared the event didn't fire. */ 1276 if (si != NULL) 1277 continue; 1278 error = getselfd_cap(fdp, fd, &fp); 1279 if (error) 1280 return (error); 1281 idx = fd / NFDBITS; 1282 bit = (fd_mask)1 << (fd % NFDBITS); 1283 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1284 fdrop(fp, td); 1285 if (ev != 0) 1286 n += selsetbits(ibits, obits, idx, bit, ev); 1287 } 1288 stp->st_flags = 0; 1289 td->td_retval[0] = n; 1290 return (0); 1291 } 1292 1293 /* 1294 * Perform the initial filedescriptor scan and register ourselves with 1295 * each selinfo. 1296 */ 1297 static int 1298 selscan(struct thread *td, fd_mask **ibits, fd_mask **obits, 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 *ufds, u_int nfds, 1350 struct timespec *tsp, sigset_t *uset) 1351 { 1352 struct pollfd *kfds; 1353 struct pollfd stackfds[32]; 1354 sbintime_t sbt, precision, tmp; 1355 time_t over; 1356 struct timespec ts; 1357 int error; 1358 1359 precision = 0; 1360 if (tsp != NULL) { 1361 if (tsp->tv_sec < 0) 1362 return (EINVAL); 1363 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000) 1364 return (EINVAL); 1365 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1366 sbt = 0; 1367 else { 1368 ts = *tsp; 1369 if (ts.tv_sec > INT32_MAX / 2) { 1370 over = ts.tv_sec - INT32_MAX / 2; 1371 ts.tv_sec -= over; 1372 } else 1373 over = 0; 1374 tmp = tstosbt(ts); 1375 precision = tmp; 1376 precision >>= tc_precexp; 1377 if (TIMESEL(&sbt, tmp)) 1378 sbt += tc_tick_sbt; 1379 sbt += tmp; 1380 } 1381 } else 1382 sbt = -1; 1383 1384 /* 1385 * This is kinda bogus. We have fd limits, but that is not 1386 * really related to the size of the pollfd array. Make sure 1387 * we let the process use at least FD_SETSIZE entries and at 1388 * least enough for the system-wide limits. We want to be reasonably 1389 * safe, but not overly restrictive. 1390 */ 1391 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1392 return (EINVAL); 1393 if (nfds > nitems(stackfds)) 1394 kfds = mallocarray(nfds, sizeof(*kfds), M_TEMP, M_WAITOK); 1395 else 1396 kfds = stackfds; 1397 error = copyin(ufds, kfds, nfds * sizeof(*kfds)); 1398 if (error) 1399 goto done; 1400 1401 if (uset != NULL) { 1402 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1403 &td->td_oldsigmask, 0); 1404 if (error) 1405 goto done; 1406 td->td_pflags |= TDP_OLDMASK; 1407 /* 1408 * Make sure that ast() is called on return to 1409 * usermode and TDP_OLDMASK is cleared, restoring old 1410 * sigmask. 1411 */ 1412 thread_lock(td); 1413 td->td_flags |= TDF_ASTPENDING; 1414 thread_unlock(td); 1415 } 1416 1417 seltdinit(td); 1418 /* Iterate until the timeout expires or descriptors become ready. */ 1419 for (;;) { 1420 error = pollscan(td, kfds, nfds); 1421 if (error || td->td_retval[0] != 0) 1422 break; 1423 error = seltdwait(td, sbt, precision); 1424 if (error) 1425 break; 1426 error = pollrescan(td); 1427 if (error || td->td_retval[0] != 0) 1428 break; 1429 } 1430 seltdclear(td); 1431 1432 done: 1433 /* poll is not restarted after signals... */ 1434 if (error == ERESTART) 1435 error = EINTR; 1436 if (error == EWOULDBLOCK) 1437 error = 0; 1438 if (error == 0) { 