Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/sys_generic.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_capsicum.h" 41 #include "opt_compat.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/capsicum.h> 48 #include <sys/filedesc.h> 49 #include <sys/filio.h> 50 #include <sys/fcntl.h> 51 #include <sys/file.h> 52 #include <sys/lock.h> 53 #include <sys/proc.h> 54 #include <sys/signalvar.h> 55 #include <sys/socketvar.h> 56 #include <sys/uio.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/limits.h> 60 #include <sys/malloc.h> 61 #include <sys/poll.h> 62 #include <sys/resourcevar.h> 63 #include <sys/selinfo.h> 64 #include <sys/sleepqueue.h> 65 #include <sys/syscallsubr.h> 66 #include <sys/sysctl.h> 67 #include <sys/sysent.h> 68 #include <sys/vnode.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 u_int sf_refs; 159 }; 160 161 static uma_zone_t selfd_zone; 162 static struct mtx_pool *mtxpool_select; 163 164 #ifdef __LP64__ 165 size_t 166 devfs_iosize_max(void) 167 { 168 169 return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 170 INT_MAX : SSIZE_MAX); 171 } 172 173 size_t 174 iosize_max(void) 175 { 176 177 return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? 178 INT_MAX : SSIZE_MAX); 179 } 180 #endif 181 182 #ifndef _SYS_SYSPROTO_H_ 183 struct read_args { 184 int fd; 185 void *buf; 186 size_t nbyte; 187 }; 188 #endif 189 int 190 sys_read(td, uap) 191 struct thread *td; 192 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 cap_rights_t rights; 286 int error; 287 288 error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp); 289 if (error) 290 return (error); 291 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 292 fdrop(fp, td); 293 return (error); 294 } 295 296 /* 297 * Scatter positioned read system call. 298 */ 299 #ifndef _SYS_SYSPROTO_H_ 300 struct preadv_args { 301 int fd; 302 struct iovec *iovp; 303 u_int iovcnt; 304 off_t offset; 305 }; 306 #endif 307 int 308 sys_preadv(struct thread *td, struct preadv_args *uap) 309 { 310 struct uio *auio; 311 int error; 312 313 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 314 if (error) 315 return (error); 316 error = kern_preadv(td, uap->fd, auio, uap->offset); 317 free(auio, M_IOV); 318 return (error); 319 } 320 321 int 322 kern_preadv(td, fd, auio, offset) 323 struct thread *td; 324 int fd; 325 struct uio *auio; 326 off_t offset; 327 { 328 struct file *fp; 329 cap_rights_t rights; 330 int error; 331 332 error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp); 333 if (error) 334 return (error); 335 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 336 error = ESPIPE; 337 else if (offset < 0 && 338 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 339 error = EINVAL; 340 else 341 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 342 fdrop(fp, td); 343 return (error); 344 } 345 346 /* 347 * Common code for readv and preadv that reads data in 348 * from a file using the passed in uio, offset, and flags. 349 */ 350 static int 351 dofileread(td, fd, fp, auio, offset, flags) 352 struct thread *td; 353 int fd; 354 struct file *fp; 355 struct uio *auio; 356 off_t offset; 357 int flags; 358 { 359 ssize_t cnt; 360 int error; 361 #ifdef KTRACE 362 struct uio *ktruio = NULL; 363 #endif 364 365 AUDIT_ARG_FD(fd); 366 367 /* Finish zero length reads right here */ 368 if (auio->uio_resid == 0) { 369 td->td_retval[0] = 0; 370 return(0); 371 } 372 auio->uio_rw = UIO_READ; 373 auio->uio_offset = offset; 374 auio->uio_td = td; 375 #ifdef KTRACE 376 if (KTRPOINT(td, KTR_GENIO)) 377 ktruio = cloneuio(auio); 378 #endif 379 cnt = auio->uio_resid; 380 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 381 if (auio->uio_resid != cnt && (error == ERESTART || 382 error == EINTR || error == EWOULDBLOCK)) 383 error = 0; 384 } 385 cnt -= auio->uio_resid; 386 #ifdef KTRACE 387 if (ktruio != NULL) { 388 ktruio->uio_resid = cnt; 389 ktrgenio(fd, UIO_READ, ktruio, error); 390 } 391 #endif 392 td->td_retval[0] = cnt; 393 return (error); 394 } 395 396 #ifndef _SYS_SYSPROTO_H_ 397 struct write_args { 398 int fd; 399 const void *buf; 400 size_t nbyte; 401 }; 402 #endif 403 int 404 sys_write(td, uap) 405 struct thread *td; 406 struct write_args *uap; 407 { 408 struct uio auio; 409 struct iovec aiov; 410 int error; 411 412 if (uap->nbyte > IOSIZE_MAX) 413 return (EINVAL); 414 aiov.iov_base = (void *)(uintptr_t)uap->buf; 415 aiov.iov_len = uap->nbyte; 416 auio.uio_iov = &aiov; 417 auio.uio_iovcnt = 1; 418 auio.uio_resid = uap->nbyte; 419 auio.uio_segflg = UIO_USERSPACE; 420 error = kern_writev(td, uap->fd, &auio); 421 return(error); 422 } 423 424 /* 425 * Positioned write system call. 426 */ 427 #ifndef _SYS_SYSPROTO_H_ 428 struct pwrite_args { 429 int fd; 430 const void *buf; 431 size_t nbyte; 432 int pad; 433 off_t offset; 434 }; 435 #endif 436 int 437 sys_pwrite(struct thread *td, struct pwrite_args *uap) 438 { 439 440 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 441 } 442 443 int 444 kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte, 445 off_t offset) 446 { 447 struct uio auio; 448 struct iovec aiov; 449 int error; 450 451 if (nbyte > IOSIZE_MAX) 452 return (EINVAL); 453 aiov.iov_base = (void *)(uintptr_t)buf; 454 aiov.iov_len = nbyte; 