xref: /illumos-gate/usr/src/uts/common/os/zone.c (revision 4de2612967d06c4fdbf524a62556a1e8118a006f)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * Zones
 *
 *   A zone is a named collection of processes, namespace constraints,
 *   and other system resources which comprise a secure and manageable
 *   application containment facility.
 *
 *   Zones (represented by the reference counted zone_t) are tracked in
 *   the kernel in the zonehash.  Elsewhere in the kernel, Zone IDs
 *   (zoneid_t) are used to track zone association.  Zone IDs are
 *   dynamically generated when the zone is created; if a persistent
 *   identifier is needed (core files, accounting logs, audit trail,
 *   etc.), the zone name should be used.
 *
 *
 *   Global Zone:
 *
 *   The global zone (zoneid 0) is automatically associated with all
 *   system resources that have not been bound to a user-created zone.
 *   This means that even systems where zones are not in active use
 *   have a global zone, and all processes, mounts, etc. are
 *   associated with that zone.  The global zone is generally
 *   unconstrained in terms of privileges and access, though the usual
 *   credential and privilege based restrictions apply.
 *
 *
 *   Zone States:
 *
 *   The states in which a zone may be in and the transitions are as
 *   follows:
 *
 *   ZONE_IS_UNINITIALIZED: primordial state for a zone. The partially
 *   initialized zone is added to the list of active zones on the system but
 *   isn't accessible.
 *
 *   ZONE_IS_READY: zsched (the kernel dummy process for a zone) is
 *   ready.  The zone is made visible after the ZSD constructor callbacks are
 *   executed.  A zone remains in this state until it transitions into
 *   the ZONE_IS_BOOTING state as a result of a call to zone_boot().
 *
 *   ZONE_IS_BOOTING: in this shortlived-state, zsched attempts to start
 *   init.  Should that fail, the zone proceeds to the ZONE_IS_SHUTTING_DOWN
 *   state.
 *
 *   ZONE_IS_RUNNING: The zone is open for business: zsched has
 *   successfully started init.   A zone remains in this state until
 *   zone_shutdown() is called.
 *
 *   ZONE_IS_SHUTTING_DOWN: zone_shutdown() has been called, the system is
 *   killing all processes running in the zone. The zone remains
 *   in this state until there are no more user processes running in the zone.
 *   zone_create(), zone_enter(), and zone_destroy() on this zone will fail.
 *   Since zone_shutdown() is restartable, it may be called successfully
 *   multiple times for the same zone_t.  Setting of the zone's state to
 *   ZONE_IS_SHUTTING_DOWN is synchronized with mounts, so VOP_MOUNT() may check
 *   the zone's status without worrying about it being a moving target.
 *
 *   ZONE_IS_EMPTY: zone_shutdown() has been called, and there
 *   are no more user processes in the zone.  The zone remains in this
 *   state until there are no more kernel threads associated with the
 *   zone.  zone_create(), zone_enter(), and zone_destroy() on this zone will
 *   fail.
 *
 *   ZONE_IS_DOWN: All kernel threads doing work on behalf of the zone
 *   have exited.  zone_shutdown() returns.  Henceforth it is not possible to
 *   join the zone or create kernel threads therein.
 *
 *   ZONE_IS_DYING: zone_destroy() has been called on the zone; zone
 *   remains in this state until zsched exits.  Calls to zone_find_by_*()
 *   return NULL from now on.
 *
 *   ZONE_IS_DEAD: zsched has exited (zone_ntasks == 0).  There are no
 *   processes or threads doing work on behalf of the zone.  The zone is
 *   removed from the list of active zones.  zone_destroy() returns, and
 *   the zone can be recreated.
 *
 *   ZONE_IS_FREE (internal state): zone_ref goes to 0, ZSD destructor
 *   callbacks are executed, and all memory associated with the zone is
 *   freed.
 *
 *   Threads can wait for the zone to enter a requested state by using
 *   zone_status_wait() or zone_status_timedwait() with the desired
 *   state passed in as an argument.  Zone state transitions are
 *   uni-directional; it is not possible to move back to an earlier state.
 *
 *
 *   Zone-Specific Data:
 *
 *   Subsystems needing to maintain zone-specific data can store that
 *   data using the ZSD mechanism.  This provides a zone-specific data
 *   store, similar to thread-specific data (see pthread_getspecific(3C)
 *   or the TSD code in uts/common/disp/thread.c.  Also, ZSD can be used
 *   to register callbacks to be invoked when a zone is created, shut
 *   down, or destroyed.  This can be used to initialize zone-specific
 *   data for new zones and to clean up when zones go away.
 *
 *
 *   Data Structures:
 *
 *   The per-zone structure (zone_t) is reference counted, and freed
 *   when all references are released.  zone_hold and zone_rele can be
 *   used to adjust the reference count.  In addition, reference counts
 *   associated with the cred_t structure are tracked separately using
 *   zone_cred_hold and zone_cred_rele.
 *
 *   Pointers to active zone_t's are stored in two hash tables; one
 *   for searching by id, the other for searching by name.  Lookups
 *   can be performed on either basis, using zone_find_by_id and
 *   zone_find_by_name.  Both return zone_t pointers with the zone
 *   held, so zone_rele should be called when the pointer is no longer
 *   needed.  Zones can also be searched by path; zone_find_by_path
 *   returns the zone with which a path name is associated (global
 *   zone if the path is not within some other zone's file system
 *   hierarchy).  This currently requires iterating through each zone,
 *   so it is slower than an id or name search via a hash table.
 *
 *
 *   Locking:
 *
 *   zonehash_lock: This is a top-level global lock used to protect the
 *       zone hash tables and lists.  Zones cannot be created or destroyed
 *       while this lock is held.
 *   zone_status_lock: This is a global lock protecting zone state.
 *       Zones cannot change state while this lock is held.  It also
 *       protects the list of kernel threads associated with a zone.
 *   zone_lock: This is a per-zone lock used to protect several fields of
 *       the zone_t (see <sys/zone.h> for details).  In addition, holding
 *       this lock means that the zone cannot go away.
 *   zsd_key_lock: This is a global lock protecting the key state for ZSD.
 *   zone_deathrow_lock: This is a global lock protecting the "deathrow"
 *       list (a list of zones in the ZONE_IS_DEAD state).
 *
 *   Ordering requirements:
 *       pool_lock --> cpu_lock --> zonehash_lock --> zone_status_lock -->
 *       	zone_lock --> zsd_key_lock --> pidlock --> p_lock
 *
 *   Blocking memory allocations are permitted while holding any of the
 *   zone locks.
 *
 *
 *   System Call Interface:
 *
 *   The zone subsystem can be managed and queried from user level with
 *   the following system calls (all subcodes of the primary "zone"
 *   system call):
 *   - zone_create: creates a zone with selected attributes (name,
 *     root path, privileges, resource controls, ZFS datasets)
 *   - zone_enter: allows the current process to enter a zone
 *   - zone_getattr: reports attributes of a zone
 *   - zone_list: lists all zones active in the system
 *   - zone_lookup: looks up zone id based on name
 *   - zone_shutdown: initiates shutdown process (see states above)
 *   - zone_destroy: completes shutdown process (see states above)
 *
 */

#include <sys/priv_impl.h>
#include <sys/cred.h>
#include <c2/audit.h>
#include <sys/ddi.h>
#include <sys/debug.h>
#include <sys/file.h>
#include <sys/kmem.h>
#include <sys/mutex.h>
#include <sys/pathname.h>
#include <sys/proc.h>
#include <sys/project.h>
#include <sys/task.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <sys/vnode.h>
#include <sys/vfs.h>
#include <sys/systeminfo.h>
#include <sys/policy.h>
#include <sys/cred_impl.h>
#include <sys/contract_impl.h>
#include <sys/contract/process_impl.h>
#include <sys/class.h>
#include <sys/pool.h>
#include <sys/pool_pset.h>
#include <sys/pset.h>
#include <sys/log.h>
#include <sys/sysmacros.h>
#include <sys/callb.h>
#include <sys/vmparam.h>
#include <sys/corectl.h>

#include <sys/door.h>
#include <sys/cpuvar.h>
#include <sys/fs/snode.h>

#include <sys/uadmin.h>
#include <sys/session.h>
#include <sys/cmn_err.h>
#include <sys/modhash.h>
#include <sys/nvpair.h>
#include <sys/rctl.h>
#include <sys/fss.h>
#include <sys/zone.h>

/*
 * cv used to signal that all references to the zone have been released.  This
 * needs to be global since there may be multiple waiters, and the first to
 * wake up will free the zone_t, hence we cannot use zone->zone_cv.
 */
static kcondvar_t zone_destroy_cv;
/*
 * Lock used to serialize access to zone_cv.  This could have been per-zone,
 * but then we'd need another lock for zone_destroy_cv, and why bother?
 */
static kmutex_t zone_status_lock;

/*
 * ZSD-related global variables.
 */
static kmutex_t zsd_key_lock;	/* protects the following two */
/*
 * The next caller of zone_key_create() will be assigned a key of ++zsd_keyval.
 */
static zone_key_t zsd_keyval = 0;
/*
 * Global list of registered keys.  We use this when a new zone is created.
 */
static list_t zsd_registered_keys;

int zone_hash_size = 256;
static mod_hash_t *zonehashbyname, *zonehashbyid;
static kmutex_t zonehash_lock;
static uint_t zonecount;
static id_space_t *zoneid_space;

/*
 * The global zone (aka zone0) is the all-seeing, all-knowing zone in which the
 * kernel proper runs, and which manages all other zones.
 *
 * Although not declared as static, the variable "zone0" should not be used
 * except for by code that needs to reference the global zone early on in boot,
 * before it is fully initialized.  All other consumers should use
 * 'global_zone'.
 */
zone_t zone0;
zone_t *global_zone = NULL;	/* Set when the global zone is initialized */

/*
 * List of active zones, protected by zonehash_lock.
 */
static list_t zone_active;

/*
 * List of destroyed zones that still have outstanding cred references.
 * Used for debugging.  Uses a separate lock to avoid lock ordering
 * problems in zone_free.
 */
static list_t zone_deathrow;
static kmutex_t zone_deathrow_lock;

/* number of zones is limited by virtual interface limit in IP */
uint_t maxzones = 8192;

/*
 * This isn't static so lint doesn't complain.
 */
rctl_hndl_t rc_zone_cpu_shares;
rctl_hndl_t rc_zone_nlwps;
/*
 * Synchronization primitives used to synchronize between mounts and zone
 * creation/destruction.
 */
static int mounts_in_progress;
static kcondvar_t mount_cv;
static kmutex_t mount_lock;

const char * const zone_initname = "/sbin/init";

static int zone_shutdown(zoneid_t zoneid);

/*
 * Bump this number when you alter the zone syscall interfaces; this is
 * because we need to have support for previous API versions in libc
 * to support patching; libc calls into the kernel to determine this number.
 *
 * Version 1 of the API is the version originally shipped with Solaris 10
 * Version 2 alters the zone_create system call in order to support more
 *     arguments by moving the args into a structure; and to do better
 *     error reporting when zone_create() fails.
 * Version 3 alters the zone_create system call in order to support the
 *     import of ZFS datasets to zones.
 */
static const int ZONE_SYSCALL_API_VERSION = 3;

/*
 * Certain filesystems (such as NFS and autofs) need to know which zone
 * the mount is being placed in.  Because of this, we need to be able to
 * ensure that a zone isn't in the process of being created such that
 * nfs_mount() thinks it is in the global zone, while by the time it
 * gets added the list of mounted zones, it ends up on zoneA's mount
 * list.
 *
 * The following functions: block_mounts()/resume_mounts() and
 * mount_in_progress()/mount_completed() are used by zones and the VFS
 * layer (respectively) to synchronize zone creation and new mounts.
 *
 * The semantics are like a reader-reader lock such that there may
 * either be multiple mounts (or zone creations, if that weren't
 * serialized by zonehash_lock) in progress at the same time, but not
 * both.
 *
 * We use cv's so the user can ctrl-C out of the operation if it's
 * taking too long.
 *
 * The semantics are such that there is unfair bias towards the
 * "current" operation.  This means that zone creations may starve if
 * there is a rapid succession of new mounts coming in to the system, or
 * there is a remote possibility that zones will be created at such a
 * rate that new mounts will not be able to proceed.
 */
/*
 * Prevent new mounts from progressing to the point of calling
 * VFS_MOUNT().  If there are already mounts in this "region", wait for
 * them to complete.
 */
static int
block_mounts(void)
{
	int retval = 0;

	/*
	 * Since it may block for a long time, block_mounts() shouldn't be
	 * called with zonehash_lock held.
	 */
	ASSERT(MUTEX_NOT_HELD(&zonehash_lock));
	mutex_enter(&mount_lock);
	while (mounts_in_progress > 0) {
		if (cv_wait_sig(&mount_cv, &mount_lock) == 0)
			goto signaled;
	}
	/*
	 * A negative value of mounts_in_progress indicates that mounts
	 * have been blocked by (-mounts_in_progress) different callers.
	 */
	mounts_in_progress--;
	retval = 1;
signaled:
	mutex_exit(&mount_lock);
	return (retval);
}

