/*      $NetBSD: linux_file.c,v 1.134 2026/06/09 21:45:21 andvar Exp $  */

/*-
 * Copyright (c) 1995, 1998, 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Frank van der Linden and Eric Haszlakiewicz.
 *
 * 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.
 */

/*
 * Functions in multiarch:
 *      linux_sys_llseek        : linux_llseek.c
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_file.c,v 1.134 2026/06/09 21:45:21 andvar Exp $");

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/vfs_syscalls.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/tty.h>
#include <sys/socketvar.h>
#include <sys/conf.h>
#include <sys/pipe.h>
#include <sys/fstrans.h>
#include <sys/syscallargs.h>
#include <sys/vfs_syscalls.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_fcntl.h>
#include <compat/linux/common/linux_util.h>
#include <compat/linux/common/linux_machdep.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>

#include <compat/linux/linux_syscallargs.h>

#ifdef DEBUG_LINUX
#define DPRINTF(a, ...) uprintf(a, __VA_ARGS__)
#else
#define DPRINTF(a, ...)
#endif

#define LINUX_COPY_FILE_RANGE_MAX_CHUNK 8192

static int bsd_to_linux_ioflags(int);
#if !defined(__aarch64__) && !defined(__amd64__)
static void bsd_to_linux_stat(struct stat *, struct linux_stat *);
#endif

conv_linux_flock(linux, flock)

/*
 * Some file-related calls are handled here. The usual flag conversion
 * an structure conversion is done, and alternate emul path searching.
 */

/*
 * The next two functions convert between the Linux and NetBSD values
 * of the flags used in open(2) and fcntl(2).
 */
int
linux_to_bsd_ioflags(int lflags)
{
        int res = 0;

        res |= cvtto_bsd_mask(lflags, LINUX_O_WRONLY, O_WRONLY);
        res |= cvtto_bsd_mask(lflags, LINUX_O_RDONLY, O_RDONLY);
        res |= cvtto_bsd_mask(lflags, LINUX_O_RDWR, O_RDWR);

        res |= cvtto_bsd_mask(lflags, LINUX_O_CREAT, O_CREAT);
        res |= cvtto_bsd_mask(lflags, LINUX_O_EXCL, O_EXCL);
        res |= cvtto_bsd_mask(lflags, LINUX_O_NOCTTY, O_NOCTTY);
        res |= cvtto_bsd_mask(lflags, LINUX_O_TRUNC, O_TRUNC);
        res |= cvtto_bsd_mask(lflags, LINUX_O_APPEND, O_APPEND);
        res |= cvtto_bsd_mask(lflags, LINUX_O_NONBLOCK, O_NONBLOCK);
        res |= cvtto_bsd_mask(lflags, LINUX_O_NDELAY, O_NDELAY);
        res |= cvtto_bsd_mask(lflags, LINUX_O_SYNC, O_FSYNC);
        res |= cvtto_bsd_mask(lflags, LINUX_FASYNC, O_ASYNC);
        res |= cvtto_bsd_mask(lflags, LINUX_O_DIRECT, O_DIRECT);
        res |= cvtto_bsd_mask(lflags, LINUX_O_DIRECTORY, O_DIRECTORY);
        res |= cvtto_bsd_mask(lflags, LINUX_O_NOFOLLOW, O_NOFOLLOW);
        res |= cvtto_bsd_mask(lflags, LINUX_O_CLOEXEC, O_CLOEXEC);

        return res;
}

static int
bsd_to_linux_ioflags(int bflags)
{
        int res = 0;

        res |= cvtto_linux_mask(bflags, O_WRONLY, LINUX_O_WRONLY);
        res |= cvtto_linux_mask(bflags, O_RDONLY, LINUX_O_RDONLY);
        res |= cvtto_linux_mask(bflags, O_RDWR, LINUX_O_RDWR);

        res |= cvtto_linux_mask(bflags, O_CREAT, LINUX_O_CREAT);
        res |= cvtto_linux_mask(bflags, O_EXCL, LINUX_O_EXCL);
        res |= cvtto_linux_mask(bflags, O_NOCTTY, LINUX_O_NOCTTY);
        res |= cvtto_linux_mask(bflags, O_TRUNC, LINUX_O_TRUNC);
        res |= cvtto_linux_mask(bflags, O_APPEND, LINUX_O_APPEND);
        res |= cvtto_linux_mask(bflags, O_NONBLOCK, LINUX_O_NONBLOCK);
        res |= cvtto_linux_mask(bflags, O_NDELAY, LINUX_O_NDELAY);
        res |= cvtto_linux_mask(bflags, O_FSYNC, LINUX_O_SYNC);
        res |= cvtto_linux_mask(bflags, O_ASYNC, LINUX_FASYNC);
        res |= cvtto_linux_mask(bflags, O_DIRECT, LINUX_O_DIRECT);
        res |= cvtto_linux_mask(bflags, O_DIRECTORY, LINUX_O_DIRECTORY);
        res |= cvtto_linux_mask(bflags, O_NOFOLLOW, LINUX_O_NOFOLLOW);
        res |= cvtto_linux_mask(bflags, O_CLOEXEC, LINUX_O_CLOEXEC);

        return res;
}

static inline off_t
linux_hilo_to_off_t(unsigned long hi, unsigned long lo)
{
#ifdef _LP64
        /*
         * Linux discards the "hi" portion on LP64 platforms; even though
         * glibc puts of the upper 32-bits of the offset into the "hi"
         * argument regardless, the "lo" argument has all the bits in
         * this case.
         */
        (void) hi;
        return (off_t)lo;
#else
        return (((off_t)hi) << 32) | lo;
#endif /* _LP64 */
}

