diff --git a/sys/fs/fifofs/fifo_vnops.c b/sys/fs/fifofs/fifo_vnops.c index 861f1b40a744..1b941620b080 100644 --- a/sys/fs/fifofs/fifo_vnops.c +++ b/sys/fs/fifofs/fifo_vnops.c @@ -1,380 +1,382 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1990, 1993, 1995 * The Regents of the University of California. * Copyright (c) 2005 Robert N. M. Watson * Copyright (c) 2012 Giovanni Trematerra * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)fifo_vnops.c 8.10 (Berkeley) 5/27/95 * $FreeBSD$ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * This structure is associated with the FIFO vnode and stores * the state associated with the FIFO. * Notes about locking: * - fi_pipe is invariant since init time. * - fi_readers and fi_writers are protected by the vnode lock. */ struct fifoinfo { struct pipe *fi_pipe; long fi_readers; long fi_writers; u_int fi_rgen; u_int fi_wgen; }; static vop_print_t fifo_print; static vop_open_t fifo_open; static vop_close_t fifo_close; static vop_advlock_t fifo_advlock; struct vop_vector fifo_specops = { .vop_default = &default_vnodeops, .vop_advlock = fifo_advlock, .vop_close = fifo_close, .vop_create = VOP_PANIC, .vop_getattr = VOP_EBADF, .vop_ioctl = VOP_PANIC, .vop_kqfilter = VOP_PANIC, .vop_link = VOP_PANIC, .vop_mkdir = VOP_PANIC, .vop_mknod = VOP_PANIC, .vop_open = fifo_open, .vop_pathconf = VOP_PANIC, .vop_print = fifo_print, .vop_read = VOP_PANIC, .vop_readdir = VOP_PANIC, .vop_readlink = VOP_PANIC, .vop_reallocblks = VOP_PANIC, .vop_reclaim = VOP_NULL, .vop_remove = VOP_PANIC, .vop_rename = VOP_PANIC, .vop_rmdir = VOP_PANIC, .vop_setattr = VOP_EBADF, .vop_symlink = VOP_PANIC, .vop_write = VOP_PANIC, }; VFS_VOP_VECTOR_REGISTER(fifo_specops); /* * Dispose of fifo resources. */ static void fifo_cleanup(struct vnode *vp) { struct fifoinfo *fip; ASSERT_VOP_ELOCKED(vp, "fifo_cleanup"); fip = vp->v_fifoinfo; if (fip->fi_readers == 0 && fip->fi_writers == 0) { vp->v_fifoinfo = NULL; pipe_dtor(fip->fi_pipe); free(fip, M_VNODE); } } /* * Open called to set up a new instance of a fifo or * to find an active instance of a fifo. */ /* ARGSUSED */ static int fifo_open(ap) struct vop_open_args /* { struct vnode *a_vp; int a_mode; struct ucred *a_cred; struct thread *a_td; struct file *a_fp; } */ *ap; { struct vnode *vp; struct file *fp; struct thread *td; struct fifoinfo *fip; struct pipe *fpipe; u_int gen; int error, stops_deferred; vp = ap->a_vp; fp = ap->a_fp; td = ap->a_td; ASSERT_VOP_ELOCKED(vp, "fifo_open"); if (fp == NULL || (ap->a_mode & FEXEC) != 0) return (EINVAL); if ((fip = vp->v_fifoinfo) == NULL) { error = pipe_named_ctor(&fpipe, td); if (error != 0) return (error); fip = malloc(sizeof(*fip), M_VNODE, M_WAITOK | M_ZERO); fip->fi_pipe = fpipe; fpipe->pipe_wgen = 0; KASSERT(vp->v_fifoinfo == NULL, ("fifo_open: v_fifoinfo race")); vp->v_fifoinfo = fip; } fpipe = fip->fi_pipe; KASSERT(fpipe != NULL, ("fifo_open: pipe is NULL")); /* * Use the pipe mutex here, in addition to the vnode lock, * in order to allow vnode lock dropping before msleep() calls * and still avoiding missed wakeups. */ PIPE_LOCK(fpipe); if (ap->a_mode & FREAD) { fip->fi_readers++; fip->fi_rgen++; if (fip->fi_readers == 1) { fpipe->pipe_state &= ~PIPE_EOF; if (fip->fi_writers > 0) { wakeup(&fip->fi_writers); pipeselwakeup(fpipe); } } fp->f_pipegen = fpipe->pipe_wgen - fip->fi_writers; } if (ap->a_mode & FWRITE) { if ((ap->a_mode & O_NONBLOCK) && fip->fi_readers == 0) { PIPE_UNLOCK(fpipe); if (fip->fi_writers == 0) fifo_cleanup(vp); return (ENXIO); } fip->fi_writers++; fip->fi_wgen++; if (fip->fi_writers == 1) { fpipe->pipe_state &= ~PIPE_EOF; if (fip->fi_readers > 0) { wakeup(&fip->fi_readers); pipeselwakeup(fpipe); } } } if ((ap->a_mode & O_NONBLOCK) == 0) { if ((ap->a_mode & FREAD) && fip->fi_writers == 0) { gen = fip->fi_wgen; VOP_UNLOCK(vp); stops_deferred = sigdeferstop(SIGDEFERSTOP_OFF); error = msleep(&fip->fi_readers, PIPE_MTX(fpipe), PDROP | PCATCH | PSOCK, "fifoor", 0); sigallowstop(stops_deferred); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (error != 0 && gen == fip->fi_wgen) { fip->fi_readers--; if (fip->fi_readers == 0) { PIPE_LOCK(fpipe); fpipe->pipe_state |= PIPE_EOF; if (fpipe->pipe_state & PIPE_WANTW) wakeup(fpipe); pipeselwakeup(fpipe); PIPE_UNLOCK(fpipe); fifo_cleanup(vp); } return (error); } PIPE_LOCK(fpipe); /* * We must have got woken up because we had a writer. * That (and not still having one) is the condition * that we must wait for. */ } if ((ap->a_mode & FWRITE) && fip->fi_readers == 0) { gen = fip->fi_rgen; VOP_UNLOCK(vp); stops_deferred = sigdeferstop(SIGDEFERSTOP_OFF); error = msleep(&fip->fi_writers, PIPE_MTX(fpipe), PDROP | PCATCH | PSOCK, "fifoow", 0); sigallowstop(stops_deferred); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (error != 0 && gen == fip->fi_rgen) { fip->fi_writers--; if (fip->fi_writers == 0) { PIPE_LOCK(fpipe); fpipe->pipe_state |= PIPE_EOF; if (fpipe->pipe_state & PIPE_WANTR) wakeup(fpipe); fpipe->pipe_wgen++; pipeselwakeup(fpipe); PIPE_UNLOCK(fpipe); fifo_cleanup(vp); } return (error); } /* * We must have got woken up because we had * a reader. That (and not still having one) * is the condition that we must wait for. */ PIPE_LOCK(fpipe); } } PIPE_UNLOCK(fpipe); KASSERT(fp != NULL, ("can't fifo/vnode bypass")); KASSERT(fp->f_ops == &badfileops, ("not badfileops in fifo_open")); finit(fp, fp->f_flag, DTYPE_FIFO, fpipe, &pipeops); return (0); } /* * Device close routine */ /* ARGSUSED */ static int fifo_close(ap) struct vop_close_args /* { struct vnode *a_vp; int a_fflag; struct ucred *a_cred; struct thread *a_td; } */ *ap; { struct vnode *vp; struct fifoinfo *fip; struct pipe *cpipe; vp = ap->a_vp; ASSERT_VOP_ELOCKED(vp, "fifo_close"); fip = vp->v_fifoinfo; /* * During open, it is possible that the fifo vnode is relocked * after the vnode is instantiated but before VOP_OPEN() is * done. For instance, vn_open_vnode() might need to upgrade * vnode lock, or ffs_vput_pair() needs to unlock vp to sync * dvp. In this case, reclaim can observe us with v_fifoinfo * equal to NULL. */ if (fip == NULL) return (0); cpipe = fip->fi_pipe; if (ap->a_fflag & FREAD) { fip->fi_readers--; if (fip->fi_readers == 0) { PIPE_LOCK(cpipe); cpipe->pipe_state |= PIPE_EOF; if ((cpipe->pipe_state & PIPE_WANTW)) { cpipe->pipe_state &= ~PIPE_WANTW; wakeup(cpipe); } pipeselwakeup(cpipe); PIPE_UNLOCK(cpipe); } } if (ap->a_fflag & FWRITE) { fip->fi_writers--; if (fip->fi_writers == 0) { PIPE_LOCK(cpipe); cpipe->pipe_state |= PIPE_EOF; if ((cpipe->pipe_state & PIPE_WANTR)) { cpipe->pipe_state &= ~PIPE_WANTR; wakeup(cpipe); } cpipe->pipe_wgen++; pipeselwakeup(cpipe); PIPE_UNLOCK(cpipe); } } fifo_cleanup(vp); return (0); } /* * Print out internal contents of a fifo vnode. */ int fifo_printinfo(vp) struct vnode *vp; { struct fifoinfo *fip = vp->v_fifoinfo; if (fip == NULL){ printf(", NULL v_fifoinfo"); return (0); } printf(", fifo with %ld readers and %ld writers", fip->fi_readers, fip->fi_writers); return (0); } /* * Print out the contents of a fifo vnode. */ static int fifo_print(ap) struct vop_print_args /* { struct vnode *a_vp; } */ *ap; { printf(" "); fifo_printinfo(ap->a_vp); printf("\n"); return (0); } /* * Fifo advisory byte-level locks. */ /* ARGSUSED */ static int fifo_advlock(ap) struct vop_advlock_args /* { struct vnode *a_vp; caddr_t a_id; int a_op; struct flock *a_fl; int a_flags; } */ *ap; { - return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); + if ((ap->a_flags & F_FLOCK) == 0) + return (EINVAL); + return (vop_stdadvlock(ap)); } diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c index ed7fe83cf02f..58c2d1939dba 100644 --- a/sys/kern/kern_descrip.c +++ b/sys/kern/kern_descrip.c @@ -1,5148 +1,5152 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #include "opt_ddb.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", "file desc to leader structures"); static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); MALLOC_DECLARE(M_FADVISE); static __read_mostly uma_zone_t file_zone; static __read_mostly uma_zone_t filedesc0_zone; __read_mostly uma_zone_t pwd_zone; VFS_SMR_DECLARE; static int closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, bool holdleaders, bool audit); static int fd_first_free(struct filedesc *fdp, int low, int size); static void fdgrowtable(struct filedesc *fdp, int nfd); static void fdgrowtable_exp(struct filedesc *fdp, int nfd); static void fdunused(struct filedesc *fdp, int fd); static void fdused(struct filedesc *fdp, int fd); static int getmaxfd(struct thread *td); static u_long *filecaps_copy_prep(const struct filecaps *src); static void filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, u_long *ioctls); static u_long *filecaps_free_prep(struct filecaps *fcaps); static void filecaps_free_finish(u_long *ioctls); static struct pwd *pwd_alloc(void); /* * Each process has: * * - An array of open file descriptors (fd_ofiles) * - An array of file flags (fd_ofileflags) * - A bitmap recording which descriptors are in use (fd_map) * * A process starts out with NDFILE descriptors. The value of NDFILE has * been selected based the historical limit of 20 open files, and an * assumption that the majority of processes, especially short-lived * processes like shells, will never need more. * * If this initial allocation is exhausted, a larger descriptor table and * map are allocated dynamically, and the pointers in the process's struct * filedesc are updated to point to those. This is repeated every time * the process runs out of file descriptors (provided it hasn't hit its * resource limit). * * Since threads may hold references to individual descriptor table * entries, the tables are never freed. Instead, they are placed on a * linked list and freed only when the struct filedesc is released. */ #define NDFILE 20 #define NDSLOTSIZE sizeof(NDSLOTTYPE) #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) #define NDSLOT(x) ((x) / NDENTRIES) #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) /* * SLIST entry used to keep track of ofiles which must be reclaimed when * the process exits. */ struct freetable { struct fdescenttbl *ft_table; SLIST_ENTRY(freetable) ft_next; }; /* * Initial allocation: a filedesc structure + the head of SLIST used to * keep track of old ofiles + enough space for NDFILE descriptors. */ struct fdescenttbl0 { int fdt_nfiles; struct filedescent fdt_ofiles[NDFILE]; }; struct filedesc0 { struct filedesc fd_fd; SLIST_HEAD(, freetable) fd_free; struct fdescenttbl0 fd_dfiles; NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; }; /* * Descriptor management. */ static int __exclusive_cache_line openfiles; /* actual number of open files */ struct mtx sigio_lock; /* mtx to protect pointers to sigio */ void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); /* * If low >= size, just return low. Otherwise find the first zero bit in the * given bitmap, starting at low and not exceeding size - 1. Return size if * not found. */ static int fd_first_free(struct filedesc *fdp, int low, int size) { NDSLOTTYPE *map = fdp->fd_map; NDSLOTTYPE mask; int off, maxoff; if (low >= size) return (low); off = NDSLOT(low); if (low % NDENTRIES) { mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); if ((mask &= ~map[off]) != 0UL) return (off * NDENTRIES + ffsl(mask) - 1); ++off; } for (maxoff = NDSLOTS(size); off < maxoff; ++off) if (map[off] != ~0UL) return (off * NDENTRIES + ffsl(~map[off]) - 1); return (size); } /* * Find the last used fd. * * Call this variant if fdp can't be modified by anyone else (e.g, during exec). * Otherwise use fdlastfile. */ int fdlastfile_single(struct filedesc *fdp) { NDSLOTTYPE *map = fdp->fd_map; int off, minoff; off = NDSLOT(fdp->fd_nfiles - 1); for (minoff = NDSLOT(0); off >= minoff; --off) if (map[off] != 0) return (off * NDENTRIES + flsl(map[off]) - 1); return (-1); } int fdlastfile(struct filedesc *fdp) { FILEDESC_LOCK_ASSERT(fdp); return (fdlastfile_single(fdp)); } static int fdisused(struct filedesc *fdp, int fd) { KASSERT(fd >= 0 && fd < fdp->fd_nfiles, ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); } /* * Mark a file descriptor as used. */ static void fdused_init(struct filedesc *fdp, int fd) { KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); } static void fdused(struct filedesc *fdp, int fd) { FILEDESC_XLOCK_ASSERT(fdp); fdused_init(fdp, fd); if (fd == fdp->fd_freefile) fdp->fd_freefile++; } /* * Mark a file descriptor as unused. */ static void fdunused(struct filedesc *fdp, int fd) { FILEDESC_XLOCK_ASSERT(fdp); KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, ("fd=%d is still in use", fd)); fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); if (fd < fdp->fd_freefile) fdp->fd_freefile = fd; } /* * Free a file descriptor. * * Avoid some work if fdp is about to be destroyed. */ static inline void fdefree_last(struct filedescent *fde) { filecaps_free(&fde->fde_caps); } static inline void fdfree(struct filedesc *fdp, int fd) { struct filedescent *fde; FILEDESC_XLOCK_ASSERT(fdp); fde = &fdp->fd_ofiles[fd]; #ifdef CAPABILITIES seqc_write_begin(&fde->fde_seqc); #endif fde->fde_file = NULL; #ifdef CAPABILITIES seqc_write_end(&fde->fde_seqc); #endif fdefree_last(fde); fdunused(fdp, fd); } /* * System calls on descriptors. */ #ifndef _SYS_SYSPROTO_H_ struct getdtablesize_args { int dummy; }; #endif /* ARGSUSED */ int sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) { #ifdef RACCT uint64_t lim; #endif td->td_retval[0] = getmaxfd(td); #ifdef RACCT PROC_LOCK(td->td_proc); lim = racct_get_limit(td->td_proc, RACCT_NOFILE); PROC_UNLOCK(td->td_proc); if (lim < td->td_retval[0]) td->td_retval[0] = lim; #endif return (0); } /* * Duplicate a file descriptor to a particular value. * * Note: keep in mind that a potential race condition exists when closing * descriptors from a shared descriptor table (via rfork). */ #ifndef _SYS_SYSPROTO_H_ struct dup2_args { u_int from; u_int to; }; #endif /* ARGSUSED */ int sys_dup2(struct thread *td, struct dup2_args *uap) { return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); } /* * Duplicate a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct dup_args { u_int fd; }; #endif /* ARGSUSED */ int sys_dup(struct thread *td, struct dup_args *uap) { return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); } /* * The file control system call. */ #ifndef _SYS_SYSPROTO_H_ struct fcntl_args { int fd; int cmd; long arg; }; #endif /* ARGSUSED */ int sys_fcntl(struct thread *td, struct fcntl_args *uap) { return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); } int kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) { struct flock fl; struct __oflock ofl; intptr_t arg1; int error, newcmd; error = 0; newcmd = cmd; switch (cmd) { case F_OGETLK: case F_OSETLK: case F_OSETLKW: /* * Convert old flock structure to new. */ error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); fl.l_start = ofl.l_start; fl.l_len = ofl.l_len; fl.l_pid = ofl.l_pid; fl.l_type = ofl.l_type; fl.l_whence = ofl.l_whence; fl.l_sysid = 0; switch (cmd) { case F_OGETLK: newcmd = F_GETLK; break; case F_OSETLK: newcmd = F_SETLK; break; case F_OSETLKW: newcmd = F_SETLKW; break; } arg1 = (intptr_t)&fl; break; case F_GETLK: case F_SETLK: case F_SETLKW: case F_SETLK_REMOTE: error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); arg1 = (intptr_t)&fl; break; default: arg1 = arg; break; } if (error) return (error); error = kern_fcntl(td, fd, newcmd, arg1); if (error) return (error); if (cmd == F_OGETLK) { ofl.l_start = fl.l_start; ofl.l_len = fl.l_len; ofl.l_pid = fl.l_pid; ofl.l_type = fl.l_type; ofl.l_whence = fl.l_whence; error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); } else if (cmd == F_GETLK) { error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); } return (error); } int kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) { struct filedesc *fdp; struct flock *flp; struct file *fp, *fp2; struct filedescent *fde; struct proc *p; struct vnode *vp; struct mount *mp; int error, flg, seals, tmp; uint64_t bsize; off_t foffset; error = 0; flg = F_POSIX; p = td->td_proc; fdp = p->p_fd; AUDIT_ARG_FD(cmd); AUDIT_ARG_CMD(cmd); switch (cmd) { case F_DUPFD: tmp = arg; error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); break; case F_DUPFD_CLOEXEC: tmp = arg; error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); break; case F_DUP2FD: tmp = arg; error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); break; case F_DUP2FD_CLOEXEC: tmp = arg; error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); break; case F_GETFD: error = EBADF; FILEDESC_SLOCK(fdp); fde = fdeget_locked(fdp, fd); if (fde != NULL) { td->td_retval[0] = (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; error = 0; } FILEDESC_SUNLOCK(fdp); break; case F_SETFD: error = EBADF; FILEDESC_XLOCK(fdp); fde = fdeget_locked(fdp, fd); if (fde != NULL) { fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); error = 0; } FILEDESC_XUNLOCK(fdp); break; case F_GETFL: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); if (error != 0) break; td->td_retval[0] = OFLAGS(fp->f_flag); fdrop(fp, td); break; case F_SETFL: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); if (error != 0) break; if (fp->f_ops == &path_fileops) { fdrop(fp, td); error = EBADF; break; } do { tmp = flg = fp->f_flag; tmp &= ~FCNTLFLAGS; tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); tmp = fp->f_flag & FNONBLOCK; error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); if (error != 0) { fdrop(fp, td); break; } tmp = fp->f_flag & FASYNC; error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); if (error == 0) { fdrop(fp, td); break; } atomic_clear_int(&fp->f_flag, FNONBLOCK); tmp = 0; (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); fdrop(fp, td); break; case F_GETOWN: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); if (error != 0) break; error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); if (error == 0) td->td_retval[0] = tmp; fdrop(fp, td); break; case F_SETOWN: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); if (error != 0) break; tmp = arg; error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); fdrop(fp, td); break; case F_SETLK_REMOTE: error = priv_check(td, PRIV_NFS_LOCKD); if (error != 0) return (error); flg = F_REMOTE; goto do_setlk; case F_SETLKW: flg |= F_WAIT; /* FALLTHROUGH F_SETLK */ case F_SETLK: do_setlk: flp = (struct flock *)arg; if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { error = EINVAL; break; } error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); if (error != 0) break; if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { error = EBADF; fdrop(fp, td); break; } if (flp->l_whence == SEEK_CUR) { foffset = foffset_get(fp); if (foffset < 0 || (flp->l_start > 0 && foffset > OFF_MAX - flp->l_start)) { error = EOVERFLOW; fdrop(fp, td); break; } flp->l_start += foffset; } vp = fp->f_vnode; switch (flp->l_type) { case F_RDLCK: if ((fp->f_flag & FREAD) == 0) { error = EBADF; break; } if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { PROC_LOCK(p->p_leader); p->p_leader->p_flag |= P_ADVLOCK; PROC_UNLOCK(p->p_leader); } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, flp, flg); break; case F_WRLCK: if ((fp->f_flag & FWRITE) == 0) { error = EBADF; break; } if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { PROC_LOCK(p->p_leader); p->p_leader->p_flag |= P_ADVLOCK; PROC_UNLOCK(p->p_leader); } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, flp, flg); break; case F_UNLCK: error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, flp, flg); break; case F_UNLCKSYS: if (flg != F_REMOTE) { error = EINVAL; break; } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCKSYS, flp, flg); break; default: error = EINVAL; break; } if (error != 0 || flp->l_type == F_UNLCK || flp->l_type == F_UNLCKSYS) { fdrop(fp, td); break; } /* * Check for a race with close. * * The vnode is now advisory locked (or unlocked, but this case * is not really important) as the caller requested. * We had to drop the filedesc lock, so we need to recheck if * the descriptor is still valid, because if it was closed * in the meantime we need to remove advisory lock from the * vnode - close on any descriptor leading to an advisory * locked vnode, removes that lock. * We will return 0 on purpose in that case, as the result of * successful advisory lock might have been externally visible * already. This is fine - effectively we pretend to the caller * that the closing thread was a bit slower and that the * advisory lock succeeded before the close. */ error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); if (error != 0) { fdrop(fp, td); break; } if (fp != fp2) { flp->l_whence = SEEK_SET; flp->l_start = 0; flp->l_len = 0; flp->l_type = F_UNLCK; (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, flp, F_POSIX); } fdrop(fp, td); fdrop(fp2, td); break; case F_GETLK: error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); if (error != 0) break; if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { error = EBADF; fdrop(fp, td); break; } flp = (struct flock *)arg; if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && flp->l_type != F_UNLCK) { error = EINVAL; fdrop(fp, td); break; } if (flp->l_whence == SEEK_CUR) { foffset = foffset_get(fp); if ((flp->l_start > 0 && foffset > OFF_MAX - flp->l_start) || (flp->l_start < 0 && foffset < OFF_MIN - flp->l_start)) { error = EOVERFLOW; fdrop(fp, td); break; } flp->l_start += foffset; } vp = fp->f_vnode; error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, F_POSIX); fdrop(fp, td); break; case F_ADD_SEALS: error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); if (error != 0) break; error = fo_add_seals(fp, arg); fdrop(fp, td); break; case F_GET_SEALS: error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); if (error != 0) break; if (fo_get_seals(fp, &seals) == 0) td->td_retval[0] = seals; else error = EINVAL; fdrop(fp, td); break; case F_RDAHEAD: arg = arg ? 