1/*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 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 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: stable/11/sys/kern/kern_descrip.c 369335 2021-02-22 19:08:27Z jamie $"); 39 40#include "opt_capsicum.h" 41#include "opt_compat.h" 42#include "opt_ddb.h" 43#include "opt_ktrace.h" 44 45#include <sys/param.h> 46#include <sys/systm.h> 47 48#include <sys/capsicum.h> 49#include <sys/conf.h> 50#include <sys/fcntl.h> 51#include <sys/file.h> 52#include <sys/filedesc.h> 53#include <sys/filio.h> 54#include <sys/jail.h> 55#include <sys/kernel.h> 56#include <sys/limits.h> 57#include <sys/lock.h> 58#include <sys/malloc.h> 59#include <sys/mount.h> 60#include <sys/mutex.h> 61#include <sys/namei.h> 62#include <sys/selinfo.h> 63#include <sys/priv.h> 64#include <sys/proc.h> 65#include <sys/protosw.h> 66#include <sys/racct.h> 67#include <sys/resourcevar.h> 68#include <sys/sbuf.h> 69#include <sys/signalvar.h> 70#include <sys/kdb.h> 71#include <sys/stat.h> 72#include <sys/sx.h> 73#include <sys/syscallsubr.h> 74#include <sys/sysctl.h> 75#include <sys/sysproto.h> 76#include <sys/unistd.h> 77#include <sys/user.h> 78#include <sys/vnode.h> 79#ifdef KTRACE 80#include <sys/ktrace.h> 81#endif 82 83#include <net/vnet.h> 84 85#include <security/audit/audit.h> 86 87#include <vm/uma.h> 88#include <vm/vm.h> 89 90#include <ddb/ddb.h> 91 92static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 93static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 94 "file desc to leader structures"); 95static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 96MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 97 98MALLOC_DECLARE(M_FADVISE); 99 100static __read_mostly uma_zone_t file_zone; 101static __read_mostly uma_zone_t filedesc0_zone; 102 103static int closefp(struct filedesc *fdp, int fd, struct file *fp, 104 struct thread *td, int holdleaders); 105static int fd_first_free(struct filedesc *fdp, int low, int size); 106static int fd_last_used(struct filedesc *fdp, int size); 107static void fdgrowtable(struct filedesc *fdp, int nfd); 108static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 109static void fdunused(struct filedesc *fdp, int fd); 110static void fdused(struct filedesc *fdp, int fd); 111static int getmaxfd(struct thread *td); 112 113/* 114 * Each process has: 115 * 116 * - An array of open file descriptors (fd_ofiles) 117 * - An array of file flags (fd_ofileflags) 118 * - A bitmap recording which descriptors are in use (fd_map) 119 * 120 * A process starts out with NDFILE descriptors. The value of NDFILE has 121 * been selected based the historical limit of 20 open files, and an 122 * assumption that the majority of processes, especially short-lived 123 * processes like shells, will never need more. 124 * 125 * If this initial allocation is exhausted, a larger descriptor table and 126 * map are allocated dynamically, and the pointers in the process's struct 127 * filedesc are updated to point to those. This is repeated every time 128 * the process runs out of file descriptors (provided it hasn't hit its 129 * resource limit). 130 * 131 * Since threads may hold references to individual descriptor table 132 * entries, the tables are never freed. Instead, they are placed on a 133 * linked list and freed only when the struct filedesc is released. 134 */ 135#define NDFILE 20 136#define NDSLOTSIZE sizeof(NDSLOTTYPE) 137#define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 138#define NDSLOT(x) ((x) / NDENTRIES) 139#define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 140#define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 141 142/* 143 * SLIST entry used to keep track of ofiles which must be reclaimed when 144 * the process exits. 145 */ 146struct freetable { 147 struct fdescenttbl *ft_table; 148 SLIST_ENTRY(freetable) ft_next; 149}; 150 151/* 152 * Initial allocation: a filedesc structure + the head of SLIST used to 153 * keep track of old ofiles + enough space for NDFILE descriptors. 154 */ 155 156struct fdescenttbl0 { 157 int fdt_nfiles; 158 struct filedescent fdt_ofiles[NDFILE]; 159}; 160 161struct filedesc0 { 162 struct filedesc fd_fd; 163 SLIST_HEAD(, freetable) fd_free; 164 struct fdescenttbl0 fd_dfiles; 165 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 166}; 167 168/* 169 * Descriptor management. 170 */ 171volatile int __exclusive_cache_line openfiles; /* actual number of open files */ 172struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 173void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 174 175/* 176 * If low >= size, just return low. Otherwise find the first zero bit in the 177 * given bitmap, starting at low and not exceeding size - 1. Return size if 178 * not found. 179 */ 180static int 181fd_first_free(struct filedesc *fdp, int low, int size) 182{ 183 NDSLOTTYPE *map = fdp->fd_map; 184 NDSLOTTYPE mask; 185 int off, maxoff; 186 187 if (low >= size) 188 return (low); 189 190 off = NDSLOT(low); 191 if (low % NDENTRIES) { 192 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 193 if ((mask &= ~map[off]) != 0UL) 194 return (off * NDENTRIES + ffsl(mask) - 1); 195 ++off; 196 } 197 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 198 if (map[off] != ~0UL) 199 return (off * NDENTRIES + ffsl(~map[off]) - 1); 200 return (size); 201} 202 203/* 204 * Find the highest non-zero bit in the given bitmap, starting at 0 and 205 * not exceeding size - 1. Return -1 if not found. 206 */ 207static int 208fd_last_used(struct filedesc *fdp, int size) 209{ 210 NDSLOTTYPE *map = fdp->fd_map; 211 NDSLOTTYPE mask; 212 int off, minoff; 213 214 off = NDSLOT(size); 215 if (size % NDENTRIES) { 216 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 217 if ((mask &= map[off]) != 0) 218 return (off * NDENTRIES + flsl(mask) - 1); 219 --off; 220 } 221 for (minoff = NDSLOT(0); off >= minoff; --off) 222 if (map[off] != 0) 223 return (off * NDENTRIES + flsl(map[off]) - 1); 224 return (-1); 225} 226 227static int 228fdisused(struct filedesc *fdp, int fd) 229{ 230 231 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 232 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 233 234 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 235} 236 237/* 238 * Mark a file descriptor as used. 239 */ 240static void 241fdused_init(struct filedesc *fdp, int fd) 242{ 243 244 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 245 246 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 247} 248 249static void 250fdused(struct filedesc *fdp, int fd) 251{ 252 253 FILEDESC_XLOCK_ASSERT(fdp); 254 255 fdused_init(fdp, fd); 256 if (fd > fdp->fd_lastfile) 257 fdp->fd_lastfile = fd; 258 if (fd == fdp->fd_freefile) 259 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 260} 261 262/* 263 * Mark a file descriptor as unused. 264 */ 265static void 266fdunused(struct filedesc *fdp, int fd) 267{ 268 269 FILEDESC_XLOCK_ASSERT(fdp); 270 271 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 272 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 273 ("fd=%d is still in use", fd)); 274 275 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 276 if (fd < fdp->fd_freefile) 277 fdp->fd_freefile = fd; 278 if (fd == fdp->fd_lastfile) 279 fdp->fd_lastfile = fd_last_used(fdp, fd); 280} 281 282/* 283 * Free a file descriptor. 284 * 285 * Avoid some work if fdp is about to be destroyed. 286 */ 287static inline void 288fdefree_last(struct filedescent *fde) 289{ 290 291 filecaps_free(&fde->fde_caps); 292} 293 294static inline void 295fdfree(struct filedesc *fdp, int fd) 296{ 297 struct filedescent *fde; 298 299 fde = &fdp->fd_ofiles[fd]; 300#ifdef CAPABILITIES 301 seq_write_begin(&fde->fde_seq); 302#endif 303 fdefree_last(fde); 304 fde->fde_file = NULL; 305 fdunused(fdp, fd); 306#ifdef CAPABILITIES 307 seq_write_end(&fde->fde_seq); 308#endif 309} 310 311void 312pwd_ensure_dirs(void) 313{ 314 struct filedesc *fdp; 315 316 fdp = curproc->p_fd; 317 FILEDESC_XLOCK(fdp); 318 if (fdp->fd_cdir == NULL) { 319 fdp->fd_cdir = rootvnode; 320 vrefact(rootvnode); 321 } 322 if (fdp->fd_rdir == NULL) { 323 fdp->fd_rdir = rootvnode; 324 vrefact(rootvnode); 325 } 326 FILEDESC_XUNLOCK(fdp); 327} 328 329/* 330 * System calls on descriptors. 331 */ 332#ifndef _SYS_SYSPROTO_H_ 333struct getdtablesize_args { 334 int dummy; 335}; 336#endif 337/* ARGSUSED */ 338int 339sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 340{ 341#ifdef RACCT 342 uint64_t lim; 343#endif 344 345 td->td_retval[0] = 346 min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc); 347#ifdef RACCT 348 PROC_LOCK(td->td_proc); 349 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 350 PROC_UNLOCK(td->td_proc); 351 if (lim < td->td_retval[0]) 352 td->td_retval[0] = lim; 353#endif 354 return (0); 355} 356 357/* 358 * Duplicate a file descriptor to a particular value. 359 * 360 * Note: keep in mind that a potential race condition exists when closing 361 * descriptors from a shared descriptor table (via rfork). 362 */ 363#ifndef _SYS_SYSPROTO_H_ 364struct dup2_args { 365 u_int from; 366 u_int to; 367}; 368#endif 369/* ARGSUSED */ 370int 371sys_dup2(struct thread *td, struct dup2_args *uap) 372{ 373 374 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 375} 376 377/* 378 * Duplicate a file descriptor. 379 */ 380#ifndef _SYS_SYSPROTO_H_ 381struct dup_args { 382 u_int fd; 383}; 384#endif 385/* ARGSUSED */ 386int 387sys_dup(struct thread *td, struct dup_args *uap) 388{ 389 390 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 391} 392 393/* 394 * The file control system call. 395 */ 396#ifndef _SYS_SYSPROTO_H_ 397struct fcntl_args { 398 int fd; 399 int cmd; 400 long arg; 401}; 402#endif 403/* ARGSUSED */ 404int 405sys_fcntl(struct thread *td, struct fcntl_args *uap) 406{ 407 408 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 409} 410 411int 412kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 413{ 414 struct flock fl; 415 struct __oflock ofl; 416 intptr_t arg1; 417 int error, newcmd; 418 419 error = 0; 420 newcmd = cmd; 421 switch (cmd) { 422 case F_OGETLK: 423 case F_OSETLK: 424 case F_OSETLKW: 425 /* 426 * Convert old flock structure to new. 427 */ 428 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 429 fl.l_start = ofl.l_start; 430 fl.l_len = ofl.l_len; 431 fl.l_pid = ofl.l_pid; 432 fl.l_type = ofl.l_type; 433 fl.l_whence = ofl.l_whence; 434 fl.l_sysid = 0; 435 436 switch (cmd) { 437 case F_OGETLK: 438 newcmd = F_GETLK; 439 break; 440 case F_OSETLK: 441 newcmd = F_SETLK; 442 break; 443 case F_OSETLKW: 444 newcmd = F_SETLKW; 445 break; 446 } 447 arg1 = (intptr_t)&fl; 448 break; 449 case F_GETLK: 450 case F_SETLK: 451 case F_SETLKW: 452 case F_SETLK_REMOTE: 453 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 454 arg1 = (intptr_t)&fl; 455 break; 456 default: 457 arg1 = arg; 458 break; 459 } 460 if (error) 461 return (error); 462 error = kern_fcntl(td, fd, newcmd, arg1); 463 if (error) 464 return (error); 465 if (cmd == F_OGETLK) { 466 ofl.l_start = fl.l_start; 467 ofl.l_len = fl.l_len; 468 ofl.l_pid = fl.l_pid; 469 ofl.l_type = fl.l_type; 470 ofl.l_whence = fl.l_whence; 471 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 472 } else if (cmd == F_GETLK) { 473 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 474 } 475 return (error); 476} 477 478int 479kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 480{ 481 struct filedesc *fdp; 482 struct flock *flp; 483 struct file *fp, *fp2; 484 struct filedescent *fde; 485 struct proc *p; 486 struct vnode *vp; 487 cap_rights_t rights; 488 int error, flg, tmp; 489 uint64_t bsize; 490 off_t foffset; 491 492 error = 0; 493 flg = F_POSIX; 494 p = td->td_proc; 495 fdp = p->p_fd; 496 497 switch (cmd) { 498 case F_DUPFD: 499 tmp = arg; 500 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 501 break; 502 503 case F_DUPFD_CLOEXEC: 504 tmp = arg; 505 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 506 break; 507 508 case F_DUP2FD: 509 tmp = arg; 510 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 511 break; 512 513 case F_DUP2FD_CLOEXEC: 514 tmp = arg; 515 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 516 break; 517 518 case F_GETFD: 519 error = EBADF; 520 FILEDESC_SLOCK(fdp); 521 fde = fdeget_locked(fdp, fd); 522 if (fde != NULL) { 523 td->td_retval[0] = 524 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 525 error = 0; 526 } 527 FILEDESC_SUNLOCK(fdp); 528 break; 529 530 case F_SETFD: 531 error = EBADF; 532 FILEDESC_XLOCK(fdp); 533 fde = fdeget_locked(fdp, fd); 534 if (fde != NULL) { 535 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 536 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 537 error = 0; 538 } 539 FILEDESC_XUNLOCK(fdp); 540 break; 541 542 case F_GETFL: 543 error = fget_fcntl(td, fd, 544 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp); 545 if (error != 0) 546 break; 547 td->td_retval[0] = OFLAGS(fp->f_flag); 548 fdrop(fp, td); 549 break; 550 551 case F_SETFL: 552 error = fget_fcntl(td, fd, 553 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp); 554 if (error != 0) 555 break; 556 do { 557 tmp = flg = fp->f_flag; 558 tmp &= ~FCNTLFLAGS; 559 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 560 