2 * Copyright (c) 2005 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Copyright (c) 1982, 1986, 1989, 1991, 1993
36 * The Regents of the University of California. All rights reserved.
37 * (c) UNIX System Laboratories, Inc.
38 * All or some portions of this file are derived from material licensed
39 * to the University of California by American Telephone and Telegraph
40 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
41 * the permission of UNIX System Laboratories, Inc.
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 * 3. Neither the name of the University nor the names of its contributors
52 * may be used to endorse or promote products derived from this software
53 * without specific prior written permission.
55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94
68 * $FreeBSD: src/sys/kern/kern_descrip.c,v 1.81.2.19 2004/02/28 00:43:31 tegge Exp $
71 #include "opt_compat.h"
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/malloc.h>
75 #include <sys/sysproto.h>
77 #include <sys/device.h>
79 #include <sys/filedesc.h>
80 #include <sys/kernel.h>
81 #include <sys/sysctl.h>
82 #include <sys/vnode.h>
84 #include <sys/nlookup.h>
86 #include <sys/filio.h>
87 #include <sys/fcntl.h>
88 #include <sys/unistd.h>
89 #include <sys/resourcevar.h>
90 #include <sys/event.h>
91 #include <sys/kern_syscall.h>
92 #include <sys/kcore.h>
93 #include <sys/kinfo.h>
97 #include <vm/vm_extern.h>
99 #include <sys/thread2.h>
100 #include <sys/file2.h>
101 #include <sys/spinlock2.h>
103 static void fsetfd_locked(struct filedesc *fdp, struct file *fp, int fd);
104 static void fdreserve_locked (struct filedesc *fdp, int fd0, int incr);
105 static struct file *funsetfd_locked (struct filedesc *fdp, int fd);
106 static void ffree(struct file *fp);
108 static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table");
109 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "file desc to leader",
110 "file desc to leader structures");
111 MALLOC_DEFINE(M_FILE, "file", "Open file structure");
112 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
114 static struct krate krate_uidinfo = { .freq = 1 };
116 static d_open_t fdopen;
119 #define CDEV_MAJOR 22
120 static struct dev_ops fildesc_ops = {
126 * Descriptor management.
128 static struct filelist filehead = LIST_HEAD_INITIALIZER(&filehead);
129 static struct spinlock filehead_spin = SPINLOCK_INITIALIZER(&filehead_spin, "filehead_spin");
130 static int nfiles; /* actual number of open files */
134 * Fixup fd_freefile and fd_lastfile after a descriptor has been cleared.
136 * must be called with fdp->fd_spin exclusively held
140 fdfixup_locked(struct filedesc *fdp, int fd)
142 if (fd < fdp->fd_freefile) {
143 fdp->fd_freefile = fd;
145 while (fdp->fd_lastfile >= 0 &&
146 fdp->fd_files[fdp->fd_lastfile].fp == NULL &&
147 fdp->fd_files[fdp->fd_lastfile].reserved == 0
154 * System calls on descriptors.
157 sys_getdtablesize(struct getdtablesize_args *uap)
159 struct proc *p = curproc;
160 struct plimit *limit = p->p_limit;
163 spin_lock(&limit->p_spin);
164 if (limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX)
167 dtsize = (int)limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur;
168 spin_unlock(&limit->p_spin);
170 if (dtsize > maxfilesperproc)
171 dtsize = maxfilesperproc;
172 if (dtsize < minfilesperproc)
173 dtsize = minfilesperproc;
174 if (p->p_ucred->cr_uid && dtsize > maxfilesperuser)
175 dtsize = maxfilesperuser;
176 uap->sysmsg_result = dtsize;
181 * Duplicate a file descriptor to a particular value.
183 * note: keep in mind that a potential race condition exists when closing
184 * descriptors from a shared descriptor table (via rfork).
187 sys_dup2(struct dup2_args *uap)
192 error = kern_dup(DUP_FIXED, uap->from, uap->to, &fd);
193 uap->sysmsg_fds[0] = fd;
199 * Duplicate a file descriptor.
202 sys_dup(struct dup_args *uap)
207 error = kern_dup(DUP_VARIABLE, uap->fd, 0, &fd);
208 uap->sysmsg_fds[0] = fd;
214 * MPALMOSTSAFE - acquires mplock for fp operations
217 kern_fcntl(int fd, int cmd, union fcntl_dat *dat, struct ucred *cred)
219 struct thread *td = curthread;
220 struct proc *p = td->td_proc;
226 int tmp, error, flg = F_POSIX;
231 * Operations on file descriptors that do not require a file pointer.
235 error = fgetfdflags(p->p_fd, fd, &tmp);
237 dat->fc_cloexec = (tmp & UF_EXCLOSE) ? FD_CLOEXEC : 0;
241 if (dat->fc_cloexec & FD_CLOEXEC)
242 error = fsetfdflags(p->p_fd, fd, UF_EXCLOSE);
244 error = fclrfdflags(p->p_fd, fd, UF_EXCLOSE);
248 error = kern_dup(DUP_VARIABLE | DUP_FCNTL, fd, newmin,
251 case F_DUPFD_CLOEXEC:
253 error = kern_dup(DUP_VARIABLE | DUP_CLOEXEC | DUP_FCNTL,
254 fd, newmin, &dat->fc_fd);
258 error = kern_dup(DUP_FIXED, fd, newmin, &dat->fc_fd);
260 case F_DUP2FD_CLOEXEC:
262 error = kern_dup(DUP_FIXED | DUP_CLOEXEC, fd, newmin,
270 * Operations on file pointers
272 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL)
277 dat->fc_flags = OFLAGS(fp->f_flag);
283 nflags = FFLAGS(dat->fc_flags & ~O_ACCMODE) & FCNTLFLAGS;
284 nflags |= oflags & ~FCNTLFLAGS;
287 if (((nflags ^ oflags) & O_APPEND) && (oflags & FAPPENDONLY))
289 if (error == 0 && ((nflags ^ oflags) & FASYNC)) {
290 tmp = nflags & FASYNC;
291 error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp,
296 * If no error, must be atomically set.
301 nflags = (oflags & ~FCNTLFLAGS) | (nflags & FCNTLFLAGS);
302 if (atomic_cmpset_int(&fp->f_flag, oflags, nflags))
309 error = fo_ioctl(fp, FIOGETOWN, (caddr_t)&dat->fc_owner,
314 error = fo_ioctl(fp, FIOSETOWN, (caddr_t)&dat->fc_owner,
320 /* Fall into F_SETLK */
323 if (fp->f_type != DTYPE_VNODE) {
327 vp = (struct vnode *)fp->f_data;
330 * copyin/lockop may block
332 if (dat->fc_flock.l_whence == SEEK_CUR)
333 dat->fc_flock.l_start += fp->f_offset;
335 switch (dat->fc_flock.l_type) {
337 if ((fp->f_flag & FREAD) == 0) {
341 if ((p->p_leader->p_flags & P_ADVLOCK) == 0) {
342 lwkt_gettoken(&p->p_leader->p_token);
343 p->p_leader->p_flags |= P_ADVLOCK;
344 lwkt_reltoken(&p->p_leader->p_token);
346 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
347 &dat->fc_flock, flg);
350 if ((fp->f_flag & FWRITE) == 0) {
354 if ((p->p_leader->p_flags & P_ADVLOCK) == 0) {
355 lwkt_gettoken(&p->p_leader->p_token);
356 p->p_leader->p_flags |= P_ADVLOCK;
357 lwkt_reltoken(&p->p_leader->p_token);
359 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
360 &dat->fc_flock, flg);
363 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
364 &dat->fc_flock, F_POSIX);
372 * It is possible to race a close() on the descriptor while
373 * we were blocked getting the lock. If this occurs the
374 * close might not have caught the lock.
376 if (checkfdclosed(p->p_fd, fd, fp)) {
377 dat->fc_flock.l_whence = SEEK_SET;
378 dat->fc_flock.l_start = 0;
379 dat->fc_flock.l_len = 0;
380 dat->fc_flock.l_type = F_UNLCK;
381 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
382 F_UNLCK, &dat->fc_flock, F_POSIX);
387 if (fp->f_type != DTYPE_VNODE) {
391 vp = (struct vnode *)fp->f_data;
393 * copyin/lockop may block
395 if (dat->fc_flock.l_type != F_RDLCK &&
396 dat->fc_flock.l_type != F_WRLCK &&
397 dat->fc_flock.l_type != F_UNLCK) {
401 if (dat->fc_flock.l_whence == SEEK_CUR)
402 dat->fc_flock.l_start += fp->f_offset;
403 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK,
404 &dat->fc_flock, F_POSIX);
416 * The file control system call.