128 * 1024: 0; /* FALLTHROUGH */ case F_READAHEAD: error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); if (error != 0) break; if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { fdrop(fp, td); error = EBADF; break; } vp = fp->f_vnode; if (vp->v_type != VREG) { fdrop(fp, td); error = ENOTTY; break; } /* * Exclusive lock synchronizes against f_seqcount reads and * writes in sequential_heuristic(). */ error = vn_lock(vp, LK_EXCLUSIVE); if (error != 0) { fdrop(fp, td); break; } if (arg >= 0) { bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; arg = MIN(arg, INT_MAX - bsize + 1); fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, (arg + bsize - 1) / bsize); atomic_set_int(&fp->f_flag, FRDAHEAD); } else { atomic_clear_int(&fp->f_flag, FRDAHEAD); } VOP_UNLOCK(vp); fdrop(fp, td); break; case F_ISUNIONSTACK: /* * Check if the vnode is part of a union stack (either the * "union" flag from mount(2) or unionfs). * * Prior to introduction of this op libc's readdir would call * fstatfs(2), in effect unnecessarily copying kilobytes of * data just to check fs name and a mount flag. * * Fixing the code to handle everything in the kernel instead * is a non-trivial endeavor and has low priority, thus this * horrible kludge facilitates the current behavior in a much * cheaper manner until someone(tm) sorts this out. */ error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); if (error != 0) break; if (fp->f_type != DTYPE_VNODE) { fdrop(fp, td); error = EBADF; break; } vp = fp->f_vnode; /* * Since we don't prevent dooming the vnode even non-null mp * found can become immediately stale. This is tolerable since * mount points are type-stable (providing safe memory access) * and any vfs op on this vnode going forward will return an * error (meaning return value in this case is meaningless). */ mp = atomic_load_ptr(&vp->v_mount); if (__predict_false(mp == NULL)) { fdrop(fp, td); error = EBADF; break; } td->td_retval[0] = 0; if (mp->mnt_kern_flag & MNTK_UNIONFS || mp->mnt_flag & MNT_UNION) td->td_retval[0] = 1; fdrop(fp, td); break; default: error = EINVAL; break; } return (error); } static int getmaxfd(struct thread *td) { return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); } /* * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). */ int kern_dup(struct thread *td, u_int mode, int flags, int old, int new) { struct filedesc *fdp; struct filedescent *oldfde, *newfde; struct proc *p; struct file *delfp, *oldfp; u_long *oioctls, *nioctls; int error, maxfd; p = td->td_proc; fdp = p->p_fd; oioctls = NULL; MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); MPASS(mode < FDDUP_LASTMODE); AUDIT_ARG_FD(old); /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ /* * Verify we have a valid descriptor to dup from and possibly to * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should * return EINVAL when the new descriptor is out of bounds. */ if (old < 0) return (EBADF); if (new < 0) return (mode == FDDUP_FCNTL ? EINVAL : EBADF); maxfd = getmaxfd(td); if (new >= maxfd) return (mode == FDDUP_FCNTL ? EINVAL : EBADF); error = EBADF; FILEDESC_XLOCK(fdp); if (fget_locked(fdp, old) == NULL) goto unlock; if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { td->td_retval[0] = new; if (flags & FDDUP_FLAG_CLOEXEC) fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; error = 0; goto unlock; } oldfde = &fdp->fd_ofiles[old]; oldfp = oldfde->fde_file; if (!fhold(oldfp)) goto unlock; /* * If the caller specified a file descriptor, make sure the file * table is large enough to hold it, and grab it. Otherwise, just * allocate a new descriptor the usual way. */ switch (mode) { case FDDUP_NORMAL: case FDDUP_FCNTL: if ((error = fdalloc(td, new, &new)) != 0) { fdrop(oldfp, td); goto unlock; } break; case FDDUP_MUSTREPLACE: /* Target file descriptor must exist. */ if (fget_locked(fdp, new) == NULL) { fdrop(oldfp, td); goto unlock; } break; case FDDUP_FIXED: if (new >= fdp->fd_nfiles) { /* * The resource limits are here instead of e.g. * fdalloc(), because the file descriptor table may be * shared between processes, so we can't really use * racct_add()/racct_sub(). Instead of counting the * number of actually allocated descriptors, just put * the limit on the size of the file descriptor table. */ #ifdef RACCT if (RACCT_ENABLED()) { error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); if (error != 0) { error = EMFILE; fdrop(oldfp, td); goto unlock; } } #endif fdgrowtable_exp(fdp, new + 1); } if (!fdisused(fdp, new)) fdused(fdp, new); break; default: KASSERT(0, ("%s unsupported mode %d", __func__, mode)); } KASSERT(old != new, ("new fd is same as old")); /* Refetch oldfde because the table may have grown and old one freed. */ oldfde = &fdp->fd_ofiles[old]; KASSERT(oldfp == oldfde->fde_file, ("fdt_ofiles shift from growth observed at fd %d", old)); newfde = &fdp->fd_ofiles[new]; delfp = newfde->fde_file; nioctls = filecaps_copy_prep(&oldfde->fde_caps); /* * Duplicate the source descriptor. */ #ifdef CAPABILITIES seqc_write_begin(&newfde->fde_seqc); #endif oioctls = filecaps_free_prep(&newfde->fde_caps); memcpy(newfde, oldfde, fde_change_size); filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, nioctls); if ((flags & FDDUP_FLAG_CLOEXEC) != 0) newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; else newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; #ifdef CAPABILITIES seqc_write_end(&newfde->fde_seqc); #endif td->td_retval[0] = new; error = 0; if (delfp != NULL) { (void) closefp(fdp, new, delfp, td, true, false); FILEDESC_UNLOCK_ASSERT(fdp); } else { unlock: FILEDESC_XUNLOCK(fdp); } filecaps_free_finish(oioctls); return (error); } static void sigiofree(struct sigio *sigio) { crfree(sigio->sio_ucred); free(sigio, M_SIGIO); } static struct sigio * funsetown_locked(struct sigio *sigio) { struct proc *p; struct pgrp *pg; SIGIO_ASSERT_LOCKED(); if (sigio == NULL) return (NULL); *sigio->sio_myref = NULL; if (sigio->sio_pgid < 0) { pg = sigio->sio_pgrp; PGRP_LOCK(pg); SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); PGRP_UNLOCK(pg); } else { p = sigio->sio_proc; PROC_LOCK(p); SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); PROC_UNLOCK(p); } return (sigio); } /* * If sigio is on the list associated with a process or process group, * disable signalling from the device, remove sigio from the list and * free sigio. */ void funsetown(struct sigio **sigiop) { struct sigio *sigio; /* Racy check, consumers must provide synchronization. */ if (*sigiop == NULL) return; SIGIO_LOCK(); sigio = funsetown_locked(*sigiop); SIGIO_UNLOCK(); if (sigio != NULL) sigiofree(sigio); } /* * Free a list of sigio structures. The caller must ensure that new sigio * structures cannot be added after this point. For process groups this is * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves * as an interlock. */ void funsetownlst(struct sigiolst *sigiolst) { struct proc *p; struct pgrp *pg; struct sigio *sigio, *tmp; /* Racy check. */ sigio = SLIST_FIRST(sigiolst); if (sigio == NULL) return; p = NULL; pg = NULL; SIGIO_LOCK(); sigio = SLIST_FIRST(sigiolst); if (sigio == NULL) { SIGIO_UNLOCK(); return; } /* * Every entry of the list should belong to a single proc or pgrp. */ if (sigio->sio_pgid < 0) { pg = sigio->sio_pgrp; sx_assert(&proctree_lock, SX_XLOCKED); PGRP_LOCK(pg); } else /* if (sigio->sio_pgid > 0) */ { p = sigio->sio_proc; PROC_LOCK(p); KASSERT((p->p_flag & P_WEXIT) != 0, ("%s: process %p is not exiting", __func__, p)); } SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { *sigio->sio_myref = NULL; if (pg != NULL) { KASSERT(sigio->sio_pgid < 0, ("Proc sigio in pgrp sigio list")); KASSERT(sigio->sio_pgrp == pg, ("Bogus pgrp in sigio list")); } else /* if (p != NULL) */ { KASSERT(sigio->sio_pgid > 0, ("Pgrp sigio in proc sigio list")); KASSERT(sigio->sio_proc == p, ("Bogus proc in sigio list")); } } if (pg != NULL) PGRP_UNLOCK(pg); else PROC_UNLOCK(p); SIGIO_UNLOCK(); SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) sigiofree(sigio); } /* * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). * * After permission checking, add a sigio structure to the sigio list for * the process or process group. */ int fsetown(pid_t pgid, struct sigio **sigiop) { struct proc *proc; struct pgrp *pgrp; struct sigio *osigio, *sigio; int ret; if (pgid == 0) { funsetown(sigiop); return (0); } sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); sigio->sio_pgid = pgid; sigio->sio_ucred = crhold(curthread->td_ucred); sigio->sio_myref = sigiop; ret = 0; if (pgid > 0) { ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); SIGIO_LOCK(); osigio = funsetown_locked(*sigiop); if (ret == 0) { PROC_LOCK(proc); _PRELE(proc); if ((proc->p_flag & P_WEXIT) != 0) { ret = ESRCH; } else if (proc->p_session != curthread->td_proc->p_session) { /* * Policy - Don't allow a process to FSETOWN a * process in another session. * * Remove this test to allow maximum flexibility * or restrict FSETOWN to the current process or * process group for maximum safety. */ ret = EPERM; } else { sigio->sio_proc = proc; SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); } PROC_UNLOCK(proc); } } else /* if (pgid < 0) */ { sx_slock(&proctree_lock); SIGIO_LOCK(); osigio = funsetown_locked(*sigiop); pgrp = pgfind(-pgid); if (pgrp == NULL) { ret = ESRCH; } else { if (pgrp->pg_session != curthread->td_proc->p_session) { /* * Policy - Don't allow a process to FSETOWN a * process in another session. * * Remove this test to allow maximum flexibility * or restrict FSETOWN to the current process or * process group for maximum safety. */ ret = EPERM; } else { sigio->sio_pgrp = pgrp; SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); } PGRP_UNLOCK(pgrp); } sx_sunlock(&proctree_lock); } if (ret == 0) *sigiop = sigio; SIGIO_UNLOCK(); if (osigio != NULL) sigiofree(osigio); return (ret); } /* * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). */ pid_t fgetown(struct sigio **sigiop) { pid_t pgid; SIGIO_LOCK(); pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; SIGIO_UNLOCK(); return (pgid); } static int closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, bool audit) { int error; FILEDESC_XLOCK_ASSERT(fdp); /* * We now hold the fp reference that used to be owned by the * descriptor array. We have to unlock the FILEDESC *AFTER* * knote_fdclose to prevent a race of the fd getting opened, a knote * added, and deleteing a knote for the new fd. */ if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) knote_fdclose(td, fd); /* * We need to notify mqueue if the object is of type mqueue. */ if (__predict_false(fp->f_type == DTYPE_MQUEUE)) mq_fdclose(td, fd, fp); FILEDESC_XUNLOCK(fdp); #ifdef AUDIT if (AUDITING_TD(td) && audit) audit_sysclose(td, fd, fp); #endif error = closef(fp, td); /* * All paths leading up to closefp() will have already removed or * replaced the fd in the filedesc table, so a restart would not * operate on the same file. */ if (error == ERESTART) error = EINTR; return (error); } static int closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, bool holdleaders, bool audit) { int error; FILEDESC_XLOCK_ASSERT(fdp); if (holdleaders) { if (td->td_proc->p_fdtol != NULL) { /* * Ask fdfree() to sleep to ensure that all relevant * process leaders can be traversed in closef(). */ fdp->fd_holdleaderscount++; } else { holdleaders = false; } } error = closefp_impl(fdp, fd, fp, td, audit); if (holdleaders) { FILEDESC_XLOCK(fdp); fdp->fd_holdleaderscount--; if (fdp->fd_holdleaderscount == 0 && fdp->fd_holdleaderswakeup != 0) { fdp->fd_holdleaderswakeup = 0; wakeup(&fdp->fd_holdleaderscount); } FILEDESC_XUNLOCK(fdp); } return (error); } static int closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, bool holdleaders, bool audit) { FILEDESC_XLOCK_ASSERT(fdp); if (__predict_false(td->td_proc->p_fdtol != NULL)) { return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); } else { return (closefp_impl(fdp, fd, fp, td, audit)); } } /* * Close a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct close_args { int fd; }; #endif /* ARGSUSED */ int sys_close(struct thread *td, struct close_args *uap) { return (kern_close(td, uap->fd)); } int kern_close(struct thread *td, int fd) { struct filedesc *fdp; struct file *fp; fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); if ((fp = fget_locked(fdp, fd)) == NULL) { FILEDESC_XUNLOCK(fdp); return (EBADF); } fdfree(fdp, fd); /* closefp() drops the FILEDESC lock for us. */ return (closefp(fdp, fd, fp, td, true, true)); } int kern_close_range(struct thread *td, u_int lowfd, u_int highfd) { struct filedesc *fdp; const struct fdescenttbl *fdt; struct file *fp; int fd; /* * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 * open should not be a usage error. From a close_range() perspective, * close_range(3, ~0U, 0) in the same scenario should also likely not * be a usage error as all fd above 3 are in-fact already closed. */ if (highfd < lowfd) { return (EINVAL); } fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); fdt = atomic_load_ptr(&fdp->fd_files); highfd = MIN(highfd, fdt->fdt_nfiles - 1); fd = lowfd; if (__predict_false(fd > highfd)) { goto out_locked; } for (;;) { fp = fdt->fdt_ofiles[fd].fde_file; if (fp == NULL) { if (fd == highfd) goto out_locked; } else { fdfree(fdp, fd); (void) closefp(fdp, fd, fp, td, true, true); if (fd == highfd) goto out_unlocked; FILEDESC_XLOCK(fdp); fdt = atomic_load_ptr(&fdp->fd_files); } fd++; } out_locked: FILEDESC_XUNLOCK(fdp); out_unlocked: return (0); } #ifndef _SYS_SYSPROTO_H_ struct close_range_args { u_int lowfd; u_int highfd; int flags; }; #endif int sys_close_range(struct thread *td, struct close_range_args *uap) { AUDIT_ARG_FD(uap->lowfd); AUDIT_ARG_CMD(uap->highfd); AUDIT_ARG_FFLAGS(uap->flags); /* No flags currently defined */ if (uap->flags != 0) return (EINVAL); return (kern_close_range(td, uap->lowfd, uap->highfd)); } #ifdef COMPAT_FREEBSD12 /* * Close open file descriptors. */ #ifndef _SYS_SYSPROTO_H_ struct freebsd12_closefrom_args { int lowfd; }; #endif /* ARGSUSED */ int freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) { u_int lowfd; AUDIT_ARG_FD(uap->lowfd); /* * Treat negative starting file descriptor values identical to * closefrom(0) which closes all files. */ lowfd = MAX(0, uap->lowfd); return (kern_close_range(td, lowfd, ~0U)); } #endif /* COMPAT_FREEBSD12 */ #if defined(COMPAT_43) /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct ofstat_args { int fd; struct ostat *sb; }; #endif /* ARGSUSED */ int ofstat(struct thread *td, struct ofstat_args *uap) { struct ostat oub; struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error == 0) { cvtstat(&ub, &oub); error = copyout(&oub, uap->sb, sizeof(oub)); } return (error); } #endif /* COMPAT_43 */ #if defined(COMPAT_FREEBSD11) int freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) { struct stat sb; struct freebsd11_stat osb; int error; error = kern_fstat(td, uap->fd, &sb); if (error != 0) return (error); error = freebsd11_cvtstat(&sb, &osb); if (error == 0) error = copyout(&osb, uap->sb, sizeof(osb)); return (error); } #endif /* COMPAT_FREEBSD11 */ /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct fstat_args { int fd; struct stat *sb; }; #endif /* ARGSUSED */ int sys_fstat(struct thread *td, struct fstat_args *uap) { struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error == 0) error = copyout(&ub, uap->sb, sizeof(ub)); return (error); } int kern_fstat(struct thread *td, int fd, struct stat *sbp) { struct file *fp; int error; AUDIT_ARG_FD(fd); error = fget(td, fd, &cap_fstat_rights, &fp); if (__predict_false(error != 0)) return (error); AUDIT_ARG_FILE(td->td_proc, fp); error = fo_stat(fp, sbp, td->td_ucred, td); fdrop(fp, td); #ifdef __STAT_TIME_T_EXT sbp->st_atim_ext = 0; sbp->st_mtim_ext = 0; sbp->st_ctim_ext = 0; sbp->st_btim_ext = 0; #endif #ifdef KTRACE if (KTRPOINT(td, KTR_STRUCT)) ktrstat_error(sbp, error); #endif return (error); } #if defined(COMPAT_FREEBSD11) /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct freebsd11_nfstat_args { int fd; struct nstat *sb; }; #endif /* ARGSUSED */ int freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) { struct nstat nub; struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error == 0) { freebsd11_cvtnstat(&ub, &nub); error = copyout(&nub, uap->sb, sizeof(nub)); } return (error); } #endif /* COMPAT_FREEBSD11 */ /* * Return pathconf information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct fpathconf_args { int fd; int name; }; #endif /* ARGSUSED */ int sys_fpathconf(struct thread *td, struct fpathconf_args *uap) { long value; int error; error = kern_fpathconf(td, uap->fd, uap->name, &value); if (error == 0) td->td_retval[0] = value; return (error); } int kern_fpathconf(struct thread *td, int fd, int name, long *valuep) { struct file *fp; struct vnode *vp; int error; error = fget(td, fd, &cap_fpathconf_rights, &fp); if (error != 0) return (error); if (name == _PC_ASYNC_IO) { *valuep = _POSIX_ASYNCHRONOUS_IO; goto out; } vp = fp->f_vnode; if (vp != NULL) { vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_PATHCONF(vp, name, valuep); VOP_UNLOCK(vp); } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { if (name != _PC_PIPE_BUF) { error = EINVAL; } else { *valuep = PIPE_BUF; error = 0; } } else { error = EOPNOTSUPP; } out: fdrop(fp, td); return (error); } /* * Copy filecaps structure allocating memory for ioctls array if needed. * * The last parameter indicates whether the fdtable is locked. If it is not and * ioctls are encountered, copying fails and the caller must lock the table. * * Note that if the table was not locked, the caller has to check the relevant * sequence counter to determine whether the operation was successful. */ bool filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) { size_t size; if (src->fc_ioctls != NULL && !locked) return (false); memcpy(dst, src, sizeof(*src)); if (src->fc_ioctls == NULL) return (true); KASSERT(src->fc_nioctls > 0, ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); memcpy(dst->fc_ioctls, src->fc_ioctls, size); return (true); } static u_long * filecaps_copy_prep(const struct filecaps *src) { u_long *ioctls; size_t size; if (__predict_true(src->fc_ioctls == NULL)) return (NULL); KASSERT(src->fc_nioctls > 0, ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; ioctls = malloc(size, M_FILECAPS, M_WAITOK); return (ioctls); } static void filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, u_long *ioctls) { size_t size; *dst = *src; if (__predict_true(src->fc_ioctls == NULL)) { MPASS(ioctls == NULL); return; } size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; dst->fc_ioctls = ioctls; bcopy(src->fc_ioctls, dst->fc_ioctls, size); } /* * Move filecaps structure to the new place and clear the old place. */ void filecaps_move(struct filecaps *src, struct filecaps *dst) { *dst = *src; bzero(src, sizeof(*src)); } /* * Fill the given filecaps structure with full rights. */ static void filecaps_fill(struct filecaps *fcaps) { CAP_ALL(&fcaps->fc_rights); fcaps->fc_ioctls = NULL; fcaps->fc_nioctls = -1; fcaps->fc_fcntls = CAP_FCNTL_ALL; } /* * Free memory allocated within filecaps structure. */ void filecaps_free(struct filecaps *fcaps) { free(fcaps->fc_ioctls, M_FILECAPS); bzero(fcaps, sizeof(*fcaps)); } static u_long * filecaps_free_prep(struct filecaps *fcaps) { u_long *ioctls; ioctls = fcaps->fc_ioctls; bzero(fcaps, sizeof(*fcaps)); return (ioctls); } static void filecaps_free_finish(u_long *ioctls) { free(ioctls, M_FILECAPS); } /* * Validate the given filecaps structure. */ static void filecaps_validate(const struct filecaps *fcaps, const char *func) { KASSERT(cap_rights_is_valid(&fcaps->fc_rights), ("%s: invalid rights", func)); KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, ("%s: invalid fcntls", func)); KASSERT(fcaps->fc_fcntls == 0 || cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), ("%s: fcntls without CAP_FCNTL", func)); KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), ("%s: invalid ioctls", func)); KASSERT(fcaps->fc_nioctls == 0 || cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), ("%s: ioctls without CAP_IOCTL", func)); } static void fdgrowtable_exp(struct filedesc *fdp, int nfd) { int nfd1; FILEDESC_XLOCK_ASSERT(fdp); nfd1 = fdp->fd_nfiles * 2; if (nfd1 < nfd) nfd1 = nfd; fdgrowtable(fdp, nfd1); } /* * Grow the file table to accommodate (at least) nfd descriptors. */ static void fdgrowtable(struct filedesc *fdp, int nfd) { struct filedesc0 *fdp0; struct freetable *ft; struct fdescenttbl *ntable; struct fdescenttbl *otable; int nnfiles, onfiles; NDSLOTTYPE *nmap, *omap; KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); /* save old values */ onfiles = fdp->fd_nfiles; otable = fdp->fd_files; omap = fdp->fd_map; /* compute the size of the new table */ nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ if (nnfiles <= onfiles) /* the table is already large enough */ return; /* * Allocate a new table. We need enough space for the number of * entries, file entries themselves and the struct freetable we will use * when we decommission the table and place it on the freelist. * We place the struct freetable in the middle so we don't have * to worry about padding. */ ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + nnfiles * sizeof(ntable->fdt_ofiles[0]) + sizeof(struct freetable), M_FILEDESC, M_ZERO | M_WAITOK); /* copy the old data */ ntable->fdt_nfiles = nnfiles; memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, onfiles * sizeof(ntable->fdt_ofiles[0])); /* * Allocate a new map only if the old is not large enough. It will * grow at a slower rate than the table as it can map more * entries than the table can hold. */ if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, M_ZERO | M_WAITOK); /* copy over the old data and update the pointer */ memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); fdp->fd_map = nmap; } /* * Make sure that ntable is correctly initialized before we replace * fd_files poiner. Otherwise fget_unlocked() may see inconsistent * data. */ atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); /* * Free the old file table when not shared by other threads or processes. * The old file table is considered to be shared when either are true: * - The process has more than one thread. * - The file descriptor table has been shared via fdshare(). * * When shared, the old file table will be placed on a freelist * which will be processed when the struct filedesc is released. * * Note that if onfiles == NDFILE, we're dealing with the original * static allocation contained within (struct filedesc0 *)fdp, * which must not be freed. */ if (onfiles > NDFILE) { /* * Note we may be called here from fdinit while allocating a * table for a new process in which case ->p_fd points * elsewhere. */ if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { free(otable, M_FILEDESC); } else { ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; fdp0 = (struct filedesc0 *)fdp; ft->ft_table = otable; SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); } } /* * The map does not have the same possibility of threads still * holding references to it. So always free it as long as it * does not reference the original static allocation. */ if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) free(omap, M_FILEDESC); } /* * Allocate a file descriptor for the process. */ int fdalloc(struct thread *td, int minfd, int *result) { struct proc *p = td->td_proc; struct filedesc *fdp = p->p_fd; int fd, maxfd, allocfd; #ifdef RACCT int error; #endif FILEDESC_XLOCK_ASSERT(fdp); if (fdp->fd_freefile > minfd) minfd = fdp->fd_freefile; maxfd = getmaxfd(td); /* * Search the bitmap for a free descriptor starting at minfd. * If none is found, grow the file table. */ fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); if (__predict_false(fd >= maxfd)) return (EMFILE); if (__predict_false(fd >= fdp->fd_nfiles)) { allocfd = min(fd * 2, maxfd); #ifdef RACCT if (RACCT_ENABLED()) { error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); if (error != 0) return (EMFILE); } #endif /* * fd is already equal to first free descriptor >= minfd, so * we only need to grow the table and we are done. */ fdgrowtable_exp(fdp, allocfd); } /* * Perform some sanity checks, then mark the file descriptor as * used and return it to the caller. */ KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), ("invalid descriptor %d", fd)); KASSERT(!fdisused(fdp, fd), ("fd_first_free() returned non-free descriptor")); KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, ("file descriptor isn't free")); fdused(fdp, fd); *result = fd; return (0); } /* * Allocate n file descriptors for the process. */ int fdallocn(struct thread *td, int minfd, int *fds, int n) { struct proc *p = td->td_proc; struct filedesc *fdp = p->p_fd; int i; FILEDESC_XLOCK_ASSERT(fdp); for (i = 0; i < n; i++) if (fdalloc(td, 0, &fds[i]) != 0) break; if (i < n) { for (i--; i >= 0; i--) fdunused(fdp, fds[i]); return (EMFILE); } return (0); } /* * Create a new open file structure and allocate a file descriptor for the * process that refers to it. We add one reference to the file for the * descriptor table and one reference for resultfp. This is to prevent us * being preempted and the entry in the descriptor table closed after we * release the FILEDESC lock. */ int falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, struct filecaps *fcaps) { struct file *fp; int error, fd; MPASS(resultfp != NULL); MPASS(resultfd != NULL); error = _falloc_noinstall(td, &fp, 2); if (__predict_false(error != 0)) { return (error); } error = finstall_refed(td, fp, &fd, flags, fcaps); if (__predict_false(error != 0)) { falloc_abort(td, fp); return (error); } *resultfp = fp; *resultfd = fd; return (0); } /* * Create a new open file structure without allocating a file descriptor. */ int _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) { struct file *fp; int maxuserfiles = maxfiles - (maxfiles / 20); int openfiles_new; static struct timeval lastfail; static int curfail; KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); MPASS(n > 0); openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; if ((openfiles_new >= maxuserfiles && priv_check(td, PRIV_MAXFILES) != 0) || openfiles_new >= maxfiles) { atomic_subtract_int(&openfiles, 1); if (ppsratecheck(&lastfail, &curfail, 1)) { printf("kern.maxfiles limit exceeded by uid %i, (%s) " "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); } return (ENFILE); } fp = uma_zalloc(file_zone, M_WAITOK); bzero(fp, sizeof(*fp)); refcount_init(&fp->f_count, n); fp->f_cred = crhold(td->td_ucred); fp->f_ops = &badfileops; *resultfp = fp; return (0); } void falloc_abort(struct thread *td, struct file *fp) { /* * For assertion purposes. */ refcount_init(&fp->f_count, 0); _fdrop(fp, td); } /* * Install a file in a file descriptor table. */ void _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, struct filecaps *fcaps) { struct filedescent *fde; MPASS(fp != NULL); if (fcaps != NULL) filecaps_validate(fcaps, __func__); FILEDESC_XLOCK_ASSERT(fdp); fde = &fdp->fd_ofiles[fd]; #ifdef CAPABILITIES seqc_write_begin(&fde->fde_seqc); #endif fde->fde_file = fp; fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; if (fcaps != NULL) filecaps_move(fcaps, &fde->fde_caps); else filecaps_fill(&fde->fde_caps); #ifdef CAPABILITIES seqc_write_end(&fde->fde_seqc); #endif } int finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, struct filecaps *fcaps) { struct filedesc *fdp = td->td_proc->p_fd; int error; MPASS(fd != NULL); FILEDESC_XLOCK(fdp); error = fdalloc(td, 0, fd); if (__predict_true(error == 0)) { _finstall(fdp, fp, *fd, flags, fcaps); } FILEDESC_XUNLOCK(fdp); return (error); } int finstall(struct thread *td, struct file *fp, int *fd, int flags, struct filecaps *fcaps) { int error; MPASS(fd != NULL); if (!fhold(fp)) return (EBADF); error = finstall_refed(td, fp, fd, flags, fcaps); if (__predict_false(error != 0)) { fdrop(fp, td); } return (error); } /* * Build a new filedesc structure from another. * * If fdp is not NULL, return with it shared locked. */ struct filedesc * fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) { struct filedesc0 *newfdp0; struct filedesc *newfdp; if (prepfiles) MPASS(lastfile != NULL); else MPASS(lastfile == NULL); newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); newfdp = &newfdp0->fd_fd; /* Create the file descriptor table. */ FILEDESC_LOCK_INIT(newfdp); refcount_init(&newfdp->fd_refcnt, 1); refcount_init(&newfdp->fd_holdcnt, 1); newfdp->fd_map = newfdp0->fd_dmap; newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; newfdp->fd_files->fdt_nfiles = NDFILE; if (fdp == NULL) return (newfdp); FILEDESC_SLOCK(fdp); if (!prepfiles) { FILEDESC_SUNLOCK(fdp); return (newfdp); } for (;;) { *lastfile = fdlastfile(fdp); if (*lastfile < newfdp->fd_nfiles) break; FILEDESC_SUNLOCK(fdp); fdgrowtable(newfdp, *lastfile + 1); FILEDESC_SLOCK(fdp); } return (newfdp); } /* * Build a pwddesc structure from another. * Copy the current, root, and jail root vnode references. * * If pdp is not NULL, return with it shared locked. */ struct pwddesc * pdinit(struct pwddesc *pdp, bool keeplock) { struct pwddesc *newpdp; struct pwd *newpwd; newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); PWDDESC_LOCK_INIT(newpdp); refcount_init(&newpdp->pd_refcount, 1); newpdp->pd_cmask = CMASK; if (pdp == NULL) { newpwd = pwd_alloc(); smr_serialized_store(&newpdp->pd_pwd, newpwd, true); return (newpdp); } PWDDESC_XLOCK(pdp); newpwd = pwd_hold_pwddesc(pdp); smr_serialized_store(&newpdp->pd_pwd, newpwd, true); if (!keeplock) PWDDESC_XUNLOCK(pdp); return (newpdp); } /* * Hold either filedesc or pwddesc of the passed process. * * The process lock is used to synchronize against the target exiting and * freeing the data. * * Clearing can be ilustrated in 3 steps: * 1. set the pointer to NULL. Either routine can race against it, hence * atomic_load_ptr. * 2. observe the process lock as not taken. Until then fdhold/pdhold can * race to either still see the pointer or find NULL. It is still safe to * grab a reference as clearing is stalled. * 3. after the lock is observed as not taken, any fdhold/pdhold calls are * guaranteed to see NULL, making it safe to finish clearing */ static struct filedesc * fdhold(struct proc *p) { struct filedesc *fdp; PROC_LOCK_ASSERT(p, MA_OWNED); fdp = atomic_load_ptr(&p->p_fd); if (fdp != NULL) refcount_acquire(&fdp->fd_holdcnt); return (fdp); } static struct pwddesc * pdhold(struct proc *p) { struct pwddesc *pdp; PROC_LOCK_ASSERT(p, MA_OWNED); pdp = atomic_load_ptr(&p->p_pd); if (pdp != NULL) refcount_acquire(&pdp->pd_refcount); return (pdp); } static void fddrop(struct filedesc *fdp) { if (refcount_load(&fdp->fd_holdcnt) > 1) { if (refcount_release(&fdp->fd_holdcnt) == 0) return; } FILEDESC_LOCK_DESTROY(fdp); uma_zfree(filedesc0_zone, fdp); } static void pddrop(struct pwddesc *pdp) { struct pwd *pwd; if (refcount_release_if_not_last(&pdp->pd_refcount)) return; PWDDESC_XLOCK(pdp); if (refcount_release(&pdp->pd_refcount) == 0) { PWDDESC_XUNLOCK(pdp); return; } pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); pwd_set(pdp, NULL); PWDDESC_XUNLOCK(pdp); pwd_drop(pwd); PWDDESC_LOCK_DESTROY(pdp); free(pdp, M_PWDDESC); } /* * Share a filedesc structure. */ struct filedesc * fdshare(struct filedesc *fdp) { refcount_acquire(&fdp->fd_refcnt); return (fdp); } /* * Share a pwddesc structure. */ struct pwddesc * pdshare(struct pwddesc *pdp) { refcount_acquire(&pdp->pd_refcount); return (pdp); } /* * Unshare a filedesc structure, if necessary by making a copy */ void fdunshare(struct thread *td) { struct filedesc *tmp; struct proc *p = td->td_proc; if (refcount_load(&p->p_fd->fd_refcnt) == 1) return; tmp = fdcopy(p->p_fd); fdescfree(td); p->p_fd = tmp; } /* * Unshare a pwddesc structure. */ void pdunshare(struct thread *td) { struct pwddesc *pdp; struct proc *p; p = td->td_proc; /* Not shared. */ if (p->p_pd->pd_refcount == 1) return; pdp = pdcopy(p->p_pd); pdescfree(td); p->p_pd = pdp; } void fdinstall_remapped(struct thread *td, struct filedesc *fdp) { fdescfree(td); td->td_proc->p_fd = fdp; } /* * Copy a filedesc structure. A NULL pointer in returns a NULL reference, * this is to ease callers, not catch errors. */ struct filedesc * fdcopy(struct filedesc *fdp) { struct filedesc *newfdp; struct filedescent *nfde, *ofde; int i, lastfile; MPASS(fdp != NULL); newfdp = fdinit(fdp, true, &lastfile); /* copy all passable descriptors (i.e. not kqueue) */ newfdp->fd_freefile = -1; for (i = 0; i <= lastfile; ++i) { ofde = &fdp->fd_ofiles[i]; if (ofde->fde_file == NULL || (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || !fhold(ofde->fde_file)) { if (newfdp->fd_freefile == -1) newfdp->fd_freefile = i; continue; } nfde = &newfdp->fd_ofiles[i]; *nfde = *ofde; filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); fdused_init(newfdp, i); } if (newfdp->fd_freefile == -1) newfdp->fd_freefile = i; FILEDESC_SUNLOCK(fdp); return (newfdp); } /* * Copy a pwddesc structure. */ struct pwddesc * pdcopy(struct pwddesc *pdp) { struct pwddesc *newpdp; MPASS(pdp != NULL); newpdp = pdinit(pdp, true); newpdp->pd_cmask = pdp->pd_cmask; PWDDESC_XUNLOCK(pdp); return (newpdp); } /* * Copies a filedesc structure, while remapping all file descriptors * stored inside using a translation table. * * File descriptors are copied over to the new file descriptor table, * regardless of whether the close-on-exec flag is set. */ int fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, struct filedesc **ret) { struct filedesc *newfdp; struct filedescent *nfde, *ofde; int error, i, lastfile; MPASS(fdp != NULL); newfdp = fdinit(fdp, true, &lastfile); if (nfds > lastfile + 1) { /* New table cannot be larger than the old one. */ error = E2BIG; goto bad; } /* Copy all passable descriptors (i.e. not kqueue). */ newfdp->fd_freefile = nfds; for (i = 0; i < nfds; ++i) { if (fds[i] < 0 || fds[i] > lastfile) { /* File descriptor out of bounds. */ error = EBADF; goto bad; } ofde = &fdp->fd_ofiles[fds[i]]; if (ofde->fde_file == NULL) { /* Unused file descriptor. */ error = EBADF; goto bad; } if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { /* File descriptor cannot be passed. */ error = EINVAL; goto bad; } if (!fhold(ofde->fde_file)) { error = EBADF; goto bad; } nfde = &newfdp->fd_ofiles[i]; *nfde = *ofde; filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); fdused_init(newfdp, i); } FILEDESC_SUNLOCK(fdp); *ret = newfdp; return (0); bad: FILEDESC_SUNLOCK(fdp); fdescfree_remapped(newfdp); return (error); } /* * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. * one of processes using it exits) and the table used to be shared. */ static void fdclearlocks(struct thread *td) { struct filedesc *fdp; struct filedesc_to_leader *fdtol; struct flock lf; struct file *fp; struct proc *p; struct vnode *vp; int i, lastfile; p = td->td_proc; fdp = p->p_fd; fdtol = p->p_fdtol; MPASS(fdtol != NULL); FILEDESC_XLOCK(fdp); KASSERT(fdtol->fdl_refcount > 0, ("filedesc_to_refcount botch: fdl_refcount=%d", fdtol->fdl_refcount)); if (fdtol->fdl_refcount == 1 && (p->p_leader->p_flag & P_ADVLOCK) != 0) { lastfile = fdlastfile(fdp); for (i = 0; i <= lastfile; i++) { fp = fdp->fd_ofiles[i].fde_file; if (fp == NULL || fp->f_type != DTYPE_VNODE || !fhold(fp)) continue; FILEDESC_XUNLOCK(fdp); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; vp = fp->f_vnode; (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, &lf, F_POSIX); FILEDESC_XLOCK(fdp); fdrop(fp, td); } } retry: if (fdtol->fdl_refcount == 1) { if (fdp->fd_holdleaderscount > 0 && (p->p_leader->p_flag & P_ADVLOCK) != 0) { /* * close() or kern_dup() has cleared a reference * in a shared file descriptor table. */ fdp->fd_holdleaderswakeup = 1; sx_sleep(&fdp->fd_holdleaderscount, FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); goto retry; } if (fdtol->fdl_holdcount > 0) { /* * Ensure that fdtol->fdl_leader remains * valid in closef(). */ fdtol->fdl_wakeup = 1; sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); goto retry; } } fdtol->fdl_refcount--; if (fdtol->fdl_refcount == 0 && fdtol->fdl_holdcount == 0) { fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; fdtol->fdl_prev->fdl_next = fdtol->fdl_next; } else fdtol = NULL; p->p_fdtol = NULL; FILEDESC_XUNLOCK(fdp); if (fdtol != NULL) free(fdtol, M_FILEDESC_TO_LEADER); } /* * Release a filedesc structure. */ static void fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) { struct filedesc0 *fdp0; struct freetable *ft, *tft; struct filedescent *fde; struct file *fp; int i, lastfile; KASSERT(refcount_load(&fdp->fd_refcnt) == 0, ("%s: fd table %p carries references", __func__, fdp)); /* * Serialize with threads iterating over the table, if any. */ if (refcount_load(&fdp->fd_holdcnt) > 1) { FILEDESC_XLOCK(fdp); FILEDESC_XUNLOCK(fdp); } lastfile = fdlastfile_single(fdp); for (i = 0; i <= lastfile; i++) { fde = &fdp->fd_ofiles[i]; fp = fde->fde_file; if (fp != NULL) { fdefree_last(fde); if (needclose) (void) closef(fp, td); else fdrop(fp, td); } } if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) free(fdp->fd_map, M_FILEDESC); if (fdp->fd_nfiles > NDFILE) free(fdp->fd_files, M_FILEDESC); fdp0 = (struct filedesc0 *)fdp; SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) free(ft->ft_table, M_FILEDESC); fddrop(fdp); } void fdescfree(struct thread *td) { struct proc *p; struct filedesc *fdp; p = td->td_proc; fdp = p->p_fd; MPASS(fdp != NULL); #ifdef RACCT if (RACCT_ENABLED()) racct_set_unlocked(p, RACCT_NOFILE, 0); #endif if (p->p_fdtol != NULL) fdclearlocks(td); /* * Check fdhold for an explanation. */ atomic_store_ptr(&p->p_fd, NULL); atomic_thread_fence_seq_cst(); PROC_WAIT_UNLOCKED(p); if (refcount_release(&fdp->fd_refcnt) == 0) return; fdescfree_fds(td, fdp, 1); } void pdescfree(struct thread *td) { struct proc *p; struct pwddesc *pdp; p = td->td_proc; pdp = p->p_pd; MPASS(pdp != NULL); /* * Check pdhold for an explanation. */ atomic_store_ptr(&p->p_pd, NULL); atomic_thread_fence_seq_cst(); PROC_WAIT_UNLOCKED(p); pddrop(pdp); } void fdescfree_remapped(struct filedesc *fdp) { #ifdef INVARIANTS /* fdescfree_fds() asserts that fd_refcnt == 0. */ if (!refcount_release(&fdp->fd_refcnt)) panic("%s: fd table %p has extra references", __func__, fdp); #endif fdescfree_fds(curthread, fdp, 0); } /* * For setugid programs, we don't want to people to use that setugidness * to generate error messages which write to a file which otherwise would * otherwise be off-limits to the process. We check for filesystems where * the vnode can change out from under us after execve (like [lin]procfs). * * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is * sufficient. We also don't check for setugidness since we know we are. */ static bool is_unsafe(struct file *fp) { struct vnode *vp; if (fp->f_type != DTYPE_VNODE) return (false); vp = fp->f_vnode; return ((vp->v_vflag & VV_PROCDEP) != 0); } /* * Make this setguid thing safe, if at all possible. */ void fdsetugidsafety(struct thread *td) { struct filedesc *fdp; struct file *fp; int i; fdp = td->td_proc->p_fd; KASSERT(refcount_load(&fdp->fd_refcnt) == 1, ("the fdtable should not be shared")); MPASS(fdp->fd_nfiles >= 3); for (i = 0; i <= 2; i++) { fp = fdp->fd_ofiles[i].fde_file; if (fp != NULL && is_unsafe(fp)) { FILEDESC_XLOCK(fdp); knote_fdclose(td, i); /* * NULL-out descriptor prior to close to avoid * a race while close blocks. */ fdfree(fdp, i); FILEDESC_XUNLOCK(fdp); (void) closef(fp, td); } } } /* * If a specific file object occupies a specific file descriptor, close the * file descriptor entry and drop a reference on the file object. This is a * convenience function to handle a subsequent error in a function that calls * falloc() that handles the race that another thread might have closed the * file descriptor out from under the thread creating the file object. */ void fdclose(struct thread *td, struct file *fp, int idx) { struct filedesc *fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); if (fdp->fd_ofiles[idx].fde_file == fp) { fdfree(fdp, idx); FILEDESC_XUNLOCK(fdp); fdrop(fp, td); } else FILEDESC_XUNLOCK(fdp); } /* * Close any files on exec? */ void fdcloseexec(struct thread *td) { struct filedesc *fdp; struct filedescent *fde; struct file *fp; int i, lastfile; fdp = td->td_proc->p_fd; KASSERT(refcount_load(&fdp->fd_refcnt) == 1, ("the fdtable should not be shared")); lastfile = fdlastfile_single(fdp); for (i = 0; i <= lastfile; i++) { fde = &fdp->fd_ofiles[i]; fp = fde->fde_file; if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || (fde->fde_flags & UF_EXCLOSE))) { FILEDESC_XLOCK(fdp); fdfree(fdp, i); (void) closefp(fdp, i, fp, td, false, false); FILEDESC_UNLOCK_ASSERT(fdp); } } } /* * It is unsafe for set[ug]id processes to be started with file * descriptors 0..2 closed, as these descriptors are given implicit * significance in the Standard C library. fdcheckstd() will create a * descriptor referencing /dev/null for each of stdin, stdout, and * stderr that is not already open. */ int fdcheckstd(struct thread *td) { struct filedesc *fdp; register_t save; int i, error, devnull; fdp = td->td_proc->p_fd; KASSERT(refcount_load(&fdp->fd_refcnt) == 1, ("the fdtable should not be shared")); MPASS(fdp->fd_nfiles >= 3); devnull = -1; for (i = 0; i <= 2; i++) { if (fdp->fd_ofiles[i].fde_file != NULL) continue; save = td->td_retval[0]; if (devnull != -1) { error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); } else { error = kern_openat(td, AT_FDCWD, "/dev/null", UIO_SYSSPACE, O_RDWR, 0); if (error == 0) { devnull = td->td_retval[0]; KASSERT(devnull == i, ("we didn't get our fd")); } } td->td_retval[0] = save; if (error != 0) return (error); } return (0); } /* * Internal form of close. Decrement reference count on file structure. * Note: td may be NULL when closing a file that was being passed in a * message. */ int closef(struct file *fp, struct thread *td) { struct vnode *vp; struct flock lf; struct filedesc_to_leader *fdtol; struct filedesc *fdp; MPASS(td != NULL); /* * POSIX record locking dictates that any close releases ALL * locks owned by this process. This is handled by setting * a flag in the unlock to free ONLY locks obeying POSIX * semantics, and not to free BSD-style file locks. * If the descriptor was in a message, POSIX-style locks * aren't passed with the descriptor, and the thread pointer * will be NULL. Callers should be careful only to pass a * NULL thread pointer when there really is no owning * context that might have locks, or the locks will be * leaked. */ if (fp->f_type == DTYPE_VNODE) { vp = fp->f_vnode; if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, F_UNLCK, &lf, F_POSIX); } fdtol = td->td_proc->p_fdtol; if (fdtol != NULL) { /* * Handle special case where file descriptor table is * shared between multiple process leaders. */ fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); for (fdtol = fdtol->fdl_next; fdtol != td->td_proc->p_fdtol; fdtol = fdtol->fdl_next) { if ((fdtol->fdl_leader->p_flag & P_ADVLOCK) == 0) continue; fdtol->fdl_holdcount++; FILEDESC_XUNLOCK(fdp); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; vp = fp->f_vnode; (void) VOP_ADVLOCK(vp, (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, F_POSIX); FILEDESC_XLOCK(fdp); fdtol->fdl_holdcount--; if (fdtol->fdl_holdcount == 0 && fdtol->fdl_wakeup != 0) { fdtol->fdl_wakeup = 0; wakeup(fdtol); } } FILEDESC_XUNLOCK(fdp); } } return (fdrop_close(fp, td)); } /* * Hack for file descriptor passing code. */ void closef_nothread(struct file *fp) { fdrop(fp, NULL); } /* * Initialize the file pointer with the specified properties. * * The ops are set with release semantics to be certain that the flags, type, * and data are visible when ops is. This is to prevent ops methods from being * called with bad data. */ void finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) { fp->f_data = data; fp->f_flag = flag; fp->f_type = type; atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); } void finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) { fp->f_seqcount[UIO_READ] = 1; fp->f_seqcount[UIO_WRITE] = 1; finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, data, ops); } int fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp) { struct filedescent *fde; int error; FILEDESC_LOCK_ASSERT(fdp); fde = fdeget_locked(fdp, fd); if (fde == NULL) { error = EBADF; goto out; } #ifdef CAPABILITIES error = cap_check(cap_rights_fde_inline(fde), needrightsp); if (error != 0) goto out; #endif if (havecapsp != NULL) filecaps_copy(&fde->fde_caps, havecapsp, true); *fpp = fde->fde_file; error = 0; out: return (error); } int fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp) { struct filedesc *fdp = td->td_proc->p_fd; int error; #ifndef CAPABILITIES error = fget_unlocked(fdp, fd, needrightsp, fpp); if (havecapsp != NULL && error == 0) filecaps_fill(havecapsp); #else struct file *fp; seqc_t seq; *fpp = NULL; for (;;) { error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); if (error != 0) return (error); if (havecapsp != NULL) { if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecapsp, false)) { fdrop(fp, td); goto get_locked; } } if (!fd_modified(fdp, fd, seq)) break; fdrop(fp, td); } *fpp = fp; return (0); get_locked: FILEDESC_SLOCK(fdp); error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); if (error == 0 && !fhold(*fpp)) error = EBADF; FILEDESC_SUNLOCK(fdp); #endif return (error); } #ifdef CAPABILITIES int fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) { const struct filedescent *fde; const struct fdescenttbl *fdt; struct filedesc *fdp; struct file *fp; struct vnode *vp; const cap_rights_t *haverights; cap_rights_t rights; seqc_t seq; VFS_SMR_ASSERT_ENTERED(); rights = *ndp->ni_rightsneeded; cap_rights_set_one(&rights, CAP_LOOKUP); fdp = curproc->p_fd; fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); seq = seqc_read_notmodify(fd_seqc(fdt, fd)); fde = &fdt->fdt_ofiles[fd]; haverights = cap_rights_fde_inline(fde); fp = fde->fde_file; if (__predict_false(fp == NULL)) return (EAGAIN); if (__predict_false(cap_check_inline_transient(haverights, &rights))) return (EAGAIN); *fsearch = ((fp->f_flag & FSEARCH) != 0); vp = fp->f_vnode; if (__predict_false(vp == NULL || vp->v_type != VDIR)) { return (EAGAIN); } if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { return (EAGAIN); } /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) return (EAGAIN); /* * If file descriptor doesn't have all rights, * all lookups relative to it must also be * strictly relative. * * Not yet supported by fast path. */ CAP_ALL(&rights); if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || ndp->ni_filecaps.fc_nioctls != -1) { #ifdef notyet ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; #else return (EAGAIN); #endif } *vpp = vp; return (0); } #else int fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) { const struct fdescenttbl *fdt; struct filedesc *fdp; struct file *fp; struct vnode *vp; VFS_SMR_ASSERT_ENTERED(); fdp = curproc->p_fd; fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); fp = fdt->fdt_ofiles[fd].fde_file; if (__predict_false(fp == NULL)) return (EAGAIN); *fsearch = ((fp->f_flag & FSEARCH) != 0); vp = fp->f_vnode; if (__predict_false(vp == NULL || vp->v_type != VDIR)) { return (EAGAIN); } /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) return (EAGAIN); filecaps_fill(&ndp->ni_filecaps); *vpp = vp; return (0); } #endif int fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp) { #ifdef CAPABILITIES const struct filedescent *fde; #endif const struct fdescenttbl *fdt; struct file *fp; #ifdef CAPABILITIES seqc_t seq; cap_rights_t haverights; int error; #endif fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); /* * Fetch the descriptor locklessly. We avoid fdrop() races by * never raising a refcount above 0. To accomplish this we have * to use a cmpset loop rather than an atomic_add. The descriptor * must be re-verified once we acquire a reference to be certain * that the identity is still correct and we did not lose a race * due to preemption. */ for (;;) { #ifdef CAPABILITIES seq = seqc_read_notmodify(fd_seqc(fdt, fd)); fde = &fdt->fdt_ofiles[fd]; haverights = *cap_rights_fde_inline(fde); fp = fde->fde_file; if (!seqc_consistent(fd_seqc(fdt, fd), seq)) continue; #else fp = fdt->fdt_ofiles[fd].fde_file; #endif if (fp == NULL) return (EBADF); #ifdef CAPABILITIES error = cap_check_inline(&haverights, needrightsp); if (error != 0) return (error); #endif if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { /* * Force a reload. Other thread could reallocate the * table before this fd was closed, so it is possible * that there is a stale fp pointer in cached version. */ fdt = atomic_load_ptr(&fdp->fd_files); continue; } /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; #ifdef CAPABILITIES if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) #else if (fp == fdt->fdt_ofiles[fd].fde_file) #endif break; fdrop(fp, curthread); } *fpp = fp; if (seqp != NULL) { #ifdef CAPABILITIES *seqp = seq; #endif } return (0); } /* * See the comments in fget_unlocked_seq for an explanation of how this works. * * This is a simplified variant which bails out to the aforementioned routine * if anything goes wrong. In practice this only happens when userspace is * racing with itself. */ int fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp) { #ifdef CAPABILITIES const struct filedescent *fde; #endif const struct fdescenttbl *fdt; struct file *fp; #ifdef CAPABILITIES seqc_t seq; const cap_rights_t *haverights; #endif fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); #ifdef CAPABILITIES seq = seqc_read_notmodify(fd_seqc(fdt, fd)); fde = &fdt->fdt_ofiles[fd]; haverights = cap_rights_fde_inline(fde); fp = fde->fde_file; #else fp = fdt->fdt_ofiles[fd].fde_file; #endif if (__predict_false(fp == NULL)) goto out_fallback; #ifdef CAPABILITIES if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) goto out_fallback; #endif if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) goto out_fallback; /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; #ifdef CAPABILITIES if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) #else if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) #endif goto out_fdrop; *fpp = fp; return (0); out_fdrop: fdrop(fp, curthread); out_fallback: return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); } /* * Translate fd -> file when the caller guarantees the file descriptor table * can't be changed by others. * * Note this does not mean the file object itself is only visible to the caller, * merely that it wont disappear without having to be referenced. * * Must be paired with fput_only_user. */ #ifdef CAPABILITIES int fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp) { const struct filedescent *fde; const struct fdescenttbl *fdt; const cap_rights_t *haverights; struct file *fp; int error; MPASS(FILEDESC_IS_ONLY_USER(fdp)); if (__predict_false(fd >= fdp->fd_nfiles)) return (EBADF); fdt = fdp->fd_files; fde = &fdt->fdt_ofiles[fd]; fp = fde->fde_file; if (__predict_false(fp == NULL)) return (EBADF); MPASS(refcount_load(&fp->f_count) > 0); haverights = cap_rights_fde_inline(fde); error = cap_check_inline(haverights, needrightsp); if (__predict_false(error != 0)) return (error); *fpp = fp; return (0); } #else int fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp) { struct file *fp; MPASS(FILEDESC_IS_ONLY_USER(fdp)); if (__predict_false(fd >= fdp->fd_nfiles)) return (EBADF); fp = fdp->fd_ofiles[fd].fde_file; if (__predict_false(fp == NULL)) return (EBADF); MPASS(refcount_load(&fp->f_count) > 0); *fpp = fp; return (0); } #endif /* * Extract the file pointer associated with the specified descriptor for the * current user process. * * If the descriptor doesn't exist or doesn't match 'flags', EBADF is * returned. * * File's rights will be checked against the capability rights mask. * * If an error occurred the non-zero error is returned and *fpp is set to * NULL. Otherwise *fpp is held and set and zero is returned. Caller is * responsible for fdrop(). */ static __inline int _fget(struct thread *td, int fd, struct file **fpp, int flags, cap_rights_t *needrightsp) { struct filedesc *fdp; struct file *fp; int error; *fpp = NULL; fdp = td->td_proc->p_fd; error = fget_unlocked(fdp, fd, needrightsp, &fp); if (__predict_false(error != 0)) return (error); if (__predict_false(fp->f_ops == &badfileops)) { fdrop(fp, td); return (EBADF); } /* * FREAD and FWRITE failure return EBADF as per POSIX. */ error = 0; switch (flags) { case FREAD: case FWRITE: if ((fp->f_flag & flags) == 0) error = EBADF; break; case FEXEC: if ((fp->f_flag & (FREAD | FEXEC)) == 0 || ((fp->f_flag & FWRITE) != 0)) error = EBADF; break; case 0: break; default: KASSERT(0, ("wrong flags")); } if (error != 0) { fdrop(fp, td); return (error); } *fpp = fp; return (0); } int fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, 0, rightsp)); } int fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, struct file **fpp) { int error; #ifndef CAPABILITIES error = _fget(td, fd, fpp, 0, rightsp); if (maxprotp != NULL) *maxprotp = VM_PROT_ALL; return (error); #else cap_rights_t fdrights; struct filedesc *fdp; struct file *fp; seqc_t seq; *fpp = NULL; fdp = td->td_proc->p_fd; MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); for (;;) { error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); if (__predict_false(error != 0)) return (error); if (__predict_false(fp->f_ops == &badfileops)) { fdrop(fp, td); return (EBADF); } if (maxprotp != NULL) fdrights = *cap_rights(fdp, fd); if (!fd_modified(fdp, fd, seq)) break; fdrop(fp, td); } /* * If requested, convert capability rights to access flags. */ if (maxprotp != NULL) *maxprotp = cap_rights_to_vmprot(&fdrights); *fpp = fp; return (0); #endif } int fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, FREAD, rightsp)); } int fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, FWRITE, rightsp)); } int fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, struct file **fpp) { struct filedesc *fdp = td->td_proc->p_fd; #ifndef CAPABILITIES return (fget_unlocked(fdp, fd, rightsp, fpp)); #else struct file *fp; int error; seqc_t seq; *fpp = NULL; MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); for (;;) { error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); if (error != 0) return (error); error = cap_fcntl_check(fdp, fd, needfcntl); if (!fd_modified(fdp, fd, seq)) break; fdrop(fp, td); } if (error != 0) { fdrop(fp, td); return (error); } *fpp = fp; return (0); #endif } /* * Like fget() but loads the underlying vnode, or returns an error if the * descriptor does not represent a vnode. Note that pipes use vnodes but * never have VM objects. The returned vnode will be vref()'d. * * XXX: what about the unused flags ? */ static __inline int _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, struct vnode **vpp) { struct file *fp; int error; *vpp = NULL; error = _fget(td, fd, &fp, flags, needrightsp); if (error != 0) return (error); if (fp->f_vnode == NULL) { error = EINVAL; } else { *vpp = fp->f_vnode; vref(*vpp); } fdrop(fp, td); return (error); } int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, 0, rightsp, vpp)); } int fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, struct filecaps *havecaps, struct vnode **vpp) { struct filecaps caps; struct file *fp; int error; error = fget_cap(td, fd, needrightsp, &fp, &caps); if (error != 0) return (error); if (fp->f_ops == &badfileops) { error = EBADF; goto out; } if (fp->f_vnode == NULL) { error = EINVAL; goto out; } *havecaps = caps; *vpp = fp->f_vnode; vref(*vpp); fdrop(fp, td); return (0); out: filecaps_free(&caps); fdrop(fp, td); return (error); } int fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FREAD, rightsp, vpp)); } int fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); } #ifdef notyet int fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); } #endif /* * Handle the last reference to a file being closed. * * Without the noinline attribute clang keeps inlining the func thorough this * file when fdrop is used. */ int __noinline _fdrop(struct file *fp, struct thread *td) { int error; #ifdef INVARIANTS int count; count = refcount_load(&fp->f_count); if (count != 0) panic("fdrop: fp %p count %d", fp, count); #endif error = fo_close(fp, td); atomic_subtract_int(&openfiles, 1); crfree(fp->f_cred); free(fp->f_advice, M_FADVISE); uma_zfree(file_zone, fp); return (error); } /* * Apply an advisory lock on a file descriptor. * * Just attempt to get a record lock of the requested type on the entire file * (l_whence = SEEK_SET, l_start = 0, l_len = 0). */ #ifndef _SYS_SYSPROTO_H_ struct flock_args { int fd; int how; }; #endif /* ARGSUSED */ int sys_flock(struct thread *td, struct flock_args *uap) { struct file *fp; struct vnode *vp; struct flock lf; int error; error = fget(td, uap->fd, &cap_flock_rights, &fp); if (error != 0) return (error); - if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { - fdrop(fp, td); - return (EOPNOTSUPP); + error = EOPNOTSUPP; + if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { + goto done; + } + if (fp->f_ops == &path_fileops) { + goto done; } + error = 0; vp = fp->f_vnode; lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; if (uap->how & LOCK_UN) { lf.l_type = F_UNLCK; atomic_clear_int(&fp->f_flag, FHASLOCK); error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); - goto done2; + goto done; } if (uap->how & LOCK_EX) lf.l_type = F_WRLCK; else if (uap->how & LOCK_SH) lf.l_type = F_RDLCK; else { error = EBADF; - goto done2; + goto done; } atomic_set_int(&fp->f_flag, FHASLOCK); error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); -done2: +done: fdrop(fp, td); return (error); } /* * Duplicate the specified descriptor to a free descriptor. */ int dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, int openerror, int *indxp) { struct filedescent *newfde, *oldfde; struct file *fp; u_long *ioctls; int error, indx; KASSERT(openerror == ENODEV || openerror == ENXIO, ("unexpected error %d in %s", openerror, __func__)); /* * If the to-be-dup'd fd number is greater than the allowed number * of file descriptors, or the fd to be dup'd has already been * closed, then reject. */ FILEDESC_XLOCK(fdp); if ((fp = fget_locked(fdp, dfd)) == NULL) { FILEDESC_XUNLOCK(fdp); return (EBADF); } error = fdalloc(td, 0, &indx); if (error != 0) { FILEDESC_XUNLOCK(fdp); return (error); } /* * There are two cases of interest here. * * For ENODEV simply dup (dfd) to file descriptor (indx) and return. * * For ENXIO steal away the file structure from (dfd) and store it in * (indx). (dfd) is effectively closed by this operation. */ switch (openerror) { case ENODEV: /* * Check that the mode the file is being opened for is a * subset of the mode of the existing descriptor. */ if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { fdunused(fdp, indx); FILEDESC_XUNLOCK(fdp); return (EACCES); } if (!fhold(fp)) { fdunused(fdp, indx); FILEDESC_XUNLOCK(fdp); return (EBADF); } newfde = &fdp->fd_ofiles[indx]; oldfde = &fdp->fd_ofiles[dfd]; ioctls = filecaps_copy_prep(&oldfde->fde_caps); #ifdef CAPABILITIES seqc_write_begin(&newfde->fde_seqc); #endif memcpy(newfde, oldfde, fde_change_size); filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, ioctls); #ifdef CAPABILITIES seqc_write_end(&newfde->fde_seqc); #endif break; case ENXIO: /* * Steal away the file pointer from dfd and stuff it into indx. */ newfde = &fdp->fd_ofiles[indx]; oldfde = &fdp->fd_ofiles[dfd]; #ifdef CAPABILITIES seqc_write_begin(&newfde->fde_seqc); #endif memcpy(newfde, oldfde, fde_change_size); oldfde->fde_file = NULL; fdunused(fdp, dfd); #ifdef CAPABILITIES seqc_write_end(&newfde->fde_seqc); #endif break; } FILEDESC_XUNLOCK(fdp); *indxp = indx; return (0); } /* * This sysctl determines if we will allow a process to chroot(2) if it * has a directory open: * 0: disallowed for all processes. * 1: allowed for processes that were not already chroot(2)'ed. * 2: allowed for all processes. */ static int chroot_allow_open_directories = 1; SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, &chroot_allow_open_directories, 0, "Allow a process to chroot(2) if it has a directory open"); /* * Helper function for raised chroot(2) security function: Refuse if * any filedescriptors are open directories. */ static int chroot_refuse_vdir_fds(struct filedesc *fdp) { struct vnode *vp; struct file *fp; int fd, lastfile; FILEDESC_LOCK_ASSERT(fdp); lastfile = fdlastfile(fdp); for (fd = 0; fd <= lastfile; fd++) { fp = fget_locked(fdp, fd); if (fp == NULL) continue; if (fp->f_type == DTYPE_VNODE) { vp = fp->f_vnode; if (vp->v_type == VDIR) return (EPERM); } } return (0); } static void pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) { if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { vrefact(oldpwd->pwd_cdir); newpwd->pwd_cdir = oldpwd->pwd_cdir; } if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { vrefact(oldpwd->pwd_rdir); newpwd->pwd_rdir = oldpwd->pwd_rdir; } if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { vrefact(oldpwd->pwd_jdir); newpwd->pwd_jdir = oldpwd->pwd_jdir; } } struct pwd * pwd_hold_pwddesc(struct pwddesc *pdp) { struct pwd *pwd; PWDDESC_ASSERT_XLOCKED(pdp); pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (pwd != NULL) refcount_acquire(&pwd->pwd_refcount); return (pwd); } bool pwd_hold_smr(struct pwd *pwd) { MPASS(pwd != NULL); if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { return (true); } return (false); } struct pwd * pwd_hold(struct thread *td) { struct pwddesc *pdp; struct pwd *pwd; pdp = td->td_proc->p_pd; vfs_smr_enter(); pwd = vfs_smr_entered_load(&pdp->pd_pwd); if (pwd_hold_smr(pwd)) { vfs_smr_exit(); return (pwd); } vfs_smr_exit(); PWDDESC_XLOCK(pdp); pwd = pwd_hold_pwddesc(pdp); MPASS(pwd != NULL); PWDDESC_XUNLOCK(pdp); return (pwd); } static struct pwd * pwd_alloc(void) { struct pwd *pwd; pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); bzero(pwd, sizeof(*pwd)); refcount_init(&pwd->pwd_refcount, 1); return (pwd); } void pwd_drop(struct pwd *pwd) { if (!refcount_release(&pwd->pwd_refcount)) return; if (pwd->pwd_cdir != NULL) vrele(pwd->pwd_cdir); if (pwd->pwd_rdir != NULL) vrele(pwd->pwd_rdir); if (pwd->pwd_jdir != NULL) vrele(pwd->pwd_jdir); uma_zfree_smr(pwd_zone, pwd); } /* * The caller is responsible for invoking priv_check() and * mac_vnode_check_chroot() to authorize this operation. */ int pwd_chroot(struct thread *td, struct vnode *vp) { struct pwddesc *pdp; struct filedesc *fdp; struct pwd *newpwd, *oldpwd; int error; fdp = td->td_proc->p_fd; pdp = td->td_proc->p_pd; newpwd = pwd_alloc(); FILEDESC_SLOCK(fdp); PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (chroot_allow_open_directories == 0 || (chroot_allow_open_directories == 1 && oldpwd->pwd_rdir != rootvnode)) { error = chroot_refuse_vdir_fds(fdp); FILEDESC_SUNLOCK(fdp); if (error != 0) { PWDDESC_XUNLOCK(pdp); pwd_drop(newpwd); return (error); } } else { FILEDESC_SUNLOCK(fdp); } vrefact(vp); newpwd->pwd_rdir = vp; if (oldpwd->pwd_jdir == NULL) { vrefact(vp); newpwd->pwd_jdir = vp; } pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); return (0); } void pwd_chdir(struct thread *td, struct vnode *vp) { struct pwddesc *pdp; struct pwd *newpwd, *oldpwd; VNPASS(vp->v_usecount > 0, vp); newpwd = pwd_alloc(); pdp = td->td_proc->p_pd; PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); newpwd->pwd_cdir = vp; pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); } /* * jail_attach(2) changes both root and working directories. */ int pwd_chroot_chdir(struct thread *td, struct vnode *vp) { struct pwddesc *pdp; struct filedesc *fdp; struct pwd *newpwd, *oldpwd; int error; fdp = td->td_proc->p_fd; pdp = td->td_proc->p_pd; newpwd = pwd_alloc(); FILEDESC_SLOCK(fdp); PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); error = chroot_refuse_vdir_fds(fdp); FILEDESC_SUNLOCK(fdp); if (error != 0) { PWDDESC_XUNLOCK(pdp); pwd_drop(newpwd); return (error); } vrefact(vp); newpwd->pwd_rdir = vp; vrefact(vp); newpwd->pwd_cdir = vp; if (oldpwd->pwd_jdir == NULL) { vrefact(vp); newpwd->pwd_jdir = vp; } pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); return (0); } void pwd_ensure_dirs(void) { struct pwddesc *pdp; struct pwd *oldpwd, *newpwd; pdp = curproc->p_pd; PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { PWDDESC_XUNLOCK(pdp); return; } PWDDESC_XUNLOCK(pdp); newpwd = pwd_alloc(); PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); pwd_fill(oldpwd, newpwd); if (newpwd->pwd_cdir == NULL) { vrefact(rootvnode); newpwd->pwd_cdir = rootvnode; } if (newpwd->pwd_rdir == NULL) { vrefact(rootvnode); newpwd->pwd_rdir = rootvnode; } pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); } void pwd_set_rootvnode(void) { struct pwddesc *pdp; struct pwd *oldpwd, *newpwd; pdp = curproc->p_pd; newpwd = pwd_alloc(); PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); vrefact(rootvnode); newpwd->pwd_cdir = rootvnode; vrefact(rootvnode); newpwd->pwd_rdir = rootvnode; pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); } /* * Scan all active processes and prisons to see if any of them have a current * or root directory of `olddp'. If so, replace them with the new mount point. */ void mountcheckdirs(struct vnode *olddp, struct vnode *newdp) { struct pwddesc *pdp; struct pwd *newpwd, *oldpwd; struct prison *pr; struct proc *p; int nrele; if (vrefcnt(olddp) == 1) return; nrele = 0; newpwd = pwd_alloc(); sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); pdp = pdhold(p); PROC_UNLOCK(p); if (pdp == NULL) continue; PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (oldpwd == NULL || (oldpwd->pwd_cdir != olddp && oldpwd->pwd_rdir != olddp && oldpwd->pwd_jdir != olddp)) { PWDDESC_XUNLOCK(pdp); pddrop(pdp); continue; } if (oldpwd->pwd_cdir == olddp) { vrefact(newdp); newpwd->pwd_cdir = newdp; } if (oldpwd->pwd_rdir == olddp) { vrefact(newdp); newpwd->pwd_rdir = newdp; } if (oldpwd->pwd_jdir == olddp) { vrefact(newdp); newpwd->pwd_jdir = newdp; } pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); pddrop(pdp); newpwd = pwd_alloc(); } sx_sunlock(&allproc_lock); pwd_drop(newpwd); if (rootvnode == olddp) { vrefact(newdp); rootvnode = newdp; nrele++; } mtx_lock(&prison0.pr_mtx); if (prison0.pr_root == olddp) { vrefact(newdp); prison0.pr_root = newdp; nrele++; } mtx_unlock(&prison0.pr_mtx); sx_slock(&allprison_lock); TAILQ_FOREACH(pr, &allprison, pr_list) { mtx_lock(&pr->pr_mtx); if (pr->pr_root == olddp) { vrefact(newdp); pr->pr_root = newdp; nrele++; } mtx_unlock(&pr->pr_mtx); } sx_sunlock(&allprison_lock); while (nrele--) vrele(olddp); } struct filedesc_to_leader * filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) { struct filedesc_to_leader *fdtol; fdtol = malloc(sizeof(struct filedesc_to_leader), M_FILEDESC_TO_LEADER, M_WAITOK); fdtol->fdl_refcount = 1; fdtol->fdl_holdcount = 0; fdtol->fdl_wakeup = 0; fdtol->fdl_leader = leader; if (old != NULL) { FILEDESC_XLOCK(fdp); fdtol->fdl_next = old->fdl_next; fdtol->fdl_prev = old; old->fdl_next = fdtol; fdtol->fdl_next->fdl_prev = fdtol; FILEDESC_XUNLOCK(fdp); } else { fdtol->fdl_next = fdtol; fdtol->fdl_prev = fdtol; } return (fdtol); } static int sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) { NDSLOTTYPE *map; struct filedesc *fdp; u_int namelen; int count, off, minoff; namelen = arg2; if (namelen != 1) return (EINVAL); if (*(int *)arg1 != 0) return (EINVAL); fdp = curproc->p_fd; count = 0; FILEDESC_SLOCK(fdp); map = fdp->fd_map; off = NDSLOT(fdp->fd_nfiles - 1); for (minoff = NDSLOT(0); off >= minoff; --off) count += bitcountl(map[off]); FILEDESC_SUNLOCK(fdp); return (SYSCTL_OUT(req, &count, sizeof(count))); } static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, "Number of open file descriptors"); /* * Get file structures globally. */ static int sysctl_kern_file(SYSCTL_HANDLER_ARGS) { struct xfile xf; struct filedesc *fdp; struct file *fp; struct proc *p; int error, n, lastfile; error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); if (req->oldptr == NULL) { n = 0; sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state == PRS_NEW) { PROC_UNLOCK(p); continue; } fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) continue; /* overestimates sparse tables. */ n += fdp->fd_nfiles; fddrop(fdp); } sx_sunlock(&allproc_lock); return (SYSCTL_OUT(req, 0, n * sizeof(xf))); } error = 0; bzero(&xf, sizeof(xf)); xf.xf_size = sizeof(xf); sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state == PRS_NEW) { PROC_UNLOCK(p); continue; } if (p_cansee(req->td, p) != 0) { PROC_UNLOCK(p); continue; } xf.xf_pid = p->p_pid; xf.xf_uid = p->p_ucred->cr_uid; fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) continue; FILEDESC_SLOCK(fdp); lastfile = fdlastfile(fdp); for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; n++) { if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) continue; xf.xf_fd = n; xf.xf_file = (uintptr_t)fp; xf.xf_data = (uintptr_t)fp->f_data; xf.xf_vnode = (uintptr_t)fp->f_vnode; xf.xf_type = (uintptr_t)fp->f_type; xf.xf_count = refcount_load(&fp->f_count); xf.xf_msgcount = 0; xf.xf_offset = foffset_get(fp); xf.xf_flag = fp->f_flag; error = SYSCTL_OUT(req, &xf, sizeof(xf)); if (error) break; } FILEDESC_SUNLOCK(fdp); fddrop(fdp); if (error) break; } sx_sunlock(&allproc_lock); return (error); } SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); #ifdef KINFO_FILE_SIZE CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); #endif static int xlate_fflags(int fflags) { static const struct { int fflag; int kf_fflag; } fflags_table[] = { { FAPPEND, KF_FLAG_APPEND }, { FASYNC, KF_FLAG_ASYNC }, { FFSYNC, KF_FLAG_FSYNC }, { FHASLOCK, KF_FLAG_HASLOCK }, { FNONBLOCK, KF_FLAG_NONBLOCK }, { FREAD, KF_FLAG_READ }, { FWRITE, KF_FLAG_WRITE }, { O_CREAT, KF_FLAG_CREAT }, { O_DIRECT, KF_FLAG_DIRECT }, { O_EXCL, KF_FLAG_EXCL }, { O_EXEC, KF_FLAG_EXEC }, { O_EXLOCK, KF_FLAG_EXLOCK }, { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, { O_SHLOCK, KF_FLAG_SHLOCK }, { O_TRUNC, KF_FLAG_TRUNC } }; unsigned int i; int kflags; kflags = 0; for (i = 0; i < nitems(fflags_table); i++) if (fflags & fflags_table[i].fflag) kflags |= fflags_table[i].kf_fflag; return (kflags); } /* Trim unused data from kf_path by truncating the structure size. */ void pack_kinfo(struct kinfo_file *kif) { kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + strlen(kif->kf_path) + 1; kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); } static void export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, struct kinfo_file *kif, struct filedesc *fdp, int flags) { int error; bzero(kif, sizeof(*kif)); /* Set a default type to allow for empty fill_kinfo() methods. */ kif->kf_type = KF_TYPE_UNKNOWN; kif->kf_flags = xlate_fflags(fp->f_flag); if (rightsp != NULL) kif->kf_cap_rights = *rightsp; else cap_rights_init_zero(&kif->kf_cap_rights); kif->kf_fd = fd; kif->kf_ref_count = refcount_load(&fp->f_count); kif->kf_offset = foffset_get(fp); /* * This may drop the filedesc lock, so the 'fp' cannot be * accessed after this call. */ error = fo_fill_kinfo(fp, kif, fdp); if (error == 0) kif->kf_status |= KF_ATTR_VALID; if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) pack_kinfo(kif); else kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); } static void export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, struct kinfo_file *kif, int flags) { int error; bzero(kif, sizeof(*kif)); kif->kf_type = KF_TYPE_VNODE; error = vn_fill_kinfo_vnode(vp, kif); if (error == 0) kif->kf_status |= KF_ATTR_VALID; kif->kf_flags = xlate_fflags(fflags); cap_rights_init_zero(&kif->kf_cap_rights); kif->kf_fd = fd; kif->kf_ref_count = -1; kif->kf_offset = -1; if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) pack_kinfo(kif); else kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); vrele(vp); } struct export_fd_buf { struct filedesc *fdp; struct pwddesc *pdp; struct sbuf *sb; ssize_t remainder; struct kinfo_file kif; int flags; }; static int export_kinfo_to_sb(struct export_fd_buf *efbuf) { struct kinfo_file *kif; kif = &efbuf->kif; if (efbuf->remainder != -1) { if (efbuf->remainder < kif->kf_structsize) { /* Terminate export. */ efbuf->remainder = 0; return (0); } efbuf->remainder -= kif->kf_structsize; } return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); } static int export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, struct export_fd_buf *efbuf) { int error; if (efbuf->remainder == 0) return (0); export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, efbuf->flags); FILEDESC_SUNLOCK(efbuf->fdp); error = export_kinfo_to_sb(efbuf); FILEDESC_SLOCK(efbuf->fdp); return (error); } static int export_vnode_to_sb(struct vnode *vp, int fd, int fflags, struct export_fd_buf *efbuf) { int error; if (efbuf->remainder == 0) return (0); if (efbuf->pdp != NULL) PWDDESC_XUNLOCK(efbuf->pdp); export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); error = export_kinfo_to_sb(efbuf); if (efbuf->pdp != NULL) PWDDESC_XLOCK(efbuf->pdp); return (error); } /* * Store a process file descriptor