455 auio.uio_iov = &aiov; 456 auio.uio_iovcnt = 1; 457 auio.uio_resid = nbyte; 458 auio.uio_segflg = UIO_USERSPACE; 459 error = kern_pwritev(td, fd, &auio, offset); 460 return(error); 461 } 462 463 #if defined(COMPAT_FREEBSD6) 464 int 465 freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap) 466 { 467 468 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); 469 } 470 #endif 471 472 /* 473 * Gather write system call. 474 */ 475 #ifndef _SYS_SYSPROTO_H_ 476 struct writev_args { 477 int fd; 478 struct iovec *iovp; 479 u_int iovcnt; 480 }; 481 #endif 482 int 483 sys_writev(struct thread *td, struct writev_args *uap) 484 { 485 struct uio *auio; 486 int error; 487 488 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 489 if (error) 490 return (error); 491 error = kern_writev(td, uap->fd, auio); 492 free(auio, M_IOV); 493 return (error); 494 } 495 496 int 497 kern_writev(struct thread *td, int fd, struct uio *auio) 498 { 499 struct file *fp; 500 cap_rights_t rights; 501 int error; 502 503 error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp); 504 if (error) 505 return (error); 506 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 507 fdrop(fp, td); 508 return (error); 509 } 510 511 /* 512 * Gather positioned write system call. 513 */ 514 #ifndef _SYS_SYSPROTO_H_ 515 struct pwritev_args { 516 int fd; 517 struct iovec *iovp; 518 u_int iovcnt; 519 off_t offset; 520 }; 521 #endif 522 int 523 sys_pwritev(struct thread *td, struct pwritev_args *uap) 524 { 525 struct uio *auio; 526 int error; 527 528 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 529 if (error) 530 return (error); 531 error = kern_pwritev(td, uap->fd, auio, uap->offset); 532 free(auio, M_IOV); 533 return (error); 534 } 535 536 int 537 kern_pwritev(td, fd, auio, offset) 538 struct thread *td; 539 struct uio *auio; 540 int fd; 541 off_t offset; 542 { 543 struct file *fp; 544 cap_rights_t rights; 545 int error; 546 547 error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp); 548 if (error) 549 return (error); 550 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 551 error = ESPIPE; 552 else if (offset < 0 && 553 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) 554 error = EINVAL; 555 else 556 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 557 fdrop(fp, td); 558 return (error); 559 } 560 561 /* 562 * Common code for writev and pwritev that writes data to 563 * a file using the passed in uio, offset, and flags. 564 */ 565 static int 566 dofilewrite(td, fd, fp, auio, offset, flags) 567 struct thread *td; 568 int fd; 569 struct file *fp; 570 struct uio *auio; 571 off_t offset; 572 int flags; 573 { 574 ssize_t cnt; 575 int error; 576 #ifdef KTRACE 577 struct uio *ktruio = NULL; 578 #endif 579 580 AUDIT_ARG_FD(fd); 581 auio->uio_rw = UIO_WRITE; 582 auio->uio_td = td; 583 auio->uio_offset = offset; 584 #ifdef KTRACE 585 if (KTRPOINT(td, KTR_GENIO)) 586 ktruio = cloneuio(auio); 587 #endif 588 cnt = auio->uio_resid; 589 if (fp->f_type == DTYPE_VNODE && 590 (fp->f_vnread_flags & FDEVFS_VNODE) == 0) 591 bwillwrite(); 592 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 593 if (auio->uio_resid != cnt && (error == ERESTART || 594 error == EINTR || error == EWOULDBLOCK)) 595 error = 0; 596 /* Socket layer is responsible for issuing SIGPIPE. */ 597 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 598 PROC_LOCK(td->td_proc); 599 tdsignal(td, SIGPIPE); 600 PROC_UNLOCK(td->td_proc); 601 } 602 } 603 cnt -= auio->uio_resid; 604 #ifdef KTRACE 605 if (ktruio != NULL) { 606 ktruio->uio_resid = cnt; 607 ktrgenio(fd, UIO_WRITE, ktruio, error); 608 } 609 #endif 610 td->td_retval[0] = cnt; 611 return (error); 612 } 613 614 /* 615 * Truncate a file given a file descriptor. 616 * 617 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 618 * descriptor isn't writable. 619 */ 620 int 621 kern_ftruncate(td, fd, length) 622 struct thread *td; 623 int fd; 624 off_t length; 625 { 626 struct file *fp; 627 cap_rights_t rights; 628 int error; 629 630 AUDIT_ARG_FD(fd); 631 if (length < 0) 632 return (EINVAL); 633 error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp); 634 if (error) 635 return (error); 636 AUDIT_ARG_FILE(td->td_proc, fp); 637 if (!(fp->f_flag & FWRITE)) { 638 fdrop(fp, td); 639 return (EINVAL); 640 } 641 error = fo_truncate(fp, length, td->td_ucred, td); 642 fdrop(fp, td); 643 return (error); 644 } 645 646 #ifndef _SYS_SYSPROTO_H_ 647 struct ftruncate_args { 648 int fd; 649 int pad; 650 off_t length; 651 }; 652 #endif 653 int 654 sys_ftruncate(td, uap) 655 struct thread *td; 656 struct ftruncate_args *uap; 657 { 658 659 return (kern_ftruncate(td, uap->fd, uap->length)); 660 } 661 662 #if defined(COMPAT_43) 663 #ifndef _SYS_SYSPROTO_H_ 664 struct oftruncate_args { 665 int fd; 666 long length; 667 }; 668 #endif 669 int 670 oftruncate(td, uap) 671 struct thread *td; 672 struct oftruncate_args *uap; 673 { 674 675 return (kern_ftruncate(td, uap->fd, uap->length)); 676 } 677 #endif /* COMPAT_43 */ 678 679 #ifndef _SYS_SYSPROTO_H_ 680 struct ioctl_args { 681 int fd; 682 u_long com; 683 caddr_t data; 684 }; 685 #endif 686 /* ARGSUSED */ 687 int 688 sys_ioctl(struct thread *td, struct ioctl_args *uap) 689 { 690 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); 691 uint32_t com; 692 int arg, error; 693 u_int size; 694 caddr_t data; 695 696 #ifdef INVARIANTS 697 if (uap->com > 0xffffffff) { 698 printf( 699 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 700 td->td_proc->p_pid, td->td_name, uap->com); 701 } 702 #endif 703 com = (uint32_t)uap->com; 704 705 /* 706 * Interpret high order word to find amount of data to be 707 * copied to/from the user's address space. 