xnu-7195.50.7.100.1.tar.gz

[apple/xnu.git] / bsd / kern / sys_generic.c

/*
 * Copyright (c) 2000-2015 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 *
 *      @(#)sys_generic.c       8.9 (Berkeley) 2/14/95
 */
/*
 * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/file_internal.h>
#include <sys/proc_internal.h>
#include <sys/socketvar.h>
#include <sys/uio_internal.h>
#include <sys/kernel.h>
#include <sys/guarded.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/sysproto.h>

#include <sys/mount_internal.h>
#include <sys/protosw.h>
#include <sys/ev.h>
#include <sys/user.h>
#include <sys/kdebug.h>
#include <sys/poll.h>
#include <sys/event.h>
#include <sys/eventvar.h>
#include <sys/proc.h>
#include <sys/kauth.h>

#include <machine/smp.h>
#include <mach/mach_types.h>
#include <kern/kern_types.h>
#include <kern/assert.h>
#include <kern/kalloc.h>
#include <kern/thread.h>
#include <kern/clock.h>
#include <kern/ledger.h>
#include <kern/task.h>
#include <kern/telemetry.h>
#include <kern/waitq.h>
#include <kern/sched_prim.h>
#include <kern/mpsc_queue.h>
#include <kern/debug.h>

#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/syscall.h>
#include <sys/pipe.h>

#include <security/audit/audit.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/ip6.h>
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
#include <netinet/tcp_debug.h>
/* for wait queue based select */
#include <kern/waitq.h>
#include <sys/vnode_internal.h>
/* for remote time api*/
#include <kern/remote_time.h>
#include <os/log.h>
#include <sys/log_data.h>

#if CONFIG_MACF
#include <security/mac_framework.h>
#endif

/* for entitlement check */
#include <IOKit/IOBSD.h>

/* XXX should be in a header file somewhere */
extern kern_return_t IOBSDGetPlatformUUID(__darwin_uuid_t uuid, mach_timespec_t timeoutp);

int rd_uio(struct proc *p, int fdes, uio_t uio, int is_preadv, user_ssize_t *retval);
int wr_uio(struct proc *p, int fdes, uio_t uio, int is_pwritev, user_ssize_t *retval);
int do_uiowrite(struct proc *p, struct fileproc *fp, uio_t uio, int flags, user_ssize_t *retval);

__private_extern__ int  dofileread(vfs_context_t ctx, struct fileproc *fp,
    user_addr_t bufp, user_size_t nbyte,
    off_t offset, int flags, user_ssize_t *retval);
__private_extern__ int  dofilewrite(vfs_context_t ctx, struct fileproc *fp,
    user_addr_t bufp, user_size_t nbyte,
    off_t offset, int flags, user_ssize_t *retval);
static int preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_vnode);

/* Conflict wait queue for when selects collide (opaque type) */
struct waitq select_conflict_queue;

/*
 * Init routine called from bsd_init.c
 */
void select_waitq_init(void);
void
select_waitq_init(void)
{
        waitq_init(&select_conflict_queue, SYNC_POLICY_FIFO);
}

#define f_flag fp_glob->fg_flag
#define f_type fp_glob->fg_ops->fo_type
#define f_cred fp_glob->fg_cred
#define f_ops fp_glob->fg_ops
#define f_data fp_glob->fg_data

/*
 * Read system call.
 *
 * Returns:     0                       Success
 *      preparefileread:EBADF
 *      preparefileread:ESPIPE
 *      preparefileread:ENXIO
 *      preparefileread:EBADF
 *      dofileread:???
 */
int
read(struct proc *p, struct read_args *uap, user_ssize_t *retval)
{
        __pthread_testcancel(1);
        return read_nocancel(p, (struct read_nocancel_args *)uap, retval);
}

int
read_nocancel(struct proc *p, struct read_nocancel_args *uap, user_ssize_t *retval)
{
        struct fileproc *fp;
        int error;
        int fd = uap->fd;
        struct vfs_context context;

        if ((error = preparefileread(p, &fp, fd, 0))) {
                return error;
        }

        context = *(vfs_context_current());
        context.vc_ucred = fp->fp_glob->fg_cred;

        error = dofileread(&context, fp, uap->cbuf, uap->nbyte,
            (off_t)-1, 0, retval);

        fp_drop(p, fd, fp, 0);

        return error;
}

/*
 * Pread system call
 *
 * Returns:     0                       Success
 *      preparefileread:EBADF
 *      preparefileread:ESPIPE
 *      preparefileread:ENXIO
 *      preparefileread:EBADF
 *      dofileread:???
 */
int
pread(struct proc *p, struct pread_args *uap, user_ssize_t *retval)
{
        __pthread_testcancel(1);
        return pread_nocancel(p, (struct pread_nocancel_args *)uap, retval);
}

int
pread_nocancel(struct proc *p, struct pread_nocancel_args *uap, user_ssize_t *retval)
{
        struct fileproc *fp = NULL;     /* fp set by preparefileread() */
        int fd = uap->fd;
        int error;
        struct vfs_context context;

        if ((error = preparefileread(p, &fp, fd, 1))) {
                goto out;
        }

        context = *(vfs_context_current());
        context.vc_ucred = fp->fp_glob->fg_cred;

        error = dofileread(&context, fp, uap->buf, uap->nbyte,
            uap->offset, FOF_OFFSET, retval);

        fp_drop(p, fd, fp, 0);

        KERNEL_DEBUG_CONSTANT((BSDDBG_CODE(DBG_BSD_SC_EXTENDED_INFO, SYS_pread) | DBG_FUNC_NONE),
            uap->fd, uap->nbyte, (unsigned int)((uap->offset >> 32)), (unsigned int)(uap->offset), 0);

out:
        return error;
}

/*
 * Code common for read and pread
 */

/*
 * Returns:     0                       Success
 *              EBADF
 *              ESPIPE
 *              ENXIO
 *      fp_lookup:EBADF
 */
static int
preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_pread)
{
        vnode_t vp;
        int     error;
        struct fileproc *fp;

        AUDIT_ARG(fd, fd);

        proc_fdlock_spin(p);

        error = fp_lookup(p, fd, &fp, 1);

        if (error) {
                proc_fdunlock(p);
                return error;
        }
        if ((fp->f_flag & FREAD) == 0) {
                error = EBADF;
                goto out;
        }
        if (check_for_pread && (fp->f_type != DTYPE_VNODE)) {
                error = ESPIPE;
                goto out;
        }
        if (fp->f_type == DTYPE_VNODE) {
                vp = (struct vnode *)fp->fp_glob->fg_data;

                if (check_for_pread && (vnode_isfifo(vp))) {
                        error = ESPIPE;
                        goto out;
                }
                if (check_for_pread && (vp->v_flag & VISTTY)) {
                        error = ENXIO;
                        goto out;
                }
        }

        *fp_ret = fp;

        proc_fdunlock(p);
        return 0;

out:
        fp_drop(p, fd, fp, 1);
        proc_fdunlock(p);
        return error;
}


/*
 * Returns:     0                       Success
 *              EINVAL
 *      fo_read:???
 */
__private_extern__ int
dofileread(vfs_context_t ctx, struct fileproc *fp,
    user_addr_t bufp, user_size_t nbyte, off_t offset, int flags,
    user_ssize_t *retval)
{
        uio_t auio;
        user_ssize_t bytecnt;
        int error = 0;
        char uio_buf[UIO_SIZEOF(1)];

        if (nbyte > INT_MAX) {
                return EINVAL;
        }

        if (IS_64BIT_PROCESS(vfs_context_proc(ctx))) {
                auio = uio_createwithbuffer(1, offset, UIO_USERSPACE64, UIO_READ,
                    &uio_buf[0], sizeof(uio_buf));
        } else {
                auio = uio_createwithbuffer(1, offset, UIO_USERSPACE32, UIO_READ,
                    &uio_buf[0], sizeof(uio_buf));
        }
        if (uio_addiov(auio, bufp, nbyte) != 0) {
                *retval = 0;
                return EINVAL;
        }

        bytecnt = nbyte;

        if ((error = fo_read(fp, auio, flags, ctx))) {
                if (uio_resid(auio) != bytecnt && (error == ERESTART ||
                    error == EINTR || error == EWOULDBLOCK)) {
                        error = 0;
                }
        }
        bytecnt -= uio_resid(auio);

        *retval = bytecnt;

        return error;
}

/*
 * Vector read.
 *
 * Returns:    0                       Success
 *             EINVAL
 *             ENOMEM
 *     preparefileread:EBADF
 *     preparefileread:ESPIPE
 *     preparefileread:ENXIO
 *     preparefileread:EBADF
 *     copyin:EFAULT
 *     rd_uio:???
 */
static int
readv_preadv_uio(struct proc *p, int fdes,
    user_addr_t user_iovp, int iovcnt, off_t offset, int is_preadv,
    user_ssize_t *retval)
{
        uio_t auio = NULL;
        int error;
        struct user_iovec *iovp;

        /* Verify range before calling uio_create() */
        if (iovcnt <= 0 || iovcnt > UIO_MAXIOV) {
                return EINVAL;
        }

        /* allocate a uio large enough to hold the number of iovecs passed */
        auio = uio_create(iovcnt, offset,
            (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
            UIO_READ);

        /* get location of iovecs within the uio.  then copyin the iovecs from
         * user space.
         */
        iovp = uio_iovsaddr(auio);
        if (iovp == NULL) {
                error = ENOMEM;
                goto ExitThisRoutine;
        }
        error = copyin_user_iovec_array(user_iovp,
            IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32,
            iovcnt, iovp);
        if (error) {
                goto ExitThisRoutine;
        }

        /* finalize uio_t for use and do the IO
         */
        error = uio_calculateresid(auio);
        if (error) {
                goto ExitThisRoutine;
        }
        error = rd_uio(p, fdes, auio, is_preadv, retval);

ExitThisRoutine:
        if (auio != NULL) {
                uio_free(auio);
        }
        return error;
}

/*
 * Scatter read system call.
 */
int
readv(struct proc *p, struct readv_args *uap, user_ssize_t *retval)
{
        __pthread_testcancel(1);
        return readv_nocancel(p, (struct readv_nocancel_args *)uap, retval);
}

int
readv_nocancel(struct proc *p, struct readv_nocancel_args *uap, user_ssize_t *retval)
{
        return readv_preadv_uio(p, uap->fd, uap->iovp, uap->iovcnt, 0, 0, retval);
}

/*
 * Preadv system call
 */
int
sys_preadv(struct proc *p, struct preadv_args *uap, user_ssize_t *retval)
{
        __pthread_testcancel(1);
        return sys_preadv_nocancel(p, (struct preadv_nocancel_args *)uap, retval);
}

int
sys_preadv_nocancel(struct proc *p, struct preadv_nocancel_args *uap, user_ssize_t *retval)
{
        return readv_preadv_uio(p, uap->fd, uap->iovp, uap->iovcnt, uap->offset, 1, retval);
}

/*
 * Write system call
 *
 * Returns:     0                       Success
 *              EBADF
 *      fp_lookup:EBADF
 *      dofilewrite:???
 */
int
write(struct proc *p, struct write_args *uap, user_ssize_t *retval)
{
        __pthread_testcancel(1);
        return write_nocancel(p, (struct write_nocancel_args *)uap, retval);
}

int
write_nocancel(struct proc *p, struct write_nocancel_args *uap, user_ssize_t *retval)
{
        struct fileproc *fp;
        int error;
        int fd = uap->fd;

        AUDIT_ARG(fd, fd);

        error = fp_lookup(p, fd, &fp, 0);
        if (error) {
                return error;
        }
        if ((fp->f_flag & FWRITE) == 0) {
                error = EBADF;
        } else if (FP_ISGUARDED(fp, GUARD_WRITE)) {
                proc_fdlock(p);
                error = fp_guard_exception(p, fd, fp, kGUARD_EXC_WRITE);
                proc_fdunlock(p);
        } else {
                struct vfs_context context = *(vfs_context_current());
                context.vc_ucred = fp->fp_glob->fg_cred;

                error = dofilewrite(&context, fp, uap->cbuf, uap->nbyte,
                    (off_t)-1, 0, retval);
        }
        fp_drop(p, fd, fp, 0);
        return error;
}

/*
 * pwrite system call
 *
 * Returns:     0                       Success
 *              EBADF
 *              ESPIPE
 *              ENXIO
 *              EINVAL
 *      fp_lookup:EBADF
 *      dofilewrite:???
 */
int
pwrite(struct proc *p, struct pwrite_args *uap, user_ssize_t *retval)
{
        __pthread_testcancel(1);
        return pwrite_nocancel(p, (struct pwrite_nocancel_args *)uap, retval);
}

int
pwrite_nocancel(struct proc *p, struct pwrite_nocancel_args *uap, user_ssize_t *retval)
{
        struct fileproc *fp;
        int error;
        int fd = uap->fd;
        vnode_t vp  = (vnode_t)0;

