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.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
34 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include "opt_capsicum.h"
41 #include "opt_compat.h"
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
48 #include <sys/capsicum.h>
50 #include <sys/fcntl.h>
52 #include <sys/filedesc.h>
53 #include <sys/filio.h>
55 #include <sys/kernel.h>
56 #include <sys/limits.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>
65 #include <sys/protosw.h>
66 #include <sys/racct.h>
67 #include <sys/resourcevar.h>
69 #include <sys/signalvar.h>
70 #include <sys/socketvar.h>
73 #include <sys/syscallsubr.h>
74 #include <sys/sysctl.h>
75 #include <sys/sysproto.h>
76 #include <sys/unistd.h>
78 #include <sys/vnode.h>
80 #include <sys/ktrace.h>
85 #include <security/audit/audit.h>
92 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
93 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
94 "file desc to leader structures");
95 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
96 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities");
98 MALLOC_DECLARE(M_FADVISE);
100 static uma_zone_t file_zone;
102 static int closefp(struct filedesc *fdp, int fd, struct file *fp,
103 struct thread *td, int holdleaders);
104 static int do_dup(struct thread *td, int flags, int old, int new,
106 static int fd_first_free(struct filedesc *fdp, int low, int size);
107 static int fd_last_used(struct filedesc *fdp, int size);
108 static void fdgrowtable(struct filedesc *fdp, int nfd);
109 static void fdgrowtable_exp(struct filedesc *fdp, int nfd);
110 static void fdunused(struct filedesc *fdp, int fd);
111 static void fdused(struct filedesc *fdp, int fd);
112 static int getmaxfd(struct proc *p);
114 /* Flags for do_dup() */
115 #define DUP_FIXED 0x1 /* Force fixed allocation. */
116 #define DUP_FCNTL 0x2 /* fcntl()-style errors. */
117 #define DUP_CLOEXEC 0x4 /* Atomically set FD_CLOEXEC. */
122 * - An array of open file descriptors (fd_ofiles)
123 * - An array of file flags (fd_ofileflags)
124 * - A bitmap recording which descriptors are in use (fd_map)
126 * A process starts out with NDFILE descriptors. The value of NDFILE has
127 * been selected based the historical limit of 20 open files, and an
128 * assumption that the majority of processes, especially short-lived
129 * processes like shells, will never need more.
131 * If this initial allocation is exhausted, a larger descriptor table and
132 * map are allocated dynamically, and the pointers in the process's struct
133 * filedesc are updated to point to those. This is repeated every time
134 * the process runs out of file descriptors (provided it hasn't hit its
137 * Since threads may hold references to individual descriptor table
138 * entries, the tables are never freed. Instead, they are placed on a
139 * linked list and freed only when the struct filedesc is released.
142 #define NDSLOTSIZE sizeof(NDSLOTTYPE)
143 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT)
144 #define NDSLOT(x) ((x) / NDENTRIES)
145 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
146 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES)
149 * SLIST entry used to keep track of ofiles which must be reclaimed when
153 struct filedescent *ft_table;
154 SLIST_ENTRY(freetable) ft_next;
158 * Initial allocation: a filedesc structure + the head of SLIST used to
159 * keep track of old ofiles + enough space for NDFILE descriptors.
162 struct filedesc fd_fd;
163 SLIST_HEAD(, freetable) fd_free;
164 struct filedescent fd_dfiles[NDFILE];
165 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
169 * Descriptor management.
171 volatile int openfiles; /* actual number of open files */
172 struct mtx sigio_lock; /* mtx to protect pointers to sigio */
173 void (*mq_fdclose)(struct thread *td, int fd, struct file *fp);
175 /* A mutex to protect the association between a proc and filedesc. */
176 static struct mtx fdesc_mtx;
179 * If low >= size, just return low. Otherwise find the first zero bit in the
180 * given bitmap, starting at low and not exceeding size - 1. Return size if
184 fd_first_free(struct filedesc *fdp, int low, int size)
186 NDSLOTTYPE *map = fdp->fd_map;
194 if (low % NDENTRIES) {
195 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
196 if ((mask &= ~map[off]) != 0UL)
197 return (off * NDENTRIES + ffsl(mask) - 1);
200 for (maxoff = NDSLOTS(size); off < maxoff; ++off)
201 if (map[off] != ~0UL)
202 return (off * NDENTRIES + ffsl(~map[off]) - 1);
207 * Find the highest non-zero bit in the given bitmap, starting at 0 and
208 * not exceeding size - 1. Return -1 if not found.
211 fd_last_used(struct filedesc *fdp, int size)
213 NDSLOTTYPE *map = fdp->fd_map;
218 if (size % NDENTRIES) {
219 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES));
220 if ((mask &= map[off]) != 0)
221 return (off * NDENTRIES + flsl(mask) - 1);
224 for (minoff = NDSLOT(0); off >= minoff; --off)
226 return (off * NDENTRIES + flsl(map[off]) - 1);
231 fdisused(struct filedesc *fdp, int fd)
234 FILEDESC_LOCK_ASSERT(fdp);
236 KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
237 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
239 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
243 * Mark a file descriptor as used.
246 fdused(struct filedesc *fdp, int fd)
249 FILEDESC_XLOCK_ASSERT(fdp);
251 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd));
253 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
254 if (fd > fdp->fd_lastfile)
255 fdp->fd_lastfile = fd;
256 if (fd == fdp->fd_freefile)
257 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles);
261 * Mark a file descriptor as unused.
264 fdunused(struct filedesc *fdp, int fd)
267 FILEDESC_XLOCK_ASSERT(fdp);
269 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd));
270 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
271 ("fd=%d is still in use", fd));
273 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
274 if (fd < fdp->fd_freefile)
275 fdp->fd_freefile = fd;
276 if (fd == fdp->fd_lastfile)
277 fdp->fd_lastfile = fd_last_used(fdp, fd);
281 * Free a file descriptor.
283 * Avoid some work if fdp is about to be destroyed.
286 _fdfree(struct filedesc *fdp, int fd, int last)
288 struct filedescent *fde;
290 fde = &fdp->fd_ofiles[fd];
293 seq_write_begin(&fde->fde_seq);
295 filecaps_free(&fde->fde_caps);
298 bzero(fde, fde_change_size);
301 seq_write_end(&fde->fde_seq);
306 fdfree(struct filedesc *fdp, int fd)
313 fdfree_last(struct filedesc *fdp, int fd)
320 * System calls on descriptors.
322 #ifndef _SYS_SYSPROTO_H_
323 struct getdtablesize_args {
329 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap)
331 struct proc *p = td->td_proc;
336 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
337 lim = racct_get_limit(td->td_proc, RACCT_NOFILE);
339 if (lim < td->td_retval[0])
340 td->td_retval[0] = lim;
345 * Duplicate a file descriptor to a particular value.
347 * Note: keep in mind that a potential race condition exists when closing
348 * descriptors from a shared descriptor table (via rfork).
350 #ifndef _SYS_SYSPROTO_H_
358 sys_dup2(struct thread *td, struct dup2_args *uap)
361 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to,
366 * Duplicate a file descriptor.
368 #ifndef _SYS_SYSPROTO_H_
375 sys_dup(struct thread *td, struct dup_args *uap)
378 return (do_dup(td, 0, (int)uap->fd, 0, td->td_retval));
382 * The file control system call.
384 #ifndef _SYS_SYSPROTO_H_
393 sys_fcntl(struct thread *td, struct fcntl_args *uap)
396 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg));
400 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg)
413 * Convert old flock structure to new.