#if !defined(__aarch64__)
/*
 * creat(2) is an obsolete function, but it's present as a Linux
 * system call, so let's deal with it.
 *
 * Note: On the Alpha this doesn't really exist in Linux, but it's defined
 * in syscalls.master anyway so this doesn't have to be special cased.
 *
 * Just call open(2) with the TRUNC, CREAT and WRONLY flags.
 */
int
linux_sys_creat(struct lwp *l, const struct linux_sys_creat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(const char *) path;
                syscallarg(linux_umode_t) mode;
        } */
        struct sys_open_args oa;

        SCARG(&oa, path) = SCARG(uap, path);
        SCARG(&oa, flags) = O_CREAT | O_TRUNC | O_WRONLY;
        SCARG(&oa, mode) = SCARG(uap, mode);

        return sys_open(l, &oa, retval);
}
#endif

static void
linux_open_ctty(struct lwp *l, int flags, int fd)
{
        struct proc *p = l->l_proc;

        /*
         * this bit from sunos_misc.c (and svr4_fcntl.c).
         * If we are a session leader, and we don't have a controlling
         * terminal yet, and the O_NOCTTY flag is not set, try to make
         * this the controlling terminal.
         */
        if (!(flags & O_NOCTTY) && SESS_LEADER(p) && !(p->p_lflag & PL_CONTROLT)) {
                file_t *fp;

                fp = fd_getfile(fd);

                /* ignore any error, just give it a try */
                if (fp != NULL) {
                        if (fp->f_type == DTYPE_VNODE) {
                                (fp->f_ops->fo_ioctl) (fp, TIOCSCTTY, NULL);
                        }
                        fd_putfile(fd);
                }
        }
}

/*
 * open(2). Take care of the different flag values, and let the
 * NetBSD syscall do the real work. See if this operation
 * gives the current process a controlling terminal.
 * (XXX is this necessary?)
 */
int
linux_sys_open(struct lwp *l, const struct linux_sys_open_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(const char *) path;
                syscallarg(int) flags;
                syscallarg(linux_umode_t) mode;
        } */
        int error, fl;
        struct sys_open_args boa;

        fl = linux_to_bsd_ioflags(SCARG(uap, flags));

        SCARG(&boa, path) = SCARG(uap, path);
        SCARG(&boa, flags) = fl;
        SCARG(&boa, mode) = SCARG(uap, mode);

        if ((error = sys_open(l, &boa, retval)))
                return (error == EFTYPE) ? ELOOP : error;

        linux_open_ctty(l, fl, *retval);
        return 0;
}

int
linux_sys_openat(struct lwp *l, const struct linux_sys_openat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const char *) path;
                syscallarg(int) flags;
                syscallarg(linux_umode_t) mode;
        } */
        int error, fl;
        struct sys_openat_args boa;

        fl = linux_to_bsd_ioflags(SCARG(uap, flags));

        SCARG(&boa, fd) = SCARG(uap, fd);
        SCARG(&boa, path) = SCARG(uap, path);
        SCARG(&boa, oflags) = fl;
        SCARG(&boa, mode) = SCARG(uap, mode);

        if ((error = sys_openat(l, &boa, retval)))
                return (error == EFTYPE) ? ELOOP : error;

        linux_open_ctty(l, fl, *retval);
        return 0;
}

/*
 * Most actions in the fcntl() call are straightforward; simply
 * pass control to the NetBSD system call. A few commands need
 * conversions after the actual system call has done its work,
 * because the flag values and lock structure are different.
 */
int
linux_sys_fcntl(struct lwp *l, const struct linux_sys_fcntl_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(int) cmd;
                syscallarg(void *) arg;
        } */
        struct proc *p = l->l_proc;
        int fd, cmd, error;
        u_long val;
        void *arg;
        struct sys_fcntl_args fca;
        file_t *fp;
        struct vnode *vp;
        struct vattr va;
        long pgid;
        struct pgrp *pgrp;
        struct tty *tp;

        fd = SCARG(uap, fd);
        cmd = SCARG(uap, cmd);
        arg = SCARG(uap, arg);

        switch (cmd) {

        case LINUX_F_DUPFD:
                cmd = F_DUPFD;
                break;

        case LINUX_F_GETFD:
                cmd = F_GETFD;
                break;

        case LINUX_F_SETFD:
                cmd = F_SETFD;
                break;

        case LINUX_F_GETFL:
                SCARG(&fca, fd) = fd;
                SCARG(&fca, cmd) = F_GETFL;
                SCARG(&fca, arg) = arg;
                if ((error = sys_fcntl(l, &fca, retval)))
                        return error;
                retval[0] = bsd_to_linux_ioflags(retval[0]);
                return 0;