419 sys_fcntl(struct fcntl_args *uap)
427 case F_DUPFD_CLOEXEC:
428 case F_DUP2FD_CLOEXEC:
429 dat.fc_fd = uap->arg;
432 dat.fc_cloexec = uap->arg;
435 dat.fc_flags = uap->arg;
438 dat.fc_owner = uap->arg;
443 error = copyin((caddr_t)uap->arg, &dat.fc_flock,
444 sizeof(struct flock));
450 error = kern_fcntl(uap->fd, uap->cmd, &dat, curthread->td_ucred);
456 case F_DUPFD_CLOEXEC:
457 case F_DUP2FD_CLOEXEC:
458 uap->sysmsg_result = dat.fc_fd;
461 uap->sysmsg_result = dat.fc_cloexec;
464 uap->sysmsg_result = dat.fc_flags;
467 uap->sysmsg_result = dat.fc_owner;
470 error = copyout(&dat.fc_flock, (caddr_t)uap->arg,
471 sizeof(struct flock));
480 * Common code for dup, dup2, and fcntl(F_DUPFD).
482 * There are four type flags: DUP_FCNTL, DUP_FIXED, DUP_VARIABLE, and
485 * DUP_FCNTL is for handling EINVAL vs. EBADF differences between
486 * fcntl()'s F_DUPFD and F_DUPFD_CLOEXEC and dup2() (per POSIX).
487 * The next two flags are mutually exclusive, and the fourth is optional.
488 * DUP_FIXED tells kern_dup() to destructively dup over an existing file
489 * descriptor if "new" is already open. DUP_VARIABLE tells kern_dup()
490 * to find the lowest unused file descriptor that is greater than or
491 * equal to "new". DUP_CLOEXEC, which works with either of the first
492 * two flags, sets the close-on-exec flag on the "new" file descriptor.
495 kern_dup(int flags, int old, int new, int *res)
497 struct thread *td = curthread;
498 struct proc *p = td->td_proc;
499 struct filedesc *fdp = p->p_fd;
508 * Verify that we have a valid descriptor to dup from and
509 * possibly to dup to. When the new descriptor is out of
510 * bounds, fcntl()'s F_DUPFD and F_DUPFD_CLOEXEC must
511 * return EINVAL, while dup2() returns EBADF in
514 * NOTE: maxfilesperuser is not applicable to dup()
517 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX)
520 dtsize = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
521 if (dtsize > maxfilesperproc)
522 dtsize = maxfilesperproc;
523 if (dtsize < minfilesperproc)
524 dtsize = minfilesperproc;
526 if (new < 0 || new > dtsize)
527 return (flags & DUP_FCNTL ? EINVAL : EBADF);
529 spin_lock(&fdp->fd_spin);
530 if ((unsigned)old >= fdp->fd_nfiles || fdp->fd_files[old].fp == NULL) {
531 spin_unlock(&fdp->fd_spin);
534 if ((flags & DUP_FIXED) && old == new) {
536 if (flags & DUP_CLOEXEC)
537 fdp->fd_files[new].fileflags |= UF_EXCLOSE;
538 spin_unlock(&fdp->fd_spin);
541 fp = fdp->fd_files[old].fp;
542 oldflags = fdp->fd_files[old].fileflags;
546 * Allocate a new descriptor if DUP_VARIABLE, or expand the table
547 * if the requested descriptor is beyond the current table size.
549 * This can block. Retry if the source descriptor no longer matches
550 * or if our expectation in the expansion case races.
552 * If we are not expanding or allocating a new decriptor, then reset
553 * the target descriptor to a reserved state so we have a uniform
554 * setup for the next code block.
556 if ((flags & DUP_VARIABLE) || new >= fdp->fd_nfiles) {
557 spin_unlock(&fdp->fd_spin);
558 error = fdalloc(p, new, &newfd);
559 spin_lock(&fdp->fd_spin);
561 spin_unlock(&fdp->fd_spin);
568 if (old >= fdp->fd_nfiles || fdp->fd_files[old].fp != fp) {
569 fsetfd_locked(fdp, NULL, newfd);
570 spin_unlock(&fdp->fd_spin);
575 * Check for expansion race
577 if ((flags & DUP_VARIABLE) == 0 && new != newfd) {
578 fsetfd_locked(fdp, NULL, newfd);
579 spin_unlock(&fdp->fd_spin);
584 * Check for ripout, newfd reused old (this case probably
588 fsetfd_locked(fdp, NULL, newfd);
589 spin_unlock(&fdp->fd_spin);
596 if (fdp->fd_files[new].reserved) {
597 spin_unlock(&fdp->fd_spin);
599 kprintf("Warning: dup(): target descriptor %d is reserved, waiting for it to be resolved\n", new);
600 tsleep(fdp, 0, "fdres", hz);
605 * If the target descriptor was never allocated we have
606 * to allocate it. If it was we have to clean out the
607 * old descriptor. delfp inherits the ref from the
610 delfp = fdp->fd_files[new].fp;
611 fdp->fd_files[new].fp = NULL;
612 fdp->fd_files[new].reserved = 1;
614 fdreserve_locked(fdp, new, 1);
615 if (new > fdp->fd_lastfile)
616 fdp->fd_lastfile = new;
622 * NOTE: still holding an exclusive spinlock
626 * If a descriptor is being overwritten we may hve to tell
627 * fdfree() to sleep to ensure that all relevant process
628 * leaders can be traversed in closef().
630 if (delfp != NULL && p->p_fdtol != NULL) {
631 fdp->fd_holdleaderscount++;
636 KASSERT(delfp == NULL || (flags & DUP_FIXED),
637 ("dup() picked an open file"));
640 * Duplicate the source descriptor, update lastfile. If the new
641 * descriptor was not allocated and we aren't replacing an existing
642 * descriptor we have to mark the descriptor as being in use.
644 * The fd_files[] array inherits fp's hold reference.
646 fsetfd_locked(fdp, fp, new);
647 if ((flags & DUP_CLOEXEC) != 0)
648 fdp->fd_files[new].fileflags = oldflags | UF_EXCLOSE;
650 fdp->fd_files[new].fileflags = oldflags & ~UF_EXCLOSE;
651 spin_unlock(&fdp->fd_spin);
656 * If we dup'd over a valid file, we now own the reference to it
657 * and must dispose of it using closef() semantics (as if a
658 * close() were performed on it).
661 if (SLIST_FIRST(&delfp->f_klist))
662 knote_fdclose(delfp, fdp, new);
665 spin_lock(&fdp->fd_spin);
666 fdp->fd_holdleaderscount--;
667 if (fdp->fd_holdleaderscount == 0 &&
668 fdp->fd_holdleaderswakeup != 0) {
669 fdp->fd_holdleaderswakeup = 0;
670 spin_unlock(&fdp->fd_spin);
671 wakeup(&fdp->fd_holdleaderscount);
673 spin_unlock(&fdp->fd_spin);
681 * If sigio is on the list associated with a process or process group,
682 * disable signalling from the device, remove sigio from the list and
686 funsetown(struct sigio **sigiop)
692 if ((sigio = *sigiop) != NULL) {
693 lwkt_gettoken(&sigio_token); /* protect sigio */
694 KKASSERT(sigiop == sigio->sio_myref);
697 lwkt_reltoken(&sigio_token);
702 if (sigio->sio_pgid < 0) {
703 pgrp = sigio->sio_pgrp;
704 sigio->sio_pgrp = NULL;
705 lwkt_gettoken(&pgrp->pg_token);
706 SLIST_REMOVE(&pgrp->pg_sigiolst, sigio, sigio, sio_pgsigio);
707 lwkt_reltoken(&pgrp->pg_token);
709 } else /* if ((*sigiop)->sio_pgid > 0) */ {
711 sigio->sio_proc = NULL;
713 lwkt_gettoken(&p->p_token);
714 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio);
715 lwkt_reltoken(&p->p_token);
718 crfree(sigio->sio_ucred);
719 sigio->sio_ucred = NULL;
720 kfree(sigio, M_SIGIO);
724 * Free a list of sigio structures. Caller is responsible for ensuring
725 * that the list is MPSAFE.
728 funsetownlst(struct sigiolst *sigiolst)
732 while ((sigio = SLIST_FIRST(sigiolst)) != NULL)
733 funsetown(sigio->sio_myref);
737 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
739 * After permission checking, add a sigio structure to the sigio list for
740 * the process or process group.
743 fsetown(pid_t pgid, struct sigio **sigiop)
745 struct proc *proc = NULL;
746 struct pgrp *pgrp = NULL;
763 * Policy - Don't allow a process to FSETOWN a process
764 * in another session.
766 * Remove this test to allow maximum flexibility or
767 * restrict FSETOWN to the current process or process
768 * group for maximum safety.
770 if (proc->p_session != curproc->p_session) {
774 } else /* if (pgid < 0) */ {
775 pgrp = pgfind(-pgid);
782 * Policy - Don't allow a process to FSETOWN a process
783 * in another session.
785 * Remove this test to allow maximum flexibility or
786 * restrict FSETOWN to the current process or process
787 * group for maximum safety.