415 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl));
416 fl.l_start = ofl.l_start;
417 fl.l_len = ofl.l_len;
418 fl.l_pid = ofl.l_pid;
419 fl.l_type = ofl.l_type;
420 fl.l_whence = ofl.l_whence;
434 arg1 = (intptr_t)&fl;
440 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl));
441 arg1 = (intptr_t)&fl;
449 error = kern_fcntl(td, fd, cmd, arg1);
452 if (cmd == F_OGETLK) {
453 ofl.l_start = fl.l_start;
454 ofl.l_len = fl.l_len;
455 ofl.l_pid = fl.l_pid;
456 ofl.l_type = fl.l_type;
457 ofl.l_whence = fl.l_whence;
458 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl));
459 } else if (cmd == F_GETLK) {
460 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl));
466 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
468 struct filedesc *fdp;
470 struct file *fp, *fp2;
471 struct filedescent *fde;
487 error = do_dup(td, DUP_FCNTL, fd, tmp, td->td_retval);
490 case F_DUPFD_CLOEXEC:
492 error = do_dup(td, DUP_FCNTL | DUP_CLOEXEC, fd, tmp,
498 error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval);
501 case F_DUP2FD_CLOEXEC:
503 error = do_dup(td, DUP_FIXED | DUP_CLOEXEC, fd, tmp,
509 if (fget_locked(fdp, fd) == NULL) {
510 FILEDESC_SUNLOCK(fdp);
514 fde = &fdp->fd_ofiles[fd];
516 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0;
517 FILEDESC_SUNLOCK(fdp);
522 if (fget_locked(fdp, fd) == NULL) {
523 FILEDESC_XUNLOCK(fdp);
527 fde = &fdp->fd_ofiles[fd];
528 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) |
529 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
530 FILEDESC_XUNLOCK(fdp);
534 error = fget_unlocked(fdp, fd,
535 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp, NULL);
538 td->td_retval[0] = OFLAGS(fp->f_flag);
543 error = fget_unlocked(fdp, fd,
544 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp, NULL);
548 tmp = flg = fp->f_flag;
550 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
551 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
552 tmp = fp->f_flag & FNONBLOCK;
553 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
558 tmp = fp->f_flag & FASYNC;
559 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
564 atomic_clear_int(&fp->f_flag, FNONBLOCK);
566 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
571 error = fget_unlocked(fdp, fd,
572 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp, NULL);
575 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
577 td->td_retval[0] = tmp;
582 error = fget_unlocked(fdp, fd,
583 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp, NULL);
587 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
592 error = priv_check(td, PRIV_NFS_LOCKD);
600 /* FALLTHROUGH F_SETLK */
604 cap_rights_init(&rights, CAP_FLOCK);
605 error = fget_unlocked(fdp, fd, &rights, 0, &fp, NULL);
608 if (fp->f_type != DTYPE_VNODE) {
614 flp = (struct flock *)arg;
615 if (flp->l_whence == SEEK_CUR) {
616 foffset = foffset_get(fp);
619 foffset > OFF_MAX - flp->l_start)) {
620 FILEDESC_SUNLOCK(fdp);
625 flp->l_start += foffset;
629 switch (flp->l_type) {
631 if ((fp->f_flag & FREAD) == 0) {
635 PROC_LOCK(p->p_leader);
636 p->p_leader->p_flag |= P_ADVLOCK;
637 PROC_UNLOCK(p->p_leader);
638 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
642 if ((fp->f_flag & FWRITE) == 0) {
646 PROC_LOCK(p->p_leader);
647 p->p_leader->p_flag |= P_ADVLOCK;
648 PROC_UNLOCK(p->p_leader);
649 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
653 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
658 * Temporary api for testing remote lock
661 if (flg != F_REMOTE) {
665 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
666 F_UNLCKSYS, flp, flg);
672 if (error != 0 || flp->l_type == F_UNLCK ||
673 flp->l_type == F_UNLCKSYS) {
679 * Check for a race with close.
681 * The vnode is now advisory locked (or unlocked, but this case
682 * is not really important) as the caller requested.
683 * We had to drop the filedesc lock, so we need to recheck if
684 * the descriptor is still valid, because if it was closed
685 * in the meantime we need to remove advisory lock from the
686 * vnode - close on any descriptor leading to an advisory
687 * locked vnode, removes that lock.
688 * We will return 0 on purpose in that case, as the result of
689 * successful advisory lock might have been externally visible
690 * already. This is fine - effectively we pretend to the caller
691 * that the closing thread was a bit slower and that the
692 * advisory lock succeeded before the close.
694 error = fget_unlocked(fdp, fd, &rights, 0, &fp2, NULL);
700 flp->l_whence = SEEK_SET;
703 flp->l_type = F_UNLCK;
704 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
705 F_UNLCK, flp, F_POSIX);
712 error = fget_unlocked(fdp, fd,
713 cap_rights_init(&rights, CAP_FLOCK), 0, &fp, NULL);
716 if (fp->f_type != DTYPE_VNODE) {
721 flp = (struct flock *)arg;
722 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
723 flp->l_type != F_UNLCK) {
728 if (flp->l_whence == SEEK_CUR) {
729 foffset = foffset_get(fp);
730 if ((flp->l_start > 0 &&
731 foffset > OFF_MAX - flp->l_start) ||
733 foffset < OFF_MIN - flp->l_start)) {
734 FILEDESC_SUNLOCK(fdp);
739 flp->l_start += foffset;
742 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
748 arg = arg ? 128 * 1024: 0;
751 error = fget_unlocked(fdp, fd, NULL, 0, &fp, NULL);
754 if (fp->f_type != DTYPE_VNODE) {
761 * Exclusive lock synchronizes against f_seqcount reads and
762 * writes in sequential_heuristic().
764 error = vn_lock(vp, LK_EXCLUSIVE);
770 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
771 fp->f_seqcount = (arg + bsize - 1) / bsize;
772 atomic_set_int(&fp->f_flag, FRDAHEAD);
774 atomic_clear_int(&fp->f_flag, FRDAHEAD);
788 getmaxfd(struct proc *p)
793 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
800 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
803 do_dup(struct thread *td, int flags, int old, int new,
806 struct filedesc *fdp;
807 struct filedescent *oldfde, *newfde;
817 * Verify we have a valid descriptor to dup from and possibly to
818 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
819 * return EINVAL when the new descriptor is out of bounds.
824 return (flags & DUP_FCNTL ? EINVAL : EBADF);
827 return (flags & DUP_FCNTL ? EINVAL : EBADF);
830 if (fget_locked(fdp, old) == NULL) {
831 FILEDESC_XUNLOCK(fdp);
834 oldfde = &fdp->fd_ofiles[old];
835 if (flags & DUP_FIXED && old == new) {
837 if (flags & DUP_CLOEXEC)
838 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE;
839 FILEDESC_XUNLOCK(fdp);
842 fp = oldfde->fde_file;
846 * If the caller specified a file descriptor, make sure the file
847 * table is large enough to hold it, and grab it. Otherwise, just
848 * allocate a new descriptor the usual way.
850 if (flags & DUP_FIXED) {
851 if (new >= fdp->fd_nfiles) {
853 * The resource limits are here instead of e.g.
854 * fdalloc(), because the file descriptor table may be
855 * shared between processes, so we can't really use
856 * racct_add()/racct_sub(). Instead of counting the
857 * number of actually allocated descriptors, just put
858 * the limit on the size of the file descriptor table.
862 error = racct_set(p, RACCT_NOFILE, new + 1);
865 FILEDESC_XUNLOCK(fdp);
870 fdgrowtable_exp(fdp, new + 1);
871 oldfde = &fdp->fd_ofiles[old];
873 newfde = &fdp->fd_ofiles[new];
874 if (newfde->fde_file == NULL)
877 if ((error = fdalloc(td, new, &new)) != 0) {
878 FILEDESC_XUNLOCK(fdp);
882 newfde = &fdp->fd_ofiles[new];
885 KASSERT(fp == oldfde->fde_file, ("old fd has been modified"));
886 KASSERT(old != new, ("new fd is same as old"));
888 delfp = newfde->fde_file;
891 * Duplicate the source descriptor.
894 seq_write_begin(&newfde->fde_seq);
896 filecaps_free(&newfde->fde_caps);
897 memcpy(newfde, oldfde, fde_change_size);
898 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps);
899 if ((flags & DUP_CLOEXEC) != 0)
900 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE;
902 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE;
904 seq_write_end(&newfde->fde_seq);
909 (void) closefp(fdp, new, delfp, td, 1);
910 /* closefp() drops the FILEDESC lock for us. */
912 FILEDESC_XUNLOCK(fdp);
919 * If sigio is on the list associated with a process or process group,
920 * disable signalling from the device, remove sigio from the list and
924 funsetown(struct sigio **sigiop)
934 *(sigio->sio_myref) = NULL;
935 if ((sigio)->sio_pgid < 0) {
936 struct pgrp *pg = (sigio)->sio_pgrp;
938 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
942 struct proc *p = (sigio)->sio_proc;
944 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
949 crfree(sigio->sio_ucred);
950 free(sigio, M_SIGIO);
954 * Free a list of sigio structures.
955 * We only need to lock the SIGIO_LOCK because we have made ourselves
956 * inaccessible to callers of fsetown and therefore do not need to lock
957 * the proc or pgrp struct for the list manipulation.
960 funsetownlst(struct sigiolst *sigiolst)
966 sigio = SLIST_FIRST(sigiolst);
973 * Every entry of the list should belong
974 * to a single proc or pgrp.
976 if (sigio->sio_pgid < 0) {
977 pg = sigio->sio_pgrp;
978 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED);
979 } else /* if (sigio->sio_pgid > 0) */ {
981 PROC_LOCK_ASSERT(p, MA_NOTOWNED);
985 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) {
986 *(sigio->sio_myref) = NULL;
988 KASSERT(sigio->sio_pgid < 0,
989 ("Proc sigio in pgrp sigio list"));
990 KASSERT(sigio->sio_pgrp == pg,
991 ("Bogus pgrp in sigio list"));
993 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio,
996 } else /* if (p != NULL) */ {
997 KASSERT(sigio->sio_pgid > 0,
998 ("Pgrp sigio in proc sigio list"));
999 KASSERT(sigio->sio_proc == p,
1000 ("Bogus proc in sigio list"));
1002 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio,
1007 crfree(sigio->sio_ucred);
1008 free(sigio, M_SIGIO);
1015 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
1017 * After permission checking, add a sigio structure to the sigio list for
1018 * the process or process group.
1021 fsetown(pid_t pgid, struct sigio **sigiop)
1025 struct sigio *sigio;
1035 /* Allocate and fill in the new sigio out of locks. */
1036 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
1037 sigio->sio_pgid = pgid;
1038 sigio->sio_ucred = crhold(curthread->td_ucred);
1039 sigio->sio_myref = sigiop;
1041 sx_slock(&proctree_lock);
1050 * Policy - Don't allow a process to FSETOWN a process
1051 * in another session.
1053 * Remove this test to allow maximum flexibility or
1054 * restrict FSETOWN to the current process or process
1055 * group for maximum safety.
1058 if (proc->p_session != curthread->td_proc->p_session) {
1064 } else /* if (pgid < 0) */ {
1065 pgrp = pgfind(-pgid);
1073 * Policy - Don't allow a process to FSETOWN a process
1074 * in another session.
