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/eventfd.h> 59 #include <sys/kernel.h> 60 #include <sys/ktr.h> 61 #include <sys/limits.h> 62 #include <sys/malloc.h> 63 #include <sys/poll.h> 64 #include <sys/resourcevar.h> 65 #include <sys/selinfo.h> 66 #include <sys/sleepqueue.h> 67 #include <sys/specialfd.h> 68 #include <sys/syscallsubr.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysent.h> 71 #include <sys/vnode.h> 72 #include <sys/bio.h> 73 #include <sys/buf.h> 74 #include <sys/condvar.h> 75 #ifdef KTRACE 76 #include <sys/ktrace.h> 77 #endif 78 79 #include <security/audit/audit.h> 80 81 /* 82 * The following macro defines how many bytes will be allocated from 83 * the stack instead of memory allocated when passing the IOCTL data 84 * structures from userspace and to the kernel. Some IOCTLs having 85 * small data structures are used very frequently and this small 86 * buffer on the stack gives a significant speedup improvement for 87 * those requests. The value of this define should be greater or equal 88 * to 64 bytes and should also be power of two. The data structure is 89 * currently hard-aligned to a 8-byte boundary on the stack. This 90 * should currently be sufficient for all supported platforms. 91 */ 92 #define SYS_IOCTL_SMALL_SIZE 128 /* bytes */ 93 #define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */ 94 95 #ifdef __LP64__ 96 static int iosize_max_clamp = 0; 97 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, 98 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); 99 static int devfs_iosize_max_clamp = 1; 100 SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW, 101 &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices"); 102 #endif 103 104 /* 105 * Assert that the return value of read(2) and write(2) syscalls fits 106 * into a register. If not, an architecture will need to provide the 107 * usermode wrappers to reconstruct the result. 108 */ 109 CTASSERT(sizeof(register_t) >= sizeof(size_t)); 110 111 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 112 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); 113 MALLOC_DEFINE(M_IOV, "iov", "large iov's"); 114 115 static int pollout(struct thread *, struct pollfd *, struct pollfd *, 116 u_int); 117 static int pollscan(struct thread *, struct pollfd *, u_int); 118 static int pollrescan(struct thread *); 119 static int selscan(struct thread *, fd_mask **, fd_mask **, int); 120 static int selrescan(struct thread *, fd_mask **, fd_mask **); 121 static void selfdalloc(struct thread *, void *); 122 static void selfdfree(struct seltd *, struct selfd *); 123 static int dofileread(struct thread *, int, struct file *, struct uio *, 124 off_t, int); 125 static int dofilewrite(struct thread *, int, struct file *, struct uio *, 126 off_t, int); 127 static void doselwakeup(struct selinfo *, int); 128 static void seltdinit(struct thread *); 129 static int seltdwait(struct thread *, sbintime_t, sbintime_t); 130 static void seltdclear(struct thread *); 131 132 /* 133 * One seltd per-thread allocated on demand as needed. 134 * 135 * t - protected by st_mtx 136 * k - Only accessed by curthread or read-only 137 */ 138 struct seltd { 139 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ 140 struct selfd *st_free1; /* (k) free fd for read set. */ 141 struct selfd *st_free2; /* (k) free fd for write set. */ 142 struct mtx st_mtx; /* Protects struct seltd */ 143 struct cv st_wait; /* (t) Wait channel. */ 144 int st_flags; /* (t) SELTD_ flags. */ 145 }; 146 147 #define SELTD_PENDING 0x0001 /* We have pending events. */ 148 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */ 149 150 /* 151 * One selfd allocated per-thread per-file-descriptor. 152 * f - protected by sf_mtx 153 */ 154 struct selfd { 155 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ 156 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ 157 struct selinfo *sf_si; /* (f) selinfo when linked. */ 158 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ 159 struct seltd *sf_td; /* (k) owning seltd. */ 160 void *sf_cookie; /* (k) fd or pollfd. */ 161 }; 162 163 MALLOC_DEFINE(M_SELFD, "selfd", "selfd"); 164 static struct mtx_pool *mtxpool_select; 165 166 #ifdef __LP64__ 167 size_t 168 devfs_iosize_max(void) 169 { 170 171 return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 172 INT_MAX : SSIZE_MAX); 173 } 174 175 size_t 176 iosize_max(void) 177 { 178 179 return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 180 INT_MAX : SSIZE_MAX); 181 } 182 #endif 183 184 #ifndef _SYS_SYSPROTO_H_ 185 struct read_args { 186 int fd; 187 void *buf; 188 size_t nbyte; 189 }; 190 #endif 191 int 192 sys_read(struct thread *td, struct read_args *uap) 193 { 194 struct uio auio; 195 struct iovec aiov; 196 int error; 197 198 if (uap->nbyte > IOSIZE_MAX) 199 return (EINVAL); 200 aiov.iov_base = uap->buf; 201 aiov.iov_len = uap->nbyte; 202 auio.uio_iov = &aiov; 203 auio.uio_iovcnt = 1; 204 auio.uio_resid = uap->nbyte; 205 auio.uio_segflg = UIO_USERSPACE; 206 error = kern_readv(td, uap->fd, &auio); 207 return (error); 208 } 209 210 /* 211 * Positioned read system call 212 */ 213 #ifndef _SYS_SYSPROTO_H_ 214 struct pread_args { 215 int fd; 216 void *buf; 217 size_t nbyte; 218 int pad; 219 off_t offset; 220 }; 221 #endif 222 int 223 sys_pread(struct thread *td, struct pread_args *uap) 224 { 225 226 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 227 } 228 229 int 230 kern_pread(struct thread *td, int fd, void *buf, size_t nbyte, off_t offset) 231 { 232 struct uio auio; 233 struct iovec aiov; 234 int error; 235 236 if (nbyte > IOSIZE_MAX) 237 return (EINVAL); 238 aiov.iov_base = buf; 239 aiov.iov_len = nbyte; 240 auio.uio_iov = &aiov; 241 auio.uio_iovcnt = 1; 242 auio.uio_resid = nbyte; 243 auio.uio_segflg = UIO_USERSPACE; 244 error = kern_preadv(td, fd, &auio, offset); 245 return (error); 246 } 247 248 #if defined(COMPAT_FREEBSD6) 249 int 250 freebsd6_pread(struct thread *td, struct freebsd6_pread_args *uap) 251 { 252 253 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 254 } 255 #endif 256 257 /* 258 * Scatter read system call. 259 */ 260 #ifndef _SYS_SYSPROTO_H_ 261 struct readv_args { 262 int fd; 263 struct iovec *iovp; 264 u_int iovcnt; 265 }; 266 #endif 267 int 268 sys_readv(struct thread *td, struct readv_args *uap) 269 { 270 struct uio *auio; 271 int error; 272 