information to sbuf. * * Takes a locked proc as argument, and returns with the proc unlocked. */ int kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, int flags) { struct file *fp; struct filedesc *fdp; struct pwddesc *pdp; struct export_fd_buf *efbuf; struct vnode *cttyvp, *textvp, *tracevp; struct pwd *pwd; int error, i, lastfile; cap_rights_t rights; PROC_LOCK_ASSERT(p, MA_OWNED); /* ktrace vnode */ tracevp = ktr_get_tracevp(p, true); /* text vnode */ textvp = p->p_textvp; if (textvp != NULL) vrefact(textvp); /* Controlling tty. */ cttyvp = NULL; if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { cttyvp = p->p_pgrp->pg_session->s_ttyvp; if (cttyvp != NULL) vrefact(cttyvp); } fdp = fdhold(p); pdp = pdhold(p); PROC_UNLOCK(p); efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); efbuf->fdp = NULL; efbuf->pdp = NULL; efbuf->sb = sb; efbuf->remainder = maxlen; efbuf->flags = flags; if (tracevp != NULL) export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, efbuf); if (textvp != NULL) export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); if (cttyvp != NULL) export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, efbuf); error = 0; if (pdp == NULL || fdp == NULL) goto fail; efbuf->fdp = fdp; efbuf->pdp = pdp; PWDDESC_XLOCK(pdp); pwd = pwd_hold_pwddesc(pdp); if (pwd != NULL) { /* working directory */ if (pwd->pwd_cdir != NULL) { vrefact(pwd->pwd_cdir); export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); } /* root directory */ if (pwd->pwd_rdir != NULL) { vrefact(pwd->pwd_rdir); export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); } /* jail directory */ if (pwd->pwd_jdir != NULL) { vrefact(pwd->pwd_jdir); export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); } } PWDDESC_XUNLOCK(pdp); if (pwd != NULL) pwd_drop(pwd); FILEDESC_SLOCK(fdp); lastfile = fdlastfile(fdp); for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) continue; #ifdef CAPABILITIES rights = *cap_rights(fdp, i); #else /* !CAPABILITIES */ rights = cap_no_rights; #endif /* * Create sysctl entry. It is OK to drop the filedesc * lock inside of export_file_to_sb() as we will * re-validate and re-evaluate its properties when the * loop continues. */ error = export_file_to_sb(fp, i, &rights, efbuf); if (error != 0 || efbuf->remainder == 0) break; } FILEDESC_SUNLOCK(fdp); fail: if (fdp != NULL) fddrop(fdp); if (pdp != NULL) pddrop(pdp); free(efbuf, M_TEMP); return (error); } #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) /* * Get per-process file descriptors for use by procstat(1), et al. */ static int sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) { struct sbuf sb; struct proc *p; ssize_t maxlen; u_int namelen; int error, error2, *name; namelen = arg2; if (namelen != 1) return (EINVAL); name = (int *)arg1; sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); sbuf_clear_flags(&sb, SBUF_INCLUDENUL); error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) { sbuf_delete(&sb); return (error); } maxlen = req->oldptr != NULL ? req->oldlen : -1; error = kern_proc_filedesc_out(p, &sb, maxlen, KERN_FILEDESC_PACK_KINFO); error2 = sbuf_finish(&sb); sbuf_delete(&sb); return (error != 0 ? error : error2); } #ifdef COMPAT_FREEBSD7 #ifdef KINFO_OFILE_SIZE CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); #endif static void kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) { okif->kf_structsize = sizeof(*okif); okif->kf_type = kif->kf_type; okif->kf_fd = kif->kf_fd; okif->kf_ref_count = kif->kf_ref_count; okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | KF_FLAG_DIRECT | KF_FLAG_HASLOCK); okif->kf_offset = kif->kf_offset; if (kif->kf_type == KF_TYPE_VNODE) okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; else okif->kf_vnode_type = KF_VTYPE_VNON; strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); if (kif->kf_type == KF_TYPE_SOCKET) { okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; } else { okif->kf_sa_local.ss_family = AF_UNSPEC; okif->kf_sa_peer.ss_family = AF_UNSPEC; } } static int export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) { int error; vrefact(vp); PWDDESC_XUNLOCK(pdp); export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); kinfo_to_okinfo(kif, okif); error = SYSCTL_OUT(req, okif, sizeof(*okif)); PWDDESC_XLOCK(pdp); return (error); } /* * Get per-process file descriptors for use by procstat(1), et al. */ static int sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) { struct kinfo_ofile *okif; struct kinfo_file *kif; struct filedesc *fdp; struct pwddesc *pdp; struct pwd *pwd; u_int namelen; int error, i, lastfile, *name; struct file *fp; struct proc *p; namelen = arg2; if (namelen != 1) return (EINVAL); name = (int *)arg1; error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) return (error); fdp = fdhold(p); if (fdp != NULL) pdp = pdhold(p); PROC_UNLOCK(p); if (fdp == NULL || pdp == NULL) { if (fdp != NULL) fddrop(fdp); return (ENOENT); } kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); PWDDESC_XLOCK(pdp); pwd = pwd_hold_pwddesc(pdp); if (pwd != NULL) { if (pwd->pwd_cdir != NULL) export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, okif, pdp, req); if (pwd->pwd_rdir != NULL) export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, okif, pdp, req); if (pwd->pwd_jdir != NULL) export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, okif, pdp, req); } PWDDESC_XUNLOCK(pdp); if (pwd != NULL) pwd_drop(pwd); FILEDESC_SLOCK(fdp); lastfile = fdlastfile(fdp); for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) continue; export_file_to_kinfo(fp, i, NULL, kif, fdp, KERN_FILEDESC_PACK_KINFO); FILEDESC_SUNLOCK(fdp); kinfo_to_okinfo(kif, okif); error = SYSCTL_OUT(req, okif, sizeof(*okif)); FILEDESC_SLOCK(fdp); if (error) break; } FILEDESC_SUNLOCK(fdp); fddrop(fdp); pddrop(pdp); free(kif, M_TEMP); free(okif, M_TEMP); return (0); } static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, "Process ofiledesc entries"); #endif /* COMPAT_FREEBSD7 */ int vntype_to_kinfo(int vtype) { struct { int vtype; int kf_vtype; } vtypes_table[] = { { VBAD, KF_VTYPE_VBAD }, { VBLK, KF_VTYPE_VBLK }, { VCHR, KF_VTYPE_VCHR }, { VDIR, KF_VTYPE_VDIR }, { VFIFO, KF_VTYPE_VFIFO }, { VLNK, KF_VTYPE_VLNK }, { VNON, KF_VTYPE_VNON }, { VREG, KF_VTYPE_VREG }, { VSOCK, KF_VTYPE_VSOCK } }; unsigned int i; /* * Perform vtype translation. */ for (i = 0; i < nitems(vtypes_table); i++) if (vtypes_table[i].vtype == vtype) return (vtypes_table[i].kf_vtype); return (KF_VTYPE_UNKNOWN); } static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, "Process filedesc entries"); /* * Store a process current working directory information to sbuf. * * Takes a locked proc as argument, and returns with the proc unlocked. */ int kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) { struct pwddesc *pdp; struct pwd *pwd; struct export_fd_buf *efbuf; struct vnode *cdir; int error; PROC_LOCK_ASSERT(p, MA_OWNED); pdp = pdhold(p); PROC_UNLOCK(p); if (pdp == NULL) return (EINVAL); efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); efbuf->pdp = pdp; efbuf->sb = sb; efbuf->remainder = maxlen; PWDDESC_XLOCK(pdp); pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); cdir = pwd->pwd_cdir; if (cdir == NULL) { error = EINVAL; } else { vrefact(cdir); error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); } PWDDESC_XUNLOCK(pdp); pddrop(pdp); free(efbuf, M_TEMP); return (error); } /* * Get per-process current working directory. */ static int sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) { struct sbuf sb; struct proc *p; ssize_t maxlen; u_int namelen; int error, error2, *name; namelen = arg2; if (namelen != 1) return (EINVAL); name = (int *)arg1; sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); sbuf_clear_flags(&sb, SBUF_INCLUDENUL); error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) { sbuf_delete(&sb); return (error); } maxlen = req->oldptr != NULL ? req->oldlen : -1; error = kern_proc_cwd_out(p, &sb, maxlen); error2 = sbuf_finish(&sb); sbuf_delete(&sb); return (error != 0 ? error : error2); } static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_cwd, "Process current working directory"); #ifdef DDB /* * For the purposes of debugging, generate a human-readable string for the * file type. */ static const char * file_type_to_name(short type) { switch (type) { case 0: return ("zero"); case DTYPE_VNODE: return ("vnode"); case DTYPE_SOCKET: return ("socket"); case DTYPE_PIPE: return ("pipe"); case DTYPE_FIFO: return ("fifo"); case DTYPE_KQUEUE: return ("kqueue"); case DTYPE_CRYPTO: return ("crypto"); case DTYPE_MQUEUE: return ("mqueue"); case DTYPE_SHM: return ("shm"); case DTYPE_SEM: return ("ksem"); case DTYPE_PTS: return ("pts"); case DTYPE_DEV: return ("dev"); case DTYPE_PROCDESC: return ("proc"); case DTYPE_EVENTFD: return ("eventfd"); case DTYPE_LINUXTFD: return ("ltimer"); default: return ("unkn"); } } /* * For the purposes of debugging, identify a process (if any, perhaps one of * many) that references the passed file in its file descriptor array. Return * NULL if none. */ static struct proc * file_to_first_proc(struct file *fp) { struct filedesc *fdp; struct proc *p; int n; FOREACH_PROC_IN_SYSTEM(p) { if (p->p_state == PRS_NEW) continue; fdp = p->p_fd; if (fdp == NULL) continue; for (n = 0; n < fdp->fd_nfiles; n++) { if (fp == fdp->fd_ofiles[n].fde_file) return (p); } } return (NULL); } static void db_print_file(struct file *fp, int header) { #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) struct proc *p; if (header) db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", "FCmd"); p = file_to_first_proc(fp); db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); #undef XPTRWIDTH } DB_SHOW_COMMAND(file, db_show_file) { struct file *fp; if (!have_addr) { db_printf("usage: show file \n"); return; } fp = (struct file *)addr; db_print_file(fp, 1); } DB_SHOW_COMMAND(files, db_show_files) { struct filedesc *fdp; struct file *fp; struct proc *p; int header; int n; header = 1; FOREACH_PROC_IN_SYSTEM(p) { if (p->p_state == PRS_NEW) continue; if ((fdp = p->p_fd) == NULL) continue; for (n = 0; n < fdp->fd_nfiles; ++n) { if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) continue; db_print_file(fp, header); header = 0; } } } #endif SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, &maxfilesperproc, 0, "Maximum files allowed open per process"); SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, &maxfiles, 0, "Maximum number of files"); SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, &openfiles, 0, "System-wide number of open files"); /* ARGSUSED*/ static void filelistinit(void *dummy) { file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); /* * XXXMJG this is a temporary hack due to boot ordering issues against * the vnode zone. */ vfs_smr = uma_zone_get_smr(pwd_zone); mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); } SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); /*-------------------------------------------------------------------*/ static int badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { return (EBADF); } static int badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) { return (EINVAL); } static int badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (0); } static int badfo_kqfilter(struct file *fp, struct knote *kn) { return (EBADF); } static int badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_close(struct file *fp, struct thread *td) { return (0); } static int badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, struct thread *td) { return (EBADF); } static int badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) { return (0); } struct fileops badfileops = { .fo_read = badfo_readwrite, .fo_write = badfo_readwrite, .fo_truncate = badfo_truncate, .fo_ioctl = badfo_ioctl, .fo_poll = badfo_poll, .fo_kqfilter = badfo_kqfilter, .fo_stat = badfo_stat, .fo_close = badfo_close, .fo_chmod = badfo_chmod, .fo_chown = badfo_chown, .fo_sendfile = badfo_sendfile, .fo_fill_kinfo = badfo_fill_kinfo, }; static int path_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (POLLNVAL); } static int path_close(struct file *fp, struct thread *td) { MPASS(fp->f_type == DTYPE_VNODE); fp->f_ops = &badfileops; vdrop(fp->f_vnode); return (0); } struct fileops path_fileops = { .fo_read = badfo_readwrite, .fo_write = badfo_readwrite, .fo_truncate = badfo_truncate, .fo_ioctl = badfo_ioctl, .fo_poll = path_poll, .fo_kqfilter = vn_kqfilter_opath, .fo_stat = vn_statfile, .fo_close = path_close, .fo_chmod = badfo_chmod, .fo_chown = badfo_chown, .fo_sendfile = badfo_sendfile, .fo_fill_kinfo = vn_fill_kinfo, .fo_flags = DFLAG_PASSABLE, }; int invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { return (EOPNOTSUPP); } int invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) { return (ENOTTY); } int invfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (poll_no_poll(events)); } int invfo_kqfilter(struct file *fp, struct knote *kn) { return (EINVAL); } int invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, struct thread *td) { return (EINVAL); } /*-------------------------------------------------------------------*/ /* * File Descriptor pseudo-device driver (/dev/fd/). * * Opening minor device N dup()s the file (if any) connected to file * descriptor N belonging to the calling process. Note that this driver * consists of only the ``open()'' routine, because all subsequent * references to this file will be direct to the other driver. * * XXX: we could give this one a cloning event handler if necessary. */ /* ARGSUSED */ static int fdopen(struct cdev *dev, int mode, int type, struct thread *td) { /* * XXX Kludge: set curthread->td_dupfd to contain the value of the * the file descriptor being sought for duplication. The error * return ensures that the vnode for this device will be released * by vn_open. Open will detect this special error and take the * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN * will simply report the error. */ td->td_dupfd = dev2unit(dev); return (ENODEV); } static struct cdevsw fildesc_cdevsw = { .d_version = D_VERSION, .d_open = fdopen, .d_name = "FD", }; static void fildesc_drvinit(void *unused) { struct cdev *dev; dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/0"); make_dev_alias(dev, "stdin"); dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/1"); make_dev_alias(dev, "stdout"); dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/2"); make_dev_alias(dev, "stderr"); } SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c index 8ff78b9d6319..e8d6df5c4193 100644 --- a/sys/kern/vfs_vnops.c +++ b/sys/kern/vfs_vnops.c @@ -1,3571 +1,3571 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Copyright (c) 2012 Konstantin Belousov * Copyright (c) 2013, 2014 The FreeBSD Foundation * * Portions of this software were developed by Konstantin Belousov * under sponsorship from the FreeBSD Foundation. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_hwpmc_hooks.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HWPMC_HOOKS #include #endif static fo_rdwr_t vn_read; static fo_rdwr_t vn_write; static fo_rdwr_t vn_io_fault; static fo_truncate_t vn_truncate; static fo_ioctl_t vn_ioctl; static fo_poll_t vn_poll; static fo_kqfilter_t vn_kqfilter; static fo_close_t vn_closefile; static fo_mmap_t vn_mmap; static fo_fallocate_t vn_fallocate; struct fileops vnops = { .fo_read = vn_io_fault, .fo_write = vn_io_fault, .fo_truncate = vn_truncate, .fo_ioctl = vn_ioctl, .fo_poll = vn_poll, .fo_kqfilter = vn_kqfilter, .fo_stat = vn_statfile, .fo_close = vn_closefile, .fo_chmod = vn_chmod, .fo_chown = vn_chown, .fo_sendfile = vn_sendfile, .fo_seek = vn_seek, .fo_fill_kinfo = vn_fill_kinfo, .fo_mmap = vn_mmap, .fo_fallocate = vn_fallocate, .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE }; const u_int io_hold_cnt = 16; static int vn_io_fault_enable = 1; SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RWTUN, &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); static int vn_io_fault_prefault = 0; SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RWTUN, &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting"); static int vn_io_pgcache_read_enable = 1; SYSCTL_INT(_debug, OID_AUTO, vn_io_pgcache_read_enable, CTLFLAG_RWTUN, &vn_io_pgcache_read_enable, 0, "Enable copying from page cache for reads, avoiding fs"); static u_long vn_io_faults_cnt; SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); static int vfs_allow_read_dir = 0; SYSCTL_INT(_security_bsd, OID_AUTO, allow_read_dir, CTLFLAG_RW, &vfs_allow_read_dir, 0, "Enable read(2) of directory by root for filesystems that support it"); /* * Returns true if vn_io_fault mode of handling the i/o request should * be used. */ static bool do_vn_io_fault(struct vnode *vp, struct uio *uio) { struct mount *mp; return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && (mp = vp->v_mount) != NULL && (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); } /* * Structure used to pass arguments to vn_io_fault1(), to do either * file- or vnode-based I/O calls. */ struct vn_io_fault_args { enum { VN_IO_FAULT_FOP, VN_IO_FAULT_VOP } kind; struct ucred *cred; int flags; union { struct fop_args_tag { struct file *fp; fo_rdwr_t *doio; } fop_args; struct vop_args_tag { struct vnode *vp; } vop_args; } args; }; static int vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, struct thread *td); int vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp) { struct thread *td = ndp->ni_cnd.cn_thread; return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); } static uint64_t open2nameif(int fmode, u_int vn_open_flags) { uint64_t res; res = ISOPEN | LOCKLEAF; if ((fmode & O_RESOLVE_BENEATH) != 0) res |= RBENEATH; if ((fmode & O_EMPTY_PATH) != 0) res |= EMPTYPATH; if ((vn_open_flags & VN_OPEN_NOAUDIT) == 0) res |= AUDITVNODE1; if ((vn_open_flags & VN_OPEN_NOCAPCHECK) != 0) res |= NOCAPCHECK; return (res); } /* * Common code for vnode open operations via a name lookup. * Lookup the vnode and invoke VOP_CREATE if needed. * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. * * Note that this does NOT free nameidata for the successful case, * due to the NDINIT being done elsewhere. */ int vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, struct ucred *cred, struct file *fp) { struct vnode *vp; struct mount *mp; struct thread *td = ndp->ni_cnd.cn_thread; struct vattr vat; struct vattr *vap = &vat; int fmode, error; bool first_open; restart: first_open = false; fmode = *flagp; if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT | O_EXCL | O_DIRECTORY) || (fmode & (O_CREAT | O_EMPTY_PATH)) == (O_CREAT | O_EMPTY_PATH)) return (EINVAL); else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) { ndp->ni_cnd.cn_nameiop = CREATE; ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags); /* * Set NOCACHE to avoid flushing the cache when * rolling in many files at once. * * Set NC_KEEPPOSENTRY to keep positive entries if they already * exist despite NOCACHE. */ ndp->ni_cnd.cn_flags |= LOCKPARENT | NOCACHE | NC_KEEPPOSENTRY; if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) ndp->ni_cnd.cn_flags |= FOLLOW; if ((vn_open_flags & VN_OPEN_INVFS) == 0) bwillwrite(); if ((error = namei(ndp)) != 0) return (error); if (ndp->ni_vp == NULL) { VATTR_NULL(vap); vap->va_type = VREG; vap->va_mode = cmode; if (fmode & O_EXCL) vap->va_vaflags |= VA_EXCLUSIVE; if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { NDFREE(ndp, NDF_ONLY_PNBUF); vput(ndp->ni_dvp); if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) return (error); NDREINIT(ndp); goto restart; } if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) ndp->ni_cnd.cn_flags |= MAKEENTRY; #ifdef MAC error = mac_vnode_check_create(cred, ndp->ni_dvp, &ndp->ni_cnd, vap); if (error == 0) #endif error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, &ndp->ni_cnd, vap); vp = ndp->ni_vp; if (error == 0 && (fmode & O_EXCL) != 0 && (fmode & (O_EXLOCK | O_SHLOCK)) != 0) { VI_LOCK(vp); vp->v_iflag |= VI_FOPENING; VI_UNLOCK(vp); first_open = true; } VOP_VPUT_PAIR(ndp->ni_dvp, error == 0 ? &vp : NULL, false); vn_finished_write(mp); if (error) { NDFREE(ndp, NDF_ONLY_PNBUF); if (error == ERELOOKUP) { NDREINIT(ndp); goto restart; } return (error); } fmode &= ~O_TRUNC; } else { if (ndp->ni_dvp == ndp->ni_vp) vrele(ndp->ni_dvp); else vput(ndp->ni_dvp); ndp->ni_dvp = NULL; vp = ndp->ni_vp; if (fmode & O_EXCL) { error = EEXIST; goto bad; } if (vp->v_type == VDIR) { error = EISDIR; goto bad; } fmode &= ~O_CREAT; } } else { ndp->ni_cnd.cn_nameiop = LOOKUP; ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags); ndp->ni_cnd.cn_flags |= (fmode & O_NOFOLLOW) != 0 ? NOFOLLOW : FOLLOW; if ((fmode & FWRITE) == 0) ndp->ni_cnd.cn_flags |= LOCKSHARED; if ((error = namei(ndp)) != 0) return (error); vp = ndp->ni_vp; } error = vn_open_vnode(vp, fmode, cred, td, fp); if (first_open) { VI_LOCK(vp); vp->v_iflag &= ~VI_FOPENING; wakeup(vp); VI_UNLOCK(vp); } if (error) goto bad; *flagp = fmode; return (0); bad: NDFREE(ndp, NDF_ONLY_PNBUF); vput(vp); *flagp = fmode; ndp->ni_vp = NULL; return (error); } static int vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp) { struct flock lf; int error, lock_flags, type; ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock"); if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0) return (0); KASSERT(fp != NULL, ("open with flock requires fp")); if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE) return (EOPNOTSUPP); lock_flags = VOP_ISLOCKED(vp); VOP_UNLOCK(vp); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK; type = F_FLOCK; if ((fmode & FNONBLOCK) == 0) type |= F_WAIT; if ((fmode & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) type |= F_FIRSTOPEN; error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); if (error == 0) fp->f_flag |= FHASLOCK; vn_lock(vp, lock_flags | LK_RETRY); return (error); } /* * Common code for vnode open operations once a vnode is located. * Check permissions, and call the VOP_OPEN routine. */ int vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, struct thread *td, struct file *fp) { accmode_t accmode; int error; if (vp->v_type == VLNK) { if ((fmode & O_PATH) == 0 || (fmode & FEXEC) != 0) return (EMLINK); } if (vp->v_type == VSOCK) return (EOPNOTSUPP); if (vp->v_type != VDIR && fmode & O_DIRECTORY) return (ENOTDIR); accmode = 0; if ((fmode & O_PATH) == 0) { if ((fmode & (FWRITE | O_TRUNC)) != 0) { if (vp->v_type == VDIR) return (EISDIR); accmode |= VWRITE; } if ((fmode & FREAD) != 0) accmode |= VREAD; if ((fmode & O_APPEND) && (fmode & FWRITE)) accmode |= VAPPEND; #ifdef MAC if ((fmode & O_CREAT) != 0) accmode |= VCREAT; #endif } if ((fmode & FEXEC) != 0) accmode |= VEXEC; #ifdef MAC if ((fmode & O_VERIFY) != 0) accmode |= VVERIFY; error = mac_vnode_check_open(cred, vp, accmode); if (error != 0) return (error); accmode &= ~(VCREAT | VVERIFY); #endif if ((fmode & O_CREAT) == 0 && accmode != 0) { error = VOP_ACCESS(vp, accmode, cred, td); if (error != 0) return (error); } if ((fmode & O_PATH) != 0) { if (vp->v_type == VFIFO) error = EPIPE; else error = VOP_ACCESS(vp, VREAD, cred, td); if (error == 0) fp->f_flag |= FKQALLOWED; return (0); } if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) vn_lock(vp, LK_UPGRADE | LK_RETRY); error = VOP_OPEN(vp, fmode, cred, td, fp); if (error != 0) return (error); error = vn_open_vnode_advlock(vp, fmode, fp); if (error == 0 && (fmode & FWRITE) != 0) { error = VOP_ADD_WRITECOUNT(vp, 1); if (error == 0) { CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", __func__, vp, vp->v_writecount); } } /* * Error from advlock or VOP_ADD_WRITECOUNT() still requires * calling VOP_CLOSE() to pair with earlier VOP_OPEN(). */ if (error != 0) { if (fp != NULL) { /* * Arrange the call by having fdrop() to