        case LINUX_F_SETFL: {
                file_t  *fp1 = NULL;

                val = linux_to_bsd_ioflags((unsigned long)SCARG(uap, arg));
                /*
                 * Linux seems to have same semantics for sending SIGIO to the
                 * read side of socket, but slightly different semantics
                 * for SIGIO to the write side.  Rather than sending the SIGIO
                 * every time it's possible to write (directly) more data, it
                 * only sends SIGIO if last write(2) failed due to insufficient
                 * memory to hold the data. This is compatible enough
                 * with NetBSD semantics to not do anything about the
                 * difference.
                 *
                 * Linux does NOT send SIGIO for pipes. Deal with socketpair
                 * ones and DTYPE_PIPE ones. For these, we don't set
                 * the underlying flags (we don't pass O_ASYNC flag down
                 * to sys_fcntl()), but set the FASYNC flag for file descriptor,
                 * so that F_GETFL would report the ASYNC i/o is on.
                 */
                if (val & O_ASYNC) {
                        if (((fp1 = fd_getfile(fd)) == NULL))
                            return (EBADF);
                        if (((fp1->f_type == DTYPE_SOCKET) && fp1->f_data
                              && ((struct socket *)fp1->f_data)->so_state & SS_ISAPIPE)
                            || (fp1->f_type == DTYPE_PIPE))
                                val &= ~O_ASYNC;
                        else {
                                /* not a pipe, do not modify anything */
                                fd_putfile(fd);
                                fp1 = NULL;
                        }
                }

                SCARG(&fca, fd) = fd;
                SCARG(&fca, cmd) = F_SETFL;
                SCARG(&fca, arg) = (void *) val;

                error = sys_fcntl(l, &fca, retval);

                /* Now set the FASYNC flag for pipes */
                if (fp1) {
                        if (!error) {
                                mutex_enter(&fp1->f_lock);
                                fp1->f_flag |= FASYNC;
                                mutex_exit(&fp1->f_lock);
                        }
                        fd_putfile(fd);
                }

                return (error);
            }

        case LINUX_F_GETLK:
                do_linux_getlk(fd, cmd, arg, linux, flock);

        case LINUX_F_SETLK:
        case LINUX_F_SETLKW:
                do_linux_setlk(fd, cmd, arg, linux, flock, LINUX_F_SETLK);

        case LINUX_F_SETOWN:
        case LINUX_F_GETOWN:
                /*
                 * We need to route fcntl() for tty descriptors around normal
                 * fcntl(), since NetBSD tty TIOC{G,S}PGRP semantics is too
                 * restrictive for Linux F_{G,S}ETOWN. For non-tty descriptors,
                 * this is not a problem.
                 */
                if ((fp = fd_getfile(fd)) == NULL)
                        return EBADF;

                /* Check it's a character device vnode */
                if (fp->f_type != DTYPE_VNODE
                    || (vp = (struct vnode *)fp->f_data) == NULL
                    || vp->v_type != VCHR) {
                        fd_putfile(fd);

            not_tty:
                        /* Not a tty, proceed with common fcntl() */
                        cmd = cmd == LINUX_F_SETOWN ? F_SETOWN : F_GETOWN;
                        break;
                }

                vn_lock(vp, LK_SHARED | LK_RETRY);
                error = VOP_GETATTR(vp, &va, l->l_cred);
                VOP_UNLOCK(vp);

                fd_putfile(fd);

                if (error)
                        return error;

                if ((tp = cdev_tty(va.va_rdev)) == NULL)
                        goto not_tty;

                /* set tty pg_id appropriately */
                mutex_enter(&proc_lock);
                if (cmd == LINUX_F_GETOWN) {
                        retval[0] = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PGID;
                        mutex_exit(&proc_lock);
                        return 0;
                }
                if ((long)arg <= 0) {
                        pgid = -(long)arg;
                } else {
                        struct proc *p1 = proc_find((long)arg);
                        if (p1 == NULL) {
                                mutex_exit(&proc_lock);
                                return (ESRCH);
                        }
                        pgid = (long)p1->p_pgrp->pg_id;
                }
                pgrp = pgrp_find(pgid);
                if (pgrp == NULL || pgrp->pg_session != p->p_session) {
                        mutex_exit(&proc_lock);
                        return EPERM;
                }
                tp->t_pgrp = pgrp;
                mutex_exit(&proc_lock);
                return 0;

        case LINUX_F_DUPFD_CLOEXEC:
                cmd = F_DUPFD_CLOEXEC;
                break;

        case LINUX_F_ADD_SEALS:
                cmd = F_ADD_SEALS;
                break;

        case LINUX_F_GET_SEALS:
                cmd = F_GET_SEALS;
                break;

        default:
                return EOPNOTSUPP;
        }

        SCARG(&fca, fd) = fd;
        SCARG(&fca, cmd) = cmd;
        SCARG(&fca, arg) = arg;