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 561 tmp = fp->f_flag & FNONBLOCK; 562 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 563 if (error != 0) { 564 fdrop(fp, td); 565 break; 566 } 567 tmp = fp->f_flag & FASYNC; 568 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 569 if (error == 0) { 570 fdrop(fp, td); 571 break; 572 } 573 atomic_clear_int(&fp->f_flag, FNONBLOCK); 574 tmp = 0; 575 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 576 fdrop(fp, td); 577 break; 578 579 case F_GETOWN: 580 error = fget_fcntl(td, fd, 581 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp); 582 if (error != 0) 583 break; 584 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 585 if (error == 0) 586 td->td_retval[0] = tmp; 587 fdrop(fp, td); 588 break; 589 590 case F_SETOWN: 591 error = fget_fcntl(td, fd, 592 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp); 593 if (error != 0) 594 break; 595 tmp = arg; 596 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 597 fdrop(fp, td); 598 break; 599 600 case F_SETLK_REMOTE: 601 error = priv_check(td, PRIV_NFS_LOCKD); 602 if (error) 603 return (error); 604 flg = F_REMOTE; 605 goto do_setlk; 606 607 case F_SETLKW: 608 flg |= F_WAIT; 609 /* FALLTHROUGH F_SETLK */ 610 611 case F_SETLK: 612 do_setlk: 613 cap_rights_init(&rights, CAP_FLOCK); 614 error = fget_unlocked(fdp, fd, &rights, &fp, NULL); 615 if (error != 0) 616 break; 617 if (fp->f_type != DTYPE_VNODE) { 618 error = EBADF; 619 fdrop(fp, td); 620 break; 621 } 622 623 flp = (struct flock *)arg; 624 if (flp->l_whence == SEEK_CUR) { 625 foffset = foffset_get(fp); 626 if (foffset < 0 || 627 (flp->l_start > 0 && 628 foffset > OFF_MAX - flp->l_start)) { 629 error = EOVERFLOW; 630 fdrop(fp, td); 631 break; 632 } 633 flp->l_start += foffset; 634 } 635 636 vp = fp->f_vnode; 637 switch (flp->l_type) { 638 case F_RDLCK: 639 if ((fp->f_flag & FREAD) == 0) { 640 error = EBADF; 641 break; 642 } 643 PROC_LOCK(p->p_leader); 644 p->p_leader->p_flag |= P_ADVLOCK; 645 PROC_UNLOCK(p->p_leader); 646 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 647 flp, flg); 648 break; 649 case F_WRLCK: 650 if ((fp->f_flag & FWRITE) == 0) { 651 error = EBADF; 652 break; 653 } 654 PROC_LOCK(p->p_leader); 655 p->p_leader->p_flag |= P_ADVLOCK; 656 PROC_UNLOCK(p->p_leader); 657 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 658 flp, flg); 659 break; 660 case F_UNLCK: 661 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 662 flp, flg); 663 break; 664 case F_UNLCKSYS: 665 /* 666 * Temporary api for testing remote lock 667 * infrastructure. 668 */ 669 if (flg != F_REMOTE) { 670 error = EINVAL; 671 break; 672 } 673 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 674 F_UNLCKSYS, flp, flg); 675 break; 676 default: 677 error = EINVAL; 678 break; 679 } 680 if (error != 0 || flp->l_type == F_UNLCK || 681 flp->l_type == F_UNLCKSYS) { 682 fdrop(fp, td); 683 break; 684 } 685 686 /* 687 * Check for a race with close. 688 * 689 * The vnode is now advisory locked (or unlocked, but this case 690 * is not really important) as the caller requested. 691 * We had to drop the filedesc lock, so we need to recheck if 692 * the descriptor is still valid, because if it was closed 693 * in the meantime we need to remove advisory lock from the 694 * vnode - close on any descriptor leading to an advisory 695 * locked vnode, removes that lock. 696 * We will return 0 on purpose in that case, as the result of 697 * successful advisory lock might have been externally visible 698 * already. This is fine - effectively we pretend to the caller 699 * that the closing thread was a bit slower and that the 700 * advisory lock succeeded before the close. 701 */ 702 error = fget_unlocked(fdp, fd, &rights, &fp2, NULL); 703 if (error != 0) { 704 fdrop(fp, td); 705 break; 706 } 707 if (fp != fp2) { 708 flp->l_whence = SEEK_SET; 709 flp->l_start = 0; 710 flp->l_len = 0; 711 flp->l_type = F_UNLCK; 712 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 713 F_UNLCK, flp, F_POSIX); 714 } 715 fdrop(fp, td); 716 fdrop(fp2, td); 717 break; 718 719 case F_GETLK: 720 error = fget_unlocked(fdp, fd, 721 cap_rights_init(&rights, CAP_FLOCK), &fp, NULL); 722 if (error != 0) 723 break; 724 if (fp->f_type != DTYPE_VNODE) { 725 error = EBADF; 726 fdrop(fp, td); 727 break; 728 } 729 flp = (struct flock *)arg; 730 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 731 flp->l_type != F_UNLCK) { 732 error = EINVAL; 733 fdrop(fp, td); 734 break; 735 } 736 if (flp->l_whence == SEEK_CUR) { 737 foffset = foffset_get(fp); 738 if ((flp->l_start > 0 && 739 foffset > OFF_MAX - flp->l_start) || 740 (flp->l_start < 0 && 741 foffset < OFF_MIN - flp->l_start)) { 742 error = EOVERFLOW; 743 fdrop(fp, td); 744 break; 745 } 746 flp->l_start += foffset; 747 } 748 vp = fp->f_vnode; 749 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 750 F_POSIX); 751 fdrop(fp, td); 752 break; 753 754 case F_RDAHEAD: 755 arg = arg ? 128 * 1024: 0; 756 /* FALLTHROUGH */ 757 case F_READAHEAD: 758 error = fget_unlocked(fdp, fd, 759 cap_rights_init(&rights), &fp, NULL); 760 if (error != 0) 761 break; 762 if (fp->f_type != DTYPE_VNODE) { 763 fdrop(fp, td); 764 error = EBADF; 765 break; 766 } 767 vp = fp->f_vnode; 768 if (vp->v_type != VREG) { 769 fdrop(fp, td); 770 error = ENOTTY; 771 break; 772 } 773 774 /* 775 * Exclusive lock synchronizes against f_seqcount reads and 776 * writes in sequential_heuristic(). 777 */ 778 error = vn_lock(vp, LK_EXCLUSIVE); 779 if (error != 0) { 780 fdrop(fp, td); 781 break; 782 } 783 if (arg >= 0) { 784 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 785 fp->f_seqcount = (arg + bsize - 1) / bsize; 786 atomic_set_int(&fp->f_flag, FRDAHEAD); 787 } else { 788 atomic_clear_int(&fp->f_flag, FRDAHEAD); 789 } 790 VOP_UNLOCK(vp, 0); 791 fdrop(fp, td); 792 break; 793 794 default: 795 error = EINVAL; 796 break; 797 } 798 return (error); 799} 800 801static int 802getmaxfd(struct thread *td) 803{ 804 805 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 806} 807 808/* 809 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 810 */ 811int 812kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 813{ 814 struct filedesc *fdp; 815 struct filedescent *oldfde, *newfde; 816 struct proc *p; 817 struct file *delfp; 818 int error, maxfd; 819 820 p = td->td_proc; 821 fdp = p->p_fd; 822 823 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 824 MPASS(mode < FDDUP_LASTMODE); 825 826 AUDIT_ARG_FD(old); 827 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 828 829 /* 830 * Verify we have a valid descriptor to dup from and possibly to 831 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 832 * return EINVAL when the new descriptor is out of bounds. 833 */ 834 if (old < 0) 835 return (EBADF); 836 if (new < 0) 837 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 838 maxfd = getmaxfd(td); 839 if (new >= maxfd) 840 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 841 842 error = EBADF; 843 FILEDESC_XLOCK(fdp); 844 if (fget_locked(fdp, old) == NULL) 845 goto unlock; 846 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 847 td->td_retval[0] = new; 848 if (flags & FDDUP_FLAG_CLOEXEC) 849 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 850 error = 0; 851 goto unlock; 852 } 853 854 /* 855 * If the caller specified a file descriptor, make sure the file 856 * table is large enough to hold it, and grab it. Otherwise, just 857 * allocate a new descriptor the usual way. 858 */ 859 switch (mode) { 860 case FDDUP_NORMAL: 861 case FDDUP_FCNTL: 862 if ((error = fdalloc(td, new, &new)) != 0) 863 goto unlock; 864 break; 865 case FDDUP_MUSTREPLACE: 866 /* Target file descriptor must exist. */ 867 if (fget_locked(fdp, new) == NULL) 868 goto unlock; 869 break; 870 case FDDUP_FIXED: 871 if (new >= fdp->fd_nfiles) { 872 /* 873 * The resource limits are here instead of e.g. 874 * fdalloc(), because the file descriptor table may be 875 * shared between processes, so we can't really use 876 * racct_add()/racct_sub(). Instead of counting the 877 * number of actually allocated descriptors, just put 878 * the limit on the size of the file descriptor table. 879 */ 880#ifdef RACCT 881 if (racct_enable) { 882 PROC_LOCK(p); 883 error = racct_set(p, RACCT_NOFILE, new + 1); 884 PROC_UNLOCK(p); 885 if (error != 0) { 886 error = EMFILE; 887 goto unlock; 888 } 889 } 890#endif 891 fdgrowtable_exp(fdp, new + 1); 892 } 893 if (!fdisused(fdp, new)) 894 fdused(fdp, new); 895 break; 896 default: 897 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 898 } 899 900 KASSERT(old != new, ("new fd is same as old")); 901 902 oldfde = &fdp->fd_ofiles[old]; 903 fhold(oldfde->fde_file); 904 newfde = &fdp->fd_ofiles[new]; 905 delfp = newfde->fde_file; 906 907 /* 908 * Duplicate the source descriptor. 909 */ 910#ifdef CAPABILITIES 911 seq_write_begin(&newfde->fde_seq); 912#endif 913 filecaps_free(&newfde->fde_caps); 914 memcpy(newfde, oldfde, fde_change_size); 915 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps, true); 916 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 917 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 918 else 919 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 920#ifdef CAPABILITIES 921 seq_write_end(&newfde->fde_seq); 922#endif 923 td->td_retval[0] = new; 924 925 error = 0; 926 927 if (delfp != NULL) { 928 (void) closefp(fdp, new, delfp, td, 1); 929 FILEDESC_UNLOCK_ASSERT(fdp); 930 } else { 931unlock: 932 FILEDESC_XUNLOCK(fdp); 933 } 934 935 return (error); 936} 937 938/* 939 * If sigio is on the list associated with a process or process group, 940 * disable signalling from the device, remove sigio from the list and 941 * free sigio. 942 */ 943void 944funsetown(struct sigio **sigiop) 945{ 946 struct sigio *sigio; 947 948 if (*sigiop == NULL) 949 return; 950 SIGIO_LOCK(); 951 sigio = *sigiop; 952 if (sigio == NULL) { 953 SIGIO_UNLOCK(); 954 return; 955 } 956 *(sigio->sio_myref) = NULL; 957 if ((sigio)->sio_pgid < 0) { 958 struct pgrp *pg = (sigio)->sio_pgrp; 959 PGRP_LOCK(pg); 960 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 961 sigio, sio_pgsigio); 962 PGRP_UNLOCK(pg); 963 } else { 964 struct proc *p = (sigio)->sio_proc; 965 PROC_LOCK(p); 966 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 967 sigio, sio_pgsigio); 968 PROC_UNLOCK(p); 969 } 970 SIGIO_UNLOCK(); 971 crfree(sigio->sio_ucred); 972 free(sigio, M_SIGIO); 973} 974 975/* 976 * Free a list of sigio structures. 977 * We only need to lock the SIGIO_LOCK because we have made ourselves 978 * inaccessible to callers of fsetown and therefore do not need to lock 979 * the proc or pgrp struct for the list manipulation. 980 */ 981void 982funsetownlst(struct sigiolst *sigiolst) 983{ 984 struct proc *p; 985 struct pgrp *pg; 986 struct sigio *sigio; 987 988 sigio = SLIST_FIRST(sigiolst); 989 if (sigio == NULL) 990 return; 991 p = NULL; 992 pg = NULL; 993 994 /* 995 * Every entry of the list should belong 996 * to a single proc or pgrp. 997 */ 998 if (sigio->sio_pgid < 0) { 999 pg = sigio->sio_pgrp; 1000 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1001 } else /* if (sigio->sio_pgid > 0) */ { 1002 p = sigio->sio_proc; 1003 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1004 } 1005 1006 SIGIO_LOCK(); 1007 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1008 *(sigio->sio_myref) = NULL; 1009 if (pg != NULL) { 1010 KASSERT(sigio->sio_pgid < 0, 1011 ("Proc sigio in pgrp sigio list")); 1012 KASSERT(sigio->sio_pgrp == pg, 1013 ("Bogus pgrp in sigio list")); 1014 PGRP_LOCK(pg); 1015 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1016 sio_pgsigio); 1017 PGRP_UNLOCK(pg); 1018 } else /* if (p != NULL) */ { 1019 KASSERT(sigio->sio_pgid > 0, 1020 ("Pgrp sigio in proc sigio list")); 1021 KASSERT(sigio->sio_proc == p, 1022 ("Bogus proc in sigio list")); 1023 PROC_LOCK(p); 1024 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1025 sio_pgsigio); 1026 PROC_UNLOCK(p); 1027 } 1028 SIGIO_UNLOCK(); 1029 crfree(sigio->sio_ucred); 1030 free(sigio, M_SIGIO); 1031 SIGIO_LOCK(); 1032 } 1033 SIGIO_UNLOCK(); 1034} 1035 1036/* 1037 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1038 * 1039 * After permission checking, add a sigio structure to the sigio list for 1040 * the process or process group. 1041 */ 1042int 1043fsetown(pid_t pgid, struct sigio **sigiop) 1044{ 1045 struct proc *proc; 1046 struct pgrp *pgrp; 1047 struct sigio *sigio; 1048 int ret; 1049 1050 if (pgid == 0) { 1051 funsetown(sigiop); 1052 return (0); 1053 } 1054 1055 ret = 0; 1056 1057 /* Allocate and fill in the new sigio out of locks. */ 1058 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1059 sigio->sio_pgid = pgid; 1060 sigio->sio_ucred = crhold(curthread->td_ucred); 1061 sigio->sio_myref = sigiop; 1062 1063 sx_slock(&proctree_lock); 1064 if (pgid > 0) { 1065 proc = pfind(pgid); 1066 if (proc == NULL) { 1067 ret = ESRCH; 1068 goto fail; 1069 } 1070 1071 /* 1072 * Policy - Don't allow a process to FSETOWN a process 1073 * in another session. 1074 * 1075 * Remove this test to allow maximum flexibility or 1076 * restrict FSETOWN to the current process or process 1077 * group for maximum safety. 