1439 error = pollout(td, kfds, ufds, nfds); 1440 if (error) 1441 goto out; 1442 } 1443 out: 1444 if (nfds > nitems(stackfds)) 1445 free(kfds, M_TEMP); 1446 return (error); 1447 } 1448 1449 int 1450 sys_ppoll(struct thread *td, struct ppoll_args *uap) 1451 { 1452 struct timespec ts, *tsp; 1453 sigset_t set, *ssp; 1454 int error; 1455 1456 if (uap->ts != NULL) { 1457 error = copyin(uap->ts, &ts, sizeof(ts)); 1458 if (error) 1459 return (error); 1460 tsp = &ts; 1461 } else 1462 tsp = NULL; 1463 if (uap->set != NULL) { 1464 error = copyin(uap->set, &set, sizeof(set)); 1465 if (error) 1466 return (error); 1467 ssp = &set; 1468 } else 1469 ssp = NULL; 1470 /* 1471 * fds is still a pointer to user space. kern_poll() will 1472 * take care of copyin that array to the kernel space. 1473 */ 1474 1475 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); 1476 } 1477 1478 #ifdef CAPABILITIES 1479 static int 1480 poll_fget(struct filedesc *fdp, int fd, struct file **fpp) 1481 { 1482 const struct filedescent *fde; 1483 const struct fdescenttbl *fdt; 1484 const cap_rights_t *haverights; 1485 struct file *fp; 1486 int error; 1487 1488 if (__predict_false(fd >= fdp->fd_nfiles)) 1489 return (EBADF); 1490 1491 fdt = fdp->fd_files; 1492 fde = &fdt->fdt_ofiles[fd]; 1493 fp = fde->fde_file; 1494 if (__predict_false(fp == NULL)) 1495 return (EBADF); 1496 haverights = cap_rights_fde_inline(fde); 1497 error = cap_check_inline(haverights, &cap_event_rights); 1498 if (__predict_false(error != 0)) 1499 return (EBADF); 1500 *fpp = fp; 1501 return (0); 1502 } 1503 #else 1504 static int 1505 poll_fget(struct filedesc *fdp, int fd, struct file **fpp) 1506 { 1507 struct file *fp; 1508 1509 if (__predict_false(fd >= fdp->fd_nfiles)) 1510 return (EBADF); 1511 1512 fp = fdp->fd_ofiles[fd].fde_file; 1513 if (__predict_false(fp == NULL)) 1514 return (EBADF); 1515 1516 *fpp = fp; 1517 return (0); 1518 } 1519 #endif 1520 1521 static int 1522 pollrescan(struct thread *td) 1523 { 1524 struct seltd *stp; 1525 struct selfd *sfp; 1526 struct selfd *sfn; 1527 struct selinfo *si; 1528 struct filedesc *fdp; 1529 struct file *fp; 1530 struct pollfd *fd; 1531 int n; 1532 1533 n = 0; 1534 fdp = td->td_proc->p_fd; 1535 stp = td->td_sel; 1536 FILEDESC_SLOCK(fdp); 1537 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1538 fd = (struct pollfd *)sfp->sf_cookie; 1539 si = sfp->sf_si; 1540 selfdfree(stp, sfp); 1541 /* If the selinfo wasn't cleared the event didn't fire. */ 1542 if (si != NULL) 1543 continue; 1544 if (poll_fget(fdp, fd->fd, &fp) != 0) { 1545 fd->revents = POLLNVAL; 1546 n++; 1547 continue; 1548 } 1549 /* 1550 * Note: backend also returns POLLHUP and 1551 * POLLERR if appropriate. 