1076 * Remove this test to allow maximum flexibility or
1077 * restrict FSETOWN to the current process or process
1078 * group for maximum safety.
1080 if (pgrp->pg_session != curthread->td_proc->p_session) {
1091 * Since funsetownlst() is called without the proctree
1092 * locked, we need to check for P_WEXIT.
1093 * XXX: is ESRCH correct?
1095 if ((proc->p_flag & P_WEXIT) != 0) {
1100 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
1101 sigio->sio_proc = proc;
1105 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
1106 sigio->sio_pgrp = pgrp;
1109 sx_sunlock(&proctree_lock);
1116 sx_sunlock(&proctree_lock);
1117 crfree(sigio->sio_ucred);
1118 free(sigio, M_SIGIO);
1123 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
1127 struct sigio **sigiop;
1132 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0;
1138 * Function drops the filedesc lock on return.
1141 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1146 FILEDESC_XLOCK_ASSERT(fdp);
1149 if (td->td_proc->p_fdtol != NULL) {
1151 * Ask fdfree() to sleep to ensure that all relevant
1152 * process leaders can be traversed in closef().
1154 fdp->fd_holdleaderscount++;
1161 * We now hold the fp reference that used to be owned by the
1162 * descriptor array. We have to unlock the FILEDESC *AFTER*
1163 * knote_fdclose to prevent a race of the fd getting opened, a knote
1164 * added, and deleteing a knote for the new fd.
1166 knote_fdclose(td, fd);
1169 * We need to notify mqueue if the object is of type mqueue.
1171 if (fp->f_type == DTYPE_MQUEUE)
1172 mq_fdclose(td, fd, fp);
1173 FILEDESC_XUNLOCK(fdp);
1175 error = closef(fp, td);
1177 FILEDESC_XLOCK(fdp);
1178 fdp->fd_holdleaderscount--;
1179 if (fdp->fd_holdleaderscount == 0 &&
1180 fdp->fd_holdleaderswakeup != 0) {
1181 fdp->fd_holdleaderswakeup = 0;
1182 wakeup(&fdp->fd_holdleaderscount);
1184 FILEDESC_XUNLOCK(fdp);
1190 * Close a file descriptor.
1192 #ifndef _SYS_SYSPROTO_H_
1201 struct close_args *uap;
1204 return (kern_close(td, uap->fd));
1212 struct filedesc *fdp;
1215 fdp = td->td_proc->p_fd;
1217 AUDIT_SYSCLOSE(td, fd);
1219 FILEDESC_XLOCK(fdp);
1220 if ((fp = fget_locked(fdp, fd)) == NULL) {
1221 FILEDESC_XUNLOCK(fdp);
1226 /* closefp() drops the FILEDESC lock for us. */
1227 return (closefp(fdp, fd, fp, td, 1));
1231 * Close open file descriptors.
1233 #ifndef _SYS_SYSPROTO_H_
1234 struct closefrom_args {
1240 sys_closefrom(struct thread *td, struct closefrom_args *uap)
1242 struct filedesc *fdp;
1245 fdp = td->td_proc->p_fd;
1246 AUDIT_ARG_FD(uap->lowfd);
1249 * Treat negative starting file descriptor values identical to
1250 * closefrom(0) which closes all files.
1254 FILEDESC_SLOCK(fdp);
1255 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) {
1256 if (fdp->fd_ofiles[fd].fde_file != NULL) {
1257 FILEDESC_SUNLOCK(fdp);
1258 (void)kern_close(td, fd);
1259 FILEDESC_SLOCK(fdp);
1262 FILEDESC_SUNLOCK(fdp);
1266 #if defined(COMPAT_43)
1268 * Return status information about a file descriptor.
1270 #ifndef _SYS_SYSPROTO_H_
1271 struct ofstat_args {
1278 ofstat(struct thread *td, struct ofstat_args *uap)
1284 error = kern_fstat(td, uap->fd, &ub);
1287 error = copyout(&oub, uap->sb, sizeof(oub));
1291 #endif /* COMPAT_43 */
1294 * Return status information about a file descriptor.
1296 #ifndef _SYS_SYSPROTO_H_
1304 sys_fstat(struct thread *td, struct fstat_args *uap)
1309 error = kern_fstat(td, uap->fd, &ub);
1311 error = copyout(&ub, uap->sb, sizeof(ub));
1316 kern_fstat(struct thread *td, int fd, struct stat *sbp)
1319 cap_rights_t rights;
1324 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp);
1328 AUDIT_ARG_FILE(td->td_proc, fp);
1330 error = fo_stat(fp, sbp, td->td_ucred, td);
1333 if (error == 0 && KTRPOINT(td, KTR_STRUCT))
1340 * Return status information about a file descriptor.
1342 #ifndef _SYS_SYSPROTO_H_
1343 struct nfstat_args {
1350 sys_nfstat(struct thread *td, struct nfstat_args *uap)
1356 error = kern_fstat(td, uap->fd, &ub);
1358 cvtnstat(&ub, &nub);
1359 error = copyout(&nub, uap->sb, sizeof(nub));
1365 * Return pathconf information about a file descriptor.
1367 #ifndef _SYS_SYSPROTO_H_
1368 struct fpathconf_args {
1375 sys_fpathconf(struct thread *td, struct fpathconf_args *uap)
1379 cap_rights_t rights;
1382 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp);
1386 /* If asynchronous I/O is available, it works for all descriptors. */
1387 if (uap->name == _PC_ASYNC_IO) {
1388 td->td_retval[0] = async_io_version;
1393 vn_lock(vp, LK_SHARED | LK_RETRY);
1394 error = VOP_PATHCONF(vp, uap->name, td->td_retval);
1396 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
1397 if (uap->name != _PC_PIPE_BUF) {
1400 td->td_retval[0] = PIPE_BUF;
1412 * Initialize filecaps structure.
1415 filecaps_init(struct filecaps *fcaps)
1418 bzero(fcaps, sizeof(*fcaps));
1419 fcaps->fc_nioctls = -1;
1423 * Copy filecaps structure allocating memory for ioctls array if needed.
1426 filecaps_copy(const struct filecaps *src, struct filecaps *dst)
1431 if (src->fc_ioctls != NULL) {
1432 KASSERT(src->fc_nioctls > 0,
1433 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1435 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1436 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1437 bcopy(src->fc_ioctls, dst->fc_ioctls, size);
1442 * Move filecaps structure to the new place and clear the old place.
1445 filecaps_move(struct filecaps *src, struct filecaps *dst)
1449 bzero(src, sizeof(*src));
1453 * Fill the given filecaps structure with full rights.
1456 filecaps_fill(struct filecaps *fcaps)
1459 CAP_ALL(&fcaps->fc_rights);
1460 fcaps->fc_ioctls = NULL;
1461 fcaps->fc_nioctls = -1;
1462 fcaps->fc_fcntls = CAP_FCNTL_ALL;
1466 * Free memory allocated within filecaps structure.
1469 filecaps_free(struct filecaps *fcaps)
1472 free(fcaps->fc_ioctls, M_FILECAPS);
1473 bzero(fcaps, sizeof(*fcaps));
1477 * Validate the given filecaps structure.
1480 filecaps_validate(const struct filecaps *fcaps, const char *func)
1483 KASSERT(cap_rights_is_valid(&fcaps->fc_rights),
1484 ("%s: invalid rights", func));
1485 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0,
1486 ("%s: invalid fcntls", func));
1487 KASSERT(fcaps->fc_fcntls == 0 ||
1488 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL),
1489 ("%s: fcntls without CAP_FCNTL", func));
1490 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 :
1491 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0),
1492 ("%s: invalid ioctls", func));
1493 KASSERT(fcaps->fc_nioctls == 0 ||
1494 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL),
1495 ("%s: ioctls without CAP_IOCTL", func));
1499 fdgrowtable_exp(struct filedesc *fdp, int nfd)
1503 FILEDESC_XLOCK_ASSERT(fdp);
1505 nfd1 = fdp->fd_nfiles * 2;
1508 fdgrowtable(fdp, nfd1);
1512 * Grow the file table to accomodate (at least) nfd descriptors.
1515 fdgrowtable(struct filedesc *fdp, int nfd)
1517 struct filedesc0 *fdp0;
1518 struct freetable *ft;
1519 struct filedescent *ntable;
1520 struct filedescent *otable;
1521 int nnfiles, onfiles;
1522 NDSLOTTYPE *nmap, *omap;
1524 FILEDESC_XLOCK_ASSERT(fdp);
1526 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table"));
1528 /* save old values */
1529 onfiles = fdp->fd_nfiles;
1530 otable = fdp->fd_ofiles;
1533 /* compute the size of the new table */
1534 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
1535 if (nnfiles <= onfiles)
1536 /* the table is already large enough */
1540 * Allocate a new table. We need enough space for the
1541 * file entries themselves and the struct freetable we will use
1542 * when we decommission the table and place it on the freelist.
1543 * We place the struct freetable in the middle so we don't have
1544 * to worry about padding.
1546 ntable = malloc(nnfiles * sizeof(ntable[0]) + sizeof(struct freetable),
1547 M_FILEDESC, M_ZERO | M_WAITOK);
1548 /* copy the old data over and point at the new tables */
1549 memcpy(ntable, otable, onfiles * sizeof(*otable));
1550 fdp->fd_ofiles = ntable;
1553 * Allocate a new map only if the old is not large enough. It will
1554 * grow at a slower rate than the table as it can map more
1555 * entries than the table can hold.
