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 37 #include <sys/cdefs.h> 38 #include "opt_capsicum.h" 39 #include "opt_ktrace.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/sysproto.h> 44 #include <sys/capsicum.h> 45 #include <sys/filedesc.h> 46 #include <sys/filio.h> 47 #include <sys/fcntl.h> 48 #include <sys/file.h> 49 #include <sys/lock.h> 50 #include <sys/proc.h> 51 #include <sys/signalvar.h> 52 #include <sys/socketvar.h> 53 #include <sys/uio.h> 54 #include <sys/eventfd.h> 55 #include <sys/kernel.h> 56 #include <sys/ktr.h> 57 #include <sys/limits.h> 58 #include <sys/malloc.h> 59 #include <sys/poll.h> 60 #include <sys/resourcevar.h> 61 #include <sys/selinfo.h> 62 #include <sys/sleepqueue.h> 63 #include <sys/specialfd.h> 64 #include <sys/syscallsubr.h> 65 #include <sys/sysctl.h> 66 #include <sys/sysent.h> 67 #include <sys/vnode.h> 68 #include <sys/unistd.h> 69 #include <sys/bio.h> 70 #include <sys/buf.h> 71 #include <sys/condvar.h> 72 #ifdef KTRACE 73 #include <sys/ktrace.h> 74 #endif 75 76 #include <security/audit/audit.h> 77 78 /* 79 * The following macro defines how many bytes will be allocated from 80 * the stack instead of memory allocated when passing the IOCTL data 81 * structures from userspace and to the kernel. Some IOCTLs having 82 * small data structures are used very frequently and this small 83 * buffer on the stack gives a significant speedup improvement for 84 * those requests. The value of this define should be greater or equal 85 * to 64 bytes and should also be power of two. The data structure is 86 * currently hard-aligned to a 8-byte boundary on the stack. This 87 * should currently be sufficient for all supported platforms. 88 */ 89 #define SYS_IOCTL_SMALL_SIZE 128 /* bytes */ 90 #define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */ 91 92 #ifdef __LP64__ 93 static int iosize_max_clamp = 0; 94 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, 95 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); 96 static int devfs_iosize_max_clamp = 1; 97 SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW, 98 &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices"); 99 #endif 100 101 /* 102 * Assert that the return value of read(2) and write(2) syscalls fits 103 * into a register. If not, an architecture will need to provide the 104 * usermode wrappers to reconstruct the result. 105 */ 106 CTASSERT(sizeof(register_t) >= sizeof(size_t)); 107 108 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 109 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); 110 MALLOC_DEFINE(M_IOV, "iov", "large iov's"); 111 112 static int pollout(struct thread *, struct pollfd *, struct pollfd *, 113 u_int); 114 static int pollscan(struct thread *, struct pollfd *, u_int); 115 static int pollrescan(struct thread *); 116 static int selscan(struct thread *, fd_mask **, fd_mask **, int); 117 static int selrescan(struct thread *, fd_mask **, fd_mask **); 118 static void selfdalloc(struct thread *, void *); 119 static void selfdfree(struct seltd *, struct selfd *); 120 static int dofileread(struct thread *, int, struct file *, struct uio *, 121 off_t, int); 122 static int dofilewrite(struct thread *, int, struct file *, struct uio *, 123 off_t, int); 124 static void doselwakeup(struct selinfo *, int); 125 static void seltdinit(struct thread *); 126 static int seltdwait(struct thread *, sbintime_t, sbintime_t); 127 static void seltdclear(struct thread *); 128 129 /* 130 * One seltd per-thread allocated on demand as needed. 131 * 132 * t - protected by st_mtx 133 * k - Only accessed by curthread or read-only 134 */ 135 struct seltd { 136 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ 137 struct selfd *st_free1; /* (k) free fd for read set. */ 138 struct selfd *st_free2; /* (k) free fd for write set. */ 139 struct mtx st_mtx; /* Protects struct seltd */ 140 struct cv st_wait; /* (t) Wait channel. */ 141 int st_flags; /* (t) SELTD_ flags. */ 142 }; 143 144 #define SELTD_PENDING 0x0001 /* We have pending events. */ 145 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */ 146 147 /* 148 * One selfd allocated per-thread per-file-descriptor. 149 * f - protected by sf_mtx 150 */ 151 struct selfd { 152 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ 153 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ 154 struct selinfo *sf_si; /* (f) selinfo when linked. */ 155 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ 156 struct seltd *sf_td; /* (k) owning seltd. */ 157 void *sf_cookie; /* (k) fd or pollfd. */ 158 }; 159 160 MALLOC_DEFINE(M_SELFD, "selfd", "selfd"); 161 static struct mtx_pool *mtxpool_select; 162 163 #ifdef __LP64__ 164 size_t 165 devfs_iosize_max(void) 166 { 167 168 return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 169 INT_MAX : SSIZE_MAX); 170 } 171 172 size_t 173 iosize_max(void) 174 { 175 176 return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 177 INT_MAX : SSIZE_MAX); 178 } 179 #endif 180 181 #ifndef _SYS_SYSPROTO_H_ 182 struct read_args { 183 int fd; 184 void *buf; 185 size_t nbyte; 186 }; 187 #endif 188 int 189 sys_read(struct thread *td, struct read_args *uap) 190 { 191 struct uio auio; 192 struct iovec aiov; 193 int error; 194 195 if (uap->nbyte > IOSIZE_MAX) 196 return (EINVAL); 197 aiov.iov_base = uap->buf; 198 aiov.iov_len = uap->nbyte; 199 auio.uio_iov = &aiov; 200 auio.uio_iovcnt = 1; 201 auio.uio_resid = uap->nbyte; 202 auio.uio_segflg = UIO_USERSPACE; 203 error = kern_readv(td, uap->fd, &auio); 204 return (error); 205 } 206 207 /* 208 * Positioned read system call 209 */ 210 #ifndef _SYS_SYSPROTO_H_ 211 struct pread_args { 212 int fd; 213 void *buf; 214 size_t nbyte; 215 int pad; 216 off_t offset; 217 }; 218 #endif 219 int 220 sys_pread(struct thread *td, struct pread_args *uap) 221 { 222 223 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 224 } 225 226 int 227 kern_pread(struct thread *td, int fd, void *buf, size_t nbyte, off_t offset) 228 { 229 struct uio auio; 230 struct iovec aiov; 231 int error; 232 233 if (nbyte > IOSIZE_MAX) 234 return (EINVAL); 235 aiov.iov_base = buf; 236 aiov.iov_len = nbyte; 237 auio.uio_iov = &aiov; 238 auio.uio_iovcnt = 1; 239 auio.uio_resid = nbyte; 240 auio.uio_segflg = UIO_USERSPACE; 241 error = kern_preadv(td, fd, &auio, offset); 242 return (error); 243 } 244 245 #if defined(COMPAT_FREEBSD6) 246 int 247 freebsd6_pread(struct thread *td, struct freebsd6_pread_args *uap) 248 { 249 250 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 251 } 252 #endif 253 254 /* 255 * Scatter read system call. 256 */ 257 #ifndef _SYS_SYSPROTO_H_ 258 struct readv_args { 259 int fd; 260 struct iovec *iovp; 261 u_int iovcnt; 262 }; 263 #endif 264 int 265 