        return sys_fcntl(l, &fca, retval);
}

#if !defined(__aarch64__) && !defined(__amd64__)
/*
 * Convert a NetBSD stat structure to a Linux stat structure.
 * Only the order of the fields and the padding in the structure
 * is different. linux_fakedev is a machine-dependent function
 * which optionally converts device driver major/minor numbers
 * (XXX horrible, but what can you do against code that compares
 * things against constant major device numbers? sigh)
 */
static void
bsd_to_linux_stat(struct stat *bsp, struct linux_stat *lsp)
{

        memset(lsp, 0, sizeof(*lsp));
        lsp->lst_dev     = linux_fakedev(bsp->st_dev, 0);
        lsp->lst_ino     = bsp->st_ino;
        lsp->lst_mode    = (linux_mode_t)bsp->st_mode;
        if (bsp->st_nlink >= (1 << 15))
                lsp->lst_nlink = (1 << 15) - 1;
        else
                lsp->lst_nlink = (linux_nlink_t)bsp->st_nlink;
        lsp->lst_uid     = bsp->st_uid;
        lsp->lst_gid     = bsp->st_gid;
        lsp->lst_rdev    = linux_fakedev(bsp->st_rdev, 1);
        lsp->lst_size    = bsp->st_size;
        lsp->lst_blksize = bsp->st_blksize;
        lsp->lst_blocks  = bsp->st_blocks;
        lsp->lst_atime   = bsp->st_atime;
        lsp->lst_mtime   = bsp->st_mtime;
        lsp->lst_ctime   = bsp->st_ctime;
#ifdef LINUX_STAT_HAS_NSEC
        lsp->lst_atime_nsec   = bsp->st_atimensec;
        lsp->lst_mtime_nsec   = bsp->st_mtimensec;
        lsp->lst_ctime_nsec   = bsp->st_ctimensec;
#endif
}

/*
 * The stat functions below are plain sailing. stat and lstat are handled
 * by one function to avoid code duplication.
 */
int
linux_sys_fstat(struct lwp *l, const struct linux_sys_fstat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(linux_stat *) sp;
        } */
        struct linux_stat tmplst;
        struct stat tmpst;
        int error;

        error = do_sys_fstat(SCARG(uap, fd), &tmpst);
        if (error != 0)
                return error;
        bsd_to_linux_stat(&tmpst, &tmplst);

        return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
}

static int
linux_stat1(const struct linux_sys_stat_args *uap, register_t *retval,
    int flags)
{
        struct linux_stat tmplst;
        struct stat tmpst;
        int error;

        error = do_sys_stat(SCARG(uap, path), flags, &tmpst);
        if (error != 0)
                return error;

        bsd_to_linux_stat(&tmpst, &tmplst);

        return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
}

int
linux_sys_stat(struct lwp *l, const struct linux_sys_stat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(const char *) path;
                syscallarg(struct linux_stat *) sp;
        } */

        return linux_stat1(uap, retval, FOLLOW);
}

/* Note: this is "newlstat" in the Linux sources */
/*      (we don't bother with the old lstat currently) */
int
linux_sys_lstat(struct lwp *l, const struct linux_sys_lstat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(const char *) path;
                syscallarg(struct linux_stat *) sp;
        } */

        return linux_stat1((const void *)uap, retval, NOFOLLOW);
}
#endif /* !__aarch64__ && !__amd64__ */

/*
 * The following syscalls are mostly here because of the alternate path check.
 */

int
linux_sys_linkat(struct lwp *l, const struct linux_sys_linkat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd1;
                syscallarg(const char *) name1;
                syscallarg(int) fd2;
                syscallarg(const char *) name2;
                syscallarg(int) flags;
        } */
        int fd1 = SCARG(uap, fd1);
        const char *name1 = SCARG(uap, name1);
        int fd2 = SCARG(uap, fd2);
        const char *name2 = SCARG(uap, name2);
        int follow;

        follow = SCARG(uap, flags) & LINUX_AT_SYMLINK_FOLLOW;

        return do_sys_linkat(l, fd1, name1, fd2, name2, follow, retval);
}

static int
linux_unlink_dircheck(const char *path)
{
        struct nameidata nd;
        struct pathbuf *pb;
        int error;

        /*
         * Linux returns EISDIR if unlink(2) is called on a directory.
         * We return EPERM in such cases. To emulate correct behaviour,
         * check if the path points to directory and return EISDIR if this
         * is the case.
         *
         * XXX this should really not copy in the path buffer twice...
         */
        error = pathbuf_copyin(path, &pb);
        if (error) {
                return error;
        }
        NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb);
        if (namei(&nd) == 0) {
                struct stat sb;

                if (vn_stat(nd.ni_vp, &sb) == 0
                    && S_ISDIR(sb.st_mode))
                        error = EISDIR;

                vput(nd.ni_vp);
        }
        pathbuf_destroy(pb);
        return error ? error : EPERM;
}

int
linux_sys_unlink(struct lwp *l, const struct linux_sys_unlink_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(const char *) path;
        } */
        int error;

        error = sys_unlink(l, (const void *)uap, retval);
        if (error == EPERM)
                error = linux_unlink_dircheck(SCARG(uap, path));

        return error;
}

int
linux_sys_unlinkat(struct lwp *l, const struct linux_sys_unlinkat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const char *) path;
                syscallarg(int) flag;
        } */
        struct sys_unlinkat_args ua;
        int error;