/*
 * The VFS layer may progress with new mounts as far as we're concerned.
 * Allow them to progress if we were the last obstacle.
 */
static void
resume_mounts(void)
{
	mutex_enter(&mount_lock);
	if (++mounts_in_progress == 0)
		cv_broadcast(&mount_cv);
	mutex_exit(&mount_lock);
}

/*
 * The VFS layer is busy with a mount; zones should wait until all
 * mounts are completed to progress.
 */
void
mount_in_progress(void)
{
	mutex_enter(&mount_lock);
	while (mounts_in_progress < 0)
		cv_wait(&mount_cv, &mount_lock);
	mounts_in_progress++;
	mutex_exit(&mount_lock);
}

/*
 * VFS is done with one mount; wake up any waiting block_mounts()
 * callers if this is the last mount.
 */
void
mount_completed(void)
{
	mutex_enter(&mount_lock);
	if (--mounts_in_progress == 0)
		cv_broadcast(&mount_cv);
	mutex_exit(&mount_lock);
}

/*
 * ZSD routines.
 *
 * Zone Specific Data (ZSD) is modeled after Thread Specific Data as
 * defined by the pthread_key_create() and related interfaces.
 *
 * Kernel subsystems may register one or more data items and/or
 * callbacks to be executed when a zone is created, shutdown, or
 * destroyed.
 *
 * Unlike the thread counterpart, destructor callbacks will be executed
 * even if the data pointer is NULL and/or there are no constructor
 * callbacks, so it is the responsibility of such callbacks to check for
 * NULL data values if necessary.
 *
 * The locking strategy and overall picture is as follows:
 *
 * When someone calls zone_key_create(), a template ZSD entry is added to the
 * global list "zsd_registered_keys", protected by zsd_key_lock.  The
 * constructor callback is called immediately on all existing zones, and a
 * copy of the ZSD entry added to the per-zone zone_zsd list (protected by
 * zone_lock).  As this operation requires the list of zones, the list of
 * registered keys, and the per-zone list of ZSD entries to remain constant
 * throughout the entire operation, it must grab zonehash_lock, zone_lock for
 * all existing zones, and zsd_key_lock, in that order.  Similar locking is
 * needed when zone_key_delete() is called.  It is thus sufficient to hold
 * zsd_key_lock *or* zone_lock to prevent additions to or removals from the
 * per-zone zone_zsd list.
 *
 * Note that this implementation does not make a copy of the ZSD entry if a
 * constructor callback is not provided.  A zone_getspecific() on such an
 * uninitialized ZSD entry will return NULL.
 *
 * When new zones are created constructor callbacks for all registered ZSD
 * entries will be called.
 *
 * The framework does not provide any locking around zone_getspecific() and
 * zone_setspecific() apart from that needed for internal consistency, so
 * callers interested in atomic "test-and-set" semantics will need to provide
 * their own locking.
 */
void
zone_key_create(zone_key_t *keyp, void *(*create)(zoneid_t),
    void (*shutdown)(zoneid_t, void *), void (*destroy)(zoneid_t, void *))
{
	struct zsd_entry *zsdp;
	struct zsd_entry *t;
	struct zone *zone;

	zsdp = kmem_alloc(sizeof (*zsdp), KM_SLEEP);
	zsdp->zsd_data = NULL;
	zsdp->zsd_create = create;
	zsdp->zsd_shutdown = shutdown;
	zsdp->zsd_destroy = destroy;

	mutex_enter(&zonehash_lock);	/* stop the world */
	for (zone = list_head(&zone_active); zone != NULL;
	    zone = list_next(&zone_active, zone))
		mutex_enter(&zone->zone_lock);	/* lock all zones */

	mutex_enter(&zsd_key_lock);
	*keyp = zsdp->zsd_key = ++zsd_keyval;
	ASSERT(zsd_keyval != 0);
	list_insert_tail(&zsd_registered_keys, zsdp);
	mutex_exit(&zsd_key_lock);

	if (create != NULL) {
		for (zone = list_head(&zone_active); zone != NULL;
		    zone = list_next(&zone_active, zone)) {
			t = kmem_alloc(sizeof (*t), KM_SLEEP);
			t->zsd_key = *keyp;
			t->zsd_data = (*create)(zone->zone_id);
			t->zsd_create = create;
			t->zsd_shutdown = shutdown;
			t->zsd_destroy = destroy;
			list_insert_tail(&zone->zone_zsd, t);
		}
	}
	for (zone = list_head(&zone_active); zone != NULL;
	    zone = list_next(&zone_active, zone))
		mutex_exit(&zone->zone_lock);
	mutex_exit(&zonehash_lock);
}

/*
 * Helper function to find the zsd_entry associated with the key in the
 * given list.
 */
static struct zsd_entry *
zsd_find(list_t *l, zone_key_t key)
{
	struct zsd_entry *zsd;

	for (zsd = list_head(l); zsd != NULL; zsd = list_next(l, zsd)) {
		if (zsd->zsd_key == key) {
			/*
			 * Move to head of list to keep list in MRU order.
			 */
			if (zsd != list_head(l)) {
				list_remove(l, zsd);
				list_insert_head(l, zsd);
			}
			return (zsd);
		}
	}
	return (NULL);
}

/*
 * Function called when a module is being unloaded, or otherwise wishes
 * to unregister its ZSD key and callbacks.
 */
int
zone_key_delete(zone_key_t key)
{
	struct zsd_entry *zsdp = NULL;
	zone_t *zone;

	mutex_enter(&zonehash_lock);	/* Zone create/delete waits for us */
	for (zone = list_head(&zone_active); zone != NULL;
	    zone = list_next(&zone_active, zone))
		mutex_enter(&zone->zone_lock);	/* lock all zones */

	mutex_enter(&zsd_key_lock);
	zsdp = zsd_find(&zsd_registered_keys, key);
	if (zsdp == NULL)
		goto notfound;
	list_remove(&zsd_registered_keys, zsdp);
	mutex_exit(&zsd_key_lock);

	for (zone = list_head(&zone_active); zone != NULL;
	    zone = list_next(&zone_active, zone)) {
		struct zsd_entry *del;
		void *data;

		if (!(zone->zone_flags & ZF_DESTROYED)) {
			del = zsd_find(&zone->zone_zsd, key);
			if (del != NULL) {
				data = del->zsd_data;
				ASSERT(del->zsd_shutdown == zsdp->zsd_shutdown);
				ASSERT(del->zsd_destroy == zsdp->zsd_destroy);
				list_remove(&zone->zone_zsd, del);
				kmem_free(del, sizeof (*del));
			} else {
				data = NULL;
			}
			if (zsdp->zsd_shutdown)
				zsdp->zsd_shutdown(zone->zone_id, data);
			if (zsdp->zsd_destroy)
				zsdp->zsd_destroy(zone->zone_id, data);
		}
		mutex_exit(&zone->zone_lock);
	}
	mutex_exit(&zonehash_lock);
	kmem_free(zsdp, sizeof (*zsdp));
	return (0);

notfound:
	mutex_exit(&zsd_key_lock);
	for (zone = list_head(&zone_active); zone != NULL;
	    zone = list_next(&zone_active, zone))
		mutex_exit(&zone->zone_lock);
	mutex_exit(&zonehash_lock);
	return (-1);
}

/*
 * ZSD counterpart of pthread_setspecific().
 */
int
zone_setspecific(zone_key_t key, zone_t *zone, const void *data)
{
	struct zsd_entry *t;
	struct zsd_entry *zsdp = NULL;

	mutex_enter(&zone->zone_lock);
	t = zsd_find(&zone->zone_zsd, key);
	if (t != NULL) {
		/*
		 * Replace old value with new
		 */
		t->zsd_data = (void *)data;
		mutex_exit(&zone->zone_lock);
		return (0);
	}
	/*
	 * If there was no previous value, go through the list of registered
	 * keys.
	 *
	 * We avoid grabbing zsd_key_lock until we are sure we need it; this is
	 * necessary for shutdown callbacks to be able to execute without fear
	 * of deadlock.
	 */
	mutex_enter(&zsd_key_lock);
	zsdp = zsd_find(&zsd_registered_keys, key);
	if (zsdp == NULL) { 	/* Key was not registered */
		mutex_exit(&zsd_key_lock);
		mutex_exit(&zone->zone_lock);
		return (-1);
	}

	/*
	 * Add a zsd_entry to this zone, using the template we just retrieved
	 * to initialize the constructor and destructor(s).
	 */
	t = kmem_alloc(sizeof (*t), KM_SLEEP);
	t->zsd_key = key;
	t->zsd_data = (void *)data;
	t->zsd_create = zsdp->zsd_create;
	t->zsd_shutdown = zsdp->zsd_shutdown;
	t->zsd_destroy = zsdp->zsd_destroy;
	list_insert_tail(&zone->zone_zsd, t);
	mutex_exit(&zsd_key_lock);
	mutex_exit(&zone->zone_lock);
	return (0);
}

/*
 * ZSD counterpart of pthread_getspecific().
 */
void *
zone_getspecific(zone_key_t key, zone_t *zone)
{
	struct zsd_entry *t;
	void *data;

	mutex_enter(&zone->zone_lock);
	t = zsd_find(&zone->zone_zsd, key);
	data = (t == NULL ? NULL : t->zsd_data);
	mutex_exit(&zone->zone_lock);
	return (data);
}

/*
 * Function used to initialize a zone's list of ZSD callbacks and data
 * when the zone is being created.  The callbacks are initialized from
 * the template list (zsd_registered_keys), and the constructor
 * callback executed (if one exists).
 *
 * This is called before the zone is made publicly available, hence no
 * need to grab zone_lock.
 *
 * Although we grab and release zsd_key_lock, new entries cannot be
 * added to or removed from the zsd_registered_keys list until we
 * release zonehash_lock, so there isn't a window for a
 * zone_key_create() to come in after we've dropped zsd_key_lock but
 * before the zone is added to the zone list, such that the constructor
 * callbacks aren't executed for the new zone.
 */
static void
zone_zsd_configure(zone_t *zone)
{
	struct zsd_entry *zsdp;
	struct zsd_entry *t;
	zoneid_t zoneid = zone->zone_id;

	ASSERT(MUTEX_HELD(&zonehash_lock));
	ASSERT(list_head(&zone->zone_zsd) == NULL);
	mutex_enter(&zsd_key_lock);
	for (zsdp = list_head(&zsd_registered_keys); zsdp != NULL;
	    zsdp = list_next(&zsd_registered_keys, zsdp)) {
		if (zsdp->zsd_create != NULL) {
			t = kmem_alloc(sizeof (*t), KM_SLEEP);
			t->zsd_key = zsdp->zsd_key;
			t->zsd_create = zsdp->zsd_create;
			t->zsd_data = (*t->zsd_create)(zoneid);
			t->zsd_shutdown = zsdp->zsd_shutdown;
			t->zsd_destroy = zsdp->zsd_destroy;
			list_insert_tail(&zone->zone_zsd, t);
		}
	}
	mutex_exit(&zsd_key_lock);
}

enum zsd_callback_type { ZSD_CREATE, ZSD_SHUTDOWN, ZSD_DESTROY };

/*
 * Helper function to execute shutdown or destructor callbacks.
 */
static void
zone_zsd_callbacks(zone_t *zone, enum zsd_callback_type ct)
{
	struct zsd_entry *zsdp;
	struct zsd_entry *t;
	zoneid_t zoneid = zone->zone_id;

	ASSERT(ct == ZSD_SHUTDOWN || ct == ZSD_DESTROY);
	ASSERT(ct != ZSD_SHUTDOWN || zone_status_get(zone) >= ZONE_IS_EMPTY);
	ASSERT(ct != ZSD_DESTROY || zone_status_get(zone) >= ZONE_IS_DOWN);

	mutex_enter(&zone->zone_lock);
	if (ct == ZSD_DESTROY) {
		if (zone->zone_flags & ZF_DESTROYED) {
			/*
			 * Make sure destructors are only called once.
			 */
			mutex_exit(&zone->zone_lock);
			return;
		}
		zone->zone_flags |= ZF_DESTROYED;
	}
	mutex_exit(&zone->zone_lock);

	/*
	 * Both zsd_key_lock and zone_lock need to be held in order to add or
	 * remove a ZSD key, (either globally as part of
	 * zone_key_create()/zone_key_delete(), or on a per-zone basis, as is
	 * possible through zone_setspecific()), so it's sufficient to hold
	 * zsd_key_lock here.
	 *
	 * This is a good thing, since we don't want to recursively try to grab
	 * zone_lock if a callback attempts to do something like a crfree() or
	 * zone_rele().
	 */
	mutex_enter(&zsd_key_lock);
	for (zsdp = list_head(&zsd_registered_keys); zsdp != NULL;
	    zsdp = list_next(&zsd_registered_keys, zsdp)) {
		zone_key_t key = zsdp->zsd_key;