sys_readv(struct thread *td, struct readv_args *uap) 266 { 267 struct uio *auio; 268 int error; 269 270 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 271 if (error) 272 return (error); 273 error = kern_readv(td, uap->fd, auio); 274 freeuio(auio); 275 return (error); 276 } 277 278 int 279 kern_readv(struct thread *td, int fd, struct uio *auio) 280 { 281 struct file *fp; 282 int error; 283 284 error = fget_read(td, fd, &cap_read_rights, &fp); 285 if (error) 286 return (error); 287 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 288 fdrop(fp, td); 289 return (error); 290 } 291 292 /* 293 * Scatter positioned read system call. 294 */ 295 #ifndef _SYS_SYSPROTO_H_ 296 struct preadv_args { 297 int fd; 298 struct iovec *iovp; 299 u_int iovcnt; 300 off_t offset; 301 }; 302 #endif 303 int 304 sys_preadv(struct thread *td, struct preadv_args *uap) 305 { 306 struct uio *auio; 307 int error; 308 309 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 310 if (error) 311 return (error); 312 error = kern_preadv(td, uap->fd, auio, uap->offset); 313 freeuio(auio); 314 return (error); 315 } 316 317 int 318 kern_preadv(struct thread *td, int fd, struct uio *auio, off_t offset) 319 { 320 struct file *fp; 321 int error; 322 323 error = fget_read(td, fd, &cap_pread_rights, &fp); 324 if (error) 325 return (error); 326 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 327 error = ESPIPE; 328 else if (offset < 0 && 329 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 330 error = EINVAL; 331 else 332 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 333 fdrop(fp, td); 334 return (error); 335 } 336 337 /* 338 * Common code for readv and preadv that reads data in 339 * from a file using the passed in uio, offset, and flags. 340 */ 341 static int 342 dofileread(struct thread *td, int fd, struct file *fp, struct uio *auio, 343 off_t offset, int flags) 344 { 345 ssize_t cnt; 346 int error; 347 #ifdef KTRACE 348 struct uio *ktruio = NULL; 349 #endif 350 351 AUDIT_ARG_FD(fd); 352 353 /* Finish zero length reads right here */ 354 if (auio->uio_resid == 0) { 355 td->td_retval[0] = 0; 356 return (0); 357 } 358 auio->uio_rw = UIO_READ; 359 auio->uio_offset = offset; 360 auio->uio_td = td; 361 #ifdef KTRACE 362 if (KTRPOINT(td, KTR_GENIO)) 363 ktruio = cloneuio(auio); 364 #endif 365 cnt = auio->uio_resid; 366 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 367 if (auio->uio_resid != cnt && (error == ERESTART || 368 error == EINTR || error == EWOULDBLOCK)) 369 error = 0; 370 } 371 cnt -= auio->uio_resid; 372 #ifdef KTRACE 373 if (ktruio != NULL) { 374 ktruio->uio_resid = cnt; 375 ktrgenio(fd, UIO_READ, ktruio, error); 376 } 377 #endif 378 td->td_retval[0] = cnt; 379 return (error); 380 } 381 382 #ifndef _SYS_SYSPROTO_H_ 383 struct write_args { 384 int fd; 385 const void *buf; 386 size_t nbyte; 387 }; 388 #endif 389 int 390 sys_write(struct thread *td, struct write_args *uap) 391 { 392 struct uio auio; 393 struct iovec aiov; 394 int error; 395 396 if (uap->nbyte > IOSIZE_MAX) 397 return (EINVAL); 398 aiov.iov_base = (void *)(uintptr_t)uap->buf; 399 aiov.iov_len = uap->nbyte; 400 auio.uio_iov = &aiov; 401 auio.uio_iovcnt = 1; 402 auio.uio_resid = uap->nbyte; 403 auio.uio_segflg = UIO_USERSPACE; 404 error = kern_writev(td, uap->fd, &auio); 405 return (error); 406 } 407 408 /* 409 * Positioned write system call. 410 */ 411 #ifndef _SYS_SYSPROTO_H_ 412 struct pwrite_args { 413 int fd; 414 const void *buf; 415 size_t nbyte; 416 int pad; 417 off_t offset; 418 }; 419 #endif 420 int 421 sys_pwrite(struct thread *td, struct pwrite_args *uap) 422 { 423 424 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 425 } 426 427 int 428 kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte, 429 off_t offset) 430 { 431 struct uio auio; 432 struct iovec aiov; 433 int error; 434 435 if (nbyte > IOSIZE_MAX) 436 return (EINVAL); 437 aiov.iov_base = (void *)(uintptr_t)buf; 438 aiov.iov_len = nbyte; 439 auio.uio_iov = &aiov; 440 auio.uio_iovcnt = 1; 441 auio.uio_resid = nbyte; 442 auio.uio_segflg = UIO_USERSPACE; 443 error = kern_pwritev(td, fd, &auio, offset); 444 return (error); 445 } 446 447 #if defined(COMPAT_FREEBSD6) 448 int 449 freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap) 450 { 451 452 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 453 } 454 #endif 455 456 /* 457 * Gather write system call. 458 */ 459 #ifndef _SYS_SYSPROTO_H_ 460 struct writev_args { 461 int fd; 462 struct iovec *iovp; 463 u_int iovcnt; 464 }; 465 #endif 466 int 467 sys_writev(struct thread *td, struct writev_args *uap) 468 { 469 struct uio *auio; 470 int error; 471 472 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 473 if (error) 474 return (error); 475 error = kern_writev(td, uap->fd, auio); 476 freeuio(auio); 477 return (error); 478 } 479 480 int 481 kern_writev(struct thread *td, int fd, struct uio *auio) 482 { 483 struct file *fp; 484 int error; 485 486 error = fget_write(td, fd, &cap_write_rights, &fp); 487 if (error) 488 return (error); 489 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 490 fdrop(fp, td); 491 return (error); 492 } 493 494 /* 495 * Gather positioned write system call. 496 */ 497 #ifndef _SYS_SYSPROTO_H_ 498 struct pwritev_args { 499 int fd; 500 struct iovec *iovp; 501 u_int iovcnt; 502 off_t offset; 503 }; 504 #endif 505 int 506 sys_pwritev(struct thread *td, struct pwritev_args *uap) 507 { 508 struct uio *auio; 509 int error; 510 511 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 512 if (error) 513 return (error); 514 error = kern_pwritev(td, uap->fd, auio, uap->offset); 515 freeuio(auio); 516 return (error); 517 } 518 519 int 520 kern_pwritev(struct thread *td, int fd, struct uio *auio, off_t offset) 521 { 522 struct file *fp; 523 int error; 524 525 error = fget_write(td, fd, &cap_pwrite_rights, &fp); 526 if (error) 527 return (error); 528 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 529 error = ESPIPE; 530 else if (offset < 0 && 531 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 532 error = EINVAL; 533 else 534 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 535 fdrop(fp, td); 536 return (error); 537 } 538 539 /* 540 * Common code for writev and pwritev that writes data to 541 * a file using the passed in uio, offset, and flags. 542 */ 543 static int 544 dofilewrite(struct thread *td, int fd, struct file *fp, struct uio *auio, 545 off_t offset, int flags) 546 { 547 ssize_t cnt; 548 int error; 549 #ifdef KTRACE 550 struct uio *ktruio = NULL; 551 #endif 552 553 AUDIT_ARG_FD(fd); 554 auio->uio_rw = UIO_WRITE; 555 auio->uio_td = td; 556 auio->uio_offset = offset; 557 #ifdef KTRACE 558 if (KTRPOINT(td, KTR_GENIO)) 559 ktruio = cloneuio(auio); 560 #endif 561 cnt = auio->uio_resid; 562 error = fo_write(fp, auio, td->td_ucred, flags, td); 563 /* 564 * Socket layer is responsible for special error handling, 565 * see sousrsend(). 