1078 */ 1079 PROC_UNLOCK(proc); 1080 if (proc->p_session != curthread->td_proc->p_session) { 1081 ret = EPERM; 1082 goto fail; 1083 } 1084 1085 pgrp = NULL; 1086 } else /* if (pgid < 0) */ { 1087 pgrp = pgfind(-pgid); 1088 if (pgrp == NULL) { 1089 ret = ESRCH; 1090 goto fail; 1091 } 1092 PGRP_UNLOCK(pgrp); 1093 1094 /* 1095 * Policy - Don't allow a process to FSETOWN a process 1096 * in another session. 1097 * 1098 * Remove this test to allow maximum flexibility or 1099 * restrict FSETOWN to the current process or process 1100 * group for maximum safety. 1101 */ 1102 if (pgrp->pg_session != curthread->td_proc->p_session) { 1103 ret = EPERM; 1104 goto fail; 1105 } 1106 1107 proc = NULL; 1108 } 1109 funsetown(sigiop); 1110 if (pgid > 0) { 1111 PROC_LOCK(proc); 1112 /* 1113 * Since funsetownlst() is called without the proctree 1114 * locked, we need to check for P_WEXIT. 1115 * XXX: is ESRCH correct? 1116 */ 1117 if ((proc->p_flag & P_WEXIT) != 0) { 1118 PROC_UNLOCK(proc); 1119 ret = ESRCH; 1120 goto fail; 1121 } 1122 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1123 sigio->sio_proc = proc; 1124 PROC_UNLOCK(proc); 1125 } else { 1126 PGRP_LOCK(pgrp); 1127 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1128 sigio->sio_pgrp = pgrp; 1129 PGRP_UNLOCK(pgrp); 1130 } 1131 sx_sunlock(&proctree_lock); 1132 SIGIO_LOCK(); 1133 *sigiop = sigio; 1134 SIGIO_UNLOCK(); 1135 return (0); 1136 1137fail: 1138 sx_sunlock(&proctree_lock); 1139 crfree(sigio->sio_ucred); 1140 free(sigio, M_SIGIO); 1141 return (ret); 1142} 1143 1144/* 1145 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1146 */ 1147pid_t 1148fgetown(sigiop) 1149 struct sigio **sigiop; 1150{ 1151 pid_t pgid; 1152 1153 SIGIO_LOCK(); 1154 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1155 SIGIO_UNLOCK(); 1156 return (pgid); 1157} 1158 1159/* 1160 * Function drops the filedesc lock on return. 1161 */ 1162static int 1163closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1164 int holdleaders) 1165{ 1166 int error; 1167 1168 FILEDESC_XLOCK_ASSERT(fdp); 1169 1170 if (holdleaders) { 1171 if (td->td_proc->p_fdtol != NULL) { 1172 /* 1173 * Ask fdfree() to sleep to ensure that all relevant 1174 * process leaders can be traversed in closef(). 1175 */ 1176 fdp->fd_holdleaderscount++; 1177 } else { 1178 holdleaders = 0; 1179 } 1180 } 1181 1182 /* 1183 * We now hold the fp reference that used to be owned by the 1184 * descriptor array. We have to unlock the FILEDESC *AFTER* 1185 * knote_fdclose to prevent a race of the fd getting opened, a knote 1186 * added, and deleteing a knote for the new fd. 1187 */ 1188 knote_fdclose(td, fd); 1189 1190 /* 1191 * We need to notify mqueue if the object is of type mqueue. 1192 */ 1193 if (fp->f_type == DTYPE_MQUEUE) 1194 mq_fdclose(td, fd, fp); 1195 FILEDESC_XUNLOCK(fdp); 1196 1197 error = closef(fp, td); 1198 if (holdleaders) { 1199 FILEDESC_XLOCK(fdp); 1200 fdp->fd_holdleaderscount--; 1201 if (fdp->fd_holdleaderscount == 0 && 1202 fdp->fd_holdleaderswakeup != 0) { 1203 fdp->fd_holdleaderswakeup = 0; 1204 wakeup(&fdp->fd_holdleaderscount); 1205 } 1206 FILEDESC_XUNLOCK(fdp); 1207 } 1208 return (error); 1209} 1210 1211/* 1212 * Close a file descriptor. 1213 */ 1214#ifndef _SYS_SYSPROTO_H_ 1215struct close_args { 1216 int fd; 1217}; 1218#endif 1219/* ARGSUSED */ 1220int 1221sys_close(struct thread *td, struct close_args *uap) 1222{ 1223 1224 return (kern_close(td, uap->fd)); 1225} 1226 1227int 1228kern_close(struct thread *td, int fd) 1229{ 1230 struct filedesc *fdp; 1231 struct file *fp; 1232 1233 fdp = td->td_proc->p_fd; 1234 1235 AUDIT_SYSCLOSE(td, fd); 1236 1237 FILEDESC_XLOCK(fdp); 1238 if ((fp = fget_locked(fdp, fd)) == NULL) { 1239 FILEDESC_XUNLOCK(fdp); 1240 return (EBADF); 1241 } 1242 fdfree(fdp, fd); 1243 1244 /* closefp() drops the FILEDESC lock for us. */ 1245 return (closefp(fdp, fd, fp, td, 1)); 1246} 1247 1248/* 1249 * Close open file descriptors. 1250 */ 1251#ifndef _SYS_SYSPROTO_H_ 1252struct closefrom_args { 1253 int lowfd; 1254}; 1255#endif 1256/* ARGSUSED */ 1257int 1258sys_closefrom(struct thread *td, struct closefrom_args *uap) 1259{ 1260 struct filedesc *fdp; 1261 int fd; 1262 1263 fdp = td->td_proc->p_fd; 1264 AUDIT_ARG_FD(uap->lowfd); 1265 1266 /* 1267 * Treat negative starting file descriptor values identical to 1268 * closefrom(0) which closes all files. 1269 */ 1270 if (uap->lowfd < 0) 1271 uap->lowfd = 0; 1272 FILEDESC_SLOCK(fdp); 1273 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1274 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1275 FILEDESC_SUNLOCK(fdp); 1276 (void)kern_close(td, fd); 1277 FILEDESC_SLOCK(fdp); 1278 } 1279 } 1280 FILEDESC_SUNLOCK(fdp); 1281 return (0); 1282} 1283 1284#if defined(COMPAT_43) 1285/* 1286 * Return status information about a file descriptor. 1287 */ 1288#ifndef _SYS_SYSPROTO_H_ 1289struct ofstat_args { 1290 int fd; 1291 struct ostat *sb; 1292}; 1293#endif 1294/* ARGSUSED */ 1295int 1296ofstat(struct thread *td, struct ofstat_args *uap) 1297{ 1298 struct ostat oub; 1299 struct stat ub; 1300 int error; 1301 1302 error = kern_fstat(td, uap->fd, &ub); 1303 if (error == 0) { 1304 cvtstat(&ub, &oub); 1305 error = copyout(&oub, uap->sb, sizeof(oub)); 1306 } 1307 return (error); 1308} 1309#endif /* COMPAT_43 */ 1310 1311/* 1312 * Return status information about a file descriptor. 1313 */ 1314#ifndef _SYS_SYSPROTO_H_ 1315struct fstat_args { 1316 int fd; 1317 struct stat *sb; 1318}; 1319#endif 1320/* ARGSUSED */ 1321int 1322sys_fstat(struct thread *td, struct fstat_args *uap) 1323{ 1324 struct stat ub; 1325 int error; 1326 1327 error = kern_fstat(td, uap->fd, &ub); 1328 if (error == 0) 1329 error = copyout(&ub, uap->sb, sizeof(ub)); 1330 return (error); 1331} 1332 1333int 1334kern_fstat(struct thread *td, int fd, struct stat *sbp) 1335{ 1336 struct file *fp; 1337 cap_rights_t rights; 1338 int error; 1339 1340 AUDIT_ARG_FD(fd); 1341 1342 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1343 if (error != 0) 1344 return (error); 1345 1346 AUDIT_ARG_FILE(td->td_proc, fp); 1347 1348 error = fo_stat(fp, sbp, td->td_ucred, td); 1349 fdrop(fp, td); 1350#ifdef KTRACE 1351 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1352 ktrstat(sbp); 1353#endif 1354 return (error); 1355} 1356 1357/* 1358 * Return status information about a file descriptor. 1359 */ 1360#ifndef _SYS_SYSPROTO_H_ 1361struct nfstat_args { 1362 int fd; 1363 struct nstat *sb; 1364}; 1365#endif 1366/* ARGSUSED */ 1367int 1368sys_nfstat(struct thread *td, struct nfstat_args *uap) 1369{ 1370 struct nstat nub; 1371 struct stat ub; 1372 int error; 1373 1374 error = kern_fstat(td, uap->fd, &ub); 1375 if (error == 0) { 1376 cvtnstat(&ub, &nub); 1377 error = copyout(&nub, uap->sb, sizeof(nub)); 1378 } 1379 return (error); 1380} 1381 1382/* 1383 * Return pathconf information about a file descriptor. 1384 */ 1385#ifndef _SYS_SYSPROTO_H_ 1386struct fpathconf_args { 1387 int fd; 1388 int name; 1389}; 1390#endif 1391/* ARGSUSED */ 1392int 1393sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1394{ 1395 1396 return (kern_fpathconf(td, uap->fd, uap->name)); 1397} 1398 1399int 1400kern_fpathconf(struct thread *td, int fd, int name) 1401{ 1402 struct file *fp; 1403 struct vnode *vp; 1404 cap_rights_t rights; 1405 int error; 1406 1407 error = fget(td, fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1408 if (error != 0) 1409 return (error); 1410 1411 if (name == _PC_ASYNC_IO) { 1412 td->td_retval[0] = _POSIX_ASYNCHRONOUS_IO; 1413 goto out; 1414 } 1415 vp = fp->f_vnode; 1416 if (vp != NULL) { 1417 vn_lock(vp, LK_SHARED | LK_RETRY); 1418 error = VOP_PATHCONF(vp, name, td->td_retval); 1419 VOP_UNLOCK(vp, 0); 1420 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1421 if (name != _PC_PIPE_BUF) { 1422 error = EINVAL; 1423 } else { 1424 td->td_retval[0] = PIPE_BUF; 1425 error = 0; 1426 } 1427 } else { 1428 error = EOPNOTSUPP; 1429 } 1430out: 1431 fdrop(fp, td); 1432 return (error); 1433} 1434 1435/* 1436 * Initialize filecaps structure. 1437 */ 1438void 1439filecaps_init(struct filecaps *fcaps) 1440{ 1441 1442 bzero(fcaps, sizeof(*fcaps)); 1443 fcaps->fc_nioctls = -1; 1444} 1445 1446/* 1447 * Copy filecaps structure allocating memory for ioctls array if needed. 1448 * 1449 * The last parameter indicates whether the fdtable is locked. If it is not and 1450 * ioctls are encountered, copying fails and the caller must lock the table. 1451 * 1452 * Note that if the table was not locked, the caller has to check the relevant 1453 * sequence counter to determine whether the operation was successful. 1454 */ 1455bool 1456filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1457{ 1458 size_t size; 1459 1460 if (src->fc_ioctls != NULL && !locked) 1461 return (false); 1462 *dst = *src; 1463 if (src->fc_ioctls == NULL) 1464 return (true); 1465 1466 KASSERT(src->fc_nioctls > 0, 1467 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1468 1469 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1470 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1471 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1472 return (true); 1473} 1474 1475/* 1476 * Move filecaps structure to the new place and clear the old place. 1477 */ 1478void 1479filecaps_move(struct filecaps *src, struct filecaps *dst) 1480{ 1481 1482 *dst = *src; 1483 bzero(src, sizeof(*src)); 1484} 1485 1486/* 1487 * Fill the given filecaps structure with full rights. 1488 */ 1489static void 1490filecaps_fill(struct filecaps *fcaps) 1491{ 1492 1493 CAP_ALL(&fcaps->fc_rights); 1494 fcaps->fc_ioctls = NULL; 1495 fcaps->fc_nioctls = -1; 1496 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1497} 1498 1499/* 1500 * Free memory allocated within filecaps structure. 1501 */ 1502void 1503filecaps_free(struct filecaps *fcaps) 1504{ 1505 1506 free(fcaps->fc_ioctls, M_FILECAPS); 1507 bzero(fcaps, sizeof(*fcaps)); 1508} 1509 1510/* 1511 * Validate the given filecaps structure. 1512 */ 1513static void 1514filecaps_validate(const struct filecaps *fcaps, const char *func) 1515{ 1516 1517 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1518 ("%s: invalid rights", func)); 1519 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1520 ("%s: invalid fcntls", func)); 1521 KASSERT(fcaps->fc_fcntls == 0 || 1522 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1523 ("%s: fcntls without CAP_FCNTL", func)); 1524 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1525 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1526 ("%s: invalid ioctls", func)); 1527 KASSERT(fcaps->fc_nioctls == 0 || 1528 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1529 ("%s: ioctls without CAP_IOCTL", func)); 1530} 1531 1532static void 1533fdgrowtable_exp(struct filedesc *fdp, int nfd) 1534{ 1535 int nfd1; 1536 1537 FILEDESC_XLOCK_ASSERT(fdp); 1538 1539 nfd1 = fdp->fd_nfiles * 2; 1540 if (nfd1 < nfd) 1541 nfd1 = nfd; 1542 fdgrowtable(fdp, nfd1); 1543} 1544 1545/* 1546 * Grow the file table to accommodate (at least) nfd descriptors. 1547 */ 1548static void 1549fdgrowtable(struct filedesc *fdp, int nfd) 1550{ 1551 struct filedesc0 *fdp0; 1552 struct freetable *ft; 1553 struct fdescenttbl *ntable; 1554 struct fdescenttbl *otable; 1555 int nnfiles, onfiles; 1556 NDSLOTTYPE *nmap, *omap; 1557 1558 /* 1559 * If lastfile is -1 this struct filedesc was just allocated and we are 1560 * growing it to accommodate for the one we are going to copy from. There 1561 * is no need to have a lock on this one as it's not visible to anyone. 1562 */ 1563 if (fdp->fd_lastfile != -1) 1564 FILEDESC_XLOCK_ASSERT(fdp); 1565 1566 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1567 1568 /* save old values */ 1569 onfiles = fdp->fd_nfiles; 1570 otable = fdp->fd_files; 1571 omap = fdp->fd_map; 1572 1573 /* compute the size of the new table */ 1574 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1575 if (nnfiles <= onfiles) 1576 /* the table is already large enough */ 1577 return; 1578 1579 /* 1580 * Allocate a new table. We need enough space for the number of 1581 * entries, file entries themselves and the struct freetable we will use 1582 * when we decommission the table and place it on the freelist. 1583 * We place the struct freetable in the middle so we don't have 1584 * to worry about padding. 1585 */ 1586 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1587 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1588 sizeof(struct freetable), 1589 M_FILEDESC, M_ZERO | M_WAITOK); 1590 /* copy the old data */ 1591 ntable->fdt_nfiles = nnfiles; 1592 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1593 onfiles * sizeof(ntable->fdt_ofiles[0])); 1594 1595 /* 1596 * Allocate a new map only if the old is not large enough. It will 1597 * grow at a slower rate than the table as it can map more 1598 * entries than the table can hold. 1599 */ 1600 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1601 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1602 M_ZERO | M_WAITOK); 1603 /* copy over the old data and update the pointer */ 1604 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1605 fdp->fd_map = nmap; 1606 } 1607 1608 /* 1609 * Make sure that ntable is correctly initialized before we replace 1610 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1611 * data. 1612 */ 1613 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1614 1615 /* 1616 * Do not free the old file table, as some threads may still 1617 * reference entries within it. Instead, place it on a freelist 1618 * which will be processed when the struct filedesc is released. 