use * vn_closefile(). This is to satisfy * filesystems like devfs or tmpfs, which * override fo_close(). */ fp->f_flag |= FOPENFAILED; fp->f_vnode = vp; if (fp->f_ops == &badfileops) { fp->f_type = DTYPE_VNODE; fp->f_ops = &vnops; } vref(vp); } else { /* * If there is no fp, due to kernel-mode open, * we can call VOP_CLOSE() now. */ if (vp->v_type != VFIFO && (fmode & FWRITE) != 0 && !MNT_EXTENDED_SHARED(vp->v_mount) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) vn_lock(vp, LK_UPGRADE | LK_RETRY); (void)VOP_CLOSE(vp, fmode & (FREAD | FWRITE | FEXEC), cred, td); } } ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); return (error); } /* * Check for write permissions on the specified vnode. * Prototype text segments cannot be written. * It is racy. */ int vn_writechk(struct vnode *vp) { ASSERT_VOP_LOCKED(vp, "vn_writechk"); /* * If there's shared text associated with * the vnode, try to free it up once. If * we fail, we can't allow writing. */ if (VOP_IS_TEXT(vp)) return (ETXTBSY); return (0); } /* * Vnode close call */ static int vn_close1(struct vnode *vp, int flags, struct ucred *file_cred, struct thread *td, bool keep_ref) { struct mount *mp; int error, lock_flags; if (vp->v_type != VFIFO && (flags & FWRITE) == 0 && MNT_EXTENDED_SHARED(vp->v_mount)) lock_flags = LK_SHARED; else lock_flags = LK_EXCLUSIVE; vn_start_write(vp, &mp, V_WAIT); vn_lock(vp, lock_flags | LK_RETRY); AUDIT_ARG_VNODE1(vp); if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) { VOP_ADD_WRITECOUNT_CHECKED(vp, -1); CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", __func__, vp, vp->v_writecount); } error = VOP_CLOSE(vp, flags, file_cred, td); if (keep_ref) VOP_UNLOCK(vp); else vput(vp); vn_finished_write(mp); return (error); } int vn_close(struct vnode *vp, int flags, struct ucred *file_cred, struct thread *td) { return (vn_close1(vp, flags, file_cred, td, false)); } /* * Heuristic to detect sequential operation. */ static int sequential_heuristic(struct uio *uio, struct file *fp) { enum uio_rw rw; ASSERT_VOP_LOCKED(fp->f_vnode, __func__); rw = uio->uio_rw; if (fp->f_flag & FRDAHEAD) return (fp->f_seqcount[rw] << IO_SEQSHIFT); /* * Offset 0 is handled specially. open() sets f_seqcount to 1 so * that the first I/O is normally considered to be slightly * sequential. Seeking to offset 0 doesn't change sequentiality * unless previous seeks have reduced f_seqcount to 0, in which * case offset 0 is not special. */ if ((uio->uio_offset == 0 && fp->f_seqcount[rw] > 0) || uio->uio_offset == fp->f_nextoff[rw]) { /* * f_seqcount is in units of fixed-size blocks so that it * depends mainly on the amount of sequential I/O and not * much on the number of sequential I/O's. The fixed size * of 16384 is hard-coded here since it is (not quite) just * a magic size that works well here. This size is more * closely related to the best I/O size for real disks than * to any block size used by software. */ if (uio->uio_resid >= IO_SEQMAX * 16384) fp->f_seqcount[rw] = IO_SEQMAX; else { fp->f_seqcount[rw] += howmany(uio->uio_resid, 16384); if (fp->f_seqcount[rw] > IO_SEQMAX) fp->f_seqcount[rw] = IO_SEQMAX; } return (fp->f_seqcount[rw] << IO_SEQSHIFT); } /* Not sequential. Quickly draw-down sequentiality. */ if (fp->f_seqcount[rw] > 1) fp->f_seqcount[rw] = 1; else fp->f_seqcount[rw] = 0; return (0); } /* * Package up an I/O request on a vnode into a uio and do it. */ int vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred, struct ucred *file_cred, ssize_t *aresid, struct thread *td) { struct uio auio; struct iovec aiov; struct mount *mp; struct ucred *cred; void *rl_cookie; struct vn_io_fault_args args; int error, lock_flags; if (offset < 0 && vp->v_type != VCHR) return (EINVAL); auio.uio_iov = &aiov; auio.uio_iovcnt = 1; aiov.iov_base = base; aiov.iov_len = len; auio.uio_resid = len; auio.uio_offset = offset; auio.uio_segflg = segflg; auio.uio_rw = rw; auio.uio_td = td; error = 0; if ((ioflg & IO_NODELOCKED) == 0) { if ((ioflg & IO_RANGELOCKED) == 0) { if (rw == UIO_READ) { rl_cookie = vn_rangelock_rlock(vp, offset, offset + len); } else if ((ioflg & IO_APPEND) != 0) { rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); } else { rl_cookie = vn_rangelock_wlock(vp, offset, offset + len); } } else rl_cookie = NULL; mp = NULL; if (rw == UIO_WRITE) { if (vp->v_type != VCHR && (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) goto out; lock_flags = vn_lktype_write(mp, vp); } else lock_flags = LK_SHARED; vn_lock(vp, lock_flags | LK_RETRY); } else rl_cookie = NULL; ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); #ifdef MAC if ((ioflg & IO_NOMACCHECK) == 0) { if (rw == UIO_READ) error = mac_vnode_check_read(active_cred, file_cred, vp); else error = mac_vnode_check_write(active_cred, file_cred, vp); } #endif if (error == 0) { if (file_cred != NULL) cred = file_cred; else cred = active_cred; if (do_vn_io_fault(vp, &auio)) { args.kind = VN_IO_FAULT_VOP; args.cred = cred; args.flags = ioflg; args.args.vop_args.vp = vp; error = vn_io_fault1(vp, &auio, &args, td); } else if (rw == UIO_READ) { error = VOP_READ(vp, &auio, ioflg, cred); } else /* if (rw == UIO_WRITE) */ { error = VOP_WRITE(vp, &auio, ioflg, cred); } } if (aresid) *aresid = auio.uio_resid; else if (auio.uio_resid && error == 0) error = EIO; if ((ioflg & IO_NODELOCKED) == 0) { VOP_UNLOCK(vp); if (mp != NULL) vn_finished_write(mp); } out: if (rl_cookie != NULL) vn_rangelock_unlock(vp, rl_cookie); return (error); } /* * Package up an I/O request on a vnode into a uio and do it. The I/O * request is split up into smaller chunks and we try to avoid saturating * the buffer cache while potentially holding a vnode locked, so we * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() * to give other processes a chance to lock the vnode (either other processes * core'ing the same binary, or unrelated processes scanning the directory). */ int vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len, off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred, struct ucred *file_cred, size_t *aresid, struct thread *td) { int error = 0; ssize_t iaresid; do { int chunk; /* * Force `offset' to a multiple of MAXBSIZE except possibly * for the first chunk, so that filesystems only need to * write full blocks except possibly for the first and last * chunks. */ chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; if (chunk > len) chunk = len; if (rw != UIO_READ && vp->v_type == VREG) bwillwrite(); iaresid = 0; error = vn_rdwr(rw, vp, base, chunk, offset, segflg, ioflg, active_cred, file_cred, &iaresid, td); len -= chunk; /* aresid calc already includes length */ if (error) break; offset += chunk; base = (char *)base + chunk; kern_yield(PRI_USER); } while (len); if (aresid) *aresid = len + iaresid; return (error); } #if OFF_MAX <= LONG_MAX off_t foffset_lock(struct file *fp, int flags) { volatile short *flagsp; off_t res; short state; KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); if ((flags & FOF_NOLOCK) != 0) return (atomic_load_long(&fp->f_offset)); /* * According to McKusick the vn lock was protecting f_offset here. * It is now protected by the FOFFSET_LOCKED flag. */ flagsp = &fp->f_vnread_flags; if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED)) return (atomic_load_long(&fp->f_offset)); sleepq_lock(&fp->f_vnread_flags); state = atomic_load_16(flagsp); for (;;) { if ((state & FOFFSET_LOCKED) == 0) { if (!atomic_fcmpset_acq_16(flagsp, &state, FOFFSET_LOCKED)) continue; break; } if ((state & FOFFSET_LOCK_WAITING) == 0) { if (!atomic_fcmpset_acq_16(flagsp, &state, state | FOFFSET_LOCK_WAITING)) continue; } DROP_GIANT(); sleepq_add(&fp->f_vnread_flags, NULL, "vofflock", 0, 0); sleepq_wait(&fp->f_vnread_flags, PUSER -1); PICKUP_GIANT(); sleepq_lock(&fp->f_vnread_flags); state = atomic_load_16(flagsp); } res = atomic_load_long(&fp->f_offset); sleepq_release(&fp->f_vnread_flags); return (res); } void foffset_unlock(struct file *fp, off_t val, int flags) { volatile short *flagsp; short state; KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); if ((flags & FOF_NOUPDATE) == 0) atomic_store_long(&fp->f_offset, val); if ((flags & FOF_NEXTOFF_R) != 0) fp->f_nextoff[UIO_READ] = val; if ((flags & FOF_NEXTOFF_W) != 0) fp->f_nextoff[UIO_WRITE] = val; if ((flags & FOF_NOLOCK) != 0) return; flagsp = &fp->f_vnread_flags; state = atomic_load_16(flagsp); if ((state & FOFFSET_LOCK_WAITING) == 0 && atomic_cmpset_rel_16(flagsp, state, 0)) return; sleepq_lock(&fp->f_vnread_flags); MPASS((fp->f_vnread_flags & FOFFSET_LOCKED) != 0); MPASS((fp->f_vnread_flags & FOFFSET_LOCK_WAITING) != 0); fp->f_vnread_flags = 0; sleepq_broadcast(&fp->f_vnread_flags, SLEEPQ_SLEEP, 0, 0); sleepq_release(&fp->f_vnread_flags); } #else off_t foffset_lock(struct file *fp, int flags) { struct mtx *mtxp; off_t res; KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); mtxp = mtx_pool_find(mtxpool_sleep, fp); mtx_lock(mtxp); if ((flags & FOF_NOLOCK) == 0) { while (fp->f_vnread_flags & FOFFSET_LOCKED) { fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; msleep(&fp->f_vnread_flags, mtxp, PUSER -1, "vofflock", 0); } fp->f_vnread_flags |= FOFFSET_LOCKED; } res = fp->f_offset; mtx_unlock(mtxp); return (res); } void foffset_unlock(struct file *fp, off_t val, int flags) { struct mtx *mtxp; KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); mtxp = mtx_pool_find(mtxpool_sleep, fp); mtx_lock(mtxp); if ((flags & FOF_NOUPDATE) == 0) fp->f_offset = val; if ((flags & FOF_NEXTOFF_R) != 0) fp->f_nextoff[UIO_READ] = val; if ((flags & FOF_NEXTOFF_W) != 0) fp->f_nextoff[UIO_WRITE] = val; if ((flags & FOF_NOLOCK) == 0) { KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, ("Lost FOFFSET_LOCKED")); if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) wakeup(&fp->f_vnread_flags); fp->f_vnread_flags = 0; } mtx_unlock(mtxp); } #endif void foffset_lock_uio(struct file *fp, struct uio *uio, int flags) { if ((flags & FOF_OFFSET) == 0) uio->uio_offset = foffset_lock(fp, flags); } void foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) { if ((flags & FOF_OFFSET) == 0) foffset_unlock(fp, uio->uio_offset, flags); } static int get_advice(struct file *fp, struct uio *uio) { struct mtx *mtxp; int ret; ret = POSIX_FADV_NORMAL; if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG) return (ret); mtxp = mtx_pool_find(mtxpool_sleep, fp); mtx_lock(mtxp); if (fp->f_advice != NULL && uio->uio_offset >= fp->f_advice->fa_start && uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) ret = fp->f_advice->fa_advice; mtx_unlock(mtxp); return (ret); } static int get_write_ioflag(struct file *fp) { int ioflag; struct mount *mp; struct vnode *vp; ioflag = 0; vp = fp->f_vnode; mp = atomic_load_ptr(&vp->v_mount); if ((fp->f_flag & O_DIRECT) != 0) ioflag |= IO_DIRECT; if ((fp->f_flag & O_FSYNC) != 0 || (mp != NULL && (mp->mnt_flag & MNT_SYNCHRONOUS) != 0)) ioflag |= IO_SYNC; /* * For O_DSYNC we set both IO_SYNC and IO_DATASYNC, so that VOP_WRITE() * or VOP_DEALLOCATE() implementations that don't understand IO_DATASYNC * fall back to full O_SYNC behavior. */ if ((fp->f_flag & O_DSYNC) != 0) ioflag |= IO_SYNC | IO_DATASYNC; return (ioflag); } int vn_read_from_obj(struct vnode *vp, struct uio *uio) { vm_object_t obj; vm_page_t ma[io_hold_cnt + 2]; off_t off, vsz; ssize_t resid; int error, i, j; MPASS(uio->uio_resid <= ptoa(io_hold_cnt + 2)); obj = atomic_load_ptr(&vp->v_object); if (obj == NULL) return (EJUSTRETURN); /* * Depends on type stability of vm_objects. */ vm_object_pip_add(obj, 1); if ((obj->flags & OBJ_DEAD) != 0) { /* * Note that object might be already reused from the * vnode, and the OBJ_DEAD flag cleared. This is fine, * we recheck for DOOMED vnode state after all pages * are busied, and retract then. * * But we check for OBJ_DEAD to ensure that we do not * busy pages while vm_object_terminate_pages() * processes the queue. */ error = EJUSTRETURN; goto out_pip; } resid = uio->uio_resid; off = uio->uio_offset; for (i = 0; resid > 0; i++) { MPASS(i < io_hold_cnt + 2); ma[i] = vm_page_grab_unlocked(obj, atop(off), VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY | VM_ALLOC_NOWAIT); if (ma[i] == NULL) break; /* * Skip invalid pages. Valid mask can be partial only * at EOF, and we clip later. */ if (vm_page_none_valid(ma[i])) { vm_page_sunbusy(ma[i]); break; } resid -= PAGE_SIZE; off += PAGE_SIZE; } if (i == 0) { error = EJUSTRETURN; goto out_pip; } /* * Check VIRF_DOOMED after we busied our pages. Since * vgonel() terminates the vnode' vm_object, it cannot * process past pages busied by us. */ if (VN_IS_DOOMED(vp)) { error = EJUSTRETURN; goto out; } resid = PAGE_SIZE - (uio->uio_offset & PAGE_MASK) + ptoa(i - 1); if (resid > uio->uio_resid) resid = uio->uio_resid; /* * Unlocked read of vnp_size is safe because truncation cannot * pass busied page. But we load vnp_size into a local * variable so that possible concurrent extension does not * break calculation. */ #if defined(__powerpc__) && !defined(__powerpc64__) vsz = obj->un_pager.vnp.vnp_size; #else vsz = atomic_load_64(&obj->un_pager.vnp.vnp_size); #endif if (uio->uio_offset >= vsz) { error = EJUSTRETURN; goto out; } if (uio->uio_offset + resid > vsz) resid = vsz - uio->uio_offset; error = vn_io_fault_pgmove(ma, uio->uio_offset & PAGE_MASK, resid, uio); out: for (j = 0; j < i; j++) { if (error == 0) vm_page_reference(ma[j]); vm_page_sunbusy(ma[j]); } out_pip: vm_object_pip_wakeup(obj); if (error != 0) return (error); return (uio->uio_resid == 0 ? 0 : EJUSTRETURN); } /* * File table vnode read routine. */ static int vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { struct vnode *vp; off_t orig_offset; int error, ioflag; int advice; KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td)); KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); vp = fp->f_vnode; ioflag = 0; if (fp->f_flag & FNONBLOCK) ioflag |= IO_NDELAY; if (fp->f_flag & O_DIRECT) ioflag |= IO_DIRECT; /* * Try to read from page cache. VIRF_DOOMED check is racy but * allows us to avoid unneeded work outright. */ if (vn_io_pgcache_read_enable && !mac_vnode_check_read_enabled() && (vn_irflag_read(vp) & (VIRF_DOOMED | VIRF_PGREAD)) == VIRF_PGREAD) { error = VOP_READ_PGCACHE(vp, uio, ioflag, fp->f_cred); if (error == 0) { fp->f_nextoff[UIO_READ] = uio->uio_offset; return (0); } if (error != EJUSTRETURN) return (error); } advice = get_advice(fp, uio); vn_lock(vp, LK_SHARED | LK_RETRY); switch (advice) { case POSIX_FADV_NORMAL: case POSIX_FADV_SEQUENTIAL: case POSIX_FADV_NOREUSE: ioflag |= sequential_heuristic(uio, fp); break; case POSIX_FADV_RANDOM: /* Disable read-ahead for random I/O. */ break; } orig_offset = uio->uio_offset; #ifdef MAC error = mac_vnode_check_read(active_cred, fp->f_cred, vp); if (error == 0) #endif error = VOP_READ(vp, uio, ioflag, fp->f_cred); fp->f_nextoff[UIO_READ] = uio->uio_offset; VOP_UNLOCK(vp); if (error == 0 && advice == POSIX_FADV_NOREUSE && orig_offset != uio->uio_offset) /* * Use POSIX_FADV_DONTNEED to flush pages and buffers * for the backing file after a POSIX_FADV_NOREUSE * read(2). */ error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, POSIX_FADV_DONTNEED); return (error); } /* * File table vnode write routine. */ static int vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { struct vnode *vp; struct mount *mp; off_t orig_offset; int error, ioflag; int advice; bool need_finished_write; KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td)); KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); vp = fp->f_vnode; if (vp->v_type == VREG) bwillwrite(); ioflag = IO_UNIT; if (vp->v_type == VREG && (fp->f_flag & O_APPEND) != 0) ioflag |= IO_APPEND; if ((fp->f_flag & FNONBLOCK) != 0) ioflag |= IO_NDELAY; ioflag |= get_write_ioflag(fp); mp = NULL; need_finished_write = false; if (vp->v_type != VCHR) { error = vn_start_write(vp, &mp, V_WAIT | PCATCH); if (error != 0) goto unlock; need_finished_write = true; } advice = get_advice(fp, uio); vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY); switch (advice) { case POSIX_FADV_NORMAL: case POSIX_FADV_SEQUENTIAL: case POSIX_FADV_NOREUSE: ioflag |= sequential_heuristic(uio, fp); break; case POSIX_FADV_RANDOM: /* XXX: Is this correct? */ break; } orig_offset = uio->uio_offset; #ifdef MAC error = mac_vnode_check_write(active_cred, fp->f_cred, vp); if (error == 0) #endif error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); fp->f_nextoff[UIO_WRITE] = uio->uio_offset; VOP_UNLOCK(vp); if (need_finished_write) vn_finished_write(mp); if (error == 0 && advice == POSIX_FADV_NOREUSE && orig_offset != uio->uio_offset) /* * Use POSIX_FADV_DONTNEED to flush pages and buffers * for the backing file after a POSIX_FADV_NOREUSE * write(2). */ error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, POSIX_FADV_DONTNEED); unlock: return (error); } /* * The vn_io_fault() is a wrapper around vn_read() and vn_write() to * prevent the following deadlock: * * Assume that the thread A reads from the vnode vp1 into userspace * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is * currently not resident, then system ends up with the call chain * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) * which establishes lock order vp1->vn_lock, then vp2->vn_lock. * If, at the same time, thread B reads from vnode vp2 into buffer buf2 * backed by the pages of vnode vp1, and some page in buf2 is not * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. * * To prevent the lock order reversal and deadlock, vn_io_fault() does * not allow page faults to happen during VOP_READ() or VOP_WRITE(). * Instead, it first tries to do the whole range i/o with pagefaults * disabled. If all pages in the i/o buffer are resident and mapped, * VOP will succeed (ignoring the genuine filesystem errors). * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do * i/o in chunks, with all pages in the chunk prefaulted and held * using vm_fault_quick_hold_pages(). * * Filesystems using this deadlock avoidance scheme should use the * array of the held pages from uio, saved in the curthread->td_ma, * instead of doing uiomove(). A helper function * vn_io_fault_uiomove() converts uiomove request into * uiomove_fromphys() over td_ma array. * * Since vnode locks do not cover the whole i/o anymore, rangelocks * make the current i/o request atomic with respect to other i/os and * truncations. */ /* * Decode vn_io_fault_args and perform the corresponding i/o. */ static int vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, struct thread *td) { int error, save; error = 0; save = vm_fault_disable_pagefaults(); switch (args->kind) { case VN_IO_FAULT_FOP: error = (args->args.fop_args.doio)(args->args.fop_args.fp, uio, args->cred, args->flags, td); break; case VN_IO_FAULT_VOP: if (uio->uio_rw == UIO_READ) { error = VOP_READ(args->args.vop_args.vp, uio, args->flags, args->cred); } else if (uio->uio_rw == UIO_WRITE) { error = VOP_WRITE(args->args.vop_args.vp, uio, args->flags, args->cred); } break; default: panic("vn_io_fault_doio: unknown kind of io %d %d", args->kind, uio->uio_rw); } vm_fault_enable_pagefaults(save); return (error); } static int vn_io_fault_touch(char *base, const struct uio *uio) { int r; r = fubyte(base); if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) return (EFAULT); return (0); } static int vn_io_fault_prefault_user(const struct uio *uio) { char *base; const struct iovec *iov; size_t len; ssize_t resid; int error, i; KASSERT(uio->uio_segflg == UIO_USERSPACE, ("vn_io_fault_prefault userspace")); error = i = 0; iov = uio->uio_iov; resid = uio->uio_resid; base = iov->iov_base; len = iov->iov_len; while (resid > 0) { error = vn_io_fault_touch(base, uio); if (error != 0) break; if (len < PAGE_SIZE) { if (len != 0) { error = vn_io_fault_touch(base + len - 1, uio); if (error != 0) break; resid -= len; } if (++i >= uio->uio_iovcnt) break; iov = uio->uio_iov + i; base = iov->iov_base; len = iov->iov_len; } else { len -= PAGE_SIZE; base += PAGE_SIZE; resid -= PAGE_SIZE; } } return (error); } /* * Common code for vn_io_fault(), agnostic to the kind of i/o request. * Uses vn_io_fault_doio() to make the call to an actual i/o function. * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request * into args and call vn_io_fault1() to handle faults during the user * mode buffer accesses. */ static int vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, struct thread *td) { vm_page_t ma[io_hold_cnt + 2]; struct uio *uio_clone, short_uio; struct iovec short_iovec[1]; vm_page_t *prev_td_ma; vm_prot_t prot; vm_offset_t addr, end; size_t len, resid; ssize_t adv; int error, cnt, saveheld, prev_td_ma_cnt; if (vn_io_fault_prefault) { error = vn_io_fault_prefault_user(uio); if (error != 0) return (error); /* Or ignore ? */ } prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; /* * The UFS follows IO_UNIT directive and replays back both * uio_offset and uio_resid if an error is encountered during the * operation. But, since the iovec may be already advanced, * uio is still in an inconsistent state. * * Cache a copy of the original uio, which is advanced to the redo * point using UIO_NOCOPY below. */ uio_clone = cloneuio(uio); resid = uio->uio_resid; short_uio.uio_segflg = UIO_USERSPACE; short_uio.uio_rw = uio->uio_rw; short_uio.uio_td = uio->uio_td; error = vn_io_fault_doio(args, uio, td); if (error != EFAULT) goto out; atomic_add_long(&vn_io_faults_cnt, 1); uio_clone->uio_segflg = UIO_NOCOPY; uiomove(NULL, resid - uio->uio_resid, uio_clone); uio_clone->uio_segflg = uio->uio_segflg; saveheld = curthread_pflags_set(TDP_UIOHELD); prev_td_ma = td->td_ma; prev_td_ma_cnt = td->td_ma_cnt; while (uio_clone->uio_resid != 0) { len = uio_clone->uio_iov->iov_len; if (len == 0) { KASSERT(uio_clone->uio_iovcnt >= 1, ("iovcnt underflow")); uio_clone->uio_iov++; uio_clone->uio_iovcnt--; continue; } if (len > ptoa(io_hold_cnt)) len = ptoa(io_hold_cnt); addr = (uintptr_t)uio_clone->uio_iov->iov_base; end = round_page(addr + len); if (end < addr) { error = EFAULT; break; } cnt = atop(end - trunc_page(addr)); /* * A perfectly misaligned address and length could cause * both the start and the end of the chunk to use partial * page. +2 accounts for such a situation. */ cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, addr, len, prot, ma, io_hold_cnt + 2); if (cnt == -1) { error = EFAULT; break; } short_uio.uio_iov = &short_iovec[0]; short_iovec[0].iov_base = (void *)addr; short_uio.uio_iovcnt = 1; short_uio.uio_resid = short_iovec[0].iov_len = len; short_uio.uio_offset = uio_clone->uio_offset; td->td_ma = ma; td->td_ma_cnt = cnt; error = vn_io_fault_doio(args, &short_uio, td); vm_page_unhold_pages(ma, cnt); adv = len - short_uio.uio_resid; uio_clone->uio_iov->iov_base = (char *)uio_clone->uio_iov->iov_base + adv; uio_clone->uio_iov->iov_len -= adv; uio_clone->uio_resid -= adv; uio_clone->uio_offset += adv; uio->uio_resid -= adv; uio->uio_offset += adv; if (error != 0 || adv == 0) break; } td->td_ma = prev_td_ma; td->td_ma_cnt = prev_td_ma_cnt; curthread_pflags_restore(saveheld); out: free(uio_clone, M_IOV); return (error); } static int vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { fo_rdwr_t *doio; struct vnode *vp; void *rl_cookie; struct vn_io_fault_args args; int error; doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; vp = fp->f_vnode; /* * The ability to read(2) on a directory has historically been * allowed for all users, but this can and has been the source of * at least one security issue in the past. As such, it is now hidden * away behind a sysctl for those that actually need it to use it, and * restricted to root when it's turned on to make it relatively safe to * leave on for longer sessions of need. */ if (vp->v_type == VDIR) { KASSERT(uio->uio_rw == UIO_READ, ("illegal write attempted on a directory")); if (!vfs_allow_read_dir) return (EISDIR); if ((error = priv_check(td, PRIV_VFS_READ_DIR)) != 0) return (EISDIR); } foffset_lock_uio(fp, uio, flags); if (do_vn_io_fault(vp, uio)) { args.kind = VN_IO_FAULT_FOP; args.args.fop_args.fp = fp; args.args.fop_args.doio = doio; args.cred = active_cred; args.flags = flags | FOF_OFFSET; if (uio->uio_rw == UIO_READ) { rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, uio->uio_offset + uio->uio_resid); } else if ((fp->f_flag & O_APPEND) != 0 || (flags & FOF_OFFSET) == 0) { /* For appenders, punt and lock the whole range. */ rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); } else { rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, uio->uio_offset + uio->uio_resid); } error = vn_io_fault1(vp, uio, &args, td); vn_rangelock_unlock(vp, rl_cookie); } else { error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); } foffset_unlock_uio(fp, uio, flags); return (error); } /* * Helper function to perform the requested uiomove operation using * the held pages for io->uio_iov[0].iov_base buffer instead of * copyin/copyout. Access to the pages with uiomove_fromphys() * instead of iov_base prevents page faults that could occur due to * pmap_collect() invalidating the mapping created by * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or * object cleanup revoking the write access from page mappings. * * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() * instead of plain uiomove(). */ int vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) { struct uio transp_uio; struct iovec transp_iov[1]; struct thread *td; size_t adv; int error, pgadv; td = curthread; if ((td->td_pflags & TDP_UIOHELD) == 0 || uio->uio_segflg != UIO_USERSPACE) return (uiomove(data, xfersize, uio)); KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); transp_iov[0].iov_base = data; transp_uio.uio_iov = &transp_iov[0]; transp_uio.uio_iovcnt = 1; if (xfersize > uio->uio_resid) xfersize = uio->uio_resid; transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; transp_uio.uio_offset = 0; transp_uio.uio_segflg = UIO_SYSSPACE; /* * Since transp_iov points to data, and td_ma page array * corresponds to original uio->uio_iov, we need to invert the * direction of the i/o operation as passed to * uiomove_fromphys(). */ switch (uio->uio_rw) { case UIO_WRITE: transp_uio.uio_rw = UIO_READ; break; case UIO_READ: transp_uio.uio_rw = UIO_WRITE; break; } transp_uio.uio_td = uio->uio_td; error = uiomove_fromphys(td->td_ma, ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, xfersize, &transp_uio); adv = xfersize - transp_uio.uio_resid; pgadv = (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); td->td_ma += pgadv; KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, pgadv)); td->td_ma_cnt -= pgadv; uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; uio->uio_iov->iov_len -= adv; uio->uio_resid -= adv; uio->uio_offset += adv; return (error); } int vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, struct uio *uio) { struct thread *td; vm_offset_t iov_base; int cnt, pgadv; td = curthread; if ((td->td_pflags & TDP_UIOHELD) == 0 || uio->uio_segflg != UIO_USERSPACE) return (uiomove_fromphys(ma, offset, xfersize, uio)); KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; iov_base = (vm_offset_t)uio->uio_iov->iov_base; switch (uio->uio_rw) { case UIO_WRITE: pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, offset, cnt); break; case UIO_READ: pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, cnt); break; } pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); td->td_ma += pgadv; KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, pgadv)); td->td_ma_cnt -= pgadv; uio->uio_iov->iov_base = (char *)(iov_base + cnt); uio->uio_iov->iov_len -= cnt; uio->uio_resid -= cnt; uio->uio_offset += cnt; return (0); } /* * File table truncate routine. */ static int vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) { struct mount *mp; struct vnode *vp; void *rl_cookie; int error; vp = fp->f_vnode; retry: /* * Lock the whole range for truncation. Otherwise split i/o * might happen partly before and partly after the truncation. */ rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); error = vn_start_write(vp, &mp, V_WAIT | PCATCH); if (error) goto out1; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); AUDIT_ARG_VNODE1(vp); if (vp->v_type == VDIR) { error = EISDIR; goto out; } #ifdef MAC error = mac_vnode_check_write(active_cred, fp->f_cred, vp); if (error) goto out; #endif error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0, fp->f_cred); out: VOP_UNLOCK(vp); vn_finished_write(mp); out1: vn_rangelock_unlock(vp, rl_cookie); if (error == ERELOOKUP) goto retry; return (error); } /* * Truncate a file that is already locked. */ int vn_truncate_locked(struct vnode *vp, off_t length, bool sync, struct ucred *cred) { struct vattr vattr; int error; error = VOP_ADD_WRITECOUNT(vp, 1); if (error == 0) { VATTR_NULL(&vattr); vattr.va_size = length; if (sync) vattr.va_vaflags |= VA_SYNC; error = VOP_SETATTR(vp, &vattr, cred); VOP_ADD_WRITECOUNT_CHECKED(vp, -1); } return (error); } /* * File table vnode stat routine. */ int vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td) { struct vnode *vp = fp->f_vnode; int error; vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_STAT(vp, sb, active_cred, fp->f_cred, td); VOP_UNLOCK(vp); return (error); } /* * File table vnode ioctl routine. */ static int vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) { struct vattr vattr; struct vnode *vp; struct fiobmap2_arg *bmarg; int error; vp = fp->f_vnode; switch (vp->v_type) { case VDIR: case VREG: switch (com) { case FIONREAD: vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_GETATTR(vp, &vattr, active_cred); VOP_UNLOCK(vp); if (error == 0) *(int *)data = vattr.va_size - fp->f_offset; return (error); case FIOBMAP2: bmarg = (struct fiobmap2_arg *)data; vn_lock(vp, LK_SHARED | LK_RETRY); #ifdef MAC error = mac_vnode_check_read(active_cred, fp->f_cred, vp); if (error == 0) #endif error = VOP_BMAP(vp, bmarg->bn, NULL, &bmarg->bn, &bmarg->runp, &bmarg->runb); VOP_UNLOCK(vp); return (error); case FIONBIO: case FIOASYNC: return (0); default: return (VOP_IOCTL(vp, com, data, fp->f_flag, active_cred, td)); } break; case VCHR: return (VOP_IOCTL(vp, com, data, fp->f_flag, active_cred, td)); default: return (ENOTTY); } } /* * File table vnode poll routine. */ static int vn_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { struct vnode *vp; int error; vp = fp->f_vnode; #if defined(MAC) || defined(AUDIT) if (AUDITING_TD(td) || mac_vnode_check_poll_enabled()) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); AUDIT_ARG_VNODE1(vp); error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); VOP_UNLOCK(vp); if (error != 0) return (error); } #endif error = VOP_POLL(vp, events, fp->f_cred, td); return (error); } /* * Acquire the requested lock and then check for validity. LK_RETRY * permits vn_lock to return doomed vnodes. */ static int __noinline _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line, int error) { KASSERT((flags & LK_RETRY) == 0 || error == 0, ("vn_lock: error %d incompatible with flags %#x", error, flags)); if (error == 0) VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed")); if ((flags & LK_RETRY) == 0) { if (error == 0) { VOP_UNLOCK(vp); error = ENOENT; } return (error); } /* * LK_RETRY case. * * Nothing to do if we got the lock. */ if (error == 0) return (0); /* * Interlock was dropped by the call in _vn_lock. */ flags &= ~LK_INTERLOCK; do { error = VOP_LOCK1(vp, flags, file, line); } while (error != 0); return (0); } int _vn_lock(struct vnode *vp, int flags, const char *file, int line) { int error; VNASSERT((flags & LK_TYPE_MASK) != 0, vp, ("vn_lock: no locktype (%d passed)", flags)); VNPASS(vp->v_holdcnt > 0, vp); error = VOP_LOCK1(vp, flags, file, line); if (__predict_false(error != 0 || VN_IS_DOOMED(vp))) return (_vn_lock_fallback(vp, flags, file, line, error)); return (0); } /* * File table vnode close routine. */ static int vn_closefile(struct file *fp, struct thread *td) { struct vnode *vp; struct flock lf; int error; bool ref; vp = fp->f_vnode; fp->f_ops = &badfileops; - ref = (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE; + ref = (fp->f_flag & FHASLOCK) != 0; error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); if (__predict_false(ref)) { lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); vrele(vp); } return (error); } /* * Preparing to start a filesystem write operation. If the operation is * permitted, then we bump the count of operations in progress and * proceed. If a suspend request is in progress, we wait until the * suspension is over, and then proceed. */ static int vn_start_write_refed(struct mount *mp, int flags, bool mplocked) { struct mount_pcpu *mpcpu; int error, mflags; if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 && vfs_op_thread_enter(mp, mpcpu)) { MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); vfs_mp_count_add_pcpu(mpcpu, writeopcount, 1); vfs_op_thread_exit(mp, mpcpu); return (0); } if (mplocked) mtx_assert(MNT_MTX(mp), MA_OWNED); else MNT_ILOCK(mp); error = 0; /* * Check on status of suspension. */ if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || mp->mnt_susp_owner != curthread) { mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0) | (PUSER - 1); while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { if (flags & V_NOWAIT) { error = EWOULDBLOCK; goto unlock; } error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, "suspfs", 0); if (error) goto unlock; } } if (flags & V_XSLEEP) goto unlock; mp->mnt_writeopcount++; unlock: if (error != 0 || (flags & V_XSLEEP) != 0) MNT_REL(mp); MNT_IUNLOCK(mp); return (error); } int vn_start_write(struct vnode *vp, struct mount **mpp, int flags) { struct mount *mp; int error; KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), ("V_MNTREF requires mp")); error = 0; /* * If a vnode is provided, get and return the mount point that * to which it will write. */ if (vp != NULL) { if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { *mpp = NULL; if (error != EOPNOTSUPP) return (error); return (0); } } if ((mp = *mpp) == NULL) return (0); /* * VOP_GETWRITEMOUNT() returns with the mp refcount held through * a vfs_ref(). * As long as a vnode is not provided we need to acquire a * refcount for the provided mountpoint too, in order to * emulate a vfs_ref(). */ if (vp == NULL && (flags & V_MNTREF) == 0) vfs_ref(mp); return (vn_start_write_refed(mp, flags, false)); } /* * Secondary suspension. Used by operations such as vop_inactive * routines that are needed by the higher level functions. These * are allowed to proceed until all the higher level functions have * completed (indicated by mnt_writeopcount dropping to zero). At that * time, these operations are halted until the suspension is over. */ int vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) { struct mount *mp; int error; KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), ("V_MNTREF requires mp")); retry: if (vp != NULL) { if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { *mpp = NULL; if (error != EOPNOTSUPP) return (error); return (0); } } /* * If we are not suspended or have not yet reached suspended * mode, then let the operation proceed. */ if ((mp = *mpp) == NULL) return (0); /* * VOP_GETWRITEMOUNT() returns with the mp refcount held through * a vfs_ref(). * As long as a vnode is not provided we need to acquire a * refcount for the provided mountpoint too, in order to * emulate a vfs_ref(). */ MNT_ILOCK(mp); if (vp == NULL && (flags & V_MNTREF) == 0) MNT_REF(mp); if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { mp->mnt_secondary_writes++; mp->mnt_secondary_accwrites++; MNT_IUNLOCK(mp); return (0); } if (flags & V_NOWAIT) { MNT_REL(mp); MNT_IUNLOCK(mp); return (EWOULDBLOCK); } /* * Wait for the suspension to finish. */ error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), "suspfs", 0); vfs_rel(mp); if (error == 0) goto retry; return (error); } /* * Filesystem write operation has completed. If we are suspending and this * operation is the last one, notify the suspender that the suspension is * now in effect. */ void vn_finished_write(struct mount *mp) { struct mount_pcpu *mpcpu; int c; if (mp == NULL) return; if (vfs_op_thread_enter(mp, mpcpu)) { vfs_mp_count_sub_pcpu(mpcpu, writeopcount, 1); vfs_mp_count_sub_pcpu(mpcpu, ref, 1); vfs_op_thread_exit(mp, mpcpu); return; } MNT_ILOCK(mp); vfs_assert_mount_counters(mp); MNT_REL(mp); c = --mp->mnt_writeopcount; if (mp->mnt_vfs_ops == 0) { MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); MNT_IUNLOCK(mp); return; } if (c < 0) vfs_dump_mount_counters(mp); if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0) wakeup(&mp->mnt_writeopcount); MNT_IUNLOCK(mp); } /* * Filesystem secondary write operation has completed. If we are * suspending and this operation is the last one, notify the suspender * that the suspension is now in effect. */ void vn_finished_secondary_write(struct mount *mp) { if (mp == NULL) return; MNT_ILOCK(mp); MNT_REL(mp); mp->mnt_secondary_writes--; if (mp->mnt_secondary_writes < 0) panic("vn_finished_secondary_write: neg cnt"); if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && mp->mnt_secondary_writes <= 0) wakeup(&mp->mnt_secondary_writes); MNT_IUNLOCK(mp); } /* * Request a filesystem to suspend write operations. */ int vfs_write_suspend(struct mount *mp, int flags) { int error; vfs_op_enter(mp); MNT_ILOCK(mp); vfs_assert_mount_counters(mp); if (mp->mnt_susp_owner == curthread) { vfs_op_exit_locked(mp); MNT_IUNLOCK(mp); return (EALREADY); } while (mp->mnt_kern_flag & MNTK_SUSPEND) msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); /* * Unmount holds a write reference on the mount point. If we * own busy reference and drain for writers, we deadlock with * the reference draining in the unmount path. Callers of * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if * vfs_busy() reference is owned and caller is not in the * unmount context. */ if ((flags & VS_SKIP_UNMOUNT) != 0 && (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { vfs_op_exit_locked(mp); MNT_IUNLOCK(mp); return (EBUSY); } mp->mnt_kern_flag |= MNTK_SUSPEND; mp->mnt_susp_owner = curthread; if (mp->mnt_writeopcount > 0) (void) msleep(&mp->mnt_writeopcount, MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); else MNT_IUNLOCK(mp); if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) { vfs_write_resume(mp, 0); /* vfs_write_resume does vfs_op_exit() for us */ } return (error); } /* * Request a filesystem to resume write operations. */ void vfs_write_resume(struct mount *mp, int flags) { MNT_ILOCK(mp); if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | MNTK_SUSPENDED); mp->mnt_susp_owner = NULL; wakeup(&mp->mnt_writeopcount); wakeup(&mp->mnt_flag); curthread->td_pflags &= ~TDP_IGNSUSP; if ((flags & VR_START_WRITE) != 0) { MNT_REF(mp); mp->mnt_writeopcount++; } MNT_IUNLOCK(mp); if ((flags & VR_NO_SUSPCLR) == 0) VFS_SUSP_CLEAN(mp); vfs_op_exit(mp); } else if ((flags & VR_START_WRITE) != 0) { MNT_REF(mp); vn_start_write_refed(mp, 0, true); } else { MNT_IUNLOCK(mp); } } /* * Helper loop around vfs_write_suspend() for filesystem unmount VFS * methods. */ int vfs_write_suspend_umnt(struct mount *mp) { int error; KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, ("vfs_write_suspend_umnt: recursed")); /* dounmount() already called vn_start_write(). */ for (;;) { vn_finished_write(mp); error = vfs_write_suspend(mp, 0); if (error != 0) { vn_start_write(NULL, &mp, V_WAIT); return (error); } MNT_ILOCK(mp); if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) break; MNT_IUNLOCK(mp); vn_start_write(NULL, &mp, V_WAIT); } mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); wakeup(&mp->mnt_flag); MNT_IUNLOCK(mp); curthread->td_pflags |= TDP_IGNSUSP; return (0); } /* * Implement kqueues for files by translating it to vnode operation. */ static int vn_kqfilter(struct file *fp, struct knote *kn) { return (VOP_KQFILTER(fp->f_vnode, kn)); } int vn_kqfilter_opath(struct file *fp, struct knote *kn) { if ((fp->f_flag & FKQALLOWED) == 0) return (EBADF); return (vn_kqfilter(fp, kn)); } /* * Simplified in-kernel wrapper calls for extended attribute access. * Both calls pass in a NULL credential, authorizing as "kernel" access. * Set IO_NODELOCKED in ioflg if the vnode is already locked. */ int vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, int *buflen, char *buf, struct thread *td) { struct uio auio; struct iovec iov; int error; iov.iov_len = *buflen; iov.iov_base = buf; auio.uio_iov = &iov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_SYSSPACE; auio.uio_td = td; auio.uio_offset = 0; auio.uio_resid = *buflen; if ((ioflg & IO_NODELOCKED) == 0) vn_lock(vp, LK_SHARED | LK_RETRY); ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); /* authorize attribute retrieval as kernel */ error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, td); if ((ioflg & IO_NODELOCKED) == 0) VOP_UNLOCK(vp); if (error == 0) { *buflen = *buflen - auio.uio_resid; } return (error); } /* * XXX failure mode if partially written? */ int vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, int buflen, char *buf, struct thread *td) { struct uio auio; struct iovec iov; struct mount *mp; int error; iov.iov_len = buflen; iov.iov_base = buf; auio.uio_iov = &iov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_SYSSPACE; auio.uio_td = td; auio.uio_offset = 0; auio.uio_resid = buflen; if ((ioflg & IO_NODELOCKED) == 0) { if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) return (error); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); /* authorize attribute setting as kernel */ error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); if ((ioflg & IO_NODELOCKED) == 0) { vn_finished_write(mp); VOP_UNLOCK(vp); } return (error); } int vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, struct thread *td) { struct mount *mp; int error; if ((ioflg & IO_NODELOCKED) == 0) { if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) return (error); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); /* authorize attribute removal as kernel */ error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); if (error == EOPNOTSUPP) error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, NULL, td); if ((ioflg & IO_NODELOCKED) == 0) { vn_finished_write(mp); VOP_UNLOCK(vp); } return (error); } static int vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, struct vnode **rvp) { return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); } int vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) { return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, lkflags, rvp)); } int vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, int lkflags, struct vnode **rvp) { struct mount *mp; int ltype, error; ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); mp = vp->v_mount; ltype = VOP_ISLOCKED(vp); KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, ("vn_vget_ino: vp not locked")); error = vfs_busy(mp, MBF_NOWAIT); if (error != 0) { vfs_ref(mp); VOP_UNLOCK(vp); error = vfs_busy(mp, 0); vn_lock(vp, ltype | LK_RETRY); vfs_rel(mp); if (error != 0) return (ENOENT); if (VN_IS_DOOMED(vp)) { vfs_unbusy(mp); return (ENOENT); } } VOP_UNLOCK(vp); error = alloc(mp, alloc_arg, lkflags, rvp); vfs_unbusy(mp); if (error != 0 || *rvp != vp) vn_lock(vp, ltype | LK_RETRY); if (VN_IS_DOOMED(vp)) { if (error == 0) { if (*rvp == vp) vunref(vp); else vput(*rvp); } error = ENOENT; } return (error); } int vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, struct thread *td) { off_t lim; bool ktr_write; if (td == NULL) return (0); /* * There are conditions where the limit is to be ignored. * However, since it is almost never reached, check it first. */ ktr_write = (td->td_pflags & TDP_INKTRACE) != 0; lim = lim_cur(td, RLIMIT_FSIZE); if (__predict_false(ktr_write)) lim = td->td_ktr_io_lim; if (__predict_true((uoff_t)uio->uio_offset + uio->uio_resid <= lim)) return (0); /* * The limit is reached. */ if (vp->v_type != VREG || (td->td_pflags2 & TDP2_ACCT) != 0) return (0); if (!ktr_write || ktr_filesize_limit_signal) { PROC_LOCK(td->td_proc); kern_psignal(td->td_proc, SIGXFSZ); PROC_UNLOCK(td->td_proc); } return (EFBIG); } int vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, struct thread *td) { struct vnode *vp; vp = fp->f_vnode; #ifdef AUDIT vn_lock(vp, LK_SHARED | LK_RETRY); AUDIT_ARG_VNODE1(vp); VOP_UNLOCK(vp); #endif return (setfmode(td, active_cred, vp, mode)); } int vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, struct thread *td) { struct vnode *vp; vp = fp->f_vnode; #ifdef AUDIT vn_lock(vp, LK_SHARED | LK_RETRY); AUDIT_ARG_VNODE1(vp); VOP_UNLOCK(vp); #endif return (setfown(td, active_cred, vp, uid, gid)); } void vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) { vm_object_t object; if ((object = vp->v_object) == NULL) return; VM_OBJECT_WLOCK(object); vm_object_page_remove(object, start, end, 0); VM_OBJECT_WUNLOCK(object); } int vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) { struct vattr va; daddr_t bn, bnp; uint64_t bsize; off_t noff; int error; KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, ("Wrong command %lu", cmd)); if (vn_lock(vp, LK_SHARED) != 0) return (EBADF); if (vp->v_type != VREG) { error = ENOTTY; goto unlock; } error = VOP_GETATTR(vp, &va, cred); if (error != 0) goto unlock; noff = *off; if (noff >= va.va_size) { error = ENXIO; goto unlock; } bsize = vp->v_mount->mnt_stat.f_iosize; for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize - noff % bsize) { error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); if (error == EOPNOTSUPP) { error = ENOTTY; goto unlock; } if ((bnp == -1 && cmd == FIOSEEKHOLE) || (bnp != -1 && cmd == FIOSEEKDATA)) { noff = bn * bsize; if (noff < *off) noff = *off; goto unlock; } } if (noff > va.va_size) noff = va.va_size; /* noff == va.va_size. There is an implicit hole at the end of file. */ if (cmd == FIOSEEKDATA) error = ENXIO; unlock: VOP_UNLOCK(vp); if (error == 0) *off = noff; return (error); } int vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) { struct ucred *cred; struct vnode *vp; struct vattr vattr; off_t foffset, size; int error, noneg; cred = td->td_ucred; vp = fp->f_vnode; foffset = foffset_lock(fp, 0); noneg = (vp->v_type != VCHR); error = 0; switch (whence) { case L_INCR: if (noneg && (foffset < 0 || (offset > 0 && foffset > OFF_MAX - offset))) { error = EOVERFLOW; break; } offset += foffset; break; case L_XTND: vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_GETATTR(vp, &vattr, cred); VOP_UNLOCK(vp); if (error) break; /* * If the file references a disk device, then fetch * the media size and use that to determine the ending * offset. */ if (vattr.va_size == 0 && vp->v_type == VCHR && fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) vattr.va_size = size; if (noneg && (vattr.va_size > OFF_MAX || (offset > 0 && vattr.va_size > OFF_MAX - offset))) { error = EOVERFLOW; break; } offset += vattr.va_size; break; case L_SET: break; case SEEK_DATA: error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); if (error == ENOTTY) error = EINVAL; break; case SEEK_HOLE: error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); if (error == ENOTTY) error = EINVAL; break; default: error = EINVAL; } if (error == 0 && noneg && offset < 0) error = EINVAL; if (error != 0) goto drop; VFS_KNOTE_UNLOCKED(vp, 0); td->td_uretoff.tdu_off = offset; drop: foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); return (error); } int vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, struct thread *td) { int error; /* * Grant permission if the caller is the owner of the file, or * the super-user, or has ACL_WRITE_ATTRIBUTES