1557 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
1558 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC,
1560 /* copy over the old data and update the pointer */
1561 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap));
1566 * In order to have a valid pattern for fget_unlocked()
1567 * fdp->fd_nfiles must be the last member to be updated, otherwise
1568 * fget_unlocked() consumers may reference a new, higher value for
1569 * fdp->fd_nfiles before to access the fdp->fd_ofiles array,
1570 * resulting in OOB accesses.
1572 atomic_store_rel_int(&fdp->fd_nfiles, nnfiles);
1575 * Do not free the old file table, as some threads may still
1576 * reference entries within it. Instead, place it on a freelist
1577 * which will be processed when the struct filedesc is released.
1579 * Note that if onfiles == NDFILE, we're dealing with the original
1580 * static allocation contained within (struct filedesc0 *)fdp,
1581 * which must not be freed.
1583 if (onfiles > NDFILE) {
1584 ft = (struct freetable *)&otable[onfiles];
1585 fdp0 = (struct filedesc0 *)fdp;
1586 ft->ft_table = otable;
1587 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next);
1590 * The map does not have the same possibility of threads still
1591 * holding references to it. So always free it as long as it
1592 * does not reference the original static allocation.
1594 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
1595 free(omap, M_FILEDESC);
1599 * Allocate a file descriptor for the process.
1602 fdalloc(struct thread *td, int minfd, int *result)
1604 struct proc *p = td->td_proc;
1605 struct filedesc *fdp = p->p_fd;
1606 int fd = -1, maxfd, allocfd;
1611 FILEDESC_XLOCK_ASSERT(fdp);
1613 if (fdp->fd_freefile > minfd)
1614 minfd = fdp->fd_freefile;
1616 maxfd = getmaxfd(p);
1619 * Search the bitmap for a free descriptor starting at minfd.
1620 * If none is found, grow the file table.
1622 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
1625 if (fd >= fdp->fd_nfiles) {
1626 allocfd = min(fd * 2, maxfd);
1629 error = racct_set(p, RACCT_NOFILE, allocfd);
1635 * fd is already equal to first free descriptor >= minfd, so
1636 * we only need to grow the table and we are done.
1638 fdgrowtable_exp(fdp, allocfd);
1642 * Perform some sanity checks, then mark the file descriptor as
1643 * used and return it to the caller.
1645 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles),
1646 ("invalid descriptor %d", fd));
1647 KASSERT(!fdisused(fdp, fd),
1648 ("fd_first_free() returned non-free descriptor"));
1649 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
1650 ("file descriptor isn't free"));
1651 KASSERT(fdp->fd_ofiles[fd].fde_flags == 0, ("file flags are set"));
1658 * Allocate n file descriptors for the process.
1661 fdallocn(struct thread *td, int minfd, int *fds, int n)
1663 struct proc *p = td->td_proc;
1664 struct filedesc *fdp = p->p_fd;
1667 FILEDESC_XLOCK_ASSERT(fdp);
1669 for (i = 0; i < n; i++)
1670 if (fdalloc(td, 0, &fds[i]) != 0)
1674 for (i--; i >= 0; i--)
1675 fdunused(fdp, fds[i]);
1683 * Create a new open file structure and allocate a file decriptor for the
1684 * process that refers to it. We add one reference to the file for the
1685 * descriptor table and one reference for resultfp. This is to prevent us
1686 * being preempted and the entry in the descriptor table closed after we
1687 * release the FILEDESC lock.
1690 falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags)
1695 error = falloc_noinstall(td, &fp);
1697 return (error); /* no reference held on error */
1699 error = finstall(td, fp, &fd, flags, NULL);
1701 fdrop(fp, td); /* one reference (fp only) */
1705 if (resultfp != NULL)
1706 *resultfp = fp; /* copy out result */
1708 fdrop(fp, td); /* release local reference */
1710 if (resultfd != NULL)
1717 * Create a new open file structure without allocating a file descriptor.
1720 falloc_noinstall(struct thread *td, struct file **resultfp)
1723 int maxuserfiles = maxfiles - (maxfiles / 20);
1724 static struct timeval lastfail;
1727 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__));
1729 if ((openfiles >= maxuserfiles &&
1730 priv_check(td, PRIV_MAXFILES) != 0) ||
1731 openfiles >= maxfiles) {
1732 if (ppsratecheck(&lastfail, &curfail, 1)) {
1733 printf("kern.maxfiles limit exceeded by uid %i, "
1734 "please see tuning(7).\n", td->td_ucred->cr_ruid);
1738 atomic_add_int(&openfiles, 1);
1739 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO);
1740 refcount_init(&fp->f_count, 1);
1741 fp->f_cred = crhold(td->td_ucred);
1742 fp->f_ops = &badfileops;
1748 * Install a file in a file descriptor table.
1751 finstall(struct thread *td, struct file *fp, int *fd, int flags,
1752 struct filecaps *fcaps)
1754 struct filedesc *fdp = td->td_proc->p_fd;
1755 struct filedescent *fde;
1758 KASSERT(fd != NULL, ("%s: fd == NULL", __func__));
1759 KASSERT(fp != NULL, ("%s: fp == NULL", __func__));
1761 filecaps_validate(fcaps, __func__);
1763 FILEDESC_XLOCK(fdp);
1764 if ((error = fdalloc(td, 0, fd))) {
1765 FILEDESC_XUNLOCK(fdp);
1769 fde = &fdp->fd_ofiles[*fd];
1771 seq_write_begin(&fde->fde_seq);
1774 if ((flags & O_CLOEXEC) != 0)
1775 fde->fde_flags |= UF_EXCLOSE;
1777 filecaps_move(fcaps, &fde->fde_caps);
1779 filecaps_fill(&fde->fde_caps);
1781 seq_write_end(&fde->fde_seq);
1783 FILEDESC_XUNLOCK(fdp);
1788 * Build a new filedesc structure from another.
1789 * Copy the current, root, and jail root vnode references.
1792 fdinit(struct filedesc *fdp)
1794 struct filedesc0 *newfdp;
1796 newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO);
1797 FILEDESC_LOCK_INIT(&newfdp->fd_fd);
1799 FILEDESC_SLOCK(fdp);
1800 newfdp->fd_fd.fd_cdir = fdp->fd_cdir;
1801 if (newfdp->fd_fd.fd_cdir)
1802 VREF(newfdp->fd_fd.fd_cdir);
1803 newfdp->fd_fd.fd_rdir = fdp->fd_rdir;
1804 if (newfdp->fd_fd.fd_rdir)
1805 VREF(newfdp->fd_fd.fd_rdir);
1806 newfdp->fd_fd.fd_jdir = fdp->fd_jdir;
1807 if (newfdp->fd_fd.fd_jdir)
1808 VREF(newfdp->fd_fd.fd_jdir);
1809 FILEDESC_SUNLOCK(fdp);
1812 /* Create the file descriptor table. */
1813 newfdp->fd_fd.fd_refcnt = 1;
1814 newfdp->fd_fd.fd_holdcnt = 1;
1815 newfdp->fd_fd.fd_cmask = CMASK;
1816 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles;
1817 newfdp->fd_fd.fd_nfiles = NDFILE;
1818 newfdp->fd_fd.fd_map = newfdp->fd_dmap;
1819 newfdp->fd_fd.fd_lastfile = -1;
1820 return (&newfdp->fd_fd);
1823 static struct filedesc *
1824 fdhold(struct proc *p)
1826 struct filedesc *fdp;
1828 mtx_lock(&fdesc_mtx);
1832 mtx_unlock(&fdesc_mtx);
1837 fddrop(struct filedesc *fdp)
1839 struct filedesc0 *fdp0;
1840 struct freetable *ft;
1843 mtx_lock(&fdesc_mtx);
1844 i = --fdp->fd_holdcnt;
1845 mtx_unlock(&fdesc_mtx);
1849 FILEDESC_LOCK_DESTROY(fdp);
1850 fdp0 = (struct filedesc0 *)fdp;
1851 while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) {
1852 SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next);
1853 free(ft->ft_table, M_FILEDESC);
1855 free(fdp, M_FILEDESC);
1859 * Share a filedesc structure.
1862 fdshare(struct filedesc *fdp)
1865 FILEDESC_XLOCK(fdp);
1867 FILEDESC_XUNLOCK(fdp);
1872 * Unshare a filedesc structure, if necessary by making a copy
1875 fdunshare(struct thread *td)
1877 struct filedesc *tmp;
1878 struct proc *p = td->td_proc;
1880 if (p->p_fd->fd_refcnt == 1)
1883 tmp = fdcopy(p->p_fd);
1889 * Copy a filedesc structure. A NULL pointer in returns a NULL reference,
1890 * this is to ease callers, not catch errors.