789 if (pgrp->pg_session != curproc->p_session) {
794 sigio = kmalloc(sizeof(struct sigio), M_SIGIO, M_WAITOK | M_ZERO);
796 KKASSERT(pgrp == NULL);
797 lwkt_gettoken(&proc->p_token);
798 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
799 sigio->sio_proc = proc;
800 lwkt_reltoken(&proc->p_token);
802 KKASSERT(proc == NULL);
803 lwkt_gettoken(&pgrp->pg_token);
804 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
805 sigio->sio_pgrp = pgrp;
806 lwkt_reltoken(&pgrp->pg_token);
809 sigio->sio_pgid = pgid;
810 sigio->sio_ucred = crhold(curthread->td_ucred);
811 /* It would be convenient if p_ruid was in ucred. */
812 sigio->sio_ruid = sigio->sio_ucred->cr_ruid;
813 sigio->sio_myref = sigiop;
815 lwkt_gettoken(&sigio_token);
819 lwkt_reltoken(&sigio_token);
830 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
833 fgetown(struct sigio **sigiop)
838 lwkt_gettoken_shared(&sigio_token);
840 own = (sigio != NULL ? sigio->sio_pgid : 0);
841 lwkt_reltoken(&sigio_token);
847 * Close many file descriptors.
850 sys_closefrom(struct closefrom_args *uap)
852 return(kern_closefrom(uap->fd));
856 * Close all file descriptors greater then or equal to fd
859 kern_closefrom(int fd)
861 struct thread *td = curthread;
862 struct proc *p = td->td_proc;
863 struct filedesc *fdp;
872 * NOTE: This function will skip unassociated descriptors and
873 * reserved descriptors that have not yet been assigned.
874 * fd_lastfile can change as a side effect of kern_close().
876 spin_lock(&fdp->fd_spin);
877 while (fd <= fdp->fd_lastfile) {
878 if (fdp->fd_files[fd].fp != NULL) {
879 spin_unlock(&fdp->fd_spin);
880 /* ok if this races another close */
881 if (kern_close(fd) == EINTR)
883 spin_lock(&fdp->fd_spin);
887 spin_unlock(&fdp->fd_spin);
892 * Close a file descriptor.
895 sys_close(struct close_args *uap)
897 return(kern_close(uap->fd));
906 struct thread *td = curthread;
907 struct proc *p = td->td_proc;
908 struct filedesc *fdp;
916 spin_lock(&fdp->fd_spin);
917 if ((fp = funsetfd_locked(fdp, fd)) == NULL) {
918 spin_unlock(&fdp->fd_spin);
922 if (p->p_fdtol != NULL) {
924 * Ask fdfree() to sleep to ensure that all relevant
925 * process leaders can be traversed in closef().
927 fdp->fd_holdleaderscount++;
932 * we now hold the fp reference that used to be owned by the descriptor
935 spin_unlock(&fdp->fd_spin);
936 if (SLIST_FIRST(&fp->f_klist))
937 knote_fdclose(fp, fdp, fd);
938 error = closef(fp, p);
940 spin_lock(&fdp->fd_spin);
941 fdp->fd_holdleaderscount--;
942 if (fdp->fd_holdleaderscount == 0 &&
943 fdp->fd_holdleaderswakeup != 0) {
944 fdp->fd_holdleaderswakeup = 0;
945 spin_unlock(&fdp->fd_spin);
946 wakeup(&fdp->fd_holdleaderscount);
948 spin_unlock(&fdp->fd_spin);
955 * shutdown_args(int fd, int how)
958 kern_shutdown(int fd, int how)
960 struct thread *td = curthread;
961 struct proc *p = td->td_proc;
967 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL)
969 error = fo_shutdown(fp, how);
979 sys_shutdown(struct shutdown_args *uap)
983 error = kern_shutdown(uap->s, uap->how);
992 kern_fstat(int fd, struct stat *ub)
994 struct thread *td = curthread;
995 struct proc *p = td->td_proc;
1001 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL)
1003 error = fo_stat(fp, ub, td->td_ucred);
1010 * Return status information about a file descriptor.
1013 sys_fstat(struct fstat_args *uap)
1018 error = kern_fstat(uap->fd, &st);
1021 error = copyout(&st, uap->sb, sizeof(st));
1026 * Return pathconf information about a file descriptor.
1031 sys_fpathconf(struct fpathconf_args *uap)
1033 struct thread *td = curthread;
1034 struct proc *p = td->td_proc;
1039 if ((fp = holdfp(p->p_fd, uap->fd, -1)) == NULL)
1042 switch (fp->f_type) {
1045 if (uap->name != _PC_PIPE_BUF) {
1048 uap->sysmsg_result = PIPE_BUF;
1054 vp = (struct vnode *)fp->f_data;
1055 error = VOP_PATHCONF(vp, uap->name, &uap->sysmsg_reg);
1065 static int fdexpand;
1066 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0,
1067 "Number of times a file table has been expanded");
1070 * Grow the file table so it can hold through descriptor (want).
1072 * The fdp's spinlock must be held exclusively on entry and may be held
1073 * exclusively on return. The spinlock may be cycled by the routine.
1076 fdgrow_locked(struct filedesc *fdp, int want)
1078 struct fdnode *newfiles;
1079 struct fdnode *oldfiles;
1082 nf = fdp->fd_nfiles;
1084 /* nf has to be of the form 2^n - 1 */
1086 } while (nf <= want);
1088 spin_unlock(&fdp->fd_spin);
1089 newfiles = kmalloc(nf * sizeof(struct fdnode), M_FILEDESC, M_WAITOK);
1090 spin_lock(&fdp->fd_spin);
1093 * We could have raced another extend while we were not holding
1096 if (fdp->fd_nfiles >= nf) {
1097 spin_unlock(&fdp->fd_spin);
1098 kfree(newfiles, M_FILEDESC);
1099 spin_lock(&fdp->fd_spin);
1103 * Copy the existing ofile and ofileflags arrays
1104 * and zero the new portion of each array.
1106 extra = nf - fdp->fd_nfiles;
1107 bcopy(fdp->fd_files, newfiles, fdp->fd_nfiles * sizeof(struct fdnode));
1108 bzero(&newfiles[fdp->fd_nfiles], extra * sizeof(struct fdnode));
1110 oldfiles = fdp->fd_files;
1111 fdp->fd_files = newfiles;
1112 fdp->fd_nfiles = nf;
1114 if (oldfiles != fdp->fd_builtin_files) {
1115 spin_unlock(&fdp->fd_spin);
1116 kfree(oldfiles, M_FILEDESC);
1117 spin_lock(&fdp->fd_spin);
1123 * Number of nodes in right subtree, including the root.
1126 right_subtree_size(int n)
1128 return (n ^ (n | (n + 1)));
1135 right_ancestor(int n)
1137 return (n | (n + 1));
1144 left_ancestor(int n)
1146 return ((n & (n + 1)) - 1);
1150 * Traverse the in-place binary tree buttom-up adjusting the allocation
1151 * count so scans can determine where free descriptors are located.
1153 * caller must be holding an exclusive spinlock on fdp
1157 fdreserve_locked(struct filedesc *fdp, int fd, int incr)
1160 fdp->fd_files[fd].allocated += incr;
1161 KKASSERT(fdp->fd_files[fd].allocated >= 0);
1162 fd = left_ancestor(fd);
1167 * Reserve a file descriptor for the process. If no error occurs, the
1168 * caller MUST at some point call fsetfd() or assign a file pointer
1169 * or dispose of the reservation.
1172 fdalloc(struct proc *p, int want, int *result)
1174 struct filedesc *fdp = p->p_fd;
1175 struct uidinfo *uip;
1176 int fd, rsize, rsum, node, lim;
1179 * Check dtable size limit
1181 spin_lock(&p->p_limit->p_spin);
1182 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX)
1185 lim = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
1186 spin_unlock(&p->p_limit->p_spin);
1188 if (lim > maxfilesperproc)
1189 lim = maxfilesperproc;
1190 if (lim < minfilesperproc)
1191 lim = minfilesperproc;
1196 * Check that the user has not run out of descriptors (non-root only).
1197 * As a safety measure the dtable is allowed to have at least
1198 * minfilesperproc open fds regardless of the maxfilesperuser limit.
1200 if (p->p_ucred->cr_uid && fdp->fd_nfiles >= minfilesperproc) {
1201 uip = p->p_ucred->cr_uidinfo;
1202 if (uip->ui_openfiles > maxfilesperuser) {
1203 krateprintf(&krate_uidinfo,
1204 "Warning: user %d pid %d (%s) ran out of "
1205 "file descriptors (%d/%d)\n",
1206 p->p_ucred->cr_uid, (int)p->p_pid,
1208 uip->ui_openfiles, maxfilesperuser);
1214 * Grow the dtable if necessary
1216 spin_lock(&fdp->fd_spin);
1217 if (want >= fdp->fd_nfiles)
1218 fdgrow_locked(fdp, want);
1221 * Search for a free descriptor starting at the higher
1222 * of want or fd_freefile. If that fails, consider
1223 * expanding the ofile array.