708 */ 709 size = IOCPARM_LEN(com); 710 if ((size > IOCPARM_MAX) || 711 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 712 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 713 ((com & IOC_OUT) && size == 0) || 714 #else 715 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 716 #endif 717 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 718 return (ENOTTY); 719 720 if (size > 0) { 721 if (com & IOC_VOID) { 722 /* Integer argument. */ 723 arg = (intptr_t)uap->data; 724 data = (void *)&arg; 725 size = 0; 726 } else { 727 if (size > SYS_IOCTL_SMALL_SIZE) 728 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 729 else 730 data = smalldata; 731 } 732 } else 733 data = (void *)&uap->data; 734 if (com & IOC_IN) { 735 error = copyin(uap->data, data, (u_int)size); 736 if (error != 0) 737 goto out; 738 } else if (com & IOC_OUT) { 739 /* 740 * Zero the buffer so the user always 741 * gets back something deterministic. 742 */ 743 bzero(data, size); 744 } 745 746 error = kern_ioctl(td, uap->fd, com, data); 747 748 if (error == 0 && (com & IOC_OUT)) 749 error = copyout(data, uap->data, (u_int)size); 750 751 out: 752 if (size > SYS_IOCTL_SMALL_SIZE) 753 free(data, M_IOCTLOPS); 754 return (error); 755 } 756 757 int 758 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 759 { 760 struct file *fp; 761 struct filedesc *fdp; 762 #ifndef CAPABILITIES 763 cap_rights_t rights; 764 #endif 765 int error, tmp, locked; 766 767 AUDIT_ARG_FD(fd); 768 AUDIT_ARG_CMD(com); 769 770 fdp = td->td_proc->p_fd; 771 772 switch (com) { 773 case FIONCLEX: 774 case FIOCLEX: 775 FILEDESC_XLOCK(fdp); 776 locked = LA_XLOCKED; 777 break; 778 default: 779 #ifdef CAPABILITIES 780 FILEDESC_SLOCK(fdp); 781 locked = LA_SLOCKED; 782 #else 783 locked = LA_UNLOCKED; 784 #endif 785 break; 786 } 787 788 #ifdef CAPABILITIES 789 if ((fp = fget_locked(fdp, fd)) == NULL) { 790 error = EBADF; 791 goto out; 792 } 793 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 794 fp = NULL; /* fhold() was not called yet */ 795 goto out; 796 } 797 fhold(fp); 798 if (locked == LA_SLOCKED) { 799 FILEDESC_SUNLOCK(fdp); 800 locked = LA_UNLOCKED; 801 } 802 #else 803 error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp); 804 if (error != 0) { 805 fp = NULL; 806 goto out; 807 } 808 #endif 809 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 810 error = EBADF; 811 goto out; 812 } 813 814 switch (com) { 815 case FIONCLEX: 816 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 817 goto out; 818 case FIOCLEX: 819 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 820 goto out; 821 case FIONBIO: 822 if ((tmp = *(int *)data)) 823 atomic_set_int(&fp->f_flag, FNONBLOCK); 824 else 825 atomic_clear_int(&fp->f_flag, FNONBLOCK); 826 data = (void *)&tmp; 827 break; 828 case FIOASYNC: 829 if ((tmp = *(int *)data)) 830 atomic_set_int(&fp->f_flag, FASYNC); 831 else 832 atomic_clear_int(&fp->f_flag, FASYNC); 833 data = (void *)&tmp; 834 break; 835 } 836 837 error = fo_ioctl(fp, com, data, td->td_ucred, td); 838 out: 839 switch (locked) { 840 case LA_XLOCKED: 841 FILEDESC_XUNLOCK(fdp); 842 break; 843 #ifdef CAPABILITIES 844 case LA_SLOCKED: 845 FILEDESC_SUNLOCK(fdp); 846 break; 847 #endif 848 default: 849 FILEDESC_UNLOCK_ASSERT(fdp); 850 break; 851 } 852 if (fp != NULL) 853 fdrop(fp, td); 854 return (error); 855 } 856 857 int 858 poll_no_poll(int events) 859 { 860 /* 861 * Return true for read/write. If the user asked for something 862 * special, return POLLNVAL, so that clients have a way of 863 * determining reliably whether or not the extended 864 * functionality is present without hard-coding knowledge 865 * of specific filesystem implementations. 866 */ 867 if (events & ~POLLSTANDARD) 868 return (POLLNVAL); 869 870 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 871 } 872 873 int 874 sys_pselect(struct thread *td, struct pselect_args *uap) 875 { 876 struct timespec ts; 877 struct timeval tv, *tvp; 878 sigset_t set, *uset; 879 int error; 880 881 if (uap->ts != NULL) { 882 error = copyin(uap->ts, &ts, sizeof(ts)); 883 if (error != 0) 884 return (error); 885 TIMESPEC_TO_TIMEVAL(&tv, &ts); 886 tvp = &tv; 887 } else 888 tvp = NULL; 889 if (uap->sm != NULL) { 890 error = copyin(uap->sm, &set, sizeof(set)); 891 if (error != 0) 892 return (error); 893 uset = &set; 894 } else 895 uset = NULL; 896 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 897 uset, NFDBITS)); 898 } 899 900 int 901 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 902 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 903 { 904 int error; 905 906 if (uset != NULL) { 907 error = kern_sigprocmask(td, SIG_SETMASK, uset, 908 &td->td_oldsigmask, 0); 909 if (error != 0) 910 return (error); 911 td->td_pflags |= TDP_OLDMASK; 912 /* 913 * Make sure that ast() is called on return to 914 * usermode and TDP_OLDMASK is cleared, restoring old 915 * sigmask. 