566 */ 567 if (error != 0 && fp->f_type != DTYPE_SOCKET) { 568 if (auio->uio_resid != cnt && (error == ERESTART || 569 error == EINTR || error == EWOULDBLOCK)) 570 error = 0; 571 if (error == EPIPE) { 572 PROC_LOCK(td->td_proc); 573 tdsignal(td, SIGPIPE); 574 PROC_UNLOCK(td->td_proc); 575 } 576 } 577 cnt -= auio->uio_resid; 578 #ifdef KTRACE 579 if (ktruio != NULL) { 580 if (error == 0) 581 ktruio->uio_resid = cnt; 582 ktrgenio(fd, UIO_WRITE, ktruio, error); 583 } 584 #endif 585 td->td_retval[0] = cnt; 586 return (error); 587 } 588 589 /* 590 * Truncate a file given a file descriptor. 591 * 592 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 593 * descriptor isn't writable. 594 */ 595 int 596 kern_ftruncate(struct thread *td, int fd, off_t length) 597 { 598 struct file *fp; 599 int error; 600 601 AUDIT_ARG_FD(fd); 602 if (length < 0) 603 return (EINVAL); 604 error = fget(td, fd, &cap_ftruncate_rights, &fp); 605 if (error) 606 return (error); 607 AUDIT_ARG_FILE(td->td_proc, fp); 608 if (!(fp->f_flag & FWRITE)) { 609 fdrop(fp, td); 610 return (EINVAL); 611 } 612 error = fo_truncate(fp, length, td->td_ucred, td); 613 fdrop(fp, td); 614 return (error); 615 } 616 617 #ifndef _SYS_SYSPROTO_H_ 618 struct ftruncate_args { 619 int fd; 620 int pad; 621 off_t length; 622 }; 623 #endif 624 int 625 sys_ftruncate(struct thread *td, struct ftruncate_args *uap) 626 { 627 628 return (kern_ftruncate(td, uap->fd, uap->length)); 629 } 630 631 #if defined(COMPAT_43) 632 #ifndef _SYS_SYSPROTO_H_ 633 struct oftruncate_args { 634 int fd; 635 long length; 636 }; 637 #endif 638 int 639 oftruncate(struct thread *td, struct oftruncate_args *uap) 640 { 641 642 return (kern_ftruncate(td, uap->fd, uap->length)); 643 } 644 #endif /* COMPAT_43 */ 645 646 #ifndef _SYS_SYSPROTO_H_ 647 struct ioctl_args { 648 int fd; 649 u_long com; 650 caddr_t data; 651 }; 652 #endif 653 /* ARGSUSED */ 654 int 655 sys_ioctl(struct thread *td, struct ioctl_args *uap) 656 { 657 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); 658 uint32_t com; 659 int arg, error; 660 u_int size; 661 caddr_t data; 662 663 #ifdef INVARIANTS 664 if (uap->com > 0xffffffff) { 665 printf( 666 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 667 td->td_proc->p_pid, td->td_name, uap->com); 668 } 669 #endif 670 com = (uint32_t)uap->com; 671 672 /* 673 * Interpret high order word to find amount of data to be 674 * copied to/from the user's address space. 675 */ 676 size = IOCPARM_LEN(com); 677 if ((size > IOCPARM_MAX) || 678 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 679 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 680 ((com & IOC_OUT) && size == 0) || 681 #else 682 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 683 #endif 684 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 685 return (ENOTTY); 686 687 if (size > 0) { 688 if (com & IOC_VOID) { 689 /* Integer argument. */ 690 arg = (intptr_t)uap->data; 691 data = (void *)&arg; 692 size = 0; 693 } else { 694 if (size > SYS_IOCTL_SMALL_SIZE) 695 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 696 else 697 data = smalldata; 698 } 699 } else 700 data = (void *)&uap->data; 701 if (com & IOC_IN) { 702 error = copyin(uap->data, data, (u_int)size); 703 if (error != 0) 704 goto out; 705 } else if (com & IOC_OUT) { 706 /* 707 * Zero the buffer so the user always 708 * gets back something deterministic. 709 */ 710 bzero(data, size); 711 } 712 713 error = kern_ioctl(td, uap->fd, com, data); 714 715 if (error == 0 && (com & IOC_OUT)) 716 error = copyout(data, uap->data, (u_int)size); 717 718 out: 719 if (size > SYS_IOCTL_SMALL_SIZE) 720 free(data, M_IOCTLOPS); 721 return (error); 722 } 723 724 int 725 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 726 { 727 struct file *fp; 728 struct filedesc *fdp; 729 int error, tmp, locked; 730 731 AUDIT_ARG_FD(fd); 732 AUDIT_ARG_CMD(com); 733 734 fdp = td->td_proc->p_fd; 735 736 switch (com) { 737 case FIONCLEX: 738 case FIOCLEX: 739 FILEDESC_XLOCK(fdp); 740 locked = LA_XLOCKED; 741 break; 742 default: 743 #ifdef CAPABILITIES 744 FILEDESC_SLOCK(fdp); 745 locked = LA_SLOCKED; 746 #else 747 locked = LA_UNLOCKED; 748 #endif 749 break; 750 } 751 752 #ifdef CAPABILITIES 753 if ((fp = fget_noref(fdp, fd)) == NULL) { 754 error = EBADF; 755 goto out; 756 } 757 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 758 fp = NULL; /* fhold() was not called yet */ 759 goto out; 760 } 761 if (!fhold(fp)) { 762 error = EBADF; 763 fp = NULL; 764 goto out; 765 } 766 if (locked == LA_SLOCKED) { 767 FILEDESC_SUNLOCK(fdp); 768 locked = LA_UNLOCKED; 769 } 770 #else 771 error = fget(td, fd, &cap_ioctl_rights, &fp); 772 if (error != 0) { 773 fp = NULL; 774 goto out; 775 } 776 #endif 777 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 778 error = EBADF; 779 goto out; 780 } 781 782 switch (com) { 783 case FIONCLEX: 784 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 785 goto out; 786 case FIOCLEX: 787 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 788 goto out; 789 case FIONBIO: 790 if ((tmp = *(int *)data)) 791 atomic_set_int(&fp->f_flag, FNONBLOCK); 792 else 793 atomic_clear_int(&fp->f_flag, FNONBLOCK); 794 data = (void *)&tmp; 795 break; 796 case FIOASYNC: 797 if ((tmp = *(int *)data)) 798 atomic_set_int(&fp->f_flag, FASYNC); 799 else 800 atomic_clear_int(&fp->f_flag, FASYNC); 801 data = (void *)&tmp; 802 break; 803 } 804 805 error = fo_ioctl(fp, com, data, td->td_ucred, td); 806 out: 807 switch (locked) { 808 case LA_XLOCKED: 809 FILEDESC_XUNLOCK(fdp); 810 break; 811 #ifdef CAPABILITIES 812 case LA_SLOCKED: 813 FILEDESC_SUNLOCK(fdp); 814 break; 815 #endif 816 default: 817 FILEDESC_UNLOCK_ASSERT(fdp); 818 break; 819 } 820 if (fp != NULL) 821 fdrop(fp, td); 822 return (error); 823 } 824 825 int 826 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap) 827 { 828 int error; 829 830 error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len); 831 return (kern_posix_error(td, error)); 832 } 833 834 int 835 kern_posix_fallocate(struct thread *td, int fd, off_t offset, off_t len) 836 { 837 struct file *fp; 838 int error; 839 840 AUDIT_ARG_FD(fd); 841 if (offset < 0 || len <= 0) 842 return (EINVAL); 843 /* Check for wrap. */ 844 if (offset > OFF_MAX - len) 845 return (EFBIG); 846 AUDIT_ARG_FD(fd); 847 error = fget(td, fd, &cap_pwrite_rights, &fp); 848 if (error != 0) 849 return (error); 850 AUDIT_ARG_FILE(td->td_proc, fp); 851 if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) { 852 error = ESPIPE; 853 goto out; 854 } 855 