        AUDIT_ARG(fd, fd);

        error = fp_get_ftype(p, fd, DTYPE_VNODE, ESPIPE, &fp);
        if (error) {
                return error;
        }

        if ((fp->f_flag & FWRITE) == 0) {
                error = EBADF;
        } else if (FP_ISGUARDED(fp, GUARD_WRITE)) {
                proc_fdlock(p);
                error = fp_guard_exception(p, fd, fp, kGUARD_EXC_WRITE);
                proc_fdunlock(p);
        } else {
                struct vfs_context context = *vfs_context_current();
                context.vc_ucred = fp->fp_glob->fg_cred;

                vp = (vnode_t)fp->fp_glob->fg_data;
                if (vnode_isfifo(vp)) {
                        error = ESPIPE;
                        goto errout;
                }
                if ((vp->v_flag & VISTTY)) {
                        error = ENXIO;
                        goto errout;
                }
                if (uap->offset == (off_t)-1) {
                        error = EINVAL;
                        goto errout;
                }

                error = dofilewrite(&context, fp, uap->buf, uap->nbyte,
                    uap->offset, FOF_OFFSET, retval);
        }
errout:
        fp_drop(p, fd, fp, 0);

        KERNEL_DEBUG_CONSTANT((BSDDBG_CODE(DBG_BSD_SC_EXTENDED_INFO, SYS_pwrite) | DBG_FUNC_NONE),
            uap->fd, uap->nbyte, (unsigned int)((uap->offset >> 32)), (unsigned int)(uap->offset), 0);

        return error;
}

/*
 * Returns:     0                       Success
 *              EINVAL
 *      <fo_write>:EPIPE
 *      <fo_write>:???                  [indirect through struct fileops]
 */
__private_extern__ int
dofilewrite(vfs_context_t ctx, struct fileproc *fp,
    user_addr_t bufp, user_size_t nbyte, off_t offset, int flags,
    user_ssize_t *retval)
{
        uio_t auio;
        int error = 0;
        user_ssize_t bytecnt;
        char uio_buf[UIO_SIZEOF(1)];

        if (nbyte > INT_MAX) {
                *retval = 0;
                return EINVAL;
        }

        if (IS_64BIT_PROCESS(vfs_context_proc(ctx))) {
                auio = uio_createwithbuffer(1, offset, UIO_USERSPACE64, UIO_WRITE,
                    &uio_buf[0], sizeof(uio_buf));
        } else {
                auio = uio_createwithbuffer(1, offset, UIO_USERSPACE32, UIO_WRITE,
                    &uio_buf[0], sizeof(uio_buf));
        }
        if (uio_addiov(auio, bufp, nbyte) != 0) {
                *retval = 0;
                return EINVAL;
        }

        bytecnt = nbyte;
        if ((error = fo_write(fp, auio, flags, ctx))) {
                if (uio_resid(auio) != bytecnt && (error == ERESTART ||
                    error == EINTR || error == EWOULDBLOCK)) {
                        error = 0;
                }
                /* The socket layer handles SIGPIPE */
                if (error == EPIPE && fp->f_type != DTYPE_SOCKET &&
                    (fp->fp_glob->fg_lflags & FG_NOSIGPIPE) == 0) {
                        /* XXX Raise the signal on the thread? */
                        psignal(vfs_context_proc(ctx), SIGPIPE);
                }
        }
        bytecnt -= uio_resid(auio);
        if (bytecnt) {
                os_atomic_or(&fp->fp_glob->fg_flag, FWASWRITTEN, relaxed);
        }
        *retval = bytecnt;

        return error;
}

/*
 * Returns:     0                       Success
 *              EBADF
 *              ESPIPE
 *              ENXIO
 *      fp_lookup:EBADF
 *      fp_guard_exception:???
 */
static int
preparefilewrite(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_pwrite)
{
        vnode_t vp;
        int error;
        struct fileproc *fp;

        AUDIT_ARG(fd, fd);

        proc_fdlock_spin(p);

        error = fp_lookup(p, fd, &fp, 1);

        if (error) {
                proc_fdunlock(p);
                return error;
        }
        if ((fp->f_flag & FWRITE) == 0) {
                error = EBADF;
                goto ExitThisRoutine;
        }
        if (FP_ISGUARDED(fp, GUARD_WRITE)) {
                error = fp_guard_exception(p, fd, fp, kGUARD_EXC_WRITE);
                goto ExitThisRoutine;
        }
        if (check_for_pwrite) {
                if (fp->f_type != DTYPE_VNODE) {
                        error = ESPIPE;
                        goto ExitThisRoutine;
                }

                vp = (vnode_t)fp->fp_glob->fg_data;
                if (vnode_isfifo(vp)) {
                        error = ESPIPE;
                        goto ExitThisRoutine;
                }
                if ((vp->v_flag & VISTTY)) {
                        error = ENXIO;
                        goto ExitThisRoutine;
                }
        }

        *fp_ret = fp;

        proc_fdunlock(p);
        return 0;

ExitThisRoutine:
        fp_drop(p, fd, fp, 1);
        proc_fdunlock(p);
        return error;
}

static int
writev_prwritev_uio(struct proc *p, int fd,
    user_addr_t user_iovp, int iovcnt, off_t offset, int is_pwritev,
    user_ssize_t *retval)
{
        uio_t auio = NULL;
        int error;
        struct user_iovec *iovp;

        /* Verify range before calling uio_create() */
        if (iovcnt <= 0 || iovcnt > UIO_MAXIOV || offset < 0) {
                return EINVAL;
        }

        /* allocate a uio large enough to hold the number of iovecs passed */
        auio = uio_create(iovcnt, offset,
            (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
            UIO_WRITE);

        /* get location of iovecs within the uio.  then copyin the iovecs from
         * user space.
         */
        iovp = uio_iovsaddr(auio);
        if (iovp == NULL) {
                error = ENOMEM;
                goto ExitThisRoutine;
        }
        error = copyin_user_iovec_array(user_iovp,
            IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32,
            iovcnt, iovp);
        if (error) {
                goto ExitThisRoutine;
        }

        /* finalize uio_t for use and do the IO
         */
        error = uio_calculateresid(auio);
        if (error) {
                goto ExitThisRoutine;
        }

        error = wr_uio(p, fd, auio, is_pwritev, retval);

ExitThisRoutine:
        if (auio != NULL) {
                uio_free(auio);
        }
        return error;
}

/*
 * Gather write system call
 */
int
writev(struct proc *p, struct writev_args *uap, user_ssize_t *retval)
{
        __pthread_testcancel(1);
        return writev_nocancel(p, (struct writev_nocancel_args *)uap, retval);
}

int
writev_nocancel(struct proc *p, struct writev_nocancel_args *uap, user_ssize_t *retval)
{
        return writev_prwritev_uio(p, uap->fd, uap->iovp, uap->iovcnt, 0, 0, retval);
}

/*
 * Pwritev system call
 */
int
sys_pwritev(struct proc *p, struct pwritev_args *uap, user_ssize_t *retval)
{
        __pthread_testcancel(1);
        return sys_pwritev_nocancel(p, (struct pwritev_nocancel_args *)uap, retval);
}

int
sys_pwritev_nocancel(struct proc *p, struct pwritev_nocancel_args *uap, user_ssize_t *retval)
{
        return writev_prwritev_uio(p, uap->fd, uap->iovp, uap->iovcnt, uap->offset, 1, retval);
}

/*
 * Returns:     0                       Success
 *      preparefileread:EBADF
 *      preparefileread:ESPIPE
 *      preparefileread:ENXIO
 *      preparefileread:???
 *      fo_write:???
 */
int
wr_uio(struct proc *p, int fd, uio_t uio, int is_pwritev, user_ssize_t *retval)
{
        struct fileproc *fp;
        int error;
        int flags;

        if ((error = preparefilewrite(p, &fp, fd, is_pwritev))) {
                return error;
        }

        flags = is_pwritev ? FOF_OFFSET : 0;
        error = do_uiowrite(p, fp, uio, flags, retval);

        fp_drop(p, fd, fp, 0);

        return error;
}

int
do_uiowrite(struct proc *p, struct fileproc *fp, uio_t uio, int flags, user_ssize_t *retval)
{
        int error;
        user_ssize_t count;
        struct vfs_context context = *vfs_context_current();

        count = uio_resid(uio);

        context.vc_ucred = fp->f_cred;
        error = fo_write(fp, uio, flags, &context);
        if (error) {
                if (uio_resid(uio) != count && (error == ERESTART ||
                    error == EINTR || error == EWOULDBLOCK)) {
                        error = 0;
                }
                /* The socket layer handles SIGPIPE */
                if (error == EPIPE && fp->f_type != DTYPE_SOCKET &&
                    (fp->fp_glob->fg_lflags & FG_NOSIGPIPE) == 0) {
                        psignal(p, SIGPIPE);
                }
        }
        count -= uio_resid(uio);
        if (count) {
                os_atomic_or(&fp->fp_glob->fg_flag, FWASWRITTEN, relaxed);
        }
        *retval = count;

        return error;
}

/*
 * Returns:     0                       Success
 *      preparefileread:EBADF
 *      preparefileread:ESPIPE
 *      preparefileread:ENXIO
 *      fo_read:???
 */
int
rd_uio(struct proc *p, int fdes, uio_t uio, int is_preadv, user_ssize_t *retval)
{
        struct fileproc *fp;
        int error;
        user_ssize_t count;
        struct vfs_context context = *vfs_context_current();

        if ((error = preparefileread(p, &fp, fdes, is_preadv))) {
                return error;
        }

        count = uio_resid(uio);

        context.vc_ucred = fp->f_cred;

        int flags = is_preadv ? FOF_OFFSET : 0;
        error = fo_read(fp, uio, flags, &context);

        if (error) {
                if (uio_resid(uio) != count && (error == ERESTART ||
                    error == EINTR || error == EWOULDBLOCK)) {
                        error = 0;
                }
        }
        *retval = count - uio_resid(uio);

        fp_drop(p, fdes, fp, 0);

        return error;
}

/*
 * Ioctl system call
 *
 * Returns:     0                       Success
 *              EBADF
 *              ENOTTY
 *              ENOMEM
 *              ESRCH
 *      copyin:EFAULT
 *      copyoutEFAULT
 *      fp_lookup:EBADF                 Bad file descriptor
 *      fo_ioctl:???
 */
int
ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
{
        struct fileproc *fp = NULL;
        int error = 0;
        u_int size = 0;
        caddr_t datap = NULL, memp = NULL;
        boolean_t is64bit = FALSE;
        int tmp = 0;
#define STK_PARAMS      128
        char stkbuf[STK_PARAMS] = {};
        int fd = uap->fd;
        u_long com = uap->com;
        struct vfs_context context = *vfs_context_current();

        AUDIT_ARG(fd, uap->fd);
        AUDIT_ARG(addr, uap->data);

        is64bit = proc_is64bit(p);
#if CONFIG_AUDIT
        if (is64bit) {
                AUDIT_ARG(value64, com);
        } else {
                AUDIT_ARG(cmd, CAST_DOWN_EXPLICIT(int, com));
        }
#endif /* CONFIG_AUDIT */

        /*
         * Interpret high order word to find amount of data to be
         * copied to/from the user's address space.
         */
        size = IOCPARM_LEN(com);
        if (size > IOCPARM_MAX) {
                return ENOTTY;
        }
        if (size > sizeof(stkbuf)) {
                memp = (caddr_t)kheap_alloc(KHEAP_TEMP, size, Z_WAITOK);
                if (memp == 0) {
                        return ENOMEM;
                }
                datap = memp;
        } else {
                datap = &stkbuf[0];
        }
        if (com & IOC_IN) {
                if (size) {
                        error = copyin(uap->data, datap, size);
                        if (error) {
                                goto out_nofp;
                        }
                } else {
                        /* XXX - IOC_IN and no size?  we should proably return an error here!! */
                        if (is64bit) {
                                *(user_addr_t *)datap = uap->data;
                        } else {
                                *(uint32_t *)datap = (uint32_t)uap->data;
                        }
                }
        } else if ((com & IOC_OUT) && size) {
                /*
                 * Zero the buffer so the user always
                 * gets back something deterministic.
                 */
                bzero(datap, size);
        } else if (com & IOC_VOID) {
                /* XXX - this is odd since IOC_VOID means no parameters */
                if (is64bit) {
                        *(user_addr_t *)datap = uap->data;
                } else {
                        *(uint32_t *)datap = (uint32_t)uap->data;
                }
        }

        proc_fdlock(p);
        error = fp_lookup(p, fd, &fp, 1);
        if (error) {
                proc_fdunlock(p);
                goto out_nofp;
        }

        AUDIT_ARG(file, p, fp);

        if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
                error = EBADF;
                goto out;
        }

        context.vc_ucred = fp->fp_glob->fg_cred;