        SCARG(&ua, fd) = SCARG(uap, fd);
        SCARG(&ua, path) = SCARG(uap, path);
        SCARG(&ua, flag) = linux_to_bsd_atflags(SCARG(uap, flag));

        error = sys_unlinkat(l, &ua, retval);
        if (error == EPERM)
                error = linux_unlink_dircheck(SCARG(uap, path));

        return error;
}

int
linux_sys_mknod(struct lwp *l, const struct linux_sys_mknod_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(const char *) path;
                syscallarg(linux_umode_t) mode;
                syscallarg(unsigned) dev;
        } */
        struct linux_sys_mknodat_args ua;

        SCARG(&ua, fd) = LINUX_AT_FDCWD;
        SCARG(&ua, path) = SCARG(uap, path);
        SCARG(&ua, mode) = SCARG(uap, mode);
        SCARG(&ua, dev) = SCARG(uap, dev);

        return linux_sys_mknodat(l, &ua, retval);
}

int
linux_sys_mknodat(struct lwp *l, const struct linux_sys_mknodat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const char *) path;
                syscallarg(linux_umode_t) mode;
                syscallarg(unsigned) dev;
        } */

        /*
         * BSD handles FIFOs separately
         */
        if (S_ISFIFO(SCARG(uap, mode))) {
                struct sys_mkfifoat_args bma;

                SCARG(&bma, fd) = SCARG(uap, fd);
                SCARG(&bma, path) = SCARG(uap, path);
                SCARG(&bma, mode) = SCARG(uap, mode);
                return sys_mkfifoat(l, &bma, retval);
        } else {

                /*
                 * Linux device numbers uses 8 bits for minor and 8 bits
                 * for major. Due to how we map our major and minor,
                 * this just fits into our dev_t. Just mask off the
                 * upper 16bit to remove any random junk.
                 */

                return do_sys_mknodat(l, SCARG(uap, fd), SCARG(uap, path),
                    SCARG(uap, mode), SCARG(uap, dev) & 0xffff, UIO_USERSPACE);
        }
}

int
linux_sys_fchmodat(struct lwp *l, const struct linux_sys_fchmodat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const char *) path;
                syscallarg(linux_umode_t) mode;
        } */

        return do_sys_chmodat(l, SCARG(uap, fd), SCARG(uap, path),
                              SCARG(uap, mode), AT_SYMLINK_FOLLOW);
}

int
linux_sys_fchownat(struct lwp *l, const struct linux_sys_fchownat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const char *) path;
                syscallarg(uid_t) owner;
                syscallarg(gid_t) group;
                syscallarg(int) flag;
        } */
        int flag;

        flag = linux_to_bsd_atflags(SCARG(uap, flag));
        return do_sys_chownat(l, SCARG(uap, fd), SCARG(uap, path),
                              SCARG(uap, owner), SCARG(uap, group), flag);
}

int
linux_sys_faccessat(struct lwp *l, const struct linux_sys_faccessat_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const char *) path;
                syscallarg(int) amode;
        } */

        return do_sys_accessat(l, SCARG(uap, fd), SCARG(uap, path),
             SCARG(uap, amode), AT_SYMLINK_FOLLOW);
}

/*
 * This is just fsync() for now (just as it is in the Linux kernel)
 * Note: this is not implemented under Linux on Alpha and Arm
 *      but should still be defined in our syscalls.master.
 *      (syscall #148 on the arm)
 */
int
linux_sys_fdatasync(struct lwp *l, const struct linux_sys_fdatasync_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
        } */

        return sys_fsync(l, (const void *)uap, retval);
}

/*
 * pread(2).
 */
int
linux_sys_pread(struct lwp *l, const struct linux_sys_pread_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(void *) buf;
                syscallarg(size_t) nbyte;
                syscallarg(off_t) offset;
        } */
        struct sys_pread_args pra;

        SCARG(&pra, fd) = SCARG(uap, fd);
        SCARG(&pra, buf) = SCARG(uap, buf);
        SCARG(&pra, nbyte) = SCARG(uap, nbyte);
        SCARG(&pra, PAD) = 0;
        SCARG(&pra, offset) = SCARG(uap, offset);

        return sys_pread(l, &pra, retval);
}

/*
 * pwrite(2).
 */
int
linux_sys_pwrite(struct lwp *l, const struct linux_sys_pwrite_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(void *) buf;
                syscallarg(size_t) nbyte;
                syscallarg(off_t) offset;
        } */
        struct sys_pwrite_args pra;

        SCARG(&pra, fd) = SCARG(uap, fd);
        SCARG(&pra, buf) = SCARG(uap, buf);
        SCARG(&pra, nbyte) = SCARG(uap, nbyte);
        SCARG(&pra, PAD) = 0;
        SCARG(&pra, offset) = SCARG(uap, offset);

        return sys_pwrite(l, &pra, retval);
}

/*
 * preadv(2)
 */
int
linux_sys_preadv(struct lwp *l, const struct linux_sys_preadv_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const struct iovec *) iovp;
                syscallarg(int) iovcnt;
                syscallarg(unsigned long) off_lo;
                syscallarg(unsigned long) off_hi;
        } */
        struct sys_preadv_args ua;