273 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 274 if (error) 275 return (error); 276 error = kern_readv(td, uap->fd, auio); 277 free(auio, M_IOV); 278 return (error); 279 } 280 281 int 282 kern_readv(struct thread *td, int fd, struct uio *auio) 283 { 284 struct file *fp; 285 int error; 286 287 error = fget_read(td, fd, &cap_read_rights, &fp); 288 if (error) 289 return (error); 290 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 291 fdrop(fp, td); 292 return (error); 293 } 294 295 /* 296 * Scatter positioned read system call. 297 */ 298 #ifndef _SYS_SYSPROTO_H_ 299 struct preadv_args { 300 int fd; 301 struct iovec *iovp; 302 u_int iovcnt; 303 off_t offset; 304 }; 305 #endif 306 int 307 sys_preadv(struct thread *td, struct preadv_args *uap) 308 { 309 struct uio *auio; 310 int error; 311 312 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 313 if (error) 314 return (error); 315 error = kern_preadv(td, uap->fd, auio, uap->offset); 316 free(auio, M_IOV); 317 return (error); 318 } 319 320 int 321 kern_preadv(struct thread *td, int fd, struct uio *auio, off_t offset) 322 { 323 struct file *fp; 324 int error; 325 326 error = fget_read(td, fd, &cap_pread_rights, &fp); 327 if (error) 328 return (error); 329 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 330 error = ESPIPE; 331 else if (offset < 0 && 332 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 333 error = EINVAL; 334 else 335 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 336 fdrop(fp, td); 337 return (error); 338 } 339 340 /* 341 * Common code for readv and preadv that reads data in 342 * from a file using the passed in uio, offset, and flags. 343 */ 344 static int 345 dofileread(struct thread *td, int fd, struct file *fp, struct uio *auio, 346 off_t offset, int flags) 347 { 348 ssize_t cnt; 349 int error; 350 #ifdef KTRACE 351 struct uio *ktruio = NULL; 352 #endif 353 354 AUDIT_ARG_FD(fd); 355 356 /* Finish zero length reads right here */ 357 if (auio->uio_resid == 0) { 358 td->td_retval[0] = 0; 359 return (0); 360 } 361 auio->uio_rw = UIO_READ; 362 auio->uio_offset = offset; 363 auio->uio_td = td; 364 #ifdef KTRACE 365 if (KTRPOINT(td, KTR_GENIO)) 366 ktruio = cloneuio(auio); 367 #endif 368 cnt = auio->uio_resid; 369 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 370 if (auio->uio_resid != cnt && (error == ERESTART || 371 error == EINTR || error == EWOULDBLOCK)) 372 error = 0; 373 } 374 cnt -= auio->uio_resid; 375 #ifdef KTRACE 376 if (ktruio != NULL) { 377 ktruio->uio_resid = cnt; 378 ktrgenio(fd, UIO_READ, ktruio, error); 379 } 380 #endif 381 td->td_retval[0] = cnt; 382 return (error); 383 } 384 385 #ifndef _SYS_SYSPROTO_H_ 386 struct write_args { 387 int fd; 388 const void *buf; 389 size_t nbyte; 390 }; 391 #endif 392 int 393 sys_write(struct thread *td, struct write_args *uap) 394 { 395 struct uio auio; 396 struct iovec aiov; 397 int error; 398 399 if (uap->nbyte > IOSIZE_MAX) 400 return (EINVAL); 401 aiov.iov_base = (void *)(uintptr_t)uap->buf; 402 aiov.iov_len = uap->nbyte; 403 auio.uio_iov = &aiov; 404 auio.uio_iovcnt = 1; 405 auio.uio_resid = uap->nbyte; 406 auio.uio_segflg = UIO_USERSPACE; 407 error = kern_writev(td, uap->fd, &auio); 408 return (error); 409 } 410 411 /* 412 * Positioned write system call. 413 */ 414 #ifndef _SYS_SYSPROTO_H_ 415 struct pwrite_args { 416 int fd; 417 const void *buf; 418 size_t nbyte; 419 int pad; 420 off_t offset; 421 }; 422 #endif 423 int 424 sys_pwrite(struct thread *td, struct pwrite_args *uap) 425 { 426 427 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 428 } 429 430 int 431 kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte, 432 off_t offset) 433 { 434 struct uio auio; 435 struct iovec aiov; 436 int error; 437 438 if (nbyte > IOSIZE_MAX) 439 return (EINVAL); 440 aiov.iov_base = (void *)(uintptr_t)buf; 441 aiov.iov_len = nbyte; 442 auio.uio_iov = &aiov; 443 auio.uio_iovcnt = 1; 444 auio.uio_resid = nbyte; 445 auio.uio_segflg = UIO_USERSPACE; 446 error = kern_pwritev(td, fd, &auio, offset); 447 return (error); 448 } 449 450 #if defined(COMPAT_FREEBSD6) 451 int 452 freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap) 453 { 454 455 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 456 } 457 #endif 458 459 /* 460 * Gather write system call. 461 */ 462 #ifndef _SYS_SYSPROTO_H_ 463 struct writev_args { 464 int fd; 465 struct iovec *iovp; 466 u_int iovcnt; 467 }; 468 #endif 469 int 470 sys_writev(struct thread *td, struct writev_args *uap) 471 { 472 struct uio *auio; 473 int error; 474 475 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 476 if (error) 477 return (error); 478 error = kern_writev(td, uap->fd, auio); 479 free(auio, M_IOV); 480 return (error); 481 } 482 483 int 484 kern_writev(struct thread *td, int fd, struct uio *auio) 485 { 486 struct file *fp; 487 int error; 488 489 error = fget_write(td, fd, &cap_write_rights, &fp); 490 if (error) 491 return (error); 492 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 493 fdrop(fp, td); 494 return (error); 495 } 496 497 /* 498 * Gather positioned write system call. 499 */ 500 #ifndef _SYS_SYSPROTO_H_ 501 struct pwritev_args { 502 int fd; 503 struct iovec *iovp; 504 u_int iovcnt; 505 off_t offset; 506 }; 507 #endif 508 int 509 sys_pwritev(struct thread *td, struct pwritev_args *uap) 510 { 511 struct uio *auio; 512 int error; 513 514 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 515 if (error) 516 return (error); 517 error = kern_pwritev(td, uap->fd, auio, uap->offset); 518 free(auio, M_IOV); 519 return (error); 520 } 521 522 int 523 kern_pwritev(struct thread *td, int fd, struct uio *auio, off_t offset) 524 { 525 struct file *fp; 526 int error; 527 528 error = fget_write(td, fd, &cap_pwrite_rights, &fp); 529 if (error) 530 return (error); 531 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 532 error = ESPIPE; 533 else if (offset < 0 && 534 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 535 error = EINVAL; 536 else 537 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 538 fdrop(fp, td); 539 return (error); 540 } 541 542 /* 543 * Common code for writev and pwritev that writes data to 544 * a file using the passed in uio, offset, and flags. 