/* $NetBSD: vfs_vnops.c,v 1.200.4.1 2021/06/21 14:50:57 martin Exp $ */ /*- * Copyright (c) 2009 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Andrew Doran. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * 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. * * 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 8.14 (Berkeley) 6/15/95 */ #include __KERNEL_RCSID(0, "$NetBSD: vfs_vnops.c,v 1.200.4.1 2021/06/21 14:50:57 martin Exp $"); #include "veriexec.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 #ifdef UNION #include #endif #ifndef COMPAT_ZERODEV #define COMPAT_ZERODEV(dev) (0) #endif int (*vn_union_readdir_hook) (struct vnode **, struct file *, struct lwp *); #include static int vn_read(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags); static int vn_write(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags); static int vn_closefile(file_t *fp); static int vn_poll(file_t *fp, int events); static int vn_fcntl(file_t *fp, u_int com, void *data); static int vn_statfile(file_t *fp, struct stat *sb); static int vn_ioctl(file_t *fp, u_long com, void *data); static int vn_mmap(struct file *, off_t *, size_t, int, int *, int *, struct uvm_object **, int *); const struct fileops vnops = { .fo_name = "vn", .fo_read = vn_read, .fo_write = vn_write, .fo_ioctl = vn_ioctl, .fo_fcntl = vn_fcntl, .fo_poll = vn_poll, .fo_stat = vn_statfile, .fo_close = vn_closefile, .fo_kqfilter = vn_kqfilter, .fo_restart = fnullop_restart, .fo_mmap = vn_mmap, }; /* * Common code for vnode open operations. * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. */ int vn_open(struct nameidata *ndp, int fmode, int cmode) { struct vnode *vp; struct lwp *l = curlwp; kauth_cred_t cred = l->l_cred; struct vattr va; int error; const char *pathstring; if ((fmode & (O_CREAT | O_DIRECTORY)) == (O_CREAT | O_DIRECTORY)) return EINVAL; ndp->ni_cnd.cn_flags &= TRYEMULROOT | NOCHROOT; if (fmode & O_CREAT) { ndp->ni_cnd.cn_nameiop = CREATE; ndp->ni_cnd.cn_flags |= LOCKPARENT | LOCKLEAF; if ((fmode & O_EXCL) == 0 && ((fmode & O_NOFOLLOW) == 0)) ndp->ni_cnd.cn_flags |= FOLLOW; if ((fmode & O_EXCL) == 0) ndp->ni_cnd.cn_flags |= NONEXCLHACK; } else { ndp->ni_cnd.cn_nameiop = LOOKUP; ndp->ni_cnd.cn_flags |= LOCKLEAF; if ((fmode & O_NOFOLLOW) == 0) ndp->ni_cnd.cn_flags |= FOLLOW; } pathstring = pathbuf_stringcopy_get(ndp->ni_pathbuf); if (pathstring == NULL) { return ENOMEM; } error = namei(ndp); if (error) goto out; vp = ndp->ni_vp; #if NVERIEXEC > 0 error = veriexec_openchk(l, ndp->ni_vp, pathstring, fmode); if (error) { /* We have to release the locks ourselves */ /* * 20210604 dholland passing NONEXCLHACK means we can * get ni_dvp == NULL back if ni_vp exists, and we should * treat that like the non-O_CREAT case. */ if ((fmode & O_CREAT) != 0 && ndp->ni_dvp != NULL) { if (vp == NULL) { vput(ndp->ni_dvp); } else { VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); if (ndp->ni_dvp == ndp->ni_vp) vrele(ndp->ni_dvp); else vput(ndp->ni_dvp); ndp->ni_dvp = NULL; vput(vp); } } else { vput(vp); } goto out; } #endif /* NVERIEXEC > 0 */ /* * 20210604 dholland ditto */ if ((fmode & O_CREAT) != 0 && ndp->ni_dvp != NULL) { if (ndp->ni_vp == NULL) { vattr_null(&va); va.va_type = VREG; va.va_mode = cmode; if (fmode & O_EXCL) va.va_vaflags |= VA_EXCLUSIVE; error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, &ndp->ni_cnd, &va); if (error) { vput(ndp->ni_dvp); goto out; } fmode &= ~O_TRUNC; vp = ndp->ni_vp; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vput(ndp->ni_dvp); } else { VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 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; } fmode &= ~O_CREAT; } } else