1 /* $OpenBSD: kern_descrip.c,v 1.203 2021/10/21 09:59:13 claudio Exp $ */ 2 /* $NetBSD: kern_descrip.c,v 1.42 1996/03/30 22:24:38 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 38 */ 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/filedesc.h> 43 #include <sys/kernel.h> 44 #include <sys/vnode.h> 45 #include <sys/proc.h> 46 #include <sys/file.h> 47 #include <sys/socket.h> 48 #include <sys/socketvar.h> 49 #include <sys/stat.h> 50 #include <sys/ioctl.h> 51 #include <sys/fcntl.h> 52 #include <sys/lock.h> 53 #include <sys/malloc.h> 54 #include <sys/syslog.h> 55 #include <sys/ucred.h> 56 #include <sys/unistd.h> 57 #include <sys/resourcevar.h> 58 #include <sys/mount.h> 59 #include <sys/syscallargs.h> 60 #include <sys/event.h> 61 #include <sys/pool.h> 62 #include <sys/ktrace.h> 63 #include <sys/pledge.h> 64 65 #include <sys/pipe.h> 66 67 /* 68 * Descriptor management. 69 * 70 * We need to block interrupts as long as `fhdlk' is being taken 71 * with and without the KERNEL_LOCK(). 72 */ 73 struct mutex fhdlk = MUTEX_INITIALIZER(IPL_MPFLOOR); 74 struct filelist filehead; /* head of list of open files */ 75 int numfiles; /* actual number of open files */ 76 77 static __inline void fd_used(struct filedesc *, int); 78 static __inline void fd_unused(struct filedesc *, int); 79 static __inline int find_next_zero(u_int *, int, u_int); 80 static __inline int fd_inuse(struct filedesc *, int); 81 int finishdup(struct proc *, struct file *, int, int, register_t *, int); 82 int find_last_set(struct filedesc *, int); 83 int dodup3(struct proc *, int, int, int, register_t *); 84 85 #define DUPF_CLOEXEC 0x01 86 #define DUPF_DUP2 0x02 87 88 struct pool file_pool; 89 struct pool fdesc_pool; 90 91 void 92 filedesc_init(void) 93 { 94 pool_init(&file_pool, sizeof(struct file), 0, IPL_MPFLOOR, 95 PR_WAITOK, "filepl", NULL); 96 pool_init(&fdesc_pool, sizeof(struct filedesc0), 0, IPL_NONE, 97 PR_WAITOK, "fdescpl", NULL); 98 LIST_INIT(&filehead); 99 } 100 101 static __inline int 102 find_next_zero (u_int *bitmap, int want, u_int bits) 103 { 104 int i, off, maxoff; 105 u_int sub; 106 107 if (want > bits) 108 return -1; 109 110 off = want >> NDENTRYSHIFT; 111 i = want & NDENTRYMASK; 112 if (i) { 113 sub = bitmap[off] | ((u_int)~0 >> (NDENTRIES - i)); 114 if (sub != ~0) 115 goto found; 116 off++; 117 } 118 119 maxoff = NDLOSLOTS(bits); 120 while (off < maxoff) { 121 if ((sub = bitmap[off]) != ~0) 122 goto found; 123 off++; 124 } 125 126 return -1; 127 128 found: 129 return (off << NDENTRYSHIFT) + ffs(~sub) - 1; 130 } 131 132 int 133 find_last_set(struct filedesc *fd, int last) 134 { 135 int off, i; 136 u_int *bitmap = fd->fd_lomap; 137 138 off = (last - 1) >> NDENTRYSHIFT; 139 140 while (off >= 0 && !bitmap[off]) 141 off--; 142 if (off < 0) 143 return 0; 144 145 i = ((off + 1) << NDENTRYSHIFT) - 1; 146 if (i >= last) 147 i = last - 1; 148 149 while (i > 0 && !fd_inuse(fd, i)) 150 i--; 151 return i; 152 } 153 154 static __inline int 155 fd_inuse(struct filedesc *fdp, int fd) 156 { 157 u_int off = fd >> NDENTRYSHIFT; 158 159 if (fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) 160 return 1; 161 162 return 0; 163 } 164 165 static __inline void 166 fd_used(struct filedesc *fdp, int fd) 167 { 168 u_int off = fd >> NDENTRYSHIFT; 169 170 fdp->fd_lomap[off] |= 1 << (fd & NDENTRYMASK); 171 if (fdp->fd_lomap[off] == ~0) 172 fdp->fd_himap[off >> NDENTRYSHIFT] |= 1 << (off & NDENTRYMASK); 173 174 if (fd > fdp->fd_lastfile) 175 fdp->fd_lastfile = fd; 176 fdp->fd_openfd++; 177 } 178 179 static __inline void 180 fd_unused(struct filedesc *fdp, int fd) 181 { 182 u_int off = fd >> NDENTRYSHIFT; 183 184 if (fd < fdp->fd_freefile) 185 fdp->fd_freefile = fd; 186 187 if (fdp->fd_lomap[off] == ~0) 188 fdp->fd_himap[off >> NDENTRYSHIFT] &= ~(1 << (off & NDENTRYMASK)); 189 fdp->fd_lomap[off] &= ~(1 << (fd & NDENTRYMASK)); 190 191 #ifdef DIAGNOSTIC 192 if (fd > fdp->fd_lastfile) 193 panic("fd_unused: fd_lastfile inconsistent"); 194 #endif 195 if (fd == fdp->fd_lastfile) 196 fdp->fd_lastfile = find_last_set(fdp, fd); 197 fdp->fd_openfd--; 198 } 199 200 struct file * 201 fd_iterfile(struct file *fp, struct proc *p) 202 { 203 struct file *nfp; 204 unsigned int count; 205 206 mtx_enter(&fhdlk); 207 if (fp == NULL) 208 nfp = LIST_FIRST(&filehead); 209 else 210 nfp = LIST_NEXT(fp, f_list); 211 212 /* don't refcount when f_count == 0 to avoid race in fdrop() */ 213 while (nfp != NULL) { 214 count = nfp->f_count; 215 if (count == 0) { 216 nfp = LIST_NEXT(nfp, f_list); 217 continue; 218 } 219 if (atomic_cas_uint(&nfp->f_count, count, count + 1) == count) 220 break; 221 } 222 mtx_leave(&fhdlk); 223 224 if (fp != NULL) 225 FRELE(fp, p); 226 227 return nfp; 228 } 229 230 struct file * 231 fd_getfile(struct filedesc *fdp, int fd) 232 { 233 struct file *fp; 234 235 if ((u_int)fd >= fdp->fd_nfiles) 236 return (NULL); 237 238 mtx_enter(&fdp->fd_fplock); 239 fp = fdp->fd_ofiles[fd]; 240 if (fp != NULL) 241 atomic_inc_int(&fp->f_count); 242 mtx_leave(&fdp->fd_fplock); 243 244 return (fp); 245 } 246 247 struct file * 248 fd_getfile_mode(struct filedesc *fdp, int fd, int mode) 249 { 250 struct file *fp; 251 252 KASSERT(mode != 0); 253 254 fp = fd_getfile(fdp, fd); 255 if (fp == NULL) 256 return (NULL); 257 258 if ((fp->f_flag & mode) == 0) { 259 FRELE(fp, curproc); 260 return (NULL); 261 } 262 263 return (fp); 264 } 265 266 int 267 fd_checkclosed(struct filedesc *fdp, int fd, struct file *fp) 268 { 269 int closed; 270 271 mtx_enter(&fdp->fd_fplock); 272 KASSERT(fd < fdp->fd_nfiles); 273 closed = (fdp->fd_ofiles[fd] != fp); 274 mtx_leave(&fdp->fd_fplock); 275 return (closed); 276 } 277 278 /* 279 * System calls on descriptors. 280 */ 281 282 /* 283 * Duplicate a file descriptor. 284 */ 285 int 286 sys_dup(struct proc *p, void *v, register_t *retval) 287 { 288 struct sys_dup_args /* { 289 syscallarg(int) fd; 290 } */ *uap = v; 291 struct filedesc *fdp = p->p_fd; 292 int old = SCARG(uap, fd); 293 struct file *fp; 294 int new; 295 int error; 296 297 restart: 298 if ((fp = fd_getfile(fdp, old)) == NULL) 299 return (EBADF); 300 fdplock(fdp); 301 if ((error = fdalloc(p, 0, &new)) != 0) { 302 if (error == ENOSPC) { 303 fdexpand(p); 304 fdpunlock(fdp); 305 FRELE(fp, p); 306 goto restart; 307 } 308 fdpunlock(fdp); 309 FRELE(fp, p); 310 return (error); 311 } 312 /* No need for FRELE(), finishdup() uses current ref. */ 313 return (finishdup(p, fp, old, new, retval, 0)); 314 } 315 316 /* 317 * Duplicate a file descriptor to a particular value. 318 */ 319 int 320 sys_dup2(struct proc *p, void *v, register_t *retval) 321 { 322 struct sys_dup2_args /* { 323 syscallarg(int) from; 324 syscallarg(int) to; 325 } */ *uap = v; 326 327 return (dodup3(p, SCARG(uap, from), SCARG(uap, to), 0, retval)); 328 } 329 330 int 331 sys_dup3(struct proc *p, void *v, register_t *retval) 332 { 333 struct sys_dup3_args /* { 334 syscallarg(int) from; 335 syscallarg(int) to; 336 syscallarg(int) flags; 337 } */ *uap = v; 338 339 if (SCARG(uap, from) == SCARG(uap, to)) 340 return (EINVAL); 341 if (SCARG(uap, flags) & ~O_CLOEXEC) 342 return (EINVAL); 343 return (dodup3(p, SCARG(uap, from), SCARG(uap, to), 344 SCARG(uap, flags), retval)); 345 } 346 347 int 348 dodup3(struct proc *p, int old, int new, int flags, register_t *retval) 349 { 350 struct filedesc *fdp = p->p_fd; 351 struct file *fp; 352 int dupflags, error, i; 353 354 restart: 355 if ((fp = fd_getfile(fdp, old)) == NULL) 356 return (EBADF); 357 if (old == new) { 358 /* 359 * NOTE! This doesn't clear the close-on-exec flag. This might 360 * or might not be the intended behavior from the start, but 361 * this is what everyone else does. 362 */ 363 *retval = new; 364 FRELE(fp, p); 365 return (0); 366 } 367 if ((u_int)new >= lim_cur(RLIMIT_NOFILE) || 368 (u_int)new >= maxfiles) { 369 FRELE(fp, p); 370 return (EBADF); 371 } 372 fdplock(fdp); 373 if (new >= fdp->fd_nfiles) { 374 if ((error = fdalloc(p, new, &i)) != 0) { 375 if (error == ENOSPC) { 376 fdexpand(p); 377 fdpunlock(fdp); 378 FRELE(fp, p); 379 goto restart; 380 } 381 fdpunlock(fdp); 382 FRELE(fp, p); 383 return (error); 384 } 385 if (new != i) 386 panic("dup2: fdalloc"); 387 fd_unused(fdp, new); 388 } 389 390 dupflags = DUPF_DUP2; 391 if (flags & O_CLOEXEC) 392 dupflags |= DUPF_CLOEXEC; 393 394 /* No need for FRELE(), finishdup() uses current ref. */ 395 return (finishdup(p, fp, old, new, retval, dupflags)); 396 } 397 398 /* 399 * The file control system call. 400 */ 401 int 402 sys_fcntl(struct proc *p, void *v, register_t *retval) 403 { 404 struct sys_fcntl_args /* { 405 syscallarg(int) fd; 406 syscallarg(int) cmd; 407 syscallarg(void *) arg; 408 } */ *uap = v; 409 int fd = SCARG(uap, fd); 410 struct filedesc *fdp = p->p_fd; 411 struct file *fp; 412 struct vnode *vp; 413 int i, prev, tmp, newmin, flg = F_POSIX; 414 struct flock fl; 