        SCARG(&ua, fd) = SCARG(uap, fd);
        SCARG(&ua, iovp) = SCARG(uap, iovp);
        SCARG(&ua, iovcnt) = SCARG(uap, iovcnt);
        SCARG(&ua, PAD) = 0;
        SCARG(&ua, offset) = linux_hilo_to_off_t(SCARG(uap, off_hi),
                                                 SCARG(uap, off_lo));
        return sys_preadv(l, &ua, retval);
}

/*
 * pwritev(2)
 */
int
linux_sys_pwritev(struct lwp *l, const struct linux_sys_pwritev_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const struct iovec *) iovp;
                syscallarg(int) iovcnt;
                syscallarg(unsigned long) off_lo;
                syscallarg(unsigned long) off_hi;
        } */
        struct sys_pwritev_args ua;

        SCARG(&ua, fd) = SCARG(uap, fd);
        SCARG(&ua, iovp) = (const void *)SCARG(uap, iovp);
        SCARG(&ua, iovcnt) = SCARG(uap, iovcnt);
        SCARG(&ua, PAD) = 0;
        SCARG(&ua, offset) = linux_hilo_to_off_t(SCARG(uap, off_hi),
                                                 SCARG(uap, off_lo));
        return sys_pwritev(l, &ua, retval);
}

int
linux_sys_dup3(struct lwp *l, const struct linux_sys_dup3_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) from;
                syscallarg(int) to;
                syscallarg(int) flags;
        } */
        int flags;

        flags = linux_to_bsd_ioflags(SCARG(uap, flags));
        if ((flags & ~O_CLOEXEC) != 0)
                return EINVAL;

        if (SCARG(uap, from) == SCARG(uap, to))
                return EINVAL;

        return dodup(l, SCARG(uap, from), SCARG(uap, to), flags, retval);
}

int
linux_to_bsd_atflags(int lflags)
{
        int bflags = 0;

        if (lflags & LINUX_AT_SYMLINK_NOFOLLOW)
                bflags |= AT_SYMLINK_NOFOLLOW;
        if (lflags & LINUX_AT_REMOVEDIR)
                bflags |= AT_REMOVEDIR;
        if (lflags & LINUX_AT_SYMLINK_FOLLOW)
                bflags |= AT_SYMLINK_FOLLOW;

        return bflags;
}

int
linux_sys_faccessat2(lwp_t *l, const struct linux_sys_faccessat2_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(const char *) path;
                syscallarg(int) amode;
                syscallarg(int) flags;
        } */
        int flag = linux_to_bsd_atflags(SCARG(uap, flags));
        int mode = SCARG(uap, amode);
        int fd = SCARG(uap, fd);
        const char *path = SCARG(uap, path);

        return do_sys_accessat(l, fd, path, mode, flag);
}

int
linux_sys_sync_file_range(lwp_t *l,
    const struct linux_sys_sync_file_range_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(off_t) offset;
                syscallarg(off_t) nbytes;
                syscallarg(unsigned int) flags;
        } */

        struct sys_fsync_range_args ua;

        if (SCARG(uap, offset) < 0 || SCARG(uap, nbytes) < 0 ||
            ((SCARG(uap, flags) & ~LINUX_SYNC_FILE_RANGE_ALL) != 0))
                return EINVAL;

        /* Fill ua with uap */
        SCARG(&ua, fd) = SCARG(uap, fd);
        SCARG(&ua, flags) = SCARG(uap, flags);

        /* Round down offset to page boundary */
        SCARG(&ua, start) = rounddown(SCARG(uap, offset), PAGE_SIZE);
        SCARG(&ua, length) = SCARG(uap, nbytes);
        if (SCARG(&ua, length) != 0) {
                /* Round up length to nbytes+offset to page boundary */
                SCARG(&ua, length) = roundup(SCARG(uap, nbytes)
                    + SCARG(uap, offset) - SCARG(&ua, start), PAGE_SIZE);
        }

        return sys_fsync_range(l, &ua, retval);
}

int
linux_sys_syncfs(lwp_t *l, const struct linux_sys_syncfs_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fd;
        } */

        struct mount *mp;
        struct vnode *vp;
        file_t *fp;
        int error, fd;
        fd = SCARG(uap, fd);

        /* Get file pointer */
        if ((error = fd_getvnode(fd, &fp)) != 0)
                return error;

        /* Get vnode and mount point */
        vp = fp->f_vnode;
        mp = vp->v_mount;

        mutex_enter(mp->mnt_updating);
        if ((mp->mnt_flag & MNT_RDONLY) == 0) {
                int asyncflag = mp->mnt_flag & MNT_ASYNC;
                mp->mnt_flag &= ~MNT_ASYNC;
                VFS_SYNC(mp, MNT_NOWAIT, l->l_cred);
                if (asyncflag)
                        mp->mnt_flag |= MNT_ASYNC;
        }
        mutex_exit(mp->mnt_updating);