if ((fp->f_flag & FWRITE) == 0) { 856 error = EBADF; 857 goto out; 858 } 859 860 error = fo_fallocate(fp, offset, len, td); 861 out: 862 fdrop(fp, td); 863 return (error); 864 } 865 866 int 867 sys_fspacectl(struct thread *td, struct fspacectl_args *uap) 868 { 869 struct spacectl_range rqsr, rmsr; 870 int error, cerror; 871 872 error = copyin(uap->rqsr, &rqsr, sizeof(rqsr)); 873 if (error != 0) 874 return (error); 875 876 error = kern_fspacectl(td, uap->fd, uap->cmd, &rqsr, uap->flags, 877 &rmsr); 878 if (uap->rmsr != NULL) { 879 cerror = copyout(&rmsr, uap->rmsr, sizeof(rmsr)); 880 if (error == 0) 881 error = cerror; 882 } 883 return (error); 884 } 885 886 int 887 kern_fspacectl(struct thread *td, int fd, int cmd, 888 const struct spacectl_range *rqsr, int flags, struct spacectl_range *rmsrp) 889 { 890 struct file *fp; 891 struct spacectl_range rmsr; 892 int error; 893 894 AUDIT_ARG_FD(fd); 895 AUDIT_ARG_CMD(cmd); 896 AUDIT_ARG_FFLAGS(flags); 897 898 if (rqsr == NULL) 899 return (EINVAL); 900 rmsr = *rqsr; 901 if (rmsrp != NULL) 902 *rmsrp = rmsr; 903 904 if (cmd != SPACECTL_DEALLOC || 905 rqsr->r_offset < 0 || rqsr->r_len <= 0 || 906 rqsr->r_offset > OFF_MAX - rqsr->r_len || 907 (flags & ~SPACECTL_F_SUPPORTED) != 0) 908 return (EINVAL); 909 910 error = fget_write(td, fd, &cap_pwrite_rights, &fp); 911 if (error != 0) 912 return (error); 913 AUDIT_ARG_FILE(td->td_proc, fp); 914 if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) { 915 error = ESPIPE; 916 goto out; 917 } 918 if ((fp->f_flag & FWRITE) == 0) { 919 error = EBADF; 920 goto out; 921 } 922 923 error = fo_fspacectl(fp, cmd, &rmsr.r_offset, &rmsr.r_len, flags, 924 td->td_ucred, td); 925 /* fspacectl is not restarted after signals if the file is modified. */ 926 if (rmsr.r_len != rqsr->r_len && (error == ERESTART || 927 error == EINTR || error == EWOULDBLOCK)) 928 error = 0; 929 if (rmsrp != NULL) 930 *rmsrp = rmsr; 931 out: 932 fdrop(fp, td); 933 return (error); 934 } 935 936 int 937 kern_specialfd(struct thread *td, int type, void *arg) 938 { 939 struct file *fp; 940 struct specialfd_eventfd *ae; 941 int error, fd, fflags; 942 943 fflags = 0; 944 error = falloc_noinstall(td, &fp); 945 if (error != 0) 946 return (error); 947 948 switch (type) { 949 case SPECIALFD_EVENTFD: 950 ae = arg; 951 if ((ae->flags & EFD_CLOEXEC) != 0) 952 fflags |= O_CLOEXEC; 953 error = eventfd_create_file(td, fp, ae->initval, ae->flags); 954 break; 955 default: 956 error = EINVAL; 957 break; 958 } 959 960 if (error == 0) 961 error = finstall(td, fp, &fd, fflags, NULL); 962 fdrop(fp, td); 963 if (error == 0) 964 td->td_retval[0] = fd; 965 return (error); 966 } 967 968 int 969 sys___specialfd(struct thread *td, struct __specialfd_args *args) 970 { 971 struct specialfd_eventfd ae; 972 int error; 973 974 switch (args->type) { 975 case SPECIALFD_EVENTFD: 976 if (args->len != sizeof(struct specialfd_eventfd)) { 977 error = EINVAL; 978 break; 979 } 980 error = copyin(args->req, &ae, sizeof(ae)); 981 if (error != 0) 982 break; 983 if ((ae.flags & ~(EFD_CLOEXEC | EFD_NONBLOCK | 984 EFD_SEMAPHORE)) != 0) { 985 error = EINVAL; 986 break; 987 } 988 error = kern_specialfd(td, args->type, &ae); 989 break; 990 default: 991 error = EINVAL; 992 break; 993 } 994 return (error); 995 } 996 997 int 998 poll_no_poll(int events) 999 { 1000 /* 1001 * Return true for read/write. If the user asked for something 1002 * special, return POLLNVAL, so that clients have a way of 1003 * determining reliably whether or not the extended 1004 * functionality is present without hard-coding knowledge 1005 * of specific filesystem implementations. 1006 */ 1007 if (events & ~POLLSTANDARD) 1008 return (POLLNVAL); 1009 1010 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 1011 } 1012 1013 int 1014 sys_pselect(struct thread *td, struct pselect_args *uap) 1015 { 1016 struct timespec ts; 1017 struct timeval tv, *tvp; 1018 sigset_t set, *uset; 1019 int error; 1020 1021 if (uap->ts != NULL) { 1022 error = copyin(uap->ts, &ts, sizeof(ts)); 1023 if (error != 0) 1024 return (error); 1025 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1026 tvp = &tv; 1027 } else 1028 tvp = NULL; 1029 if (uap->sm != NULL) { 1030 error = copyin(uap->sm, &set, sizeof(set)); 1031 if (error != 0) 1032 return (error); 1033 uset = &set; 1034 } else 1035 uset = NULL; 1036 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 1037 uset, NFDBITS)); 1038 } 1039 1040 int 1041 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 1042 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 1043 { 1044 int error; 1045 1046 if (uset != NULL) { 1047 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1048 &td->td_oldsigmask, 0); 1049 if (error != 0) 1050 return (error); 1051 td->td_pflags |= TDP_OLDMASK; 1052 /* 1053 * Make sure that ast() is called on return to 1054 * usermode and TDP_OLDMASK is cleared, restoring old 1055 * sigmask. 1056 */ 1057 ast_sched(td, TDA_SIGSUSPEND); 1058 } 1059 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 1060 return (error); 1061 } 1062 1063 #ifndef _SYS_SYSPROTO_H_ 1064 struct select_args { 1065 int nd; 1066 fd_set *in, *ou, *ex; 1067 struct timeval *tv; 1068 }; 1069 #endif 1070 int 1071 sys_select(struct thread *td, struct select_args *uap) 1072 { 1073 struct timeval tv, *tvp; 1074 int error; 1075 1076 if (uap->tv != NULL) { 1077 error = copyin(uap->tv, &tv, sizeof(tv)); 1078 if (error) 1079 return (error); 1080 tvp = &tv; 1081 } else 1082 tvp = NULL; 1083 1084 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 1085 NFDBITS)); 1086 } 1087 1088 /* 1089 * In the unlikely case when user specified n greater then the last 1090 * open file descriptor, check that no bits are set after the last 1091 * valid fd. We must return EBADF if any is set. 1092 * 1093 * There are applications that rely on the behaviour. 1094 * 1095 * nd is fd_nfiles. 1096 */ 1097 static int 1098 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 1099 { 1100 char *addr, *oaddr; 1101 int b, i, res; 1102 uint8_t bits; 1103 1104 if (nd >= ndu || fd_in == NULL) 1105 return (0); 1106 1107 oaddr = NULL; 1108 bits = 0; /* silence gcc */ 1109 for (i = nd; i < ndu; i++) { 1110 b = i / NBBY; 1111 #if BYTE_ORDER == LITTLE_ENDIAN 1112 addr = (char *)fd_in + b; 1113 #else 1114 addr = (char *)fd_in; 1115 if (abi_nfdbits == NFDBITS) { 1116 addr += rounddown(b, sizeof(fd_mask)) + 1117 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 1118 } else { 1119 addr += rounddown(b, sizeof(uint32_t)) + 1120 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 1121 } 1122 #endif 1123 if (addr != oaddr) { 1124 res = fubyte(addr); 1125 if (res == -1) 1126 return (EFAULT); 1127 oaddr = addr; 1128 bits = res; 1129 } 1130 if ((bits & (1 << (i % NBBY))) != 0) 1131 return (EBADF); 1132 } 1133 return (0); 1134 } 1135 1136 int 1137 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 1138 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 1139 { 1140 struct filedesc *fdp; 1141 /* 1142 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 1143 * infds with the new FD_SETSIZE of 1024, and more than enough for 1144 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 1145 * of 256. 