415 int error = 0; 416 417 error = pledge_fcntl(p, SCARG(uap, cmd)); 418 if (error) 419 return (error); 420 421 restart: 422 if ((fp = fd_getfile(fdp, fd)) == NULL) 423 return (EBADF); 424 switch (SCARG(uap, cmd)) { 425 426 case F_DUPFD: 427 case F_DUPFD_CLOEXEC: 428 newmin = (long)SCARG(uap, arg); 429 if ((u_int)newmin >= lim_cur(RLIMIT_NOFILE) || 430 (u_int)newmin >= maxfiles) { 431 error = EINVAL; 432 break; 433 } 434 fdplock(fdp); 435 if ((error = fdalloc(p, newmin, &i)) != 0) { 436 if (error == ENOSPC) { 437 fdexpand(p); 438 fdpunlock(fdp); 439 FRELE(fp, p); 440 goto restart; 441 } 442 fdpunlock(fdp); 443 FRELE(fp, p); 444 } else { 445 int dupflags = 0; 446 447 if (SCARG(uap, cmd) == F_DUPFD_CLOEXEC) 448 dupflags |= DUPF_CLOEXEC; 449 450 /* No need for FRELE(), finishdup() uses current ref. */ 451 error = finishdup(p, fp, fd, i, retval, dupflags); 452 } 453 return (error); 454 455 case F_GETFD: 456 fdplock(fdp); 457 *retval = fdp->fd_ofileflags[fd] & UF_EXCLOSE ? 1 : 0; 458 fdpunlock(fdp); 459 break; 460 461 case F_SETFD: 462 fdplock(fdp); 463 if ((long)SCARG(uap, arg) & 1) 464 fdp->fd_ofileflags[fd] |= UF_EXCLOSE; 465 else 466 fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE; 467 fdpunlock(fdp); 468 break; 469 470 case F_GETFL: 471 *retval = OFLAGS(fp->f_flag); 472 break; 473 474 case F_ISATTY: 475 vp = fp->f_data; 476 if (fp->f_type == DTYPE_VNODE && (vp->v_flag & VISTTY)) 477 *retval = 1; 478 else { 479 *retval = 0; 480 error = ENOTTY; 481 } 482 break; 483 484 case F_SETFL: 485 do { 486 tmp = prev = fp->f_flag; 487 tmp &= ~FCNTLFLAGS; 488 tmp |= FFLAGS((long)SCARG(uap, arg)) & FCNTLFLAGS; 489 } while (atomic_cas_uint(&fp->f_flag, prev, tmp) != prev); 490 tmp = fp->f_flag & FNONBLOCK; 491 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 492 if (error) 493 break; 494 tmp = fp->f_flag & FASYNC; 495 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 496 if (!error) 497 break; 498 atomic_clearbits_int(&fp->f_flag, FNONBLOCK); 499 tmp = 0; 500 (void) (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 501 break; 502 503 case F_GETOWN: 504 tmp = 0; 505 error = (*fp->f_ops->fo_ioctl) 506 (fp, FIOGETOWN, (caddr_t)&tmp, p); 507 *retval = tmp; 508 break; 509 510 case F_SETOWN: 511 tmp = (long)SCARG(uap, arg); 512 error = ((*fp->f_ops->fo_ioctl) 513 (fp, FIOSETOWN, (caddr_t)&tmp, p)); 514 break; 515 516 case F_SETLKW: 517 flg |= F_WAIT; 518 /* FALLTHROUGH */ 519 520 case F_SETLK: 521 error = pledge_flock(p); 522 if (error != 0) 523 break; 524 525 if (fp->f_type != DTYPE_VNODE) { 526 error = EINVAL; 527 break; 528 } 529 vp = fp->f_data; 530 /* Copy in the lock structure */ 531 error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&fl, 532 sizeof (fl)); 533 if (error) 534 break; 535 #ifdef KTRACE 536 if (KTRPOINT(p, KTR_STRUCT)) 537 ktrflock(p, &fl); 538 #endif 539 if (fl.l_whence == SEEK_CUR) { 540 off_t offset = foffset(fp); 541 542 if (fl.l_start == 0 && fl.l_len < 0) { 543 /* lockf(3) compliance hack */ 544 fl.l_len = -fl.l_len; 545 fl.l_start = offset - fl.l_len; 546 } else 547 fl.l_start += offset; 548 } 549 switch (fl.l_type) { 550 551 case F_RDLCK: 552 if ((fp->f_flag & FREAD) == 0) { 553 error = EBADF; 554 goto out; 555 } 556 atomic_setbits_int(&fdp->fd_flags, FD_ADVLOCK); 557 error = VOP_ADVLOCK(vp, fdp, F_SETLK, &fl, flg); 558 break; 559 560 case F_WRLCK: 561 if ((fp->f_flag & FWRITE) == 0) { 562 error = EBADF; 563 goto out; 564 } 565 atomic_setbits_int(&fdp->fd_flags, FD_ADVLOCK); 566 error = VOP_ADVLOCK(vp, fdp, F_SETLK, &fl, flg); 567 break; 568 569 case F_UNLCK: 570 error = VOP_ADVLOCK(vp, fdp, F_UNLCK, &fl, F_POSIX); 571 goto out; 572 573 default: 574 error = EINVAL; 575 goto out; 576 } 577 578 if (fd_checkclosed(fdp, fd, fp)) { 579 /* 580 * We have lost the race with close() or dup2(); 581 * unlock, pretend that we've won the race and that 582 * lock had been removed by close() 583 */ 584 fl.l_whence = SEEK_SET; 585 fl.l_start = 0; 586 fl.l_len = 0; 587 VOP_ADVLOCK(vp, fdp, F_UNLCK, &fl, F_POSIX); 588 fl.l_type = F_UNLCK; 589 } 590 goto out; 591 592 593 case F_GETLK: 594 error = pledge_flock(p); 595 if (error != 0) 596 break; 597 598 if (fp->f_type != DTYPE_VNODE) { 599 error = EINVAL; 600 break; 601 } 602 vp = fp->f_data; 603 /* Copy in the lock structure */ 604 error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&fl, 605 sizeof (fl)); 606 if (error) 607 break; 608 if (fl.l_whence == SEEK_CUR) { 609 off_t offset = foffset(fp); 610 611 if (fl.l_start == 0 && fl.l_len < 0) { 612 /* lockf(3) compliance hack */ 613 fl.l_len = -fl.l_len; 614 fl.l_start = offset - fl.l_len; 615 } else 616 fl.l_start += offset; 617 } 618 if (fl.l_type != F_RDLCK && 619 fl.l_type != F_WRLCK && 620 fl.l_type != F_UNLCK && 621 fl.l_type != 0) { 622 error = EINVAL; 623 break; 624 } 625 error = VOP_ADVLOCK(vp, fdp, F_GETLK, &fl, F_POSIX); 626 if (error) 627 break; 628 #ifdef KTRACE 629 if (KTRPOINT(p, KTR_STRUCT)) 630 ktrflock(p, &fl); 631 #endif 632 error = (copyout((caddr_t)&fl, (caddr_t)SCARG(uap, arg), 633 sizeof (fl))); 634 break; 635 636 default: 637 error = EINVAL; 638 break; 639 } 640 out: 641 FRELE(fp, p); 642 return (error); 643 } 644 645 /* 646 * Common code for dup, dup2, and fcntl(F_DUPFD). 647 */ 648 int 649 finishdup(struct proc *p, struct file *fp, int old, int new, 650 register_t *retval, int dupflags) 651 { 652 struct file *oldfp; 653 struct filedesc *fdp = p->p_fd; 654 int error; 655 656 fdpassertlocked(fdp); 657 KASSERT(fp->f_iflags & FIF_INSERTED); 658 659 if (fp->f_count >= FDUP_MAX_COUNT) { 660 error = EDEADLK; 661 goto fail; 662 } 663 664 oldfp = fd_getfile(fdp, new); 665 if ((dupflags & DUPF_DUP2) && oldfp == NULL) { 666 if (fd_inuse(fdp, new)) { 667 error = EBUSY; 668 goto fail; 669 } 670 fd_used(fdp, new); 671 } 672 673 /* 674 * Use `fd_fplock' to synchronize with fd_getfile() so that 675 * the function no longer creates a new reference to the old file. 676 */ 677 mtx_enter(&fdp->fd_fplock); 678 fdp->fd_ofiles[new] = fp; 679 mtx_leave(&fdp->fd_fplock); 680 681 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] & ~UF_EXCLOSE; 682 if (dupflags & DUPF_CLOEXEC) 683 fdp->fd_ofileflags[new] |= UF_EXCLOSE; 684 *retval = new; 685 686 if (oldfp != NULL) { 687 knote_fdclose(p, new); 688 fdpunlock(fdp); 689 closef(oldfp, p); 690 } else { 691 fdpunlock(fdp); 692 } 693 694 return (0); 695 696 fail: 697 fdpunlock(fdp); 698 FRELE(fp, p); 699 return (error); 700 } 701 702 void 703 fdinsert(struct filedesc *fdp, int fd, int flags, struct file *fp) 704 { 705 struct file *fq; 706 707 fdpassertlocked(fdp); 708 709 mtx_enter(&fhdlk); 710 if ((fp->f_iflags & FIF_INSERTED) == 0) { 711 atomic_setbits_int(&fp->f_iflags, FIF_INSERTED); 712 if ((fq = fdp->fd_ofiles[0]) != NULL) { 713 LIST_INSERT_AFTER(fq, fp, f_list); 714 } else { 715 LIST_INSERT_HEAD(&filehead, fp, f_list); 716 } 717 } 718 mtx_leave(&fhdlk); 719 720 mtx_enter(&fdp->fd_fplock); 721 KASSERT(fdp->fd_ofiles[fd] == NULL); 722 fdp->fd_ofiles[fd] = fp; 723 mtx_leave(&fdp->fd_fplock); 724 725 fdp->fd_ofileflags[fd] |= (flags & UF_EXCLOSE); 726 } 727 728 void 729 fdremove(struct filedesc *fdp, int fd) 730 { 731 fdpassertlocked(fdp); 732 733 /* 734 * Use `fd_fplock' to synchronize with fd_getfile() so that 735 * the function no longer creates a new reference to the file. 736 */ 737 mtx_enter(&fdp->fd_fplock); 738 fdp->fd_ofiles[fd] = NULL; 739 mtx_leave(&fdp->fd_fplock); 740 741 fdp->fd_ofileflags[fd] = 0; 742 743 fd_unused(fdp, fd); 744 } 745 746 int 747 fdrelease(struct proc *p, int fd) 748 { 749 struct filedesc *fdp = p->p_fd; 750 struct file *fp; 751 752 fdpassertlocked(fdp); 753 754 fp = fd_getfile(fdp, fd); 755 if (fp == NULL) { 756 fdpunlock(fdp); 757 return (EBADF); 758 } 759 fdremove(fdp, fd); 760 knote_fdclose(p, fd); 761 fdpunlock(fdp); 762 return (closef(fp, p)); 763 } 764 765 /* 766 * Close a file descriptor. 767 */ 768 int 769 sys_close(struct proc *p, void *v, register_t *retval) 770 { 771 struct sys_close_args /* { 772 syscallarg(int) fd; 773 } */ *uap = v; 774 int fd = SCARG(uap, fd), error; 775 struct filedesc *fdp = p->p_fd; 776 777 fdplock(fdp); 778 /* fdrelease unlocks fdp. */ 779 error = fdrelease(p, fd); 780 781 return (error); 782 } 783 784 /* 785 * Return status information about a file descriptor. 786 */ 787 int 788 sys_fstat(struct proc *p, void *v, register_t *retval) 789 { 790 struct sys_fstat_args /* { 791 syscallarg(int) fd; 792 syscallarg(struct stat *) sb; 793 } */ *uap = v; 794 int fd = SCARG(uap, fd); 795 struct filedesc *fdp = p->p_fd; 796 struct file *fp; 797 struct stat ub; 798 int error; 799 800 if ((fp = fd_getfile(fdp, fd)) == NULL) 801 return (EBADF); 802 error = (*fp->f_ops->fo_stat)(fp, &ub, p); 803 FRELE(fp, p); 804 if (error == 0) { 805 /* 806 * Don't let non-root see generation numbers 807 * (for NFS security) 808 */ 809 if (suser(p)) 810 ub.st_gen = 0; 811 error = copyout((caddr_t)&ub, (caddr_t)SCARG(uap, sb), 812 sizeof (ub)); 813 } 814 #ifdef KTRACE 815 if (error == 0 && KTRPOINT(p, KTR_STRUCT)) 816 ktrstat(p, &ub); 817 #endif 818 return (error); 819 } 820 821 /* 822 * Return pathconf information about a file descriptor. 