916 */ 917 thread_lock(td); 918 td->td_flags |= TDF_ASTPENDING; 919 thread_unlock(td); 920 } 921 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 922 return (error); 923 } 924 925 #ifndef _SYS_SYSPROTO_H_ 926 struct select_args { 927 int nd; 928 fd_set *in, *ou, *ex; 929 struct timeval *tv; 930 }; 931 #endif 932 int 933 sys_select(struct thread *td, struct select_args *uap) 934 { 935 struct timeval tv, *tvp; 936 int error; 937 938 if (uap->tv != NULL) { 939 error = copyin(uap->tv, &tv, sizeof(tv)); 940 if (error) 941 return (error); 942 tvp = &tv; 943 } else 944 tvp = NULL; 945 946 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 947 NFDBITS)); 948 } 949 950 /* 951 * In the unlikely case when user specified n greater then the last 952 * open file descriptor, check that no bits are set after the last 953 * valid fd. We must return EBADF if any is set. 954 * 955 * There are applications that rely on the behaviour. 956 * 957 * nd is fd_lastfile + 1. 958 */ 959 static int 960 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 961 { 962 char *addr, *oaddr; 963 int b, i, res; 964 uint8_t bits; 965 966 if (nd >= ndu || fd_in == NULL) 967 return (0); 968 969 oaddr = NULL; 970 bits = 0; /* silence gcc */ 971 for (i = nd; i < ndu; i++) { 972 b = i / NBBY; 973 #if BYTE_ORDER == LITTLE_ENDIAN 974 addr = (char *)fd_in + b; 975 #else 976 addr = (char *)fd_in; 977 if (abi_nfdbits == NFDBITS) { 978 addr += rounddown(b, sizeof(fd_mask)) + 979 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 980 } else { 981 addr += rounddown(b, sizeof(uint32_t)) + 982 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 983 } 984 #endif 985 if (addr != oaddr) { 986 res = fubyte(addr); 987 if (res == -1) 988 return (EFAULT); 989 oaddr = addr; 990 bits = res; 991 } 992 if ((bits & (1 << (i % NBBY))) != 0) 993 return (EBADF); 994 } 995 return (0); 996 } 997 998 int 999 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 1000 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 1001 { 1002 struct filedesc *fdp; 1003 /* 1004 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 1005 * infds with the new FD_SETSIZE of 1024, and more than enough for 1006 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 1007 * of 256. 1008 */ 1009 fd_mask s_selbits[howmany(2048, NFDBITS)]; 1010 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 1011 struct timeval rtv; 1012 sbintime_t asbt, precision, rsbt; 1013 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 1014 int error, lf, ndu; 1015 1016 if (nd < 0) 1017 return (EINVAL); 1018 fdp = td->td_proc->p_fd; 1019 ndu = nd; 1020 lf = fdp->fd_lastfile; 1021 if (nd > lf + 1) 1022 nd = lf + 1; 1023 1024 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 1025 if (error != 0) 1026 return (error); 1027 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 1028 if (error != 0) 1029 return (error); 1030 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 1031 if (error != 0) 1032 return (error); 1033 1034 /* 1035 * Allocate just enough bits for the non-null fd_sets. Use the 1036 * preallocated auto buffer if possible. 1037 */ 1038 nfdbits = roundup(nd, NFDBITS); 1039 ncpbytes = nfdbits / NBBY; 1040 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 1041 nbufbytes = 0; 1042 if (fd_in != NULL) 1043 nbufbytes += 2 * ncpbytes; 1044 if (fd_ou != NULL) 1045 nbufbytes += 2 * ncpbytes; 1046 if (fd_ex != NULL) 1047 nbufbytes += 2 * ncpbytes; 1048 if (nbufbytes <= sizeof s_selbits) 1049 selbits = &s_selbits[0]; 1050 else 1051 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1052 1053 /* 1054 * Assign pointers into the bit buffers and fetch the input bits. 1055 * Put the output buffers together so that they can be bzeroed 1056 * together. 1057 */ 1058 sbp = selbits; 1059 #define getbits(name, x) \ 1060 do { \ 1061 if (name == NULL) { \ 1062 ibits[x] = NULL; \ 1063 obits[x] = NULL; \ 1064 } else { \ 1065 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1066 obits[x] = sbp; \ 1067 sbp += ncpbytes / sizeof *sbp; \ 1068 error = copyin(name, ibits[x], ncpubytes); \ 1069 if (error != 0) \ 1070 goto done; \ 1071 bzero((char *)ibits[x] + ncpubytes, \ 1072 ncpbytes - ncpubytes); \ 1073 } \ 1074 } while (0) 1075 getbits(fd_in, 0); 1076 getbits(fd_ou, 1); 1077 getbits(fd_ex, 2); 1078 #undef getbits 1079 1080 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1081 /* 1082 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1083 * we are running under 32-bit emulation. This should be more 1084 * generic. 