1146 */ 1147 fd_mask s_selbits[howmany(2048, NFDBITS)]; 1148 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 1149 struct timeval rtv; 1150 sbintime_t asbt, precision, rsbt; 1151 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 1152 int error, lf, ndu; 1153 1154 if (nd < 0) 1155 return (EINVAL); 1156 fdp = td->td_proc->p_fd; 1157 ndu = nd; 1158 lf = fdp->fd_nfiles; 1159 if (nd > lf) 1160 nd = lf; 1161 1162 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 1163 if (error != 0) 1164 return (error); 1165 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 1166 if (error != 0) 1167 return (error); 1168 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 1169 if (error != 0) 1170 return (error); 1171 1172 /* 1173 * Allocate just enough bits for the non-null fd_sets. Use the 1174 * preallocated auto buffer if possible. 1175 */ 1176 nfdbits = roundup(nd, NFDBITS); 1177 ncpbytes = nfdbits / NBBY; 1178 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 1179 nbufbytes = 0; 1180 if (fd_in != NULL) 1181 nbufbytes += 2 * ncpbytes; 1182 if (fd_ou != NULL) 1183 nbufbytes += 2 * ncpbytes; 1184 if (fd_ex != NULL) 1185 nbufbytes += 2 * ncpbytes; 1186 if (nbufbytes <= sizeof s_selbits) 1187 selbits = &s_selbits[0]; 1188 else 1189 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1190 1191 /* 1192 * Assign pointers into the bit buffers and fetch the input bits. 1193 * Put the output buffers together so that they can be bzeroed 1194 * together. 1195 */ 1196 sbp = selbits; 1197 #define getbits(name, x) \ 1198 do { \ 1199 if (name == NULL) { \ 1200 ibits[x] = NULL; \ 1201 obits[x] = NULL; \ 1202 } else { \ 1203 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1204 obits[x] = sbp; \ 1205 sbp += ncpbytes / sizeof *sbp; \ 1206 error = copyin(name, ibits[x], ncpubytes); \ 1207 if (error != 0) \ 1208 goto done; \ 1209 if (ncpbytes != ncpubytes) \ 1210 bzero((char *)ibits[x] + ncpubytes, \ 1211 ncpbytes - ncpubytes); \ 1212 } \ 1213 } while (0) 1214 getbits(fd_in, 0); 1215 getbits(fd_ou, 1); 1216 getbits(fd_ex, 2); 1217 #undef getbits 1218 1219 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1220 /* 1221 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1222 * we are running under 32-bit emulation. This should be more 1223 * generic. 1224 */ 1225 #define swizzle_fdset(bits) \ 1226 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1227 int i; \ 1228 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1229 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1230 } 1231 #else 1232 #define swizzle_fdset(bits) 1233 #endif 1234 1235 /* Make sure the bit order makes it through an ABI transition */ 1236 swizzle_fdset(ibits[0]); 1237 swizzle_fdset(ibits[1]); 1238 swizzle_fdset(ibits[2]); 1239 1240 if (nbufbytes != 0) 1241 bzero(selbits, nbufbytes / 2); 1242 1243 precision = 0; 1244 if (tvp != NULL) { 1245 rtv = *tvp; 1246 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1247 rtv.tv_usec >= 1000000) { 1248 error = EINVAL; 1249 goto done; 1250 } 1251 if (!timevalisset(&rtv)) 1252 asbt = 0; 1253 else if (rtv.tv_sec <= INT32_MAX) { 1254 rsbt = tvtosbt(rtv); 1255 precision = rsbt; 1256 precision >>= tc_precexp; 1257 if (TIMESEL(&asbt, rsbt)) 1258 asbt += tc_tick_sbt; 1259 if (asbt <= SBT_MAX - rsbt) 1260 asbt += rsbt; 1261 else 1262 asbt = -1; 1263 } else 1264 asbt = -1; 1265 } else 1266 asbt = -1; 1267 seltdinit(td); 1268 /* Iterate until the timeout expires or descriptors become ready. */ 1269 for (;;) { 1270 error = selscan(td, ibits, obits, nd); 1271 if (error || td->td_retval[0] != 0) 1272 break; 1273 error = seltdwait(td, asbt, precision); 1274 if (error) 1275 break; 1276 error = selrescan(td, ibits, obits); 1277 if (error || td->td_retval[0] != 0) 1278 break; 1279 } 1280 seltdclear(td); 1281 1282 done: 1283 /* select is not restarted after signals... */ 1284 if (error == ERESTART) 1285 error = EINTR; 1286 if (error == EWOULDBLOCK) 1287 error = 0; 1288 1289 /* swizzle bit order back, if necessary */ 1290 swizzle_fdset(obits[0]); 1291 swizzle_fdset(obits[1]); 1292 swizzle_fdset(obits[2]); 1293 #undef swizzle_fdset 1294 1295 #define putbits(name, x) \ 1296 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1297 error = error2; 1298 if (error == 0) { 1299 int error2; 1300 1301 putbits(fd_in, 0); 1302 putbits(fd_ou, 1); 1303 putbits(fd_ex, 2); 1304 #undef putbits 1305 } 1306 if (selbits != &s_selbits[0]) 1307 free(selbits, M_SELECT); 1308 1309 return (error); 1310 } 1311 /* 1312 * Convert a select bit set to poll flags. 1313 * 1314 * The backend always returns POLLHUP/POLLERR if appropriate and we 1315 * return this as a set bit in any set. 1316 */ 1317 static const int select_flags[3] = { 1318 POLLRDNORM | POLLHUP | POLLERR, 1319 POLLWRNORM | POLLHUP | POLLERR, 1320 POLLRDBAND | POLLERR 1321 }; 1322 1323 /* 1324 * Compute the fo_poll flags required for a fd given by the index and 1325 * bit position in the fd_mask array. 1326 */ 1327 static __inline int 1328 selflags(fd_mask **ibits, int idx, fd_mask bit) 1329 { 1330 int flags; 1331 int msk; 1332 1333 flags = 0; 1334 for (msk = 0; msk < 3; msk++) { 1335 if (ibits[msk] == NULL) 1336 continue; 1337 if ((ibits[msk][idx] & bit) == 0) 1338 continue; 1339 flags |= select_flags[msk]; 1340 } 1341 return (flags); 1342 } 1343 1344 /* 1345 * Set the appropriate output bits given a mask of fired events and the 1346 * input bits originally requested. 1347 */ 1348 static __inline int 1349 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1350 { 1351 int msk; 1352 int n; 1353 1354 n = 0; 1355 for (msk = 0; msk < 3; msk++) { 1356 if ((events & select_flags[msk]) == 0) 1357 continue; 1358 if (ibits[msk] == NULL) 1359 continue; 1360 if ((ibits[msk][idx] & bit) == 0) 1361 continue; 1362 /* 1363 * XXX Check for a duplicate set. This can occur because a 1364 * socket calls selrecord() twice for each poll() call 1365 * resulting in two selfds per real fd. selrescan() will 1366 * call selsetbits twice as a result. 1367 */ 1368 if ((obits[msk][idx] & bit) != 0) 1369 continue; 1370 obits[msk][idx] |= bit; 1371 n++; 1372 } 1373 1374 return (n); 1375 } 1376 1377 /* 1378 * Traverse the list of fds attached to this thread's seltd and check for 1379 * completion. 