		/* Skip if no callbacks registered */
		if (ct == ZSD_SHUTDOWN && zsdp->zsd_shutdown == NULL)
			continue;
		if (ct == ZSD_DESTROY && zsdp->zsd_destroy == NULL)
			continue;
		/*
		 * Call the callback with the zone-specific data if we can find
		 * any, otherwise with NULL.
		 */
		t = zsd_find(&zone->zone_zsd, key);
		if (t != NULL) {
			if (ct == ZSD_SHUTDOWN) {
				t->zsd_shutdown(zoneid, t->zsd_data);
			} else {
				ASSERT(ct == ZSD_DESTROY);
				t->zsd_destroy(zoneid, t->zsd_data);
			}
		} else {
			if (ct == ZSD_SHUTDOWN) {
				zsdp->zsd_shutdown(zoneid, NULL);
			} else {
				ASSERT(ct == ZSD_DESTROY);
				zsdp->zsd_destroy(zoneid, NULL);
			}
		}
	}
	mutex_exit(&zsd_key_lock);
}

/*
 * Called when the zone is going away; free ZSD-related memory, and
 * destroy the zone_zsd list.
 */
static void
zone_free_zsd(zone_t *zone)
{
	struct zsd_entry *t, *next;

	/*
	 * Free all the zsd_entry's we had on this zone.
	 */
	for (t = list_head(&zone->zone_zsd); t != NULL; t = next) {
		next = list_next(&zone->zone_zsd, t);
		list_remove(&zone->zone_zsd, t);
		kmem_free(t, sizeof (*t));
	}
	list_destroy(&zone->zone_zsd);
}

/*
 * Frees memory associated with the zone dataset list.
 */
static void
zone_free_datasets(zone_t *zone)
{
	zone_dataset_t *t, *next;

	for (t = list_head(&zone->zone_datasets); t != NULL; t = next) {
		next = list_next(&zone->zone_datasets, t);
		list_remove(&zone->zone_datasets, t);
		kmem_free(t->zd_dataset, strlen(t->zd_dataset) + 1);
		kmem_free(t, sizeof (*t));
	}
	list_destroy(&zone->zone_datasets);
}

/*
 * zone.cpu-shares resource control support.
 */
/*ARGSUSED*/
static rctl_qty_t
zone_cpu_shares_usage(rctl_t *rctl, struct proc *p)
{
	ASSERT(MUTEX_HELD(&p->p_lock));
	return (p->p_zone->zone_shares);
}

/*ARGSUSED*/
static int
zone_cpu_shares_set(rctl_t *rctl, struct proc *p, rctl_entity_p_t *e,
    rctl_qty_t nv)
{
	ASSERT(MUTEX_HELD(&p->p_lock));
	ASSERT(e->rcep_t == RCENTITY_ZONE);
	if (e->rcep_p.zone == NULL)
		return (0);

	e->rcep_p.zone->zone_shares = nv;
	return (0);
}

static rctl_ops_t zone_cpu_shares_ops = {
	rcop_no_action,
	zone_cpu_shares_usage,
	zone_cpu_shares_set,
	rcop_no_test
};

/*ARGSUSED*/
static rctl_qty_t
zone_lwps_usage(rctl_t *r, proc_t *p)
{
	rctl_qty_t nlwps;
	zone_t *zone = p->p_zone;

	ASSERT(MUTEX_HELD(&p->p_lock));

	mutex_enter(&zone->zone_nlwps_lock);
	nlwps = zone->zone_nlwps;
	mutex_exit(&zone->zone_nlwps_lock);

	return (nlwps);
}

/*ARGSUSED*/
static int
zone_lwps_test(rctl_t *r, proc_t *p, rctl_entity_p_t *e, rctl_val_t *rcntl,
    rctl_qty_t incr, uint_t flags)
{
	rctl_qty_t nlwps;

	ASSERT(MUTEX_HELD(&p->p_lock));
	ASSERT(e->rcep_t == RCENTITY_ZONE);
	if (e->rcep_p.zone == NULL)
		return (0);
	ASSERT(MUTEX_HELD(&(e->rcep_p.zone->zone_nlwps_lock)));
	nlwps = e->rcep_p.zone->zone_nlwps;

	if (nlwps + incr > rcntl->rcv_value)
		return (1);

	return (0);
}

/*ARGSUSED*/
static int
zone_lwps_set(rctl_t *rctl, struct proc *p, rctl_entity_p_t *e, rctl_qty_t nv) {

	ASSERT(MUTEX_HELD(&p->p_lock));
	ASSERT(e->rcep_t == RCENTITY_ZONE);
	if (e->rcep_p.zone == NULL)
		return (0);
	e->rcep_p.zone->zone_nlwps_ctl = nv;
	return (0);
}

static rctl_ops_t zone_lwps_ops = {
	rcop_no_action,
	zone_lwps_usage,
	zone_lwps_set,
	zone_lwps_test,
};

/*
 * Helper function to brand the zone with a unique ID.
 */
static void
zone_uniqid(zone_t *zone)
{
	static uint64_t uniqid = 0;

	ASSERT(MUTEX_HELD(&zonehash_lock));
	zone->zone_uniqid = uniqid++;
}

/*
 * Returns a held pointer to the "kcred" for the specified zone.
 */
struct cred *
zone_get_kcred(zoneid_t zoneid)
{
	zone_t *zone;
	cred_t *cr;

	if ((zone = zone_find_by_id(zoneid)) == NULL)
		return (NULL);
	cr = zone->zone_kcred;
	crhold(cr);
	zone_rele(zone);
	return (cr);
}

/*
 * Called very early on in boot to initialize the ZSD list so that
 * zone_key_create() can be called before zone_init().  It also initializes
 * portions of zone0 which may be used before zone_init() is called.  The
 * variable "global_zone" will be set when zone0 is fully initialized by
 * zone_init().
 */
void
zone_zsd_init(void)
{
	mutex_init(&zonehash_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&zsd_key_lock, NULL, MUTEX_DEFAULT, NULL);
	list_create(&zsd_registered_keys, sizeof (struct zsd_entry),
	    offsetof(struct zsd_entry, zsd_linkage));
	list_create(&zone_active, sizeof (zone_t),
	    offsetof(zone_t, zone_linkage));
	list_create(&zone_deathrow, sizeof (zone_t),
	    offsetof(zone_t, zone_linkage));

	mutex_init(&zone0.zone_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&zone0.zone_nlwps_lock, NULL, MUTEX_DEFAULT, NULL);
	zone0.zone_shares = 1;
	zone0.zone_nlwps_ctl = INT_MAX;
	zone0.zone_name = GLOBAL_ZONENAME;
	zone0.zone_nodename = utsname.nodename;
	zone0.zone_domain = srpc_domain;
	zone0.zone_ref = 1;
	zone0.zone_id = GLOBAL_ZONEID;
	zone0.zone_status = ZONE_IS_RUNNING;
	zone0.zone_rootpath = "/";
	zone0.zone_rootpathlen = 2;
	zone0.zone_psetid = ZONE_PS_INVAL;
	zone0.zone_ncpus = 0;
	zone0.zone_ncpus_online = 0;
	zone0.zone_proc_initpid = 1;
	list_create(&zone0.zone_zsd, sizeof (struct zsd_entry),
	    offsetof(struct zsd_entry, zsd_linkage));
	list_insert_head(&zone_active, &zone0);

	/*
	 * The root filesystem is not mounted yet, so zone_rootvp cannot be set
	 * to anything meaningful.  It is assigned to be 'rootdir' in
	 * vfs_mountroot().
	 */
	zone0.zone_rootvp = NULL;
	zone0.zone_vfslist = NULL;
	zone0.zone_bootargs = NULL;
	zone0.zone_privset = kmem_alloc(sizeof (priv_set_t), KM_SLEEP);
	/*
	 * The global zone has all privileges
	 */
	priv_fillset(zone0.zone_privset);
	/*
	 * Add p0 to the global zone
	 */
	zone0.zone_zsched = &p0;
	p0.p_zone = &zone0;
}

/*
 * Called by main() to initialize the zones framework.
 */
void
zone_init(void)
{
	rctl_dict_entry_t *rde;
	rctl_val_t *dval;
	rctl_set_t *set;
	rctl_alloc_gp_t *gp;
	rctl_entity_p_t e;

	ASSERT(curproc == &p0);

	/*
	 * Create ID space for zone IDs.  ID 0 is reserved for the
	 * global zone.
	 */
	zoneid_space = id_space_create("zoneid_space", 1, MAX_ZONEID);

	/*
	 * Initialize generic zone resource controls, if any.
	 */
	rc_zone_cpu_shares = rctl_register("zone.cpu-shares",
	    RCENTITY_ZONE, RCTL_GLOBAL_SIGNAL_NEVER | RCTL_GLOBAL_DENY_NEVER |
	    RCTL_GLOBAL_NOBASIC |
	    RCTL_GLOBAL_COUNT, FSS_MAXSHARES, FSS_MAXSHARES,
	    &zone_cpu_shares_ops);

	rc_zone_nlwps = rctl_register("zone.max-lwps", RCENTITY_ZONE,
	    RCTL_GLOBAL_NOACTION | RCTL_GLOBAL_NOBASIC | RCTL_GLOBAL_COUNT,
	    INT_MAX, INT_MAX, &zone_lwps_ops);
	/*
	 * Create a rctl_val with PRIVILEGED, NOACTION, value = 1.  Then attach
	 * this at the head of the rctl_dict_entry for ``zone.cpu-shares''.
	 */
	dval = kmem_cache_alloc(rctl_val_cache, KM_SLEEP);
	bzero(dval, sizeof (rctl_val_t));
	dval->rcv_value = 1;
	dval->rcv_privilege = RCPRIV_PRIVILEGED;
	dval->rcv_flagaction = RCTL_LOCAL_NOACTION;
	dval->rcv_action_recip_pid = -1;

	rde = rctl_dict_lookup("zone.cpu-shares");
	(void) rctl_val_list_insert(&rde->rcd_default_value, dval);

	/*
	 * Initialize the ``global zone''.
	 */
	set = rctl_set_create();
	gp = rctl_set_init_prealloc(RCENTITY_ZONE);
	mutex_enter(&p0.p_lock);
	e.rcep_p.zone = &zone0;
	e.rcep_t = RCENTITY_ZONE;
	zone0.zone_rctls = rctl_set_init(RCENTITY_ZONE, &p0, &e, set,
	    gp);

	zone0.zone_nlwps = p0.p_lwpcnt;
	zone0.zone_ntasks = 1;
	mutex_exit(&p0.p_lock);
	rctl_prealloc_destroy(gp);
	/*
	 * pool_default hasn't been initialized yet, so we let pool_init() take
	 * care of making the global zone is in the default pool.
	 */
	mutex_enter(&zonehash_lock);
	zone_uniqid(&zone0);
	ASSERT(zone0.zone_uniqid == GLOBAL_ZONEUNIQID);
	mutex_exit(&zonehash_lock);
	zonehashbyid = mod_hash_create_idhash("zone_by_id", zone_hash_size,
	    mod_hash_null_valdtor);
	zonehashbyname = mod_hash_create_strhash("zone_by_name",
	    zone_hash_size, mod_hash_null_valdtor);
	zonecount = 1;

	(void) mod_hash_insert(zonehashbyid, (mod_hash_key_t)GLOBAL_ZONEID,
	    (mod_hash_val_t)&zone0);
	(void) mod_hash_insert(zonehashbyname, (mod_hash_key_t)zone0.zone_name,
	    (mod_hash_val_t)&zone0);
	/*
	 * We avoid setting zone_kcred until now, since kcred is initialized
	 * sometime after zone_zsd_init() and before zone_init().
	 */
	zone0.zone_kcred = kcred;
	/*
	 * The global zone is fully initialized (except for zone_rootvp which
	 * will be set when the root filesystem is mounted).
	 */
	global_zone = &zone0;
}

static void
zone_free(zone_t *zone)
{
	ASSERT(zone != global_zone);
	ASSERT(zone->zone_ntasks == 0);
	ASSERT(zone->zone_nlwps == 0);
	ASSERT(zone->zone_cred_ref == 0);
	ASSERT(zone->zone_kcred == NULL);
	ASSERT(zone_status_get(zone) == ZONE_IS_DEAD ||
	    zone_status_get(zone) == ZONE_IS_UNINITIALIZED);

	/* remove from deathrow list */
	if (zone_status_get(zone) == ZONE_IS_DEAD) {
		ASSERT(zone->zone_ref == 0);
		mutex_enter(&zone_deathrow_lock);
		list_remove(&zone_deathrow, zone);
		mutex_exit(&zone_deathrow_lock);
	}

	zone_free_zsd(zone);
	zone_free_datasets(zone);

	if (zone->zone_rootvp != NULL)
		VN_RELE(zone->zone_rootvp);
	if (zone->zone_rootpath)
		kmem_free(zone->zone_rootpath, zone->zone_rootpathlen);
	if (zone->zone_name != NULL)
		kmem_free(zone->zone_name, ZONENAME_MAX);
	if (zone->zone_nodename != NULL)
		kmem_free(zone->zone_nodename, _SYS_NMLN);
	if (zone->zone_domain != NULL)
		kmem_free(zone->zone_domain, _SYS_NMLN);
	if (zone->zone_privset != NULL)
		kmem_free(zone->zone_privset, sizeof (priv_set_t));
	if (zone->zone_rctls != NULL)
		rctl_set_free(zone->zone_rctls);
	if (zone->zone_bootargs != NULL)
		kmem_free(zone->zone_bootargs, ZONEBOOTARGS_MAX);
	id_free(zoneid_space, zone->zone_id);
	mutex_destroy(&zone->zone_lock);
	cv_destroy(&zone->zone_cv);
	kmem_free(zone, sizeof (zone_t));
}