1085 */ 1086 #define swizzle_fdset(bits) \ 1087 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1088 int i; \ 1089 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1090 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1091 } 1092 #else 1093 #define swizzle_fdset(bits) 1094 #endif 1095 1096 /* Make sure the bit order makes it through an ABI transition */ 1097 swizzle_fdset(ibits[0]); 1098 swizzle_fdset(ibits[1]); 1099 swizzle_fdset(ibits[2]); 1100 1101 if (nbufbytes != 0) 1102 bzero(selbits, nbufbytes / 2); 1103 1104 precision = 0; 1105 if (tvp != NULL) { 1106 rtv = *tvp; 1107 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1108 rtv.tv_usec >= 1000000) { 1109 error = EINVAL; 1110 goto done; 1111 } 1112 if (!timevalisset(&rtv)) 1113 asbt = 0; 1114 else if (rtv.tv_sec <= INT32_MAX) { 1115 rsbt = tvtosbt(rtv); 1116 precision = rsbt; 1117 precision >>= tc_precexp; 1118 if (TIMESEL(&asbt, rsbt)) 1119 asbt += tc_tick_sbt; 1120 if (asbt <= SBT_MAX - rsbt) 1121 asbt += rsbt; 1122 else 1123 asbt = -1; 1124 } else 1125 asbt = -1; 1126 } else 1127 asbt = -1; 1128 seltdinit(td); 1129 /* Iterate until the timeout expires or descriptors become ready. */ 1130 for (;;) { 1131 error = selscan(td, ibits, obits, nd); 1132 if (error || td->td_retval[0] != 0) 1133 break; 1134 error = seltdwait(td, asbt, precision); 1135 if (error) 1136 break; 1137 error = selrescan(td, ibits, obits); 1138 if (error || td->td_retval[0] != 0) 1139 break; 1140 } 1141 seltdclear(td); 1142 1143 done: 1144 /* select is not restarted after signals... */ 1145 if (error == ERESTART) 1146 error = EINTR; 1147 if (error == EWOULDBLOCK) 1148 error = 0; 1149 1150 /* swizzle bit order back, if necessary */ 1151 swizzle_fdset(obits[0]); 1152 swizzle_fdset(obits[1]); 1153 swizzle_fdset(obits[2]); 1154 #undef swizzle_fdset 1155 1156 #define putbits(name, x) \ 1157 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1158 error = error2; 1159 if (error == 0) { 1160 int error2; 1161 1162 putbits(fd_in, 0); 1163 putbits(fd_ou, 1); 1164 putbits(fd_ex, 2); 1165 #undef putbits 1166 } 1167 if (selbits != &s_selbits[0]) 1168 free(selbits, M_SELECT); 1169 1170 return (error); 1171 } 1172 /* 1173 * Convert a select bit set to poll flags. 1174 * 1175 * The backend always returns POLLHUP/POLLERR if appropriate and we 1176 * return this as a set bit in any set. 1177 */ 1178 static int select_flags[3] = { 1179 POLLRDNORM | POLLHUP | POLLERR, 1180 POLLWRNORM | POLLHUP | POLLERR, 1181 POLLRDBAND | POLLERR 1182 }; 1183 1184 /* 1185 * Compute the fo_poll flags required for a fd given by the index and 1186 * bit position in the fd_mask array. 1187 */ 1188 static __inline int 1189 selflags(fd_mask **ibits, int idx, fd_mask bit) 1190 { 1191 int flags; 1192 int msk; 1193 1194 flags = 0; 1195 for (msk = 0; msk < 3; msk++) { 1196 if (ibits[msk] == NULL) 1197 continue; 1198 if ((ibits[msk][idx] & bit) == 0) 1199 continue; 1200 flags |= select_flags[msk]; 1201 } 1202 return (flags); 1203 } 1204 1205 /* 1206 * Set the appropriate output bits given a mask of fired events and the 1207 * input bits originally requested. 1208 */ 1209 static __inline int 1210 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1211 { 1212 int msk; 1213 int n; 1214 1215 n = 0; 1216 for (msk = 0; msk < 3; msk++) { 1217 if ((events & select_flags[msk]) == 0) 1218 continue; 1219 if (ibits[msk] == NULL) 1220 continue; 1221 if ((ibits[msk][idx] & bit) == 0) 1222 continue; 1223 /* 1224 * XXX Check for a duplicate set. This can occur because a 1225 * socket calls selrecord() twice for each poll() call 1226 * resulting in two selfds per real fd. selrescan() will 1227 * call selsetbits twice as a result. 1228 */ 1229 if ((obits[msk][idx] & bit) != 0) 1230 continue; 1231 obits[msk][idx] |= bit; 1232 n++; 1233 } 1234 1235 return (n); 1236 } 1237 1238 static __inline int 1239 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) 1240 { 1241 cap_rights_t rights; 1242 1243 cap_rights_init(&rights, CAP_EVENT); 1244 1245 return (fget_unlocked(fdp, fd, &rights, fpp, NULL)); 1246 } 1247 1248 /* 1249 * Traverse the list of fds attached to this thread's seltd and check for 1250 * completion. 1251 */ 1252 static int 1253 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1254 { 1255 struct filedesc *fdp; 1256 struct selinfo *si; 1257 struct seltd *stp; 1258 struct selfd *sfp; 1259 struct selfd *sfn; 1260 struct file *fp; 1261 fd_mask bit; 1262 int fd, ev, n, idx; 1263 int error; 1264 1265 fdp = td->td_proc->p_fd; 1266 stp = td->td_sel; 1267 n = 0; 1268 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1269 fd = (int)(uintptr_t)sfp->sf_cookie; 1270 si = sfp->sf_si; 1271 selfdfree(stp, sfp); 1272 /* If the selinfo wasn't cleared the event didn't fire. */ 1273 if (si != NULL) 1274 continue; 1275 error = getselfd_cap(fdp, fd, &fp); 1276 if (error) 1277 return (error); 1278 idx = fd / NFDBITS; 1279 bit = (fd_mask)1 << (fd % NFDBITS); 1280 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1281 fdrop(fp, td); 1282 if (ev != 0) 1283 n += selsetbits(ibits, obits, idx, bit, ev); 1284 } 1285 stp->st_flags = 0; 1286 td->td_retval[0] = n; 1287 return (0); 1288 } 1289 1290 /* 1291 * Perform the initial filedescriptor scan and register ourselves with 1292 * each selinfo. 