1380 */ 1381 static int 1382 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1383 { 1384 struct filedesc *fdp; 1385 struct selinfo *si; 1386 struct seltd *stp; 1387 struct selfd *sfp; 1388 struct selfd *sfn; 1389 struct file *fp; 1390 fd_mask bit; 1391 int fd, ev, n, idx; 1392 int error; 1393 bool only_user; 1394 1395 fdp = td->td_proc->p_fd; 1396 stp = td->td_sel; 1397 n = 0; 1398 only_user = FILEDESC_IS_ONLY_USER(fdp); 1399 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1400 fd = (int)(uintptr_t)sfp->sf_cookie; 1401 si = sfp->sf_si; 1402 selfdfree(stp, sfp); 1403 /* If the selinfo wasn't cleared the event didn't fire. */ 1404 if (si != NULL) 1405 continue; 1406 if (only_user) 1407 error = fget_only_user(fdp, fd, &cap_event_rights, &fp); 1408 else 1409 error = fget_unlocked(td, fd, &cap_event_rights, &fp); 1410 if (__predict_false(error != 0)) 1411 return (error); 1412 idx = fd / NFDBITS; 1413 bit = (fd_mask)1 << (fd % NFDBITS); 1414 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1415 if (only_user) 1416 fput_only_user(fdp, fp); 1417 else 1418 fdrop(fp, td); 1419 if (ev != 0) 1420 n += selsetbits(ibits, obits, idx, bit, ev); 1421 } 1422 stp->st_flags = 0; 1423 td->td_retval[0] = n; 1424 return (0); 1425 } 1426 1427 /* 1428 * Perform the initial filedescriptor scan and register ourselves with 1429 * each selinfo. 1430 */ 1431 static int 1432 selscan(struct thread *td, fd_mask **ibits, fd_mask **obits, int nfd) 1433 { 1434 struct filedesc *fdp; 1435 struct file *fp; 1436 fd_mask bit; 1437 int ev, flags, end, fd; 1438 int n, idx; 1439 int error; 1440 bool only_user; 1441 1442 fdp = td->td_proc->p_fd; 1443 n = 0; 1444 only_user = FILEDESC_IS_ONLY_USER(fdp); 1445 for (idx = 0, fd = 0; fd < nfd; idx++) { 1446 end = imin(fd + NFDBITS, nfd); 1447 for (bit = 1; fd < end; bit <<= 1, fd++) { 1448 /* Compute the list of events we're interested in. */ 1449 flags = selflags(ibits, idx, bit); 1450 if (flags == 0) 1451 continue; 1452 if (only_user) 1453 error = fget_only_user(fdp, fd, &cap_event_rights, &fp); 1454 else 1455 error = fget_unlocked(td, fd, &cap_event_rights, &fp); 1456 if (__predict_false(error != 0)) 1457 return (error); 1458 selfdalloc(td, (void *)(uintptr_t)fd); 1459 ev = fo_poll(fp, flags, td->td_ucred, td); 1460 if (only_user) 1461 fput_only_user(fdp, fp); 1462 else 1463 fdrop(fp, td); 1464 if (ev != 0) 1465 n += selsetbits(ibits, obits, idx, bit, ev); 1466 } 1467 } 1468 1469 td->td_retval[0] = n; 1470 return (0); 1471 } 1472 1473 int 1474 sys_poll(struct thread *td, struct poll_args *uap) 1475 { 1476 struct timespec ts, *tsp; 1477 1478 if (uap->timeout != INFTIM) { 1479 if (uap->timeout < 0) 1480 return (EINVAL); 1481 ts.tv_sec = uap->timeout / 1000; 1482 ts.tv_nsec = (uap->timeout % 1000) * 1000000; 1483 tsp = &ts; 1484 } else 1485 tsp = NULL; 1486 1487 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); 1488 } 1489 1490 /* 1491 * kfds points to an array in the kernel. 1492 */ 1493 int 1494 kern_poll_kfds(struct thread *td, struct pollfd *kfds, u_int nfds, 1495 struct timespec *tsp, sigset_t *uset) 1496 { 1497 sbintime_t sbt, precision, tmp; 1498 time_t over; 1499 struct timespec ts; 1500 int error; 1501 1502 precision = 0; 1503 if (tsp != NULL) { 1504 if (!timespecvalid_interval(tsp)) 1505 return (EINVAL); 1506 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1507 sbt = 0; 1508 else { 1509 ts = *tsp; 1510 if (ts.tv_sec > INT32_MAX / 2) { 1511 over = ts.tv_sec - INT32_MAX / 2; 1512 ts.tv_sec -= over; 1513 } else 1514 over = 0; 1515 tmp = tstosbt(ts); 1516 precision = tmp; 1517 precision >>= tc_precexp; 1518 if (TIMESEL(&sbt, tmp)) 1519 sbt += tc_tick_sbt; 1520 sbt += tmp; 1521 } 1522 } else 1523 sbt = -1; 1524 1525 if (uset != NULL) { 1526 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1527 &td->td_oldsigmask, 0); 1528 if (error) 1529 return (error); 1530 td->td_pflags |= TDP_OLDMASK; 1531 /* 1532 * Make sure that ast() is called on return to 1533 * usermode and TDP_OLDMASK is cleared, restoring old 1534 * sigmask. 1535 */ 1536 ast_sched(td, TDA_SIGSUSPEND); 1537 } 1538 1539 seltdinit(td); 1540 /* Iterate until the timeout expires or descriptors become ready. */ 1541 for (;;) { 1542 error = pollscan(td, kfds, nfds); 1543 if (error || td->td_retval[0] != 0) 1544 break; 1545 error = seltdwait(td, sbt, precision); 1546 if (error) 1547 break; 1548 error = pollrescan(td); 1549 if (error || td->td_retval[0] != 0) 1550 break; 1551 } 1552 seltdclear(td); 1553 1554 /* poll is not restarted after signals... */ 1555 if (error == ERESTART) 1556 error = EINTR; 1557 if (error == EWOULDBLOCK) 1558 error = 0; 1559 return (error); 1560 } 1561 1562 int 1563 sys_ppoll(struct thread *td, struct ppoll_args *uap) 1564 { 1565 struct timespec ts, *tsp; 1566 sigset_t set, *ssp; 1567 int error; 1568 1569 if (uap->ts != NULL) { 1570 error = copyin(uap->ts, &ts, sizeof(ts)); 1571 if (error) 1572 return (error); 1573 tsp = &ts; 1574 } else 1575 tsp = NULL; 1576 if (uap->set != NULL) { 1577 error = copyin(uap->set, &set, sizeof(set)); 1578 if (error) 1579 return (error); 1580 ssp = &set; 1581 } else 1582 ssp = NULL; 1583 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); 1584 } 1585 1586 /* 1587 * ufds points to an array in user space. 1588 */ 1589 int 1590 kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds, 1591 struct timespec *tsp, sigset_t *set) 1592 { 1593 struct pollfd *kfds; 1594 struct pollfd stackfds[32]; 1595 int error; 1596 1597 if (kern_poll_maxfds(nfds)) 1598 return (EINVAL); 1599 if (nfds > nitems(stackfds)) 1600 kfds = mallocarray(nfds, sizeof(*kfds), M_TEMP, M_WAITOK); 1601 else 1602 kfds = stackfds; 1603 error = copyin(ufds, kfds, nfds * sizeof(*kfds)); 1604 if (error != 0) 1605 goto out; 1606 1607 error = kern_poll_kfds(td, kfds, nfds, tsp, set); 1608 if (error == 0) 1609 error = pollout(td, kfds, ufds, nfds); 1610 #ifdef KTRACE 1611 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1612 ktrstructarray("pollfd", UIO_USERSPACE, ufds, nfds, 1613 sizeof(*ufds)); 1614 #endif 1615 1616 out: 1617 if (nfds > nitems(stackfds)) 1618 free(kfds, M_TEMP); 1619 return (error); 1620 } 1621 1622 bool 1623 kern_poll_maxfds(u_int nfds) 1624 { 1625 1626 /* 1627 * This is kinda bogus. We have fd limits, but that is not 1628 * really related to the size of the pollfd array. Make sure 1629 * we let the process use at least FD_SETSIZE entries and at 1630 * least enough for the system-wide limits. We want to be reasonably 1631 * safe, but not overly restrictive. 