if ((fmode & O_CREAT) != 0) { /* * 20210606 dholland passing NONEXCLHACK means this * case exists; it is the same as the following one * but also needs to do things in the second (exists) * half of the following block. (Besides handle * ni_dvp, anyway.) */ vp = ndp->ni_vp; KASSERT((fmode & O_EXCL) == 0); fmode &= ~O_CREAT; } else { vp = ndp->ni_vp; } if (vp->v_type == VSOCK) { error = EOPNOTSUPP; goto bad; } if (ndp->ni_vp->v_type == VLNK) { error = EFTYPE; goto bad; } if ((fmode & O_CREAT) == 0) { error = vn_openchk(vp, cred, fmode); if (error != 0) goto bad; } if (fmode & O_TRUNC) { vattr_null(&va); va.va_size = 0; error = VOP_SETATTR(vp, &va, cred); if (error != 0) goto bad; } if ((error = VOP_OPEN(vp, fmode, cred)) != 0) goto bad; if (fmode & FWRITE) { mutex_enter(vp->v_interlock); vp->v_writecount++; mutex_exit(vp->v_interlock); } bad: if (error) vput(vp); out: pathbuf_stringcopy_put(ndp->ni_pathbuf, pathstring); return (error); } /* * Check for write permissions on the specified vnode. * Prototype text segments cannot be written. */ int vn_writechk(struct vnode *vp) { /* * If the vnode is in use as a process's text, * we can't allow writing. */ if (vp->v_iflag & VI_TEXT) return (ETXTBSY); return (0); } int vn_openchk(struct vnode *vp, kauth_cred_t cred, int fflags) { int permbits = 0; int error; if (vp->v_type == VNON || vp->v_type == VBAD) return ENXIO; if ((fflags & O_DIRECTORY) != 0 && vp->v_type != VDIR) return ENOTDIR; if ((fflags & O_REGULAR) != 0 && vp->v_type != VREG) return EFTYPE; if ((fflags & FREAD) != 0) { permbits = VREAD; } if ((fflags & (FWRITE | O_TRUNC)) != 0) { permbits |= VWRITE; if (vp->v_type == VDIR) { error = EISDIR; goto bad; } error = vn_writechk(vp); if (error != 0) goto bad; } error = VOP_ACCESS(vp, permbits, cred); bad: return error; } /* * Mark a vnode as having executable mappings. */ void vn_markexec(struct vnode *vp) { if ((vp->v_iflag & VI_EXECMAP) != 0) { /* Safe unlocked, as long as caller holds a reference. */ return; } mutex_enter(vp->v_interlock); if ((vp->v_iflag & VI_EXECMAP) == 0) { atomic_add_int(&uvmexp.filepages, -vp->v_uobj.uo_npages); atomic_add_int(&uvmexp.execpages, vp->v_uobj.uo_npages); vp->v_iflag |= VI_EXECMAP; } mutex_exit(vp->v_interlock); } /* * Mark a vnode as being the text of a process. * Fail if the vnode is currently writable. */ int vn_marktext(struct vnode *vp) { if ((vp->v_iflag & (VI_TEXT|VI_EXECMAP)) == (VI_TEXT|VI_EXECMAP)) { /* Safe unlocked, as long as caller holds a reference. */ return (0); } mutex_enter(vp->v_interlock); if (vp->v_writecount != 0) { KASSERT((vp->v_iflag & VI_TEXT) == 0); mutex_exit(vp->v_interlock); return (ETXTBSY); } if ((vp->v_iflag & VI_EXECMAP) == 0) { atomic_add_int(&uvmexp.filepages, -vp->v_uobj.uo_npages); atomic_add_int(&uvmexp.execpages, vp->v_uobj.uo_npages); } vp->v_iflag |= (VI_TEXT | VI_EXECMAP); mutex_exit(vp->v_interlock); return (0); } /* * Vnode close call * * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. */ int vn_close(struct vnode *vp, int flags, kauth_cred_t cred) { int error; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (flags & FWRITE) { mutex_enter(vp->v_interlock); KASSERT(vp->v_writecount > 0); vp->v_writecount--; mutex_exit(vp->v_interlock); } error = VOP_CLOSE(vp, flags, cred); vput(vp); return (error); } static int enforce_rlimit_fsize(struct vnode *vp, struct uio *uio, int ioflag) { struct lwp *l = curlwp; off_t testoff; if (uio->uio_rw != UIO_WRITE || vp->v_type != VREG) return 0; KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); if (ioflag & IO_APPEND) testoff = vp->v_size; else testoff = uio->uio_offset; if (testoff + uio->uio_resid > l->l_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) { mutex_enter(proc_lock); psignal(l->l_proc, SIGXFSZ); mutex_exit(proc_lock); return EFBIG; } 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, kauth_cred_t cred, size_t *aresid, struct lwp *l) { struct uio auio; struct iovec aiov; int error; if ((ioflg & IO_NODELOCKED) == 0) { if (rw == UIO_READ) { vn_lock(vp, LK_SHARED | LK_RETRY); } else /* UIO_WRITE */ { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } } 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_rw = rw; if (segflg == UIO_SYSSPACE) { UIO_SETUP_SYSSPACE(&auio); } else { auio.uio_vmspace = l->l_proc->p_vmspace; } if ((error = enforce_rlimit_fsize(vp, &auio, ioflg)) != 0) goto out; if (rw == UIO_READ) { error = VOP_READ(vp, &auio, ioflg, cred); } else { error = VOP_WRITE(vp, &auio, ioflg, cred); } if (aresid) *aresid = auio.uio_resid; else if (auio.uio_resid && error == 0) error = EIO; out: if ((ioflg & IO_NODELOCKED) == 0) { VOP_UNLOCK(vp); } return (error); } int vn_readdir(file_t *fp, char *bf, int segflg, u_int count, int *done, struct lwp *l, off_t **cookies, int *ncookies) { struct vnode *vp = fp->f_vnode; struct iovec aiov; struct uio auio; int error, eofflag; /* Limit the size on any kernel buffers used by VOP_READDIR */ count = uimin(MAXBSIZE, count); unionread: if (vp->v_type != VDIR) return (EINVAL); aiov.iov_base = bf; aiov.iov_len = count; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_READ; if (segflg == UIO_SYSSPACE) { UIO_SETUP_SYSSPACE(&auio); } else { KASSERT(l == curlwp); auio.uio_vmspace = l->l_proc->p_vmspace; } auio.uio_resid = count; vn_lock(vp, LK_SHARED | LK_RETRY); auio.uio_offset = fp->f_offset; error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, ncookies); mutex_enter(&fp->f_lock); fp->f_offset = auio.uio_offset; mutex_exit(&fp->f_lock); VOP_UNLOCK(vp); if (error) return (error); if (count == auio.uio_resid && vn_union_readdir_hook) { struct vnode *ovp = vp; error = (*vn_union_readdir_hook)(&vp, fp, l); if (error) return (error); if (vp != ovp) goto unionread; } if (count == auio.uio_resid && (vp->v_vflag & VV_ROOT) && (vp->v_mount->mnt_flag & MNT_UNION)) { struct vnode *tvp = vp; vp = vp->v_mount->mnt_vnodecovered; vref(vp); mutex_enter(&fp->f_lock); fp->f_vnode = vp; fp->f_offset = 0; mutex_exit(&fp->f_lock); vrele(tvp); goto unionread; } *done = count - auio.uio_resid; return error; } /* * File table vnode read routine. */ static int vn_read(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags) { struct vnode *vp = fp->f_vnode; int error, ioflag, fflag; size_t count; ioflag = IO_ADV_ENCODE(fp->f_advice); fflag = fp->f_flag; if (fflag & FNONBLOCK) ioflag |= IO_NDELAY; if ((fflag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) ioflag |= IO_SYNC; if (fflag & FALTIO) ioflag |= IO_ALTSEMANTICS; if (fflag & FDIRECT) ioflag |= IO_DIRECT; vn_lock(vp, LK_SHARED | LK_RETRY); uio->uio_offset = *offset; count = uio->uio_resid; error = VOP_READ(vp, uio, ioflag, cred); if (flags & FOF_UPDATE_OFFSET) *offset += count - uio->uio_resid; VOP_UNLOCK(vp); return (error); } /* * File table vnode write routine. */ static int vn_write(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags) { struct vnode *vp = fp->f_vnode; int error, ioflag, fflag; size_t count; ioflag = IO_ADV_ENCODE(fp->f_advice) | IO_UNIT; fflag = fp->f_flag; if (vp->v_type == VREG && (fflag & O_APPEND)) ioflag |= IO_APPEND; if (fflag & FNONBLOCK) ioflag |= IO_NDELAY; if (fflag & FFSYNC || (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) ioflag |= IO_SYNC; else if (fflag & FDSYNC) ioflag |= IO_DSYNC; if (fflag & FALTIO) ioflag |= IO_ALTSEMANTICS; if (fflag & FDIRECT) ioflag |= IO_DIRECT; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); uio->uio_offset = *offset; count = uio->uio_resid; if ((error = enforce_rlimit_fsize(vp, uio, ioflag)) != 0) goto out; error = VOP_WRITE(vp, uio, ioflag, cred); if (flags & FOF_UPDATE_OFFSET) { if (ioflag & IO_APPEND) { /* * SUSv3 describes behaviour for count = 0 as following: * "Before any action ... is taken, and if nbyte is zero * and the file is a regular file, the write() function * ... in the absence of errors ... shall return zero * and have no other results." */ if (count) *offset = uio->uio_offset; } else *offset += count - uio->uio_resid; } out: VOP_UNLOCK(vp); return (error); } /* * File table vnode stat routine. */ static int vn_statfile(file_t *fp, struct stat *sb) { struct vnode *vp = fp->f_vnode; int error; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); error = vn_stat(vp, sb); VOP_UNLOCK(vp); return error; } int vn_stat(struct vnode *vp, struct stat *sb) { struct vattr va; int error; mode_t mode; memset(&va, 0, sizeof(va)); error = VOP_GETATTR(vp, &va, kauth_cred_get()); if (error) return (error); /* * Copy from vattr table */ memset(sb, 0, sizeof(*sb)); sb->st_dev = va.va_fsid; sb->st_ino = va.va_fileid; mode = va.va_mode; switch (vp->v_type) { case VREG: mode |= S_IFREG; break; case VDIR: mode |= S_IFDIR; break; case VBLK: mode |= S_IFBLK; break; case VCHR: mode |= S_IFCHR; break; case VLNK: mode |= S_IFLNK; break; case VSOCK: mode |= S_IFSOCK; break; case VFIFO: mode |= S_IFIFO; break; default: return (EBADF); } sb->st_mode = mode; sb->st_nlink = va.va_nlink; sb->st_uid = va.va_uid; sb->st_gid = va.va_gid; sb->st_rdev = va.va_rdev; sb->st_size = va.va_size; sb->st_atimespec = va.va_atime; sb->st_mtimespec = va.va_mtime; sb->st_ctimespec = va.va_ctime; sb->st_birthtimespec = va.va_birthtime; sb->st_blksize = va.va_blocksize; sb->st_flags = va.va_flags; sb->st_gen = 0; sb->st_blocks = va.va_bytes / S_BLKSIZE; return (0); } /* * File table vnode fcntl routine. */ static int vn_fcntl(file_t *fp, u_int com, void *data) { struct vnode *vp = fp->f_vnode; int error; error = VOP_FCNTL(vp, com, data, fp->f_flag, kauth_cred_get()); return (error); } /* * File table vnode ioctl routine. */ static int vn_ioctl(file_t *fp, u_long com, void *data) { struct vnode *vp = fp->f_vnode, *ovp; struct vattr vattr; int error; switch (vp->v_type) { case VREG: case VDIR: if (com == FIONREAD) { vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_GETATTR(vp, &vattr, kauth_cred_get()); VOP_UNLOCK(vp); if (error) return (error); *(int *)data = vattr.va_size - fp->f_offset; return (0); } if ((com == FIONWRITE) || (com == FIONSPACE)) { /* * Files don't have send queues, so there never * are any bytes in them, nor is there any * open space in them. */ *(int *)data = 0; return (0); } if (com == FIOGETBMAP) { daddr_t *block; if (*(daddr_t *)data < 0) return (EINVAL); block = (daddr_t *)data; return (VOP_BMAP(vp, *block, NULL, block, NULL)); } if (com == OFIOGETBMAP) { daddr_t ibn, obn; if (*(int32_t *)data < 0) return (EINVAL); ibn = (daddr_t)*(int32_t *)data; error = VOP_BMAP(vp, ibn, NULL, &obn, NULL); *(int32_t *)data = (int32_t)obn; return error; } if (com == FIONBIO || com == FIOASYNC) /* XXX */ return (0); /* XXX */ /* FALLTHROUGH */ case VFIFO: case VCHR: case VBLK: error = VOP_IOCTL(vp, com, data, fp->f_flag, kauth_cred_get()); if (error == 0 && com == TIOCSCTTY) { vref(vp); mutex_enter(proc_lock); ovp = curproc->p_session->s_ttyvp; curproc->p_session->s_ttyvp = vp; mutex_exit(proc_lock); if (ovp != NULL) vrele(ovp); } return (error); default: return (EPASSTHROUGH); } } /* * File table vnode poll routine. */ static int vn_poll(file_t *fp, int events) { return (VOP_POLL(fp->f_vnode, events)); } /* * File table vnode kqfilter routine. */ int vn_kqfilter(file_t *fp, struct knote *kn) { return (VOP_KQFILTER(fp->f_vnode, kn)); } static int vn_mmap(struct file *fp, off_t *offp, size_t size, int prot, int *flagsp, int *advicep, struct uvm_object **uobjp, int *maxprotp) { struct uvm_object *uobj; struct vnode *vp; struct vattr va; struct lwp *l; vm_prot_t maxprot; off_t off; int error, flags; bool needwritemap; l = curlwp; off = *offp; flags = *flagsp; maxprot = VM_PROT_EXECUTE; vp = fp->f_vnode; if (vp->v_type != VREG && vp->v_type != VCHR && vp->v_type != VBLK) { /* only REG/CHR/BLK support mmap */ return ENODEV; } if (vp->v_type != VCHR && off < 0) { return EINVAL; } if (vp->v_type != VCHR && (off_t)(off + size) < off) { /* no offset wrapping */ return EOVERFLOW; } /* special case: catch SunOS style /dev/zero */ if (vp->v_type == VCHR && (vp->v_rdev == zerodev || COMPAT_ZERODEV(vp->v_rdev))) { *uobjp = NULL; *maxprotp = VM_PROT_ALL; return 0; } /* * Old programs may not select a specific sharing type, so * default to an appropriate one. * * XXX: how does MAP_ANON fit in the picture? */ if ((flags & (MAP_SHARED|MAP_PRIVATE)) == 0) { #if defined(DEBUG) struct proc *p = l->l_proc; printf("WARNING: defaulted mmap() share type to " "%s (pid %d command %s)\n", vp->v_type == VCHR ? "MAP_SHARED" : "MAP_PRIVATE", p->p_pid, p->p_comm); #endif if (vp->v_type == VCHR) flags |= MAP_SHARED; /* for a device */ else flags |= MAP_PRIVATE; /* for a file */ } /* * MAP_PRIVATE device mappings don't make sense (and aren't * supported anyway). However, some programs rely on this, * so just change it to MAP_SHARED. */ if (vp->v_type == VCHR && (flags & MAP_PRIVATE) != 0) { flags = (flags & ~MAP_PRIVATE) | MAP_SHARED; } /* * now check protection */ /* check read access */ if (fp->f_flag & FREAD) maxprot |= VM_PROT_READ; else if (prot & PROT_READ) { return EACCES; } /* check write access, shared case first */ if (flags & MAP_SHARED) { /* * if the file is writable, only add PROT_WRITE to * maxprot if the file is not immutable, append-only. * otherwise, if we have asked for PROT_WRITE, return * EPERM. */ if (fp->f_flag & FWRITE) { vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_GETATTR(vp, &va, l->l_cred); VOP_UNLOCK(vp); if (error) { return error; } if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) == 0) maxprot |= VM_PROT_WRITE; else if (prot & PROT_WRITE) { return EPERM; } } else if (prot & PROT_WRITE) { return EACCES; } } else { /* MAP_PRIVATE mappings can always write to */ maxprot |= VM_PROT_WRITE; } /* * Don't allow mmap for EXEC if the file system * is mounted NOEXEC. */ if ((prot & PROT_EXEC) != 0 && (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { return EACCES; } if (vp->v_type != VCHR) { error = VOP_MMAP(vp, prot, curlwp->l_cred); if (error) { return error; } vref(vp); uobj = &vp->v_uobj; /* * If the vnode is being mapped with PROT_EXEC, * then mark it as text. */ if (prot & PROT_EXEC) { vn_markexec(vp); } } else { int i = maxprot; /* * XXX Some devices don't like to be mapped with * XXX PROT_EXEC or PROT_WRITE, but we don't really * XXX have a better way of handling this, right now */ do { uobj = udv_attach(vp->v_rdev, (flags & MAP_SHARED) ? i : (i & ~VM_PROT_WRITE), off, size); i--; } while ((uobj == NULL) && (i > 0)); if (uobj == NULL) { return EINVAL; } *advicep = UVM_ADV_RANDOM; } /* * Set vnode flags to indicate the new kinds of mapping. * We take the vnode lock in exclusive mode here to serialize * with direct I/O. * * Safe to check for these flag values without a lock, as * long as a reference to the vnode is held. */ needwritemap = (vp->v_iflag & VI_WRMAP) == 0 && (flags & MAP_SHARED) != 0 && (maxprot & VM_PROT_WRITE) != 0; if ((vp->v_vflag & VV_MAPPED) == 0 || needwritemap) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vp->v_vflag |= VV_MAPPED; if (needwritemap) { mutex_enter(vp->v_interlock); vp->v_iflag |= VI_WRMAP; mutex_exit(vp->v_interlock); } VOP_UNLOCK(vp); } #if NVERIEXEC > 0 /* * Check if the file can be executed indirectly. * * XXX: This gives false warnings about "Incorrect access type" * XXX: if the mapping is not executable. Harmless, but will be * XXX: fixed as part of other changes. */ if (veriexec_verify(l, vp, "(mmap)", VERIEXEC_INDIRECT, NULL)) { /* * Don't allow executable mappings if we can't * indirectly execute the file. */ if (prot & VM_PROT_EXECUTE) { return EPERM; } /* * Strip the executable bit from 'maxprot' to make sure * it can't be made executable later. */ maxprot &= ~VM_PROT_EXECUTE; } #endif /* NVERIEXEC > 0 */ *uobjp = uobj; *maxprotp = maxprot; *flagsp = flags; return 0; } /* * Check that the vnode is still valid, and if so * acquire requested lock. */ int vn_lock(struct vnode *vp, int flags) { int error; #if 0 KASSERT(vp->v_usecount > 0 || (vp->v_iflag & VI_ONWORKLST) != 0); #endif KASSERT((flags & ~(LK_SHARED|LK_EXCLUSIVE|LK_NOWAIT|LK_RETRY)) == 0); KASSERT(!mutex_owned(vp->v_interlock)); #ifdef DIAGNOSTIC if (wapbl_vphaswapbl(vp)) WAPBL_JUNLOCK_ASSERT(wapbl_vptomp(vp)); #endif error = VOP_LOCK(vp, flags); if ((flags & LK_RETRY) != 0 && error == ENOENT) error = VOP_LOCK(vp, flags); KASSERT((flags & LK_RETRY) == 0 || (flags & LK_NOWAIT) != 0 || error == 0); return error; } /* * File table vnode close routine. */ static int vn_closefile(file_t *fp) { return vn_close(fp->f_vnode, fp->f_flag, fp->f_cred); } /* * Simplified in-kernel wrapper calls for extended attribute access. * Both calls pass in a NULL credential, authorizing a "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, size_t *buflen, void *bf, struct lwp *l) { struct uio auio; struct iovec aiov; int error; aiov.iov_len = *buflen; aiov.iov_base = bf; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_READ; auio.uio_offset = 0; auio.uio_resid = *buflen; UIO_SETUP_SYSSPACE(&auio); if ((ioflg & IO_NODELOCKED) == 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL); 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, size_t buflen, const void *bf, struct lwp *l) { struct uio auio; struct iovec aiov; int error; aiov.iov_len = buflen; aiov.iov_base = __UNCONST(bf); /* XXXUNCONST kills const */ auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_WRITE; auio.uio_offset = 0; auio.uio_resid = buflen; UIO_SETUP_SYSSPACE(&auio); if ((ioflg & IO_NODELOCKED) == 0) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL); if ((ioflg & IO_NODELOCKED) == 0) { VOP_UNLOCK(vp); } return (error); } int vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, struct lwp *l) { int error; if ((ioflg & IO_NODELOCKED) == 0) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL); if (error == EOPNOTSUPP) error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, NULL); if ((ioflg & IO_NODELOCKED) == 0) { VOP_UNLOCK(vp); } return (error); } void vn_ra_allocctx(struct vnode *vp) { struct uvm_ractx *ra = NULL; KASSERT(mutex_owned(vp->v_interlock)); if (vp->v_type != VREG) { return; } if (vp->v_ractx != NULL) { return; } if (vp->v_ractx == NULL) { mutex_exit(vp->v_interlock); ra = uvm_ra_allocctx(); mutex_enter(vp->v_interlock); if (ra != NULL && vp->v_ractx == NULL) { vp->v_ractx = ra; ra = NULL; } } if (ra != NULL) { uvm_ra_freectx(ra); } } int vn_fifo_bypass(void *v) { struct vop_generic_args *ap = v; return VOCALL(fifo_vnodeop_p, ap->a_desc->vdesc_offset, v); }