1893 fdcopy(struct filedesc *fdp)
1895 struct filedesc *newfdp;
1896 struct filedescent *nfde, *ofde;
1899 /* Certain daemons might not have file descriptors. */
1903 newfdp = fdinit(fdp);
1904 FILEDESC_SLOCK(fdp);
1905 while (fdp->fd_lastfile >= newfdp->fd_nfiles) {
1906 FILEDESC_SUNLOCK(fdp);
1907 FILEDESC_XLOCK(newfdp);
1908 fdgrowtable(newfdp, fdp->fd_lastfile + 1);
1909 FILEDESC_XUNLOCK(newfdp);
1910 FILEDESC_SLOCK(fdp);
1912 /* copy all passable descriptors (i.e. not kqueue) */
1913 newfdp->fd_freefile = -1;
1914 for (i = 0; i <= fdp->fd_lastfile; ++i) {
1915 ofde = &fdp->fd_ofiles[i];
1916 if (fdisused(fdp, i) &&
1917 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) &&
1918 ofde->fde_file->f_ops != &badfileops) {
1919 nfde = &newfdp->fd_ofiles[i];
1921 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps);
1922 fhold(nfde->fde_file);
1923 newfdp->fd_lastfile = i;
1925 if (newfdp->fd_freefile == -1)
1926 newfdp->fd_freefile = i;
1929 newfdp->fd_cmask = fdp->fd_cmask;
1930 FILEDESC_SUNLOCK(fdp);
1931 FILEDESC_XLOCK(newfdp);
1932 for (i = 0; i <= newfdp->fd_lastfile; ++i) {
1933 if (newfdp->fd_ofiles[i].fde_file != NULL)
1936 if (newfdp->fd_freefile == -1)
1937 newfdp->fd_freefile = i;
1938 FILEDESC_XUNLOCK(newfdp);
1943 * Release a filedesc structure.
1946 fdescfree(struct thread *td)
1948 struct filedesc *fdp;
1950 struct filedesc_to_leader *fdtol;
1952 struct vnode *cdir, *jdir, *rdir, *vp;
1955 /* Certain daemons might not have file descriptors. */
1956 fdp = td->td_proc->p_fd;
1961 PROC_LOCK(td->td_proc);
1962 racct_set(td->td_proc, RACCT_NOFILE, 0);
1963 PROC_UNLOCK(td->td_proc);
1966 /* Check for special need to clear POSIX style locks */
1967 fdtol = td->td_proc->p_fdtol;
1968 if (fdtol != NULL) {
1969 FILEDESC_XLOCK(fdp);
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 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
1975 for (i = 0; i <= fdp->fd_lastfile; i++) {
1976 fp = fdp->fd_ofiles[i].fde_file;
1977 if (fp == NULL || fp->f_type != DTYPE_VNODE)
1980 FILEDESC_XUNLOCK(fdp);
1981 lf.l_whence = SEEK_SET;
1984 lf.l_type = F_UNLCK;
1986 (void) VOP_ADVLOCK(vp,
1987 (caddr_t)td->td_proc->p_leader, F_UNLCK,
1989 FILEDESC_XLOCK(fdp);
1994 if (fdtol->fdl_refcount == 1) {
1995 if (fdp->fd_holdleaderscount > 0 &&
1996 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
1998 * close() or do_dup() has cleared a reference
1999 * in a shared file descriptor table.
2001 fdp->fd_holdleaderswakeup = 1;
2002 sx_sleep(&fdp->fd_holdleaderscount,
2003 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
2006 if (fdtol->fdl_holdcount > 0) {
2008 * Ensure that fdtol->fdl_leader remains
2009 * valid in closef().
2011 fdtol->fdl_wakeup = 1;
2012 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK,
2017 fdtol->fdl_refcount--;
2018 if (fdtol->fdl_refcount == 0 &&
2019 fdtol->fdl_holdcount == 0) {
2020 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
2021 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
2024 td->td_proc->p_fdtol = NULL;
2025 FILEDESC_XUNLOCK(fdp);
2027 free(fdtol, M_FILEDESC_TO_LEADER);
2030 mtx_lock(&fdesc_mtx);
2031 td->td_proc->p_fd = NULL;
2032 mtx_unlock(&fdesc_mtx);
2034 FILEDESC_XLOCK(fdp);
2035 i = --fdp->fd_refcnt;
2037 FILEDESC_XUNLOCK(fdp);
2041 cdir = fdp->fd_cdir;
2042 fdp->fd_cdir = NULL;
2043 rdir = fdp->fd_rdir;
2044 fdp->fd_rdir = NULL;
2045 jdir = fdp->fd_jdir;
2046 fdp->fd_jdir = NULL;
2047 FILEDESC_XUNLOCK(fdp);
2049 for (i = 0; i <= fdp->fd_lastfile; i++) {
2050 fp = fdp->fd_ofiles[i].fde_file;
2052 fdfree_last(fdp, i);
2053 (void) closef(fp, td);
2057 if (fdp->fd_nfiles > NDFILE)
2058 free(fdp->fd_ofiles, M_FILEDESC);
2059 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
2060 free(fdp->fd_map, M_FILEDESC);
2073 * For setugid programs, we don't want to people to use that setugidness
2074 * to generate error messages which write to a file which otherwise would
2075 * otherwise be off-limits to the process. We check for filesystems where
2076 * the vnode can change out from under us after execve (like [lin]procfs).
2078 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is
2079 * sufficient. We also don't check for setugidness since we know we are.
2082 is_unsafe(struct file *fp)
2086 if (fp->f_type != DTYPE_VNODE)
2090 return ((vp->v_vflag & VV_PROCDEP) != 0);
2094 * Make this setguid thing safe, if at all possible.
2097 fdsetugidsafety(struct thread *td)
2099 struct filedesc *fdp;
2103 fdp = td->td_proc->p_fd;
2104 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared"));
2105 MPASS(fdp->fd_nfiles >= 3);
2106 for (i = 0; i <= 2; i++) {
2107 fp = fdp->fd_ofiles[i].fde_file;
2108 if (fp != NULL && is_unsafe(fp)) {
2109 FILEDESC_XLOCK(fdp);
2110 knote_fdclose(td, i);
2112 * NULL-out descriptor prior to close to avoid
2113 * a race while close blocks.
2116 FILEDESC_XUNLOCK(fdp);
2117 (void) closef(fp, td);
2123 * If a specific file object occupies a specific file descriptor, close the
2124 * file descriptor entry and drop a reference on the file object. This is a
2125 * convenience function to handle a subsequent error in a function that calls
2126 * falloc() that handles the race that another thread might have closed the
2127 * file descriptor out from under the thread creating the file object.
2130 fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td)
2133 FILEDESC_XLOCK(fdp);
2134 if (fdp->fd_ofiles[idx].fde_file == fp) {
2136 FILEDESC_XUNLOCK(fdp);
2139 FILEDESC_XUNLOCK(fdp);
2143 * Close any files on exec?
2146 fdcloseexec(struct thread *td)
2148 struct filedesc *fdp;
2149 struct filedescent *fde;
2153 fdp = td->td_proc->p_fd;
2154 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared"));
2155 FILEDESC_XLOCK(fdp);
2156 for (i = 0; i <= fdp->fd_lastfile; i++) {
2157 fde = &fdp->fd_ofiles[i];
2159 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE ||
2160 (fde->fde_flags & UF_EXCLOSE))) {
2162 (void) closefp(fdp, i, fp, td, 0);
2163 /* closefp() drops the FILEDESC lock. */
2164 FILEDESC_XLOCK(fdp);
2167 FILEDESC_XUNLOCK(fdp);
2171 * It is unsafe for set[ug]id processes to be started with file
2172 * descriptors 0..2 closed, as these descriptors are given implicit
2173 * significance in the Standard C library. fdcheckstd() will create a
2174 * descriptor referencing /dev/null for each of stdin, stdout, and
2175 * stderr that is not already open.
2178 fdcheckstd(struct thread *td)
2180 struct filedesc *fdp;
2181 register_t retval, save;
2182 int i, error, devnull;
2184 fdp = td->td_proc->p_fd;
2185 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared"));
2188 for (i = 0; i < 3; i++) {
2189 if (fdp->fd_ofiles[i].fde_file != NULL)
2192 save = td->td_retval[0];
2193 error = kern_open(td, "/dev/null", UIO_SYSSPACE,
2195 devnull = td->td_retval[0];
2196 td->td_retval[0] = save;
2199 KASSERT(devnull == i, ("oof, we didn't get our fd"));
2201 error = do_dup(td, DUP_FIXED, devnull, i, &retval);
2210 * Internal form of close. Decrement reference count on file structure.
2211 * Note: td may be NULL when closing a file that was being passed in a
2214 * XXXRW: Giant is not required for the caller, but often will be held; this
2215 * makes it moderately likely the Giant will be recursed in the VFS case.
2218 closef(struct file *fp, struct thread *td)
2222 struct filedesc_to_leader *fdtol;
2223 struct filedesc *fdp;
2226 * POSIX record locking dictates that any close releases ALL
2227 * locks owned by this process. This is handled by setting
2228 * a flag in the unlock to free ONLY locks obeying POSIX
2229 * semantics, and not to free BSD-style file locks.
2230 * If the descriptor was in a message, POSIX-style locks
2231 * aren't passed with the descriptor, and the thread pointer
2232 * will be NULL. Callers should be careful only to pass a
2233 * NULL thread pointer when there really is no owning
2234 * context that might have locks, or the locks will be
2237 if (fp->f_type == DTYPE_VNODE && td != NULL) {
2239 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
2240 lf.l_whence = SEEK_SET;
2243 lf.l_type = F_UNLCK;
2244 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
2245 F_UNLCK, &lf, F_POSIX);
2247 fdtol = td->td_proc->p_fdtol;
2248 if (fdtol != NULL) {
2250 * Handle special case where file descriptor table is
2251 * shared between multiple process leaders.