/*
 * See block comment at the top of this file for information about zone
 * status values.
 */
/*
 * Convenience function for setting zone status.
 */
static void
zone_status_set(zone_t *zone, zone_status_t status)
{
	ASSERT(MUTEX_HELD(&zone_status_lock));
	ASSERT(status > ZONE_MIN_STATE && status <= ZONE_MAX_STATE &&
	    status >= zone_status_get(zone));
	zone->zone_status = status;
	cv_broadcast(&zone->zone_cv);
}

/*
 * Public function to retrieve the zone status.  The zone status may
 * change after it is retrieved.
 */
zone_status_t
zone_status_get(zone_t *zone)
{
	return (zone->zone_status);
}

static int
zone_set_bootargs(zone_t *zone, const char *zone_bootargs)
{
	char *bootargs = kmem_zalloc(ZONEBOOTARGS_MAX, KM_SLEEP);
	size_t len;
	int err;

	err = copyinstr(zone_bootargs, bootargs, ZONEBOOTARGS_MAX - 1, &len);
	if (err != 0) {
		kmem_free(bootargs, ZONEBOOTARGS_MAX);
		return (err);	/* EFAULT or ENAMETOOLONG */
	}
	bootargs[len] = '\0';

	ASSERT(zone->zone_bootargs == NULL);
	zone->zone_bootargs = bootargs;
	return (0);
}

/*
 * Block indefinitely waiting for (zone_status >= status)
 */
void
zone_status_wait(zone_t *zone, zone_status_t status)
{
	ASSERT(status > ZONE_MIN_STATE && status <= ZONE_MAX_STATE);

	mutex_enter(&zone_status_lock);
	while (zone->zone_status < status) {
		cv_wait(&zone->zone_cv, &zone_status_lock);
	}
	mutex_exit(&zone_status_lock);
}

/*
 * Private CPR-safe version of zone_status_wait().
 */
static void
zone_status_wait_cpr(zone_t *zone, zone_status_t status, char *str)
{
	callb_cpr_t cprinfo;

	ASSERT(status > ZONE_MIN_STATE && status <= ZONE_MAX_STATE);

	CALLB_CPR_INIT(&cprinfo, &zone_status_lock, callb_generic_cpr,
	    str);
	mutex_enter(&zone_status_lock);
	while (zone->zone_status < status) {
		CALLB_CPR_SAFE_BEGIN(&cprinfo);
		cv_wait(&zone->zone_cv, &zone_status_lock);
		CALLB_CPR_SAFE_END(&cprinfo, &zone_status_lock);
	}
	/*
	 * zone_status_lock is implicitly released by the following.
	 */
	CALLB_CPR_EXIT(&cprinfo);
}

/*
 * Block until zone enters requested state or signal is received.  Return (0)
 * if signaled, non-zero otherwise.
 */
int
zone_status_wait_sig(zone_t *zone, zone_status_t status)
{
	ASSERT(status > ZONE_MIN_STATE && status <= ZONE_MAX_STATE);

	mutex_enter(&zone_status_lock);
	while (zone->zone_status < status) {
		if (!cv_wait_sig(&zone->zone_cv, &zone_status_lock)) {
			mutex_exit(&zone_status_lock);
			return (0);
		}
	}
	mutex_exit(&zone_status_lock);
	return (1);
}

/*
 * Block until the zone enters the requested state or the timeout expires,
 * whichever happens first.  Return (-1) if operation timed out, time remaining
 * otherwise.
 */
clock_t
zone_status_timedwait(zone_t *zone, clock_t tim, zone_status_t status)
{
	clock_t timeleft = 0;

	ASSERT(status > ZONE_MIN_STATE && status <= ZONE_MAX_STATE);

	mutex_enter(&zone_status_lock);
	while (zone->zone_status < status && timeleft != -1) {
		timeleft = cv_timedwait(&zone->zone_cv, &zone_status_lock, tim);
	}
	mutex_exit(&zone_status_lock);
	return (timeleft);
}

/*
 * Block until the zone enters the requested state, the current process is
 * signaled,  or the timeout expires, whichever happens first.  Return (-1) if
 * operation timed out, 0 if signaled, time remaining otherwise.
 */
clock_t
zone_status_timedwait_sig(zone_t *zone, clock_t tim, zone_status_t status)
{
	clock_t timeleft = tim - lbolt;

	ASSERT(status > ZONE_MIN_STATE && status <= ZONE_MAX_STATE);

	mutex_enter(&zone_status_lock);
	while (zone->zone_status < status) {
		timeleft = cv_timedwait_sig(&zone->zone_cv, &zone_status_lock,
		    tim);
		if (timeleft <= 0)
			break;
	}
	mutex_exit(&zone_status_lock);
	return (timeleft);
}

/*
 * Zones have two reference counts: one for references from credential
 * structures (zone_cred_ref), and one (zone_ref) for everything else.
 * This is so we can allow a zone to be rebooted while there are still
 * outstanding cred references, since certain drivers cache dblks (which
 * implicitly results in cached creds).  We wait for zone_ref to drop to
 * 0 (actually 1), but not zone_cred_ref.  The zone structure itself is
 * later freed when the zone_cred_ref drops to 0, though nothing other
 * than the zone id and privilege set should be accessed once the zone
 * is "dead".
 *
 * A debugging flag, zone_wait_for_cred, can be set to a non-zero value
 * to force halt/reboot to block waiting for the zone_cred_ref to drop
 * to 0.  This can be useful to flush out other sources of cached creds
 * that may be less innocuous than the driver case.
 */

int zone_wait_for_cred = 0;

static void
zone_hold_locked(zone_t *z)
{
	ASSERT(MUTEX_HELD(&z->zone_lock));
	z->zone_ref++;
	ASSERT(z->zone_ref != 0);
}

void
zone_hold(zone_t *z)
{
	mutex_enter(&z->zone_lock);
	zone_hold_locked(z);
	mutex_exit(&z->zone_lock);
}

/*
 * If the non-cred ref count drops to 1 and either the cred ref count
 * is 0 or we aren't waiting for cred references, the zone is ready to
 * be destroyed.
 */
#define	ZONE_IS_UNREF(zone)	((zone)->zone_ref == 1 && \
	    (!zone_wait_for_cred || (zone)->zone_cred_ref == 0))

void
zone_rele(zone_t *z)
{
	boolean_t wakeup;

	mutex_enter(&z->zone_lock);
	ASSERT(z->zone_ref != 0);
	z->zone_ref--;
	if (z->zone_ref == 0 && z->zone_cred_ref == 0) {
		/* no more refs, free the structure */
		mutex_exit(&z->zone_lock);
		zone_free(z);
		return;
	}
	/* signal zone_destroy so the zone can finish halting */
	wakeup = (ZONE_IS_UNREF(z) && zone_status_get(z) >= ZONE_IS_DEAD);
	mutex_exit(&z->zone_lock);

	if (wakeup) {
		/*
		 * Grabbing zonehash_lock here effectively synchronizes with
		 * zone_destroy() to avoid missed signals.
		 */
		mutex_enter(&zonehash_lock);
		cv_broadcast(&zone_destroy_cv);
		mutex_exit(&zonehash_lock);
	}
}

void
zone_cred_hold(zone_t *z)
{
	mutex_enter(&z->zone_lock);
	z->zone_cred_ref++;
	ASSERT(z->zone_cred_ref != 0);
	mutex_exit(&z->zone_lock);
}

void
zone_cred_rele(zone_t *z)
{
	boolean_t wakeup;

	mutex_enter(&z->zone_lock);
	ASSERT(z->zone_cred_ref != 0);
	z->zone_cred_ref--;
	if (z->zone_ref == 0 && z->zone_cred_ref == 0) {
		/* no more refs, free the structure */
		mutex_exit(&z->zone_lock);
		zone_free(z);
		return;
	}
	/*
	 * If zone_destroy is waiting for the cred references to drain
	 * out, and they have, signal it.
	 */
	wakeup = (zone_wait_for_cred && ZONE_IS_UNREF(z) &&
	    zone_status_get(z) >= ZONE_IS_DEAD);
	mutex_exit(&z->zone_lock);

	if (wakeup) {
		/*
		 * Grabbing zonehash_lock here effectively synchronizes with
		 * zone_destroy() to avoid missed signals.
		 */
		mutex_enter(&zonehash_lock);
		cv_broadcast(&zone_destroy_cv);
		mutex_exit(&zonehash_lock);
	}
}

void
zone_task_hold(zone_t *z)
{
	mutex_enter(&z->zone_lock);
	z->zone_ntasks++;
	ASSERT(z->zone_ntasks != 0);
	mutex_exit(&z->zone_lock);
}

void
zone_task_rele(zone_t *zone)
{
	uint_t refcnt;

	mutex_enter(&zone->zone_lock);
	ASSERT(zone->zone_ntasks != 0);
	refcnt = --zone->zone_ntasks;
	if (refcnt > 1)	{	/* Common case */
		mutex_exit(&zone->zone_lock);
		return;
	}
	zone_hold_locked(zone);	/* so we can use the zone_t later */
	mutex_exit(&zone->zone_lock);
	if (refcnt == 1) {
		/*
		 * See if the zone is shutting down.
		 */
		mutex_enter(&zone_status_lock);
		if (zone_status_get(zone) != ZONE_IS_SHUTTING_DOWN) {
			goto out;
		}

		/*
		 * Make sure the ntasks didn't change since we
		 * dropped zone_lock.
		 */
		mutex_enter(&zone->zone_lock);
		if (refcnt != zone->zone_ntasks) {
			mutex_exit(&zone->zone_lock);
			goto out;
		}
		mutex_exit(&zone->zone_lock);

		/*
		 * No more user processes in the zone.  The zone is empty.
		 */
		zone_status_set(zone, ZONE_IS_EMPTY);
		goto out;
	}

	ASSERT(refcnt == 0);
	/*
	 * zsched has exited; the zone is dead.
	 */
	zone->zone_zsched = NULL;		/* paranoia */
	mutex_enter(&zone_status_lock);
	zone_status_set(zone, ZONE_IS_DEAD);
out:
	mutex_exit(&zone_status_lock);
	zone_rele(zone);
}

zoneid_t
getzoneid(void)
{
	return (curproc->p_zone->zone_id);
}

/*
 * Internal versions of zone_find_by_*().  These don't zone_hold() or
 * check the validity of a zone's state.
 */
static zone_t *
zone_find_all_by_id(zoneid_t zoneid)
{
	mod_hash_val_t hv;
	zone_t *zone = NULL;

	ASSERT(MUTEX_HELD(&zonehash_lock));

	if (mod_hash_find(zonehashbyid,
	    (mod_hash_key_t)(uintptr_t)zoneid, &hv) == 0)
		zone = (zone_t *)hv;
	return (zone);
}

static zone_t *
zone_find_all_by_name(char *name)
{
	mod_hash_val_t hv;
	zone_t *zone = NULL;

	ASSERT(MUTEX_HELD(&zonehash_lock));

	if (mod_hash_find(zonehashbyname, (mod_hash_key_t)name, &hv) == 0)
		zone = (zone_t *)hv;
	return (zone);
}

/*
 * Public interface for looking up a zone by zoneid.  Only returns the zone if
 * it is fully initialized, and has not yet begun the zone_destroy() sequence.
 * Caller must call zone_rele() once it is done with the zone.
 *
 * The zone may begin the zone_destroy() sequence immediately after this
 * function returns, but may be safely used until zone_rele() is called.
 */
zone_t *
zone_find_by_id(zoneid_t zoneid)
{
	zone_t *zone;
	zone_status_t status;

	mutex_enter(&zonehash_lock);
	if ((zone = zone_find_all_by_id(zoneid)) == NULL) {
		mutex_exit(&zonehash_lock);
		return (NULL);
	}
	status = zone_status_get(zone);
	if (status < ZONE_IS_READY || status > ZONE_IS_DOWN) {
		/*
		 * For all practical purposes the zone doesn't exist.
		 */
		mutex_exit(&zonehash_lock);
		return (NULL);
	}
	zone_hold(zone);
	mutex_exit(&zonehash_lock);
	return (zone);
}

/*
 * Similar to zone_find_by_id, but using zone name as the key.
 */
zone_t *
zone_find_by_name(char *name)
{
	zone_t *zone;
	zone_status_t status;

	mutex_enter(&zonehash_lock);
	if ((zone = zone_find_all_by_name(name)) == NULL) {
		mutex_exit(&zonehash_lock);
		return (NULL);
	}
	status = zone_status_get(zone);
	if (status < ZONE_IS_READY || status > ZONE_IS_DOWN) {
		/*
		 * For all practical purposes the zone doesn't exist.
		 */
		mutex_exit(&zonehash_lock);
		return (NULL);
	}
	zone_hold(zone);
	mutex_exit(&zonehash_lock);
	return (zone);
}