#if CONFIG_MACF
        error = mac_file_check_ioctl(context.vc_ucred, fp->fp_glob, com);
        if (error) {
                goto out;
        }
#endif

        switch (com) {
        case FIONCLEX:
                *fdflags(p, fd) &= ~UF_EXCLOSE;
                break;

        case FIOCLEX:
                *fdflags(p, fd) |= UF_EXCLOSE;
                break;

        case FIONBIO:
                // FIXME (rdar://54898652)
                //
                // this code is broken if fnctl(F_SETFL), ioctl() are
                // called concurrently for the same fileglob.
                if ((tmp = *(int *)datap)) {
                        os_atomic_or(&fp->f_flag, FNONBLOCK, relaxed);
                } else {
                        os_atomic_andnot(&fp->f_flag, FNONBLOCK, relaxed);
                }
                error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, &context);
                break;

        case FIOASYNC:
                // FIXME (rdar://54898652)
                //
                // this code is broken if fnctl(F_SETFL), ioctl() are
                // called concurrently for the same fileglob.
                if ((tmp = *(int *)datap)) {
                        os_atomic_or(&fp->f_flag, FASYNC, relaxed);
                } else {
                        os_atomic_andnot(&fp->f_flag, FASYNC, relaxed);
                }
                error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, &context);
                break;

        case FIOSETOWN:
                tmp = *(int *)datap;
                if (fp->f_type == DTYPE_SOCKET) {
                        ((struct socket *)fp->f_data)->so_pgid = tmp;
                        break;
                }
                if (fp->f_type == DTYPE_PIPE) {
                        error = fo_ioctl(fp, TIOCSPGRP, (caddr_t)&tmp, &context);
                        break;
                }
                if (tmp <= 0) {
                        tmp = -tmp;
                } else {
                        struct proc *p1 = proc_find(tmp);
                        if (p1 == 0) {
                                error = ESRCH;
                                break;
                        }
                        tmp = p1->p_pgrpid;
                        proc_rele(p1);
                }
                error = fo_ioctl(fp, TIOCSPGRP, (caddr_t)&tmp, &context);
                break;

        case FIOGETOWN:
                if (fp->f_type == DTYPE_SOCKET) {
                        *(int *)datap = ((struct socket *)fp->f_data)->so_pgid;
                        break;
                }
                error = fo_ioctl(fp, TIOCGPGRP, datap, &context);
                *(int *)datap = -*(int *)datap;
                break;

        default:
                error = fo_ioctl(fp, com, datap, &context);
                /*
                 * Copy any data to user, size was
                 * already set and checked above.
                 */
                if (error == 0 && (com & IOC_OUT) && size) {
                        error = copyout(datap, uap->data, (u_int)size);
                }
                break;
        }
out:
        fp_drop(p, fd, fp, 1);
        proc_fdunlock(p);

out_nofp:
        if (memp) {
                kheap_free(KHEAP_TEMP, memp, size);
        }
        return error;
}

int     selwait, nselcoll;
#define SEL_FIRSTPASS 1
#define SEL_SECONDPASS 2
extern int selcontinue(int error);
extern int selprocess(int error, int sel_pass);
static int selscan(struct proc *p, struct _select * sel, struct _select_data * seldata,
    int nfd, int32_t *retval, int sel_pass, struct waitq_set *wqset);
static int selcount(struct proc *p, u_int32_t *ibits, int nfd, int *count);
static int seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wakeup);
static int seldrop(struct proc *p, u_int32_t *ibits, int nfd, int lim);
static int select_internal(struct proc *p, struct select_nocancel_args *uap, uint64_t timeout, int32_t *retval);

/*
 * Select system call.
 *
 * Returns:     0                       Success
 *              EINVAL                  Invalid argument
 *              EAGAIN                  Nonconformant error if allocation fails
 */
int
select(struct proc *p, struct select_args *uap, int32_t *retval)
{
        __pthread_testcancel(1);
        return select_nocancel(p, (struct select_nocancel_args *)uap, retval);
}

int
select_nocancel(struct proc *p, struct select_nocancel_args *uap, int32_t *retval)
{
        uint64_t timeout = 0;

        if (uap->tv) {
                int err;
                struct timeval atv;
                if (IS_64BIT_PROCESS(p)) {
                        struct user64_timeval atv64;
                        err = copyin(uap->tv, (caddr_t)&atv64, sizeof(atv64));
                        /* Loses resolution - assume timeout < 68 years */
                        atv.tv_sec = (__darwin_time_t)atv64.tv_sec;
                        atv.tv_usec = atv64.tv_usec;
                } else {
                        struct user32_timeval atv32;
                        err = copyin(uap->tv, (caddr_t)&atv32, sizeof(atv32));
                        atv.tv_sec = atv32.tv_sec;
                        atv.tv_usec = atv32.tv_usec;
                }
                if (err) {
                        return err;
                }

                if (itimerfix(&atv)) {
                        err = EINVAL;
                        return err;
                }

                clock_absolutetime_interval_to_deadline(tvtoabstime(&atv), &timeout);
        }

        return select_internal(p, uap, timeout, retval);
}

int
pselect(struct proc *p, struct pselect_args *uap, int32_t *retval)
{
        __pthread_testcancel(1);
        return pselect_nocancel(p, (struct pselect_nocancel_args *)uap, retval);
}

int
pselect_nocancel(struct proc *p, struct pselect_nocancel_args *uap, int32_t *retval)
{
        int err;
        struct uthread *ut;
        uint64_t timeout = 0;

        if (uap->ts) {
                struct timespec ts;

                if (IS_64BIT_PROCESS(p)) {
                        struct user64_timespec ts64;
                        err = copyin(uap->ts, (caddr_t)&ts64, sizeof(ts64));
                        ts.tv_sec = (__darwin_time_t)ts64.tv_sec;
                        ts.tv_nsec = (long)ts64.tv_nsec;
                } else {
                        struct user32_timespec ts32;
                        err = copyin(uap->ts, (caddr_t)&ts32, sizeof(ts32));
                        ts.tv_sec = ts32.tv_sec;
                        ts.tv_nsec = ts32.tv_nsec;
                }
                if (err) {
                        return err;
                }

                if (!timespec_is_valid(&ts)) {
                        return EINVAL;
                }
                clock_absolutetime_interval_to_deadline(tstoabstime(&ts), &timeout);
        }

        ut = get_bsdthread_info(current_thread());

        if (uap->mask != USER_ADDR_NULL) {
                /* save current mask, then copyin and set new mask */
                sigset_t newset;
                err = copyin(uap->mask, &newset, sizeof(sigset_t));
                if (err) {
                        return err;
                }
                ut->uu_oldmask = ut->uu_sigmask;
                ut->uu_flag |= UT_SAS_OLDMASK;
                ut->uu_sigmask = (newset & ~sigcantmask);
        }

        err = select_internal(p, (struct select_nocancel_args *)uap, timeout, retval);

        if (err != EINTR && ut->uu_flag & UT_SAS_OLDMASK) {
                /*
                 * Restore old mask (direct return case). NOTE: EINTR can also be returned
                 * if the thread is cancelled. In that case, we don't reset the signal
                 * mask to its original value (which usually happens in the signal
                 * delivery path). This behavior is permitted by POSIX.
                 */
                ut->uu_sigmask = ut->uu_oldmask;
                ut->uu_oldmask = 0;
                ut->uu_flag &= ~UT_SAS_OLDMASK;
        }

        return err;
}

/*
 * Generic implementation of {,p}select. Care: we type-pun uap across the two
 * syscalls, which differ slightly. The first 4 arguments (nfds and the fd sets)
 * are identical. The 5th (timeout) argument points to different types, so we
 * unpack in the syscall-specific code, but the generic code still does a null
 * check on this argument to determine if a timeout was specified.
 */
static int
select_internal(struct proc *p, struct select_nocancel_args *uap, uint64_t timeout, int32_t *retval)
{
        int error = 0;
        u_int ni, nw;
        thread_t th_act;
        struct uthread  *uth;
        struct _select *sel;
        struct _select_data *seldata;
        int needzerofill = 1;
        int count = 0;
        size_t sz = 0;

        th_act = current_thread();
        uth = get_bsdthread_info(th_act);
        sel = &uth->uu_select;
        seldata = &uth->uu_save.uus_select_data;
        *retval = 0;

        seldata->args = uap;
        seldata->retval = retval;
        seldata->wqp = NULL;
        seldata->count = 0;

        if (uap->nd < 0) {
                return EINVAL;
        }

        /* select on thread of process that already called proc_exit() */
        if (p->p_fd == NULL) {
                return EBADF;
        }

        if (uap->nd > p->p_fd->fd_nfiles) {
                uap->nd = p->p_fd->fd_nfiles; /* forgiving; slightly wrong */
        }
        nw = howmany(uap->nd, NFDBITS);
        ni = nw * sizeof(fd_mask);

        /*
         * if the previously allocated space for the bits is smaller than
         * what is requested or no space has yet been allocated for this
         * thread, allocate enough space now.
         *
         * Note: If this process fails, select() will return EAGAIN; this
         * is the same thing pool() returns in a no-memory situation, but
         * it is not a POSIX compliant error code for select().
         */
        if (sel->nbytes < (3 * ni)) {
                int nbytes = 3 * ni;

                /* Free previous allocation, if any */
                if (sel->ibits != NULL) {
                        FREE(sel->ibits, M_TEMP);
                }
                if (sel->obits != NULL) {
                        FREE(sel->obits, M_TEMP);
                        /* NULL out; subsequent ibits allocation may fail */
                        sel->obits = NULL;
                }

                MALLOC(sel->ibits, u_int32_t *, nbytes, M_TEMP, M_WAITOK | M_ZERO);
                if (sel->ibits == NULL) {
                        return EAGAIN;
                }
                MALLOC(sel->obits, u_int32_t *, nbytes, M_TEMP, M_WAITOK | M_ZERO);
                if (sel->obits == NULL) {
                        FREE(sel->ibits, M_TEMP);
                        sel->ibits = NULL;
                        return EAGAIN;
                }
                sel->nbytes = nbytes;
                needzerofill = 0;
        }

        if (needzerofill) {
                bzero((caddr_t)sel->ibits, sel->nbytes);
                bzero((caddr_t)sel->obits, sel->nbytes);
        }

        /*
         * get the bits from the user address space
         */
#define getbits(name, x) \
        do { \
                if (uap->name && (error = copyin(uap->name, \
                        (caddr_t)&sel->ibits[(x) * nw], ni))) \
                        goto continuation; \
        } while (0)

        getbits(in, 0);
        getbits(ou, 1);
        getbits(ex, 2);
#undef  getbits

        seldata->abstime = timeout;

        if ((error = selcount(p, sel->ibits, uap->nd, &count))) {
                goto continuation;
        }

        /*
         * We need an array of waitq pointers. This is due to the new way
         * in which waitqs are linked to sets. When a thread selects on a
         * file descriptor, a waitq (embedded in a selinfo structure) is
         * added to the thread's local waitq set. There is no longer any
         * way to directly iterate over all members of a given waitq set.
         * The process of linking a waitq into a set may allocate a link
         * table object. Because we can't iterate over all the waitqs to
         * which our thread waitq set belongs, we need a way of removing
         * this link object!
         *
         * Thus we need a buffer which will hold one waitq pointer
         * per FD being selected. During the tear-down phase we can use
         * these pointers to dis-associate the underlying selinfo's waitq
         * from our thread's waitq set.
         *
         * Because we also need to allocate a waitq set for this thread,
         * we use a bare buffer pointer to hold all the memory. Note that
         * this memory is cached in the thread pointer and not reaped until
         * the thread exists. This is generally OK because threads that
         * call select tend to keep calling select repeatedly.
         */
        sz = ALIGN(sizeof(struct waitq_set)) + (count * sizeof(uint64_t));
        if (sz > uth->uu_wqstate_sz) {
                /* (re)allocate a buffer to hold waitq pointers */
                if (uth->uu_wqset) {
                        if (waitq_set_is_valid(uth->uu_wqset)) {
                                waitq_set_deinit(uth->uu_wqset);
                        }
                        FREE(uth->uu_wqset, M_SELECT);
                } else if (uth->uu_wqstate_sz && !uth->uu_wqset) {
                        panic("select: thread structure corrupt! "
                            "uu_wqstate_sz:%ld, wqstate_buf == NULL",
                            uth->uu_wqstate_sz);
                }
                uth->uu_wqstate_sz = sz;
                MALLOC(uth->uu_wqset, struct waitq_set *, sz, M_SELECT, M_WAITOK);
                if (!uth->uu_wqset) {
                        panic("can't allocate %ld bytes for wqstate buffer",
                            uth->uu_wqstate_sz);
                }
                waitq_set_init(uth->uu_wqset,
                    SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST, NULL, NULL);
        }

        if (!waitq_set_is_valid(uth->uu_wqset)) {
                waitq_set_init(uth->uu_wqset,
                    SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST, NULL, NULL);
        }