1619 * 1620 * Note that if onfiles == NDFILE, we're dealing with the original 1621 * static allocation contained within (struct filedesc0 *)fdp, 1622 * which must not be freed. 1623 */ 1624 if (onfiles > NDFILE) { 1625 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1626 fdp0 = (struct filedesc0 *)fdp; 1627 ft->ft_table = otable; 1628 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1629 } 1630 /* 1631 * The map does not have the same possibility of threads still 1632 * holding references to it. So always free it as long as it 1633 * does not reference the original static allocation. 1634 */ 1635 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1636 free(omap, M_FILEDESC); 1637} 1638 1639/* 1640 * Allocate a file descriptor for the process. 1641 */ 1642int 1643fdalloc(struct thread *td, int minfd, int *result) 1644{ 1645 struct proc *p = td->td_proc; 1646 struct filedesc *fdp = p->p_fd; 1647 int fd, maxfd, allocfd; 1648#ifdef RACCT 1649 int error; 1650#endif 1651 1652 FILEDESC_XLOCK_ASSERT(fdp); 1653 1654 if (fdp->fd_freefile > minfd) 1655 minfd = fdp->fd_freefile; 1656 1657 maxfd = getmaxfd(td); 1658 1659 /* 1660 * Search the bitmap for a free descriptor starting at minfd. 1661 * If none is found, grow the file table. 1662 */ 1663 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1664 if (fd >= maxfd) 1665 return (EMFILE); 1666 if (fd >= fdp->fd_nfiles) { 1667 allocfd = min(fd * 2, maxfd); 1668#ifdef RACCT 1669 if (racct_enable) { 1670 PROC_LOCK(p); 1671 error = racct_set(p, RACCT_NOFILE, allocfd); 1672 PROC_UNLOCK(p); 1673 if (error != 0) 1674 return (EMFILE); 1675 } 1676#endif 1677 /* 1678 * fd is already equal to first free descriptor >= minfd, so 1679 * we only need to grow the table and we are done. 1680 */ 1681 fdgrowtable_exp(fdp, allocfd); 1682 } 1683 1684 /* 1685 * Perform some sanity checks, then mark the file descriptor as 1686 * used and return it to the caller. 1687 */ 1688 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1689 ("invalid descriptor %d", fd)); 1690 KASSERT(!fdisused(fdp, fd), 1691 ("fd_first_free() returned non-free descriptor")); 1692 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1693 ("file descriptor isn't free")); 1694 fdused(fdp, fd); 1695 *result = fd; 1696 return (0); 1697} 1698 1699/* 1700 * Allocate n file descriptors for the process. 1701 */ 1702int 1703fdallocn(struct thread *td, int minfd, int *fds, int n) 1704{ 1705 struct proc *p = td->td_proc; 1706 struct filedesc *fdp = p->p_fd; 1707 int i; 1708 1709 FILEDESC_XLOCK_ASSERT(fdp); 1710 1711 for (i = 0; i < n; i++) 1712 if (fdalloc(td, 0, &fds[i]) != 0) 1713 break; 1714 1715 if (i < n) { 1716 for (i--; i >= 0; i--) 1717 fdunused(fdp, fds[i]); 1718 return (EMFILE); 1719 } 1720 1721 return (0); 1722} 1723 1724/* 1725 * Create a new open file structure and allocate a file descriptor for the 1726 * process that refers to it. We add one reference to the file for the 1727 * descriptor table and one reference for resultfp. This is to prevent us 1728 * being preempted and the entry in the descriptor table closed after we 1729 * release the FILEDESC lock. 1730 */ 1731int 1732falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1733 struct filecaps *fcaps) 1734{ 1735 struct file *fp; 1736 int error, fd; 1737 1738 error = falloc_noinstall(td, &fp); 1739 if (error) 1740 return (error); /* no reference held on error */ 1741 1742 error = finstall(td, fp, &fd, flags, fcaps); 1743 if (error) { 1744 fdrop(fp, td); /* one reference (fp only) */ 1745 return (error); 1746 } 1747 1748 if (resultfp != NULL) 1749 *resultfp = fp; /* copy out result */ 1750 else 1751 fdrop(fp, td); /* release local reference */ 1752 1753 if (resultfd != NULL) 1754 *resultfd = fd; 1755 1756 return (0); 1757} 1758 1759/* 1760 * Create a new open file structure without allocating a file descriptor. 1761 */ 1762int 1763falloc_noinstall(struct thread *td, struct file **resultfp) 1764{ 1765 struct file *fp; 1766 int maxuserfiles = maxfiles - (maxfiles / 20); 1767 int openfiles_new; 1768 static struct timeval lastfail; 1769 static int curfail; 1770 1771 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1772 1773 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1774 if ((openfiles_new >= maxuserfiles && 1775 priv_check(td, PRIV_MAXFILES) != 0) || 1776 openfiles_new >= maxfiles) { 1777 atomic_subtract_int(&openfiles, 1); 1778 if (ppsratecheck(&lastfail, &curfail, 1)) { 1779 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1780 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1781 } 1782 return (ENFILE); 1783 } 1784 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1785 refcount_init(&fp->f_count, 1); 1786 fp->f_cred = crhold(td->td_ucred); 1787 fp->f_ops = &badfileops; 1788 *resultfp = fp; 1789 return (0); 1790} 1791 1792/* 1793 * Install a file in a file descriptor table. 1794 */ 1795void 1796_finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1797 struct filecaps *fcaps) 1798{ 1799 struct filedescent *fde; 1800 1801 MPASS(fp != NULL); 1802 if (fcaps != NULL) 1803 filecaps_validate(fcaps, __func__); 1804 FILEDESC_XLOCK_ASSERT(fdp); 1805 1806 fde = &fdp->fd_ofiles[fd]; 1807#ifdef CAPABILITIES 1808 seq_write_begin(&fde->fde_seq); 1809#endif 1810 fde->fde_file = fp; 1811 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1812 if (fcaps != NULL) 1813 filecaps_move(fcaps, &fde->fde_caps); 1814 else 1815 filecaps_fill(&fde->fde_caps); 1816#ifdef CAPABILITIES 1817 seq_write_end(&fde->fde_seq); 1818#endif 1819} 1820 1821int 1822finstall(struct thread *td, struct file *fp, int *fd, int flags, 1823 struct filecaps *fcaps) 1824{ 1825 struct filedesc *fdp = td->td_proc->p_fd; 1826 int error; 1827 1828 MPASS(fd != NULL); 1829 1830 FILEDESC_XLOCK(fdp); 1831 if ((error = fdalloc(td, 0, fd))) { 1832 FILEDESC_XUNLOCK(fdp); 1833 return (error); 1834 } 1835 fhold(fp); 1836 _finstall(fdp, fp, *fd, flags, fcaps); 1837 FILEDESC_XUNLOCK(fdp); 1838 return (0); 1839} 1840 1841/* 1842 * Build a new filedesc structure from another. 1843 * Copy the current, root, and jail root vnode references. 1844 * 1845 * If fdp is not NULL, return with it shared locked. 1846 */ 1847struct filedesc * 1848fdinit(struct filedesc *fdp, bool prepfiles) 1849{ 1850 struct filedesc0 *newfdp0; 1851 struct filedesc *newfdp; 1852 1853 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1854 newfdp = &newfdp0->fd_fd; 1855 1856 /* Create the file descriptor table. */ 1857 FILEDESC_LOCK_INIT(newfdp); 1858 refcount_init(&newfdp->fd_refcnt, 1); 1859 refcount_init(&newfdp->fd_holdcnt, 1); 1860 newfdp->fd_cmask = CMASK; 1861 newfdp->fd_map = newfdp0->fd_dmap; 1862 newfdp->fd_lastfile = -1; 1863 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1864 newfdp->fd_files->fdt_nfiles = NDFILE; 1865 1866 if (fdp == NULL) 1867 return (newfdp); 1868 1869 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1870 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1871 1872 FILEDESC_SLOCK(fdp); 1873 newfdp->fd_cdir = fdp->fd_cdir; 1874 if (newfdp->fd_cdir) 1875 vrefact(newfdp->fd_cdir); 1876 newfdp->fd_rdir = fdp->fd_rdir; 1877 if (newfdp->fd_rdir) 1878 vrefact(newfdp->fd_rdir); 1879 newfdp->fd_jdir = fdp->fd_jdir; 1880 if (newfdp->fd_jdir) 1881 vrefact(newfdp->fd_jdir); 1882 1883 if (!prepfiles) { 1884 FILEDESC_SUNLOCK(fdp); 1885 } else { 1886 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1887 FILEDESC_SUNLOCK(fdp); 1888 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1889 FILEDESC_SLOCK(fdp); 1890 } 1891 } 1892 1893 return (newfdp); 1894} 1895 1896static struct filedesc * 1897fdhold(struct proc *p) 1898{ 1899 struct filedesc *fdp; 1900 1901 PROC_LOCK_ASSERT(p, MA_OWNED); 1902 fdp = p->p_fd; 1903 if (fdp != NULL) 1904 refcount_acquire(&fdp->fd_holdcnt); 1905 return (fdp); 1906} 1907 1908static void 1909fddrop(struct filedesc *fdp) 1910{ 1911 1912 if (fdp->fd_holdcnt > 1) { 1913 if (refcount_release(&fdp->fd_holdcnt) == 0) 1914 return; 1915 } 1916 1917 FILEDESC_LOCK_DESTROY(fdp); 1918 uma_zfree(filedesc0_zone, fdp); 1919} 1920 1921/* 1922 * Share a filedesc structure. 1923 */ 1924struct filedesc * 1925fdshare(struct filedesc *fdp) 1926{ 1927 1928 refcount_acquire(&fdp->fd_refcnt); 1929 return (fdp); 1930} 1931 1932/* 1933 * Unshare a filedesc structure, if necessary by making a copy 1934 */ 1935void 1936fdunshare(struct thread *td) 1937{ 1938 struct filedesc *tmp; 1939 struct proc *p = td->td_proc; 1940 1941 if (p->p_fd->fd_refcnt == 1) 1942 return; 1943 1944 tmp = fdcopy(p->p_fd); 1945 fdescfree(td); 1946 p->p_fd = tmp; 1947} 1948 1949void 1950fdinstall_remapped(struct thread *td, struct filedesc *fdp) 1951{ 1952 1953 fdescfree(td); 1954 td->td_proc->p_fd = fdp; 1955} 1956 1957/* 1958 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1959 * this is to ease callers, not catch errors. 1960 */ 1961struct filedesc * 1962fdcopy(struct filedesc *fdp) 1963{ 1964 struct filedesc *newfdp; 1965 struct filedescent *nfde, *ofde; 1966 int i; 1967 1968 MPASS(fdp != NULL); 1969 1970 newfdp = fdinit(fdp, true); 1971 /* copy all passable descriptors (i.e. not kqueue) */ 1972 newfdp->fd_freefile = -1; 1973 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1974 ofde = &fdp->fd_ofiles[i]; 1975 if (ofde->fde_file == NULL || 1976 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 1977 if (newfdp->fd_freefile == -1) 1978 newfdp->fd_freefile = i; 1979 continue; 1980 } 1981 nfde = &newfdp->fd_ofiles[i]; 1982 *nfde = *ofde; 1983 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 1984 fhold(nfde->fde_file); 1985 fdused_init(newfdp, i); 1986 newfdp->fd_lastfile = i; 1987 } 1988 if (newfdp->fd_freefile == -1) 1989 newfdp->fd_freefile = i; 1990 newfdp->fd_cmask = fdp->fd_cmask; 1991 FILEDESC_SUNLOCK(fdp); 1992 return (newfdp); 1993} 1994 1995/* 1996 * Copies a filedesc structure, while remapping all file descriptors 1997 * stored inside using a translation table. 1998 * 1999 * File descriptors are copied over to the new file descriptor table, 2000 * regardless of whether the close-on-exec flag is set. 2001 */ 2002int 2003fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2004 struct filedesc **ret) 2005{ 2006 struct filedesc *newfdp; 2007 struct filedescent *nfde, *ofde; 2008 int error, i; 2009 2010 MPASS(fdp != NULL); 2011 2012 newfdp = fdinit(fdp, true); 2013 if (nfds > fdp->fd_lastfile + 1) { 2014 /* New table cannot be larger than the old one. */ 2015 error = E2BIG; 2016 goto bad; 2017 } 2018 /* Copy all passable descriptors (i.e. not kqueue). */ 2019 newfdp->fd_freefile = nfds; 2020 for (i = 0; i < nfds; ++i) { 2021 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2022 /* File descriptor out of bounds. */ 2023 error = EBADF; 2024 goto bad; 2025 } 2026 ofde = &fdp->fd_ofiles[fds[i]]; 2027 if (ofde->fde_file == NULL) { 2028 /* Unused file descriptor. */ 2029 error = EBADF; 2030 goto bad; 2031 } 2032 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2033 /* File descriptor cannot be passed. */ 2034 error = EINVAL; 2035 goto bad; 2036 } 2037 nfde = &newfdp->fd_ofiles[i]; 2038 *nfde = *ofde; 2039 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2040 fhold(nfde->fde_file); 2041 fdused_init(newfdp, i); 2042 newfdp->fd_lastfile = i; 2043 } 2044 newfdp->fd_cmask = fdp->fd_cmask; 2045 FILEDESC_SUNLOCK(fdp); 2046 *ret = newfdp; 2047 return (0); 2048bad: 2049 FILEDESC_SUNLOCK(fdp); 2050 fdescfree_remapped(newfdp); 2051 return (error); 2052} 2053 2054/* 2055 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2056 * one of processes using it exits) and the table used to be shared. 2057 */ 2058static void 2059fdclearlocks(struct thread *td) 2060{ 2061 struct filedesc *fdp; 2062 struct filedesc_to_leader *fdtol; 2063 struct flock lf; 2064 struct file *fp; 2065 struct proc *p; 2066 struct vnode *vp; 2067 int i; 2068 2069 p = td->td_proc; 2070 fdp = p->p_fd; 2071 fdtol = p->p_fdtol; 2072 MPASS(fdtol != NULL); 2073 2074 FILEDESC_XLOCK(fdp); 2075 KASSERT(fdtol->fdl_refcount > 0, 2076 ("filedesc_to_refcount botch: fdl_refcount=%d", 2077 fdtol->fdl_refcount)); 2078 if (fdtol->fdl_refcount == 1 && 2079 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2080 for (i = 0; i <= fdp->fd_lastfile; i++) { 2081 fp = fdp->fd_ofiles[i].fde_file; 2082 if (fp == NULL || fp->f_type != DTYPE_VNODE) 2083 continue; 2084 fhold(fp); 2085 FILEDESC_XUNLOCK(fdp); 2086 lf.l_whence = SEEK_SET; 2087 lf.l_start = 0; 2088 lf.l_len = 0; 2089 lf.l_type = F_UNLCK; 2090 vp = fp->f_vnode; 2091 (void) VOP_ADVLOCK(vp, 2092 (caddr_t)p->p_leader, F_UNLCK, 2093 &lf, F_POSIX); 2094 FILEDESC_XLOCK(fdp); 2095 fdrop(fp, td); 2096 } 2097 } 2098retry: 2099 if (fdtol->fdl_refcount == 1) { 2100 if (fdp->fd_holdleaderscount > 0 && 2101 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2102 /* 2103 * close() or kern_dup() has cleared a reference 2104 * in a shared file descriptor table. 2105 */ 2106 fdp->fd_holdleaderswakeup = 1; 2107 sx_sleep(&fdp->fd_holdleaderscount, 2108 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2109 goto retry; 2110 } 2111 if (fdtol->fdl_holdcount > 0) { 2112 /* 2113 * Ensure that fdtol->fdl_leader remains 2114 * valid in closef(). 