/*
 * Similar to zone_find_by_id(), using the path as a key.  For instance,
 * if there is a zone "foo" rooted at /foo/root, and the path argument
 * is "/foo/root/proc", it will return the held zone_t corresponding to
 * zone "foo".
 *
 * zone_find_by_path() always returns a non-NULL value, since at the
 * very least every path will be contained in the global zone.
 *
 * As with the other zone_find_by_*() functions, the caller is
 * responsible for zone_rele()ing the return value of this function.
 */
zone_t *
zone_find_by_path(const char *path)
{
	zone_t *zone;
	zone_t *zret = NULL;
	zone_status_t status;

	if (path == NULL) {
		/*
		 * Call from rootconf().
		 */
		zone_hold(global_zone);
		return (global_zone);
	}
	ASSERT(*path == '/');
	mutex_enter(&zonehash_lock);
	for (zone = list_head(&zone_active); zone != NULL;
	    zone = list_next(&zone_active, zone)) {
		if (ZONE_PATH_VISIBLE(path, zone))
			zret = zone;
	}
	ASSERT(zret != NULL);
	status = zone_status_get(zret);
	if (status < ZONE_IS_READY || status > ZONE_IS_DOWN) {
		/*
		 * Zone practically doesn't exist.
		 */
		zret = global_zone;
	}
	zone_hold(zret);
	mutex_exit(&zonehash_lock);
	return (zret);
}

/*
 * Get the number of cpus visible to this zone.  The system-wide global
 * 'ncpus' is returned if pools are disabled, the caller is in the
 * global zone, or a NULL zone argument is passed in.
 */
int
zone_ncpus_get(zone_t *zone)
{
	int myncpus = zone == NULL ? 0 : zone->zone_ncpus;

	return (myncpus != 0 ? myncpus : ncpus);
}

/*
 * Get the number of online cpus visible to this zone.  The system-wide
 * global 'ncpus_online' is returned if pools are disabled, the caller
 * is in the global zone, or a NULL zone argument is passed in.
 */
int
zone_ncpus_online_get(zone_t *zone)
{
	int myncpus_online = zone == NULL ? 0 : zone->zone_ncpus_online;

	return (myncpus_online != 0 ? myncpus_online : ncpus_online);
}

/*
 * Return the pool to which the zone is currently bound.
 */
pool_t *
zone_pool_get(zone_t *zone)
{
	ASSERT(pool_lock_held());

	return (zone->zone_pool);
}

/*
 * Set the zone's pool pointer and update the zone's visibility to match
 * the resources in the new pool.
 */
void
zone_pool_set(zone_t *zone, pool_t *pool)
{
	ASSERT(pool_lock_held());
	ASSERT(MUTEX_HELD(&cpu_lock));

	zone->zone_pool = pool;
	zone_pset_set(zone, pool->pool_pset->pset_id);
}

/*
 * Return the cached value of the id of the processor set to which the
 * zone is currently bound.  The value will be ZONE_PS_INVAL if the pools
 * facility is disabled.
 */
psetid_t
zone_pset_get(zone_t *zone)
{
	ASSERT(MUTEX_HELD(&cpu_lock));

	return (zone->zone_psetid);
}

/*
 * Set the cached value of the id of the processor set to which the zone
 * is currently bound.  Also update the zone's visibility to match the
 * resources in the new processor set.
 */
void
zone_pset_set(zone_t *zone, psetid_t newpsetid)
{
	psetid_t oldpsetid;

	ASSERT(MUTEX_HELD(&cpu_lock));
	oldpsetid = zone_pset_get(zone);

	if (oldpsetid == newpsetid)
		return;
	/*
	 * Global zone sees all.
	 */
	if (zone != global_zone) {
		zone->zone_psetid = newpsetid;
		if (newpsetid != ZONE_PS_INVAL)
			pool_pset_visibility_add(newpsetid, zone);
		if (oldpsetid != ZONE_PS_INVAL)
			pool_pset_visibility_remove(oldpsetid, zone);
	}
	/*
	 * Disabling pools, so we should start using the global values
	 * for ncpus and ncpus_online.
	 */
	if (newpsetid == ZONE_PS_INVAL) {
		zone->zone_ncpus = 0;
		zone->zone_ncpus_online = 0;
	}
}

/*
 * Walk the list of active zones and issue the provided callback for
 * each of them.
 *
 * Caller must not be holding any locks that may be acquired under
 * zonehash_lock.  See comment at the beginning of the file for a list of
 * common locks and their interactions with zones.
 */
int
zone_walk(int (*cb)(zone_t *, void *), void *data)
{
	zone_t *zone;
	int ret = 0;
	zone_status_t status;

	mutex_enter(&zonehash_lock);
	for (zone = list_head(&zone_active); zone != NULL;
	    zone = list_next(&zone_active, zone)) {
		/*
		 * Skip zones that shouldn't be externally visible.
		 */
		status = zone_status_get(zone);
		if (status < ZONE_IS_READY || status > ZONE_IS_DOWN)
			continue;
		/*
		 * Bail immediately if any callback invocation returns a
		 * non-zero value.
		 */
		ret = (*cb)(zone, data);
		if (ret != 0)
			break;
	}
	mutex_exit(&zonehash_lock);
	return (ret);
}

static int
zone_set_root(zone_t *zone, const char *upath)
{
	vnode_t *vp;
	int trycount;
	int error = 0;
	char *path;
	struct pathname upn, pn;
	size_t pathlen;

	if ((error = pn_get((char *)upath, UIO_USERSPACE, &upn)) != 0)
		return (error);

	pn_alloc(&pn);

	/* prevent infinite loop */
	trycount = 10;
	for (;;) {
		if (--trycount <= 0) {
			error = ESTALE;
			goto out;
		}

		if ((error = lookuppn(&upn, &pn, FOLLOW, NULLVPP, &vp)) == 0) {
			/*
			 * VOP_ACCESS() may cover 'vp' with a new
			 * filesystem, if 'vp' is an autoFS vnode.
			 * Get the new 'vp' if so.
			 */
			if ((error = VOP_ACCESS(vp, VEXEC, 0, CRED())) == 0 &&
			    (vp->v_vfsmountedhere == NULL ||
			    (error = traverse(&vp)) == 0)) {
				pathlen = pn.pn_pathlen + 2;
				path = kmem_alloc(pathlen, KM_SLEEP);
				(void) strncpy(path, pn.pn_path,
				    pn.pn_pathlen + 1);
				path[pathlen - 2] = '/';
				path[pathlen - 1] = '\0';
				pn_free(&pn);
				pn_free(&upn);

				/* Success! */
				break;
			}
			VN_RELE(vp);
		}
		if (error != ESTALE)
			goto out;
	}

	ASSERT(error == 0);
	zone->zone_rootvp = vp;		/* we hold a reference to vp */
	zone->zone_rootpath = path;
	zone->zone_rootpathlen = pathlen;
	return (0);

out:
	pn_free(&pn);
	pn_free(&upn);
	return (error);
}

#define	isalnum(c)	(((c) >= '0' && (c) <= '9') || \
			((c) >= 'a' && (c) <= 'z') || \
			((c) >= 'A' && (c) <= 'Z'))

static int
zone_set_name(zone_t *zone, const char *uname)
{
	char *kname = kmem_zalloc(ZONENAME_MAX, KM_SLEEP);
	size_t len;
	int i, err;

	if ((err = copyinstr(uname, kname, ZONENAME_MAX, &len)) != 0) {
		kmem_free(kname, ZONENAME_MAX);
		return (err);	/* EFAULT or ENAMETOOLONG */
	}

	/* must be less than ZONENAME_MAX */
	if (len == ZONENAME_MAX && kname[ZONENAME_MAX - 1] != '\0') {
		kmem_free(kname, ZONENAME_MAX);
		return (EINVAL);
	}

	/*
	 * Name must start with an alphanumeric and must contain only
	 * alphanumerics, '-', '_' and '.'.
	 */
	if (!isalnum(kname[0])) {
		kmem_free(kname, ZONENAME_MAX);
		return (EINVAL);
	}
	for (i = 1; i < len - 1; i++) {
		if (!isalnum(kname[i]) && kname[i] != '-' && kname[i] != '_' &&
		    kname[i] != '.') {
			kmem_free(kname, ZONENAME_MAX);
			return (EINVAL);
		}
	}

	zone->zone_name = kname;
	return (0);
}

/*
 * Similar to thread_create(), but makes sure the thread is in the appropriate
 * zone's zsched process (curproc->p_zone->zone_zsched) before returning.
 */
/*ARGSUSED*/
kthread_t *
zthread_create(
    caddr_t stk,
    size_t stksize,
    void (*proc)(),
    void *arg,
    size_t len,
    pri_t pri)
{
	kthread_t *t;
	zone_t *zone = curproc->p_zone;
	proc_t *pp = zone->zone_zsched;

	zone_hold(zone);	/* Reference to be dropped when thread exits */

	/*
	 * No-one should be trying to create threads if the zone is shutting
	 * down and there aren't any kernel threads around.  See comment
	 * in zthread_exit().
	 */
	ASSERT(!(zone->zone_kthreads == NULL &&
	    zone_status_get(zone) >= ZONE_IS_EMPTY));
	/*
	 * Create a thread, but don't let it run until we've finished setting
	 * things up.
	 */
	t = thread_create(stk, stksize, proc, arg, len, pp, TS_STOPPED, pri);
	ASSERT(t->t_forw == NULL);
	mutex_enter(&zone_status_lock);
	if (zone->zone_kthreads == NULL) {
		t->t_forw = t->t_back = t;
	} else {
		kthread_t *tx = zone->zone_kthreads;

		t->t_forw = tx;
		t->t_back = tx->t_back;
		tx->t_back->t_forw = t;
		tx->t_back = t;
	}
	zone->zone_kthreads = t;
	mutex_exit(&zone_status_lock);

	mutex_enter(&pp->p_lock);
	t->t_proc_flag |= TP_ZTHREAD;
	project_rele(t->t_proj);
	t->t_proj = project_hold(pp->p_task->tk_proj);

	/*
	 * Setup complete, let it run.
	 */
	thread_lock(t);
	t->t_schedflag |= TS_ALLSTART;
	setrun_locked(t);
	thread_unlock(t);

	mutex_exit(&pp->p_lock);

	return (t);
}

/*
 * Similar to thread_exit().  Must be called by threads created via
 * zthread_exit().
 */
void
zthread_exit(void)
{
	kthread_t *t = curthread;
	proc_t *pp = curproc;
	zone_t *zone = pp->p_zone;

	mutex_enter(&zone_status_lock);

	/*
	 * Reparent to p0
	 */
	mutex_enter(&pp->p_lock);
	t->t_proc_flag &= ~TP_ZTHREAD;
	t->t_procp = &p0;
	hat_thread_exit(t);
	mutex_exit(&pp->p_lock);

	if (t->t_back == t) {
		ASSERT(t->t_forw == t);
		/*
		 * If the zone is empty, once the thread count
		 * goes to zero no further kernel threads can be
		 * created.  This is because if the creator is a process
		 * in the zone, then it must have exited before the zone
		 * state could be set to ZONE_IS_EMPTY.
		 * Otherwise, if the creator is a kernel thread in the
		 * zone, the thread count is non-zero.
		 *
		 * This really means that non-zone kernel threads should
		 * not create zone kernel threads.
		 */
		zone->zone_kthreads = NULL;
		if (zone_status_get(zone) == ZONE_IS_EMPTY) {
			zone_status_set(zone, ZONE_IS_DOWN);
		}
	} else {
		t->t_forw->t_back = t->t_back;
		t->t_back->t_forw = t->t_forw;
		if (zone->zone_kthreads == t)
			zone->zone_kthreads = t->t_forw;
	}
	mutex_exit(&zone_status_lock);
	zone_rele(zone);
	thread_exit();
	/* NOTREACHED */
}

static void
zone_chdir(vnode_t *vp, vnode_t **vpp, proc_t *pp)
{
	vnode_t *oldvp;

	/* we're going to hold a reference here to the directory */
	VN_HOLD(vp);

#ifdef C2_AUDIT
	if (audit_active)	/* update abs cwd/root path see c2audit.c */
		audit_chdirec(vp, vpp);
#endif

	mutex_enter(&pp->p_lock);
	oldvp = *vpp;
	*vpp = vp;
	mutex_exit(&pp->p_lock);
	if (oldvp != NULL)
		VN_RELE(oldvp);
}