1552 */ 1553 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1554 if (fd->revents != 0) 1555 n++; 1556 } 1557 FILEDESC_SUNLOCK(fdp); 1558 stp->st_flags = 0; 1559 td->td_retval[0] = n; 1560 return (0); 1561 } 1562 1563 static int 1564 pollout(struct thread *td, struct pollfd *fds, struct pollfd *ufds, u_int nfd) 1565 { 1566 int error = 0; 1567 u_int i = 0; 1568 u_int n = 0; 1569 1570 for (i = 0; i < nfd; i++) { 1571 error = copyout(&fds->revents, &ufds->revents, 1572 sizeof(ufds->revents)); 1573 if (error) 1574 return (error); 1575 if (fds->revents != 0) 1576 n++; 1577 fds++; 1578 ufds++; 1579 } 1580 td->td_retval[0] = n; 1581 return (0); 1582 } 1583 1584 static int 1585 pollscan(struct thread *td, struct pollfd *fds, u_int nfd) 1586 { 1587 struct filedesc *fdp; 1588 struct file *fp; 1589 int i, n; 1590 1591 n = 0; 1592 fdp = td->td_proc->p_fd; 1593 FILEDESC_SLOCK(fdp); 1594 for (i = 0; i < nfd; i++, fds++) { 1595 if (fds->fd < 0) { 1596 fds->revents = 0; 1597 continue; 1598 } 1599 if (poll_fget(fdp, fds->fd, &fp) != 0) { 1600 fds->revents = POLLNVAL; 1601 n++; 1602 continue; 1603 } 1604 /* 1605 * Note: backend also returns POLLHUP and 1606 * POLLERR if appropriate. 1607 */ 1608 selfdalloc(td, fds); 1609 fds->revents = fo_poll(fp, fds->events, 1610 td->td_ucred, td); 1611 /* 1612 * POSIX requires POLLOUT to be never 1613 * set simultaneously with POLLHUP. 1614 */ 1615 if ((fds->revents & POLLHUP) != 0) 1616 fds->revents &= ~POLLOUT; 1617 1618 if (fds->revents != 0) 1619 n++; 1620 } 1621 FILEDESC_SUNLOCK(fdp); 1622 td->td_retval[0] = n; 1623 return (0); 1624 } 1625 1626 /* 1627 * XXX This was created specifically to support netncp and netsmb. This 1628 * allows the caller to specify a socket to wait for events on. It returns 1629 * 0 if any events matched and an error otherwise. There is no way to 1630 * determine which events fired. 1631 */ 1632 int 1633 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1634 { 1635 struct timeval rtv; 1636 sbintime_t asbt, precision, rsbt; 1637 int error; 1638 1639 precision = 0; /* stupid gcc! */ 1640 if (tvp != NULL) { 1641 rtv = *tvp; 1642 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1643 rtv.tv_usec >= 1000000) 1644 return (EINVAL); 1645 if (!timevalisset(&rtv)) 1646 asbt = 0; 1647 else if (rtv.tv_sec <= INT32_MAX) { 1648 rsbt = tvtosbt(rtv); 1649 precision = rsbt; 1650 precision >>= tc_precexp; 1651 if (TIMESEL(&asbt, rsbt)) 1652 asbt += tc_tick_sbt; 1653 if (asbt <= SBT_MAX - rsbt) 1654 asbt += rsbt; 1655 else 1656 asbt = -1; 1657 } else 1658 asbt = -1; 1659 } else 1660 asbt = -1; 1661 seltdinit(td); 1662 /* 1663 * Iterate until the timeout expires or the socket becomes ready. 1664 */ 1665 for (;;) { 1666 selfdalloc(td, NULL); 1667 error = sopoll(so, events, NULL, td); 1668 /* error here is actually the ready events. */ 1669 if (error) 1670 return (0); 1671 error = seltdwait(td, asbt, precision); 1672 if (error) 1673 break; 1674 } 1675 seltdclear(td); 1676 /* XXX Duplicates ncp/smb behavior. */ 1677 if (error == ERESTART) 1678 error = 0; 1679 return (error); 1680 } 1681 1682 /* 1683 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1684 * have two select sets, one for read and another for write. 