1293 */ 1294 static int 1295 selscan(td, ibits, obits, nfd) 1296 struct thread *td; 1297 fd_mask **ibits, **obits; 1298 int nfd; 1299 { 1300 struct filedesc *fdp; 1301 struct file *fp; 1302 fd_mask bit; 1303 int ev, flags, end, fd; 1304 int n, idx; 1305 int error; 1306 1307 fdp = td->td_proc->p_fd; 1308 n = 0; 1309 for (idx = 0, fd = 0; fd < nfd; idx++) { 1310 end = imin(fd + NFDBITS, nfd); 1311 for (bit = 1; fd < end; bit <<= 1, fd++) { 1312 /* Compute the list of events we're interested in. */ 1313 flags = selflags(ibits, idx, bit); 1314 if (flags == 0) 1315 continue; 1316 error = getselfd_cap(fdp, fd, &fp); 1317 if (error) 1318 return (error); 1319 selfdalloc(td, (void *)(uintptr_t)fd); 1320 ev = fo_poll(fp, flags, td->td_ucred, td); 1321 fdrop(fp, td); 1322 if (ev != 0) 1323 n += selsetbits(ibits, obits, idx, bit, ev); 1324 } 1325 } 1326 1327 td->td_retval[0] = n; 1328 return (0); 1329 } 1330 1331 int 1332 sys_poll(struct thread *td, struct poll_args *uap) 1333 { 1334 struct timespec ts, *tsp; 1335 1336 if (uap->timeout != INFTIM) { 1337 if (uap->timeout < 0) 1338 return (EINVAL); 1339 ts.tv_sec = uap->timeout / 1000; 1340 ts.tv_nsec = (uap->timeout % 1000) * 1000000; 1341 tsp = &ts; 1342 } else 1343 tsp = NULL; 1344 1345 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); 1346 } 1347 1348 int 1349 kern_poll(struct thread *td, struct pollfd *fds, u_int nfds, 1350 struct timespec *tsp, sigset_t *uset) 1351 { 1352 struct pollfd *bits; 1353 struct pollfd smallbits[32]; 1354 sbintime_t sbt, precision, tmp; 1355 time_t over; 1356 struct timespec ts; 1357 int error; 1358 size_t ni; 1359 1360 precision = 0; 1361 if (tsp != NULL) { 1362 if (tsp->tv_sec < 0) 1363 return (EINVAL); 1364 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000) 1365 return (EINVAL); 1366 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1367 sbt = 0; 1368 else { 1369 ts = *tsp; 1370 if (ts.tv_sec > INT32_MAX / 2) { 1371 over = ts.tv_sec - INT32_MAX / 2; 1372 ts.tv_sec -= over; 1373 } else 1374 over = 0; 1375 tmp = tstosbt(ts); 1376 precision = tmp; 1377 precision >>= tc_precexp; 1378 if (TIMESEL(&sbt, tmp)) 1379 sbt += tc_tick_sbt; 1380 sbt += tmp; 1381 } 1382 } else 1383 sbt = -1; 1384 1385 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1386 return (EINVAL); 1387 ni = nfds * sizeof(struct pollfd); 1388 if (ni > sizeof(smallbits)) 1389 bits = malloc(ni, M_TEMP, M_WAITOK); 1390 else 1391 bits = smallbits; 1392 error = copyin(fds, bits, ni); 1393 if (error) 1394 goto done; 1395 1396 if (uset != NULL) { 1397 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1398 &td->td_oldsigmask, 0); 1399 if (error) 1400 goto done; 1401 td->td_pflags |= TDP_OLDMASK; 1402 /* 1403 * Make sure that ast() is called on return to 1404 * usermode and TDP_OLDMASK is cleared, restoring old 1405 * sigmask. 1406 */ 1407 thread_lock(td); 1408 td->td_flags |= TDF_ASTPENDING; 1409 thread_unlock(td); 1410 } 1411 1412 seltdinit(td); 1413 /* Iterate until the timeout expires or descriptors become ready. */ 1414 for (;;) { 1415 error = pollscan(td, bits, nfds); 1416 if (error || td->td_retval[0] != 0) 1417 break; 1418 error = seltdwait(td, sbt, precision); 1419 if (error) 1420 break; 1421 error = pollrescan(td); 1422 if (error || td->td_retval[0] != 0) 1423 break; 1424 } 1425 seltdclear(td); 1426 1427 done: 1428 /* poll is not restarted after signals... */ 1429 if (error == ERESTART) 1430 error = EINTR; 1431 if (error == EWOULDBLOCK) 1432 error = 0; 1433 if (error == 0) { 1434 error = pollout(td, bits, fds, nfds); 1435 if (error) 1436 goto out; 1437 } 1438 out: 1439 if (ni > sizeof(smallbits)) 1440 free(bits, M_TEMP); 1441 return (error); 1442 } 1443 1444 int 1445 sys_ppoll(struct thread *td, struct ppoll_args *uap) 1446 { 1447 struct timespec ts, *tsp; 1448 sigset_t set, *ssp; 1449 int error; 1450 1451 if (uap->ts != NULL) { 1452 error = copyin(uap->ts, &ts, sizeof(ts)); 1453 if (error) 1454 return (error); 1455 tsp = &ts; 1456 } else 1457 tsp = NULL; 1458 if (uap->set != NULL) { 1459 error = copyin(uap->set, &set, sizeof(set)); 1460 if (error) 1461 return (error); 1462 ssp = &set; 1463 } else 1464 ssp = NULL; 1465 /* 1466 * fds is still a pointer to user space. kern_poll() will 1467 * take care of copyin that array to the kernel space. 1468 */ 1469 1470 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); 1471 } 1472 1473 static int 1474 pollrescan(struct thread *td) 1475 { 1476 struct seltd *stp; 1477 struct selfd *sfp; 1478 struct selfd *sfn; 1479 struct selinfo *si; 1480 struct filedesc *fdp; 1481 struct file *fp; 1482 struct pollfd *fd; 1483 #ifdef CAPABILITIES 1484 cap_rights_t rights; 1485 #endif 1486 int n; 1487 1488 n = 0; 1489 fdp = td->td_proc->p_fd; 1490 stp = td->td_sel; 1491 FILEDESC_SLOCK(fdp); 1492 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1493 fd = (struct pollfd *)sfp->sf_cookie; 1494 si = sfp->sf_si; 1495 selfdfree(stp, sfp); 1496 /* If the selinfo wasn't cleared the event didn't fire. */ 1497 if (si != NULL) 1498 continue; 1499 fp = fdp->fd_ofiles[fd->fd].fde_file; 1500 #ifdef CAPABILITIES 1501 if (fp == NULL || 1502 cap_check(cap_rights(fdp, fd->fd), 1503 cap_rights_init(&rights, CAP_EVENT)) != 0) 1504 #else 1505 if (fp == NULL) 1506 #endif 1507 { 1508 fd->revents = POLLNVAL; 1509 n++; 1510 continue; 1511 } 1512 1513 /* 1514 * Note: backend also returns POLLHUP and 1515 * POLLERR if appropriate. 