        /* the last chunk of our buffer is an array of waitq pointers */
        seldata->wqp = (uint64_t *)((char *)(uth->uu_wqset) + ALIGN(sizeof(struct waitq_set)));
        bzero(seldata->wqp, sz - ALIGN(sizeof(struct waitq_set)));

        seldata->count = count;

continuation:

        if (error) {
                /*
                 * We have already cleaned up any state we established,
                 * either locally or as a result of selcount().  We don't
                 * need to wait_subqueue_unlink_all(), since we haven't set
                 * anything at this point.
                 */
                return error;
        }

        return selprocess(0, SEL_FIRSTPASS);
}

int
selcontinue(int error)
{
        return selprocess(error, SEL_SECONDPASS);
}


/*
 * selprocess
 *
 * Parameters:  error                   The error code from our caller
 *              sel_pass                The pass we are on
 */
int
selprocess(int error, int sel_pass)
{
        int ncoll;
        u_int ni, nw;
        thread_t th_act;
        struct uthread  *uth;
        struct proc *p;
        struct select_nocancel_args *uap;
        int *retval;
        struct _select *sel;
        struct _select_data *seldata;
        int unwind = 1;
        int prepost = 0;
        int somewakeup = 0;
        int doretry = 0;
        wait_result_t wait_result;

        p = current_proc();
        th_act = current_thread();
        uth = get_bsdthread_info(th_act);
        sel = &uth->uu_select;
        seldata = &uth->uu_save.uus_select_data;
        uap = seldata->args;
        retval = seldata->retval;

        if ((error != 0) && (sel_pass == SEL_FIRSTPASS)) {
                unwind = 0;
        }
        if (seldata->count == 0) {
                unwind = 0;
        }
retry:
        if (error != 0) {
                goto done;
        }

        ncoll = nselcoll;
        OSBitOrAtomic(P_SELECT, &p->p_flag);

        /* skip scans if the select is just for timeouts */
        if (seldata->count) {
                error = selscan(p, sel, seldata, uap->nd, retval, sel_pass, uth->uu_wqset);
                if (error || *retval) {
                        goto done;
                }
                if (prepost || somewakeup) {
                        /*
                         * if the select of log, then we can wakeup and
                         * discover some one else already read the data;
                         * go to select again if time permits
                         */
                        prepost = 0;
                        somewakeup = 0;
                        doretry = 1;
                }
        }

        if (uap->tv) {
                uint64_t        now;

                clock_get_uptime(&now);
                if (now >= seldata->abstime) {
                        goto done;
                }
        }

        if (doretry) {
                /* cleanup obits and try again */
                doretry = 0;
                sel_pass = SEL_FIRSTPASS;
                goto retry;
        }

        /*
         * To effect a poll, the timeout argument should be
         * non-nil, pointing to a zero-valued timeval structure.
         */
        if (uap->tv && seldata->abstime == 0) {
                goto done;
        }

        /* No spurious wakeups due to colls,no need to check for them */
        if ((sel_pass == SEL_SECONDPASS) || ((p->p_flag & P_SELECT) == 0)) {
                sel_pass = SEL_FIRSTPASS;
                goto retry;
        }

        OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);

        /* if the select is just for timeout skip check */
        if (seldata->count && (sel_pass == SEL_SECONDPASS)) {
                panic("selprocess: 2nd pass assertwaiting");
        }

        /* waitq_set has waitqueue as first element */
        wait_result = waitq_assert_wait64_leeway((struct waitq *)uth->uu_wqset,
            NO_EVENT64, THREAD_ABORTSAFE,
            TIMEOUT_URGENCY_USER_NORMAL,
            seldata->abstime,
            TIMEOUT_NO_LEEWAY);
        if (wait_result != THREAD_AWAKENED) {
                /* there are no preposted events */
                error = tsleep1(NULL, PSOCK | PCATCH,
                    "select", 0, selcontinue);
        } else {
                prepost = 1;
                error = 0;
        }

        if (error == 0) {
                sel_pass = SEL_SECONDPASS;
                if (!prepost) {
                        somewakeup = 1;
                }
                goto retry;
        }
done:
        if (unwind) {
                seldrop(p, sel->ibits, uap->nd, seldata->count);
                waitq_set_deinit(uth->uu_wqset);
                /*
                 * zero out the waitq pointer array to avoid use-after free
                 * errors in the selcount error path (seldrop_locked) if/when
                 * the thread re-calls select().
                 */
                bzero((void *)uth->uu_wqset, uth->uu_wqstate_sz);
        }
        OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);
        /* select is not restarted after signals... */
        if (error == ERESTART) {
                error = EINTR;
        }
        if (error == EWOULDBLOCK) {
                error = 0;
        }
        nw = howmany(uap->nd, NFDBITS);
        ni = nw * sizeof(fd_mask);

#define putbits(name, x) \
        do { \
                if (uap->name && (error2 = \
                        copyout((caddr_t)&sel->obits[(x) * nw], uap->name, ni))) \
                        error = error2; \
        } while (0)

        if (error == 0) {
                int error2;

                putbits(in, 0);
                putbits(ou, 1);
                putbits(ex, 2);
#undef putbits
        }

        if (error != EINTR && sel_pass == SEL_SECONDPASS && uth->uu_flag & UT_SAS_OLDMASK) {
                /* restore signal mask - continuation case */
                uth->uu_sigmask = uth->uu_oldmask;
                uth->uu_oldmask = 0;
                uth->uu_flag &= ~UT_SAS_OLDMASK;
        }

        return error;
}


/**
 * remove the fileproc's underlying waitq from the supplied waitq set;
 * clear FP_INSELECT when appropriate
 *
 * Parameters:
 *              fp      File proc that is potentially currently in select
 *              wqset   Waitq set to which the fileproc may belong
 *                      (usually this is the thread's private waitq set)
 * Conditions:
 *              proc_fdlock is held
 */
static void
selunlinkfp(struct fileproc *fp, uint64_t wqp_id, struct waitq_set *wqset)
{
        int valid_set = waitq_set_is_valid(wqset);
        int valid_q = !!wqp_id;

        /*
         * This could be called (from selcount error path) before we setup
         * the thread's wqset. Check the wqset passed in, and only unlink if
         * the set is valid.
         */

        /* unlink the underlying waitq from the input set (thread waitq set) */
        if (valid_q && valid_set) {
                waitq_unlink_by_prepost_id(wqp_id, wqset);
        }

        /* allow passing a invalid fp for seldrop unwind */
        if (!(fp->fp_flags & (FP_INSELECT | FP_SELCONFLICT))) {
                return;
        }

        /*
         * We can always remove the conflict queue from our thread's set: this
         * will not affect other threads that potentially need to be awoken on
         * the conflict queue during a fileproc_drain - those sets will still
         * be linked with the global conflict queue, and the last waiter
         * on the fp clears the CONFLICT marker.
         */
        if (valid_set && (fp->fp_flags & FP_SELCONFLICT)) {
                waitq_unlink(&select_conflict_queue, wqset);
        }

        /* jca: TODO:
         * This isn't quite right - we don't actually know if this
         * fileproc is in another select or not! Here we just assume
         * that if we were the first thread to select on the FD, then
         * we'll be the one to clear this flag...
         */
        if (valid_set && fp->fp_wset == (void *)wqset) {
                fp->fp_flags &= ~FP_INSELECT;
                fp->fp_wset = NULL;
        }
}

/**
 * connect a fileproc to the given wqset, potentially bridging to a waitq
 * pointed to indirectly by wq_data
 *
 * Parameters:
 *              fp      File proc potentially currently in select
 *              wq_data Pointer to a pointer to a waitq (could be NULL)
 *              wqset   Waitq set to which the fileproc should now belong
 *                      (usually this is the thread's private waitq set)
 *
 * Conditions:
 *              proc_fdlock is held
 */
static uint64_t
sellinkfp(struct fileproc *fp, void **wq_data, struct waitq_set *wqset)
{
        struct waitq *f_wq = NULL;

        if ((fp->fp_flags & FP_INSELECT) != FP_INSELECT) {
                if (wq_data) {
                        panic("non-null data:%p on fp:%p not in select?!"
                            "(wqset:%p)", wq_data, fp, wqset);
                }
                return 0;
        }

        if ((fp->fp_flags & FP_SELCONFLICT) == FP_SELCONFLICT) {
                waitq_link(&select_conflict_queue, wqset, WAITQ_SHOULD_LOCK, NULL);
        }

        /*
         * The wq_data parameter has potentially been set by selrecord called
         * from a subsystems fo_select() function. If the subsystem does not
         * call selrecord, then wq_data will be NULL
         *
         * Use memcpy to get the value into a proper pointer because
         * wq_data most likely points to a stack variable that could be
         * unaligned on 32-bit systems.
         */
        if (wq_data) {
                memcpy(&f_wq, wq_data, sizeof(f_wq));
                if (!waitq_is_valid(f_wq)) {
                        f_wq = NULL;
                }
        }

        /* record the first thread's wqset in the fileproc structure */
        if (!fp->fp_wset) {
                fp->fp_wset = (void *)wqset;
        }

        /* handles NULL f_wq */
        return waitq_get_prepost_id(f_wq);
}


/*
 * selscan
 *
 * Parameters:  p                       Process performing the select
 *              sel                     The per-thread select context structure
 *              nfd                     The number of file descriptors to scan
 *              retval                  The per thread system call return area
 *              sel_pass                Which pass this is; allowed values are
 *                                              SEL_FIRSTPASS and SEL_SECONDPASS
 *              wqset                   The per thread wait queue set
 *
 * Returns:     0                       Success
 *              EIO                     Invalid p->p_fd field XXX Obsolete?
 *              EBADF                   One of the files in the bit vector is
 *                                              invalid.
 */
static int
selscan(struct proc *p, struct _select *sel, struct _select_data * seldata,
    int nfd, int32_t *retval, int sel_pass, struct waitq_set *wqset)
{
        struct filedesc *fdp = p->p_fd;
        int msk, i, j, fd;
        u_int32_t bits;
        struct fileproc *fp;
        int n = 0;              /* count of bits */
        int nc = 0;             /* bit vector offset (nc'th bit) */
        static int flag[3] = { FREAD, FWRITE, 0 };
        u_int32_t *iptr, *optr;
        u_int nw;
        u_int32_t *ibits, *obits;
        uint64_t reserved_link, *rl_ptr = NULL;
        int count;
        struct vfs_context context = *vfs_context_current();

        /*
         * Problems when reboot; due to MacOSX signal probs
         * in Beaker1C ; verify that the p->p_fd is valid
         */
        if (fdp == NULL) {
                *retval = 0;
                return EIO;
        }
        ibits = sel->ibits;
        obits = sel->obits;

        nw = howmany(nfd, NFDBITS);

        count = seldata->count;

        nc = 0;
        if (!count) {
                *retval = 0;
                return 0;
        }

        proc_fdlock(p);
        for (msk = 0; msk < 3; msk++) {
                iptr = (u_int32_t *)&ibits[msk * nw];
                optr = (u_int32_t *)&obits[msk * nw];

                for (i = 0; i < nfd; i += NFDBITS) {
                        bits = iptr[i / NFDBITS];

                        while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
                                bits &= ~(1U << j);

                                fp = fp_get_noref_locked(p, fd);
                                if (fp == NULL) {
                                        /*
                                         * If we abort because of a bad
                                         * fd, let the caller unwind...
                                         */
                                        proc_fdunlock(p);
                                        return EBADF;
                                }
                                if (sel_pass == SEL_SECONDPASS) {
                                        reserved_link = 0;
                                        rl_ptr = NULL;
                                        selunlinkfp(fp, seldata->wqp[nc], wqset);
                                } else {
                                        reserved_link = waitq_link_reserve((struct waitq *)wqset);
                                        rl_ptr = &reserved_link;
                                        if (fp->fp_flags & FP_INSELECT) {
                                                /* someone is already in select on this fp */
                                                fp->fp_flags |= FP_SELCONFLICT;
                                        } else {
                                                fp->fp_flags |= FP_INSELECT;
                                        }

                                        waitq_set_lazy_init_link(wqset);
                                }

                                context.vc_ucred = fp->f_cred;

                                /*
                                 * stash this value b/c fo_select may replace
                                 * reserved_link with a pointer to a waitq object
                                 */
                                uint64_t rsvd = reserved_link;