2115 */ 2116 fdtol->fdl_wakeup = 1; 2117 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2118 "fdlhold", 0); 2119 goto retry; 2120 } 2121 } 2122 fdtol->fdl_refcount--; 2123 if (fdtol->fdl_refcount == 0 && 2124 fdtol->fdl_holdcount == 0) { 2125 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2126 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2127 } else 2128 fdtol = NULL; 2129 p->p_fdtol = NULL; 2130 FILEDESC_XUNLOCK(fdp); 2131 if (fdtol != NULL) 2132 free(fdtol, M_FILEDESC_TO_LEADER); 2133} 2134 2135/* 2136 * Release a filedesc structure. 2137 */ 2138static void 2139fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2140{ 2141 struct filedesc0 *fdp0; 2142 struct freetable *ft, *tft; 2143 struct filedescent *fde; 2144 struct file *fp; 2145 int i; 2146 2147 for (i = 0; i <= fdp->fd_lastfile; i++) { 2148 fde = &fdp->fd_ofiles[i]; 2149 fp = fde->fde_file; 2150 if (fp != NULL) { 2151 fdefree_last(fde); 2152 if (needclose) 2153 (void) closef(fp, td); 2154 else 2155 fdrop(fp, td); 2156 } 2157 } 2158 2159 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2160 free(fdp->fd_map, M_FILEDESC); 2161 if (fdp->fd_nfiles > NDFILE) 2162 free(fdp->fd_files, M_FILEDESC); 2163 2164 fdp0 = (struct filedesc0 *)fdp; 2165 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2166 free(ft->ft_table, M_FILEDESC); 2167 2168 fddrop(fdp); 2169} 2170 2171void 2172fdescfree(struct thread *td) 2173{ 2174 struct proc *p; 2175 struct filedesc *fdp; 2176 struct vnode *cdir, *jdir, *rdir; 2177 2178 p = td->td_proc; 2179 fdp = p->p_fd; 2180 MPASS(fdp != NULL); 2181 2182#ifdef RACCT 2183 if (racct_enable) { 2184 PROC_LOCK(p); 2185 racct_set(p, RACCT_NOFILE, 0); 2186 PROC_UNLOCK(p); 2187 } 2188#endif 2189 2190 if (p->p_fdtol != NULL) 2191 fdclearlocks(td); 2192 2193 PROC_LOCK(p); 2194 p->p_fd = NULL; 2195 PROC_UNLOCK(p); 2196 2197 if (refcount_release(&fdp->fd_refcnt) == 0) 2198 return; 2199 2200 FILEDESC_XLOCK(fdp); 2201 cdir = fdp->fd_cdir; 2202 fdp->fd_cdir = NULL; 2203 rdir = fdp->fd_rdir; 2204 fdp->fd_rdir = NULL; 2205 jdir = fdp->fd_jdir; 2206 fdp->fd_jdir = NULL; 2207 FILEDESC_XUNLOCK(fdp); 2208 2209 if (cdir != NULL) 2210 vrele(cdir); 2211 if (rdir != NULL) 2212 vrele(rdir); 2213 if (jdir != NULL) 2214 vrele(jdir); 2215 2216 fdescfree_fds(td, fdp, 1); 2217} 2218 2219void 2220fdescfree_remapped(struct filedesc *fdp) 2221{ 2222 2223 if (fdp->fd_cdir != NULL) 2224 vrele(fdp->fd_cdir); 2225 if (fdp->fd_rdir != NULL) 2226 vrele(fdp->fd_rdir); 2227 if (fdp->fd_jdir != NULL) 2228 vrele(fdp->fd_jdir); 2229 2230 fdescfree_fds(curthread, fdp, 0); 2231} 2232 2233/* 2234 * For setugid programs, we don't want to people to use that setugidness 2235 * to generate error messages which write to a file which otherwise would 2236 * otherwise be off-limits to the process. We check for filesystems where 2237 * the vnode can change out from under us after execve (like [lin]procfs). 2238 * 2239 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2240 * sufficient. We also don't check for setugidness since we know we are. 2241 */ 2242static bool 2243is_unsafe(struct file *fp) 2244{ 2245 struct vnode *vp; 2246 2247 if (fp->f_type != DTYPE_VNODE) 2248 return (false); 2249 2250 vp = fp->f_vnode; 2251 return ((vp->v_vflag & VV_PROCDEP) != 0); 2252} 2253 2254/* 2255 * Make this setguid thing safe, if at all possible. 2256 */ 2257void 2258fdsetugidsafety(struct thread *td) 2259{ 2260 struct filedesc *fdp; 2261 struct file *fp; 2262 int i; 2263 2264 fdp = td->td_proc->p_fd; 2265 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2266 MPASS(fdp->fd_nfiles >= 3); 2267 for (i = 0; i <= 2; i++) { 2268 fp = fdp->fd_ofiles[i].fde_file; 2269 if (fp != NULL && is_unsafe(fp)) { 2270 FILEDESC_XLOCK(fdp); 2271 knote_fdclose(td, i); 2272 /* 2273 * NULL-out descriptor prior to close to avoid 2274 * a race while close blocks. 2275 */ 2276 fdfree(fdp, i); 2277 FILEDESC_XUNLOCK(fdp); 2278 (void) closef(fp, td); 2279 } 2280 } 2281} 2282 2283/* 2284 * If a specific file object occupies a specific file descriptor, close the 2285 * file descriptor entry and drop a reference on the file object. This is a 2286 * convenience function to handle a subsequent error in a function that calls 2287 * falloc() that handles the race that another thread might have closed the 2288 * file descriptor out from under the thread creating the file object. 2289 */ 2290void 2291fdclose(struct thread *td, struct file *fp, int idx) 2292{ 2293 struct filedesc *fdp = td->td_proc->p_fd; 2294 2295 FILEDESC_XLOCK(fdp); 2296 if (fdp->fd_ofiles[idx].fde_file == fp) { 2297 fdfree(fdp, idx); 2298 FILEDESC_XUNLOCK(fdp); 2299 fdrop(fp, td); 2300 } else 2301 FILEDESC_XUNLOCK(fdp); 2302} 2303 2304/* 2305 * Close any files on exec? 2306 */ 2307void 2308fdcloseexec(struct thread *td) 2309{ 2310 struct filedesc *fdp; 2311 struct filedescent *fde; 2312 struct file *fp; 2313 int i; 2314 2315 fdp = td->td_proc->p_fd; 2316 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2317 for (i = 0; i <= fdp->fd_lastfile; i++) { 2318 fde = &fdp->fd_ofiles[i]; 2319 fp = fde->fde_file; 2320 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2321 (fde->fde_flags & UF_EXCLOSE))) { 2322 FILEDESC_XLOCK(fdp); 2323 fdfree(fdp, i); 2324 (void) closefp(fdp, i, fp, td, 0); 2325 FILEDESC_UNLOCK_ASSERT(fdp); 2326 } 2327 } 2328} 2329 2330/* 2331 * It is unsafe for set[ug]id processes to be started with file 2332 * descriptors 0..2 closed, as these descriptors are given implicit 2333 * significance in the Standard C library. fdcheckstd() will create a 2334 * descriptor referencing /dev/null for each of stdin, stdout, and 2335 * stderr that is not already open. 2336 */ 2337int 2338fdcheckstd(struct thread *td) 2339{ 2340 struct filedesc *fdp; 2341 register_t save; 2342 int i, error, devnull; 2343 2344 fdp = td->td_proc->p_fd; 2345 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2346 MPASS(fdp->fd_nfiles >= 3); 2347 devnull = -1; 2348 for (i = 0; i <= 2; i++) { 2349 if (fdp->fd_ofiles[i].fde_file != NULL) 2350 continue; 2351 2352 save = td->td_retval[0]; 2353 if (devnull != -1) { 2354 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2355 } else { 2356 error = kern_openat(td, AT_FDCWD, "/dev/null", 2357 UIO_SYSSPACE, O_RDWR, 0); 2358 if (error == 0) { 2359 devnull = td->td_retval[0]; 2360 KASSERT(devnull == i, ("we didn't get our fd")); 2361 } 2362 } 2363 td->td_retval[0] = save; 2364 if (error != 0) 2365 return (error); 2366 } 2367 return (0); 2368} 2369 2370/* 2371 * Internal form of close. Decrement reference count on file structure. 2372 * Note: td may be NULL when closing a file that was being passed in a 2373 * message. 2374 * 2375 * XXXRW: Giant is not required for the caller, but often will be held; this 2376 * makes it moderately likely the Giant will be recursed in the VFS case. 2377 */ 2378int 2379closef(struct file *fp, struct thread *td) 2380{ 2381 struct vnode *vp; 2382 struct flock lf; 2383 struct filedesc_to_leader *fdtol; 2384 struct filedesc *fdp; 2385 2386 /* 2387 * POSIX record locking dictates that any close releases ALL 2388 * locks owned by this process. This is handled by setting 2389 * a flag in the unlock to free ONLY locks obeying POSIX 2390 * semantics, and not to free BSD-style file locks. 2391 * If the descriptor was in a message, POSIX-style locks 2392 * aren't passed with the descriptor, and the thread pointer 2393 * will be NULL. Callers should be careful only to pass a 2394 * NULL thread pointer when there really is no owning 2395 * context that might have locks, or the locks will be 2396 * leaked. 2397 */ 2398 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2399 vp = fp->f_vnode; 2400 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2401 lf.l_whence = SEEK_SET; 2402 lf.l_start = 0; 2403 lf.l_len = 0; 2404 lf.l_type = F_UNLCK; 2405 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2406 F_UNLCK, &lf, F_POSIX); 2407 } 2408 fdtol = td->td_proc->p_fdtol; 2409 if (fdtol != NULL) { 2410 /* 2411 * Handle special case where file descriptor table is 2412 * shared between multiple process leaders. 2413 */ 2414 fdp = td->td_proc->p_fd; 2415 FILEDESC_XLOCK(fdp); 2416 for (fdtol = fdtol->fdl_next; 2417 fdtol != td->td_proc->p_fdtol; 2418 fdtol = fdtol->fdl_next) { 2419 if ((fdtol->fdl_leader->p_flag & 2420 P_ADVLOCK) == 0) 2421 continue; 2422 fdtol->fdl_holdcount++; 2423 FILEDESC_XUNLOCK(fdp); 2424 lf.l_whence = SEEK_SET; 2425 lf.l_start = 0; 2426 lf.l_len = 0; 2427 lf.l_type = F_UNLCK; 2428 vp = fp->f_vnode; 2429 (void) VOP_ADVLOCK(vp, 2430 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2431 F_POSIX); 2432 FILEDESC_XLOCK(fdp); 2433 fdtol->fdl_holdcount--; 2434 if (fdtol->fdl_holdcount == 0 && 2435 fdtol->fdl_wakeup != 0) { 2436 fdtol->fdl_wakeup = 0; 2437 wakeup(fdtol); 2438 } 2439 } 2440 FILEDESC_XUNLOCK(fdp); 2441 } 2442 } 2443 return (fdrop(fp, td)); 2444} 2445 2446/* 2447 * Initialize the file pointer with the specified properties. 2448 * 2449 * The ops are set with release semantics to be certain that the flags, type, 2450 * and data are visible when ops is. This is to prevent ops methods from being 2451 * called with bad data. 2452 */ 2453void 2454finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2455{ 2456 fp->f_data = data; 2457 fp->f_flag = flag; 2458 fp->f_type = type; 2459 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2460} 2461 2462int 2463fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2464 struct file **fpp, struct filecaps *havecapsp) 2465{ 2466 struct filedescent *fde; 2467 int error; 2468 2469 FILEDESC_LOCK_ASSERT(fdp); 2470 2471 fde = fdeget_locked(fdp, fd); 2472 if (fde == NULL) { 2473 error = EBADF; 2474 goto out; 2475 } 2476 2477#ifdef CAPABILITIES 2478 error = cap_check(cap_rights_fde(fde), needrightsp); 2479 if (error != 0) 2480 goto out; 2481#endif 2482 2483 if (havecapsp != NULL) 2484 filecaps_copy(&fde->fde_caps, havecapsp, true); 2485 2486 *fpp = fde->fde_file; 2487 2488 error = 0; 2489out: 2490 return (error); 2491} 2492 2493int 2494fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2495 struct file **fpp, struct filecaps *havecapsp) 2496{ 2497 struct filedesc *fdp = td->td_proc->p_fd; 2498 int error; 2499#ifndef CAPABILITIES 2500 error = fget_unlocked(fdp, fd, needrightsp, fpp, NULL); 2501 if (error == 0 && havecapsp != NULL) 2502 filecaps_fill(havecapsp); 2503#else 2504 struct file *fp; 2505 seq_t seq; 2506 2507 for (;;) { 2508 error = fget_unlocked(fdp, fd, needrightsp, &fp, &seq); 2509 if (error != 0) 2510 return (error); 2511 2512 if (havecapsp != NULL) { 2513 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2514 havecapsp, false)) { 2515 fdrop(fp, td); 2516 goto get_locked; 2517 } 2518 } 2519 2520 if (!fd_modified(fdp, fd, seq)) 2521 break; 2522 fdrop(fp, td); 2523 } 2524 2525 *fpp = fp; 2526 return (0); 2527 2528get_locked: 2529 FILEDESC_SLOCK(fdp); 2530 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2531 if (error == 0) 2532 fhold(*fpp); 2533 FILEDESC_SUNLOCK(fdp); 2534#endif 2535 return (error); 2536} 2537 2538int 2539fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2540 struct file **fpp, seq_t *seqp) 2541{ 2542#ifdef CAPABILITIES 2543 struct filedescent *fde; 2544#endif 2545 struct fdescenttbl *fdt; 2546 struct file *fp; 2547 u_int count; 2548#ifdef CAPABILITIES 2549 seq_t seq; 2550 cap_rights_t haverights; 2551 int error; 2552#endif 2553 2554 fdt = fdp->fd_files; 2555 if ((u_int)fd >= fdt->fdt_nfiles) 2556 return (EBADF); 2557 /* 2558 * Fetch the descriptor locklessly. We avoid fdrop() races by 2559 * never raising a refcount above 0. To accomplish this we have 2560 * to use a cmpset loop rather than an atomic_add. The descriptor 2561 * must be re-verified once we acquire a reference to be certain 2562 * that the identity is still correct and we did not lose a race 2563 * due to preemption. 2564 */ 2565 for (;;) { 2566#ifdef CAPABILITIES 2567 seq = seq_read(fd_seq(fdt, fd)); 2568 fde = &fdt->fdt_ofiles[fd]; 2569 haverights = *cap_rights_fde(fde); 2570 fp = fde->fde_file; 2571 if (!seq_consistent(fd_seq(fdt, fd), seq)) 2572 continue; 2573#else 2574 fp = fdt->fdt_ofiles[fd].fde_file; 2575#endif 2576 if (fp == NULL) 2577 return (EBADF); 2578#ifdef CAPABILITIES 2579 error = cap_check(&haverights, needrightsp); 2580 if (error != 0) 2581 return (error); 2582#endif 2583 count = fp->f_count; 2584 retry: 2585 if (count == 0) { 2586 /* 2587 * Force a reload. Other thread could reallocate the 2588 * table before this fd was closed, so it possible that 2589 * there is a stale fp pointer in cached version. 2590 */ 2591 fdt = *(struct fdescenttbl * volatile *)&(fdp->fd_files); 2592 continue; 2593 } 2594 /* 2595 * Use an acquire barrier to force re-reading of fdt so it is 2596 * refreshed for verification. 2597 */ 2598 if (atomic_fcmpset_acq_int(&fp->f_count, &count, count + 1) == 0) 2599 goto retry; 2600 fdt = fdp->fd_files; 2601#ifdef CAPABILITIES 2602 if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) 2603#else 2604 if (fp == fdt->fdt_ofiles[fd].fde_file) 2605#endif 2606 break; 2607 fdrop(fp, curthread); 2608 } 2609 *fpp = fp; 2610 if (seqp != NULL) { 2611#ifdef CAPABILITIES 2612 *seqp = seq; 2613#endif 2614 } 2615 return (0); 2616} 2617 2618/* 2619 * Extract the file pointer associated with the specified descriptor for the 2620 * current user process. 