1516 */ 1517 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1518 if (fd->revents != 0) 1519 n++; 1520 } 1521 FILEDESC_SUNLOCK(fdp); 1522 stp->st_flags = 0; 1523 td->td_retval[0] = n; 1524 return (0); 1525 } 1526 1527 1528 static int 1529 pollout(td, fds, ufds, nfd) 1530 struct thread *td; 1531 struct pollfd *fds; 1532 struct pollfd *ufds; 1533 u_int nfd; 1534 { 1535 int error = 0; 1536 u_int i = 0; 1537 u_int n = 0; 1538 1539 for (i = 0; i < nfd; i++) { 1540 error = copyout(&fds->revents, &ufds->revents, 1541 sizeof(ufds->revents)); 1542 if (error) 1543 return (error); 1544 if (fds->revents != 0) 1545 n++; 1546 fds++; 1547 ufds++; 1548 } 1549 td->td_retval[0] = n; 1550 return (0); 1551 } 1552 1553 static int 1554 pollscan(td, fds, nfd) 1555 struct thread *td; 1556 struct pollfd *fds; 1557 u_int nfd; 1558 { 1559 struct filedesc *fdp = td->td_proc->p_fd; 1560 struct file *fp; 1561 #ifdef CAPABILITIES 1562 cap_rights_t rights; 1563 #endif 1564 int i, n = 0; 1565 1566 FILEDESC_SLOCK(fdp); 1567 for (i = 0; i < nfd; i++, fds++) { 1568 if (fds->fd > fdp->fd_lastfile) { 1569 fds->revents = POLLNVAL; 1570 n++; 1571 } else if (fds->fd < 0) { 1572 fds->revents = 0; 1573 } else { 1574 fp = fdp->fd_ofiles[fds->fd].fde_file; 1575 #ifdef CAPABILITIES 1576 if (fp == NULL || 1577 cap_check(cap_rights(fdp, fds->fd), 1578 cap_rights_init(&rights, CAP_EVENT)) != 0) 1579 #else 1580 if (fp == NULL) 1581 #endif 1582 { 1583 fds->revents = POLLNVAL; 1584 n++; 1585 } else { 1586 /* 1587 * Note: backend also returns POLLHUP and 1588 * POLLERR if appropriate. 1589 */ 1590 selfdalloc(td, fds); 1591 fds->revents = fo_poll(fp, fds->events, 1592 td->td_ucred, td); 1593 /* 1594 * POSIX requires POLLOUT to be never 1595 * set simultaneously with POLLHUP. 1596 */ 1597 if ((fds->revents & POLLHUP) != 0) 1598 fds->revents &= ~POLLOUT; 1599 1600 if (fds->revents != 0) 1601 n++; 1602 } 1603 } 1604 } 1605 FILEDESC_SUNLOCK(fdp); 1606 td->td_retval[0] = n; 1607 return (0); 1608 } 1609 1610 /* 1611 * OpenBSD poll system call. 1612 * 1613 * XXX this isn't quite a true representation.. OpenBSD uses select ops. 1614 */ 1615 #ifndef _SYS_SYSPROTO_H_ 1616 struct openbsd_poll_args { 1617 struct pollfd *fds; 1618 u_int nfds; 1619 int timeout; 1620 }; 1621 #endif 1622 int 1623 sys_openbsd_poll(td, uap) 1624 register struct thread *td; 1625 register struct openbsd_poll_args *uap; 1626 { 1627 return (sys_poll(td, (struct poll_args *)uap)); 1628 } 1629 1630 /* 1631 * XXX This was created specifically to support netncp and netsmb. This 1632 * allows the caller to specify a socket to wait for events on. It returns 1633 * 0 if any events matched and an error otherwise. There is no way to 1634 * determine which events fired. 1635 */ 1636 int 1637 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1638 { 1639 struct timeval rtv; 1640 sbintime_t asbt, precision, rsbt; 1641 int error; 1642 1643 precision = 0; /* stupid gcc! */ 1644 if (tvp != NULL) { 1645 rtv = *tvp; 1646 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1647 rtv.tv_usec >= 1000000) 1648 return (EINVAL); 1649 if (!timevalisset(&rtv)) 1650 asbt = 0; 1651 else if (rtv.tv_sec <= INT32_MAX) { 1652 rsbt = tvtosbt(rtv); 1653 precision = rsbt; 1654 precision >>= tc_precexp; 1655 if (TIMESEL(&asbt, rsbt)) 1656 asbt += tc_tick_sbt; 1657 if (asbt <= SBT_MAX - rsbt) 1658 asbt += rsbt; 1659 else 1660 asbt = -1; 1661 } else 1662 asbt = -1; 1663 } else 1664 asbt = -1; 1665 seltdinit(td); 1666 /* 1667 * Iterate until the timeout expires or the socket becomes ready. 1668 */ 1669 for (;;) { 1670 selfdalloc(td, NULL); 1671 error = sopoll(so, events, NULL, td); 1672 /* error here is actually the ready events. */ 1673 if (error) 1674 return (0); 1675 error = seltdwait(td, asbt, precision); 1676 if (error) 1677 break; 1678 } 1679 seltdclear(td); 1680 /* XXX Duplicates ncp/smb behavior. */ 1681 if (error == ERESTART) 1682 error = 0; 1683 return (error); 1684 } 1685 1686 /* 1687 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1688 * have two select sets, one for read and another for write. 1689 */ 1690 static void 1691 selfdalloc(struct thread *td, void *cookie) 1692 { 1693 struct seltd *stp; 1694 1695 stp = td->td_sel; 1696 if (stp->st_free1 == NULL) 1697 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1698 stp->st_free1->sf_td = stp; 1699 stp->st_free1->sf_cookie = cookie; 1700 if (stp->st_free2 == NULL) 1701 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1702 stp->st_free2->sf_td = stp; 1703 stp->st_free2->sf_cookie = cookie; 1704 } 1705 1706 static void 1707 selfdfree(struct seltd *stp, struct selfd *sfp) 1708 { 1709 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1710 if (sfp->sf_si != NULL) { 1711 mtx_lock(sfp->sf_mtx); 1712 if (sfp->sf_si != NULL) { 1713 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1714 refcount_release(&sfp->sf_refs); 1715 } 1716 mtx_unlock(sfp->sf_mtx); 1717 } 1718 if (refcount_release(&sfp->sf_refs)) 1719 uma_zfree(selfd_zone, sfp); 1720 } 1721 1722 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1723 void 1724 seldrain(sip) 1725 struct selinfo *sip; 1726 { 1727 1728 /* 1729 * This feature is already provided by doselwakeup(), thus it is 1730 * enough to go for it. 1731 * Eventually, the context, should take care to avoid races 1732 * between thread calling select()/poll() and file descriptor 1733 * detaching, but, again, the races are just the same as 1734 * selwakeup(). 1735 */ 1736 doselwakeup(sip, -1); 1737 } 1738 1739 /* 1740 * Record a select request. 1741 */ 1742 void 1743 selrecord(selector, sip) 1744 struct thread *selector; 1745 struct selinfo *sip; 1746 { 1747 struct selfd *sfp; 1748 struct seltd *stp; 1749 struct mtx *mtxp; 1750 1751 stp = selector->td_sel; 1752 /* 1753 * Don't record when doing a rescan. 