823 */ 824 int 825 sys_fpathconf(struct proc *p, void *v, register_t *retval) 826 { 827 struct sys_fpathconf_args /* { 828 syscallarg(int) fd; 829 syscallarg(int) name; 830 } */ *uap = v; 831 int fd = SCARG(uap, fd); 832 struct filedesc *fdp = p->p_fd; 833 struct file *fp; 834 struct vnode *vp; 835 int error; 836 837 if ((fp = fd_getfile(fdp, fd)) == NULL) 838 return (EBADF); 839 switch (fp->f_type) { 840 case DTYPE_PIPE: 841 case DTYPE_SOCKET: 842 if (SCARG(uap, name) != _PC_PIPE_BUF) { 843 error = EINVAL; 844 break; 845 } 846 *retval = PIPE_BUF; 847 error = 0; 848 break; 849 850 case DTYPE_VNODE: 851 vp = fp->f_data; 852 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 853 error = VOP_PATHCONF(vp, SCARG(uap, name), retval); 854 VOP_UNLOCK(vp); 855 break; 856 857 default: 858 error = EOPNOTSUPP; 859 break; 860 } 861 FRELE(fp, p); 862 return (error); 863 } 864 865 /* 866 * Allocate a file descriptor for the process. 867 */ 868 int 869 fdalloc(struct proc *p, int want, int *result) 870 { 871 struct filedesc *fdp = p->p_fd; 872 int lim, last, i; 873 u_int new, off; 874 875 fdpassertlocked(fdp); 876 877 /* 878 * Search for a free descriptor starting at the higher 879 * of want or fd_freefile. If that fails, consider 880 * expanding the ofile array. 881 */ 882 restart: 883 lim = min((int)lim_cur(RLIMIT_NOFILE), maxfiles); 884 last = min(fdp->fd_nfiles, lim); 885 if ((i = want) < fdp->fd_freefile) 886 i = fdp->fd_freefile; 887 off = i >> NDENTRYSHIFT; 888 new = find_next_zero(fdp->fd_himap, off, 889 (last + NDENTRIES - 1) >> NDENTRYSHIFT); 890 if (new != -1) { 891 i = find_next_zero(&fdp->fd_lomap[new], 892 new > off ? 0 : i & NDENTRYMASK, 893 NDENTRIES); 894 if (i == -1) { 895 /* 896 * Free file descriptor in this block was 897 * below want, try again with higher want. 898 */ 899 want = (new + 1) << NDENTRYSHIFT; 900 goto restart; 901 } 902 i += (new << NDENTRYSHIFT); 903 if (i < last) { 904 fd_used(fdp, i); 905 if (want <= fdp->fd_freefile) 906 fdp->fd_freefile = i; 907 *result = i; 908 fdp->fd_ofileflags[i] = 0; 909 if (ISSET(p->p_p->ps_flags, PS_PLEDGE)) 910 fdp->fd_ofileflags[i] |= UF_PLEDGED; 911 return (0); 912 } 913 } 914 if (fdp->fd_nfiles >= lim) 915 return (EMFILE); 916 917 return (ENOSPC); 918 } 919 920 void 921 fdexpand(struct proc *p) 922 { 923 struct filedesc *fdp = p->p_fd; 924 int nfiles, oldnfiles; 925 size_t copylen; 926 struct file **newofile, **oldofile; 927 char *newofileflags; 928 u_int *newhimap, *newlomap; 929 930 fdpassertlocked(fdp); 931 932 oldnfiles = fdp->fd_nfiles; 933 oldofile = fdp->fd_ofiles; 934 935 /* 936 * No space in current array. 937 */ 938 if (fdp->fd_nfiles < NDEXTENT) 939 nfiles = NDEXTENT; 940 else 941 nfiles = 2 * fdp->fd_nfiles; 942 943 newofile = mallocarray(nfiles, OFILESIZE, M_FILEDESC, M_WAITOK); 944 /* 945 * Allocate all required chunks before calling free(9) to make 946 * sure that ``fd_ofiles'' stays valid if we go to sleep. 947 */ 948 if (NDHISLOTS(nfiles) > NDHISLOTS(fdp->fd_nfiles)) { 949 newhimap = mallocarray(NDHISLOTS(nfiles), sizeof(u_int), 950 M_FILEDESC, M_WAITOK); 951 newlomap = mallocarray(NDLOSLOTS(nfiles), sizeof(u_int), 952 M_FILEDESC, M_WAITOK); 953 } 954 newofileflags = (char *) &newofile[nfiles]; 955 956 /* 957 * Copy the existing ofile and ofileflags arrays 958 * and zero the new portion of each array. 959 */ 960 copylen = sizeof(struct file *) * fdp->fd_nfiles; 961 memcpy(newofile, fdp->fd_ofiles, copylen); 962 memset((char *)newofile + copylen, 0, 963 nfiles * sizeof(struct file *) - copylen); 964 copylen = sizeof(char) * fdp->fd_nfiles; 965 memcpy(newofileflags, fdp->fd_ofileflags, copylen); 966 memset(newofileflags + copylen, 0, nfiles * sizeof(char) - copylen); 967 968 if (NDHISLOTS(nfiles) > NDHISLOTS(fdp->fd_nfiles)) { 969 copylen = NDHISLOTS(fdp->fd_nfiles) * sizeof(u_int); 970 memcpy(newhimap, fdp->fd_himap, copylen); 971 memset((char *)newhimap + copylen, 0, 972 NDHISLOTS(nfiles) * sizeof(u_int) - copylen); 973 974 copylen = NDLOSLOTS(fdp->fd_nfiles) * sizeof(u_int); 975 memcpy(newlomap, fdp->fd_lomap, copylen); 976 memset((char *)newlomap + copylen, 0, 977 NDLOSLOTS(nfiles) * sizeof(u_int) - copylen); 978 979 if (NDHISLOTS(fdp->fd_nfiles) > NDHISLOTS(NDFILE)) { 980 free(fdp->fd_himap, M_FILEDESC, 981 NDHISLOTS(fdp->fd_nfiles) * sizeof(u_int)); 982 free(fdp->fd_lomap, M_FILEDESC, 983 NDLOSLOTS(fdp->fd_nfiles) * sizeof(u_int)); 984 } 985 fdp->fd_himap = newhimap; 986 fdp->fd_lomap = newlomap; 987 } 988 989 mtx_enter(&fdp->fd_fplock); 990 fdp->fd_ofiles = newofile; 991 mtx_leave(&fdp->fd_fplock); 992 993 fdp->fd_ofileflags = newofileflags; 994 fdp->fd_nfiles = nfiles; 995 996 if (oldnfiles > NDFILE) 997 free(oldofile, M_FILEDESC, oldnfiles * OFILESIZE); 998 } 999 1000 /* 1001 * Create a new open file structure and allocate 1002 * a file descriptor for the process that refers to it. 1003 */ 1004 int 1005 falloc(struct proc *p, struct file **resultfp, int *resultfd) 1006 { 1007 struct file *fp; 1008 int error, i; 1009 1010 KASSERT(resultfp != NULL); 1011 KASSERT(resultfd != NULL); 1012 1013 fdpassertlocked(p->p_fd); 1014 restart: 1015 if ((error = fdalloc(p, 0, &i)) != 0) { 1016 if (error == ENOSPC) { 1017 fdexpand(p); 1018 goto restart; 1019 } 1020 return (error); 1021 } 1022 1023 fp = fnew(p); 1024 if (fp == NULL) { 1025 fd_unused(p->p_fd, i); 1026 return (ENFILE); 1027 } 1028 1029 FREF(fp); 1030 *resultfp = fp; 1031 *resultfd = i; 1032 1033 return (0); 1034 } 1035 1036 struct file * 1037 fnew(struct proc *p) 1038 { 1039 struct file *fp; 1040 int nfiles; 1041 1042 nfiles = atomic_inc_int_nv(&numfiles); 1043 if (nfiles > maxfiles) { 1044 atomic_dec_int(&numfiles); 1045 tablefull("file"); 1046 return (NULL); 1047 } 1048 1049 fp = pool_get(&file_pool, PR_WAITOK|PR_ZERO); 1050 /* 1051 * We need to block interrupts as long as `f_mtx' is being taken 1052 * with and without the KERNEL_LOCK(). 1053 */ 1054 mtx_init(&fp->f_mtx, IPL_MPFLOOR); 1055 fp->f_count = 1; 1056 fp->f_cred = p->p_ucred; 1057 crhold(fp->f_cred); 1058 1059 return (fp); 1060 } 1061 1062 /* 1063 * Build a new filedesc structure. 1064 */ 1065 struct filedesc * 1066 fdinit(void) 1067 { 1068 struct filedesc0 *newfdp; 1069 1070 newfdp = pool_get(&fdesc_pool, PR_WAITOK|PR_ZERO); 1071 rw_init(&newfdp->fd_fd.fd_lock, "fdlock"); 1072 mtx_init(&newfdp->fd_fd.fd_fplock, IPL_MPFLOOR); 1073 LIST_INIT(&newfdp->fd_fd.fd_kqlist); 1074 1075 /* Create the file descriptor table. */ 1076 newfdp->fd_fd.fd_refcnt = 1; 1077 newfdp->fd_fd.fd_cmask = S_IWGRP|S_IWOTH; 1078 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1079 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1080 newfdp->fd_fd.fd_nfiles = NDFILE; 1081 newfdp->fd_fd.fd_himap = newfdp->fd_dhimap; 1082 newfdp->fd_fd.fd_lomap = newfdp->fd_dlomap; 1083 1084 newfdp->fd_fd.fd_freefile = 0; 1085 newfdp->fd_fd.fd_lastfile = 0; 1086 1087 return (&newfdp->fd_fd); 1088 } 1089 1090 /* 1091 * Share a filedesc structure. 1092 */ 1093 struct filedesc * 1094 fdshare(struct process *pr) 1095 { 1096 pr->ps_fd->fd_refcnt++; 1097 return (pr->ps_fd); 1098 } 1099 1100 /* 1101 * Copy a filedesc structure. 1102 */ 1103 struct filedesc * 1104 fdcopy(struct process *pr) 1105 { 1106 struct filedesc *newfdp, *fdp = pr->ps_fd; 1107 int i; 1108 1109 newfdp = fdinit(); 1110 1111 fdplock(fdp); 1112 if (fdp->fd_cdir) { 1113 vref(fdp->fd_cdir); 1114 newfdp->fd_cdir = fdp->fd_cdir; 1115 } 1116 if (fdp->fd_rdir) { 1117 vref(fdp->fd_rdir); 1118 newfdp->fd_rdir = fdp->fd_rdir; 1119 } 1120 1121 /* 1122 * If the number of open files fits in the internal arrays 1123 * of the open file structure, use them, otherwise allocate 1124 * additional memory for the number of descriptors currently 1125 * in use. 1126 */ 1127 if (fdp->fd_lastfile >= NDFILE) { 1128 /* 1129 * Compute the smallest multiple of NDEXTENT needed 1130 * for the file descriptors currently in use, 1131 * allowing the table to shrink. 