                                /* The select; set the bit, if true */
                                if (fp->f_ops && fp->f_type
                                    && fo_select(fp, flag[msk], rl_ptr, &context)) {
                                        optr[fd / NFDBITS] |= (1U << (fd % NFDBITS));
                                        n++;
                                }
                                if (sel_pass == SEL_FIRSTPASS) {
                                        waitq_link_release(rsvd);
                                        /*
                                         * If the fp's supporting selinfo structure was linked
                                         * to this thread's waitq set, then 'reserved_link'
                                         * will have been updated by selrecord to be a pointer
                                         * to the selinfo's waitq.
                                         */
                                        if (reserved_link == rsvd) {
                                                rl_ptr = NULL; /* fo_select never called selrecord() */
                                        }
                                        /*
                                         * Hook up the thread's waitq set either to
                                         * the fileproc structure, or to the global
                                         * conflict queue: but only on the first
                                         * select pass.
                                         */
                                        seldata->wqp[nc] = sellinkfp(fp, (void **)rl_ptr, wqset);
                                }
                                nc++;
                        }
                }
        }
        proc_fdunlock(p);

        *retval = n;
        return 0;
}

static int poll_callback(struct kevent_qos_s *, kevent_ctx_t);

int
poll(struct proc *p, struct poll_args *uap, int32_t *retval)
{
        __pthread_testcancel(1);
        return poll_nocancel(p, (struct poll_nocancel_args *)uap, retval);
}


int
poll_nocancel(struct proc *p, struct poll_nocancel_args *uap, int32_t *retval)
{
        struct pollfd *fds = NULL;
        struct kqueue *kq = NULL;
        int ncoll, error = 0;
        u_int nfds = uap->nfds;
        u_int rfds = 0;
        rlim_t nofile = proc_limitgetcur(p, RLIMIT_NOFILE, TRUE);

        /*
         * This is kinda bogus.  We have fd limits, but that is not
         * really related to the size of the pollfd array.  Make sure
         * we let the process use at least FD_SETSIZE entries and at
         * least enough for the current limits.  We want to be reasonably
         * safe, but not overly restrictive.
         */
        if (nfds > OPEN_MAX ||
            (nfds > nofile && (proc_suser(p) || nfds > FD_SETSIZE))) {
                return EINVAL;
        }

        kq = kqueue_alloc(p);
        if (kq == NULL) {
                return EAGAIN;
        }

        if (nfds) {
                size_t ni = nfds * sizeof(struct pollfd);
                MALLOC(fds, struct pollfd *, ni, M_TEMP, M_WAITOK);
                if (NULL == fds) {
                        error = EAGAIN;
                        goto out;
                }

                error = copyin(uap->fds, fds, nfds * sizeof(struct pollfd));
                if (error) {
                        goto out;
                }
        }

        /* JMM - all this P_SELECT stuff is bogus */
        ncoll = nselcoll;
        OSBitOrAtomic(P_SELECT, &p->p_flag);
        for (u_int i = 0; i < nfds; i++) {
                short events = fds[i].events;
                __assert_only int rc;

                /* per spec, ignore fd values below zero */
                if (fds[i].fd < 0) {
                        fds[i].revents = 0;
                        continue;
                }

                /* convert the poll event into a kqueue kevent */
                struct kevent_qos_s kev = {
                        .ident = fds[i].fd,
                        .flags = EV_ADD | EV_ONESHOT | EV_POLL,
                        .udata = CAST_USER_ADDR_T(&fds[i])
                };

                /* Handle input events */
                if (events & (POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND | POLLHUP)) {
                        kev.filter = EVFILT_READ;
                        if (events & (POLLPRI | POLLRDBAND)) {
                                kev.flags |= EV_OOBAND;
                        }
                        rc = kevent_register(kq, &kev, NULL);
                        assert((rc & FILTER_REGISTER_WAIT) == 0);
                }

                /* Handle output events */
                if ((kev.flags & EV_ERROR) == 0 &&
                    (events & (POLLOUT | POLLWRNORM | POLLWRBAND))) {
                        kev.filter = EVFILT_WRITE;
                        rc = kevent_register(kq, &kev, NULL);
                        assert((rc & FILTER_REGISTER_WAIT) == 0);
                }

                /* Handle BSD extension vnode events */
                if ((kev.flags & EV_ERROR) == 0 &&
                    (events & (POLLEXTEND | POLLATTRIB | POLLNLINK | POLLWRITE))) {
                        kev.filter = EVFILT_VNODE;
                        kev.fflags = 0;
                        if (events & POLLEXTEND) {
                                kev.fflags |= NOTE_EXTEND;
                        }
                        if (events & POLLATTRIB) {
                                kev.fflags |= NOTE_ATTRIB;
                        }
                        if (events & POLLNLINK) {
                                kev.fflags |= NOTE_LINK;
                        }
                        if (events & POLLWRITE) {
                                kev.fflags |= NOTE_WRITE;
                        }
                        rc = kevent_register(kq, &kev, NULL);
                        assert((rc & FILTER_REGISTER_WAIT) == 0);
                }

                if (kev.flags & EV_ERROR) {
                        fds[i].revents = POLLNVAL;
                        rfds++;
                } else {
                        fds[i].revents = 0;
                }
        }

        /*
         * Did we have any trouble registering?
         * If user space passed 0 FDs, then respect any timeout value passed.
         * This is an extremely inefficient sleep. If user space passed one or
         * more FDs, and we had trouble registering _all_ of them, then bail
         * out. If a subset of the provided FDs failed to register, then we
         * will still call the kqueue_scan function.
         */
        if (nfds && (rfds == nfds)) {
                goto done;
        }

        /* scan for, and possibly wait for, the kevents to trigger */
        kevent_ctx_t kectx = kevent_get_context(current_thread());
        *kectx = (struct kevent_ctx_s){
                .kec_process_noutputs = rfds,
                .kec_process_flags    = KEVENT_FLAG_POLL,
                .kec_deadline         = 0, /* wait forever */
        };

        /*
         * If any events have trouble registering, an event has fired and we
         * shouldn't wait for events in kqueue_scan.
         */
        if (rfds) {
                kectx->kec_process_flags |= KEVENT_FLAG_IMMEDIATE;
        } else if (uap->timeout != -1) {
                clock_interval_to_deadline(uap->timeout, NSEC_PER_MSEC,
                    &kectx->kec_deadline);
        }

        error = kqueue_scan(kq, kectx->kec_process_flags, kectx, poll_callback);
        rfds = kectx->kec_process_noutputs;

done:
        OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);
        /* poll is not restarted after signals... */
        if (error == ERESTART) {
                error = EINTR;
        }
        if (error == 0) {
                error = copyout(fds, uap->fds, nfds * sizeof(struct pollfd));
                *retval = rfds;
        }

out:
        if (NULL != fds) {
                FREE(fds, M_TEMP);
        }

        kqueue_dealloc(kq);
        return error;
}

static int
poll_callback(struct kevent_qos_s *kevp, kevent_ctx_t kectx)
{
        struct pollfd *fds = CAST_DOWN(struct pollfd *, kevp->udata);
        short prev_revents = fds->revents;
        short mask = 0;

        /* convert the results back into revents */
        if (kevp->flags & EV_EOF) {
                fds->revents |= POLLHUP;
        }
        if (kevp->flags & EV_ERROR) {
                fds->revents |= POLLERR;
        }

        switch (kevp->filter) {
        case EVFILT_READ:
                if (fds->revents & POLLHUP) {
                        mask = (POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND);
                } else {
                        mask = (POLLIN | POLLRDNORM);
                        if (kevp->flags & EV_OOBAND) {
                                mask |= (POLLPRI | POLLRDBAND);
                        }
                }
                fds->revents |= (fds->events & mask);
                break;

        case EVFILT_WRITE:
                if (!(fds->revents & POLLHUP)) {
                        fds->revents |= (fds->events & (POLLOUT | POLLWRNORM | POLLWRBAND));
                }
                break;

        case EVFILT_VNODE:
                if (kevp->fflags & NOTE_EXTEND) {
                        fds->revents |= (fds->events & POLLEXTEND);
                }
                if (kevp->fflags & NOTE_ATTRIB) {
                        fds->revents |= (fds->events & POLLATTRIB);
                }
                if (kevp->fflags & NOTE_LINK) {
                        fds->revents |= (fds->events & POLLNLINK);
                }
                if (kevp->fflags & NOTE_WRITE) {
                        fds->revents |= (fds->events & POLLWRITE);
                }
                break;
        }

        if (fds->revents != 0 && prev_revents == 0) {
                kectx->kec_process_noutputs++;
        }

        return 0;
}

int
seltrue(__unused dev_t dev, __unused int flag, __unused struct proc *p)
{
        return 1;
}

/*
 * selcount
 *
 * Count the number of bits set in the input bit vector, and establish an
 * outstanding fp->fp_iocount for each of the descriptors which will be in
 * use in the select operation.
 *
 * Parameters:  p                       The process doing the select
 *              ibits                   The input bit vector
 *              nfd                     The number of fd's in the vector
 *              countp                  Pointer to where to store the bit count
 *
 * Returns:     0                       Success
 *              EIO                     Bad per process open file table
 *              EBADF                   One of the bits in the input bit vector
 *                                              references an invalid fd
 *
 * Implicit:    *countp (modified)      Count of fd's
 *
 * Notes:       This function is the first pass under the proc_fdlock() that
 *              permits us to recognize invalid descriptors in the bit vector;
 *              the may, however, not remain valid through the drop and
 *              later reacquisition of the proc_fdlock().
 */
static int
selcount(struct proc *p, u_int32_t *ibits, int nfd, int *countp)
{
        struct filedesc *fdp = p->p_fd;
        int msk, i, j, fd;
        u_int32_t bits;
        struct fileproc *fp;
        int n = 0;
        u_int32_t *iptr;
        u_int nw;
        int error = 0;
        int need_wakeup = 0;

        /*
         * Problems when reboot; due to MacOSX signal probs
         * in Beaker1C ; verify that the p->p_fd is valid
         */
        if (fdp == NULL) {
                *countp = 0;
                return EIO;
        }
        nw = howmany(nfd, NFDBITS);

        proc_fdlock(p);
        for (msk = 0; msk < 3; msk++) {
                iptr = (u_int32_t *)&ibits[msk * nw];
                for (i = 0; i < nfd; i += NFDBITS) {
                        bits = iptr[i / NFDBITS];
                        while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
                                bits &= ~(1U << j);

                                fp = fp_get_noref_locked(p, fd);
                                if (fp == NULL) {
                                        *countp = 0;
                                        error = EBADF;
                                        goto bad;
                                }
                                os_ref_retain_locked(&fp->fp_iocount);
                                n++;
                        }
                }
        }
        proc_fdunlock(p);

        *countp = n;
        return 0;

bad:
        if (n == 0) {
                goto out;
        }
        /* Ignore error return; it's already EBADF */
        (void)seldrop_locked(p, ibits, nfd, n, &need_wakeup);

out:
        proc_fdunlock(p);
        if (need_wakeup) {
                wakeup(&p->p_fpdrainwait);
        }
        return error;
}


/*
 * seldrop_locked
 *
 * Drop outstanding wait queue references set up during selscan(); drop the
 * outstanding per fileproc fp_iocount picked up during the selcount().
 *
 * Parameters:  p                       Process performing the select
 *              ibits                   Input bit bector of fd's
 *              nfd                     Number of fd's
 *              lim                     Limit to number of vector entries to
 *                                              consider, or -1 for "all"
 *              inselect                True if
 *              need_wakeup             Pointer to flag to set to do a wakeup
 *                                      if f_iocont on any descriptor goes to 0
 *
 * Returns:     0                       Success
 *              EBADF                   One or more fds in the bit vector
 *                                              were invalid, but the rest
 *                                              were successfully dropped
 *
 * Notes:       An fd make become bad while the proc_fdlock() is not held,
 *              if a multithreaded application closes the fd out from under
 *              the in progress select.  In this case, we still have to
 *              clean up after the set up on the remaining fds.
 */
static int
seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wakeup)
{
        struct filedesc *fdp = p->p_fd;
        int msk, i, j, nc, fd;
        u_int32_t bits;
        struct fileproc *fp;
        u_int32_t *iptr;
        u_int nw;
        int error = 0;
        uthread_t uth = get_bsdthread_info(current_thread());
        struct _select_data *seldata;

        *need_wakeup = 0;

        /*
         * Problems when reboot; due to MacOSX signal probs
         * in Beaker1C ; verify that the p->p_fd is valid
         */
        if (fdp == NULL) {
                return EIO;
        }

        nw = howmany(nfd, NFDBITS);
        seldata = &uth->uu_save.uus_select_data;

        nc = 0;
        for (msk = 0; msk < 3; msk++) {
                iptr = (u_int32_t *)&ibits[msk * nw];
                for (i = 0; i < nfd; i += NFDBITS) {
                        bits = iptr[i / NFDBITS];
                        while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
                                bits &= ~(1U << j);
                                /*
                                 * If we've already dropped as many as were
                                 * counted/scanned, then we are done.
                                 */
                                if (nc >= lim) {
                                        goto done;
                                }

                                /*
                                 * We took an I/O reference in selcount,
                                 * so the fp can't possibly be NULL.
                                 */
                                fp = fp_get_noref_locked_with_iocount(p, fd);
                                selunlinkfp(fp,
                                    seldata->wqp ? seldata->wqp[nc] : 0,
                                    uth->uu_wqset);