2621 * 2622 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2623 * returned. 2624 * 2625 * File's rights will be checked against the capability rights mask. 2626 * 2627 * If an error occurred the non-zero error is returned and *fpp is set to 2628 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2629 * responsible for fdrop(). 2630 */ 2631static __inline int 2632_fget(struct thread *td, int fd, struct file **fpp, int flags, 2633 cap_rights_t *needrightsp, seq_t *seqp) 2634{ 2635 struct filedesc *fdp; 2636 struct file *fp; 2637 int error; 2638 2639 *fpp = NULL; 2640 fdp = td->td_proc->p_fd; 2641 error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); 2642 if (error != 0) 2643 return (error); 2644 if (fp->f_ops == &badfileops) { 2645 fdrop(fp, td); 2646 return (EBADF); 2647 } 2648 2649 /* 2650 * FREAD and FWRITE failure return EBADF as per POSIX. 2651 */ 2652 error = 0; 2653 switch (flags) { 2654 case FREAD: 2655 case FWRITE: 2656 if ((fp->f_flag & flags) == 0) 2657 error = EBADF; 2658 break; 2659 case FEXEC: 2660 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2661 ((fp->f_flag & FWRITE) != 0)) 2662 error = EBADF; 2663 break; 2664 case 0: 2665 break; 2666 default: 2667 KASSERT(0, ("wrong flags")); 2668 } 2669 2670 if (error != 0) { 2671 fdrop(fp, td); 2672 return (error); 2673 } 2674 2675 *fpp = fp; 2676 return (0); 2677} 2678 2679int 2680fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2681{ 2682 2683 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2684} 2685 2686int 2687fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 2688 struct file **fpp) 2689{ 2690 int error; 2691#ifndef CAPABILITIES 2692 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2693 if (maxprotp != NULL) 2694 *maxprotp = VM_PROT_ALL; 2695#else 2696 cap_rights_t fdrights; 2697 struct filedesc *fdp = td->td_proc->p_fd; 2698 seq_t seq; 2699 2700 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2701 for (;;) { 2702 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2703 if (error != 0) 2704 return (error); 2705 if (maxprotp != NULL) 2706 fdrights = *cap_rights(fdp, fd); 2707 if (!fd_modified(fdp, fd, seq)) 2708 break; 2709 fdrop(*fpp, td); 2710 } 2711 2712 /* 2713 * If requested, convert capability rights to access flags. 2714 */ 2715 if (maxprotp != NULL) 2716 *maxprotp = cap_rights_to_vmprot(&fdrights); 2717#endif 2718 return (error); 2719} 2720 2721int 2722fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2723{ 2724 2725 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2726} 2727 2728int 2729fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2730{ 2731 2732 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2733} 2734 2735int 2736fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2737 struct file **fpp) 2738{ 2739 struct filedesc *fdp = td->td_proc->p_fd; 2740#ifndef CAPABILITIES 2741 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2742#else 2743 int error; 2744 seq_t seq; 2745 2746 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2747 for (;;) { 2748 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2749 if (error != 0) 2750 return (error); 2751 error = cap_fcntl_check(fdp, fd, needfcntl); 2752 if (!fd_modified(fdp, fd, seq)) 2753 break; 2754 fdrop(*fpp, td); 2755 } 2756 if (error != 0) { 2757 fdrop(*fpp, td); 2758 *fpp = NULL; 2759 } 2760 return (error); 2761#endif 2762} 2763 2764/* 2765 * Like fget() but loads the underlying vnode, or returns an error if the 2766 * descriptor does not represent a vnode. Note that pipes use vnodes but 2767 * never have VM objects. The returned vnode will be vref()'d. 2768 * 2769 * XXX: what about the unused flags ? 2770 */ 2771static __inline int 2772_fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2773 struct vnode **vpp) 2774{ 2775 struct file *fp; 2776 int error; 2777 2778 *vpp = NULL; 2779 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2780 if (error != 0) 2781 return (error); 2782 if (fp->f_vnode == NULL) { 2783 error = EINVAL; 2784 } else { 2785 *vpp = fp->f_vnode; 2786 vrefact(*vpp); 2787 } 2788 fdrop(fp, td); 2789 2790 return (error); 2791} 2792 2793int 2794fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2795{ 2796 2797 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2798} 2799 2800int 2801fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2802 struct filecaps *havecaps, struct vnode **vpp) 2803{ 2804 struct filedesc *fdp; 2805 struct filecaps caps; 2806 struct file *fp; 2807 int error; 2808 2809 fdp = td->td_proc->p_fd; 2810 error = fget_cap_locked(fdp, fd, needrightsp, &fp, &caps); 2811 if (error != 0) 2812 return (error); 2813 if (fp->f_ops == &badfileops) { 2814 error = EBADF; 2815 goto out; 2816 } 2817 if (fp->f_vnode == NULL) { 2818 error = EINVAL; 2819 goto out; 2820 } 2821 2822 *havecaps = caps; 2823 *vpp = fp->f_vnode; 2824 vrefact(*vpp); 2825 2826 return (0); 2827out: 2828 filecaps_free(&caps); 2829 return (error); 2830} 2831 2832int 2833fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2834{ 2835 2836 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2837} 2838 2839int 2840fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2841{ 2842 2843 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2844} 2845 2846#ifdef notyet 2847int 2848fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2849 struct vnode **vpp) 2850{ 2851 2852 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2853} 2854#endif 2855 2856/* 2857 * Handle the last reference to a file being closed. 2858 */ 2859int 2860_fdrop(struct file *fp, struct thread *td) 2861{ 2862 int error; 2863 2864 if (fp->f_count != 0) 2865 panic("fdrop: count %d", fp->f_count); 2866 error = fo_close(fp, td); 2867 atomic_subtract_int(&openfiles, 1); 2868 crfree(fp->f_cred); 2869 free(fp->f_advice, M_FADVISE); 2870 uma_zfree(file_zone, fp); 2871 2872 return (error); 2873} 2874 2875/* 2876 * Apply an advisory lock on a file descriptor. 2877 * 2878 * Just attempt to get a record lock of the requested type on the entire file 2879 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2880 */ 2881#ifndef _SYS_SYSPROTO_H_ 2882struct flock_args { 2883 int fd; 2884 int how; 2885}; 2886#endif 2887/* ARGSUSED */ 2888int 2889sys_flock(struct thread *td, struct flock_args *uap) 2890{ 2891 struct file *fp; 2892 struct vnode *vp; 2893 struct flock lf; 2894 cap_rights_t rights; 2895 int error; 2896 2897 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2898 if (error != 0) 2899 return (error); 2900 if (fp->f_type != DTYPE_VNODE) { 2901 fdrop(fp, td); 2902 return (EOPNOTSUPP); 2903 } 2904 2905 vp = fp->f_vnode; 2906 lf.l_whence = SEEK_SET; 2907 lf.l_start = 0; 2908 lf.l_len = 0; 2909 if (uap->how & LOCK_UN) { 2910 lf.l_type = F_UNLCK; 2911 atomic_clear_int(&fp->f_flag, FHASLOCK); 2912 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2913 goto done2; 2914 } 2915 if (uap->how & LOCK_EX) 2916 lf.l_type = F_WRLCK; 2917 else if (uap->how & LOCK_SH) 2918 lf.l_type = F_RDLCK; 2919 else { 2920 error = EBADF; 2921 goto done2; 2922 } 2923 atomic_set_int(&fp->f_flag, FHASLOCK); 2924 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2925 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2926done2: 2927 fdrop(fp, td); 2928 return (error); 2929} 2930/* 2931 * Duplicate the specified descriptor to a free descriptor. 2932 */ 2933int 2934dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2935 int openerror, int *indxp) 2936{ 2937 struct filedescent *newfde, *oldfde; 2938 struct file *fp; 2939 int error, indx; 2940 2941 KASSERT(openerror == ENODEV || openerror == ENXIO, 2942 ("unexpected error %d in %s", openerror, __func__)); 2943 2944 /* 2945 * If the to-be-dup'd fd number is greater than the allowed number 2946 * of file descriptors, or the fd to be dup'd has already been 2947 * closed, then reject. 2948 */ 2949 FILEDESC_XLOCK(fdp); 2950 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2951 FILEDESC_XUNLOCK(fdp); 2952 return (EBADF); 2953 } 2954 2955 error = fdalloc(td, 0, &indx); 2956 if (error != 0) { 2957 FILEDESC_XUNLOCK(fdp); 2958 return (error); 2959 } 2960 2961 /* 2962 * There are two cases of interest here. 2963 * 2964 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2965 * 2966 * For ENXIO steal away the file structure from (dfd) and store it in 2967 * (indx). (dfd) is effectively closed by this operation. 2968 */ 2969 switch (openerror) { 2970 case ENODEV: 2971 /* 2972 * Check that the mode the file is being opened for is a 2973 * subset of the mode of the existing descriptor. 2974 */ 2975 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2976 fdunused(fdp, indx); 2977 FILEDESC_XUNLOCK(fdp); 2978 return (EACCES); 2979 } 2980 fhold(fp); 2981 newfde = &fdp->fd_ofiles[indx]; 2982 oldfde = &fdp->fd_ofiles[dfd]; 2983#ifdef CAPABILITIES 2984 seq_write_begin(&newfde->fde_seq); 2985#endif 2986 memcpy(newfde, oldfde, fde_change_size); 2987 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps, true); 2988#ifdef CAPABILITIES 2989 seq_write_end(&newfde->fde_seq); 2990#endif 2991 break; 2992 case ENXIO: 2993 /* 2994 * Steal away the file pointer from dfd and stuff it into indx. 2995 */ 2996 newfde = &fdp->fd_ofiles[indx]; 2997 oldfde = &fdp->fd_ofiles[dfd]; 2998#ifdef CAPABILITIES 2999 seq_write_begin(&newfde->fde_seq); 3000#endif 3001 memcpy(newfde, oldfde, fde_change_size); 3002 oldfde->fde_file = NULL; 3003 fdunused(fdp, dfd); 3004#ifdef CAPABILITIES 3005 seq_write_end(&newfde->fde_seq); 3006#endif 3007 break; 3008 } 3009 FILEDESC_XUNLOCK(fdp); 3010 *indxp = indx; 3011 return (0); 3012} 3013 3014/* 3015 * This sysctl determines if we will allow a process to chroot(2) if it 3016 * has a directory open: 3017 * 0: disallowed for all processes. 3018 * 1: allowed for processes that were not already chroot(2)'ed. 3019 * 2: allowed for all processes. 3020 */ 3021 3022static int chroot_allow_open_directories = 1; 3023 3024SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3025 &chroot_allow_open_directories, 0, 3026 "Allow a process to chroot(2) if it has a directory open"); 3027 3028/* 3029 * Helper function for raised chroot(2) security function: Refuse if 3030 * any filedescriptors are open directories. 3031 */ 3032static int 3033chroot_refuse_vdir_fds(struct filedesc *fdp) 3034{ 3035 struct vnode *vp; 3036 struct file *fp; 3037 int fd; 3038 3039 FILEDESC_LOCK_ASSERT(fdp); 3040 3041 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3042 fp = fget_locked(fdp, fd); 3043 if (fp == NULL) 3044 continue; 3045 if (fp->f_type == DTYPE_VNODE) { 3046 vp = fp->f_vnode; 3047 if (vp->v_type == VDIR) 3048 return (EPERM); 3049 } 3050 } 3051 return (0); 3052} 3053 3054/* 3055* The caller is responsible for invoking priv_check() and 3056* mac_vnode_check_chroot() to authorize this operation. 3057*/ 3058int 3059pwd_chroot(struct thread *td, struct vnode *vp) 3060{ 3061 struct filedesc *fdp; 3062 struct vnode *oldvp; 3063 int error; 3064 3065 fdp = td->td_proc->p_fd; 3066 FILEDESC_XLOCK(fdp); 3067 if (chroot_allow_open_directories == 0 || 3068 (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) { 3069 error = chroot_refuse_vdir_fds(fdp); 3070 if (error != 0) { 3071 FILEDESC_XUNLOCK(fdp); 3072 return (error); 3073 } 3074 } 3075 oldvp = fdp->fd_rdir; 3076 vrefact(vp); 3077 fdp->fd_rdir = vp; 3078 if (fdp->fd_jdir == NULL) { 3079 vrefact(vp); 3080 fdp->fd_jdir = vp; 3081 } 3082 FILEDESC_XUNLOCK(fdp); 3083 vrele(oldvp); 3084 return (0); 3085} 3086 3087void 3088pwd_chdir(struct thread *td, struct vnode *vp) 3089{ 3090 struct filedesc *fdp; 3091 struct vnode *oldvp; 3092 3093 fdp = td->td_proc->p_fd; 3094 FILEDESC_XLOCK(fdp); 3095 VNASSERT(vp->v_usecount > 0, vp, 3096 ("chdir to a vnode with zero usecount")); 3097 oldvp = fdp->fd_cdir; 3098 fdp->fd_cdir = vp; 3099 FILEDESC_XUNLOCK(fdp); 3100 vrele(oldvp); 3101} 3102 3103/* 3104 * jail_attach(2) changes both root and working directories. 3105 */ 3106int 3107pwd_chroot_chdir(struct thread *td, struct vnode *vp) 3108{ 3109 struct filedesc *fdp; 3110 struct vnode *oldvrp, *oldvcp; 3111 int error; 3112 3113 fdp = td->td_proc->p_fd; 3114 FILEDESC_XLOCK(fdp); 3115 error = chroot_refuse_vdir_fds(fdp); 3116 if (error != 0) { 3117 FILEDESC_XUNLOCK(fdp); 3118 return (error); 3119 } 3120 oldvrp = fdp->fd_rdir; 3121 vrefact(vp); 3122 fdp->fd_rdir = vp; 3123 oldvcp = fdp->fd_cdir; 3124 vrefact(vp); 3125 fdp->fd_cdir = vp; 3126 if (fdp->fd_jdir == NULL) { 3127 vrefact(vp); 3128 fdp->fd_jdir = vp; 3129 } 3130 FILEDESC_XUNLOCK(fdp); 3131 vrele(oldvrp); 3132 vrele(oldvcp); 3133 return (0); 3134} 3135 3136/* 3137 * Scan all active processes and prisons to see if any of them have a current 3138 * or root directory of `olddp'. If so, replace them with the new mount point. 