2253 fdp = td->td_proc->p_fd;
2254 FILEDESC_XLOCK(fdp);
2255 for (fdtol = fdtol->fdl_next;
2256 fdtol != td->td_proc->p_fdtol;
2257 fdtol = fdtol->fdl_next) {
2258 if ((fdtol->fdl_leader->p_flag &
2261 fdtol->fdl_holdcount++;
2262 FILEDESC_XUNLOCK(fdp);
2263 lf.l_whence = SEEK_SET;
2266 lf.l_type = F_UNLCK;
2268 (void) VOP_ADVLOCK(vp,
2269 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf,
2271 FILEDESC_XLOCK(fdp);
2272 fdtol->fdl_holdcount--;
2273 if (fdtol->fdl_holdcount == 0 &&
2274 fdtol->fdl_wakeup != 0) {
2275 fdtol->fdl_wakeup = 0;
2279 FILEDESC_XUNLOCK(fdp);
2282 return (fdrop(fp, td));
2286 * Initialize the file pointer with the specified properties.
2288 * The ops are set with release semantics to be certain that the flags, type,
2289 * and data are visible when ops is. This is to prevent ops methods from being
2290 * called with bad data.
2293 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops)
2298 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
2302 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
2303 int needfcntl, struct file **fpp, cap_rights_t *haverightsp)
2306 struct filedescent fde;
2312 cap_rights_t haverights;
2317 * Avoid reads reordering and then a first access to the
2318 * fdp->fd_ofiles table which could result in OOB operation.
2320 if (fd < 0 || fd >= atomic_load_acq_int(&fdp->fd_nfiles))
2323 * Fetch the descriptor locklessly. We avoid fdrop() races by
2324 * never raising a refcount above 0. To accomplish this we have
2325 * to use a cmpset loop rather than an atomic_add. The descriptor
2326 * must be re-verified once we acquire a reference to be certain
2327 * that the identity is still correct and we did not lose a race
2328 * due to preemption.
2332 seq = seq_read(fd_seq(fdp, fd));
2333 fde = fdp->fd_ofiles[fd];
2334 if (!seq_consistent(fd_seq(fdp, fd), seq)) {
2340 fp = fdp->fd_ofiles[fd].fde_file;
2345 haverights = *cap_rights_fde(&fde);
2346 if (needrightsp != NULL) {
2347 error = cap_check(&haverights, needrightsp);
2350 if (cap_rights_is_set(needrightsp, CAP_FCNTL)) {
2351 error = cap_fcntl_check_fde(&fde, needfcntl);
2357 count = fp->f_count;
2361 * Use an acquire barrier to prevent caching of fd_ofiles
2362 * so it is refreshed for verification.
2364 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1)
2367 if (seq_consistent_nomb(fd_seq(fdp, fd), seq))
2369 if (fp == fdp->fd_ofiles[fd].fde_file)
2372 fdrop(fp, curthread);
2375 if (haverightsp != NULL) {
2377 *haverightsp = haverights;
2379 CAP_ALL(haverightsp);
2386 * Extract the file pointer associated with the specified descriptor for the
2387 * current user process.
2389 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is
2392 * File's rights will be checked against the capability rights mask.
2394 * If an error occured the non-zero error is returned and *fpp is set to
2395 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is
2396 * responsible for fdrop().
2399 _fget(struct thread *td, int fd, struct file **fpp, int flags,
2400 cap_rights_t *needrightsp, u_char *maxprotp)
2402 struct filedesc *fdp;
2404 cap_rights_t haverights, needrights;
2408 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL)
2410 if (needrightsp != NULL)
2411 needrights = *needrightsp;
2413 cap_rights_init(&needrights);
2414 if (maxprotp != NULL)
2415 cap_rights_set(&needrights, CAP_MMAP);
2416 error = fget_unlocked(fdp, fd, &needrights, 0, &fp, &haverights);
2419 if (fp->f_ops == &badfileops) {
2426 * If requested, convert capability rights to access flags.
2428 if (maxprotp != NULL)
2429 *maxprotp = cap_rights_to_vmprot(&haverights);
2430 #else /* !CAPABILITIES */
2431 if (maxprotp != NULL)
2432 *maxprotp = VM_PROT_ALL;
2433 #endif /* CAPABILITIES */
2436 * FREAD and FWRITE failure return EBADF as per POSIX.
2442 if ((fp->f_flag & flags) == 0)
2446 if ((fp->f_flag & (FREAD | FEXEC)) == 0 ||
2447 ((fp->f_flag & FWRITE) != 0))
2453 KASSERT(0, ("wrong flags"));
2466 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
2469 return(_fget(td, fd, fpp, 0, rightsp, NULL));
2473 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp,
2477 return (_fget(td, fd, fpp, 0, rightsp, maxprotp));
2481 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
2484 return(_fget(td, fd, fpp, FREAD, rightsp, NULL));
2488 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
2491 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL));
2495 * Like fget() but loads the underlying vnode, or returns an error if the
2496 * descriptor does not represent a vnode. Note that pipes use vnodes but
2497 * never have VM objects. The returned vnode will be vref()'d.
2499 * XXX: what about the unused flags ?
2502 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp,
2509 error = _fget(td, fd, &fp, flags, needrightsp, NULL);
2512 if (fp->f_vnode == NULL) {
2524 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
2527 return (_fgetvp(td, fd, 0, rightsp, vpp));
2531 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
2532 struct filecaps *havecaps, struct vnode **vpp)
2534 struct filedesc *fdp;
2540 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL)
2543 fp = fget_locked(fdp, fd);
2544 if (fp == NULL || fp->f_ops == &badfileops)
2548 if (needrightsp != NULL) {
2549 error = cap_check(cap_rights(fdp, fd), needrightsp);
2555 if (fp->f_vnode == NULL)
2560 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps);
2566 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
2569 return (_fgetvp(td, fd, FREAD, rightsp, vpp));
2573 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
2576 return (_fgetvp(td, fd, FEXEC, rightsp, vpp));
2581 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
2585 return (_fgetvp(td, fd, FWRITE, rightsp, vpp));
2590 * Like fget() but loads the underlying socket, or returns an error if the
2591 * descriptor does not represent a socket.
2593 * We bump the ref count on the returned socket. XXX Also obtain the SX lock
2596 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely
2597 * on their file descriptor reference to prevent the socket from being free'd
2601 fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp,
2610 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0)
2612 if (fp->f_type != DTYPE_SOCKET) {
2617 *fflagp = fp->f_flag;
2628 * Drop the reference count on the socket and XXX release the SX lock in the
2629 * future. The last reference closes the socket.
2631 * Note: fputsock() is deprecated, see comment for fgetsock().
2634 fputsock(struct socket *so)
2639 CURVNET_SET(so->so_vnet);
2645 * Handle the last reference to a file being closed.
2648 _fdrop(struct file *fp, struct thread *td)
2653 if (fp->f_count != 0)
2654 panic("fdrop: count %d", fp->f_count);
2655 if (fp->f_ops != &badfileops)
2656 error = fo_close(fp, td);
2657 atomic_subtract_int(&openfiles, 1);
2659 free(fp->f_advice, M_FADVISE);
2660 uma_zfree(file_zone, fp);
2666 * Apply an advisory lock on a file descriptor.
2668 * Just attempt to get a record lock of the requested type on the entire file
2669 * (l_whence = SEEK_SET, l_start = 0, l_len = 0).
2671 #ifndef _SYS_SYSPROTO_H_
2679 sys_flock(struct thread *td, struct flock_args *uap)
2684 cap_rights_t rights;
2687 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp);
2690 if (fp->f_type != DTYPE_VNODE) {
2692 return (EOPNOTSUPP);
2696 lf.l_whence = SEEK_SET;
2699 if (uap->how & LOCK_UN) {
2700 lf.l_type = F_UNLCK;
2701 atomic_clear_int(&fp->f_flag, FHASLOCK);
2702 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
2705 if (uap->how & LOCK_EX)
2706 lf.l_type = F_WRLCK;
2707 else if (uap->how & LOCK_SH)
2708 lf.l_type = F_RDLCK;
2713 atomic_set_int(&fp->f_flag, FHASLOCK);
2714 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
2715 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
2721 * Duplicate the specified descriptor to a free descriptor.
2724 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
2725 int openerror, int *indxp)
2727 struct filedescent *newfde, *oldfde;
2731 KASSERT(openerror == ENODEV || openerror == ENXIO,
2732 ("unexpected error %d in %s", openerror, __func__));
2735 * If the to-be-dup'd fd number is greater than the allowed number
2736 * of file descriptors, or the fd to be dup'd has already been
2737 * closed, then reject.
2739 FILEDESC_XLOCK(fdp);
2740 if ((fp = fget_locked(fdp, dfd)) == NULL) {
2741 FILEDESC_XUNLOCK(fdp);
2745 error = fdalloc(td, 0, &indx);
2747 FILEDESC_XUNLOCK(fdp);
2752 * There are two cases of interest here.
2754 * For ENODEV simply dup (dfd) to file descriptor (indx) and return.
2756 * For ENXIO steal away the file structure from (dfd) and store it in
2757 * (indx). (dfd) is effectively closed by this operation.
2759 switch (openerror) {
2762 * Check that the mode the file is being opened for is a
2763 * subset of the mode of the existing descriptor.
2765 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) {
2766 fdunused(fdp, indx);
2767 FILEDESC_XUNLOCK(fdp);
2771 newfde = &fdp->fd_ofiles[indx];
2772 oldfde = &fdp->fd_ofiles[dfd];
2774 seq_write_begin(&newfde->fde_seq);
2776 memcpy(newfde, oldfde, fde_change_size);
2777 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps);
2779 seq_write_end(&newfde->fde_seq);
2784 * Steal away the file pointer from dfd and stuff it into indx.