545 */ 546 static int 547 dofilewrite(struct thread *td, int fd, struct file *fp, struct uio *auio, 548 off_t offset, int flags) 549 { 550 ssize_t cnt; 551 int error; 552 #ifdef KTRACE 553 struct uio *ktruio = NULL; 554 #endif 555 556 AUDIT_ARG_FD(fd); 557 auio->uio_rw = UIO_WRITE; 558 auio->uio_td = td; 559 auio->uio_offset = offset; 560 #ifdef KTRACE 561 if (KTRPOINT(td, KTR_GENIO)) 562 ktruio = cloneuio(auio); 563 #endif 564 cnt = auio->uio_resid; 565 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 566 if (auio->uio_resid != cnt && (error == ERESTART || 567 error == EINTR || error == EWOULDBLOCK)) 568 error = 0; 569 /* Socket layer is responsible for issuing SIGPIPE. */ 570 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 571 PROC_LOCK(td->td_proc); 572 tdsignal(td, SIGPIPE); 573 PROC_UNLOCK(td->td_proc); 574 } 575 } 576 cnt -= auio->uio_resid; 577 #ifdef KTRACE 578 if (ktruio != NULL) { 579 ktruio->uio_resid = cnt; 580 ktrgenio(fd, UIO_WRITE, ktruio, error); 581 } 582 #endif 583 td->td_retval[0] = cnt; 584 return (error); 585 } 586 587 /* 588 * Truncate a file given a file descriptor. 589 * 590 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 591 * descriptor isn't writable. 592 */ 593 int 594 kern_ftruncate(struct thread *td, int fd, off_t length) 595 { 596 struct file *fp; 597 int error; 598 599 AUDIT_ARG_FD(fd); 600 if (length < 0) 601 return (EINVAL); 602 error = fget(td, fd, &cap_ftruncate_rights, &fp); 603 if (error) 604 return (error); 605 AUDIT_ARG_FILE(td->td_proc, fp); 606 if (!(fp->f_flag & FWRITE)) { 607 fdrop(fp, td); 608 return (EINVAL); 609 } 610 error = fo_truncate(fp, length, td->td_ucred, td); 611 fdrop(fp, td); 612 return (error); 613 } 614 615 #ifndef _SYS_SYSPROTO_H_ 616 struct ftruncate_args { 617 int fd; 618 int pad; 619 off_t length; 620 }; 621 #endif 622 int 623 sys_ftruncate(struct thread *td, struct ftruncate_args *uap) 624 { 625 626 return (kern_ftruncate(td, uap->fd, uap->length)); 627 } 628 629 #if defined(COMPAT_43) 630 #ifndef _SYS_SYSPROTO_H_ 631 struct oftruncate_args { 632 int fd; 633 long length; 634 }; 635 #endif 636 int 637 oftruncate(struct thread *td, struct oftruncate_args *uap) 638 { 639 640 return (kern_ftruncate(td, uap->fd, uap->length)); 641 } 642 #endif /* COMPAT_43 */ 643 644 #ifndef _SYS_SYSPROTO_H_ 645 struct ioctl_args { 646 int fd; 647 u_long com; 648 caddr_t data; 649 }; 650 #endif 651 /* ARGSUSED */ 652 int 653 sys_ioctl(struct thread *td, struct ioctl_args *uap) 654 { 655 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); 656 uint32_t com; 657 int arg, error; 658 u_int size; 659 caddr_t data; 660 661 #ifdef INVARIANTS 662 if (uap->com > 0xffffffff) { 663 printf( 664 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 665 td->td_proc->p_pid, td->td_name, uap->com); 666 } 667 #endif 668 com = (uint32_t)uap->com; 669 670 /* 671 * Interpret high order word to find amount of data to be 672 * copied to/from the user's address space. 673 */ 674 size = IOCPARM_LEN(com); 675 if ((size > IOCPARM_MAX) || 676 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 677 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 678 ((com & IOC_OUT) && size == 0) || 679 #else 680 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 681 #endif 682 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 683 return (ENOTTY); 684 685 if (size > 0) { 686 if (com & IOC_VOID) { 687 /* Integer argument. */ 688 arg = (intptr_t)uap->data; 689 data = (void *)&arg; 690 size = 0; 691 } else { 692 if (size > SYS_IOCTL_SMALL_SIZE) 693 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 694 else 695 data = smalldata; 696 } 697 } else 698 data = (void *)&uap->data; 699 if (com & IOC_IN) { 700 error = copyin(uap->data, data, (u_int)size); 701 if (error != 0) 702 goto out; 703 } else if (com & IOC_OUT) { 704 /* 705 * Zero the buffer so the user always 706 * gets back something deterministic. 707 */ 708 bzero(data, size); 709 } 710 711 error = kern_ioctl(td, uap->fd, com, data); 712 713 if (error == 0 && (com & IOC_OUT)) 714 error = copyout(data, uap->data, (u_int)size); 715 716 out: 717 if (size > SYS_IOCTL_SMALL_SIZE) 718 free(data, M_IOCTLOPS); 719 return (error); 720 } 721 722 int 723 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 724 { 725 struct file *fp; 726 struct filedesc *fdp; 727 int error, tmp, locked; 728 729 AUDIT_ARG_FD(fd); 730 AUDIT_ARG_CMD(com); 731 732 fdp = td->td_proc->p_fd; 733 734 switch (com) { 735 case FIONCLEX: 736 case FIOCLEX: 737 FILEDESC_XLOCK(fdp); 738 locked = LA_XLOCKED; 739 break; 740 default: 741 #ifdef CAPABILITIES 742 FILEDESC_SLOCK(fdp); 743 locked = LA_SLOCKED; 744 #else 745 locked = LA_UNLOCKED; 746 #endif 747 break; 748 } 749 750 #ifdef CAPABILITIES 751 if ((fp = fget_noref(fdp, fd)) == NULL) { 752 error = EBADF; 753 goto out; 754 } 755 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 756 fp = NULL; /* fhold() was not called yet */ 757 goto out; 758 } 759 if (!fhold(fp)) { 760 error = EBADF; 761 fp = NULL; 762 goto out; 763 } 764 if (locked == LA_SLOCKED) { 765 FILEDESC_SUNLOCK(fdp); 766 locked = LA_UNLOCKED; 767 } 768 #else 769 error = fget(td, fd, &cap_ioctl_rights, &fp); 770 if (error != 0) { 771 fp = NULL; 772 goto out; 773 } 774 #endif 775 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 776 error = EBADF; 777 goto out; 778 } 779 780 switch (com) { 781 case FIONCLEX: 782 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 783 goto out; 784 case FIOCLEX: 785 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 786 goto out; 787 case FIONBIO: 788 if ((tmp = *(int *)data)) 789 atomic_set_int(&fp->f_flag, FNONBLOCK); 790 else 791 atomic_clear_int(&fp->f_flag, FNONBLOCK); 792 data = (void *)&tmp; 793 break; 794 case FIOASYNC: 795 if ((tmp = *(int *)data)) 796 atomic_set_int(&fp->f_flag, FASYNC); 797 else 798 atomic_clear_int(&fp->f_flag, FASYNC); 799 data = (void *)&tmp; 800 break; 801 } 802 803 error = fo_ioctl(fp, com, data, td->td_ucred, td); 804 out: 805 switch (locked) { 806 case LA_XLOCKED: 807 FILEDESC_XUNLOCK(fdp); 808 break; 809 #ifdef CAPABILITIES 810 case LA_SLOCKED: 811 FILEDESC_SUNLOCK(fdp); 812 break; 813 #endif 814 default: 815 FILEDESC_UNLOCK_ASSERT(fdp); 816 break; 817 } 818 if (fp != NULL) 819 fdrop(fp, td); 820 return (error); 821 } 822 823 int 824 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap) 825 { 826 int error; 827 828 error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len); 829 return (kern_posix_error(td, error)); 