3139 */ 3140void 3141mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3142{ 3143 struct filedesc *fdp; 3144 struct prison *pr; 3145 struct proc *p; 3146 int nrele; 3147 3148 if (vrefcnt(olddp) == 1) 3149 return; 3150 nrele = 0; 3151 sx_slock(&allproc_lock); 3152 FOREACH_PROC_IN_SYSTEM(p) { 3153 PROC_LOCK(p); 3154 fdp = fdhold(p); 3155 PROC_UNLOCK(p); 3156 if (fdp == NULL) 3157 continue; 3158 FILEDESC_XLOCK(fdp); 3159 if (fdp->fd_cdir == olddp) { 3160 vrefact(newdp); 3161 fdp->fd_cdir = newdp; 3162 nrele++; 3163 } 3164 if (fdp->fd_rdir == olddp) { 3165 vrefact(newdp); 3166 fdp->fd_rdir = newdp; 3167 nrele++; 3168 } 3169 if (fdp->fd_jdir == olddp) { 3170 vrefact(newdp); 3171 fdp->fd_jdir = newdp; 3172 nrele++; 3173 } 3174 FILEDESC_XUNLOCK(fdp); 3175 fddrop(fdp); 3176 } 3177 sx_sunlock(&allproc_lock); 3178 if (rootvnode == olddp) { 3179 vrefact(newdp); 3180 rootvnode = newdp; 3181 nrele++; 3182 } 3183 mtx_lock(&prison0.pr_mtx); 3184 if (prison0.pr_root == olddp) { 3185 vrefact(newdp); 3186 prison0.pr_root = newdp; 3187 nrele++; 3188 } 3189 mtx_unlock(&prison0.pr_mtx); 3190 sx_slock(&allprison_lock); 3191 TAILQ_FOREACH(pr, &allprison, pr_list) { 3192 mtx_lock(&pr->pr_mtx); 3193 if (pr->pr_root == olddp) { 3194 vrefact(newdp); 3195 pr->pr_root = newdp; 3196 nrele++; 3197 } 3198 mtx_unlock(&pr->pr_mtx); 3199 } 3200 sx_sunlock(&allprison_lock); 3201 while (nrele--) 3202 vrele(olddp); 3203} 3204 3205struct filedesc_to_leader * 3206filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3207{ 3208 struct filedesc_to_leader *fdtol; 3209 3210 fdtol = malloc(sizeof(struct filedesc_to_leader), 3211 M_FILEDESC_TO_LEADER, M_WAITOK); 3212 fdtol->fdl_refcount = 1; 3213 fdtol->fdl_holdcount = 0; 3214 fdtol->fdl_wakeup = 0; 3215 fdtol->fdl_leader = leader; 3216 if (old != NULL) { 3217 FILEDESC_XLOCK(fdp); 3218 fdtol->fdl_next = old->fdl_next; 3219 fdtol->fdl_prev = old; 3220 old->fdl_next = fdtol; 3221 fdtol->fdl_next->fdl_prev = fdtol; 3222 FILEDESC_XUNLOCK(fdp); 3223 } else { 3224 fdtol->fdl_next = fdtol; 3225 fdtol->fdl_prev = fdtol; 3226 } 3227 return (fdtol); 3228} 3229 3230static int 3231sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3232{ 3233 struct filedesc *fdp; 3234 int i, count, slots; 3235 3236 if (*(int *)arg1 != 0) 3237 return (EINVAL); 3238 3239 fdp = curproc->p_fd; 3240 count = 0; 3241 FILEDESC_SLOCK(fdp); 3242 slots = NDSLOTS(fdp->fd_lastfile + 1); 3243 for (i = 0; i < slots; i++) 3244 count += bitcountl(fdp->fd_map[i]); 3245 FILEDESC_SUNLOCK(fdp); 3246 3247 return (SYSCTL_OUT(req, &count, sizeof(count))); 3248} 3249 3250static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3251 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3252 "Number of open file descriptors"); 3253 3254/* 3255 * Get file structures globally. 3256 */ 3257static int 3258sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3259{ 3260 struct xfile xf; 3261 struct filedesc *fdp; 3262 struct file *fp; 3263 struct proc *p; 3264 int error, n; 3265 3266 error = sysctl_wire_old_buffer(req, 0); 3267 if (error != 0) 3268 return (error); 3269 if (req->oldptr == NULL) { 3270 n = 0; 3271 sx_slock(&allproc_lock); 3272 FOREACH_PROC_IN_SYSTEM(p) { 3273 PROC_LOCK(p); 3274 if (p->p_state == PRS_NEW) { 3275 PROC_UNLOCK(p); 3276 continue; 3277 } 3278 fdp = fdhold(p); 3279 PROC_UNLOCK(p); 3280 if (fdp == NULL) 3281 continue; 3282 /* overestimates sparse tables. */ 3283 if (fdp->fd_lastfile > 0) 3284 n += fdp->fd_lastfile; 3285 fddrop(fdp); 3286 } 3287 sx_sunlock(&allproc_lock); 3288 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3289 } 3290 error = 0; 3291 bzero(&xf, sizeof(xf)); 3292 xf.xf_size = sizeof(xf); 3293 sx_slock(&allproc_lock); 3294 FOREACH_PROC_IN_SYSTEM(p) { 3295 PROC_LOCK(p); 3296 if (p->p_state == PRS_NEW) { 3297 PROC_UNLOCK(p); 3298 continue; 3299 } 3300 if (p_cansee(req->td, p) != 0) { 3301 PROC_UNLOCK(p); 3302 continue; 3303 } 3304 xf.xf_pid = p->p_pid; 3305 xf.xf_uid = p->p_ucred->cr_uid; 3306 fdp = fdhold(p); 3307 PROC_UNLOCK(p); 3308 if (fdp == NULL) 3309 continue; 3310 FILEDESC_SLOCK(fdp); 3311 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3312 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3313 continue; 3314 xf.xf_fd = n; 3315 xf.xf_file = fp; 3316 xf.xf_data = fp->f_data; 3317 xf.xf_vnode = fp->f_vnode; 3318 xf.xf_type = fp->f_type; 3319 xf.xf_count = fp->f_count; 3320 xf.xf_msgcount = 0; 3321 xf.xf_offset = foffset_get(fp); 3322 xf.xf_flag = fp->f_flag; 3323 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3324 if (error) 3325 break; 3326 } 3327 FILEDESC_SUNLOCK(fdp); 3328 fddrop(fdp); 3329 if (error) 3330 break; 3331 } 3332 sx_sunlock(&allproc_lock); 3333 return (error); 3334} 3335 3336SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3337 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3338 3339#ifdef KINFO_FILE_SIZE 3340CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3341#endif 3342 3343static int 3344xlate_fflags(int fflags) 3345{ 3346 static const struct { 3347 int fflag; 3348 int kf_fflag; 3349 } fflags_table[] = { 3350 { FAPPEND, KF_FLAG_APPEND }, 3351 { FASYNC, KF_FLAG_ASYNC }, 3352 { FFSYNC, KF_FLAG_FSYNC }, 3353 { FHASLOCK, KF_FLAG_HASLOCK }, 3354 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3355 { FREAD, KF_FLAG_READ }, 3356 { FWRITE, KF_FLAG_WRITE }, 3357 { O_CREAT, KF_FLAG_CREAT }, 3358 { O_DIRECT, KF_FLAG_DIRECT }, 3359 { O_EXCL, KF_FLAG_EXCL }, 3360 { O_EXEC, KF_FLAG_EXEC }, 3361 { O_EXLOCK, KF_FLAG_EXLOCK }, 3362 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3363 { O_SHLOCK, KF_FLAG_SHLOCK }, 3364 { O_TRUNC, KF_FLAG_TRUNC } 3365 }; 3366 unsigned int i; 3367 int kflags; 3368 3369 kflags = 0; 3370 for (i = 0; i < nitems(fflags_table); i++) 3371 if (fflags & fflags_table[i].fflag) 3372 kflags |= fflags_table[i].kf_fflag; 3373 return (kflags); 3374} 3375 3376/* Trim unused data from kf_path by truncating the structure size. */ 3377static void 3378pack_kinfo(struct kinfo_file *kif) 3379{ 3380 3381 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3382 strlen(kif->kf_path) + 1; 3383 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3384} 3385 3386static void 3387export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3388 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3389{ 3390 int error; 3391 3392 bzero(kif, sizeof(*kif)); 3393 3394 /* Set a default type to allow for empty fill_kinfo() methods. */ 3395 kif->kf_type = KF_TYPE_UNKNOWN; 3396 kif->kf_flags = xlate_fflags(fp->f_flag); 3397 if (rightsp != NULL) 3398 kif->kf_cap_rights = *rightsp; 3399 else 3400 cap_rights_init(&kif->kf_cap_rights); 3401 kif->kf_fd = fd; 3402 kif->kf_ref_count = fp->f_count; 3403 kif->kf_offset = foffset_get(fp); 3404 3405 /* 3406 * This may drop the filedesc lock, so the 'fp' cannot be 3407 * accessed after this call. 3408 */ 3409 error = fo_fill_kinfo(fp, kif, fdp); 3410 if (error == 0) 3411 kif->kf_status |= KF_ATTR_VALID; 3412 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3413 pack_kinfo(kif); 3414 else 3415 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3416} 3417 3418static void 3419export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3420 struct kinfo_file *kif, int flags) 3421{ 3422 int error; 3423 3424 bzero(kif, sizeof(*kif)); 3425 3426 kif->kf_type = KF_TYPE_VNODE; 3427 error = vn_fill_kinfo_vnode(vp, kif); 3428 if (error == 0) 3429 kif->kf_status |= KF_ATTR_VALID; 3430 kif->kf_flags = xlate_fflags(fflags); 3431 cap_rights_init(&kif->kf_cap_rights); 3432 kif->kf_fd = fd; 3433 kif->kf_ref_count = -1; 3434 kif->kf_offset = -1; 3435 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3436 pack_kinfo(kif); 3437 else 3438 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3439 vrele(vp); 3440} 3441 3442struct export_fd_buf { 3443 struct filedesc *fdp; 3444 struct sbuf *sb; 3445 ssize_t remainder; 3446 struct kinfo_file kif; 3447 int flags; 3448}; 3449 3450static int 3451export_kinfo_to_sb(struct export_fd_buf *efbuf) 3452{ 3453 struct kinfo_file *kif; 3454 3455 kif = &efbuf->kif; 3456 if (efbuf->remainder != -1) { 3457 if (efbuf->remainder < kif->kf_structsize) { 3458 /* Terminate export. */ 3459 efbuf->remainder = 0; 3460 return (0); 3461 } 3462 efbuf->remainder -= kif->kf_structsize; 3463 } 3464 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3465} 3466 3467static int 3468export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3469 struct export_fd_buf *efbuf) 3470{ 3471 int error; 3472 3473 if (efbuf->remainder == 0) 3474 return (0); 3475 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3476 efbuf->flags); 3477 FILEDESC_SUNLOCK(efbuf->fdp); 3478 error = export_kinfo_to_sb(efbuf); 3479 FILEDESC_SLOCK(efbuf->fdp); 3480 return (error); 3481} 3482 3483static int 3484export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3485 struct export_fd_buf *efbuf) 3486{ 3487 int error; 3488 3489 if (efbuf->remainder == 0) 3490 return (0); 3491 if (efbuf->fdp != NULL) 3492 FILEDESC_SUNLOCK(efbuf->fdp); 3493 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3494 error = export_kinfo_to_sb(efbuf); 3495 if (efbuf->fdp != NULL) 3496 FILEDESC_SLOCK(efbuf->fdp); 3497 return (error); 3498} 3499 3500/* 3501 * Store a process file descriptor information to sbuf. 3502 * 3503 * Takes a locked proc as argument, and returns with the proc unlocked. 3504 */ 3505int 3506kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3507 int flags) 3508{ 3509 struct file *fp; 3510 struct filedesc *fdp; 3511 struct export_fd_buf *efbuf; 3512 struct vnode *cttyvp, *textvp, *tracevp; 3513 int error, i; 3514 cap_rights_t rights; 3515 3516 PROC_LOCK_ASSERT(p, MA_OWNED); 3517 3518 /* ktrace vnode */ 3519 tracevp = p->p_tracevp; 3520 if (tracevp != NULL) 3521 vrefact(tracevp); 3522 /* text vnode */ 3523 textvp = p->p_textvp; 3524 if (textvp != NULL) 3525 vrefact(textvp); 3526 /* Controlling tty. */ 3527 cttyvp = NULL; 3528 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3529 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3530 if (cttyvp != NULL) 3531 vrefact(cttyvp); 3532 } 3533 fdp = fdhold(p); 3534 PROC_UNLOCK(p); 3535 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3536 efbuf->fdp = NULL; 3537 efbuf->sb = sb; 3538 efbuf->remainder = maxlen; 3539 efbuf->flags = flags; 3540 if (tracevp != NULL) 3541 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3542 efbuf); 3543 if (textvp != NULL) 3544 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3545 if (cttyvp != NULL) 3546 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3547 efbuf); 3548 error = 0; 3549 if (fdp == NULL) 3550 goto fail; 3551 efbuf->fdp = fdp; 3552 FILEDESC_SLOCK(fdp); 3553 /* working directory */ 3554 if (fdp->fd_cdir != NULL) { 3555 vrefact(fdp->fd_cdir); 3556 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3557 } 3558 /* root directory */ 3559 if (fdp->fd_rdir != NULL) { 3560 vrefact(fdp->fd_rdir); 3561 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3562 } 3563 /* jail directory */ 3564 if (fdp->fd_jdir != NULL) { 3565 vrefact(fdp->fd_jdir); 3566 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3567 } 3568 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3569 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3570 continue; 3571#ifdef CAPABILITIES 3572 rights = *cap_rights(fdp, i); 3573#else /* !CAPABILITIES */ 3574 cap_rights_init(&rights); 3575#endif 3576 /* 3577 * Create sysctl entry. It is OK to drop the filedesc 3578 * lock inside of export_file_to_sb() as we will 3579 * re-validate and re-evaluate its properties when the 3580 * loop continues. 