1225 * NOTE! the 'allocated' field is a cumulative recursive allocation
1226 * count. If we happen to see a value of 0 then we can shortcut
1227 * our search. Otherwise we run through through the tree going
1228 * down branches we know have free descriptor(s) until we hit a
1229 * leaf node. The leaf node will be free but will not necessarily
1230 * have an allocated field of 0.
1233 /* move up the tree looking for a subtree with a free node */
1234 for (fd = max(want, fdp->fd_freefile); fd < min(fdp->fd_nfiles, lim);
1235 fd = right_ancestor(fd)) {
1236 if (fdp->fd_files[fd].allocated == 0)
1239 rsize = right_subtree_size(fd);
1240 if (fdp->fd_files[fd].allocated == rsize)
1241 continue; /* right subtree full */
1244 * Free fd is in the right subtree of the tree rooted at fd.
1245 * Call that subtree R. Look for the smallest (leftmost)
1246 * subtree of R with an unallocated fd: continue moving
1247 * down the left branch until encountering a full left
1248 * subtree, then move to the right.
1250 for (rsum = 0, rsize /= 2; rsize > 0; rsize /= 2) {
1252 rsum += fdp->fd_files[node].allocated;
1253 if (fdp->fd_files[fd].allocated == rsum + rsize) {
1254 fd = node; /* move to the right */
1255 if (fdp->fd_files[node].allocated == 0)
1264 * No space in current array. Expand?
1266 if (fdp->fd_nfiles >= lim) {
1267 spin_unlock(&fdp->fd_spin);
1270 fdgrow_locked(fdp, want);
1274 KKASSERT(fd < fdp->fd_nfiles);
1275 if (fd > fdp->fd_lastfile)
1276 fdp->fd_lastfile = fd;
1277 if (want <= fdp->fd_freefile)
1278 fdp->fd_freefile = fd;
1280 KKASSERT(fdp->fd_files[fd].fp == NULL);
1281 KKASSERT(fdp->fd_files[fd].reserved == 0);
1282 fdp->fd_files[fd].fileflags = 0;
1283 fdp->fd_files[fd].reserved = 1;
1284 fdreserve_locked(fdp, fd, 1);
1285 spin_unlock(&fdp->fd_spin);
1290 * Check to see whether n user file descriptors
1291 * are available to the process p.
1294 fdavail(struct proc *p, int n)
1296 struct filedesc *fdp = p->p_fd;
1297 struct fdnode *fdnode;
1300 spin_lock(&p->p_limit->p_spin);
1301 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX)
1304 lim = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
1305 spin_unlock(&p->p_limit->p_spin);
1307 if (lim > maxfilesperproc)
1308 lim = maxfilesperproc;
1309 if (lim < minfilesperproc)
1310 lim = minfilesperproc;
1312 spin_lock(&fdp->fd_spin);
1313 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) {
1314 spin_unlock(&fdp->fd_spin);
1317 last = min(fdp->fd_nfiles, lim);
1318 fdnode = &fdp->fd_files[fdp->fd_freefile];
1319 for (i = last - fdp->fd_freefile; --i >= 0; ++fdnode) {
1320 if (fdnode->fp == NULL && --n <= 0) {
1321 spin_unlock(&fdp->fd_spin);
1325 spin_unlock(&fdp->fd_spin);
1330 * Revoke open descriptors referencing (f_data, f_type)
1332 * Any revoke executed within a prison is only able to
1333 * revoke descriptors for processes within that prison.
1335 * Returns 0 on success or an error code.
1337 struct fdrevoke_info {
1347 static int fdrevoke_check_callback(struct file *fp, void *vinfo);
1348 static int fdrevoke_proc_callback(struct proc *p, void *vinfo);
1351 fdrevoke(void *f_data, short f_type, struct ucred *cred)
1353 struct fdrevoke_info info;
1356 bzero(&info, sizeof(info));
1360 error = falloc(NULL, &info.nfp, NULL);
1365 * Scan the file pointer table once. dups do not dup file pointers,
1366 * only descriptors, so there is no leak. Set FREVOKED on the fps
1369 allfiles_scan_exclusive(fdrevoke_check_callback, &info);
1372 * If any fps were marked track down the related descriptors
1373 * and close them. Any dup()s at this point will notice
1374 * the FREVOKED already set in the fp and do the right thing.
1376 * Any fps with non-zero msgcounts (aka sent over a unix-domain
1377 * socket) bumped the intransit counter and will require a
1378 * scan. Races against fps leaving the socket are closed by
1379 * the socket code checking for FREVOKED.
1382 allproc_scan(fdrevoke_proc_callback, &info);
1384 unp_revoke_gc(info.nfp);
1390 * Locate matching file pointers directly.
1392 * WARNING: allfiles_scan_exclusive() holds a spinlock through these calls!
1395 fdrevoke_check_callback(struct file *fp, void *vinfo)
1397 struct fdrevoke_info *info = vinfo;
1400 * File pointers already flagged for revokation are skipped.
1402 if (fp->f_flag & FREVOKED)
1406 * If revoking from a prison file pointers created outside of
1407 * that prison, or file pointers without creds, cannot be revoked.
1409 if (info->cred->cr_prison &&
1410 (fp->f_cred == NULL ||
1411 info->cred->cr_prison != fp->f_cred->cr_prison)) {
1416 * If the file pointer matches then mark it for revocation. The
1417 * flag is currently only used by unp_revoke_gc().
1419 * info->found is a heuristic and can race in a SMP environment.
1421 if (info->data == fp->f_data && info->type == fp->f_type) {
1422 atomic_set_int(&fp->f_flag, FREVOKED);
1431 * Locate matching file pointers via process descriptor tables.
1434 fdrevoke_proc_callback(struct proc *p, void *vinfo)
1436 struct fdrevoke_info *info = vinfo;
1437 struct filedesc *fdp;
1441 if (p->p_stat == SIDL || p->p_stat == SZOMB)
1443 if (info->cred->cr_prison &&
1444 info->cred->cr_prison != p->p_ucred->cr_prison) {
1449 * If the controlling terminal of the process matches the
1450 * vnode being revoked we clear the controlling terminal.
1452 * The normal spec_close() may not catch this because it
1453 * uses curproc instead of p.
1455 if (p->p_session && info->type == DTYPE_VNODE &&
1456 info->data == p->p_session->s_ttyvp) {
1457 p->p_session->s_ttyvp = NULL;
1462 * Softref the fdp to prevent it from being destroyed
1464 spin_lock(&p->p_spin);
1465 if ((fdp = p->p_fd) == NULL) {
1466 spin_unlock(&p->p_spin);
1469 atomic_add_int(&fdp->fd_softrefs, 1);
1470 spin_unlock(&p->p_spin);
1473 * Locate and close any matching file descriptors.
1475 spin_lock(&fdp->fd_spin);
1476 for (n = 0; n < fdp->fd_nfiles; ++n) {
1477 if ((fp = fdp->fd_files[n].fp) == NULL)
1479 if (fp->f_flag & FREVOKED) {
1481 fdp->fd_files[n].fp = info->nfp;
1482 spin_unlock(&fdp->fd_spin);
1483 knote_fdclose(fp, fdp, n); /* XXX */
1485 spin_lock(&fdp->fd_spin);
1488 spin_unlock(&fdp->fd_spin);
1489 atomic_subtract_int(&fdp->fd_softrefs, 1);
1495 * Create a new open file structure and reserve a file decriptor
1496 * for the process that refers to it.
1498 * Root creds are checked using lp, or assumed if lp is NULL. If
1499 * resultfd is non-NULL then lp must also be non-NULL. No file
1500 * descriptor is reserved (and no process context is needed) if
1503 * A file pointer with a refcount of 1 is returned. Note that the
1504 * file pointer is NOT associated with the descriptor. If falloc
1505 * returns success, fsetfd() MUST be called to either associate the
1506 * file pointer or clear the reservation.
1509 falloc(struct lwp *lp, struct file **resultfp, int *resultfd)
1511 static struct timeval lastfail;
1514 struct ucred *cred = lp ? lp->lwp_thread->td_ucred : proc0.p_ucred;
1520 * Handle filetable full issues and root overfill.
1522 if (nfiles >= maxfiles - maxfilesrootres &&
1523 (cred->cr_ruid != 0 || nfiles >= maxfiles)) {
1524 if (ppsratecheck(&lastfail, &curfail, 1)) {
1525 kprintf("kern.maxfiles limit exceeded by uid %d, "
1526 "please see tuning(7).\n",
1534 * Allocate a new file descriptor.