                                nc++;

                                const os_ref_count_t refc = os_ref_release_locked(&fp->fp_iocount);
                                if (0 == refc) {
                                        panic("fp_iocount overdecrement!");
                                }

                                if (1 == refc) {
                                        /*
                                         * The last iocount is responsible for clearing
                                         * selconfict flag - even if we didn't set it -
                                         * and is also responsible for waking up anyone
                                         * waiting on iocounts to drain.
                                         */
                                        if (fp->fp_flags & FP_SELCONFLICT) {
                                                fp->fp_flags &= ~FP_SELCONFLICT;
                                        }
                                        if (p->p_fpdrainwait) {
                                                p->p_fpdrainwait = 0;
                                                *need_wakeup = 1;
                                        }
                                }
                        }
                }
        }
done:
        return error;
}


static int
seldrop(struct proc *p, u_int32_t *ibits, int nfd, int lim)
{
        int error;
        int need_wakeup = 0;

        proc_fdlock(p);
        error = seldrop_locked(p, ibits, nfd, lim, &need_wakeup);
        proc_fdunlock(p);
        if (need_wakeup) {
                wakeup(&p->p_fpdrainwait);
        }
        return error;
}

/*
 * Record a select request.
 */
void
selrecord(__unused struct proc *selector, struct selinfo *sip, void *s_data)
{
        thread_t        cur_act = current_thread();
        struct uthread * ut = get_bsdthread_info(cur_act);
        /* on input, s_data points to the 64-bit ID of a reserved link object */
        uint64_t *reserved_link = (uint64_t *)s_data;

        /* need to look at collisions */

        /*do not record if this is second pass of select */
        if (!s_data) {
                return;
        }

        if ((sip->si_flags & SI_INITED) == 0) {
                waitq_init(&sip->si_waitq, SYNC_POLICY_FIFO);
                sip->si_flags |= SI_INITED;
                sip->si_flags &= ~SI_CLEAR;
        }

        if (sip->si_flags & SI_RECORDED) {
                sip->si_flags |= SI_COLL;
        } else {
                sip->si_flags &= ~SI_COLL;
        }

        sip->si_flags |= SI_RECORDED;
        /* note: this checks for pre-existing linkage */
        waitq_link(&sip->si_waitq, ut->uu_wqset,
            WAITQ_SHOULD_LOCK, reserved_link);

        /*
         * Always consume the reserved link.
         * We can always call waitq_link_release() safely because if
         * waitq_link is successful, it consumes the link and resets the
         * value to 0, in which case our call to release becomes a no-op.
         * If waitq_link fails, then the following release call will actually
         * release the reserved link object.
         */
        waitq_link_release(*reserved_link);
        *reserved_link = 0;

        /*
         * Use the s_data pointer as an output parameter as well
         * This avoids changing the prototype for this function which is
         * used by many kexts. We need to surface the waitq object
         * associated with the selinfo we just added to the thread's select
         * set. New waitq sets do not have back-pointers to set members, so
         * the only way to clear out set linkage objects is to go from the
         * waitq to the set. We use a memcpy because s_data could be
         * pointing to an unaligned value on the stack
         * (especially on 32-bit systems)
         */
        void *wqptr = (void *)&sip->si_waitq;
        memcpy((void *)s_data, (void *)&wqptr, sizeof(void *));

        return;
}

void
selwakeup(struct selinfo *sip)
{
        if ((sip->si_flags & SI_INITED) == 0) {
                return;
        }

        if (sip->si_flags & SI_COLL) {
                nselcoll++;
                sip->si_flags &= ~SI_COLL;
#if 0
                /* will not  support */
                //wakeup((caddr_t)&selwait);
#endif
        }

        if (sip->si_flags & SI_RECORDED) {
                waitq_wakeup64_all(&sip->si_waitq, NO_EVENT64,
                    THREAD_AWAKENED, WAITQ_ALL_PRIORITIES);
                sip->si_flags &= ~SI_RECORDED;
        }
}

void
selthreadclear(struct selinfo *sip)
{
        struct waitq *wq;

        if ((sip->si_flags & SI_INITED) == 0) {
                return;
        }
        if (sip->si_flags & SI_RECORDED) {
                selwakeup(sip);
                sip->si_flags &= ~(SI_RECORDED | SI_COLL);
        }
        sip->si_flags |= SI_CLEAR;
        sip->si_flags &= ~SI_INITED;

        wq = &sip->si_waitq;

        /*
         * Higher level logic may have a handle on this waitq's prepost ID,
         * but that's OK because the waitq_deinit will remove/invalidate the
         * prepost object (as well as mark the waitq invalid). This de-couples
         * us from any callers that may have a handle to this waitq via the
         * prepost ID.
         */
        waitq_deinit(wq);
}


/*
 * gethostuuid
 *
 * Description: Get the host UUID from IOKit and return it to user space.
 *
 * Parameters:  uuid_buf                Pointer to buffer to receive UUID
 *              timeout                 Timespec for timout
 *
 * Returns:     0                       Success
 *              EWOULDBLOCK             Timeout is too short
 *              copyout:EFAULT          Bad user buffer
 *              mac_system_check_info:EPERM             Client not allowed to perform this operation
 *
 * Notes:       A timeout seems redundant, since if it's tolerable to not
 *              have a system UUID in hand, then why ask for one?
 */
int
gethostuuid(struct proc *p, struct gethostuuid_args *uap, __unused int32_t *retval)
{
        kern_return_t kret;
        int error;
        mach_timespec_t mach_ts;        /* for IOKit call */
        __darwin_uuid_t uuid_kern = {}; /* for IOKit call */

        /* Check entitlement */
        if (!IOTaskHasEntitlement(current_task(), "com.apple.private.getprivatesysid")) {
#if !defined(XNU_TARGET_OS_OSX)
#if CONFIG_MACF
                if ((error = mac_system_check_info(kauth_cred_get(), "hw.uuid")) != 0) {
                        /* EPERM invokes userspace upcall if present */
                        return error;
                }
#endif
#endif
        }

        /* Convert the 32/64 bit timespec into a mach_timespec_t */
        if (proc_is64bit(p)) {
                struct user64_timespec ts;
                error = copyin(uap->timeoutp, &ts, sizeof(ts));
                if (error) {
                        return error;
                }
                mach_ts.tv_sec = (unsigned int)ts.tv_sec;
                mach_ts.tv_nsec = (clock_res_t)ts.tv_nsec;
        } else {
                struct user32_timespec ts;
                error = copyin(uap->timeoutp, &ts, sizeof(ts));
                if (error) {
                        return error;
                }
                mach_ts.tv_sec = ts.tv_sec;
                mach_ts.tv_nsec = ts.tv_nsec;
        }

        /* Call IOKit with the stack buffer to get the UUID */
        kret = IOBSDGetPlatformUUID(uuid_kern, mach_ts);

        /*
         * If we get it, copy out the data to the user buffer; note that a
         * uuid_t is an array of characters, so this is size invariant for
         * 32 vs. 64 bit.
         */
        if (kret == KERN_SUCCESS) {
                error = copyout(uuid_kern, uap->uuid_buf, sizeof(uuid_kern));
        } else {
                error = EWOULDBLOCK;
        }

        return error;
}

/*
 * ledger
 *
 * Description: Omnibus system call for ledger operations
 */
int
ledger(struct proc *p, struct ledger_args *args, __unused int32_t *retval)
{
#if !CONFIG_MACF
#pragma unused(p)
#endif
        int rval, pid, len, error;
#ifdef LEDGER_DEBUG
        struct ledger_limit_args lla;
#endif
        task_t task;
        proc_t proc;

        /* Finish copying in the necessary args before taking the proc lock */
        error = 0;
        len = 0;
        if (args->cmd == LEDGER_ENTRY_INFO) {
                error = copyin(args->arg3, (char *)&len, sizeof(len));
        } else if (args->cmd == LEDGER_TEMPLATE_INFO) {
                error = copyin(args->arg2, (char *)&len, sizeof(len));
        } else if (args->cmd == LEDGER_LIMIT)
#ifdef LEDGER_DEBUG
        { error = copyin(args->arg2, (char *)&lla, sizeof(lla));}
#else
        { return EINVAL; }
#endif
        else if ((args->cmd < 0) || (args->cmd > LEDGER_MAX_CMD)) {
                return EINVAL;
        }

        if (error) {
                return error;
        }
        if (len < 0) {
                return EINVAL;
        }

        rval = 0;
        if (args->cmd != LEDGER_TEMPLATE_INFO) {
                pid = (int)args->arg1;
                proc = proc_find(pid);
                if (proc == NULL) {
                        return ESRCH;
                }

#if CONFIG_MACF
                error = mac_proc_check_ledger(p, proc, args->cmd);
                if (error) {
                        proc_rele(proc);
                        return error;
                }
#endif

                task = proc->task;
        }

        switch (args->cmd) {
#ifdef LEDGER_DEBUG
        case LEDGER_LIMIT: {
                if (!kauth_cred_issuser(kauth_cred_get())) {
                        rval = EPERM;
                }
                rval = ledger_limit(task, &lla);
                proc_rele(proc);
                break;
        }
#endif
        case LEDGER_INFO: {
                struct ledger_info info = {};

                rval = ledger_info(task, &info);
                proc_rele(proc);
                if (rval == 0) {
                        rval = copyout(&info, args->arg2,
                            sizeof(info));
                }
                break;
        }

        case LEDGER_ENTRY_INFO: {
                void *buf;
                int sz;

                rval = ledger_get_task_entry_info_multiple(task, &buf, &len);
                proc_rele(proc);
                if ((rval == 0) && (len >= 0)) {
                        sz = len * sizeof(struct ledger_entry_info);
                        rval = copyout(buf, args->arg2, sz);
                        kheap_free(KHEAP_DATA_BUFFERS, buf, sz);
                }
                if (rval == 0) {
                        rval = copyout(&len, args->arg3, sizeof(len));
                }
                break;
        }

        case LEDGER_TEMPLATE_INFO: {
                void *buf;
                int sz;

                rval = ledger_template_info(&buf, &len);
                if ((rval == 0) && (len >= 0)) {
                        sz = len * sizeof(struct ledger_template_info);
                        rval = copyout(buf, args->arg1, sz);
                        kheap_free(KHEAP_DATA_BUFFERS, buf, sz);
                }
                if (rval == 0) {
                        rval = copyout(&len, args->arg2, sizeof(len));
                }
                break;
        }

        default:
                panic("ledger syscall logic error -- command type %d", args->cmd);
                proc_rele(proc);
                rval = EINVAL;
        }

        return rval;
}

int
telemetry(__unused struct proc *p, struct telemetry_args *args, __unused int32_t *retval)
{
        int error = 0;

        switch (args->cmd) {
#if CONFIG_TELEMETRY
        case TELEMETRY_CMD_TIMER_EVENT:
                error = telemetry_timer_event(args->deadline, args->interval, args->leeway);
                break;
        case TELEMETRY_CMD_PMI_SETUP:
                error = telemetry_pmi_setup((enum telemetry_pmi)args->deadline, args->interval);
                break;
#endif /* CONFIG_TELEMETRY */
        case TELEMETRY_CMD_VOUCHER_NAME:
                if (thread_set_voucher_name((mach_port_name_t)args->deadline)) {
                        error = EINVAL;
                }
                break;

        default:
                error = EINVAL;
                break;
        }

        return error;
}

/*
 * Logging
 *
 * Description: syscall to access kernel logging from userspace
 *
 * Args:
 *      tag - used for syncing with userspace on the version.
 *      flags - flags used by the syscall.
 *      buffer - userspace address of string to copy.
 *      size - size of buffer.
 */
int
log_data(__unused struct proc *p, struct log_data_args *args, int *retval)
{
        unsigned int tag = args->tag;
        unsigned int flags = args->flags;
        user_addr_t buffer = args->buffer;
        unsigned int size = args->size;
        int ret = 0;
        char *log_msg = NULL;
        int error;
        *retval = 0;

        /*
         * Tag synchronize the syscall version with userspace.
         * Tag == 0 => flags == OS_LOG_TYPE
         */
        if (tag != 0) {
                return EINVAL;
        }

        /*
         * OS_LOG_TYPE are defined in libkern/os/log.h
         * In userspace they are defined in libtrace/os/log.h
         */
        if (flags != OS_LOG_TYPE_DEFAULT &&
            flags != OS_LOG_TYPE_INFO &&
            flags != OS_LOG_TYPE_DEBUG &&
            flags != OS_LOG_TYPE_ERROR &&
            flags != OS_LOG_TYPE_FAULT) {
                return EINVAL;
        }

        if (size == 0) {
                return EINVAL;
        }

        /* truncate to OS_LOG_DATA_MAX_SIZE */
        if (size > OS_LOG_DATA_MAX_SIZE) {
                printf("%s: WARNING msg is going to be truncated from %u to %u\n",
                    __func__, size, OS_LOG_DATA_MAX_SIZE);
                size = OS_LOG_DATA_MAX_SIZE;
        }

        log_msg = kheap_alloc(KHEAP_TEMP, size, Z_WAITOK);
        if (!log_msg) {
                return ENOMEM;
        }

        error = copyin(buffer, log_msg, size);
        if (error) {
                ret = EFAULT;
                goto out;
        }
        log_msg[size - 1] = '\0';