/*
 * Convert an rctl value represented by an nvlist_t into an rctl_val_t.
 */
static int
nvlist2rctlval(nvlist_t *nvl, rctl_val_t *rv)
{
	nvpair_t *nvp = NULL;
	boolean_t priv_set = B_FALSE;
	boolean_t limit_set = B_FALSE;
	boolean_t action_set = B_FALSE;

	while ((nvp = nvlist_next_nvpair(nvl, nvp)) != NULL) {
		const char *name;
		uint64_t ui64;

		name = nvpair_name(nvp);
		if (nvpair_type(nvp) != DATA_TYPE_UINT64)
			return (EINVAL);
		(void) nvpair_value_uint64(nvp, &ui64);
		if (strcmp(name, "privilege") == 0) {
			/*
			 * Currently only privileged values are allowed, but
			 * this may change in the future.
			 */
			if (ui64 != RCPRIV_PRIVILEGED)
				return (EINVAL);
			rv->rcv_privilege = ui64;
			priv_set = B_TRUE;
		} else if (strcmp(name, "limit") == 0) {
			rv->rcv_value = ui64;
			limit_set = B_TRUE;
		} else if (strcmp(name, "action") == 0) {
			if (ui64 != RCTL_LOCAL_NOACTION &&
			    ui64 != RCTL_LOCAL_DENY)
				return (EINVAL);
			rv->rcv_flagaction = ui64;
			action_set = B_TRUE;
		} else {
			return (EINVAL);
		}
	}

	if (!(priv_set && limit_set && action_set))
		return (EINVAL);
	rv->rcv_action_signal = 0;
	rv->rcv_action_recipient = NULL;
	rv->rcv_action_recip_pid = -1;
	rv->rcv_firing_time = 0;

	return (0);
}

void
zone_icode(void)
{
	proc_t *p = ttoproc(curthread);
	struct core_globals	*cg;

	/*
	 * For all purposes (ZONE_ATTR_INITPID and restart_init),
	 * storing just the pid of init is sufficient.
	 */
	p->p_zone->zone_proc_initpid = p->p_pid;

	/*
	 * Allocate user address space and stack segment
	 */

	p->p_cstime = p->p_stime = p->p_cutime = p->p_utime = 0;
	p->p_usrstack = (caddr_t)USRSTACK32;
	p->p_model = DATAMODEL_ILP32;
	p->p_stkprot = PROT_ZFOD & ~PROT_EXEC;
	p->p_datprot = PROT_ZFOD & ~PROT_EXEC;
	p->p_stk_ctl = INT32_MAX;

	p->p_as = as_alloc();
	p->p_as->a_userlimit = (caddr_t)USERLIMIT32;
	(void) hat_setup(p->p_as->a_hat, HAT_INIT);

	cg = zone_getspecific(core_zone_key, p->p_zone);
	ASSERT(cg != NULL);
	corectl_path_hold(cg->core_default_path);
	corectl_content_hold(cg->core_default_content);
	p->p_corefile = cg->core_default_path;
	p->p_content = cg->core_default_content;

	init_mstate(curthread, LMS_SYSTEM);

	p->p_zone->zone_boot_err = exec_init(zone_initname, 0,
	    p->p_zone->zone_bootargs);

	mutex_enter(&zone_status_lock);
	if (p->p_zone->zone_boot_err != 0) {
		/*
		 * Make sure we are still in the booting state-- we could have
		 * raced and already be shutting down, or even further along.
		 */
		if (zone_status_get(p->p_zone) == ZONE_IS_BOOTING)
			zone_status_set(p->p_zone, ZONE_IS_SHUTTING_DOWN);
		mutex_exit(&zone_status_lock);
		/* It's gone bad, dispose of the process */
		if (proc_exit(CLD_EXITED, p->p_zone->zone_boot_err) != 0) {
			mutex_enter(&p->p_lock);
			ASSERT(p->p_flag & SEXITLWPS);
			lwp_exit();
		}
	} else {
		if (zone_status_get(p->p_zone) == ZONE_IS_BOOTING)
			zone_status_set(p->p_zone, ZONE_IS_RUNNING);
		mutex_exit(&zone_status_lock);
		/* cause the process to return to userland. */
		lwp_rtt();
	}
}

struct zsched_arg {
	zone_t *zone;
	nvlist_t *nvlist;
};

/*
 * Per-zone "sched" workalike.  The similarity to "sched" doesn't have
 * anything to do with scheduling, but rather with the fact that
 * per-zone kernel threads are parented to zsched, just like regular
 * kernel threads are parented to sched (p0).
 *
 * zsched is also responsible for launching init for the zone.
 */
static void
zsched(void *arg)
{
	struct zsched_arg *za = arg;
	proc_t *pp = curproc;
	proc_t *initp = proc_init;
	zone_t *zone = za->zone;
	cred_t *cr, *oldcred;
	rctl_set_t *set;
	rctl_alloc_gp_t *gp;
	contract_t *ct = NULL;
	task_t *tk, *oldtk;
	rctl_entity_p_t e;
	kproject_t *pj;

	nvlist_t *nvl = za->nvlist;
	nvpair_t *nvp = NULL;

	bcopy("zsched", u.u_psargs, sizeof ("zsched"));
	bcopy("zsched", u.u_comm, sizeof ("zsched"));
	u.u_argc = 0;
	u.u_argv = NULL;
	u.u_envp = NULL;
	closeall(P_FINFO(pp));

	/*
	 * We are this zone's "zsched" process.  As the zone isn't generally
	 * visible yet we don't need to grab any locks before initializing its
	 * zone_proc pointer.
	 */
	zone_hold(zone);  /* this hold is released by zone_destroy() */
	zone->zone_zsched = pp;
	mutex_enter(&pp->p_lock);
	pp->p_zone = zone;
	mutex_exit(&pp->p_lock);

	/*
	 * Disassociate process from its 'parent'; parent ourselves to init
	 * (pid 1) and change other values as needed.
	 */
	sess_create();

	mutex_enter(&pidlock);
	proc_detach(pp);
	pp->p_ppid = 1;
	pp->p_flag |= SZONETOP;
	pp->p_ancpid = 1;
	pp->p_parent = initp;
	pp->p_psibling = NULL;
	if (initp->p_child)
		initp->p_child->p_psibling = pp;
	pp->p_sibling = initp->p_child;
	initp->p_child = pp;

	/* Decrement what newproc() incremented. */
	upcount_dec(crgetruid(CRED()), GLOBAL_ZONEID);
	/*
	 * Our credentials are about to become kcred-like, so we don't care
	 * about the caller's ruid.
	 */
	upcount_inc(crgetruid(kcred), zone->zone_id);
	mutex_exit(&pidlock);

	/*
	 * getting out of global zone, so decrement lwp counts
	 */
	pj = pp->p_task->tk_proj;
	mutex_enter(&global_zone->zone_nlwps_lock);
	pj->kpj_nlwps -= pp->p_lwpcnt;
	global_zone->zone_nlwps -= pp->p_lwpcnt;
	mutex_exit(&global_zone->zone_nlwps_lock);

	/*
	 * Create and join a new task in project '0' of this zone.
	 *
	 * We don't need to call holdlwps() since we know we're the only lwp in
	 * this process.
	 *
	 * task_join() returns with p_lock held.
	 */
	tk = task_create(0, zone);
	mutex_enter(&cpu_lock);
	oldtk = task_join(tk, 0);
	mutex_exit(&curproc->p_lock);
	mutex_exit(&cpu_lock);
	task_rele(oldtk);

	/*
	 * add lwp counts to zsched's zone, and increment project's task count
	 * due to the task created in the above tasksys_settaskid
	 */
	pj = pp->p_task->tk_proj;
	mutex_enter(&zone->zone_nlwps_lock);
	pj->kpj_nlwps += pp->p_lwpcnt;
	pj->kpj_ntasks += 1;
	zone->zone_nlwps += pp->p_lwpcnt;
	mutex_exit(&zone->zone_nlwps_lock);

	/*
	 * The process was created by a process in the global zone, hence the
	 * credentials are wrong.  We might as well have kcred-ish credentials.
	 */
	cr = zone->zone_kcred;
	crhold(cr);
	mutex_enter(&pp->p_crlock);
	oldcred = pp->p_cred;
	pp->p_cred = cr;
	mutex_exit(&pp->p_crlock);
	crfree(oldcred);

	/*
	 * Hold credentials again (for thread)
	 */
	crhold(cr);

	/*
	 * p_lwpcnt can't change since this is a kernel process.
	 */
	crset(pp, cr);

	/*
	 * Chroot
	 */
	zone_chdir(zone->zone_rootvp, &PTOU(pp)->u_cdir, pp);
	zone_chdir(zone->zone_rootvp, &PTOU(pp)->u_rdir, pp);

	/*
	 * Initialize zone's rctl set.
	 */
	set = rctl_set_create();
	gp = rctl_set_init_prealloc(RCENTITY_ZONE);
	mutex_enter(&pp->p_lock);
	e.rcep_p.zone = zone;
	e.rcep_t = RCENTITY_ZONE;
	zone->zone_rctls = rctl_set_init(RCENTITY_ZONE, pp, &e, set, gp);
	mutex_exit(&pp->p_lock);
	rctl_prealloc_destroy(gp);

	/*
	 * Apply the rctls passed in to zone_create().  This is basically a list
	 * assignment: all of the old values are removed and the new ones
	 * inserted.  That is, if an empty list is passed in, all values are
	 * removed.
	 */
	while ((nvp = nvlist_next_nvpair(nvl, nvp)) != NULL) {
		rctl_dict_entry_t *rde;
		rctl_hndl_t hndl;
		char *name;
		nvlist_t **nvlarray;
		uint_t i, nelem;
		int error;	/* For ASSERT()s */

		name = nvpair_name(nvp);
		hndl = rctl_hndl_lookup(name);
		ASSERT(hndl != -1);
		rde = rctl_dict_lookup_hndl(hndl);
		ASSERT(rde != NULL);

		for (; /* ever */; ) {
			rctl_val_t oval;

			mutex_enter(&pp->p_lock);
			error = rctl_local_get(hndl, NULL, &oval, pp);
			mutex_exit(&pp->p_lock);
			ASSERT(error == 0);	/* Can't fail for RCTL_FIRST */
			ASSERT(oval.rcv_privilege != RCPRIV_BASIC);
			if (oval.rcv_privilege == RCPRIV_SYSTEM)
				break;
			mutex_enter(&pp->p_lock);
			error = rctl_local_delete(hndl, &oval, pp);
			mutex_exit(&pp->p_lock);
			ASSERT(error == 0);
		}
		error = nvpair_value_nvlist_array(nvp, &nvlarray, &nelem);
		ASSERT(error == 0);
		for (i = 0; i < nelem; i++) {
			rctl_val_t *nvalp;

			nvalp = kmem_cache_alloc(rctl_val_cache, KM_SLEEP);
			error = nvlist2rctlval(nvlarray[i], nvalp);
			ASSERT(error == 0);
			/*
			 * rctl_local_insert can fail if the value being
			 * inserted is a duplicate; this is OK.
			 */
			mutex_enter(&pp->p_lock);
			if (rctl_local_insert(hndl, nvalp, pp) != 0)
				kmem_cache_free(rctl_val_cache, nvalp);
			mutex_exit(&pp->p_lock);
		}
	}
	/*
	 * Tell the world that we're done setting up.
	 *
	 * At this point we want to set the zone status to ZONE_IS_READY
	 * and atomically set the zone's processor set visibility.  Once
	 * we drop pool_lock() this zone will automatically get updated
	 * to reflect any future changes to the pools configuration.
	 */
	pool_lock();
	mutex_enter(&cpu_lock);
	mutex_enter(&zonehash_lock);
	zone_uniqid(zone);
	zone_zsd_configure(zone);
	if (pool_state == POOL_ENABLED)
		zone_pset_set(zone, pool_default->pool_pset->pset_id);
	mutex_enter(&zone_status_lock);
	ASSERT(zone_status_get(zone) == ZONE_IS_UNINITIALIZED);
	zone_status_set(zone, ZONE_IS_READY);
	mutex_exit(&zone_status_lock);
	mutex_exit(&zonehash_lock);
	mutex_exit(&cpu_lock);
	pool_unlock();

	/*
	 * Once we see the zone transition to the ZONE_IS_BOOTING state,
	 * we launch init, and set the state to running.
	 */
	zone_status_wait_cpr(zone, ZONE_IS_BOOTING, "zsched");

	if (zone_status_get(zone) == ZONE_IS_BOOTING) {
		id_t cid;

		/*
		 * Ok, this is a little complicated.  We need to grab the
		 * zone's pool's scheduling class ID; note that by now, we
		 * are already bound to a pool if we need to be (zoneadmd
		 * will have done that to us while we're in the READY
		 * state).  *But* the scheduling class for the zone's 'init'
		 * must be explicitly passed to newproc, which doesn't
		 * respect pool bindings.
		 *
		 * We hold the pool_lock across the call to newproc() to
		 * close the obvious race: the pool's scheduling class
		 * could change before we manage to create the LWP with
		 * classid 'cid'.
		 */
		pool_lock();
		cid = pool_get_class(zone->zone_pool);
		if (cid == -1)
			cid = defaultcid;

		/*
		 * If this fails, zone_boot will ultimately fail.  The
		 * state of the zone will be set to SHUTTING_DOWN-- userland
		 * will have to tear down the zone, and fail, or try again.
		 */
		if ((zone->zone_boot_err = newproc(zone_icode, NULL, cid,
		    minclsyspri - 1, &ct)) != 0) {
			mutex_enter(&zone_status_lock);
			zone_status_set(zone, ZONE_IS_SHUTTING_DOWN);
			mutex_exit(&zone_status_lock);
		}
		pool_unlock();
	}

	/*
	 * Wait for zone_destroy() to be called.  This is what we spend
	 * most of our life doing.
	 */
	zone_status_wait_cpr(zone, ZONE_IS_DYING, "zsched");

	if (ct)
		/*
		 * At this point the process contract should be empty.
		 * (Though if it isn't, it's not the end of the world.)
		 */
		VERIFY(contract_abandon(ct, curproc, B_TRUE) == 0);