830 } 831 832 int 833 kern_posix_fallocate(struct thread *td, int fd, off_t offset, off_t len) 834 { 835 struct file *fp; 836 int error; 837 838 AUDIT_ARG_FD(fd); 839 if (offset < 0 || len <= 0) 840 return (EINVAL); 841 /* Check for wrap. */ 842 if (offset > OFF_MAX - len) 843 return (EFBIG); 844 AUDIT_ARG_FD(fd); 845 error = fget(td, fd, &cap_pwrite_rights, &fp); 846 if (error != 0) 847 return (error); 848 AUDIT_ARG_FILE(td->td_proc, fp); 849 if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) { 850 error = ESPIPE; 851 goto out; 852 } 853 if ((fp->f_flag & FWRITE) == 0) { 854 error = EBADF; 855 goto out; 856 } 857 858 error = fo_fallocate(fp, offset, len, td); 859 out: 860 fdrop(fp, td); 861 return (error); 862 } 863 864 int 865 sys_fspacectl(struct thread *td, struct fspacectl_args *uap) 866 { 867 struct spacectl_range rqsr, rmsr; 868 int error, cerror; 869 870 error = copyin(uap->rqsr, &rqsr, sizeof(rqsr)); 871 if (error != 0) 872 return (error); 873 874 error = kern_fspacectl(td, uap->fd, uap->cmd, &rqsr, uap->flags, 875 &rmsr); 876 if (uap->rmsr != NULL) { 877 cerror = copyout(&rmsr, uap->rmsr, sizeof(rmsr)); 878 if (error == 0) 879 error = cerror; 880 } 881 return (error); 882 } 883 884 int 885 kern_fspacectl(struct thread *td, int fd, int cmd, 886 const struct spacectl_range *rqsr, int flags, struct spacectl_range *rmsrp) 887 { 888 struct file *fp; 889 struct spacectl_range rmsr; 890 int error; 891 892 AUDIT_ARG_FD(fd); 893 AUDIT_ARG_CMD(cmd); 894 AUDIT_ARG_FFLAGS(flags); 895 896 if (rqsr == NULL) 897 return (EINVAL); 898 rmsr = *rqsr; 899 if (rmsrp != NULL) 900 *rmsrp = rmsr; 901 902 if (cmd != SPACECTL_DEALLOC || 903 rqsr->r_offset < 0 || rqsr->r_len <= 0 || 904 rqsr->r_offset > OFF_MAX - rqsr->r_len || 905 (flags & ~SPACECTL_F_SUPPORTED) != 0) 906 return (EINVAL); 907 908 error = fget_write(td, fd, &cap_pwrite_rights, &fp); 909 if (error != 0) 910 return (error); 911 AUDIT_ARG_FILE(td->td_proc, fp); 912 if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) { 913 error = ESPIPE; 914 goto out; 915 } 916 if ((fp->f_flag & FWRITE) == 0) { 917 error = EBADF; 918 goto out; 919 } 920 921 error = fo_fspacectl(fp, cmd, &rmsr.r_offset, &rmsr.r_len, flags, 922 td->td_ucred, td); 923 /* fspacectl is not restarted after signals if the file is modified. */ 924 if (rmsr.r_len != rqsr->r_len && (error == ERESTART || 925 error == EINTR || error == EWOULDBLOCK)) 926 error = 0; 927 if (rmsrp != NULL) 928 *rmsrp = rmsr; 929 out: 930 fdrop(fp, td); 931 return (error); 932 } 933 934 int 935 kern_specialfd(struct thread *td, int type, void *arg) 936 { 937 struct file *fp; 938 struct specialfd_eventfd *ae; 939 int error, fd, fflags; 940 941 fflags = 0; 942 error = falloc_noinstall(td, &fp); 943 if (error != 0) 944 return (error); 945 946 switch (type) { 947 case SPECIALFD_EVENTFD: 948 ae = arg; 949 if ((ae->flags & EFD_CLOEXEC) != 0) 950 fflags |= O_CLOEXEC; 951 error = eventfd_create_file(td, fp, ae->initval, ae->flags); 952 break; 953 default: 954 error = EINVAL; 955 break; 956 } 957 958 if (error == 0) 959 error = finstall(td, fp, &fd, fflags, NULL); 960 fdrop(fp, td); 961 if (error == 0) 962 td->td_retval[0] = fd; 963 return (error); 964 } 965 966 int 967 sys___specialfd(struct thread *td, struct __specialfd_args *args) 968 { 969 struct specialfd_eventfd ae; 970 int error; 971 972 switch (args->type) { 973 case SPECIALFD_EVENTFD: 974 if (args->len != sizeof(struct specialfd_eventfd)) { 975 error = EINVAL; 976 break; 977 } 978 error = copyin(args->req, &ae, sizeof(ae)); 979 if (error != 0) 980 break; 981 if ((ae.flags & ~(EFD_CLOEXEC | EFD_NONBLOCK | 982 EFD_SEMAPHORE)) != 0) { 983 error = EINVAL; 984 break; 985 } 986 error = kern_specialfd(td, args->type, &ae); 987 break; 988 default: 989 error = EINVAL; 990 break; 991 } 992 return (error); 993 } 994 995 int 996 poll_no_poll(int events) 997 { 998 /* 999 * Return true for read/write. If the user asked for something 1000 * special, return POLLNVAL, so that clients have a way of 1001 * determining reliably whether or not the extended 1002 * functionality is present without hard-coding knowledge 1003 * of specific filesystem implementations. 1004 */ 1005 if (events & ~POLLSTANDARD) 1006 return (POLLNVAL); 1007 1008 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 1009 } 1010 1011 int 1012 sys_pselect(struct thread *td, struct pselect_args *uap) 1013 { 1014 struct timespec ts; 1015 struct timeval tv, *tvp; 1016 sigset_t set, *uset; 1017 int error; 1018 1019 if (uap->ts != NULL) { 1020 error = copyin(uap->ts, &ts, sizeof(ts)); 1021 if (error != 0) 1022 return (error); 1023 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1024 tvp = &tv; 1025 } else 1026 tvp = NULL; 1027 if (uap->sm != NULL) { 1028 error = copyin(uap->sm, &set, sizeof(set)); 1029 if (error != 0) 1030 return (error); 1031 uset = &set; 1032 } else 1033 uset = NULL; 1034 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 1035 uset, NFDBITS)); 1036 } 1037 1038 int 1039 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 1040 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 1041 { 1042 int error; 1043 1044 if (uset != NULL) { 1045 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1046 &td->td_oldsigmask, 0); 1047 if (error != 0) 1048 return (error); 1049 td->td_pflags |= TDP_OLDMASK; 1050 /* 1051 * Make sure that ast() is called on return to 1052 * usermode and TDP_OLDMASK is cleared, restoring old 1053 * sigmask. 1054 */ 1055 ast_sched(td, TDA_SIGSUSPEND); 1056 } 1057 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 1058 return (error); 1059 } 1060 1061 #ifndef _SYS_SYSPROTO_H_ 1062 struct select_args { 1063 int nd; 1064 fd_set *in, *ou, *ex; 1065 struct timeval *tv; 1066 }; 1067 #endif 1068 int 1069 sys_select(struct thread *td, struct select_args *uap) 1070 { 1071 struct timeval tv, *tvp; 1072 int error; 1073 1074 if (uap->tv != NULL) { 1075 error = copyin(uap->tv, &tv, sizeof(tv)); 1076 if (error) 1077 return (error); 1078 tvp = &tv; 1079 } else 1080 tvp = NULL; 1081 1082 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 1083 NFDBITS)); 1084 } 1085 1086 /* 1087 * In the unlikely case when user specified n greater then the last 1088 * open file descriptor, check that no bits are set after the last 1089 * valid fd. We must return EBADF if any is set. 1090 * 1091 * There are applications that rely on the behaviour. 