1632 */ 1633 return (nfds > maxfilesperproc && nfds > FD_SETSIZE); 1634 } 1635 1636 static int 1637 pollrescan(struct thread *td) 1638 { 1639 struct seltd *stp; 1640 struct selfd *sfp; 1641 struct selfd *sfn; 1642 struct selinfo *si; 1643 struct filedesc *fdp; 1644 struct file *fp; 1645 struct pollfd *fd; 1646 int n, error; 1647 bool only_user; 1648 1649 n = 0; 1650 fdp = td->td_proc->p_fd; 1651 stp = td->td_sel; 1652 only_user = FILEDESC_IS_ONLY_USER(fdp); 1653 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1654 fd = (struct pollfd *)sfp->sf_cookie; 1655 si = sfp->sf_si; 1656 selfdfree(stp, sfp); 1657 /* If the selinfo wasn't cleared the event didn't fire. */ 1658 if (si != NULL) 1659 continue; 1660 if (only_user) 1661 error = fget_only_user(fdp, fd->fd, &cap_event_rights, &fp); 1662 else 1663 error = fget_unlocked(td, fd->fd, &cap_event_rights, &fp); 1664 if (__predict_false(error != 0)) { 1665 fd->revents = POLLNVAL; 1666 n++; 1667 continue; 1668 } 1669 /* 1670 * Note: backend also returns POLLHUP and 1671 * POLLERR if appropriate. 1672 */ 1673 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1674 if (only_user) 1675 fput_only_user(fdp, fp); 1676 else 1677 fdrop(fp, td); 1678 if (fd->revents != 0) 1679 n++; 1680 } 1681 stp->st_flags = 0; 1682 td->td_retval[0] = n; 1683 return (0); 1684 } 1685 1686 static int 1687 pollout(struct thread *td, struct pollfd *fds, struct pollfd *ufds, u_int nfd) 1688 { 1689 int error = 0; 1690 u_int i = 0; 1691 u_int n = 0; 1692 1693 for (i = 0; i < nfd; i++) { 1694 error = copyout(&fds->revents, &ufds->revents, 1695 sizeof(ufds->revents)); 1696 if (error) 1697 return (error); 1698 if (fds->revents != 0) 1699 n++; 1700 fds++; 1701 ufds++; 1702 } 1703 td->td_retval[0] = n; 1704 return (0); 1705 } 1706 1707 static int 1708 pollscan(struct thread *td, struct pollfd *fds, u_int nfd) 1709 { 1710 struct filedesc *fdp; 1711 struct file *fp; 1712 int i, n, error; 1713 bool only_user; 1714 1715 n = 0; 1716 fdp = td->td_proc->p_fd; 1717 only_user = FILEDESC_IS_ONLY_USER(fdp); 1718 for (i = 0; i < nfd; i++, fds++) { 1719 if (fds->fd < 0) { 1720 fds->revents = 0; 1721 continue; 1722 } 1723 if (only_user) 1724 error = fget_only_user(fdp, fds->fd, &cap_event_rights, &fp); 1725 else 1726 error = fget_unlocked(td, fds->fd, &cap_event_rights, &fp); 1727 if (__predict_false(error != 0)) { 1728 fds->revents = POLLNVAL; 1729 n++; 1730 continue; 1731 } 1732 /* 1733 * Note: backend also returns POLLHUP and 1734 * POLLERR if appropriate. 1735 */ 1736 selfdalloc(td, fds); 1737 fds->revents = fo_poll(fp, fds->events, 1738 td->td_ucred, td); 1739 if (only_user) 1740 fput_only_user(fdp, fp); 1741 else 1742 fdrop(fp, td); 1743 /* 1744 * POSIX requires POLLOUT to be never 1745 * set simultaneously with POLLHUP. 1746 */ 1747 if ((fds->revents & POLLHUP) != 0) 1748 fds->revents &= ~POLLOUT; 1749 1750 if (fds->revents != 0) 1751 n++; 1752 } 1753 td->td_retval[0] = n; 1754 return (0); 1755 } 1756 1757 /* 1758 * XXX This was created specifically to support netncp and netsmb. This 1759 * allows the caller to specify a socket to wait for events on. It returns 1760 * 0 if any events matched and an error otherwise. There is no way to 1761 * determine which events fired. 1762 */ 1763 int 1764 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1765 { 1766 struct timeval rtv; 1767 sbintime_t asbt, precision, rsbt; 1768 int error; 1769 1770 precision = 0; /* stupid gcc! */ 1771 if (tvp != NULL) { 1772 rtv = *tvp; 1773 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1774 rtv.tv_usec >= 1000000) 1775 return (EINVAL); 1776 if (!timevalisset(&rtv)) 1777 asbt = 0; 1778 else if (rtv.tv_sec <= INT32_MAX) { 1779 rsbt = tvtosbt(rtv); 1780 precision = rsbt; 1781 precision >>= tc_precexp; 1782 if (TIMESEL(&asbt, rsbt)) 1783 asbt += tc_tick_sbt; 1784 if (asbt <= SBT_MAX - rsbt) 1785 asbt += rsbt; 1786 else 1787 asbt = -1; 1788 } else 1789 asbt = -1; 1790 } else 1791 asbt = -1; 1792 seltdinit(td); 1793 /* 1794 * Iterate until the timeout expires or the socket becomes ready. 1795 */ 1796 for (;;) { 1797 selfdalloc(td, NULL); 1798 if (sopoll(so, events, NULL, td) != 0) { 1799 error = 0; 1800 break; 1801 } 1802 error = seltdwait(td, asbt, precision); 1803 if (error) 1804 break; 1805 } 1806 seltdclear(td); 1807 /* XXX Duplicates ncp/smb behavior. */ 1808 if (error == ERESTART) 1809 error = 0; 1810 return (error); 1811 } 1812 1813 /* 1814 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1815 * have two select sets, one for read and another for write. 1816 */ 1817 static void 1818 selfdalloc(struct thread *td, void *cookie) 1819 { 1820 struct seltd *stp; 1821 1822 stp = td->td_sel; 1823 if (stp->st_free1 == NULL) 1824 stp->st_free1 = malloc(sizeof(*stp->st_free1), M_SELFD, M_WAITOK|M_ZERO); 1825 stp->st_free1->sf_td = stp; 1826 stp->st_free1->sf_cookie = cookie; 1827 if (stp->st_free2 == NULL) 1828 stp->st_free2 = malloc(sizeof(*stp->st_free2), M_SELFD, M_WAITOK|M_ZERO); 1829 stp->st_free2->sf_td = stp; 1830 stp->st_free2->sf_cookie = cookie; 1831 } 1832 1833 static void 1834 selfdfree(struct seltd *stp, struct selfd *sfp) 1835 { 1836 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1837 /* 1838 * Paired with doselwakeup. 1839 */ 1840 if (atomic_load_acq_ptr((uintptr_t *)&sfp->sf_si) != (uintptr_t)NULL) { 1841 mtx_lock(sfp->sf_mtx); 1842 if (sfp->sf_si != NULL) { 1843 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1844 } 1845 mtx_unlock(sfp->sf_mtx); 1846 } 1847 free(sfp, M_SELFD); 1848 } 1849 1850 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1851 void 1852 seldrain(struct selinfo *sip) 1853 { 1854 1855 /* 1856 * This feature is already provided by doselwakeup(), thus it is 1857 * enough to go for it. 1858 * Eventually, the context, should take care to avoid races 1859 * between thread calling select()/poll() and file descriptor 1860 * detaching, but, again, the races are just the same as 1861 * selwakeup(). 1862 */ 1863 doselwakeup(sip, -1); 1864 } 1865 1866 /* 1867 * Record a select request. 1868 */ 1869 void 1870 selrecord(struct thread *selector, struct selinfo *sip) 1871 { 1872 struct selfd *sfp; 1873 struct seltd *stp; 1874 struct mtx *mtxp; 1875 1876 stp = selector->td_sel; 1877 /* 1878 * Don't record when doing a rescan. 1879 */ 1880 if (stp->st_flags & SELTD_RESCAN) 1881 return; 1882 /* 1883 * Grab one of the preallocated descriptors. 1884 */ 1885 sfp = NULL; 1886 if ((sfp = stp->st_free1) != NULL) 1887 stp->st_free1 = NULL; 1888 else if ((sfp = stp->st_free2) != NULL) 1889 stp->st_free2 = NULL; 1890 else 1891 panic("selrecord: No free selfd on selq"); 1892 mtxp = sip->si_mtx; 1893 if (mtxp == NULL) 1894 mtxp = mtx_pool_find(mtxpool_select, sip); 1895 /* 1896 * Initialize the sfp and queue it in the thread. 1897 */ 1898 sfp->sf_si = sip; 1899 sfp->sf_mtx = mtxp; 1900 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1901 /* 1902 * Now that we've locked the sip, check for initialization. 