        /*
         * This will log to dmesg and logd.
         * The call will fail if the current
         * process is not a driverKit process.
         */
        os_log_driverKit(&ret, OS_LOG_DEFAULT, (os_log_type_t)flags, "%s", log_msg);

out:
        if (log_msg != NULL) {
                kheap_free(KHEAP_TEMP, log_msg, size);
        }

        return ret;
}

#if DEVELOPMENT || DEBUG
#if CONFIG_WAITQ_DEBUG
static uint64_t g_wqset_num = 0;
struct g_wqset {
        queue_chain_t      link;
        struct waitq_set  *wqset;
};

static queue_head_t         g_wqset_list;
static struct waitq_set    *g_waitq_set = NULL;

static inline struct waitq_set *
sysctl_get_wqset(int idx)
{
        struct g_wqset *gwqs;

        if (!g_wqset_num) {
                queue_init(&g_wqset_list);
        }

        /* don't bother with locks: this is test-only code! */
        qe_foreach_element(gwqs, &g_wqset_list, link) {
                if ((int)(wqset_id(gwqs->wqset) & 0xffffffff) == idx) {
                        return gwqs->wqset;
                }
        }

        /* allocate a new one */
        ++g_wqset_num;
        gwqs = (struct g_wqset *)kalloc(sizeof(*gwqs));
        assert(gwqs != NULL);

        gwqs->wqset = waitq_set_alloc(SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST, NULL);
        enqueue_tail(&g_wqset_list, &gwqs->link);
        printf("[WQ]: created new waitq set 0x%llx\n", wqset_id(gwqs->wqset));

        return gwqs->wqset;
}

#define MAX_GLOBAL_TEST_QUEUES 64
static int g_wq_init = 0;
static struct waitq  g_wq[MAX_GLOBAL_TEST_QUEUES];

static inline struct waitq *
global_test_waitq(int idx)
{
        if (idx < 0) {
                return NULL;
        }

        if (!g_wq_init) {
                g_wq_init = 1;
                for (int i = 0; i < MAX_GLOBAL_TEST_QUEUES; i++) {
                        waitq_init(&g_wq[i], SYNC_POLICY_FIFO);
                }
        }

        return &g_wq[idx % MAX_GLOBAL_TEST_QUEUES];
}

static int sysctl_waitq_wakeup_one SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        int index;
        struct waitq *waitq;
        kern_return_t kr;
        int64_t event64 = 0;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                return SYSCTL_OUT(req, &event64, sizeof(event64));
        }

        if (event64 < 0) {
                index = (int)((-event64) & 0xffffffff);
                waitq = wqset_waitq(sysctl_get_wqset(index));
                index = -index;
        } else {
                index = (int)event64;
                waitq = global_test_waitq(index);
        }

        event64 = 0;

        printf("[WQ]: Waking one thread on waitq [%d] event:0x%llx\n",
            index, event64);
        kr = waitq_wakeup64_one(waitq, (event64_t)event64, THREAD_AWAKENED,
            WAITQ_ALL_PRIORITIES);
        printf("[WQ]: \tkr=%d\n", kr);

        return SYSCTL_OUT(req, &kr, sizeof(kr));
}
SYSCTL_PROC(_kern, OID_AUTO, waitq_wakeup_one, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_waitq_wakeup_one, "Q", "wakeup one thread waiting on given event");


static int sysctl_waitq_wakeup_all SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        int index;
        struct waitq *waitq;
        kern_return_t kr;
        int64_t event64 = 0;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                return SYSCTL_OUT(req, &event64, sizeof(event64));
        }

        if (event64 < 0) {
                index = (int)((-event64) & 0xffffffff);
                waitq = wqset_waitq(sysctl_get_wqset(index));
                index = -index;
        } else {
                index = (int)event64;
                waitq = global_test_waitq(index);
        }

        event64 = 0;

        printf("[WQ]: Waking all threads on waitq [%d] event:0x%llx\n",
            index, event64);
        kr = waitq_wakeup64_all(waitq, (event64_t)event64,
            THREAD_AWAKENED, WAITQ_ALL_PRIORITIES);
        printf("[WQ]: \tkr=%d\n", kr);

        return SYSCTL_OUT(req, &kr, sizeof(kr));
}
SYSCTL_PROC(_kern, OID_AUTO, waitq_wakeup_all, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_waitq_wakeup_all, "Q", "wakeup all threads waiting on given event");


static int sysctl_waitq_wait SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        int index;
        struct waitq *waitq;
        kern_return_t kr;
        int64_t event64 = 0;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                return SYSCTL_OUT(req, &event64, sizeof(event64));
        }

        if (event64 < 0) {
                index = (int)((-event64) & 0xffffffff);
                waitq = wqset_waitq(sysctl_get_wqset(index));
                index = -index;
        } else {
                index = (int)event64;
                waitq = global_test_waitq(index);
        }

        event64 = 0;

        printf("[WQ]: Current thread waiting on waitq [%d] event:0x%llx\n",
            index, event64);
        kr = waitq_assert_wait64(waitq, (event64_t)event64, THREAD_INTERRUPTIBLE, 0);
        if (kr == THREAD_WAITING) {
                thread_block(THREAD_CONTINUE_NULL);
        }
        printf("[WQ]: \tWoke Up: kr=%d\n", kr);

        return SYSCTL_OUT(req, &kr, sizeof(kr));
}
SYSCTL_PROC(_kern, OID_AUTO, waitq_wait, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_waitq_wait, "Q", "start waiting on given event");


static int sysctl_wqset_select SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        struct waitq_set *wqset;
        uint64_t event64 = 0;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                goto out;
        }

        wqset = sysctl_get_wqset((int)(event64 & 0xffffffff));
        g_waitq_set = wqset;

        event64 = wqset_id(wqset);
        printf("[WQ]: selected wqset 0x%llx\n", event64);

out:
        if (g_waitq_set) {
                event64 = wqset_id(g_waitq_set);
        } else {
                event64 = (uint64_t)(-1);
        }

        return SYSCTL_OUT(req, &event64, sizeof(event64));
}
SYSCTL_PROC(_kern, OID_AUTO, wqset_select, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_wqset_select, "Q", "select/create a global waitq set");


static int sysctl_waitq_link SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        int index;
        struct waitq *waitq;
        struct waitq_set *wqset;
        kern_return_t kr;
        uint64_t reserved_link = 0;
        int64_t event64 = 0;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                return SYSCTL_OUT(req, &event64, sizeof(event64));
        }

        if (!g_waitq_set) {
                g_waitq_set = sysctl_get_wqset(1);
        }
        wqset = g_waitq_set;

        if (event64 < 0) {
                struct waitq_set *tmp;
                index = (int)((-event64) & 0xffffffff);
                tmp = sysctl_get_wqset(index);
                if (tmp == wqset) {
                        goto out;
                }
                waitq = wqset_waitq(tmp);
                index = -index;
        } else {
                index = (int)event64;
                waitq = global_test_waitq(index);
        }

        printf("[WQ]: linking waitq [%d] to global wqset (0x%llx)\n",
            index, wqset_id(wqset));
        reserved_link = waitq_link_reserve(waitq);
        kr = waitq_link(waitq, wqset, WAITQ_SHOULD_LOCK, &reserved_link);
        waitq_link_release(reserved_link);

        printf("[WQ]: \tkr=%d\n", kr);

out:
        return SYSCTL_OUT(req, &kr, sizeof(kr));
}
SYSCTL_PROC(_kern, OID_AUTO, waitq_link, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_waitq_link, "Q", "link global waitq to test waitq set");


static int sysctl_waitq_unlink SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        int index;
        struct waitq *waitq;
        struct waitq_set *wqset;
        kern_return_t kr;
        uint64_t event64 = 0;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                return SYSCTL_OUT(req, &event64, sizeof(event64));
        }

        if (!g_waitq_set) {
                g_waitq_set = sysctl_get_wqset(1);
        }
        wqset = g_waitq_set;

        index = (int)event64;
        waitq = global_test_waitq(index);

        printf("[WQ]: unlinking waitq [%d] from global wqset (0x%llx)\n",
            index, wqset_id(wqset));

        kr = waitq_unlink(waitq, wqset);
        printf("[WQ]: \tkr=%d\n", kr);

        return SYSCTL_OUT(req, &kr, sizeof(kr));
}
SYSCTL_PROC(_kern, OID_AUTO, waitq_unlink, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_waitq_unlink, "Q", "unlink global waitq from test waitq set");


static int sysctl_waitq_clear_prepost SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        struct waitq *waitq;
        uint64_t event64 = 0;
        int error, index;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                return SYSCTL_OUT(req, &event64, sizeof(event64));
        }

        index = (int)event64;
        waitq = global_test_waitq(index);

        printf("[WQ]: clearing prepost on waitq [%d]\n", index);
        waitq_clear_prepost(waitq);

        return SYSCTL_OUT(req, &event64, sizeof(event64));
}
SYSCTL_PROC(_kern, OID_AUTO, waitq_clear_prepost, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_waitq_clear_prepost, "Q", "clear prepost on given waitq");


static int sysctl_wqset_unlink_all SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        struct waitq_set *wqset;
        kern_return_t kr;
        uint64_t event64 = 0;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                return SYSCTL_OUT(req, &event64, sizeof(event64));
        }

        if (!g_waitq_set) {
                g_waitq_set = sysctl_get_wqset(1);
        }
        wqset = g_waitq_set;

        printf("[WQ]: unlinking all queues from global wqset (0x%llx)\n",
            wqset_id(wqset));

        kr = waitq_set_unlink_all(wqset);
        printf("[WQ]: \tkr=%d\n", kr);

        return SYSCTL_OUT(req, &kr, sizeof(kr));
}
SYSCTL_PROC(_kern, OID_AUTO, wqset_unlink_all, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_wqset_unlink_all, "Q", "unlink all queues from test waitq set");


static int sysctl_wqset_clear_preposts SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        struct waitq_set *wqset = NULL;
        uint64_t event64 = 0;
        int error, index;

        error = SYSCTL_IN(req, &event64, sizeof(event64));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                goto out;
        }

        index = (int)((event64) & 0xffffffff);
        wqset = sysctl_get_wqset(index);
        assert(wqset != NULL);

        printf("[WQ]: clearing preposts on wqset 0x%llx\n", wqset_id(wqset));
        waitq_set_clear_preposts(wqset);

out:
        if (wqset) {
                event64 = wqset_id(wqset);
        } else {
                event64 = (uint64_t)(-1);
        }

        return SYSCTL_OUT(req, &event64, sizeof(event64));
}
SYSCTL_PROC(_kern, OID_AUTO, wqset_clear_preposts, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_wqset_clear_preposts, "Q", "clear preposts on given waitq set");

#endif /* CONFIG_WAITQ_DEBUG */

static int
sysctl_waitq_set_nelem SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int nelem;

        /* Read only  */
        if (req->newptr != USER_ADDR_NULL) {
                return EPERM;
        }

        nelem = sysctl_helper_waitq_set_nelem();

        return SYSCTL_OUT(req, &nelem, sizeof(nelem));
}

SYSCTL_PROC(_kern, OID_AUTO, n_ltable_entries, CTLFLAG_RD | CTLFLAG_LOCKED,
    0, 0, sysctl_waitq_set_nelem, "I", "ltable elementis currently used");


static int
sysctl_mpsc_test_pingpong SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        uint64_t value = 0;
        int error;

        error = SYSCTL_IN(req, &value, sizeof(value));
        if (error) {
                return error;
        }

        if (error == 0 && req->newptr) {
                error = mpsc_test_pingpong(value, &value);
                if (error == 0) {
                        error = SYSCTL_OUT(req, &value, sizeof(value));
                }
        }

        return error;
}
SYSCTL_PROC(_kern, OID_AUTO, mpsc_test_pingpong, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_mpsc_test_pingpong, "Q", "MPSC tests: pingpong");

#endif /* DEVELOPMENT || DEBUG */

/*Remote Time api*/
SYSCTL_NODE(_machdep, OID_AUTO, remotetime, CTLFLAG_RD | CTLFLAG_LOCKED, 0, "Remote time api");

#if DEVELOPMENT || DEBUG
#if CONFIG_MACH_BRIDGE_SEND_TIME
extern _Atomic uint32_t bt_init_flag;
extern uint32_t mach_bridge_timer_enable(uint32_t, int);