1092 * 1093 * nd is fd_nfiles. 1094 */ 1095 static int 1096 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 1097 { 1098 char *addr, *oaddr; 1099 int b, i, res; 1100 uint8_t bits; 1101 1102 if (nd >= ndu || fd_in == NULL) 1103 return (0); 1104 1105 oaddr = NULL; 1106 bits = 0; /* silence gcc */ 1107 for (i = nd; i < ndu; i++) { 1108 b = i / NBBY; 1109 #if BYTE_ORDER == LITTLE_ENDIAN 1110 addr = (char *)fd_in + b; 1111 #else 1112 addr = (char *)fd_in; 1113 if (abi_nfdbits == NFDBITS) { 1114 addr += rounddown(b, sizeof(fd_mask)) + 1115 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 1116 } else { 1117 addr += rounddown(b, sizeof(uint32_t)) + 1118 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 1119 } 1120 #endif 1121 if (addr != oaddr) { 1122 res = fubyte(addr); 1123 if (res == -1) 1124 return (EFAULT); 1125 oaddr = addr; 1126 bits = res; 1127 } 1128 if ((bits & (1 << (i % NBBY))) != 0) 1129 return (EBADF); 1130 } 1131 return (0); 1132 } 1133 1134 int 1135 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 1136 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 1137 { 1138 struct filedesc *fdp; 1139 /* 1140 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 1141 * infds with the new FD_SETSIZE of 1024, and more than enough for 1142 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 1143 * of 256. 1144 */ 1145 fd_mask s_selbits[howmany(2048, NFDBITS)]; 1146 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 1147 struct timeval rtv; 1148 sbintime_t asbt, precision, rsbt; 1149 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 1150 int error, lf, ndu; 1151 1152 if (nd < 0) 1153 return (EINVAL); 1154 fdp = td->td_proc->p_fd; 1155 ndu = nd; 1156 lf = fdp->fd_nfiles; 1157 if (nd > lf) 1158 nd = lf; 1159 1160 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 1161 if (error != 0) 1162 return (error); 1163 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 1164 if (error != 0) 1165 return (error); 1166 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 1167 if (error != 0) 1168 return (error); 1169 1170 /* 1171 * Allocate just enough bits for the non-null fd_sets. Use the 1172 * preallocated auto buffer if possible. 1173 */ 1174 nfdbits = roundup(nd, NFDBITS); 1175 ncpbytes = nfdbits / NBBY; 1176 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 1177 nbufbytes = 0; 1178 if (fd_in != NULL) 1179 nbufbytes += 2 * ncpbytes; 1180 if (fd_ou != NULL) 1181 nbufbytes += 2 * ncpbytes; 1182 if (fd_ex != NULL) 1183 nbufbytes += 2 * ncpbytes; 1184 if (nbufbytes <= sizeof s_selbits) 1185 selbits = &s_selbits[0]; 1186 else 1187 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1188 1189 /* 1190 * Assign pointers into the bit buffers and fetch the input bits. 1191 * Put the output buffers together so that they can be bzeroed 1192 * together. 1193 */ 1194 sbp = selbits; 1195 #define getbits(name, x) \ 1196 do { \ 1197 if (name == NULL) { \ 1198 ibits[x] = NULL; \ 1199 obits[x] = NULL; \ 1200 } else { \ 1201 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1202 obits[x] = sbp; \ 1203 sbp += ncpbytes / sizeof *sbp; \ 1204 error = copyin(name, ibits[x], ncpubytes); \ 1205 if (error != 0) \ 1206 goto done; \ 1207 if (ncpbytes != ncpubytes) \ 1208 bzero((char *)ibits[x] + ncpubytes, \ 1209 ncpbytes - ncpubytes); \ 1210 } \ 1211 } while (0) 1212 getbits(fd_in, 0); 1213 getbits(fd_ou, 1); 1214 getbits(fd_ex, 2); 1215 #undef getbits 1216 1217 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1218 /* 1219 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1220 * we are running under 32-bit emulation. This should be more 1221 * generic. 1222 */ 1223 #define swizzle_fdset(bits) \ 1224 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1225 int i; \ 1226 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1227 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1228 } 1229 #else 1230 #define swizzle_fdset(bits) 1231 #endif 1232 1233 /* Make sure the bit order makes it through an ABI transition */ 1234 swizzle_fdset(ibits[0]); 1235 swizzle_fdset(ibits[1]); 1236 swizzle_fdset(ibits[2]); 1237 1238 if (nbufbytes != 0) 1239 bzero(selbits, nbufbytes / 2); 1240 1241 precision = 0; 1242 if (tvp != NULL) { 1243 rtv = *tvp; 1244 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1245 rtv.tv_usec >= 1000000) { 1246 error = EINVAL; 1247 goto done; 1248 } 1249 if (!timevalisset(&rtv)) 1250 asbt = 0; 1251 else if (rtv.tv_sec <= INT32_MAX) { 1252 rsbt = tvtosbt(rtv); 1253 precision = rsbt; 1254 precision >>= tc_precexp; 1255 if (TIMESEL(&asbt, rsbt)) 1256 asbt += tc_tick_sbt; 1257 if (asbt <= SBT_MAX - rsbt) 1258 asbt += rsbt; 1259 else 1260 asbt = -1; 1261 } else 1262 asbt = -1; 1263 } else 1264 asbt = -1; 1265 seltdinit(td); 1266 /* Iterate until the timeout expires or descriptors become ready. */ 1267 for (;;) { 1268 error = selscan(td, ibits, obits, nd); 1269 if (error || td->td_retval[0] != 0) 1270 break; 1271 error = seltdwait(td, asbt, precision); 1272 if (error) 1273 break; 1274 error = selrescan(td, ibits, obits); 1275 if (error || td->td_retval[0] != 0) 1276 break; 1277 } 1278 seltdclear(td); 1279 1280 done: 1281 /* select is not restarted after signals... */ 1282 if (error == ERESTART) 1283 error = EINTR; 1284 if (error == EWOULDBLOCK) 1285 error = 0; 1286 1287 /* swizzle bit order back, if necessary */ 1288 swizzle_fdset(obits[0]); 1289 swizzle_fdset(obits[1]); 1290 swizzle_fdset(obits[2]); 1291 #undef swizzle_fdset 1292 1293 #define putbits(name, x) \ 1294 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1295 error = error2; 1296 if (error == 0) { 1297 int error2; 1298 1299 putbits(fd_in, 0); 1300 putbits(fd_ou, 1); 1301 putbits(fd_ex, 2); 1302 #undef putbits 1303 } 1304 if (selbits != &s_selbits[0]) 1305 free(selbits, M_SELECT); 1306 1307 return (error); 1308 } 1309 /* 1310 * Convert a select bit set to poll flags. 1311 * 1312 * The backend always returns POLLHUP/POLLERR if appropriate and we 1313 * return this as a set bit in any set. 1314 */ 1315 static const int select_flags[3] = { 1316 POLLRDNORM | POLLHUP | POLLERR, 1317 POLLWRNORM | POLLHUP | POLLERR, 1318 POLLRDBAND | POLLERR 1319 }; 1320 1321 /* 1322 * Compute the fo_poll flags required for a fd given by the index and 1323 * bit position in the fd_mask array. 