permission on * on the file. If the time pointer is null, then write * permission on the file is also sufficient. * * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES * will be allowed to set the times [..] to the current * server time. */ error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) error = VOP_ACCESS(vp, VWRITE, cred, td); return (error); } int vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) { struct vnode *vp; int error; if (fp->f_type == DTYPE_FIFO) kif->kf_type = KF_TYPE_FIFO; else kif->kf_type = KF_TYPE_VNODE; vp = fp->f_vnode; vref(vp); FILEDESC_SUNLOCK(fdp); error = vn_fill_kinfo_vnode(vp, kif); vrele(vp); FILEDESC_SLOCK(fdp); return (error); } static inline void vn_fill_junk(struct kinfo_file *kif) { size_t len, olen; /* * Simulate vn_fullpath returning changing values for a given * vp during e.g. coredump. */ len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; olen = strlen(kif->kf_path); if (len < olen) strcpy(&kif->kf_path[len - 1], "$"); else for (; olen < len; olen++) strcpy(&kif->kf_path[olen], "A"); } int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) { struct vattr va; char *fullpath, *freepath; int error; kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type); freepath = NULL; fullpath = "-"; error = vn_fullpath(vp, &fullpath, &freepath); if (error == 0) { strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); } if (freepath != NULL) free(freepath, M_TEMP); KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, vn_fill_junk(kif); ); /* * Retrieve vnode attributes. */ va.va_fsid = VNOVAL; va.va_rdev = NODEV; vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_GETATTR(vp, &va, curthread->td_ucred); VOP_UNLOCK(vp); if (error != 0) return (error); if (va.va_fsid != VNOVAL) kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; else kif->kf_un.kf_file.kf_file_fsid = vp->v_mount->mnt_stat.f_fsid.val[0]; kif->kf_un.kf_file.kf_file_fsid_freebsd11 = kif->kf_un.kf_file.kf_file_fsid; /* truncate */ kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); kif->kf_un.kf_file.kf_file_size = va.va_size; kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; kif->kf_un.kf_file.kf_file_rdev_freebsd11 = kif->kf_un.kf_file.kf_file_rdev; /* truncate */ return (0); } int vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, struct thread *td) { #ifdef HWPMC_HOOKS struct pmckern_map_in pkm; #endif struct mount *mp; struct vnode *vp; vm_object_t object; vm_prot_t maxprot; boolean_t writecounted; int error; #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) /* * POSIX shared-memory objects are defined to have * kernel persistence, and are not defined to support * read(2)/write(2) -- or even open(2). Thus, we can * use MAP_ASYNC to trade on-disk coherence for speed. * The shm_open(3) library routine turns on the FPOSIXSHM * flag to request this behavior. */ if ((fp->f_flag & FPOSIXSHM) != 0) flags |= MAP_NOSYNC; #endif vp = fp->f_vnode; /* * Ensure that file and memory protections are * compatible. Note that we only worry about * writability if mapping is shared; in this case, * current and max prot are dictated by the open file. * XXX use the vnode instead? Problem is: what * credentials do we use for determination? What if * proc does a setuid? */ mp = vp->v_mount; if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { maxprot = VM_PROT_NONE; if ((prot & VM_PROT_EXECUTE) != 0) return (EACCES); } else maxprot = VM_PROT_EXECUTE; if ((fp->f_flag & FREAD) != 0) maxprot |= VM_PROT_READ; else if ((prot & VM_PROT_READ) != 0) return (EACCES); /* * If we are sharing potential changes via MAP_SHARED and we * are trying to get write permission although we opened it * without asking for it, bail out. */ if ((flags & MAP_SHARED) != 0) { if ((fp->f_flag & FWRITE) != 0) maxprot |= VM_PROT_WRITE; else if ((prot & VM_PROT_WRITE) != 0) return (EACCES); } else { maxprot |= VM_PROT_WRITE; cap_maxprot |= VM_PROT_WRITE; } maxprot &= cap_maxprot; /* * For regular files and shared memory, POSIX requires that * the value of foff be a legitimate offset within the data * object. In particular, negative offsets are invalid. * Blocking negative offsets and overflows here avoids * possible wraparound or user-level access into reserved * ranges of the data object later. In contrast, POSIX does * not dictate how offsets are used by device drivers, so in * the case of a device mapping a negative offset is passed * on. */ if ( #ifdef _LP64 size > OFF_MAX || #endif foff > OFF_MAX - size) return (EINVAL); writecounted = FALSE; error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, &foff, &object, &writecounted); if (error != 0) return (error); error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, foff, writecounted, td); if (error != 0) { /* * If this mapping was accounted for in the vnode's * writecount, then undo that now. */ if (writecounted) vm_pager_release_writecount(object, 0, size); vm_object_deallocate(object); } #ifdef HWPMC_HOOKS /* Inform hwpmc(4) if an executable is being mapped. */ if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { pkm.pm_file = vp; pkm.pm_address = (uintptr_t) *addr; PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm); } } #endif return (error); } void vn_fsid(struct vnode *vp, struct vattr *va) { fsid_t *f; f = &vp->v_mount->mnt_stat.f_fsid; va->va_fsid = (uint32_t)f->val[1]; va->va_fsid <<= sizeof(f->val[1]) * NBBY; va->va_fsid += (uint32_t)f->val[0]; } int vn_fsync_buf(struct vnode *vp, int waitfor) { struct buf *bp, *nbp; struct bufobj *bo; struct mount *mp; int error, maxretry; error = 0; maxretry = 10000; /* large, arbitrarily chosen */ mp = NULL; if (vp->v_type == VCHR) { VI_LOCK(vp); mp = vp->v_rdev->si_mountpt; VI_UNLOCK(vp); } bo = &vp->v_bufobj; BO_LOCK(bo); loop1: /* * MARK/SCAN initialization to avoid infinite loops. */ TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) { bp->b_vflags &= ~BV_SCANNED; bp->b_error = 0; } /* * Flush all dirty buffers associated with a vnode. */ loop2: TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { if ((bp->b_vflags & BV_SCANNED) != 0) continue; bp->b_vflags |= BV_SCANNED; if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) { if (waitfor != MNT_WAIT) continue; if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL, BO_LOCKPTR(bo)) != 0) { BO_LOCK(bo); goto loop1; } BO_LOCK(bo); } BO_UNLOCK(bo); KASSERT(bp->b_bufobj == bo, ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); if ((bp->b_flags & B_DELWRI) == 0) panic("fsync: not dirty"); if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) { vfs_bio_awrite(bp); } else { bremfree(bp); bawrite(bp); } if (maxretry < 1000) pause("dirty", hz < 1000 ? 1 : hz / 1000); BO_LOCK(bo); goto loop2; } /* * If synchronous the caller expects us to completely resolve all * dirty buffers in the system. Wait for in-progress I/O to * complete (which could include background bitmap writes), then * retry if dirty blocks still exist. */ if (waitfor == MNT_WAIT) { bufobj_wwait(bo, 0, 0); if (bo->bo_dirty.bv_cnt > 0) { /* * If we are unable to write any of these buffers * then we fail now rather than trying endlessly * to write them out. */ TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) if ((error = bp->b_error) != 0) break; if ((mp != NULL && mp->mnt_secondary_writes > 0) || (error == 0 && --maxretry >= 0)) goto loop1; if (error == 0) error = EAGAIN; } } BO_UNLOCK(bo); if (error != 0) vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error); return (error); } /* * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE() * or vn_generic_copy_file_range() after rangelocking the byte ranges, * to do the actual copy. * vn_generic_copy_file_range() is factored out, so it can be called * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from * different file systems. */ int vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred, struct ucred *outcred, struct thread *fsize_td) { int error; size_t len; uint64_t uval; len = *lenp; *lenp = 0; /* For error returns. */ error = 0; /* Do some sanity checks on the arguments. */ if (invp->v_type == VDIR || outvp->v_type == VDIR) error = EISDIR; else if (*inoffp < 0 || *outoffp < 0 || invp->v_type != VREG || outvp->v_type != VREG) error = EINVAL; if (error != 0) goto out; /* Ensure offset + len does not wrap around. */ uval = *inoffp; uval += len; if (uval > INT64_MAX) len = INT64_MAX - *inoffp; uval = *outoffp; uval += len; if (uval > INT64_MAX) len = INT64_MAX - *outoffp; if (len == 0) goto out; /* * If the two vnode are for the same file system, call * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range() * which can handle copies across multiple file systems. */ *lenp = len; if (invp->v_mount == outvp->v_mount) error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp, lenp, flags, incred, outcred, fsize_td); else error = vn_generic_copy_file_range(invp, inoffp, outvp, outoffp, lenp, flags, incred, outcred, fsize_td); out: return (error); } /* * Test len bytes of data starting at dat for all bytes == 0. * Return true if all bytes are zero, false otherwise. * Expects dat to be well aligned. */ static bool mem_iszero(void *dat, int len) { int i; const u_int *p; const char *cp; for (p = dat; len > 0; len -= sizeof(*p), p++) { if (len >= sizeof(*p)) { if (*p != 0) return (false); } else { cp = (const char *)p; for (i = 0; i < len; i++, cp++) if (*cp != '\0') return (false); } } return (true); } /* * Look for a hole in the output file and, if found, adjust *outoffp * and *xferp to skip past the hole. * *xferp is the entire hole length to be written and xfer2 is how many bytes * to be written as 0's upon return. */ static off_t vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp, off_t *dataoffp, off_t *holeoffp, struct ucred *cred) { int error; off_t delta; if (*holeoffp == 0 || *holeoffp <= *outoffp) { *dataoffp = *outoffp; error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred, curthread); if (error == 0) { *holeoffp = *dataoffp; error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred, curthread); } if (error != 0 || *holeoffp == *dataoffp) { /* * Since outvp is unlocked, it may be possible for * another thread to do a truncate(), lseek(), write() * creating a hole at startoff between the above * VOP_IOCTL() calls, if the other thread does not do * rangelocking. * If that happens, *holeoffp == *dataoffp and finding * the hole has failed, so disable vn_skip_hole(). */ *holeoffp = -1; /* Disable use of vn_skip_hole(). */ return (xfer2); } KASSERT(*dataoffp >= *outoffp, ("vn_skip_hole: dataoff=%jd < outoff=%jd", (intmax_t)*dataoffp, (intmax_t)*outoffp)); KASSERT(*holeoffp > *dataoffp, ("vn_skip_hole: holeoff=%jd <= dataoff=%jd", (intmax_t)*holeoffp, (intmax_t)*dataoffp)); } /* * If there is a hole before the data starts, advance *outoffp and * *xferp past the hole. */ if (*dataoffp > *outoffp) { delta = *dataoffp - *outoffp; if (delta >= *xferp) { /* Entire *xferp is a hole. */ *outoffp += *xferp; *xferp = 0; return (0); } *xferp -= delta; *outoffp += delta; xfer2 = MIN(xfer2, *xferp); } /* * If a hole starts before the end of this xfer2, reduce this xfer2 so * that the write ends at the start of the hole. * *holeoffp should always be greater than *outoffp, but for the * non-INVARIANTS case, check this to make sure xfer2 remains a sane * value. */ if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2) xfer2 = *holeoffp - *outoffp; return (xfer2); } /* * Write an xfer sized chunk to outvp in blksize blocks from dat. * dat is a maximum of blksize in length and can be written repeatedly in * the chunk. * If growfile == true, just grow the file via vn_truncate_locked() instead * of doing actual writes. * If checkhole == true, a hole is being punched, so skip over any hole * already in the output file. */ static int vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer, u_long blksize, bool growfile, bool checkhole, struct ucred *cred) { struct mount *mp; off_t dataoff, holeoff, xfer2; int error; /* * Loop around doing writes of blksize until write has been completed. * Lock/unlock on each loop iteration so that a bwillwrite() can be * done for each iteration, since the xfer argument can be very * large if there is a large hole to punch in the output file. */ error = 0; holeoff = 0; do { xfer2 = MIN(xfer, blksize); if (checkhole) { /* * Punching a hole. Skip writing if there is * already a hole in the output file. */ xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer, &dataoff, &holeoff, cred); if (xfer == 0) break; if (holeoff < 0) checkhole = false; KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd", (intmax_t)xfer2)); } bwillwrite(); mp = NULL; error = vn_start_write(outvp, &mp, V_WAIT); if (error != 0) break; if (growfile) { error = vn_lock(outvp, LK_EXCLUSIVE); if (error == 0) { error = vn_truncate_locked(outvp, outoff + xfer, false, cred); VOP_UNLOCK(outvp); } } else { error = vn_lock(outvp, vn_lktype_write(mp, outvp)); if (error == 0) { error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2, outoff, UIO_SYSSPACE, IO_NODELOCKED, curthread->td_ucred, cred, NULL, curthread); outoff += xfer2; xfer -= xfer2; VOP_UNLOCK(outvp); } } if (mp != NULL) vn_finished_write(mp); } while (!growfile && xfer > 0 && error == 0); return (error); } /* * Copy a byte range of one file to another. This function can handle the * case where invp and outvp are on different file systems. * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there * is no better file system specific way to do it. */ int vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred, struct ucred *outcred, struct thread *fsize_td) { struct vattr va, inva; struct mount *mp; struct uio io; off_t startoff, endoff, xfer, xfer2; u_long blksize; int error, interrupted; bool cantseek, readzeros, eof, lastblock, holetoeof; ssize_t aresid; size_t copylen, len, rem, savlen; char *dat; long holein, holeout; struct timespec curts, endts; holein = holeout = 0; savlen = len = *lenp; error = 0; interrupted = 0; dat = NULL; error = vn_lock(invp, LK_SHARED); if (error != 0) goto out; if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0) holein = 0; if (holein > 0) error = VOP_GETATTR(invp, &inva, incred); VOP_UNLOCK(invp); if (error != 0) goto out; mp = NULL; error = vn_start_write(outvp, &mp, V_WAIT); if (error == 0) error = vn_lock(outvp, LK_EXCLUSIVE); if (error == 0) { /* * If fsize_td != NULL, do a vn_rlimit_fsize() call, * now that outvp is locked. */ if (fsize_td != NULL) { io.uio_offset = *outoffp; io.uio_resid = len; error = vn_rlimit_fsize(outvp, &io, fsize_td); if (error != 0) error = EFBIG; } if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0) holeout = 0; /* * Holes that are past EOF do not need to be written as a block * of zero bytes. So, truncate the output file as far as * possible and then use va.va_size to decide if writing 0 * bytes is necessary in the loop below. */ if (error == 0) error = VOP_GETATTR(outvp, &va, outcred); if (error == 0 && va.va_size > *outoffp && va.va_size <= *outoffp + len) { #ifdef MAC error = mac_vnode_check_write(curthread->td_ucred, outcred, outvp); if (error == 0) #endif error = vn_truncate_locked(outvp, *outoffp, false, outcred); if (error == 0) va.va_size = *outoffp; } VOP_UNLOCK(outvp); } if (mp != NULL) vn_finished_write(mp); if (error != 0) goto out; /* * Set the blksize to the larger of the hole sizes for invp and outvp. * If hole sizes aren't available, set the blksize to the larger * f_iosize of invp and outvp. * This code expects the hole sizes and f_iosizes to be powers of 2. * This value is clipped at 4Kbytes and 1Mbyte. */ blksize = MAX(holein, holeout); /* Clip len to end at an exact multiple of hole size. */ if (blksize > 1) { rem = *inoffp % blksize; if (rem > 0) rem = blksize - rem; if (len > rem && len - rem > blksize) len = savlen = rounddown(len - rem, blksize) + rem; } if (blksize <= 1) blksize = MAX(invp->v_mount->mnt_stat.f_iosize, outvp->v_mount->mnt_stat.f_iosize); if (blksize < 4096) blksize = 4096; else if (blksize > 1024 * 1024) blksize = 1024 * 1024; dat = malloc(blksize, M_TEMP, M_WAITOK); /* * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA * to find holes. Otherwise, just scan the read block for all 0s * in the inner loop where the data copying is done. * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may * support holes on the server, but do not support FIOSEEKHOLE. * The kernel flag COPY_FILE_RANGE_TIMEO1SEC is used to indicate * that this function should return after 1second with a partial * completion. */ if ((flags & COPY_FILE_RANGE_TIMEO1SEC) != 0) { getnanouptime(&endts); endts.tv_sec++; } else timespecclear(&endts); holetoeof = eof = false; while (len > 0 && error == 0 && !eof && interrupted == 0) { endoff = 0; /* To shut up compilers. */ cantseek = true; startoff = *inoffp; copylen = len; /* * Find the next data area. If there is just a hole to EOF, * FIOSEEKDATA should fail with ENXIO. * (I do not know if any file system will report a hole to * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA * will fail for those file systems.) * * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE, * the code just falls through to the inner copy loop. */ error = EINVAL; if (holein > 0) { error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0, incred, curthread); if (error == ENXIO) { startoff = endoff = inva.va_size; eof = holetoeof = true; error = 0; } } if (error == 0 && !holetoeof) { endoff = startoff; error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0, incred, curthread); /* * Since invp is unlocked, it may be possible for * another thread to do a truncate(), lseek(), write() * creating a hole at startoff between the above * VOP_IOCTL() calls, if the other thread does not do * rangelocking. * If that happens, startoff == endoff and finding * the hole has failed, so set an error. */ if (error == 0 && startoff == endoff) error = EINVAL; /* Any error. Reset to 0. */ } if (error == 0) { if (startoff > *inoffp) { /* Found hole before data block. */ xfer = MIN(startoff - *inoffp, len); if (*outoffp < va.va_size) { /* Must write 0s to punch hole. */ xfer2 = MIN(va.va_size - *outoffp, xfer); memset(dat, 0, MIN(xfer2, blksize)); error = vn_write_outvp(outvp, dat, *outoffp, xfer2, blksize, false, holeout > 0, outcred); } if (error == 0 && *outoffp + xfer > va.va_size && (xfer == len || holetoeof)) { /* Grow output file (hole at end). */ error = vn_write_outvp(outvp, dat, *outoffp, xfer, blksize, true, false, outcred); } if (error == 0) { *inoffp += xfer; *outoffp += xfer; len -= xfer; if (len < savlen) { interrupted = sig_intr(); if (timespecisset(&endts) && interrupted == 0) { getnanouptime(&curts); if (timespeccmp(&curts, &endts, >=)) interrupted = EINTR; } } } } copylen = MIN(len, endoff - startoff); cantseek = false; } else { cantseek = true; startoff = *inoffp; copylen = len; error = 0; } xfer = blksize; if (cantseek) { /* * Set first xfer to end at a block boundary, so that * holes are more likely detected in the loop below via * the for all bytes 0 method. */ xfer -= (*inoffp % blksize); } /* Loop copying the data block. */ while (copylen > 0 && error == 0 && !eof && interrupted == 0) { if (copylen < xfer) xfer = copylen; error = vn_lock(invp, LK_SHARED); if (error != 0) goto out; error = vn_rdwr(UIO_READ, invp, dat, xfer, startoff, UIO_SYSSPACE, IO_NODELOCKED, curthread->td_ucred, incred, &aresid, curthread); VOP_UNLOCK(invp); lastblock = false; if (error == 0 && aresid > 0) { /* Stop the copy at EOF on the input file. */ xfer -= aresid; eof = true; lastblock = true; } if (error == 0) { /* * Skip the write for holes past the initial EOF * of the output file, unless this is the last * write of the output file at EOF. */ readzeros = cantseek ? mem_iszero(dat, xfer) : false; if (xfer == len) lastblock = true; if (!cantseek || *outoffp < va.va_size || lastblock || !readzeros) error = vn_write_outvp(outvp, dat, *outoffp, xfer, blksize, readzeros && lastblock && *outoffp >= va.va_size, false, outcred); if (error == 0) { *inoffp += xfer; startoff += xfer; *outoffp += xfer; copylen -= xfer; len -= xfer; if (len < savlen) { interrupted = sig_intr(); if (timespecisset(&endts) && interrupted == 0) { getnanouptime(&curts); if (timespeccmp(&curts, &endts, >=)) interrupted = EINTR; } } } } xfer = blksize; } } out: *lenp = savlen - len; free(dat, M_TEMP); return (error); } static int vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td) { struct mount *mp; struct vnode *vp; off_t olen, ooffset; int error; #ifdef AUDIT int audited_vnode1 = 0; #endif vp = fp->f_vnode; if (vp->v_type != VREG) return (ENODEV); /* Allocating blocks may take a long time, so iterate. */ for (;;) { olen = len; ooffset = offset; bwillwrite(); mp = NULL; error = vn_start_write(vp, &mp, V_WAIT | PCATCH); if (error != 0) break; error = vn_lock(vp, LK_EXCLUSIVE); if (error != 0) { vn_finished_write(mp); break; } #ifdef AUDIT if (!audited_vnode1) { AUDIT_ARG_VNODE1(vp); audited_vnode1 = 1; } #endif #ifdef MAC error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp); if (error == 0) #endif error = VOP_ALLOCATE(vp, &offset, &len); VOP_UNLOCK(vp); vn_finished_write(mp); if (olen + ooffset != offset + len) { panic("offset + len changed from %jx/%jx to %jx/%jx", ooffset, olen, offset, len); } if (error != 0 || len == 0) break; KASSERT(olen > len, ("Iteration did not make progress?")); maybe_yield(); } return (error); } static u_long vn_lock_pair_pause_cnt; SYSCTL_ULONG(_debug, OID_AUTO, vn_lock_pair_pause, CTLFLAG_RD, &vn_lock_pair_pause_cnt, 0, "Count of vn_lock_pair deadlocks"); u_int vn_lock_pair_pause_max; SYSCTL_UINT(_debug, OID_AUTO, vn_lock_pair_pause_max, CTLFLAG_RW, &vn_lock_pair_pause_max, 0, "Max ticks for vn_lock_pair deadlock avoidance sleep"); static void vn_lock_pair_pause(const char *wmesg) { atomic_add_long(&vn_lock_pair_pause_cnt, 1); pause(wmesg, prng32_bounded(vn_lock_pair_pause_max)); } /* * Lock pair of vnodes vp1, vp2, avoiding lock order reversal. * vp1_locked indicates whether vp1 is exclusively locked; if not, vp1 * must be unlocked. Same for vp2 and vp2_locked. One of the vnodes * can be NULL. * * The function returns with both vnodes exclusively locked, and * guarantees that it does not create lock order reversal with other * threads during its execution. Both vnodes could be unlocked * temporary (and reclaimed). */ void vn_lock_pair(struct vnode *vp1, bool vp1_locked, struct vnode *vp2, bool vp2_locked) { int error; if (vp1 == NULL && vp2 == NULL) return; if (vp1 != NULL) { if (vp1_locked) ASSERT_VOP_ELOCKED(vp1, "vp1"); else ASSERT_VOP_UNLOCKED(vp1, "vp1"); } else { vp1_locked = true; } if (vp2 != NULL) { if (vp2_locked) ASSERT_VOP_ELOCKED(vp2, "vp2"); else ASSERT_VOP_UNLOCKED(vp2, "vp2"); } else { vp2_locked = true; } if (!vp1_locked && !vp2_locked) { vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY); vp1_locked = true; } for (;;) { if (vp1_locked && vp2_locked) break; if (vp1_locked && vp2 != NULL) { if (vp1 != NULL) { error = VOP_LOCK1(vp2, LK_EXCLUSIVE | LK_NOWAIT, __FILE__, __LINE__); if (error == 0) break; VOP_UNLOCK(vp1); vp1_locked = false; vn_lock_pair_pause("vlp1"); } vn_lock(vp2, LK_EXCLUSIVE | LK_RETRY); vp2_locked = true; } if (vp2_locked && vp1 != NULL) { if (vp2 != NULL) { error = VOP_LOCK1(vp1, LK_EXCLUSIVE | LK_NOWAIT, __FILE__, __LINE__); if (error == 0) break; VOP_UNLOCK(vp2); vp2_locked = false; vn_lock_pair_pause("vlp2"); } vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY); vp1_locked = true; } } if (vp1 != NULL) ASSERT_VOP_ELOCKED(vp1, "vp1 ret"); if (vp2 != NULL) ASSERT_VOP_ELOCKED(vp2, "vp2 ret"); } int vn_lktype_write(struct mount *mp, struct vnode *vp) { if (MNT_SHARED_WRITES(mp) || (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) return (LK_SHARED); return (LK_EXCLUSIVE); }