SYSCTL_INT(_machdep_remotetime, OID_AUTO, bridge_timer_init_flag,
    CTLFLAG_RD | CTLFLAG_LOCKED, &bt_init_flag, 0, "");

static int sysctl_mach_bridge_timer_enable SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        uint32_t value = 0;
        int error = 0;
        /* User is querying buffer size */
        if (req->oldptr == USER_ADDR_NULL && req->newptr == USER_ADDR_NULL) {
                req->oldidx = sizeof(value);
                return 0;
        }
        if (os_atomic_load(&bt_init_flag, acquire)) {
                if (req->newptr) {
                        int new_value = 0;
                        error = SYSCTL_IN(req, &new_value, sizeof(new_value));
                        if (error) {
                                return error;
                        }
                        if (new_value == 0 || new_value == 1) {
                                value = mach_bridge_timer_enable(new_value, 1);
                        } else {
                                return EPERM;
                        }
                } else {
                        value = mach_bridge_timer_enable(0, 0);
                }
        }
        error = SYSCTL_OUT(req, &value, sizeof(value));
        return error;
}

SYSCTL_PROC(_machdep_remotetime, OID_AUTO, bridge_timer_enable,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_mach_bridge_timer_enable, "I", "");

#endif /* CONFIG_MACH_BRIDGE_SEND_TIME */

static int sysctl_mach_bridge_remote_time SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        uint64_t ltime = 0, rtime = 0;
        if (req->oldptr == USER_ADDR_NULL) {
                req->oldidx = sizeof(rtime);
                return 0;
        }
        if (req->newptr) {
                int error = SYSCTL_IN(req, &ltime, sizeof(ltime));
                if (error) {
                        return error;
                }
        }
        rtime = mach_bridge_remote_time(ltime);
        return SYSCTL_OUT(req, &rtime, sizeof(rtime));
}
SYSCTL_PROC(_machdep_remotetime, OID_AUTO, mach_bridge_remote_time,
    CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_mach_bridge_remote_time, "Q", "");

#endif /* DEVELOPMENT || DEBUG */

#if CONFIG_MACH_BRIDGE_RECV_TIME
extern struct bt_params bt_params_get_latest(void);

static int sysctl_mach_bridge_conversion_params SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        struct bt_params params = {};
        if (req->oldptr == USER_ADDR_NULL) {
                req->oldidx = sizeof(struct bt_params);
                return 0;
        }
        if (req->newptr) {
                return EPERM;
        }
        params = bt_params_get_latest();
        return SYSCTL_OUT(req, &params, MIN(sizeof(params), req->oldlen));
}

SYSCTL_PROC(_machdep_remotetime, OID_AUTO, conversion_params,
    CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0,
    0, sysctl_mach_bridge_conversion_params, "S,bt_params", "");

#endif /* CONFIG_MACH_BRIDGE_RECV_TIME */

#if DEVELOPMENT || DEBUG
#if __AMP__
#include <pexpert/pexpert.h>
extern int32_t sysctl_get_bound_cpuid(void);
extern void sysctl_thread_bind_cpuid(int32_t cpuid);
static int
sysctl_kern_sched_thread_bind_cpu SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)

        if (!PE_parse_boot_argn("enable_skstb", NULL, 0)) {
                return ENOENT;
        }

        int32_t cpuid = sysctl_get_bound_cpuid();

        int32_t new_value;
        int changed;
        int error = sysctl_io_number(req, cpuid, sizeof cpuid, &new_value, &changed);
        if (error) {
                return error;
        }

        if (changed) {
                sysctl_thread_bind_cpuid(new_value);
        }

        return error;
}

SYSCTL_PROC(_kern, OID_AUTO, sched_thread_bind_cpu, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_kern_sched_thread_bind_cpu, "I", "");

extern char sysctl_get_bound_cluster_type(void);
extern void sysctl_thread_bind_cluster_type(char cluster_type);
static int
sysctl_kern_sched_thread_bind_cluster_type SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        char buff[4];

        if (!PE_parse_boot_argn("enable_skstb", NULL, 0)) {
                return ENOENT;
        }

        int error = SYSCTL_IN(req, buff, 1);
        if (error) {
                return error;
        }
        char cluster_type = buff[0];

        if (!req->newptr) {
                goto out;
        }

        sysctl_thread_bind_cluster_type(cluster_type);
out:
        cluster_type = sysctl_get_bound_cluster_type();
        buff[0] = cluster_type;

        return SYSCTL_OUT(req, buff, 1);
}

SYSCTL_PROC(_kern, OID_AUTO, sched_thread_bind_cluster_type, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_kern_sched_thread_bind_cluster_type, "A", "");

extern char sysctl_get_task_cluster_type(void);
extern void sysctl_task_set_cluster_type(char cluster_type);
static int
sysctl_kern_sched_task_set_cluster_type SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        char buff[4];

        if (!PE_parse_boot_argn("enable_skstsct", NULL, 0)) {
                return ENOENT;
        }

        int error = SYSCTL_IN(req, buff, 1);
        if (error) {
                return error;
        }
        char cluster_type = buff[0];

        if (!req->newptr) {
                goto out;
        }

        sysctl_task_set_cluster_type(cluster_type);
out:
        cluster_type = sysctl_get_task_cluster_type();
        buff[0] = cluster_type;

        return SYSCTL_OUT(req, buff, 1);
}

SYSCTL_PROC(_kern, OID_AUTO, sched_task_set_cluster_type, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_kern_sched_task_set_cluster_type, "A", "");

#if CONFIG_SCHED_EDGE

/*
 * Edge Scheduler Sysctls
 *
 * The Edge scheduler uses edge configurations to decide feasability of
 * migrating threads across clusters. The sysctls allow dynamic configuration
 * of the edge properties and edge weights. This configuration is typically
 * updated via callouts from CLPC.
 *
 * <Edge Multi-cluster Support Needed>
 */
extern sched_clutch_edge sched_edge_config_e_to_p;
extern sched_clutch_edge sched_edge_config_p_to_e;
extern kern_return_t sched_edge_sysctl_configure_e_to_p(uint64_t);
extern kern_return_t sched_edge_sysctl_configure_p_to_e(uint64_t);
extern sched_clutch_edge sched_edge_e_to_p(void);
extern sched_clutch_edge sched_edge_p_to_e(void);

static int sysctl_sched_edge_config_e_to_p SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        kern_return_t kr;
        int64_t edge_config = 0;

        error = SYSCTL_IN(req, &edge_config, sizeof(edge_config));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                edge_config = sched_edge_e_to_p().sce_edge_packed;
                return SYSCTL_OUT(req, &edge_config, sizeof(edge_config));
        }

        kr = sched_edge_sysctl_configure_e_to_p(edge_config);
        return SYSCTL_OUT(req, &kr, sizeof(kr));
}
SYSCTL_PROC(_kern, OID_AUTO, sched_edge_config_e_to_p, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_sched_edge_config_e_to_p, "Q", "Edge Scheduler Config for E-to-P cluster");

static int sysctl_sched_edge_config_p_to_e SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int error;
        kern_return_t kr;
        int64_t edge_config = 0;

        error = SYSCTL_IN(req, &edge_config, sizeof(edge_config));
        if (error) {
                return error;
        }

        if (!req->newptr) {
                edge_config = sched_edge_p_to_e().sce_edge_packed;
                return SYSCTL_OUT(req, &edge_config, sizeof(edge_config));
        }

        kr = sched_edge_sysctl_configure_p_to_e(edge_config);
        return SYSCTL_OUT(req, &kr, sizeof(kr));
}
SYSCTL_PROC(_kern, OID_AUTO, sched_edge_config_p_to_e, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_sched_edge_config_p_to_e, "Q", "Edge Scheduler Config for P-to-E cluster");

extern int sched_edge_restrict_ut;
SYSCTL_INT(_kern, OID_AUTO, sched_edge_restrict_ut, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_restrict_ut, 0, "Edge Scheduler Restrict UT Threads");
extern int sched_edge_restrict_bg;
SYSCTL_INT(_kern, OID_AUTO, sched_edge_restrict_bg, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_restrict_ut, 0, "Edge Scheduler Restrict BG Threads");
extern int sched_edge_migrate_ipi_immediate;
SYSCTL_INT(_kern, OID_AUTO, sched_edge_migrate_ipi_immediate, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_migrate_ipi_immediate, 0, "Edge Scheduler uses immediate IPIs for migration event based on execution latency");

#endif /* CONFIG_SCHED_EDGE */

#endif /* __AMP__ */
#endif /* DEVELOPMENT || DEBUG */

extern uint32_t task_exc_guard_default;

SYSCTL_INT(_kern, OID_AUTO, task_exc_guard_default,
    CTLFLAG_RD | CTLFLAG_LOCKED, &task_exc_guard_default, 0, "");


static int
sysctl_kern_tcsm_available SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        uint32_t value = machine_csv(CPUVN_CI) ? 1 : 0;

        if (req->newptr) {
                return EINVAL;
        }

        return SYSCTL_OUT(req, &value, sizeof(value));
}
SYSCTL_PROC(_kern, OID_AUTO, tcsm_available,
    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_LOCKED | CTLFLAG_MASKED | CTLFLAG_ANYBODY,
    0, 0, sysctl_kern_tcsm_available, "I", "");


static int
sysctl_kern_tcsm_enable SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        uint32_t soflags = 0;
        uint32_t old_value = thread_get_no_smt() ? 1 : 0;

        int error = SYSCTL_IN(req, &soflags, sizeof(soflags));
        if (error) {
                return error;
        }

        if (soflags && machine_csv(CPUVN_CI)) {
                thread_set_no_smt(true);
                machine_tecs(current_thread());
        }

        return SYSCTL_OUT(req, &old_value, sizeof(old_value));
}
SYSCTL_PROC(_kern, OID_AUTO, tcsm_enable,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED | CTLFLAG_ANYBODY,
    0, 0, sysctl_kern_tcsm_enable, "I", "");


#if DEVELOPMENT || DEBUG
extern void sysctl_task_set_no_smt(char no_smt);
extern char sysctl_task_get_no_smt(void);

static int
sysctl_kern_sched_task_set_no_smt SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        char buff[4];

        int error = SYSCTL_IN(req, buff, 1);
        if (error) {
                return error;
        }
        char no_smt = buff[0];

        if (!req->newptr) {
                goto out;
        }

        sysctl_task_set_no_smt(no_smt);
out:
        no_smt = sysctl_task_get_no_smt();
        buff[0] = no_smt;

        return SYSCTL_OUT(req, buff, 1);
}

SYSCTL_PROC(_kern, OID_AUTO, sched_task_set_no_smt, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_ANYBODY,
    0, 0, sysctl_kern_sched_task_set_no_smt, "A", "");

static int
sysctl_kern_sched_thread_set_no_smt(__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req)
{
        int new_value, changed;
        int old_value = thread_get_no_smt() ? 1 : 0;
        int error = sysctl_io_number(req, old_value, sizeof(int), &new_value, &changed);

        if (changed) {
                thread_set_no_smt(!!new_value);
        }

        return error;
}

SYSCTL_PROC(_kern, OID_AUTO, sched_thread_set_no_smt,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_ANYBODY,
    0, 0, sysctl_kern_sched_thread_set_no_smt, "I", "");

static int
sysctl_kern_debug_get_preoslog SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        static bool oneshot_executed = false;
        size_t preoslog_size = 0;
        const char *preoslog = NULL;

        // DumpPanic pases a non-zero write value when it needs oneshot behaviour
        if (req->newptr) {
                uint8_t oneshot = 0;
                int error = SYSCTL_IN(req, &oneshot, sizeof(oneshot));
                if (error) {
                        return error;
                }

                if (oneshot) {
                        if (!OSCompareAndSwap8(false, true, &oneshot_executed)) {
                                return EPERM;
                        }
                }
        }

        preoslog = sysctl_debug_get_preoslog(&preoslog_size);
        if (preoslog == NULL || preoslog_size == 0) {
                return 0;
        }

        if (req->oldptr == USER_ADDR_NULL) {
                req->oldidx = preoslog_size;
                return 0;
        }

        return SYSCTL_OUT(req, preoslog, preoslog_size);
}

SYSCTL_PROC(_kern, OID_AUTO, preoslog, CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_kern_debug_get_preoslog, "-", "");

static int
sysctl_kern_task_set_filter_msg_flag SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
        int new_value, changed;
        int old_value = task_get_filter_msg_flag(current_task()) ? 1 : 0;
        int error = sysctl_io_number(req, old_value, sizeof(int), &new_value, &changed);

        if (changed) {
                task_set_filter_msg_flag(current_task(), !!new_value);
        }

        return error;
}

SYSCTL_PROC(_kern, OID_AUTO, task_set_filter_msg_flag, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
    0, 0, sysctl_kern_task_set_filter_msg_flag, "I", "");

#endif /* DEVELOPMENT || DEBUG */