        /* Cleanup vnode and file pointer */
        vrele(vp);
        fd_putfile(fd);
        return 0;

}

int
linux_sys_renameat2(struct lwp *l, const struct linux_sys_renameat2_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) fromfd;
                syscallarg(const char *) from;
                syscallarg(int) tofd;
                syscallarg(const char *) to;
                syscallarg(unsigned int) flags;
        } */

        struct sys_renameat_args ua;
        SCARG(&ua, fromfd) = SCARG(uap, fromfd);
        SCARG(&ua, from) = SCARG(uap, from);
        SCARG(&ua, tofd) = SCARG(uap, tofd);
        SCARG(&ua, to) = SCARG(uap, to);

        unsigned int flags = SCARG(uap, flags);
        int error;

        if (flags != 0) {
                if (flags & ~LINUX_RENAME_ALL)
                        return EINVAL;
                if ((flags & LINUX_RENAME_EXCHANGE) != 0 &&
                    (flags & (LINUX_RENAME_NOREPLACE | LINUX_RENAME_WHITEOUT))
                    != 0)
                        return EINVAL;
                /*
                 * Suppoting renameat2 flags without support from file systems
                 * becomes a messy affair cause of locks and how VOP_RENAME
                 * protocol is implemented. So, return EOPNOTSUPP for now.
                 */
                return EOPNOTSUPP;
        }

        error = sys_renameat(l, &ua, retval);
        return error;
}

int
linux_sys_copy_file_range(lwp_t *l,
    const struct linux_sys_copy_file_range_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) fd_in;
                syscallarg(unsigned long) off_in;
                syscallarg(int) fd_out;
                syscallarg(unsigned long) off_out;
                syscallarg(size_t) len;
                syscallarg(unsigned int) flags;
        } */
        const off_t OFF_MAX = __type_max(off_t);
        int fd_in, fd_out;
        file_t *fp_in, *fp_out;
        struct vnode *invp, *outvp;
        off_t off_in = 0, off_out = 0;
        struct vattr vattr_in, vattr_out;
        ssize_t total_copied = 0;
        size_t bytes_left, to_copy;
        bool have_off_in = false, have_off_out = false;
        int error = 0;
        size_t len = SCARG(uap, len);
        unsigned int flags = SCARG(uap, flags);
        /* Structures for actual copy */
        char *buffer = NULL;
        struct uio auio;
        struct iovec aiov;

        if (len > SSIZE_MAX) {
                DPRINTF("%s: len is greater than SSIZE_MAX\n",
                    __func__);
                return EOVERFLOW;
        }

        if (flags != 0) {
                DPRINTF("%s: unsupported flags %#x\n", __func__, flags);
                return EINVAL;
        }

        fd_in = SCARG(uap, fd_in);
        fd_out = SCARG(uap, fd_out);
        error = fd_getvnode(fd_in, &fp_in);
        if (error) {
                return error;
        }

        error = fd_getvnode(fd_out, &fp_out);
        if (error) {
                fd_putfile(fd_in);
                return error;
        }

        invp = fp_in->f_vnode;
        outvp = fp_out->f_vnode;

        /* Get attributes of input and output files */
        VOP_GETATTR(invp, &vattr_in, l->l_cred);
        VOP_GETATTR(outvp, &vattr_out, l->l_cred);

        /* Check if input and output files are regular files */
        if (vattr_in.va_type == VDIR || vattr_out.va_type == VDIR) {
                error = EISDIR;
                DPRINTF("%s: Input or output is a directory\n", __func__);
                goto out;
        }
        if ((SCARG(uap, off_in) != NULL && *SCARG(uap, off_in) < 0) ||
            (SCARG(uap, off_out) != NULL && *SCARG(uap, off_out) < 0) ||
            vattr_in.va_type != VREG || vattr_out.va_type != VREG) {
                error = EINVAL;
                DPRINTF("%s: Invalid offset or file type\n", __func__);
                goto out;
        }

        if ((fp_in->f_flag & FREAD) == 0 ||
            (fp_out->f_flag & FWRITE) == 0 ||
            (fp_out->f_flag & FAPPEND) != 0) {
                DPRINTF("%s: input file can't be read or output file "
                    "can't be written\n", __func__);
                error = EBADF;
                goto out;
        }
        /* Retrieve and validate offsets if provided */
        if (SCARG(uap, off_in) != NULL) {
                error = copyin(SCARG(uap, off_in), &off_in, sizeof(off_in));
                if (error) {
                        goto out;
                }
                have_off_in = true;
        }

        if (SCARG(uap, off_out) != NULL) {
                error = copyin(SCARG(uap, off_out), &off_out, sizeof(off_out));
                if (error) {
                        goto out;
                }
                have_off_out = true;
        }

        if (off_out < 0 || len > OFF_MAX - off_out ||
            off_in < 0 || len > OFF_MAX - off_in) {
                DPRINTF("%s: New size is greater than OFF_MAX\n", __func__);
                error = EFBIG;
                goto out;
        }