1132 */ 1133 i = fdp->fd_nfiles; 1134 while (i >= 2 * NDEXTENT && i > fdp->fd_lastfile * 2) 1135 i /= 2; 1136 newfdp->fd_ofiles = mallocarray(i, OFILESIZE, M_FILEDESC, 1137 M_WAITOK | M_ZERO); 1138 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 1139 newfdp->fd_nfiles = i; 1140 } 1141 if (NDHISLOTS(newfdp->fd_nfiles) > NDHISLOTS(NDFILE)) { 1142 newfdp->fd_himap = mallocarray(NDHISLOTS(newfdp->fd_nfiles), 1143 sizeof(u_int), M_FILEDESC, M_WAITOK | M_ZERO); 1144 newfdp->fd_lomap = mallocarray(NDLOSLOTS(newfdp->fd_nfiles), 1145 sizeof(u_int), M_FILEDESC, M_WAITOK | M_ZERO); 1146 } 1147 newfdp->fd_freefile = fdp->fd_freefile; 1148 newfdp->fd_flags = fdp->fd_flags; 1149 newfdp->fd_cmask = fdp->fd_cmask; 1150 1151 for (i = 0; i <= fdp->fd_lastfile; i++) { 1152 struct file *fp = fdp->fd_ofiles[i]; 1153 1154 if (fp != NULL) { 1155 /* 1156 * XXX Gruesome hack. If count gets too high, fail 1157 * to copy an fd, since fdcopy()'s callers do not 1158 * permit it to indicate failure yet. 1159 * Meanwhile, kqueue files have to be 1160 * tied to the process that opened them to enforce 1161 * their internal consistency, so close them here. 1162 */ 1163 if (fp->f_count >= FDUP_MAX_COUNT || 1164 fp->f_type == DTYPE_KQUEUE) { 1165 if (i < newfdp->fd_freefile) 1166 newfdp->fd_freefile = i; 1167 continue; 1168 } 1169 1170 FREF(fp); 1171 newfdp->fd_ofiles[i] = fp; 1172 newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i]; 1173 fd_used(newfdp, i); 1174 } 1175 } 1176 fdpunlock(fdp); 1177 1178 return (newfdp); 1179 } 1180 1181 /* 1182 * Release a filedesc structure. 1183 */ 1184 void 1185 fdfree(struct proc *p) 1186 { 1187 struct filedesc *fdp = p->p_fd; 1188 struct file *fp; 1189 int fd; 1190 1191 if (--fdp->fd_refcnt > 0) 1192 return; 1193 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 1194 fp = fdp->fd_ofiles[fd]; 1195 if (fp != NULL) { 1196 fdp->fd_ofiles[fd] = NULL; 1197 knote_fdclose(p, fd); 1198 /* closef() expects a refcount of 2 */ 1199 FREF(fp); 1200 (void) closef(fp, p); 1201 } 1202 } 1203 p->p_fd = NULL; 1204 if (fdp->fd_nfiles > NDFILE) 1205 free(fdp->fd_ofiles, M_FILEDESC, fdp->fd_nfiles * OFILESIZE); 1206 if (NDHISLOTS(fdp->fd_nfiles) > NDHISLOTS(NDFILE)) { 1207 free(fdp->fd_himap, M_FILEDESC, 1208 NDHISLOTS(fdp->fd_nfiles) * sizeof(u_int)); 1209 free(fdp->fd_lomap, M_FILEDESC, 1210 NDLOSLOTS(fdp->fd_nfiles) * sizeof(u_int)); 1211 } 1212 if (fdp->fd_cdir) 1213 vrele(fdp->fd_cdir); 1214 if (fdp->fd_rdir) 1215 vrele(fdp->fd_rdir); 1216 pool_put(&fdesc_pool, fdp); 1217 } 1218 1219 /* 1220 * Internal form of close. 1221 * Decrement reference count on file structure. 1222 * Note: p may be NULL when closing a file 1223 * that was being passed in a message. 1224 * 1225 * The fp must have its usecount bumped and will be FRELEd here. 1226 */ 1227 int 1228 closef(struct file *fp, struct proc *p) 1229 { 1230 struct filedesc *fdp; 1231 1232 if (fp == NULL) 1233 return (0); 1234 1235 KASSERTMSG(fp->f_count >= 2, "count (%u) < 2", fp->f_count); 1236 1237 atomic_dec_int(&fp->f_count); 1238 1239 /* 1240 * POSIX record locking dictates that any close releases ALL 1241 * locks owned by this process. This is handled by setting 1242 * a flag in the unlock to free ONLY locks obeying POSIX 1243 * semantics, and not to free BSD-style file locks. 1244 * If the descriptor was in a message, POSIX-style locks 1245 * aren't passed with the descriptor. 1246 */ 1247 1248 if (p && ((fdp = p->p_fd) != NULL) && 1249 (fdp->fd_flags & FD_ADVLOCK) && 1250 fp->f_type == DTYPE_VNODE) { 1251 struct vnode *vp = fp->f_data; 1252 struct flock lf; 1253 1254 lf.l_whence = SEEK_SET; 1255 lf.l_start = 0; 1256 lf.l_len = 0; 1257 lf.l_type = F_UNLCK; 1258 (void) VOP_ADVLOCK(vp, fdp, F_UNLCK, &lf, F_POSIX); 1259 } 1260 1261 return (FRELE(fp, p)); 1262 } 1263 1264 int 1265 fdrop(struct file *fp, struct proc *p) 1266 { 1267 int error; 1268 1269 KASSERTMSG(fp->f_count == 0, "count (%u) != 0", fp->f_count); 1270 1271 mtx_enter(&fhdlk); 1272 if (fp->f_iflags & FIF_INSERTED) 1273 LIST_REMOVE(fp, f_list); 1274 mtx_leave(&fhdlk); 1275 1276 if (fp->f_ops) 1277 error = (*fp->f_ops->fo_close)(fp, p); 1278 else 1279 error = 0; 1280 1281 crfree(fp->f_cred); 1282 atomic_dec_int(&numfiles); 1283 pool_put(&file_pool, fp); 1284 1285 return (error); 1286 } 1287 1288 /* 1289 * Apply an advisory lock on a file descriptor. 1290 * 1291 * Just attempt to get a record lock of the requested type on 1292 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 1293 */ 1294 int 1295 sys_flock(struct proc *p, void *v, register_t *retval) 1296 { 1297 struct sys_flock_args /* { 1298 syscallarg(int) fd; 1299 syscallarg(int) how; 1300 } */ *uap = v; 1301 int fd = SCARG(uap, fd); 1302 int how = SCARG(uap, how); 1303 struct filedesc *fdp = p->p_fd; 1304 struct file *fp; 1305 struct vnode *vp; 1306 struct flock lf; 1307 int error; 1308 1309 if ((fp = fd_getfile(fdp, fd)) == NULL) 1310 return (EBADF); 1311 if (fp->f_type != DTYPE_VNODE) { 1312 error = EOPNOTSUPP; 1313 goto out; 1314 } 1315 vp = fp->f_data; 