	/*
	 * Allow kcred to be freed when all referring processes
	 * (including this one) go away.  We can't just do this in
	 * zone_free because we need to wait for the zone_cred_ref to
	 * drop to 0 before calling zone_free, and the existence of
	 * zone_kcred will prevent that.  Thus, we call crfree here to
	 * balance the crdup in zone_create.  The crhold calls earlier
	 * in zsched will be dropped when the thread and process exit.
	 */
	crfree(zone->zone_kcred);
	zone->zone_kcred = NULL;

	exit(CLD_EXITED, 0);
}

/*
 * Helper function to determine if there are any submounts of the
 * provided path.  Used to make sure the zone doesn't "inherit" any
 * mounts from before it is created.
 */
static uint_t
zone_mount_count(const char *rootpath)
{
	vfs_t *vfsp;
	uint_t count = 0;
	size_t rootpathlen = strlen(rootpath);

	/*
	 * Holding zonehash_lock prevents race conditions with
	 * vfs_list_add()/vfs_list_remove() since we serialize with
	 * zone_find_by_path().
	 */
	ASSERT(MUTEX_HELD(&zonehash_lock));
	/*
	 * The rootpath must end with a '/'
	 */
	ASSERT(rootpath[rootpathlen - 1] == '/');

	/*
	 * This intentionally does not count the rootpath itself if that
	 * happens to be a mount point.
	 */
	vfs_list_read_lock();
	vfsp = rootvfs;
	do {
		if (strncmp(rootpath, refstr_value(vfsp->vfs_mntpt),
		    rootpathlen) == 0)
			count++;
		vfsp = vfsp->vfs_next;
	} while (vfsp != rootvfs);
	vfs_list_unlock();
	return (count);
}

/*
 * Helper function to make sure that a zone created on 'rootpath'
 * wouldn't end up containing other zones' rootpaths.
 */
static boolean_t
zone_is_nested(const char *rootpath)
{
	zone_t *zone;
	size_t rootpathlen = strlen(rootpath);
	size_t len;

	ASSERT(MUTEX_HELD(&zonehash_lock));

	for (zone = list_head(&zone_active); zone != NULL;
	    zone = list_next(&zone_active, zone)) {
		if (zone == global_zone)
			continue;
		len = strlen(zone->zone_rootpath);
		if (strncmp(rootpath, zone->zone_rootpath,
		    MIN(rootpathlen, len)) == 0)
			return (B_TRUE);
	}
	return (B_FALSE);
}

static int
zone_set_privset(zone_t *zone, const priv_set_t *zone_privs,
    size_t zone_privssz)
{
	priv_set_t *privs = kmem_alloc(sizeof (priv_set_t), KM_SLEEP);

	if (zone_privssz < sizeof (priv_set_t))
		return (set_errno(ENOMEM));

	if (copyin(zone_privs, privs, sizeof (priv_set_t))) {
		kmem_free(privs, sizeof (priv_set_t));
		return (EFAULT);
	}

	zone->zone_privset = privs;
	return (0);
}

/*
 * We make creative use of nvlists to pass in rctls from userland.  The list is
 * a list of the following structures:
 *
 * (name = rctl_name, value = nvpair_list_array)
 *
 * Where each element of the nvpair_list_array is of the form:
 *
 * [(name = "privilege", value = RCPRIV_PRIVILEGED),
 * 	(name = "limit", value = uint64_t),
 * 	(name = "action", value = (RCTL_LOCAL_NOACTION || RCTL_LOCAL_DENY))]
 */
static int
parse_rctls(caddr_t ubuf, size_t buflen, nvlist_t **nvlp)
{
	nvpair_t *nvp = NULL;
	nvlist_t *nvl = NULL;
	char *kbuf;
	int error;
	rctl_val_t rv;

	*nvlp = NULL;

	if (buflen == 0)
		return (0);

	if ((kbuf = kmem_alloc(buflen, KM_NOSLEEP)) == NULL)
		return (ENOMEM);
	if (copyin(ubuf, kbuf, buflen)) {
		error = EFAULT;
		goto out;
	}
	if (nvlist_unpack(kbuf, buflen, &nvl, KM_SLEEP) != 0) {
		/*
		 * nvl may have been allocated/free'd, but the value set to
		 * non-NULL, so we reset it here.
		 */
		nvl = NULL;
		error = EINVAL;
		goto out;
	}
	while ((nvp = nvlist_next_nvpair(nvl, nvp)) != NULL) {
		rctl_dict_entry_t *rde;
		rctl_hndl_t hndl;
		nvlist_t **nvlarray;
		uint_t i, nelem;
		char *name;

		error = EINVAL;
		name = nvpair_name(nvp);
		if (strncmp(nvpair_name(nvp), "zone.", sizeof ("zone.") - 1)
		    != 0 || nvpair_type(nvp) != DATA_TYPE_NVLIST_ARRAY) {
			goto out;
		}
		if ((hndl = rctl_hndl_lookup(name)) == -1) {
			goto out;
		}
		rde = rctl_dict_lookup_hndl(hndl);
		error = nvpair_value_nvlist_array(nvp, &nvlarray, &nelem);
		ASSERT(error == 0);
		for (i = 0; i < nelem; i++) {
			if (error = nvlist2rctlval(nvlarray[i], &rv))
				goto out;
		}
		if (rctl_invalid_value(rde, &rv)) {
			error = EINVAL;
			goto out;
		}
	}
	error = 0;
	*nvlp = nvl;
out:
	kmem_free(kbuf, buflen);
	if (error && nvl != NULL)
		nvlist_free(nvl);
	return (error);
}

int
zone_create_error(int er_error, int er_ext, int *er_out) {
	if (er_out != NULL) {
		if (copyout(&er_ext, er_out, sizeof (int))) {
			return (set_errno(EFAULT));
		}
	}
	return (set_errno(er_error));
}

/*
 * Parses a comma-separated list of ZFS datasets into a per-zone dictionary.
 */
static int
parse_zfs(zone_t *zone, caddr_t ubuf, size_t buflen)
{
	char *kbuf;
	char *dataset, *next;
	zone_dataset_t *zd;
	size_t len;

	if (ubuf == NULL || buflen == 0)
		return (0);

	if ((kbuf = kmem_alloc(buflen, KM_NOSLEEP)) == NULL)
		return (ENOMEM);

	if (copyin(ubuf, kbuf, buflen) != 0) {
		kmem_free(kbuf, buflen);
		return (EFAULT);
	}

	dataset = next = kbuf;
	for (;;) {
		zd = kmem_alloc(sizeof (zone_dataset_t), KM_SLEEP);

		next = strchr(dataset, ',');

		if (next == NULL)
			len = strlen(dataset);
		else
			len = next - dataset;

		zd->zd_dataset = kmem_alloc(len + 1, KM_SLEEP);
		bcopy(dataset, zd->zd_dataset, len);
		zd->zd_dataset[len] = '\0';

		list_insert_head(&zone->zone_datasets, zd);

		if (next == NULL)
			break;

		dataset = next + 1;
	}

	kmem_free(kbuf, buflen);
	return (0);
}

/*
 * System call to create/initialize a new zone named 'zone_name', rooted
 * at 'zone_root', with a zone-wide privilege limit set of 'zone_privs',
 * and initialized with the zone-wide rctls described in 'rctlbuf'.
 *
 * If extended error is non-null, we may use it to return more detailed
 * error information.
 */
static zoneid_t
zone_create(const char *zone_name, const char *zone_root,
    const priv_set_t *zone_privs, size_t zone_privssz,
    caddr_t rctlbuf, size_t rctlbufsz,
    caddr_t zfsbuf, size_t zfsbufsz, int *extended_error)
{
	struct zsched_arg zarg;
	nvlist_t *rctls = NULL;
	proc_t *pp = curproc;
	zone_t *zone, *ztmp;
	zoneid_t zoneid;
	int error;
	int error2 = 0;
	char *str;
	cred_t *zkcr;

	if (secpolicy_zone_config(CRED()) != 0)
		return (set_errno(EPERM));

	/* can't boot zone from within chroot environment */
	if (PTOU(pp)->u_rdir != NULL && PTOU(pp)->u_rdir != rootdir)
		return (zone_create_error(ENOTSUP, ZE_CHROOTED,
		    extended_error));

	zone = kmem_zalloc(sizeof (zone_t), KM_SLEEP);
	zoneid = zone->zone_id = id_alloc(zoneid_space);
	zone->zone_status = ZONE_IS_UNINITIALIZED;
	zone->zone_pool = pool_default;
	zone->zone_pool_mod = gethrtime();
	zone->zone_psetid = ZONE_PS_INVAL;
	zone->zone_ncpus = 0;
	zone->zone_ncpus_online = 0;
	mutex_init(&zone->zone_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&zone->zone_nlwps_lock, NULL, MUTEX_DEFAULT, NULL);
	cv_init(&zone->zone_cv, NULL, CV_DEFAULT, NULL);
	list_create(&zone->zone_zsd, sizeof (struct zsd_entry),
	    offsetof(struct zsd_entry, zsd_linkage));
	list_create(&zone->zone_datasets, sizeof (zone_dataset_t),
	    offsetof(zone_dataset_t, zd_linkage));

	if ((error = zone_set_name(zone, zone_name)) != 0) {
		zone_free(zone);
		return (zone_create_error(error, 0, extended_error));
	}

	if ((error = zone_set_root(zone, zone_root)) != 0) {
		zone_free(zone);
		return (zone_create_error(error, 0, extended_error));
	}
	if ((error = zone_set_privset(zone, zone_privs, zone_privssz)) != 0) {
		zone_free(zone);
		return (zone_create_error(error, 0, extended_error));
	}

	/* initialize node name to be the same as zone name */
	zone->zone_nodename = kmem_alloc(_SYS_NMLN, KM_SLEEP);
	(void) strncpy(zone->zone_nodename, zone->zone_name, _SYS_NMLN);
	zone->zone_nodename[_SYS_NMLN - 1] = '\0';

	zone->zone_domain = kmem_alloc(_SYS_NMLN, KM_SLEEP);
	zone->zone_domain[0] = '\0';
	zone->zone_shares = 1;
	zone->zone_bootargs = NULL;

	/*
	 * Zsched initializes the rctls.
	 */
	zone->zone_rctls = NULL;

	if ((error = parse_rctls(rctlbuf, rctlbufsz, &rctls)) != 0) {
		zone_free(zone);
		return (zone_create_error(error, 0, extended_error));
	}

	if ((error = parse_zfs(zone, zfsbuf, zfsbufsz)) != 0) {
		zone_free(zone);
		return (set_errno(error));
	}

	/*
	 * Stop all lwps since that's what normally happens as part of fork().
	 * This needs to happen before we grab any locks to avoid deadlock
	 * (another lwp in the process could be waiting for the held lock).
	 */
	if (curthread != pp->p_agenttp && !holdlwps(SHOLDFORK)) {
		zone_free(zone);
		if (rctls)
			nvlist_free(rctls);
		return (zone_create_error(error, 0, extended_error));
	}

	if (block_mounts() == 0) {
		mutex_enter(&pp->p_lock);
		if (curthread != pp->p_agenttp)
			continuelwps(pp);
		mutex_exit(&pp->p_lock);
		zone_free(zone);
		if (rctls)
			nvlist_free(rctls);
		return (zone_create_error(error, 0, extended_error));
	}

	/*
	 * Set up credential for kernel access.  After this, any errors
	 * should go through the dance in errout rather than calling
	 * zone_free directly.
	 */
	zone->zone_kcred = crdup(kcred);
	crsetzone(zone->zone_kcred, zone);
	priv_intersect(zone->zone_privset, &CR_PPRIV(zone->zone_kcred));
	priv_intersect(zone->zone_privset, &CR_EPRIV(zone->zone_kcred));
	priv_intersect(zone->zone_privset, &CR_IPRIV(zone->zone_kcred));
	priv_intersect(zone->zone_privset, &CR_LPRIV(zone->zone_kcred));

	mutex_enter(&zonehash_lock);
	/*
	 * Make sure zone doesn't already exist.
	 */
	if ((ztmp = zone_find_all_by_name(zone->zone_name)) != NULL) {
		zone_status_t status;

		status = zone_status_get(ztmp);
		if (status == ZONE_IS_READY || status == ZONE_IS_RUNNING)
			error = EEXIST;
		else
			error = EBUSY;
		goto errout;
	}

	/*
	 * Don't allow zone creations which would cause one zone's rootpath to
	 * be accessible from that of another (non-global) zone.
	 */
	if (zone_is_nested(zone->zone_rootpath)) {
		error = EBUSY;
		goto errout;
	}

	ASSERT(zonecount != 0);		/* check for leaks */
	if (zonecount + 1 > maxzones) {
		error = ENOMEM;
		goto errout;
	}

	if (zone_mount_count(zone->zone_rootpath) != 0) {
		error = EBUSY;
		error2 = ZE_AREMOUNTS;
		goto errout;
	}