2786 newfde = &fdp->fd_ofiles[indx];
2787 oldfde = &fdp->fd_ofiles[dfd];
2789 seq_write_begin(&newfde->fde_seq);
2791 memcpy(newfde, oldfde, fde_change_size);
2792 bzero(oldfde, fde_change_size);
2795 seq_write_end(&newfde->fde_seq);
2799 FILEDESC_XUNLOCK(fdp);
2805 * Scan all active processes and prisons to see if any of them have a current
2806 * or root directory of `olddp'. If so, replace them with the new mount point.
2809 mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
2811 struct filedesc *fdp;
2816 if (vrefcnt(olddp) == 1)
2819 sx_slock(&allproc_lock);
2820 FOREACH_PROC_IN_SYSTEM(p) {
2824 FILEDESC_XLOCK(fdp);
2825 if (fdp->fd_cdir == olddp) {
2827 fdp->fd_cdir = newdp;
2830 if (fdp->fd_rdir == olddp) {
2832 fdp->fd_rdir = newdp;
2835 if (fdp->fd_jdir == olddp) {
2837 fdp->fd_jdir = newdp;
2840 FILEDESC_XUNLOCK(fdp);
2843 sx_sunlock(&allproc_lock);
2844 if (rootvnode == olddp) {
2849 mtx_lock(&prison0.pr_mtx);
2850 if (prison0.pr_root == olddp) {
2852 prison0.pr_root = newdp;
2855 mtx_unlock(&prison0.pr_mtx);
2856 sx_slock(&allprison_lock);
2857 TAILQ_FOREACH(pr, &allprison, pr_list) {
2858 mtx_lock(&pr->pr_mtx);
2859 if (pr->pr_root == olddp) {
2861 pr->pr_root = newdp;
2864 mtx_unlock(&pr->pr_mtx);
2866 sx_sunlock(&allprison_lock);
2871 struct filedesc_to_leader *
2872 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader)
2874 struct filedesc_to_leader *fdtol;
2876 fdtol = malloc(sizeof(struct filedesc_to_leader),
2877 M_FILEDESC_TO_LEADER,
2879 fdtol->fdl_refcount = 1;
2880 fdtol->fdl_holdcount = 0;
2881 fdtol->fdl_wakeup = 0;
2882 fdtol->fdl_leader = leader;
2884 FILEDESC_XLOCK(fdp);
2885 fdtol->fdl_next = old->fdl_next;
2886 fdtol->fdl_prev = old;
2887 old->fdl_next = fdtol;
2888 fdtol->fdl_next->fdl_prev = fdtol;
2889 FILEDESC_XUNLOCK(fdp);
2891 fdtol->fdl_next = fdtol;
2892 fdtol->fdl_prev = fdtol;
2898 * Get file structures globally.
2901 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
2904 struct filedesc *fdp;
2909 error = sysctl_wire_old_buffer(req, 0);
2912 if (req->oldptr == NULL) {
2914 sx_slock(&allproc_lock);
2915 FOREACH_PROC_IN_SYSTEM(p) {
2916 if (p->p_state == PRS_NEW)
2921 /* overestimates sparse tables. */
2922 if (fdp->fd_lastfile > 0)
2923 n += fdp->fd_lastfile;
2926 sx_sunlock(&allproc_lock);
2927 return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
2930 bzero(&xf, sizeof(xf));
2931 xf.xf_size = sizeof(xf);
2932 sx_slock(&allproc_lock);
2933 FOREACH_PROC_IN_SYSTEM(p) {
2935 if (p->p_state == PRS_NEW) {
2939 if (p_cansee(req->td, p) != 0) {
2943 xf.xf_pid = p->p_pid;
2944 xf.xf_uid = p->p_ucred->cr_uid;
2949 FILEDESC_SLOCK(fdp);
2950 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) {
2951 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
2955 xf.xf_data = fp->f_data;
2956 xf.xf_vnode = fp->f_vnode;
2957 xf.xf_type = fp->f_type;
2958 xf.xf_count = fp->f_count;
2960 xf.xf_offset = foffset_get(fp);
2961 xf.xf_flag = fp->f_flag;
2962 error = SYSCTL_OUT(req, &xf, sizeof(xf));
2966 FILEDESC_SUNLOCK(fdp);
2971 sx_sunlock(&allproc_lock);
2975 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
2976 0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
2978 #ifdef KINFO_FILE_SIZE
2979 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
2983 xlate_fflags(int fflags)
2985 static const struct {
2988 } fflags_table[] = {
2989 { FAPPEND, KF_FLAG_APPEND },
2990 { FASYNC, KF_FLAG_ASYNC },
2991 { FFSYNC, KF_FLAG_FSYNC },
2992 { FHASLOCK, KF_FLAG_HASLOCK },
2993 { FNONBLOCK, KF_FLAG_NONBLOCK },
2994 { FREAD, KF_FLAG_READ },
2995 { FWRITE, KF_FLAG_WRITE },
2996 { O_CREAT, KF_FLAG_CREAT },
2997 { O_DIRECT, KF_FLAG_DIRECT },
2998 { O_EXCL, KF_FLAG_EXCL },
2999 { O_EXEC, KF_FLAG_EXEC },
3000 { O_EXLOCK, KF_FLAG_EXLOCK },
3001 { O_NOFOLLOW, KF_FLAG_NOFOLLOW },
3002 { O_SHLOCK, KF_FLAG_SHLOCK },
3003 { O_TRUNC, KF_FLAG_TRUNC }
3009 for (i = 0; i < nitems(fflags_table); i++)
3010 if (fflags & fflags_table[i].fflag)
3011 kflags |= fflags_table[i].kf_fflag;
3015 /* Trim unused data from kf_path by truncating the structure size. */
3017 pack_kinfo(struct kinfo_file *kif)
3020 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
3021 strlen(kif->kf_path) + 1;
3022 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
3026 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp,
3027 struct kinfo_file *kif, struct filedesc *fdp)
3031 bzero(kif, sizeof(*kif));
3033 /* Set a default type to allow for empty fill_kinfo() methods. */
3034 kif->kf_type = KF_TYPE_UNKNOWN;
3035 kif->kf_flags = xlate_fflags(fp->f_flag);
3036 if (rightsp != NULL)
3037 kif->kf_cap_rights = *rightsp;
3039 cap_rights_init(&kif->kf_cap_rights);
3041 kif->kf_ref_count = fp->f_count;
3042 kif->kf_offset = foffset_get(fp);
3045 * This may drop the filedesc lock, so the 'fp' cannot be
3046 * accessed after this call.
3048 error = fo_fill_kinfo(fp, kif, fdp);
3050 kif->kf_status |= KF_ATTR_VALID;
3055 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags,
3056 struct kinfo_file *kif)
3060 bzero(kif, sizeof(*kif));
3062 kif->kf_type = KF_TYPE_VNODE;
3063 error = vn_fill_kinfo_vnode(vp, kif);
3065 kif->kf_status |= KF_ATTR_VALID;
3066 kif->kf_flags = xlate_fflags(fflags);
3068 kif->kf_ref_count = -1;
3069 kif->kf_offset = -1;
3074 struct export_fd_buf {
3075 struct filedesc *fdp;
3078 struct kinfo_file kif;
3082 export_kinfo_to_sb(struct export_fd_buf *efbuf)
3084 struct kinfo_file *kif;
3087 if (efbuf->remainder != -1) {
3088 if (efbuf->remainder < kif->kf_structsize) {
3089 /* Terminate export. */
3090 efbuf->remainder = 0;
3093 efbuf->remainder -= kif->kf_structsize;
3095 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM);
3099 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp,
3100 struct export_fd_buf *efbuf)
3104 if (efbuf->remainder == 0)
3106 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp);
3107 FILEDESC_SUNLOCK(efbuf->fdp);
3108 error = export_kinfo_to_sb(efbuf);
3109 FILEDESC_SLOCK(efbuf->fdp);
3114 export_vnode_to_sb(struct vnode *vp, int fd, int fflags,
3115 struct export_fd_buf *efbuf)
3119 if (efbuf->remainder == 0)
3121 if (efbuf->fdp != NULL)
3122 FILEDESC_SUNLOCK(efbuf->fdp);
3123 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif);
3124 error = export_kinfo_to_sb(efbuf);
3125 if (efbuf->fdp != NULL)
3126 FILEDESC_SLOCK(efbuf->fdp);
3131 * Store a process file descriptor information to sbuf.
3133 * Takes a locked proc as argument, and returns with the proc unlocked.