1536 fp = kmalloc(sizeof(struct file), M_FILE, M_WAITOK | M_ZERO);
1537 spin_init(&fp->f_spin, "falloc");
1538 SLIST_INIT(&fp->f_klist);
1540 fp->f_ops = &badfileops;
1543 spin_lock(&filehead_spin);
1545 LIST_INSERT_HEAD(&filehead, fp, f_list);
1546 spin_unlock(&filehead_spin);
1548 if ((error = fdalloc(lp->lwp_proc, 0, resultfd)) != 0) {
1561 * Check for races against a file descriptor by determining that the
1562 * file pointer is still associated with the specified file descriptor,
1563 * and a close is not currently in progress.
1566 checkfdclosed(struct filedesc *fdp, int fd, struct file *fp)
1570 spin_lock_shared(&fdp->fd_spin);
1571 if ((unsigned)fd >= fdp->fd_nfiles || fp != fdp->fd_files[fd].fp)
1575 spin_unlock_shared(&fdp->fd_spin);
1580 * Associate a file pointer with a previously reserved file descriptor.
1581 * This function always succeeds.
1583 * If fp is NULL, the file descriptor is returned to the pool.
1587 * (exclusive spinlock must be held on call)
1590 fsetfd_locked(struct filedesc *fdp, struct file *fp, int fd)
1592 KKASSERT((unsigned)fd < fdp->fd_nfiles);
1593 KKASSERT(fdp->fd_files[fd].reserved != 0);
1596 fdp->fd_files[fd].fp = fp;
1597 fdp->fd_files[fd].reserved = 0;
1599 fdp->fd_files[fd].reserved = 0;
1600 fdreserve_locked(fdp, fd, -1);
1601 fdfixup_locked(fdp, fd);
1606 fsetfd(struct filedesc *fdp, struct file *fp, int fd)
1608 spin_lock(&fdp->fd_spin);
1609 fsetfd_locked(fdp, fp, fd);
1610 spin_unlock(&fdp->fd_spin);
1614 * (exclusive spinlock must be held on call)
1618 funsetfd_locked(struct filedesc *fdp, int fd)
1622 if ((unsigned)fd >= fdp->fd_nfiles)
1624 if ((fp = fdp->fd_files[fd].fp) == NULL)
1626 fdp->fd_files[fd].fp = NULL;
1627 fdp->fd_files[fd].fileflags = 0;
1629 fdreserve_locked(fdp, fd, -1);
1630 fdfixup_locked(fdp, fd);
1635 * WARNING: May not be called before initial fsetfd().
1638 fgetfdflags(struct filedesc *fdp, int fd, int *flagsp)
1642 spin_lock(&fdp->fd_spin);
1643 if (((u_int)fd) >= fdp->fd_nfiles) {
1645 } else if (fdp->fd_files[fd].fp == NULL) {
1648 *flagsp = fdp->fd_files[fd].fileflags;
1651 spin_unlock(&fdp->fd_spin);
1656 * WARNING: May not be called before initial fsetfd().
1659 fsetfdflags(struct filedesc *fdp, int fd, int add_flags)
1663 spin_lock(&fdp->fd_spin);
1664 if (((u_int)fd) >= fdp->fd_nfiles) {
1666 } else if (fdp->fd_files[fd].fp == NULL) {
1669 fdp->fd_files[fd].fileflags |= add_flags;
1672 spin_unlock(&fdp->fd_spin);
1677 * WARNING: May not be called before initial fsetfd().
1680 fclrfdflags(struct filedesc *fdp, int fd, int rem_flags)
1684 spin_lock(&fdp->fd_spin);
1685 if (((u_int)fd) >= fdp->fd_nfiles) {
1687 } else if (fdp->fd_files[fd].fp == NULL) {
1690 fdp->fd_files[fd].fileflags &= ~rem_flags;
1693 spin_unlock(&fdp->fd_spin);
1698 * Set/Change/Clear the creds for a fp and synchronize the uidinfo.
1701 fsetcred(struct file *fp, struct ucred *ncr)
1704 struct uidinfo *uip;
1707 if (ocr == NULL || ncr == NULL || ocr->cr_uidinfo != ncr->cr_uidinfo) {
1709 uip = ocr->cr_uidinfo;
1710 atomic_add_int(&uip->ui_openfiles, -1);
1713 uip = ncr->cr_uidinfo;
1714 atomic_add_int(&uip->ui_openfiles, 1);
1725 * Free a file descriptor.
1729 ffree(struct file *fp)
1731 KASSERT((fp->f_count == 0), ("ffree: fp_fcount not 0!"));
1733 if (fp->f_nchandle.ncp)
1734 cache_drop(&fp->f_nchandle);
1739 * called from init_main, initialize filedesc0 for proc0.
1742 fdinit_bootstrap(struct proc *p0, struct filedesc *fdp0, int cmask)
1746 fdp0->fd_refcnt = 1;
1747 fdp0->fd_cmask = cmask;
1748 fdp0->fd_files = fdp0->fd_builtin_files;
1749 fdp0->fd_nfiles = NDFILE;
1750 fdp0->fd_lastfile = -1;
1751 spin_init(&fdp0->fd_spin, "fdinitbootstrap");
1755 * Build a new filedesc structure.
1758 fdinit(struct proc *p)
1760 struct filedesc *newfdp;
1761 struct filedesc *fdp = p->p_fd;
1763 newfdp = kmalloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK|M_ZERO);
1764 spin_lock(&fdp->fd_spin);
1766 newfdp->fd_cdir = fdp->fd_cdir;
1767 vref(newfdp->fd_cdir);
1768 cache_copy(&fdp->fd_ncdir, &newfdp->fd_ncdir);
1772 * rdir may not be set in e.g. proc0 or anything vm_fork'd off of
1773 * proc0, but should unconditionally exist in other processes.
1776 newfdp->fd_rdir = fdp->fd_rdir;
1777 vref(newfdp->fd_rdir);
1778 cache_copy(&fdp->fd_nrdir, &newfdp->fd_nrdir);
1781 newfdp->fd_jdir = fdp->fd_jdir;
1782 vref(newfdp->fd_jdir);
1783 cache_copy(&fdp->fd_njdir, &newfdp->fd_njdir);
1785 spin_unlock(&fdp->fd_spin);
1787 /* Create the file descriptor table. */
1788 newfdp->fd_refcnt = 1;
1789 newfdp->fd_cmask = cmask;
1790 newfdp->fd_files = newfdp->fd_builtin_files;
1791 newfdp->fd_nfiles = NDFILE;
1792 newfdp->fd_lastfile = -1;
1793 spin_init(&newfdp->fd_spin, "fdinit");
1799 * Share a filedesc structure.
1802 fdshare(struct proc *p)
1804 struct filedesc *fdp;
1807 spin_lock(&fdp->fd_spin);
1809 spin_unlock(&fdp->fd_spin);
1814 * Copy a filedesc structure.
1817 fdcopy(struct proc *p, struct filedesc **fpp)
1819 struct filedesc *fdp = p->p_fd;
1820 struct filedesc *newfdp;
1821 struct fdnode *fdnode;
1826 * Certain daemons might not have file descriptors.
1832 * Allocate the new filedesc and fd_files[] array. This can race
1833 * with operations by other threads on the fdp so we have to be
1836 newfdp = kmalloc(sizeof(struct filedesc),
1837 M_FILEDESC, M_WAITOK | M_ZERO | M_NULLOK);
1838 if (newfdp == NULL) {
1843 spin_lock(&fdp->fd_spin);
1844 if (fdp->fd_lastfile < NDFILE) {
1845 newfdp->fd_files = newfdp->fd_builtin_files;
1849 * We have to allocate (N^2-1) entries for our in-place
1850 * binary tree. Allow the table to shrink.
1854 while (ni > fdp->fd_lastfile && ni > NDFILE) {
1858 spin_unlock(&fdp->fd_spin);
1859 newfdp->fd_files = kmalloc(i * sizeof(struct fdnode),
1860 M_FILEDESC, M_WAITOK | M_ZERO);
1863 * Check for race, retry
1865 spin_lock(&fdp->fd_spin);
1866 if (i <= fdp->fd_lastfile) {
1867 spin_unlock(&fdp->fd_spin);
1868 kfree(newfdp->fd_files, M_FILEDESC);
1874 * Dup the remaining fields. vref() and cache_hold() can be
1875 * safely called while holding the read spinlock on fdp.
1877 * The read spinlock on fdp is still being held.
1879 * NOTE: vref and cache_hold calls for the case where the vnode
1880 * or cache entry already has at least one ref may be called
1881 * while holding spin locks.
1883 if ((newfdp->fd_cdir = fdp->fd_cdir) != NULL) {
1884 vref(newfdp->fd_cdir);
1885 cache_copy(&fdp->fd_ncdir, &newfdp->fd_ncdir);
1888 * We must check for fd_rdir here, at least for now because
1889 * the init process is created before we have access to the
1890 * rootvode to take a reference to it.