1316 lf.l_whence = SEEK_SET; 1317 lf.l_start = 0; 1318 lf.l_len = 0; 1319 if (how & LOCK_UN) { 1320 lf.l_type = F_UNLCK; 1321 atomic_clearbits_int(&fp->f_iflags, FIF_HASLOCK); 1322 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 1323 goto out; 1324 } 1325 if (how & LOCK_EX) 1326 lf.l_type = F_WRLCK; 1327 else if (how & LOCK_SH) 1328 lf.l_type = F_RDLCK; 1329 else { 1330 error = EINVAL; 1331 goto out; 1332 } 1333 atomic_setbits_int(&fp->f_iflags, FIF_HASLOCK); 1334 if (how & LOCK_NB) 1335 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK); 1336 else 1337 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT); 1338 out: 1339 FRELE(fp, p); 1340 return (error); 1341 } 1342 1343 /* 1344 * File Descriptor pseudo-device driver (/dev/fd/). 1345 * 1346 * Opening minor device N dup()s the file (if any) connected to file 1347 * descriptor N belonging to the calling process. Note that this driver 1348 * consists of only the ``open()'' routine, because all subsequent 1349 * references to this file will be direct to the other driver. 1350 */ 1351 int 1352 filedescopen(dev_t dev, int mode, int type, struct proc *p) 1353 { 1354 1355 /* 1356 * XXX Kludge: set curproc->p_dupfd to contain the value of the 1357 * the file descriptor being sought for duplication. The error 1358 * return ensures that the vnode for this device will be released 1359 * by vn_open. Open will detect this special error and take the 1360 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 1361 * will simply report the error. 1362 */ 1363 p->p_dupfd = minor(dev); 1364 return (ENODEV); 1365 } 1366 1367 /* 1368 * Duplicate the specified descriptor to a free descriptor. 1369 */ 1370 int 1371 dupfdopen(struct proc *p, int indx, int mode) 1372 { 1373 struct filedesc *fdp = p->p_fd; 1374 int dupfd = p->p_dupfd; 1375 struct file *wfp; 1376 1377 fdpassertlocked(fdp); 1378 1379 /* 1380 * Assume that the filename was user-specified; applications do 1381 * not tend to open /dev/fd/# when they can just call dup() 1382 */ 1383 if ((p->p_p->ps_flags & (PS_SUGIDEXEC | PS_SUGID))) { 1384 if (p->p_descfd == 255) 1385 return (EPERM); 1386 if (p->p_descfd != dupfd) 1387 return (EPERM); 1388 } 1389 1390 /* 1391 * If the to-be-dup'd fd number is greater than the allowed number 1392 * of file descriptors, or the fd to be dup'd has already been 1393 * closed, reject. Note, there is no need to check for new == old 1394 * because fd_getfile will return NULL if the file at indx is 1395 * newly created by falloc. 1396 */ 1397 if ((wfp = fd_getfile(fdp, dupfd)) == NULL) 1398 return (EBADF); 1399 1400 /* 1401 * Check that the mode the file is being opened for is a 1402 * subset of the mode of the existing descriptor. 1403 */ 1404 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 1405 FRELE(wfp, p); 1406 return (EACCES); 1407 } 1408 if (wfp->f_count >= FDUP_MAX_COUNT) { 1409 FRELE(wfp, p); 1410 return (EDEADLK); 1411 } 1412 1413 KASSERT(wfp->f_iflags & FIF_INSERTED); 1414 1415 mtx_enter(&fdp->fd_fplock); 1416 KASSERT(fdp->fd_ofiles[indx] == NULL); 1417 fdp->fd_ofiles[indx] = wfp; 1418 mtx_leave(&fdp->fd_fplock); 1419 1420 fdp->fd_ofileflags[indx] = (fdp->fd_ofileflags[indx] & UF_EXCLOSE) | 1421 (fdp->fd_ofileflags[dupfd] & ~UF_EXCLOSE); 1422 1423 return (0); 1424 } 1425 1426 /* 1427 * Close any files on exec? 1428 */ 1429 void 1430 fdcloseexec(struct proc *p) 1431 { 1432 struct filedesc *fdp = p->p_fd; 1433 int fd; 1434 1435 fdplock(fdp); 1436 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 1437 fdp->fd_ofileflags[fd] &= ~UF_PLEDGED; 1438 if (fdp->fd_ofileflags[fd] & UF_EXCLOSE) { 1439 /* fdrelease() unlocks fdp. */ 1440 (void) fdrelease(p, fd); 1441 fdplock(fdp); 1442 } 1443 } 1444 fdpunlock(fdp); 1445 } 1446 1447 int 1448 sys_closefrom(struct proc *p, void *v, register_t *retval) 1449 { 1450 struct sys_closefrom_args *uap = v; 1451 struct filedesc *fdp = p->p_fd; 1452 u_int startfd, i; 1453 1454 startfd = SCARG(uap, fd); 1455 fdplock(fdp); 1456 1457 if (startfd > fdp->fd_lastfile) { 1458 fdpunlock(fdp); 1459 return (EBADF); 1460 } 1461 1462 for (i = startfd; i <= fdp->fd_lastfile; i++) { 1463 /* fdrelease() unlocks fdp. */ 1464 fdrelease(p, i); 1465 fdplock(fdp); 1466 } 1467 1468 fdpunlock(fdp); 1469 return (0); 1470 } 1471 1472 int 1473 sys_getdtablecount(struct proc *p, void *v, register_t *retval) 1474 { 1475 *retval = p->p_fd->fd_openfd; 1476 return (0); 1477 } 1478