3581 */ 3582 error = export_file_to_sb(fp, i, &rights, efbuf); 3583 if (error != 0 || efbuf->remainder == 0) 3584 break; 3585 } 3586 FILEDESC_SUNLOCK(fdp); 3587 fddrop(fdp); 3588fail: 3589 free(efbuf, M_TEMP); 3590 return (error); 3591} 3592 3593#define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3594 3595/* 3596 * Get per-process file descriptors for use by procstat(1), et al. 3597 */ 3598static int 3599sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3600{ 3601 struct sbuf sb; 3602 struct proc *p; 3603 ssize_t maxlen; 3604 int error, error2, *name; 3605 3606 name = (int *)arg1; 3607 3608 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3609 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3610 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3611 if (error != 0) { 3612 sbuf_delete(&sb); 3613 return (error); 3614 } 3615 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3616 error = kern_proc_filedesc_out(p, &sb, maxlen, 3617 KERN_FILEDESC_PACK_KINFO); 3618 error2 = sbuf_finish(&sb); 3619 sbuf_delete(&sb); 3620 return (error != 0 ? error : error2); 3621} 3622 3623#ifdef KINFO_OFILE_SIZE 3624CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3625#endif 3626 3627#ifdef COMPAT_FREEBSD7 3628static void 3629kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3630{ 3631 3632 okif->kf_structsize = sizeof(*okif); 3633 okif->kf_type = kif->kf_type; 3634 okif->kf_fd = kif->kf_fd; 3635 okif->kf_ref_count = kif->kf_ref_count; 3636 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3637 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3638 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3639 okif->kf_offset = kif->kf_offset; 3640 okif->kf_vnode_type = kif->kf_vnode_type; 3641 okif->kf_sock_domain = kif->kf_sock_domain; 3642 okif->kf_sock_type = kif->kf_sock_type; 3643 okif->kf_sock_protocol = kif->kf_sock_protocol; 3644 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3645 okif->kf_sa_local = kif->kf_sa_local; 3646 okif->kf_sa_peer = kif->kf_sa_peer; 3647} 3648 3649static int 3650export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3651 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3652{ 3653 int error; 3654 3655 vrefact(vp); 3656 FILEDESC_SUNLOCK(fdp); 3657 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 3658 kinfo_to_okinfo(kif, okif); 3659 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3660 FILEDESC_SLOCK(fdp); 3661 return (error); 3662} 3663 3664/* 3665 * Get per-process file descriptors for use by procstat(1), et al. 3666 */ 3667static int 3668sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3669{ 3670 struct kinfo_ofile *okif; 3671 struct kinfo_file *kif; 3672 struct filedesc *fdp; 3673 int error, i, *name; 3674 struct file *fp; 3675 struct proc *p; 3676 3677 name = (int *)arg1; 3678 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3679 if (error != 0) 3680 return (error); 3681 fdp = fdhold(p); 3682 PROC_UNLOCK(p); 3683 if (fdp == NULL) 3684 return (ENOENT); 3685 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3686 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3687 FILEDESC_SLOCK(fdp); 3688 if (fdp->fd_cdir != NULL) 3689 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3690 okif, fdp, req); 3691 if (fdp->fd_rdir != NULL) 3692 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3693 okif, fdp, req); 3694 if (fdp->fd_jdir != NULL) 3695 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3696 okif, fdp, req); 3697 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3698 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3699 continue; 3700 export_file_to_kinfo(fp, i, NULL, kif, fdp, 3701 KERN_FILEDESC_PACK_KINFO); 3702 FILEDESC_SUNLOCK(fdp); 3703 kinfo_to_okinfo(kif, okif); 3704 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3705 FILEDESC_SLOCK(fdp); 3706 if (error) 3707 break; 3708 } 3709 FILEDESC_SUNLOCK(fdp); 3710 fddrop(fdp); 3711 free(kif, M_TEMP); 3712 free(okif, M_TEMP); 3713 return (0); 3714} 3715 3716static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3717 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3718 "Process ofiledesc entries"); 3719#endif /* COMPAT_FREEBSD7 */ 3720 3721int 3722vntype_to_kinfo(int vtype) 3723{ 3724 struct { 3725 int vtype; 3726 int kf_vtype; 3727 } vtypes_table[] = { 3728 { VBAD, KF_VTYPE_VBAD }, 3729 { VBLK, KF_VTYPE_VBLK }, 3730 { VCHR, KF_VTYPE_VCHR }, 3731 { VDIR, KF_VTYPE_VDIR }, 3732 { VFIFO, KF_VTYPE_VFIFO }, 3733 { VLNK, KF_VTYPE_VLNK }, 3734 { VNON, KF_VTYPE_VNON }, 3735 { VREG, KF_VTYPE_VREG }, 3736 { VSOCK, KF_VTYPE_VSOCK } 3737 }; 3738 unsigned int i; 3739 3740 /* 3741 * Perform vtype translation. 3742 */ 3743 for (i = 0; i < nitems(vtypes_table); i++) 3744 if (vtypes_table[i].vtype == vtype) 3745 return (vtypes_table[i].kf_vtype); 3746 3747 return (KF_VTYPE_UNKNOWN); 3748} 3749 3750static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3751 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3752 "Process filedesc entries"); 3753 3754/* 3755 * Store a process current working directory information to sbuf. 3756 * 3757 * Takes a locked proc as argument, and returns with the proc unlocked. 3758 */ 3759int 3760kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3761{ 3762 struct filedesc *fdp; 3763 struct export_fd_buf *efbuf; 3764 int error; 3765 3766 PROC_LOCK_ASSERT(p, MA_OWNED); 3767 3768 fdp = fdhold(p); 3769 PROC_UNLOCK(p); 3770 if (fdp == NULL) 3771 return (EINVAL); 3772 3773 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3774 efbuf->fdp = fdp; 3775 efbuf->sb = sb; 3776 efbuf->remainder = maxlen; 3777 3778 FILEDESC_SLOCK(fdp); 3779 if (fdp->fd_cdir == NULL) 3780 error = EINVAL; 3781 else { 3782 vrefact(fdp->fd_cdir); 3783 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3784 FREAD, efbuf); 3785 } 3786 FILEDESC_SUNLOCK(fdp); 3787 fddrop(fdp); 3788 free(efbuf, M_TEMP); 3789 return (error); 3790} 3791 3792/* 3793 * Get per-process current working directory. 3794 */ 3795static int 3796sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3797{ 3798 struct sbuf sb; 3799 struct proc *p; 3800 ssize_t maxlen; 3801 int error, error2, *name; 3802 3803 name = (int *)arg1; 3804 3805 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3806 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3807 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3808 if (error != 0) { 3809 sbuf_delete(&sb); 3810 return (error); 3811 } 3812 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3813 error = kern_proc_cwd_out(p, &sb, maxlen); 3814 error2 = sbuf_finish(&sb); 3815 sbuf_delete(&sb); 3816 return (error != 0 ? error : error2); 3817} 3818 3819static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3820 sysctl_kern_proc_cwd, "Process current working directory"); 3821 3822#ifdef DDB 3823/* 3824 * For the purposes of debugging, generate a human-readable string for the 3825 * file type. 3826 */ 3827static const char * 3828file_type_to_name(short type) 3829{ 3830 3831 switch (type) { 3832 case 0: 3833 return ("zero"); 3834 case DTYPE_VNODE: 3835 return ("vnod"); 3836 case DTYPE_SOCKET: 3837 return ("sock"); 3838 case DTYPE_PIPE: 3839 return ("pipe"); 3840 case DTYPE_FIFO: 3841 return ("fifo"); 3842 case DTYPE_KQUEUE: 3843 return ("kque"); 3844 case DTYPE_CRYPTO: 3845 return ("crpt"); 3846 case DTYPE_MQUEUE: 3847 return ("mque"); 3848 case DTYPE_SHM: 3849 return ("shm"); 3850 case DTYPE_SEM: 3851 return ("ksem"); 3852 default: 3853 return ("unkn"); 3854 } 3855} 3856 3857/* 3858 * For the purposes of debugging, identify a process (if any, perhaps one of 3859 * many) that references the passed file in its file descriptor array. Return 3860 * NULL if none. 3861 */ 3862static struct proc * 3863file_to_first_proc(struct file *fp) 3864{ 3865 struct filedesc *fdp; 3866 struct proc *p; 3867 int n; 3868 3869 FOREACH_PROC_IN_SYSTEM(p) { 3870 if (p->p_state == PRS_NEW) 3871 continue; 3872 fdp = p->p_fd; 3873 if (fdp == NULL) 3874 continue; 3875 for (n = 0; n <= fdp->fd_lastfile; n++) { 3876 if (fp == fdp->fd_ofiles[n].fde_file) 3877 return (p); 3878 } 3879 } 3880 return (NULL); 3881} 3882 3883static void 3884db_print_file(struct file *fp, int header) 3885{ 3886 struct proc *p; 3887 3888 if (header) 3889 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3890 "File", "Type", "Data", "Flag", "GCFl", "Count", 3891 "MCount", "Vnode", "FPID", "FCmd"); 3892 p = file_to_first_proc(fp); 3893 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3894 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3895 0, fp->f_count, 0, fp->f_vnode, 3896 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3897} 3898 3899DB_SHOW_COMMAND(file, db_show_file) 3900{ 3901 struct file *fp; 3902 3903 if (!have_addr) { 3904 db_printf("usage: show file <addr>\n"); 3905 return; 3906 } 3907 fp = (struct file *)addr; 3908 db_print_file(fp, 1); 3909} 3910 3911DB_SHOW_COMMAND(files, db_show_files) 3912{ 3913 struct filedesc *fdp; 3914 struct file *fp; 3915 struct proc *p; 3916 int header; 3917 int n; 3918 3919 header = 1; 3920 FOREACH_PROC_IN_SYSTEM(p) { 3921 if (p->p_state == PRS_NEW) 3922 continue; 3923 if ((fdp = p->p_fd) == NULL) 3924 continue; 3925 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3926 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3927 continue; 3928 db_print_file(fp, header); 3929 header = 0; 3930 } 3931 } 3932} 3933#endif 3934 3935SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3936 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3937 3938SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3939 &maxfiles, 0, "Maximum number of files"); 3940 3941SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3942 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3943 3944/* ARGSUSED*/ 3945static void 3946filelistinit(void *dummy) 3947{ 3948 3949 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3950 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3951 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 3952 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 3953 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3954} 3955SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3956 3957/*-------------------------------------------------------------------*/ 3958 3959static int 3960badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3961 int flags, struct thread *td) 3962{ 3963 3964 return (EBADF); 3965} 3966 3967static int 3968badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3969 struct thread *td) 3970{ 3971 3972 return (EINVAL); 3973} 3974 3975static int 3976badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3977 struct thread *td) 3978{ 3979 3980 return (EBADF); 3981} 3982 3983static int 3984badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3985 struct thread *td) 3986{ 3987 3988 return (0); 3989} 3990 3991static int 3992badfo_kqfilter(struct file *fp, struct knote *kn) 3993{ 3994 3995 return (EBADF); 3996} 3997 3998static int 3999badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4000 struct thread *td) 4001{ 4002 4003 return (EBADF); 4004} 4005 4006static int 4007badfo_close(struct file *fp, struct thread *td) 4008{ 4009 4010 return (0); 4011} 4012 4013static int 4014badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4015 struct thread *td) 4016{ 4017 4018 return (EBADF); 4019} 4020 4021static int 4022badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4023 struct thread *td) 4024{ 4025 4026 return (EBADF); 4027} 4028 4029static int 4030badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4031 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4032 struct thread *td) 4033{ 4034 4035 return (EBADF); 4036} 4037 4038static int 4039badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4040{ 4041 4042 return (0); 4043} 4044 4045struct fileops badfileops = { 4046 .fo_read = badfo_readwrite, 4047 .fo_write = badfo_readwrite, 4048 .fo_truncate = badfo_truncate, 4049 .fo_ioctl = badfo_ioctl, 4050 .fo_poll = badfo_poll, 4051 .fo_kqfilter = badfo_kqfilter, 4052 .fo_stat = badfo_stat, 4053 .fo_close = badfo_close, 4054 .fo_chmod = badfo_chmod, 4055 .fo_chown = badfo_chown, 4056 .fo_sendfile = badfo_sendfile, 4057 .fo_fill_kinfo = badfo_fill_kinfo, 4058}; 4059 4060int 4061invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4062 int flags, struct thread *td) 4063{ 4064 4065 return (EOPNOTSUPP); 4066} 4067 4068int 4069invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4070 struct thread *td) 4071{ 4072 4073 return (EINVAL); 4074} 4075 4076int 4077invfo_ioctl(struct file *fp, u_long com, void *data, 4078 struct ucred *active_cred, struct thread *td) 4079{ 4080 4081 return (ENOTTY); 4082} 4083 4084int 4085invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4086 struct thread *td) 4087{ 4088 4089 return (poll_no_poll(events)); 4090} 4091 4092int 4093invfo_kqfilter(struct file *fp, struct knote *kn) 4094{ 4095 4096 return (EINVAL); 4097} 4098 4099int 4100invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4101 struct thread *td) 4102{ 4103 4104 return (EINVAL); 4105} 4106 4107int 4108invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4109 struct thread *td) 4110{ 4111 4112 return (EINVAL); 4113} 4114 4115int 4116invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4117 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4118 struct thread *td) 4119{ 4120 4121 return (EINVAL); 4122} 4123 4124/*-------------------------------------------------------------------*/ 4125 4126/* 4127 * File Descriptor pseudo-device driver (/dev/fd/). 4128 * 4129 * Opening minor device N dup()s the file (if any) connected to file 4130 * descriptor N belonging to the calling process. Note that this driver 4131 * consists of only the ``open()'' routine, because all subsequent 4132 * references to this file will be direct to the other driver. 4133 * 4134 * XXX: we could give this one a cloning event handler if necessary. 4135 */ 4136 4137/* ARGSUSED */ 4138static int 4139fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4140{ 4141 4142 /* 4143 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4144 * the file descriptor being sought for duplication. The error 4145 * return ensures that the vnode for this device will be released 4146 * by vn_open. Open will detect this special error and take the 4147 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4148 * will simply report the error. 4149 */ 4150 td->td_dupfd = dev2unit(dev); 4151 return (ENODEV); 4152} 4153 4154static struct cdevsw fildesc_cdevsw = { 4155 .d_version = D_VERSION, 4156 .d_open = fdopen, 4157 .d_name = "FD", 4158}; 4159 4160static void 4161fildesc_drvinit(void *unused) 4162{ 4163 struct cdev *dev; 4164 4165 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4166 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4167 make_dev_alias(dev, "stdin"); 4168 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4169 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4170 make_dev_alias(dev, "stdout"); 4171 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4172 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4173 make_dev_alias(dev, "stderr"); 4174} 4175 4176SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4177