3136 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen)
3139 struct filedesc *fdp;
3140 struct export_fd_buf *efbuf;
3141 struct vnode *cttyvp, *textvp, *tracevp;
3143 cap_rights_t rights;
3145 PROC_LOCK_ASSERT(p, MA_OWNED);
3148 tracevp = p->p_tracevp;
3149 if (tracevp != NULL)
3152 textvp = p->p_textvp;
3155 /* Controlling tty. */
3157 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) {
3158 cttyvp = p->p_pgrp->pg_session->s_ttyvp;
3164 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
3167 efbuf->remainder = maxlen;
3168 if (tracevp != NULL)
3169 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE,
3172 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf);
3174 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE,
3180 FILEDESC_SLOCK(fdp);
3181 /* working directory */
3182 if (fdp->fd_cdir != NULL) {
3184 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf);
3186 /* root directory */
3187 if (fdp->fd_rdir != NULL) {
3189 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf);
3191 /* jail directory */
3192 if (fdp->fd_jdir != NULL) {
3194 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf);
3196 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) {
3197 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
3200 rights = *cap_rights(fdp, i);
3201 #else /* !CAPABILITIES */
3202 cap_rights_init(&rights);
3205 * Create sysctl entry. It is OK to drop the filedesc
3206 * lock inside of export_file_to_sb() as we will
3207 * re-validate and re-evaluate its properties when the
3210 error = export_file_to_sb(fp, i, &rights, efbuf);
3211 if (error != 0 || efbuf->remainder == 0)
3214 FILEDESC_SUNLOCK(fdp);
3217 free(efbuf, M_TEMP);
3221 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5)
3224 * Get per-process file descriptors for use by procstat(1), et al.
3227 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
3232 int error, error2, *name;
3236 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req);
3237 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
3242 maxlen = req->oldptr != NULL ? req->oldlen : -1;
3243 error = kern_proc_filedesc_out(p, &sb, maxlen);
3244 error2 = sbuf_finish(&sb);
3246 return (error != 0 ? error : error2);
3249 #ifdef KINFO_OFILE_SIZE
3250 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
3253 #ifdef COMPAT_FREEBSD7
3255 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif)
3258 okif->kf_structsize = sizeof(*okif);
3259 okif->kf_type = kif->kf_type;
3260 okif->kf_fd = kif->kf_fd;
3261 okif->kf_ref_count = kif->kf_ref_count;
3262 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE |
3263 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK |
3264 KF_FLAG_DIRECT | KF_FLAG_HASLOCK);
3265 okif->kf_offset = kif->kf_offset;
3266 okif->kf_vnode_type = kif->kf_vnode_type;
3267 okif->kf_sock_domain = kif->kf_sock_domain;
3268 okif->kf_sock_type = kif->kf_sock_type;
3269 okif->kf_sock_protocol = kif->kf_sock_protocol;
3270 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path));
3271 okif->kf_sa_local = kif->kf_sa_local;
3272 okif->kf_sa_peer = kif->kf_sa_peer;
3276 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif,
3277 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req)
3282 FILEDESC_SUNLOCK(fdp);
3283 export_vnode_to_kinfo(vp, type, 0, kif);
3284 kinfo_to_okinfo(kif, okif);
3285 error = SYSCTL_OUT(req, okif, sizeof(*okif));
3286 FILEDESC_SLOCK(fdp);
3291 * Get per-process file descriptors for use by procstat(1), et al.
3294 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
3296 struct kinfo_ofile *okif;
3297 struct kinfo_file *kif;
3298 struct filedesc *fdp;
3299 int error, i, *name;
3304 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
3311 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
3312 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK);
3313 FILEDESC_SLOCK(fdp);
3314 if (fdp->fd_cdir != NULL)
3315 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif,
3317 if (fdp->fd_rdir != NULL)
3318 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif,
3320 if (fdp->fd_jdir != NULL)
3321 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif,
3323 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) {
3324 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
3326 export_file_to_kinfo(fp, i, NULL, kif, fdp);
3327 FILEDESC_SUNLOCK(fdp);
3328 kinfo_to_okinfo(kif, okif);
3329 error = SYSCTL_OUT(req, okif, sizeof(*okif));
3330 FILEDESC_SLOCK(fdp);
3334 FILEDESC_SUNLOCK(fdp);
3341 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc,
3342 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc,
3343 "Process ofiledesc entries");
3344 #endif /* COMPAT_FREEBSD7 */
3347 vntype_to_kinfo(int vtype)
3352 } vtypes_table[] = {
3353 { VBAD, KF_VTYPE_VBAD },
3354 { VBLK, KF_VTYPE_VBLK },
3355 { VCHR, KF_VTYPE_VCHR },
3356 { VDIR, KF_VTYPE_VDIR },
3357 { VFIFO, KF_VTYPE_VFIFO },
3358 { VLNK, KF_VTYPE_VLNK },
3359 { VNON, KF_VTYPE_VNON },
3360 { VREG, KF_VTYPE_VREG },
3361 { VSOCK, KF_VTYPE_VSOCK }
3366 * Perform vtype translation.
3368 for (i = 0; i < nitems(vtypes_table); i++)
3369 if (vtypes_table[i].vtype == vtype)
3370 return (vtypes_table[i].kf_vtype);
3372 return (KF_VTYPE_UNKNOWN);
3375 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc,
3376 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc,
3377 "Process filedesc entries");
3381 * For the purposes of debugging, generate a human-readable string for the
3385 file_type_to_name(short type)
3415 * For the purposes of debugging, identify a process (if any, perhaps one of
3416 * many) that references the passed file in its file descriptor array. Return
3419 static struct proc *
3420 file_to_first_proc(struct file *fp)
3422 struct filedesc *fdp;
3426 FOREACH_PROC_IN_SYSTEM(p) {
3427 if (p->p_state == PRS_NEW)
3432 for (n = 0; n <= fdp->fd_lastfile; n++) {
3433 if (fp == fdp->fd_ofiles[n].fde_file)
3441 db_print_file(struct file *fp, int header)
3446 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n",
3447 "File", "Type", "Data", "Flag", "GCFl", "Count",
3448 "MCount", "Vnode", "FPID", "FCmd");
3449 p = file_to_first_proc(fp);
3450 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp,
3451 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag,
3452 0, fp->f_count, 0, fp->f_vnode,
3453 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
3456 DB_SHOW_COMMAND(file, db_show_file)
3461 db_printf("usage: show file <addr>\n");
3464 fp = (struct file *)addr;
3465 db_print_file(fp, 1);
3468 DB_SHOW_COMMAND(files, db_show_files)
3470 struct filedesc *fdp;
3477 FOREACH_PROC_IN_SYSTEM(p) {
3478 if (p->p_state == PRS_NEW)
3480 if ((fdp = p->p_fd) == NULL)
3482 for (n = 0; n <= fdp->fd_lastfile; ++n) {
3483 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
3485 db_print_file(fp, header);
3492 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
3493 &maxfilesperproc, 0, "Maximum files allowed open per process");
3495 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
3496 &maxfiles, 0, "Maximum number of files");
3498 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
3499 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files");
3503 filelistinit(void *dummy)
3506 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
3507 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
3508 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
3509 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF);
3511 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
3513 /*-------------------------------------------------------------------*/
3516 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred,
3517 int flags, struct thread *td)
3524 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
3532 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
3540 badfo_poll(struct file *fp, int events, struct ucred *active_cred,
3548 badfo_kqfilter(struct file *fp, struct knote *kn)
3555 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
3563 badfo_close(struct file *fp, struct thread *td)
3570 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
3578 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
3586 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
3587 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
3588 int kflags, struct sendfile_sync *sfs, struct thread *td)
3595 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
3601 struct fileops badfileops = {
3602 .fo_read = badfo_readwrite,
3603 .fo_write = badfo_readwrite,
3604 .fo_truncate = badfo_truncate,
3605 .fo_ioctl = badfo_ioctl,
3606 .fo_poll = badfo_poll,
3607 .fo_kqfilter = badfo_kqfilter,
3608 .fo_stat = badfo_stat,
3609 .fo_close = badfo_close,
3610 .fo_chmod = badfo_chmod,
3611 .fo_chown = badfo_chown,
3612 .fo_sendfile = badfo_sendfile,
3613 .fo_fill_kinfo = badfo_fill_kinfo,
3617 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred,
3618 int flags, struct thread *td)
3621 return (EOPNOTSUPP);
3625 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
3633 invfo_ioctl(struct file *fp, u_long com, void *data,
3634 struct ucred *active_cred, struct thread *td)
3641 invfo_poll(struct file *fp, int events, struct ucred *active_cred,
3645 return (poll_no_poll(events));
3649 invfo_kqfilter(struct file *fp, struct knote *kn)
3656 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
3664 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
3672 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
3673 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
3674 int kflags, struct sendfile_sync *sfs, struct thread *td)
3680 /*-------------------------------------------------------------------*/
3683 * File Descriptor pseudo-device driver (/dev/fd/).
3685 * Opening minor device N dup()s the file (if any) connected to file
3686 * descriptor N belonging to the calling process. Note that this driver
3687 * consists of only the ``open()'' routine, because all subsequent
3688 * references to this file will be direct to the other driver.
3690 * XXX: we could give this one a cloning event handler if necessary.
3695 fdopen(struct cdev *dev, int mode, int type, struct thread *td)
3699 * XXX Kludge: set curthread->td_dupfd to contain the value of the
3700 * the file descriptor being sought for duplication. The error
3701 * return ensures that the vnode for this device will be released
3702 * by vn_open. Open will detect this special error and take the
3703 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
3704 * will simply report the error.
3706 td->td_dupfd = dev2unit(dev);
3710 static struct cdevsw fildesc_cdevsw = {
3711 .d_version = D_VERSION,
3717 fildesc_drvinit(void *unused)
3721 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
3722 UID_ROOT, GID_WHEEL, 0666, "fd/0");
3723 make_dev_alias(dev, "stdin");
3724 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
3725 UID_ROOT, GID_WHEEL, 0666, "fd/1");
3726 make_dev_alias(dev, "stdout");
3727 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
3728 UID_ROOT, GID_WHEEL, 0666, "fd/2");
3729 make_dev_alias(dev, "stderr");
3732 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);