1892 if ((newfdp->fd_rdir = fdp->fd_rdir) != NULL) {
1893 vref(newfdp->fd_rdir);
1894 cache_copy(&fdp->fd_nrdir, &newfdp->fd_nrdir);
1896 if ((newfdp->fd_jdir = fdp->fd_jdir) != NULL) {
1897 vref(newfdp->fd_jdir);
1898 cache_copy(&fdp->fd_njdir, &newfdp->fd_njdir);
1900 newfdp->fd_refcnt = 1;
1901 newfdp->fd_nfiles = i;
1902 newfdp->fd_lastfile = fdp->fd_lastfile;
1903 newfdp->fd_freefile = fdp->fd_freefile;
1904 newfdp->fd_cmask = fdp->fd_cmask;
1905 spin_init(&newfdp->fd_spin, "fdcopy");
1908 * Copy the descriptor table through (i). This also copies the
1909 * allocation state. Then go through and ref the file pointers
1910 * and clean up any KQ descriptors.
1912 * kq descriptors cannot be copied. Since we haven't ref'd the
1913 * copied files yet we can ignore the return value from funsetfd().
1915 * The read spinlock on fdp is still being held.
1917 bcopy(fdp->fd_files, newfdp->fd_files, i * sizeof(struct fdnode));
1918 for (i = 0 ; i < newfdp->fd_nfiles; ++i) {
1919 fdnode = &newfdp->fd_files[i];
1920 if (fdnode->reserved) {
1921 fdreserve_locked(newfdp, i, -1);
1922 fdnode->reserved = 0;
1923 fdfixup_locked(newfdp, i);
1924 } else if (fdnode->fp) {
1925 if (fdnode->fp->f_type == DTYPE_KQUEUE) {
1926 (void)funsetfd_locked(newfdp, i);
1932 spin_unlock(&fdp->fd_spin);
1938 * Release a filedesc structure.
1940 * NOT MPSAFE (MPSAFE for refs > 1, but the final cleanup code is not MPSAFE)
1943 fdfree(struct proc *p, struct filedesc *repl)
1945 struct filedesc *fdp;
1946 struct fdnode *fdnode;
1948 struct filedesc_to_leader *fdtol;
1954 * Certain daemons might not have file descriptors.
1963 * Severe messing around to follow.
1965 spin_lock(&fdp->fd_spin);
1967 /* Check for special need to clear POSIX style locks */
1969 if (fdtol != NULL) {
1970 KASSERT(fdtol->fdl_refcount > 0,
1971 ("filedesc_to_refcount botch: fdl_refcount=%d",
1972 fdtol->fdl_refcount));
1973 if (fdtol->fdl_refcount == 1 &&
1974 (p->p_leader->p_flags & P_ADVLOCK) != 0) {
1975 for (i = 0; i <= fdp->fd_lastfile; ++i) {
1976 fdnode = &fdp->fd_files[i];
1977 if (fdnode->fp == NULL ||
1978 fdnode->fp->f_type != DTYPE_VNODE) {
1983 spin_unlock(&fdp->fd_spin);
1985 lf.l_whence = SEEK_SET;
1988 lf.l_type = F_UNLCK;
1989 vp = (struct vnode *)fp->f_data;
1990 (void) VOP_ADVLOCK(vp,
1991 (caddr_t)p->p_leader,
1996 spin_lock(&fdp->fd_spin);
2000 if (fdtol->fdl_refcount == 1) {
2001 if (fdp->fd_holdleaderscount > 0 &&
2002 (p->p_leader->p_flags & P_ADVLOCK) != 0) {
2004 * close() or do_dup() has cleared a reference
2005 * in a shared file descriptor table.
2007 fdp->fd_holdleaderswakeup = 1;
2008 ssleep(&fdp->fd_holdleaderscount,
2009 &fdp->fd_spin, 0, "fdlhold", 0);
2012 if (fdtol->fdl_holdcount > 0) {
2014 * Ensure that fdtol->fdl_leader
2015 * remains valid in closef().
2017 fdtol->fdl_wakeup = 1;
2018 ssleep(fdtol, &fdp->fd_spin, 0, "fdlhold", 0);
2022 fdtol->fdl_refcount--;
2023 if (fdtol->fdl_refcount == 0 &&
2024 fdtol->fdl_holdcount == 0) {
2025 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
2026 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
2031 if (fdtol != NULL) {
2032 spin_unlock(&fdp->fd_spin);
2033 kfree(fdtol, M_FILEDESC_TO_LEADER);
2034 spin_lock(&fdp->fd_spin);
2037 if (--fdp->fd_refcnt > 0) {
2038 spin_unlock(&fdp->fd_spin);
2039 spin_lock(&p->p_spin);
2041 spin_unlock(&p->p_spin);
2046 * Even though we are the last reference to the structure allproc
2047 * scans may still reference the structure. Maintain proper
2048 * locks until we can replace p->p_fd.
2050 * Also note that kqueue's closef still needs to reference the
2051 * fdp via p->p_fd, so we have to close the descriptors before
2052 * we replace p->p_fd.
2054 for (i = 0; i <= fdp->fd_lastfile; ++i) {
2055 if (fdp->fd_files[i].fp) {
2056 fp = funsetfd_locked(fdp, i);
2058 spin_unlock(&fdp->fd_spin);
2059 if (SLIST_FIRST(&fp->f_klist))
2060 knote_fdclose(fp, fdp, i);
2062 spin_lock(&fdp->fd_spin);
2066 spin_unlock(&fdp->fd_spin);
2069 * Interlock against an allproc scan operations (typically frevoke).
2071 spin_lock(&p->p_spin);
2073 spin_unlock(&p->p_spin);
2076 * Wait for any softrefs to go away. This race rarely occurs so
2077 * we can use a non-critical-path style poll/sleep loop. The
2078 * race only occurs against allproc scans.
2080 * No new softrefs can occur with the fdp disconnected from the
2083 if (fdp->fd_softrefs) {
2084 kprintf("pid %d: Warning, fdp race avoided\n", p->p_pid);
2085 while (fdp->fd_softrefs)
2086 tsleep(&fdp->fd_softrefs, 0, "fdsoft", 1);
2089 if (fdp->fd_files != fdp->fd_builtin_files)
2090 kfree(fdp->fd_files, M_FILEDESC);
2092 cache_drop(&fdp->fd_ncdir);
2093 vrele(fdp->fd_cdir);
2096 cache_drop(&fdp->fd_nrdir);
2097 vrele(fdp->fd_rdir);
2100 cache_drop(&fdp->fd_njdir);
2101 vrele(fdp->fd_jdir);
2103 kfree(fdp, M_FILEDESC);
2107 * Retrieve and reference the file pointer associated with a descriptor.
2110 holdfp(struct filedesc *fdp, int fd, int flag)
2114 spin_lock_shared(&fdp->fd_spin);
2115 if (((u_int)fd) >= fdp->fd_nfiles) {
2119 if ((fp = fdp->fd_files[fd].fp) == NULL)
2121 if ((fp->f_flag & flag) == 0 && flag != -1) {
2127 spin_unlock_shared(&fdp->fd_spin);
2132 * holdsock() - load the struct file pointer associated
2133 * with a socket into *fpp. If an error occurs, non-zero
2134 * will be returned and *fpp will be set to NULL.
2137 holdsock(struct filedesc *fdp, int fd, struct file **fpp)
2142 spin_lock_shared(&fdp->fd_spin);
2143 if ((unsigned)fd >= fdp->fd_nfiles) {
2148 if ((fp = fdp->fd_files[fd].fp) == NULL) {
2152 if (fp->f_type != DTYPE_SOCKET) {
2159 spin_unlock_shared(&fdp->fd_spin);
2165 * Convert a user file descriptor to a held file pointer.
2168 holdvnode(struct filedesc *fdp, int fd, struct file **fpp)
2173 spin_lock_shared(&fdp->fd_spin);
2174 if ((unsigned)fd >= fdp->fd_nfiles) {
2179 if ((fp = fdp->fd_files[fd].fp) == NULL) {
2183 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) {
2191 spin_unlock_shared(&fdp->fd_spin);
2197 * For setugid programs, we don't want to people to use that setugidness
2198 * to generate error messages which write to a file which otherwise would
2199 * otherwise be off-limits to the process.
2201 * This is a gross hack to plug the hole. A better solution would involve
2202 * a special vop or other form of generalized access control mechanism. We
2203 * go ahead and just reject all procfs file systems accesses as dangerous.
2205 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is
2206 * sufficient. We also don't for check setugidness since we know we are.
2209 is_unsafe(struct file *fp)
2211 if (fp->f_type == DTYPE_VNODE &&
2212 ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS)
2218 * Make this setguid thing safe, if at all possible.