1324 */ 1325 static __inline int 1326 selflags(fd_mask **ibits, int idx, fd_mask bit) 1327 { 1328 int flags; 1329 int msk; 1330 1331 flags = 0; 1332 for (msk = 0; msk < 3; msk++) { 1333 if (ibits[msk] == NULL) 1334 continue; 1335 if ((ibits[msk][idx] & bit) == 0) 1336 continue; 1337 flags |= select_flags[msk]; 1338 } 1339 return (flags); 1340 } 1341 1342 /* 1343 * Set the appropriate output bits given a mask of fired events and the 1344 * input bits originally requested. 1345 */ 1346 static __inline int 1347 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1348 { 1349 int msk; 1350 int n; 1351 1352 n = 0; 1353 for (msk = 0; msk < 3; msk++) { 1354 if ((events & select_flags[msk]) == 0) 1355 continue; 1356 if (ibits[msk] == NULL) 1357 continue; 1358 if ((ibits[msk][idx] & bit) == 0) 1359 continue; 1360 /* 1361 * XXX Check for a duplicate set. This can occur because a 1362 * socket calls selrecord() twice for each poll() call 1363 * resulting in two selfds per real fd. selrescan() will 1364 * call selsetbits twice as a result. 1365 */ 1366 if ((obits[msk][idx] & bit) != 0) 1367 continue; 1368 obits[msk][idx] |= bit; 1369 n++; 1370 } 1371 1372 return (n); 1373 } 1374 1375 /* 1376 * Traverse the list of fds attached to this thread's seltd and check for 1377 * completion. 1378 */ 1379 static int 1380 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1381 { 1382 struct filedesc *fdp; 1383 struct selinfo *si; 1384 struct seltd *stp; 1385 struct selfd *sfp; 1386 struct selfd *sfn; 1387 struct file *fp; 1388 fd_mask bit; 1389 int fd, ev, n, idx; 1390 int error; 1391 bool only_user; 1392 1393 fdp = td->td_proc->p_fd; 1394 stp = td->td_sel; 1395 n = 0; 1396 only_user = FILEDESC_IS_ONLY_USER(fdp); 1397 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1398 fd = (int)(uintptr_t)sfp->sf_cookie; 1399 si = sfp->sf_si; 1400 selfdfree(stp, sfp); 1401 /* If the selinfo wasn't cleared the event didn't fire. */ 1402 if (si != NULL) 1403 continue; 1404 if (only_user) 1405 error = fget_only_user(fdp, fd, &cap_event_rights, &fp); 1406 else 1407 error = fget_unlocked(td, fd, &cap_event_rights, &fp); 1408 if (__predict_false(error != 0)) 1409 return (error); 1410 idx = fd / NFDBITS; 1411 bit = (fd_mask)1 << (fd % NFDBITS); 1412 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1413 if (only_user) 1414 fput_only_user(fdp, fp); 1415 else 1416 fdrop(fp, td); 1417 if (ev != 0) 1418 n += selsetbits(ibits, obits, idx, bit, ev); 1419 } 1420 stp->st_flags = 0; 1421 td->td_retval[0] = n; 1422 return (0); 1423 } 1424 1425 /* 1426 * Perform the initial filedescriptor scan and register ourselves with 1427 * each selinfo. 1428 */ 1429 static int 1430 selscan(struct thread *td, fd_mask **ibits, fd_mask **obits, int nfd) 1431 { 1432 struct filedesc *fdp; 1433 struct file *fp; 1434 fd_mask bit; 1435 int ev, flags, end, fd; 1436 int n, idx; 1437 int error; 1438 bool only_user; 1439 1440 fdp = td->td_proc->p_fd; 1441 n = 0; 1442 only_user = FILEDESC_IS_ONLY_USER(fdp); 1443 for (idx = 0, fd = 0; fd < nfd; idx++) { 1444 end = imin(fd + NFDBITS, nfd); 1445 for (bit = 1; fd < end; bit <<= 1, fd++) { 1446 /* Compute the list of events we're interested in. */ 1447 flags = selflags(ibits, idx, bit); 1448 if (flags == 0) 1449 continue; 1450 if (only_user) 1451 error = fget_only_user(fdp, fd, &cap_event_rights, &fp); 1452 else 1453 error = fget_unlocked(td, fd, &cap_event_rights, &fp); 1454 if (__predict_false(error != 0)) 1455 return (error); 1456 selfdalloc(td, (void *)(uintptr_t)fd); 1457 ev = fo_poll(fp, flags, td->td_ucred, td); 1458 if (only_user) 1459 fput_only_user(fdp, fp); 1460 else 1461 fdrop(fp, td); 1462 if (ev != 0) 1463 n += selsetbits(ibits, obits, idx, bit, ev); 1464 } 1465 } 1466 1467 td->td_retval[0] = n; 1468 return (0); 1469 } 1470 1471 int 1472 sys_poll(struct thread *td, struct poll_args *uap) 1473 { 1474 struct timespec ts, *tsp; 1475 1476 if (uap->timeout != INFTIM) { 1477 if (uap->timeout < 0) 1478 return (EINVAL); 1479 ts.tv_sec = uap->timeout / 1000; 1480 ts.tv_nsec = (uap->timeout % 1000) * 1000000; 1481 tsp = &ts; 1482 } else 1483 tsp = NULL; 1484 1485 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); 1486 } 1487 1488 /* 1489 * kfds points to an array in the kernel. 1490 */ 1491 int 1492 kern_poll_kfds(struct thread *td, struct pollfd *kfds, u_int nfds, 1493 struct timespec *tsp, sigset_t *uset) 1494 { 1495 sbintime_t sbt, precision, tmp; 1496 time_t over; 1497 struct timespec ts; 1498 int error; 1499 1500 precision = 0; 1501 if (tsp != NULL) { 1502 if (!timespecvalid_interval(tsp)) 1503 return (EINVAL); 1504 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1505 sbt = 0; 1506 else { 1507 ts = *tsp; 1508 if (ts.tv_sec > INT32_MAX / 2) { 1509 over = ts.tv_sec - INT32_MAX / 2; 1510 ts.tv_sec -= over; 1511 } else 1512 over = 0; 1513 tmp = tstosbt(ts); 1514 precision = tmp; 1515 precision >>= tc_precexp; 1516 if (TIMESEL(&sbt, tmp)) 1517 sbt += tc_tick_sbt; 1518 sbt += tmp; 1519 } 1520 } else 1521 sbt = -1; 1522 1523 if (uset != NULL) { 1524 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1525 &td->td_oldsigmask, 0); 1526 if (error) 1527 return (error); 1528 td->td_pflags |= TDP_OLDMASK; 1529 /* 1530 * Make sure that ast() is called on return to 1531 * usermode and TDP_OLDMASK is cleared, restoring old 1532 * sigmask. 1533 */ 1534 ast_sched(td, TDA_SIGSUSPEND); 1535 } 1536 1537 seltdinit(td); 1538 /* Iterate until the timeout expires or descriptors become ready. */ 1539 for (;;) { 1540 error = pollscan(td, kfds, nfds); 1541 if (error || td->td_retval[0] != 0) 1542 break; 1543 error = seltdwait(td, sbt, precision); 1544 if (error) 1545 break; 1546 error = pollrescan(td); 1547 if (error || td->td_retval[0] != 0) 1548 break; 1549 } 1550 seltdclear(td); 1551 1552 /* poll is not restarted after signals... */ 1553 if (error == ERESTART) 1554 error = EINTR; 1555 if (error == EWOULDBLOCK) 1556 error = 0; 1557 return (error); 1558 } 1559 1560 int 1561 sys_ppoll(struct thread *td, struct ppoll_args *uap) 1562 { 1563 struct timespec ts, *tsp; 1564 sigset_t set, *ssp; 1565 int error; 1566 1567 if (uap->ts != NULL) { 1568 error = copyin(uap->ts, &ts, sizeof(ts)); 1569 if (error) 1570 return (error); 1571 tsp = &ts; 1572 } else 1573 tsp = NULL; 1574 if (uap->set != NULL) { 1575 error = copyin(uap->set, &set, sizeof(set)); 1576 if (error) 1577 return (error); 1578 ssp = &set; 1579 } else 1580 ssp = NULL; 1581 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); 1582 } 1583 1584 /* 1585 * ufds points to an array in user space. 