1685 */ 1686 static void 1687 selfdalloc(struct thread *td, void *cookie) 1688 { 1689 struct seltd *stp; 1690 1691 stp = td->td_sel; 1692 if (stp->st_free1 == NULL) 1693 stp->st_free1 = malloc(sizeof(*stp->st_free1), M_SELFD, M_WAITOK|M_ZERO); 1694 stp->st_free1->sf_td = stp; 1695 stp->st_free1->sf_cookie = cookie; 1696 if (stp->st_free2 == NULL) 1697 stp->st_free2 = malloc(sizeof(*stp->st_free2), M_SELFD, M_WAITOK|M_ZERO); 1698 stp->st_free2->sf_td = stp; 1699 stp->st_free2->sf_cookie = cookie; 1700 } 1701 1702 static void 1703 selfdfree(struct seltd *stp, struct selfd *sfp) 1704 { 1705 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1706 /* 1707 * Paired with doselwakeup. 1708 */ 1709 if (atomic_load_acq_ptr((uintptr_t *)&sfp->sf_si) != (uintptr_t)NULL) { 1710 mtx_lock(sfp->sf_mtx); 1711 if (sfp->sf_si != NULL) { 1712 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1713 } 1714 mtx_unlock(sfp->sf_mtx); 1715 } 1716 free(sfp, M_SELFD); 1717 } 1718 1719 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1720 void 1721 seldrain(struct selinfo *sip) 1722 { 1723 1724 /* 1725 * This feature is already provided by doselwakeup(), thus it is 1726 * enough to go for it. 1727 * Eventually, the context, should take care to avoid races 1728 * between thread calling select()/poll() and file descriptor 1729 * detaching, but, again, the races are just the same as 1730 * selwakeup(). 1731 */ 1732 doselwakeup(sip, -1); 1733 } 1734 1735 /* 1736 * Record a select request. 1737 */ 1738 void 1739 selrecord(struct thread *selector, struct selinfo *sip) 1740 { 1741 struct selfd *sfp; 1742 struct seltd *stp; 1743 struct mtx *mtxp; 1744 1745 stp = selector->td_sel; 1746 /* 1747 * Don't record when doing a rescan. 1748 */ 1749 if (stp->st_flags & SELTD_RESCAN) 1750 return; 1751 /* 1752 * Grab one of the preallocated descriptors. 1753 */ 1754 sfp = NULL; 1755 if ((sfp = stp->st_free1) != NULL) 1756 stp->st_free1 = NULL; 1757 else if ((sfp = stp->st_free2) != NULL) 1758 stp->st_free2 = NULL; 1759 else 1760 panic("selrecord: No free selfd on selq"); 1761 mtxp = sip->si_mtx; 1762 if (mtxp == NULL) 1763 mtxp = mtx_pool_find(mtxpool_select, sip); 1764 /* 1765 * Initialize the sfp and queue it in the thread. 1766 */ 1767 sfp->sf_si = sip; 1768 sfp->sf_mtx = mtxp; 1769 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1770 /* 1771 * Now that we've locked the sip, check for initialization. 1772 */ 1773 mtx_lock(mtxp); 1774 if (sip->si_mtx == NULL) { 1775 sip->si_mtx = mtxp; 1776 TAILQ_INIT(&sip->si_tdlist); 1777 } 1778 /* 1779 * Add this thread to the list of selfds listening on this selinfo. 1780 */ 1781 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1782 mtx_unlock(sip->si_mtx); 1783 } 1784 1785 /* Wake up a selecting thread. */ 1786 void 1787 selwakeup(struct selinfo *sip) 1788 { 1789 doselwakeup(sip, -1); 1790 } 1791 1792 /* Wake up a selecting thread, and set its priority. */ 1793 void 1794 selwakeuppri(struct selinfo *sip, int pri) 1795 { 1796 doselwakeup(sip, pri); 1797 } 1798 1799 /* 1800 * Do a wakeup when a selectable event occurs. 1801 */ 1802 static void 1803 doselwakeup(struct selinfo *sip, int pri) 1804 { 1805 struct selfd *sfp; 1806 struct selfd *sfn; 1807 struct seltd *stp; 1808 1809 /* If it's not initialized there can't be any waiters. */ 1810 if (sip->si_mtx == NULL) 1811 return; 1812 /* 1813 * Locking the selinfo locks all selfds associated with it. 1814 */ 1815 mtx_lock(sip->si_mtx); 1816 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1817 /* 1818 * Once we remove this sfp from the list and clear the 1819 * sf_si seltdclear will know to ignore this si. 1820 */ 1821 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1822 stp = sfp->sf_td; 1823 /* 1824 * Paired with selfdfree. 