2220 * NOT MPSAFE - scans fdp without spinlocks, calls knote_fdclose()
2223 setugidsafety(struct proc *p)
2225 struct filedesc *fdp = p->p_fd;
2228 /* Certain daemons might not have file descriptors. */
2233 * note: fdp->fd_files may be reallocated out from under us while
2234 * we are blocked in a close. Be careful!
2236 for (i = 0; i <= fdp->fd_lastfile; i++) {
2239 if (fdp->fd_files[i].fp && is_unsafe(fdp->fd_files[i].fp)) {
2243 * NULL-out descriptor prior to close to avoid
2244 * a race while close blocks.
2246 if ((fp = funsetfd_locked(fdp, i)) != NULL) {
2247 knote_fdclose(fp, fdp, i);
2255 * Close any files on exec?
2257 * NOT MPSAFE - scans fdp without spinlocks, calls knote_fdclose()
2260 fdcloseexec(struct proc *p)
2262 struct filedesc *fdp = p->p_fd;
2265 /* Certain daemons might not have file descriptors. */
2270 * We cannot cache fd_files since operations may block and rip
2271 * them out from under us.
2273 for (i = 0; i <= fdp->fd_lastfile; i++) {
2274 if (fdp->fd_files[i].fp != NULL &&
2275 (fdp->fd_files[i].fileflags & UF_EXCLOSE)) {
2279 * NULL-out descriptor prior to close to avoid
2280 * a race while close blocks.
2282 if ((fp = funsetfd_locked(fdp, i)) != NULL) {
2283 knote_fdclose(fp, fdp, i);
2291 * It is unsafe for set[ug]id processes to be started with file
2292 * descriptors 0..2 closed, as these descriptors are given implicit
2293 * significance in the Standard C library. fdcheckstd() will create a
2294 * descriptor referencing /dev/null for each of stdin, stdout, and
2295 * stderr that is not already open.
2297 * NOT MPSAFE - calls falloc, vn_open, etc
2300 fdcheckstd(struct lwp *lp)
2302 struct nlookupdata nd;
2303 struct filedesc *fdp;
2306 int i, error, flags, devnull;
2308 fdp = lp->lwp_proc->p_fd;
2313 for (i = 0; i < 3; i++) {
2314 if (fdp->fd_files[i].fp != NULL)
2317 if ((error = falloc(lp, &fp, &devnull)) != 0)
2320 error = nlookup_init(&nd, "/dev/null", UIO_SYSSPACE,
2321 NLC_FOLLOW|NLC_LOCKVP);
2322 flags = FREAD | FWRITE;
2324 error = vn_open(&nd, fp, flags, 0);
2326 fsetfd(fdp, fp, devnull);
2328 fsetfd(fdp, NULL, devnull);
2333 KKASSERT(i == devnull);
2335 error = kern_dup(DUP_FIXED, devnull, i, &retval);
2344 * Internal form of close.
2345 * Decrement reference count on file structure.
2346 * Note: td and/or p may be NULL when closing a file
2347 * that was being passed in a message.
2349 * MPALMOSTSAFE - acquires mplock for VOP operations
2352 closef(struct file *fp, struct proc *p)
2356 struct filedesc_to_leader *fdtol;
2362 * POSIX record locking dictates that any close releases ALL
2363 * locks owned by this process. This is handled by setting
2364 * a flag in the unlock to free ONLY locks obeying POSIX
2365 * semantics, and not to free BSD-style file locks.
2366 * If the descriptor was in a message, POSIX-style locks
2367 * aren't passed with the descriptor.
2369 if (p != NULL && fp->f_type == DTYPE_VNODE &&
2370 (((struct vnode *)fp->f_data)->v_flag & VMAYHAVELOCKS)
2372 if ((p->p_leader->p_flags & P_ADVLOCK) != 0) {
2373 lf.l_whence = SEEK_SET;
2376 lf.l_type = F_UNLCK;
2377 vp = (struct vnode *)fp->f_data;
2378 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
2382 if (fdtol != NULL) {
2383 lwkt_gettoken(&p->p_token);
2385 * Handle special case where file descriptor table
2386 * is shared between multiple process leaders.
2388 for (fdtol = fdtol->fdl_next;
2389 fdtol != p->p_fdtol;
2390 fdtol = fdtol->fdl_next) {
2391 if ((fdtol->fdl_leader->p_flags &
2394 fdtol->fdl_holdcount++;
2395 lf.l_whence = SEEK_SET;
2398 lf.l_type = F_UNLCK;
2399 vp = (struct vnode *)fp->f_data;
2400 (void) VOP_ADVLOCK(vp,
2401 (caddr_t)fdtol->fdl_leader,
2402 F_UNLCK, &lf, F_POSIX);
2403 fdtol->fdl_holdcount--;
2404 if (fdtol->fdl_holdcount == 0 &&
2405 fdtol->fdl_wakeup != 0) {
2406 fdtol->fdl_wakeup = 0;
2410 lwkt_reltoken(&p->p_token);
2417 * fhold() can only be called if f_count is already at least 1 (i.e. the
2418 * caller of fhold() already has a reference to the file pointer in some
2421 * Atomic ops are used for incrementing and decrementing f_count before
2422 * the 1->0 transition. f_count 1->0 transition is special, see the
2423 * comment in fdrop().
2426 fhold(struct file *fp)
2428 /* 0->1 transition will never work */
2429 KASSERT(fp->f_count > 0, ("fhold: invalid f_count %d", fp->f_count));
2430 atomic_add_int(&fp->f_count, 1);
2434 * fdrop() - drop a reference to a descriptor
2437 fdrop(struct file *fp)
2441 int error, do_free = 0;
2445 * Simple atomic_fetchadd_int(f_count, -1) here will cause use-
2446 * after-free or double free (due to f_count 0->1 transition), if
2447 * fhold() is called on the fps found through filehead iteration.
2450 int count = fp->f_count;
2453 KASSERT(count > 0, ("fdrop: invalid f_count %d", count));
2456 * About to drop the last reference, hold the
2457 * filehead spin lock and drop it, so that no
2458 * one could see this fp through filehead anymore,
2459 * let alone fhold() this fp.
2461 spin_lock(&filehead_spin);
2462 if (atomic_cmpset_int(&fp->f_count, count, 0)) {
2463 LIST_REMOVE(fp, f_list);
2465 spin_unlock(&filehead_spin);
2466 do_free = 1; /* free this fp */
2469 spin_unlock(&filehead_spin);
2471 } else if (atomic_cmpset_int(&fp->f_count, count, count - 1)) {
2479 KKASSERT(SLIST_FIRST(&fp->f_klist) == NULL);
2482 * The last reference has gone away, we own the fp structure free
2485 if (fp->f_count < 0)
2486 panic("fdrop: count < 0");
2487 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE &&
2488 (((struct vnode *)fp->f_data)->v_flag & VMAYHAVELOCKS)
2490 lf.l_whence = SEEK_SET;
2493 lf.l_type = F_UNLCK;
2494 vp = (struct vnode *)fp->f_data;
2495 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, 0);
2497 if (fp->f_ops != &badfileops)
2498 error = fo_close(fp);
2506 * Apply an advisory lock on a file descriptor.
2508 * Just attempt to get a record lock of the requested type on
2509 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0).
2514 sys_flock(struct flock_args *uap)
2516 struct proc *p = curproc;
2522 if ((fp = holdfp(p->p_fd, uap->fd, -1)) == NULL)
2524 if (fp->f_type != DTYPE_VNODE) {
2528 vp = (struct vnode *)fp->f_data;
2529 lf.l_whence = SEEK_SET;
2532 if (uap->how & LOCK_UN) {
2533 lf.l_type = F_UNLCK;
2534 atomic_clear_int(&fp->f_flag, FHASLOCK); /* race ok */
2535 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, 0);
2538 if (uap->how & LOCK_EX)
2539 lf.l_type = F_WRLCK;
2540 else if (uap->how & LOCK_SH)
2541 lf.l_type = F_RDLCK;
2546 if (uap->how & LOCK_NB)
2547 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 0);
2549 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_WAIT);
2550 atomic_set_int(&fp->f_flag, FHASLOCK); /* race ok */
2557 * File Descriptor pseudo-device driver (/dev/fd/).
2559 * Opening minor device N dup()s the file (if any) connected to file
2560 * descriptor N belonging to the calling process. Note that this driver
2561 * consists of only the ``open()'' routine, because all subsequent
2562 * references to this file will be direct to the other driver.
2565 fdopen(struct dev_open_args *ap)
2567 thread_t td = curthread;
2569 KKASSERT(td->td_lwp != NULL);
2572 * XXX Kludge: set curlwp->lwp_dupfd to contain the value of the
2573 * the file descriptor being sought for duplication. The error
2574 * return ensures that the vnode for this device will be released
2575 * by vn_open. Open will detect this special error and take the
2576 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
2577 * will simply report the error.