1586 */ 1587 int 1588 kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds, 1589 struct timespec *tsp, sigset_t *set) 1590 { 1591 struct pollfd *kfds; 1592 struct pollfd stackfds[32]; 1593 int error; 1594 1595 if (kern_poll_maxfds(nfds)) 1596 return (EINVAL); 1597 if (nfds > nitems(stackfds)) 1598 kfds = mallocarray(nfds, sizeof(*kfds), M_TEMP, M_WAITOK); 1599 else 1600 kfds = stackfds; 1601 error = copyin(ufds, kfds, nfds * sizeof(*kfds)); 1602 if (error != 0) 1603 goto out; 1604 1605 error = kern_poll_kfds(td, kfds, nfds, tsp, set); 1606 if (error == 0) 1607 error = pollout(td, kfds, ufds, nfds); 1608 1609 out: 1610 if (nfds > nitems(stackfds)) 1611 free(kfds, M_TEMP); 1612 return (error); 1613 } 1614 1615 bool 1616 kern_poll_maxfds(u_int nfds) 1617 { 1618 1619 /* 1620 * This is kinda bogus. We have fd limits, but that is not 1621 * really related to the size of the pollfd array. Make sure 1622 * we let the process use at least FD_SETSIZE entries and at 1623 * least enough for the system-wide limits. We want to be reasonably 1624 * safe, but not overly restrictive. 1625 */ 1626 return (nfds > maxfilesperproc && nfds > FD_SETSIZE); 1627 } 1628 1629 static int 1630 pollrescan(struct thread *td) 1631 { 1632 struct seltd *stp; 1633 struct selfd *sfp; 1634 struct selfd *sfn; 1635 struct selinfo *si; 1636 struct filedesc *fdp; 1637 struct file *fp; 1638 struct pollfd *fd; 1639 int n, error; 1640 bool only_user; 1641 1642 n = 0; 1643 fdp = td->td_proc->p_fd; 1644 stp = td->td_sel; 1645 only_user = FILEDESC_IS_ONLY_USER(fdp); 1646 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1647 fd = (struct pollfd *)sfp->sf_cookie; 1648 si = sfp->sf_si; 1649 selfdfree(stp, sfp); 1650 /* If the selinfo wasn't cleared the event didn't fire. */ 1651 if (si != NULL) 1652 continue; 1653 if (only_user) 1654 error = fget_only_user(fdp, fd->fd, &cap_event_rights, &fp); 1655 else 1656 error = fget_unlocked(td, fd->fd, &cap_event_rights, &fp); 1657 if (__predict_false(error != 0)) { 1658 fd->revents = POLLNVAL; 1659 n++; 1660 continue; 1661 } 1662 /* 1663 * Note: backend also returns POLLHUP and 1664 * POLLERR if appropriate. 1665 */ 1666 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1667 if (only_user) 1668 fput_only_user(fdp, fp); 1669 else 1670 fdrop(fp, td); 1671 if (fd->revents != 0) 1672 n++; 1673 } 1674 stp->st_flags = 0; 1675 td->td_retval[0] = n; 1676 return (0); 1677 } 1678 1679 static int 1680 pollout(struct thread *td, struct pollfd *fds, struct pollfd *ufds, u_int nfd) 1681 { 1682 int error = 0; 1683 u_int i = 0; 1684 u_int n = 0; 1685 1686 for (i = 0; i < nfd; i++) { 1687 error = copyout(&fds->revents, &ufds->revents, 1688 sizeof(ufds->revents)); 1689 if (error) 1690 return (error); 1691 if (fds->revents != 0) 1692 n++; 1693 fds++; 1694 ufds++; 1695 } 1696 td->td_retval[0] = n; 1697 return (0); 1698 } 1699 1700 static int 1701 pollscan(struct thread *td, struct pollfd *fds, u_int nfd) 1702 { 1703 struct filedesc *fdp; 1704 struct file *fp; 1705 int i, n, error; 1706 bool only_user; 1707 1708 n = 0; 1709 fdp = td->td_proc->p_fd; 1710 only_user = FILEDESC_IS_ONLY_USER(fdp); 1711 for (i = 0; i < nfd; i++, fds++) { 1712 if (fds->fd < 0) { 1713 fds->revents = 0; 1714 continue; 1715 } 1716 if (only_user) 1717 error = fget_only_user(fdp, fds->fd, &cap_event_rights, &fp); 1718 else 1719 error = fget_unlocked(td, fds->fd, &cap_event_rights, &fp); 1720 if (__predict_false(error != 0)) { 1721 fds->revents = POLLNVAL; 1722 n++; 1723 continue; 1724 } 1725 /* 1726 * Note: backend also returns POLLHUP and 1727 * POLLERR if appropriate. 1728 */ 1729 selfdalloc(td, fds); 1730 fds->revents = fo_poll(fp, fds->events, 1731 td->td_ucred, td); 1732 if (only_user) 1733 fput_only_user(fdp, fp); 1734 else 1735 fdrop(fp, td); 1736 /* 1737 * POSIX requires POLLOUT to be never 1738 * set simultaneously with POLLHUP. 1739 */ 1740 if ((fds->revents & POLLHUP) != 0) 1741 fds->revents &= ~POLLOUT; 1742 1743 if (fds->revents != 0) 1744 n++; 1745 } 1746 td->td_retval[0] = n; 1747 return (0); 1748 } 1749 1750 /* 1751 * XXX This was created specifically to support netncp and netsmb. This 1752 * allows the caller to specify a socket to wait for events on. It returns 1753 * 0 if any events matched and an error otherwise. There is no way to 1754 * determine which events fired. 1755 */ 1756 int 1757 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1758 { 1759 struct timeval rtv; 1760 sbintime_t asbt, precision, rsbt; 1761 int error; 1762 1763 precision = 0; /* stupid gcc! */ 1764 if (tvp != NULL) { 1765 rtv = *tvp; 1766 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1767 rtv.tv_usec >= 1000000) 1768 return (EINVAL); 1769 if (!timevalisset(&rtv)) 1770 asbt = 0; 1771 else if (rtv.tv_sec <= INT32_MAX) { 1772 rsbt = tvtosbt(rtv); 1773 precision = rsbt; 1774 precision >>= tc_precexp; 1775 if (TIMESEL(&asbt, rsbt)) 1776 asbt += tc_tick_sbt; 1777 if (asbt <= SBT_MAX - rsbt) 1778 asbt += rsbt; 1779 else 1780 asbt = -1; 1781 } else 1782 asbt = -1; 1783 } else 1784 asbt = -1; 1785 seltdinit(td); 1786 /* 1787 * Iterate until the timeout expires or the socket becomes ready. 1788 */ 1789 for (;;) { 1790 selfdalloc(td, NULL); 1791 if (sopoll(so, events, NULL, td) != 0) { 1792 error = 0; 1793 break; 1794 } 1795 error = seltdwait(td, asbt, precision); 1796 if (error) 1797 break; 1798 } 1799 seltdclear(td); 1800 /* XXX Duplicates ncp/smb behavior. */ 1801 if (error == ERESTART) 1802 error = 0; 1803 return (error); 1804 } 1805 1806 /* 1807 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1808 * have two select sets, one for read and another for write. 1809 */ 1810 static void 1811 selfdalloc(struct thread *td, void *cookie) 1812 { 1813 struct seltd *stp; 1814 1815 stp = td->td_sel; 1816 if (stp->st_free1 == NULL) 1817 stp->st_free1 = malloc(sizeof(*stp->st_free1), M_SELFD, M_WAITOK|M_ZERO); 1818 stp->st_free1->sf_td = stp; 1819 stp->st_free1->sf_cookie = cookie; 1820 if (stp->st_free2 == NULL) 1821 stp->st_free2 = malloc(sizeof(*stp->st_free2), M_SELFD, M_WAITOK|M_ZERO); 1822 stp->st_free2->sf_td = stp; 1823 stp->st_free2->sf_cookie = cookie; 1824 } 1825 1826 static void 1827 selfdfree(struct seltd *stp, struct selfd *sfp) 1828 { 1829 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1830 /* 1831 * Paired with doselwakeup. 