        /* Identify overlapping ranges */
        if ((invp == outvp) &&
            ((off_in <= off_out && off_in + (off_t)len > off_out) ||
                (off_in > off_out && off_out + (off_t)len > off_in))) {
                DPRINTF("%s: Ranges overlap\n", __func__);
                error = EINVAL;
                goto out;
        }

        buffer = kmem_alloc(LINUX_COPY_FILE_RANGE_MAX_CHUNK, KM_SLEEP);

        bytes_left = len;

        while (bytes_left > 0) {
                to_copy = MIN(bytes_left, LINUX_COPY_FILE_RANGE_MAX_CHUNK);

                /* Lock the input vnode for reading */
                vn_lock(fp_in->f_vnode, LK_SHARED | LK_RETRY);
                /* Set up iovec and uio for reading */
                aiov.iov_base = buffer;
                aiov.iov_len = to_copy;
                auio.uio_iov = &aiov;
                auio.uio_iovcnt = 1;
                auio.uio_offset = have_off_in ? off_in : fp_in->f_offset;
                auio.uio_resid = to_copy;
                auio.uio_rw = UIO_READ;
                auio.uio_vmspace = l->l_proc->p_vmspace;
                UIO_SETUP_SYSSPACE(&auio);

                /* Perform read using vn_read */
                error = VOP_READ(fp_in->f_vnode, &auio, 0, l->l_cred);
                VOP_UNLOCK(fp_in->f_vnode);
                if (error) {
                        DPRINTF("%s: Read error %d\n", __func__, error);
                        break;
                }

                size_t read_bytes = to_copy - auio.uio_resid;
                if (read_bytes == 0) {
                        /* EOF reached */
                        break;
                }

                /* Lock the output vnode for writing */
                vn_lock(fp_out->f_vnode, LK_EXCLUSIVE | LK_RETRY);
                /* Set up iovec and uio for writing */
                aiov.iov_base = buffer;
                aiov.iov_len = read_bytes;
                auio.uio_iov = &aiov;
                auio.uio_iovcnt = 1;
                auio.uio_offset = have_off_out ? off_out : fp_out->f_offset;
                auio.uio_resid = read_bytes;
                auio.uio_rw = UIO_WRITE;
                auio.uio_vmspace = l->l_proc->p_vmspace;
                UIO_SETUP_SYSSPACE(&auio);

                /* Perform the write */
                error = VOP_WRITE(fp_out->f_vnode, &auio, 0, l->l_cred);
                VOP_UNLOCK(fp_out->f_vnode);
                if (error) {
                        DPRINTF("%s: Write error %d\n", __func__, error);
                        break;
                }
                size_t written_bytes = read_bytes - auio.uio_resid;
                total_copied += written_bytes;
                bytes_left -= written_bytes;

                /* Update offsets if provided */
                if (have_off_in) {
                        off_in += written_bytes;
                } else {
                        fp_in->f_offset += written_bytes;
                }
                if (have_off_out) {
                        off_out += written_bytes;
                } else {
                        fp_out->f_offset += written_bytes;
                }
        }

        if (have_off_in) {
                /* Adjust user space offset */
                error = copyout(&off_in, SCARG(uap, off_in), sizeof(off_t));
                if (error) {
                        DPRINTF("%s: Error adjusting user space offset\n",
                            __func__);
                }
                goto out;
        }

        if (have_off_out) {
                /* Adjust user space offset */
                error = copyout(&off_out, SCARG(uap, off_out), sizeof(off_t));
                if (error) {
                        DPRINTF("%s: Error adjusting user space offset\n",
                            __func__);
                }
        }

        *retval = total_copied;
out:
        if (buffer) {
                kmem_free(buffer, LINUX_COPY_FILE_RANGE_MAX_CHUNK);
        }
        if (fp_out) {
                fd_putfile(fd_out);
        }
        if (fp_in) {
                fd_putfile(fd_in);
        }
        return error;
}

#define LINUX_NOT_SUPPORTED(fun) \
int \
fun(struct lwp *l, const struct fun##_args *uap, register_t *retval) \
{ \
        return EOPNOTSUPP; \
}

LINUX_NOT_SUPPORTED(linux_sys_setxattr)
LINUX_NOT_SUPPORTED(linux_sys_lsetxattr)
LINUX_NOT_SUPPORTED(linux_sys_fsetxattr)

LINUX_NOT_SUPPORTED(linux_sys_getxattr)
LINUX_NOT_SUPPORTED(linux_sys_lgetxattr)
LINUX_NOT_SUPPORTED(linux_sys_fgetxattr)

LINUX_NOT_SUPPORTED(linux_sys_listxattr)
LINUX_NOT_SUPPORTED(linux_sys_llistxattr)
LINUX_NOT_SUPPORTED(linux_sys_flistxattr)

LINUX_NOT_SUPPORTED(linux_sys_removexattr)
LINUX_NOT_SUPPORTED(linux_sys_lremovexattr)
LINUX_NOT_SUPPORTED(linux_sys_fremovexattr)

/*
 * For now just return EOPNOTSUPP, this makes glibc posix_fallocate()
 * to fallback to emulation.
 * XXX Right now no filesystem actually implements fallocate support,
 * so no need for mapping.
 */
LINUX_NOT_SUPPORTED(linux_sys_fallocate)