1903 */ 1904 mtx_lock(mtxp); 1905 if (sip->si_mtx == NULL) { 1906 sip->si_mtx = mtxp; 1907 TAILQ_INIT(&sip->si_tdlist); 1908 } 1909 /* 1910 * Add this thread to the list of selfds listening on this selinfo. 1911 */ 1912 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1913 mtx_unlock(sip->si_mtx); 1914 } 1915 1916 /* Wake up a selecting thread. */ 1917 void 1918 selwakeup(struct selinfo *sip) 1919 { 1920 doselwakeup(sip, -1); 1921 } 1922 1923 /* Wake up a selecting thread, and set its priority. */ 1924 void 1925 selwakeuppri(struct selinfo *sip, int pri) 1926 { 1927 doselwakeup(sip, pri); 1928 } 1929 1930 /* 1931 * Do a wakeup when a selectable event occurs. 1932 */ 1933 static void 1934 doselwakeup(struct selinfo *sip, int pri) 1935 { 1936 struct selfd *sfp; 1937 struct selfd *sfn; 1938 struct seltd *stp; 1939 1940 /* If it's not initialized there can't be any waiters. */ 1941 if (sip->si_mtx == NULL) 1942 return; 1943 /* 1944 * Locking the selinfo locks all selfds associated with it. 1945 */ 1946 mtx_lock(sip->si_mtx); 1947 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1948 /* 1949 * Once we remove this sfp from the list and clear the 1950 * sf_si seltdclear will know to ignore this si. 1951 */ 1952 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1953 stp = sfp->sf_td; 1954 mtx_lock(&stp->st_mtx); 1955 stp->st_flags |= SELTD_PENDING; 1956 cv_broadcastpri(&stp->st_wait, pri); 1957 mtx_unlock(&stp->st_mtx); 1958 /* 1959 * Paired with selfdfree. 1960 * 1961 * Storing this only after the wakeup provides an invariant that 1962 * stp is not used after selfdfree returns. 1963 */ 1964 atomic_store_rel_ptr((uintptr_t *)&sfp->sf_si, (uintptr_t)NULL); 1965 } 1966 mtx_unlock(sip->si_mtx); 1967 } 1968 1969 static void 1970 seltdinit(struct thread *td) 1971 { 1972 struct seltd *stp; 1973 1974 stp = td->td_sel; 1975 if (stp != NULL) { 1976 MPASS(stp->st_flags == 0); 1977 MPASS(STAILQ_EMPTY(&stp->st_selq)); 1978 return; 1979 } 1980 stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1981 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1982 cv_init(&stp->st_wait, "select"); 1983 stp->st_flags = 0; 1984 STAILQ_INIT(&stp->st_selq); 1985 td->td_sel = stp; 1986 } 1987 1988 static int 1989 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1990 { 1991 struct seltd *stp; 1992 int error; 1993 1994 stp = td->td_sel; 1995 /* 1996 * An event of interest may occur while we do not hold the seltd 1997 * locked so check the pending flag before we sleep. 1998 */ 1999 mtx_lock(&stp->st_mtx); 2000 /* 2001 * Any further calls to selrecord will be a rescan. 2002 */ 2003 stp->st_flags |= SELTD_RESCAN; 2004 if (stp->st_flags & SELTD_PENDING) { 2005 mtx_unlock(&stp->st_mtx); 2006 return (0); 2007 } 2008 if (sbt == 0) 2009 error = EWOULDBLOCK; 2010 else if (sbt != -1) 2011 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 2012 sbt, precision, C_ABSOLUTE); 2013 else 2014 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 2015 mtx_unlock(&stp->st_mtx); 2016 2017 return (error); 2018 } 2019 2020 void 2021 seltdfini(struct thread *td) 2022 { 2023 struct seltd *stp; 2024 2025 stp = td->td_sel; 2026 if (stp == NULL) 2027 return; 2028 MPASS(stp->st_flags == 0); 2029 MPASS(STAILQ_EMPTY(&stp->st_selq)); 2030 if (stp->st_free1) 2031 free(stp->st_free1, M_SELFD); 2032 if (stp->st_free2) 2033 free(stp->st_free2, M_SELFD); 2034 td->td_sel = NULL; 2035 cv_destroy(&stp->st_wait); 2036 mtx_destroy(&stp->st_mtx); 2037 free(stp, M_SELECT); 2038 } 2039 2040 /* 2041 * Remove the references to the thread from all of the objects we were 2042 * polling. 2043 */ 2044 static void 2045 seltdclear(struct thread *td) 2046 { 2047 struct seltd *stp; 2048 struct selfd *sfp; 2049 struct selfd *sfn; 2050 2051 stp = td->td_sel; 2052 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 2053 selfdfree(stp, sfp); 2054 stp->st_flags = 0; 2055 } 2056 2057 static void selectinit(void *); 2058 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 2059 static void 2060 selectinit(void *dummy __unused) 2061 { 2062 2063 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 2064 } 2065 2066 /* 2067 * Set up a syscall return value that follows the convention specified for 2068 * posix_* functions. 2069 */ 2070 int 2071 kern_posix_error(struct thread *td, int error) 2072 { 2073 2074 if (error <= 0) 2075 return (error); 2076 td->td_errno = error; 2077 td->td_pflags |= TDP_NERRNO; 2078 td->td_retval[0] = error; 2079 return (0); 2080 } 2081 2082 int 2083 kcmp_cmp(uintptr_t a, uintptr_t b) 2084 { 2085 if (a == b) 2086 return (0); 2087 else if (a < b) 2088 return (1); 2089 return (2); 2090 } 2091 2092 static int 2093 kcmp_pget(struct thread *td, pid_t pid, struct proc **pp) 2094 { 2095 if (pid == td->td_proc->p_pid) { 2096 *pp = td->td_proc; 2097 return (0); 2098 } 2099 return (pget(pid, PGET_CANDEBUG | PGET_NOTWEXIT | PGET_HOLD, pp)); 2100 } 2101 2102 int 2103 kern_kcmp(struct thread *td, pid_t pid1, pid_t pid2, int type, 2104 uintptr_t idx1, uintptr_t idx2) 2105 { 2106 struct proc *p1, *p2; 2107 struct file *fp1, *fp2; 2108 int error, res; 2109 2110 res = -1; 2111 p1 = p2 = NULL; 2112 error = kcmp_pget(td, pid1, &p1); 2113 if (error == 0) 2114 error = kcmp_pget(td, pid2, &p2); 2115 if (error != 0) 2116 goto out; 2117 2118 switch (type) { 2119 case KCMP_FILE: 2120 case KCMP_FILEOBJ: 2121 error = fget_remote(td, p1, idx1, &fp1); 2122 if (error == 0) { 2123 error = fget_remote(td, p2, idx2, &fp2); 2124 if (error == 0) { 2125 if (type == KCMP_FILEOBJ) 2126 res = fo_cmp(fp1, fp2, td); 2127 else 2128 res = kcmp_cmp((uintptr_t)fp1, 2129 (uintptr_t)fp2); 2130 fdrop(fp2, td); 2131 } 2132 fdrop(fp1, td); 2133 } 2134 break; 2135 case KCMP_FILES: 2136 res = kcmp_cmp((uintptr_t)p1->p_fd, (uintptr_t)p2->p_fd); 2137 break; 2138 case KCMP_SIGHAND: 2139 res = kcmp_cmp((uintptr_t)p1->p_sigacts, 2140 (uintptr_t)p2->p_sigacts); 2141 break; 2142 case KCMP_VM: 2143 res = kcmp_cmp((uintptr_t)p1->p_vmspace, 2144 (uintptr_t)p2->p_vmspace); 2145 break; 2146 default: 2147 error = EINVAL; 2148 break; 2149 } 2150 2151 out: 2152 if (p1 != NULL && p1 != td->td_proc) 2153 PRELE(p1); 2154 if (p2 != NULL && p2 != td->td_proc) 2155 PRELE(p2); 2156 2157 td->td_retval[0] = res; 2158 return (error); 2159 } 2160 2161 int 2162 sys_kcmp(struct thread *td, struct kcmp_args *uap) 2163 { 2164 return (kern_kcmp(td, uap->pid1, uap->pid2, uap->type, 2165 uap->idx1, uap->idx2)); 2166 } 2167 2168 int 2169 file_kcmp_generic(struct file *fp1, struct file *fp2, struct thread *td) 2170 { 2171 if (fp1->f_type != fp2->f_type) 2172 return (3); 2173 return (kcmp_cmp((uintptr_t)fp1->f_data, (uintptr_t)fp2->f_data)); 2174 } 2175