1832 */ 1833 if (atomic_load_acq_ptr((uintptr_t *)&sfp->sf_si) != (uintptr_t)NULL) { 1834 mtx_lock(sfp->sf_mtx); 1835 if (sfp->sf_si != NULL) { 1836 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1837 } 1838 mtx_unlock(sfp->sf_mtx); 1839 } 1840 free(sfp, M_SELFD); 1841 } 1842 1843 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1844 void 1845 seldrain(struct selinfo *sip) 1846 { 1847 1848 /* 1849 * This feature is already provided by doselwakeup(), thus it is 1850 * enough to go for it. 1851 * Eventually, the context, should take care to avoid races 1852 * between thread calling select()/poll() and file descriptor 1853 * detaching, but, again, the races are just the same as 1854 * selwakeup(). 1855 */ 1856 doselwakeup(sip, -1); 1857 } 1858 1859 /* 1860 * Record a select request. 1861 */ 1862 void 1863 selrecord(struct thread *selector, struct selinfo *sip) 1864 { 1865 struct selfd *sfp; 1866 struct seltd *stp; 1867 struct mtx *mtxp; 1868 1869 stp = selector->td_sel; 1870 /* 1871 * Don't record when doing a rescan. 1872 */ 1873 if (stp->st_flags & SELTD_RESCAN) 1874 return; 1875 /* 1876 * Grab one of the preallocated descriptors. 1877 */ 1878 sfp = NULL; 1879 if ((sfp = stp->st_free1) != NULL) 1880 stp->st_free1 = NULL; 1881 else if ((sfp = stp->st_free2) != NULL) 1882 stp->st_free2 = NULL; 1883 else 1884 panic("selrecord: No free selfd on selq"); 1885 mtxp = sip->si_mtx; 1886 if (mtxp == NULL) 1887 mtxp = mtx_pool_find(mtxpool_select, sip); 1888 /* 1889 * Initialize the sfp and queue it in the thread. 1890 */ 1891 sfp->sf_si = sip; 1892 sfp->sf_mtx = mtxp; 1893 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1894 /* 1895 * Now that we've locked the sip, check for initialization. 1896 */ 1897 mtx_lock(mtxp); 1898 if (sip->si_mtx == NULL) { 1899 sip->si_mtx = mtxp; 1900 TAILQ_INIT(&sip->si_tdlist); 1901 } 1902 /* 1903 * Add this thread to the list of selfds listening on this selinfo. 1904 */ 1905 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1906 mtx_unlock(sip->si_mtx); 1907 } 1908 1909 /* Wake up a selecting thread. */ 1910 void 1911 selwakeup(struct selinfo *sip) 1912 { 1913 doselwakeup(sip, -1); 1914 } 1915 1916 /* Wake up a selecting thread, and set its priority. */ 1917 void 1918 selwakeuppri(struct selinfo *sip, int pri) 1919 { 1920 doselwakeup(sip, pri); 1921 } 1922 1923 /* 1924 * Do a wakeup when a selectable event occurs. 1925 */ 1926 static void 1927 doselwakeup(struct selinfo *sip, int pri) 1928 { 1929 struct selfd *sfp; 1930 struct selfd *sfn; 1931 struct seltd *stp; 1932 1933 /* If it's not initialized there can't be any waiters. */ 1934 if (sip->si_mtx == NULL) 1935 return; 1936 /* 1937 * Locking the selinfo locks all selfds associated with it. 1938 */ 1939 mtx_lock(sip->si_mtx); 1940 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1941 /* 1942 * Once we remove this sfp from the list and clear the 1943 * sf_si seltdclear will know to ignore this si. 1944 */ 1945 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1946 stp = sfp->sf_td; 1947 mtx_lock(&stp->st_mtx); 1948 stp->st_flags |= SELTD_PENDING; 1949 cv_broadcastpri(&stp->st_wait, pri); 1950 mtx_unlock(&stp->st_mtx); 1951 /* 1952 * Paired with selfdfree. 1953 * 1954 * Storing this only after the wakeup provides an invariant that 1955 * stp is not used after selfdfree returns. 1956 */ 1957 atomic_store_rel_ptr((uintptr_t *)&sfp->sf_si, (uintptr_t)NULL); 1958 } 1959 mtx_unlock(sip->si_mtx); 1960 } 1961 1962 static void 1963 seltdinit(struct thread *td) 1964 { 1965 struct seltd *stp; 1966 1967 stp = td->td_sel; 1968 if (stp != NULL) { 1969 MPASS(stp->st_flags == 0); 1970 MPASS(STAILQ_EMPTY(&stp->st_selq)); 1971 return; 1972 } 1973 stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1974 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1975 cv_init(&stp->st_wait, "select"); 1976 stp->st_flags = 0; 1977 STAILQ_INIT(&stp->st_selq); 1978 td->td_sel = stp; 1979 } 1980 1981 static int 1982 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1983 { 1984 struct seltd *stp; 1985 int error; 1986 1987 stp = td->td_sel; 1988 /* 1989 * An event of interest may occur while we do not hold the seltd 1990 * locked so check the pending flag before we sleep. 1991 */ 1992 mtx_lock(&stp->st_mtx); 1993 /* 1994 * Any further calls to selrecord will be a rescan. 1995 */ 1996 stp->st_flags |= SELTD_RESCAN; 1997 if (stp->st_flags & SELTD_PENDING) { 1998 mtx_unlock(&stp->st_mtx); 1999 return (0); 2000 } 2001 if (sbt == 0) 2002 error = EWOULDBLOCK; 2003 else if (sbt != -1) 2004 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 2005 sbt, precision, C_ABSOLUTE); 2006 else 2007 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 2008 mtx_unlock(&stp->st_mtx); 2009 2010 return (error); 2011 } 2012 2013 void 2014 seltdfini(struct thread *td) 2015 { 2016 struct seltd *stp; 2017 2018 stp = td->td_sel; 2019 if (stp == NULL) 2020 return; 2021 MPASS(stp->st_flags == 0); 2022 MPASS(STAILQ_EMPTY(&stp->st_selq)); 2023 if (stp->st_free1) 2024 free(stp->st_free1, M_SELFD); 2025 if (stp->st_free2) 2026 free(stp->st_free2, M_SELFD); 2027 td->td_sel = NULL; 2028 cv_destroy(&stp->st_wait); 2029 mtx_destroy(&stp->st_mtx); 2030 free(stp, M_SELECT); 2031 } 2032 2033 /* 2034 * Remove the references to the thread from all of the objects we were 2035 * polling. 2036 */ 2037 static void 2038 seltdclear(struct thread *td) 2039 { 2040 struct seltd *stp; 2041 struct selfd *sfp; 2042 struct selfd *sfn; 2043 2044 stp = td->td_sel; 2045 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 2046 selfdfree(stp, sfp); 2047 stp->st_flags = 0; 2048 } 2049 2050 static void selectinit(void *); 2051 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 2052 static void 2053 selectinit(void *dummy __unused) 2054 { 2055 2056 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 2057 } 2058 2059 /* 2060 * Set up a syscall return value that follows the convention specified for 2061 * posix_* functions. 2062 */ 2063 int 2064 kern_posix_error(struct thread *td, int error) 2065 { 2066 2067 if (error <= 0) 2068 return (error); 2069 td->td_errno = error; 2070 td->td_pflags |= TDP_NERRNO; 2071 td->td_retval[0] = error; 2072 return (0); 2073 } 2074