1825 */ 1826 atomic_store_rel_ptr((uintptr_t *)&sfp->sf_si, (uintptr_t)NULL); 1827 mtx_lock(&stp->st_mtx); 1828 stp->st_flags |= SELTD_PENDING; 1829 cv_broadcastpri(&stp->st_wait, pri); 1830 mtx_unlock(&stp->st_mtx); 1831 } 1832 mtx_unlock(sip->si_mtx); 1833 } 1834 1835 static void 1836 seltdinit(struct thread *td) 1837 { 1838 struct seltd *stp; 1839 1840 if ((stp = td->td_sel) != NULL) 1841 goto out; 1842 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1843 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1844 cv_init(&stp->st_wait, "select"); 1845 out: 1846 stp->st_flags = 0; 1847 STAILQ_INIT(&stp->st_selq); 1848 } 1849 1850 static int 1851 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1852 { 1853 struct seltd *stp; 1854 int error; 1855 1856 stp = td->td_sel; 1857 /* 1858 * An event of interest may occur while we do not hold the seltd 1859 * locked so check the pending flag before we sleep. 1860 */ 1861 mtx_lock(&stp->st_mtx); 1862 /* 1863 * Any further calls to selrecord will be a rescan. 1864 */ 1865 stp->st_flags |= SELTD_RESCAN; 1866 if (stp->st_flags & SELTD_PENDING) { 1867 mtx_unlock(&stp->st_mtx); 1868 return (0); 1869 } 1870 if (sbt == 0) 1871 error = EWOULDBLOCK; 1872 else if (sbt != -1) 1873 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 1874 sbt, precision, C_ABSOLUTE); 1875 else 1876 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1877 mtx_unlock(&stp->st_mtx); 1878 1879 return (error); 1880 } 1881 1882 void 1883 seltdfini(struct thread *td) 1884 { 1885 struct seltd *stp; 1886 1887 stp = td->td_sel; 1888 if (stp == NULL) 1889 return; 1890 if (stp->st_free1) 1891 free(stp->st_free1, M_SELFD); 1892 if (stp->st_free2) 1893 free(stp->st_free2, M_SELFD); 1894 td->td_sel = NULL; 1895 cv_destroy(&stp->st_wait); 1896 mtx_destroy(&stp->st_mtx); 1897 free(stp, M_SELECT); 1898 } 1899 1900 /* 1901 * Remove the references to the thread from all of the objects we were 1902 * polling. 1903 */ 1904 static void 1905 seltdclear(struct thread *td) 1906 { 1907 struct seltd *stp; 1908 struct selfd *sfp; 1909 struct selfd *sfn; 1910 1911 stp = td->td_sel; 1912 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1913 selfdfree(stp, sfp); 1914 stp->st_flags = 0; 1915 } 1916 1917 static void selectinit(void *); 1918 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1919 static void 1920 selectinit(void *dummy __unused) 1921 { 1922 1923 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 1924 } 1925 1926 /* 1927 * Set up a syscall return value that follows the convention specified for 1928 * posix_* functions. 1929 */ 1930 int 1931 kern_posix_error(struct thread *td, int error) 1932 { 1933 1934 if (error <= 0) 1935 return (error); 1936 td->td_errno = error; 1937 td->td_pflags |= TDP_NERRNO; 1938 td->td_retval[0] = error; 1939 return (0); 1940 } 1941