2579 td->td_lwp->lwp_dupfd = minor(ap->a_head.a_dev);
2584 * The caller has reserved the file descriptor dfd for us. On success we
2585 * must fsetfd() it. On failure the caller will clean it up.
2588 dupfdopen(struct filedesc *fdp, int dfd, int sfd, int mode, int error)
2594 if ((wfp = holdfp(fdp, sfd, -1)) == NULL)
2598 * Close a revoke/dup race. Duping a descriptor marked as revoked
2599 * will dup a dummy descriptor instead of the real one.
2601 if (wfp->f_flag & FREVOKED) {
2602 kprintf("Warning: attempt to dup() a revoked descriptor\n");
2605 werror = falloc(NULL, &wfp, NULL);
2611 * There are two cases of interest here.
2613 * For ENODEV simply dup sfd to file descriptor dfd and return.
2615 * For ENXIO steal away the file structure from sfd and store it
2616 * dfd. sfd is effectively closed by this operation.
2618 * Any other error code is just returned.
2623 * Check that the mode the file is being opened for is a
2624 * subset of the mode of the existing descriptor.
2626 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
2630 spin_lock(&fdp->fd_spin);
2631 fdp->fd_files[dfd].fileflags = fdp->fd_files[sfd].fileflags;
2632 fsetfd_locked(fdp, wfp, dfd);
2633 spin_unlock(&fdp->fd_spin);
2638 * Steal away the file pointer from dfd, and stuff it into indx.
2640 spin_lock(&fdp->fd_spin);
2641 fdp->fd_files[dfd].fileflags = fdp->fd_files[sfd].fileflags;
2642 fsetfd(fdp, wfp, dfd);
2643 if ((xfp = funsetfd_locked(fdp, sfd)) != NULL) {
2644 spin_unlock(&fdp->fd_spin);
2647 spin_unlock(&fdp->fd_spin);
2659 * NOT MPSAFE - I think these refer to a common file descriptor table
2660 * and we need to spinlock that to link fdtol in.
2662 struct filedesc_to_leader *
2663 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
2664 struct proc *leader)
2666 struct filedesc_to_leader *fdtol;
2668 fdtol = kmalloc(sizeof(struct filedesc_to_leader),
2669 M_FILEDESC_TO_LEADER, M_WAITOK | M_ZERO);
2670 fdtol->fdl_refcount = 1;
2671 fdtol->fdl_holdcount = 0;
2672 fdtol->fdl_wakeup = 0;
2673 fdtol->fdl_leader = leader;
2675 fdtol->fdl_next = old->fdl_next;
2676 fdtol->fdl_prev = old;
2677 old->fdl_next = fdtol;
2678 fdtol->fdl_next->fdl_prev = fdtol;
2680 fdtol->fdl_next = fdtol;
2681 fdtol->fdl_prev = fdtol;
2687 * Scan all file pointers in the system. The callback is made with
2688 * the master list spinlock held exclusively.
2691 allfiles_scan_exclusive(int (*callback)(struct file *, void *), void *data)
2696 spin_lock(&filehead_spin);
2697 LIST_FOREACH(fp, &filehead, f_list) {
2698 res = callback(fp, data);
2702 spin_unlock(&filehead_spin);
2706 * Get file structures.
2708 * NOT MPSAFE - process list scan, SYSCTL_OUT (probably not mpsafe)
2711 struct sysctl_kern_file_info {
2714 struct sysctl_req *req;
2717 static int sysctl_kern_file_callback(struct proc *p, void *data);
2720 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
2722 struct sysctl_kern_file_info info;
2725 * Note: because the number of file descriptors is calculated
2726 * in different ways for sizing vs returning the data,
2727 * there is information leakage from the first loop. However,
2728 * it is of a similar order of magnitude to the leakage from
2729 * global system statistics such as kern.openfiles.
2731 * When just doing a count, note that we cannot just count
2732 * the elements and add f_count via the filehead list because
2733 * threaded processes share their descriptor table and f_count might
2734 * still be '1' in that case.
2736 * Since the SYSCTL op can block, we must hold the process to
2737 * prevent it being ripped out from under us either in the
2738 * file descriptor loop or in the greater LIST_FOREACH. The
2739 * process may be in varying states of disrepair. If the process
2740 * is in SZOMB we may have caught it just as it is being removed
2741 * from the allproc list, we must skip it in that case to maintain
2742 * an unbroken chain through the allproc list.
2747 allproc_scan(sysctl_kern_file_callback, &info);
2750 * When just calculating the size, overestimate a bit to try to
2751 * prevent system activity from causing the buffer-fill call
2754 if (req->oldptr == NULL) {
2755 info.count = (info.count + 16) + (info.count / 10);
2756 info.error = SYSCTL_OUT(req, NULL,
2757 info.count * sizeof(struct kinfo_file));
2759 return (info.error);
2763 sysctl_kern_file_callback(struct proc *p, void *data)
2765 struct sysctl_kern_file_info *info = data;
2766 struct kinfo_file kf;
2767 struct filedesc *fdp;
2772 if (p->p_stat == SIDL || p->p_stat == SZOMB)
2774 if (!(PRISON_CHECK(info->req->td->td_ucred, p->p_ucred) != 0))
2778 * Softref the fdp to prevent it from being destroyed
2780 spin_lock(&p->p_spin);
2781 if ((fdp = p->p_fd) == NULL) {
2782 spin_unlock(&p->p_spin);
2785 atomic_add_int(&fdp->fd_softrefs, 1);
2786 spin_unlock(&p->p_spin);
2789 * The fdp's own spinlock prevents the contents from being
2792 spin_lock_shared(&fdp->fd_spin);
2793 for (n = 0; n < fdp->fd_nfiles; ++n) {
2794 if ((fp = fdp->fd_files[n].fp) == NULL)
2796 if (info->req->oldptr == NULL) {
2799 uid = p->p_ucred ? p->p_ucred->cr_uid : -1;
2800 kcore_make_file(&kf, fp, p->p_pid, uid, n);
2801 spin_unlock_shared(&fdp->fd_spin);
2802 info->error = SYSCTL_OUT(info->req, &kf, sizeof(kf));
2803 spin_lock_shared(&fdp->fd_spin);
2808 spin_unlock_shared(&fdp->fd_spin);
2809 atomic_subtract_int(&fdp->fd_softrefs, 1);
2815 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD,
2816 0, 0, sysctl_kern_file, "S,file", "Entire file table");
2818 SYSCTL_INT(_kern, OID_AUTO, minfilesperproc, CTLFLAG_RW,
2819 &minfilesperproc, 0, "Minimum files allowed open per process");
2820 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
2821 &maxfilesperproc, 0, "Maximum files allowed open per process");
2822 SYSCTL_INT(_kern, OID_AUTO, maxfilesperuser, CTLFLAG_RW,
2823 &maxfilesperuser, 0, "Maximum files allowed open per user");
2825 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
2826 &maxfiles, 0, "Maximum number of files");
2828 SYSCTL_INT(_kern, OID_AUTO, maxfilesrootres, CTLFLAG_RW,
2829 &maxfilesrootres, 0, "Descriptors reserved for root use");
2831 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
2832 &nfiles, 0, "System-wide number of open files");
2835 fildesc_drvinit(void *unused)
2839 for (fd = 0; fd < NUMFDESC; fd++) {
2840 make_dev(&fildesc_ops, fd,
2841 UID_BIN, GID_BIN, 0666, "fd/%d", fd);
2844 make_dev(&fildesc_ops, 0, UID_ROOT, GID_WHEEL, 0666, "stdin");
2845 make_dev(&fildesc_ops, 1, UID_ROOT, GID_WHEEL, 0666, "stdout");
2846 make_dev(&fildesc_ops, 2, UID_ROOT, GID_WHEEL, 0666, "stderr");
2849 struct fileops badfileops = {
2850 .fo_read = badfo_readwrite,
2851 .fo_write = badfo_readwrite,
2852 .fo_ioctl = badfo_ioctl,
2853 .fo_kqfilter = badfo_kqfilter,
2854 .fo_stat = badfo_stat,
2855 .fo_close = badfo_close,
2856 .fo_shutdown = badfo_shutdown
2870 badfo_ioctl(struct file *fp, u_long com, caddr_t data,
2871 struct ucred *cred, struct sysmsg *msgv)
2877 * Must return an error to prevent registration, typically
2878 * due to a revoked descriptor (file_filtops assigned).
2881 badfo_kqfilter(struct file *fp, struct knote *kn)
2883 return (EOPNOTSUPP);
2887 badfo_stat(struct file *fp, struct stat *sb, struct ucred *cred)
2893 badfo_close(struct file *fp)
2899 badfo_shutdown(struct file *fp, int how)
2905 nofo_shutdown(struct file *fp, int how)
2907 return (EOPNOTSUPP);
2910 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE + CDEV_MAJOR,
2911 fildesc_drvinit,NULL);