1754 */ 1755 if (stp->st_flags & SELTD_RESCAN) 1756 return; 1757 /* 1758 * Grab one of the preallocated descriptors. 1759 */ 1760 sfp = NULL; 1761 if ((sfp = stp->st_free1) != NULL) 1762 stp->st_free1 = NULL; 1763 else if ((sfp = stp->st_free2) != NULL) 1764 stp->st_free2 = NULL; 1765 else 1766 panic("selrecord: No free selfd on selq"); 1767 mtxp = sip->si_mtx; 1768 if (mtxp == NULL) 1769 mtxp = mtx_pool_find(mtxpool_select, sip); 1770 /* 1771 * Initialize the sfp and queue it in the thread. 1772 */ 1773 sfp->sf_si = sip; 1774 sfp->sf_mtx = mtxp; 1775 refcount_init(&sfp->sf_refs, 2); 1776 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1777 /* 1778 * Now that we've locked the sip, check for initialization. 1779 */ 1780 mtx_lock(mtxp); 1781 if (sip->si_mtx == NULL) { 1782 sip->si_mtx = mtxp; 1783 TAILQ_INIT(&sip->si_tdlist); 1784 } 1785 /* 1786 * Add this thread to the list of selfds listening on this selinfo. 1787 */ 1788 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1789 mtx_unlock(sip->si_mtx); 1790 } 1791 1792 /* Wake up a selecting thread. */ 1793 void 1794 selwakeup(sip) 1795 struct selinfo *sip; 1796 { 1797 doselwakeup(sip, -1); 1798 } 1799 1800 /* Wake up a selecting thread, and set its priority. */ 1801 void 1802 selwakeuppri(sip, pri) 1803 struct selinfo *sip; 1804 int pri; 1805 { 1806 doselwakeup(sip, pri); 1807 } 1808 1809 /* 1810 * Do a wakeup when a selectable event occurs. 1811 */ 1812 static void 1813 doselwakeup(sip, pri) 1814 struct selinfo *sip; 1815 int pri; 1816 { 1817 struct selfd *sfp; 1818 struct selfd *sfn; 1819 struct seltd *stp; 1820 1821 /* If it's not initialized there can't be any waiters. */ 1822 if (sip->si_mtx == NULL) 1823 return; 1824 /* 1825 * Locking the selinfo locks all selfds associated with it. 1826 */ 1827 mtx_lock(sip->si_mtx); 1828 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1829 /* 1830 * Once we remove this sfp from the list and clear the 1831 * sf_si seltdclear will know to ignore this si. 1832 */ 1833 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1834 sfp->sf_si = NULL; 1835 stp = sfp->sf_td; 1836 mtx_lock(&stp->st_mtx); 1837 stp->st_flags |= SELTD_PENDING; 1838 cv_broadcastpri(&stp->st_wait, pri); 1839 mtx_unlock(&stp->st_mtx); 1840 if (refcount_release(&sfp->sf_refs)) 1841 uma_zfree(selfd_zone, sfp); 1842 } 1843 mtx_unlock(sip->si_mtx); 1844 } 1845 1846 static void 1847 seltdinit(struct thread *td) 1848 { 1849 struct seltd *stp; 1850 1851 if ((stp = td->td_sel) != NULL) 1852 goto out; 1853 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1854 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1855 cv_init(&stp->st_wait, "select"); 1856 out: 1857 stp->st_flags = 0; 1858 STAILQ_INIT(&stp->st_selq); 1859 } 1860 1861 static int 1862 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1863 { 1864 struct seltd *stp; 1865 int error; 1866 1867 stp = td->td_sel; 1868 /* 1869 * An event of interest may occur while we do not hold the seltd 1870 * locked so check the pending flag before we sleep. 1871 */ 1872 mtx_lock(&stp->st_mtx); 1873 /* 1874 * Any further calls to selrecord will be a rescan. 1875 */ 1876 stp->st_flags |= SELTD_RESCAN; 1877 if (stp->st_flags & SELTD_PENDING) { 1878 mtx_unlock(&stp->st_mtx); 1879 return (0); 1880 } 1881 if (sbt == 0) 1882 error = EWOULDBLOCK; 1883 else if (sbt != -1) 1884 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 1885 sbt, precision, C_ABSOLUTE); 1886 else 1887 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1888 mtx_unlock(&stp->st_mtx); 1889 1890 return (error); 1891 } 1892 1893 void 1894 seltdfini(struct thread *td) 1895 { 1896 struct seltd *stp; 1897 1898 stp = td->td_sel; 1899 if (stp == NULL) 1900 return; 1901 if (stp->st_free1) 1902 uma_zfree(selfd_zone, stp->st_free1); 1903 if (stp->st_free2) 1904 uma_zfree(selfd_zone, stp->st_free2); 1905 td->td_sel = NULL; 1906 cv_destroy(&stp->st_wait); 1907 mtx_destroy(&stp->st_mtx); 1908 free(stp, M_SELECT); 1909 } 1910 1911 /* 1912 * Remove the references to the thread from all of the objects we were 1913 * polling. 1914 */ 1915 static void 1916 seltdclear(struct thread *td) 1917 { 1918 struct seltd *stp; 1919 struct selfd *sfp; 1920 struct selfd *sfn; 1921 1922 stp = td->td_sel; 1923 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1924 selfdfree(stp, sfp); 1925 stp->st_flags = 0; 1926 } 1927 1928 static void selectinit(void *); 1929 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1930 static void 1931 selectinit(void *dummy __unused) 1932 { 1933 1934 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, 1935 NULL, NULL, UMA_ALIGN_PTR, 0); 1936 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 1937 } 1938 1939 /* 1940 * Set up a syscall return value that follows the convention specified for 1941 * posix_* functions. 1942 */ 1943 int 1944 kern_posix_error(struct thread *td, int error) 1945 { 1946 1947 if (error <= 0) 1948 return (error); 1949 td->td_errno = error; 1950 td->td_pflags |= TDP_NERRNO; 1951 td->td_retval[0] = error; 1952 return (0); 1953 }
Cache object: a227e17b3b952da4224e2f9c3afee477
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