	/*
	 * Zone is still incomplete, but we need to drop all locks while
	 * zsched() initializes this zone's kernel process.  We
	 * optimistically add the zone to the hashtable and associated
	 * lists so a parallel zone_create() doesn't try to create the
	 * same zone.
	 */
	zonecount++;
	(void) mod_hash_insert(zonehashbyid,
	    (mod_hash_key_t)(uintptr_t)zone->zone_id,
	    (mod_hash_val_t)(uintptr_t)zone);
	str = kmem_alloc(strlen(zone->zone_name) + 1, KM_SLEEP);
	(void) strcpy(str, zone->zone_name);
	(void) mod_hash_insert(zonehashbyname, (mod_hash_key_t)str,
	    (mod_hash_val_t)(uintptr_t)zone);
	/*
	 * Insert into active list.  At this point there are no 'hold's
	 * on the zone, but everyone else knows not to use it, so we can
	 * continue to use it.  zsched() will do a zone_hold() if the
	 * newproc() is successful.
	 */
	list_insert_tail(&zone_active, zone);
	mutex_exit(&zonehash_lock);

	zarg.zone = zone;
	zarg.nvlist = rctls;
	/*
	 * The process, task, and project rctls are probably wrong;
	 * we need an interface to get the default values of all rctls,
	 * and initialize zsched appropriately.  I'm not sure that that
	 * makes much of a difference, though.
	 */
	if (error = newproc(zsched, (void *)&zarg, syscid, minclsyspri, NULL)) {
		/*
		 * We need to undo all globally visible state.
		 */
		mutex_enter(&zonehash_lock);
		list_remove(&zone_active, zone);
		(void) mod_hash_destroy(zonehashbyname,
		    (mod_hash_key_t)(uintptr_t)zone->zone_name);
		(void) mod_hash_destroy(zonehashbyid,
		    (mod_hash_key_t)(uintptr_t)zone->zone_id);
		ASSERT(zonecount > 1);
		zonecount--;
		goto errout;
	}

	/*
	 * Zone creation can't fail from now on.
	 */

	/*
	 * Let the other lwps continue.
	 */
	mutex_enter(&pp->p_lock);
	if (curthread != pp->p_agenttp)
		continuelwps(pp);
	mutex_exit(&pp->p_lock);

	/*
	 * Wait for zsched to finish initializing the zone.
	 */
	zone_status_wait(zone, ZONE_IS_READY);
	/*
	 * The zone is fully visible, so we can let mounts progress.
	 */
	resume_mounts();
	if (rctls)
		nvlist_free(rctls);

	return (zoneid);

errout:
	mutex_exit(&zonehash_lock);
	/*
	 * Let the other lwps continue.
	 */
	mutex_enter(&pp->p_lock);
	if (curthread != pp->p_agenttp)
		continuelwps(pp);
	mutex_exit(&pp->p_lock);

	resume_mounts();
	if (rctls)
		nvlist_free(rctls);
	/*
	 * There is currently one reference to the zone, a cred_ref from
	 * zone_kcred.  To free the zone, we call crfree, which will call
	 * zone_cred_rele, which will call zone_free.
	 */
	ASSERT(zone->zone_cred_ref == 1);	/* for zone_kcred */
	ASSERT(zone->zone_kcred->cr_ref == 1);
	ASSERT(zone->zone_ref == 0);
	zkcr = zone->zone_kcred;
	zone->zone_kcred = NULL;
	crfree(zkcr);				/* triggers call to zone_free */
	return (zone_create_error(error, error2, extended_error));
}

/*
 * Cause the zone to boot.  This is pretty simple, since we let zoneadmd do
 * the heavy lifting.
 */
static int
zone_boot(zoneid_t zoneid, const char *bootargs)
{
	int err;
	zone_t *zone;

	if (secpolicy_zone_config(CRED()) != 0)
		return (set_errno(EPERM));
	if (zoneid < MIN_USERZONEID || zoneid > MAX_ZONEID)
		return (set_errno(EINVAL));

	mutex_enter(&zonehash_lock);
	/*
	 * Look for zone under hash lock to prevent races with calls to
	 * zone_shutdown, zone_destroy, etc.
	 */
	if ((zone = zone_find_all_by_id(zoneid)) == NULL) {
		mutex_exit(&zonehash_lock);
		return (set_errno(EINVAL));
	}

	if ((err = zone_set_bootargs(zone, bootargs)) != 0) {
		mutex_exit(&zonehash_lock);
		return (set_errno(err));
	}

	mutex_enter(&zone_status_lock);
	if (zone_status_get(zone) != ZONE_IS_READY) {
		mutex_exit(&zone_status_lock);
		mutex_exit(&zonehash_lock);
		return (set_errno(EINVAL));
	}
	zone_status_set(zone, ZONE_IS_BOOTING);
	mutex_exit(&zone_status_lock);

	zone_hold(zone);	/* so we can use the zone_t later */
	mutex_exit(&zonehash_lock);

	if (zone_status_wait_sig(zone, ZONE_IS_RUNNING) == 0) {
		zone_rele(zone);
		return (set_errno(EINTR));
	}

	/*
	 * Boot (starting init) might have failed, in which case the zone
	 * will go to the SHUTTING_DOWN state; an appropriate errno will
	 * be placed in zone->zone_boot_err, and so we return that.
	 */
	err = zone->zone_boot_err;
	zone_rele(zone);
	return (err ? set_errno(err) : 0);
}

/*
 * Kills all user processes in the zone, waiting for them all to exit
 * before returning.
 */
static int
zone_empty(zone_t *zone)
{
	int waitstatus;

	/*
	 * We need to drop zonehash_lock before killing all
	 * processes, otherwise we'll deadlock with zone_find_*
	 * which can be called from the exit path.
	 */
	ASSERT(MUTEX_NOT_HELD(&zonehash_lock));
	while ((waitstatus = zone_status_timedwait_sig(zone, lbolt + hz,
	    ZONE_IS_EMPTY)) == -1) {
		killall(zone->zone_id);
	}
	/*
	 * return EINTR if we were signaled
	 */
	if (waitstatus == 0)
		return (EINTR);
	return (0);
}

/*
 * Systemcall to start the zone's halt sequence.  By the time this
 * function successfully returns, all user processes and kernel threads
 * executing in it will have exited, ZSD shutdown callbacks executed,
 * and the zone status set to ZONE_IS_DOWN.
 *
 * It is possible that the call will interrupt itself if the caller is the
 * parent of any process running in the zone, and doesn't have SIGCHLD blocked.
 */
static int
zone_shutdown(zoneid_t zoneid)
{
	int error;
	zone_t *zone;
	zone_status_t status;

	if (secpolicy_zone_config(CRED()) != 0)
		return (set_errno(EPERM));
	if (zoneid < MIN_USERZONEID || zoneid > MAX_ZONEID)
		return (set_errno(EINVAL));

	/*
	 * Block mounts so that VFS_MOUNT() can get an accurate view of
	 * the zone's status with regards to ZONE_IS_SHUTTING down.
	 *
	 * e.g. NFS can fail the mount if it determines that the zone
	 * has already begun the shutdown sequence.
	 */
	if (block_mounts() == 0)
		return (set_errno(EINTR));
	mutex_enter(&zonehash_lock);
	/*
	 * Look for zone under hash lock to prevent races with other
	 * calls to zone_shutdown and zone_destroy.
	 */
	if ((zone = zone_find_all_by_id(zoneid)) == NULL) {
		mutex_exit(&zonehash_lock);
		resume_mounts();
		return (set_errno(EINVAL));
	}
	mutex_enter(&zone_status_lock);
	status = zone_status_get(zone);
	/*
	 * Fail if the zone isn't fully initialized yet.
	 */
	if (status < ZONE_IS_READY) {
		mutex_exit(&zone_status_lock);
		mutex_exit(&zonehash_lock);
		resume_mounts();
		return (set_errno(EINVAL));
	}
	/*
	 * If conditions required for zone_shutdown() to return have been met,
	 * return success.
	 */
	if (status >= ZONE_IS_DOWN) {
		mutex_exit(&zone_status_lock);
		mutex_exit(&zonehash_lock);
		resume_mounts();
		return (0);
	}
	/*
	 * If zone_shutdown() hasn't been called before, go through the motions.
	 * If it has, there's nothing to do but wait for the kernel threads to
	 * drain.
	 */
	if (status < ZONE_IS_EMPTY) {
		uint_t ntasks;

		mutex_enter(&zone->zone_lock);
		if ((ntasks = zone->zone_ntasks) != 1) {
			/*
			 * There's still stuff running.
			 */
			zone_status_set(zone, ZONE_IS_SHUTTING_DOWN);
		}
		mutex_exit(&zone->zone_lock);
		if (ntasks == 1) {
			/*
			 * The only way to create another task is through
			 * zone_enter(), which will block until we drop
			 * zonehash_lock.  The zone is empty.
			 */
			if (zone->zone_kthreads == NULL) {
				/*
				 * Skip ahead to ZONE_IS_DOWN
				 */
				zone_status_set(zone, ZONE_IS_DOWN);
			} else {
				zone_status_set(zone, ZONE_IS_EMPTY);
			}
		}
	}
	zone_hold(zone);	/* so we can use the zone_t later */
	mutex_exit(&zone_status_lock);
	mutex_exit(&zonehash_lock);
	resume_mounts();

	if (error = zone_empty(zone)) {
		zone_rele(zone);
		return (set_errno(error));
	}
	/*
	 * After the zone status goes to ZONE_IS_DOWN this zone will no
	 * longer be notified of changes to the pools configuration, so
	 * in order to not end up with a stale pool pointer, we point
	 * ourselves at the default pool and remove all resource
	 * visibility.  This is especially important as the zone_t may
	 * languish on the deathrow for a very long time waiting for
	 * cred's to drain out.
	 *
	 * This rebinding of the zone can happen multiple times
	 * (presumably due to interrupted or parallel systemcalls)
	 * without any adverse effects.
	 */
	if (pool_lock_intr() != 0) {
		zone_rele(zone);
		return (set_errno(EINTR));
	}
	if (pool_state == POOL_ENABLED) {
		mutex_enter(&cpu_lock);
		zone_pool_set(zone, pool_default);
		/*
		 * The zone no longer needs to be able to see any cpus.
		 */
		zone_pset_set(zone, ZONE_PS_INVAL);
		mutex_exit(&cpu_lock);
	}
	pool_unlock();

	/*
	 * ZSD shutdown callbacks can be executed multiple times, hence
	 * it is safe to not be holding any locks across this call.
	 */
	zone_zsd_callbacks(zone, ZSD_SHUTDOWN);

	mutex_enter(&zone_status_lock);
	if (zone->zone_kthreads == NULL && zone_status_get(zone) < ZONE_IS_DOWN)
		zone_status_set(zone, ZONE_IS_DOWN);
	mutex_exit(&zone_status_lock);

	/*
	 * Wait for kernel threads to drain.
	 */
	if (!zone_status_wait_sig(zone, ZONE_IS_DOWN)) {
		zone_rele(zone);
		return (set_errno(EINTR));
	}
	zone_rele(zone);
	return (0);
}

/*
 * Systemcall entry point to finalize the zone halt process.  The caller
 * must have already successfully callefd zone_shutdown().
 *
 * Upon successful completion, the zone will have been fully destroyed:
 * zsched will have exited, destructor callbacks executed, and the zone
 * removed from the list of active zones.
 */
static int
zone_destroy(zoneid_t zoneid)
{
	uint64_t uniqid;
	zone_t *zone;
	zone_status_t status;

	if (secpolicy_zone_config(CRED()) != 0)
		return (set_errno(EPERM));
	if (zoneid < MIN_USERZONEID || zoneid > MAX_ZONEID)
		return (set_errno(EINVAL));

	mutex_enter(&zonehash_lock);
	/*
	 * Look for zone under hash lock to prevent races with other
	 * calls to zone_destroy.
	 */
	if ((zone = zone_find_all_by_id(zoneid)) == NULL) {
		mutex_exit(&zonehash_lock);
		return (set_errno(EINVAL));
	}

	if (zone_mount_count(zone->zone_rootpath) != 0) {
		mutex_exit(&zonehash_lock);
		return (set_errno(EBUSY));
	}
	mutex_enter(&zone_status_lock);
	status = zone_status_get(zone);
	if (status < ZONE_IS_DOWN) {
		mutex_exit(&zone_status_lock);
		mutex_exit(&zonehash_lock);
		return (set_errno(EBUSY));
	} else if (status == ZONE_IS_DOWN) {
		zone_status_set(zone, ZONE_IS_DYING); /* Tell zsched to exit */
	}
	mutex_exit(&zone_status_lock);
	zone_hold(zone);
	mutex_exit(&zonehash_lock);

	/*
	 * wait for zsched to exit
	 */
	zone_status_wait(zone, ZONE_IS_DEAD);
	zone_zsd_callbacks(zone, ZSD_DESTROY);
	uniqid = zone->zone_uniqid;
	zone_rele(zone);
	zone = NULL;	/* potentially free'd */

	mutex_enter(&zonehash_lock);
	for (; /* ever */; ) {
		boolean_t unref;

		if ((zone = zone_find_all_by_id(zoneid)) == NULL ||
		    zone->zone_uniqid != uniqid) {
			/*
			 * The zone has gone away.  Necessary conditions
			 * are met, so we return success.
			 */
			mutex_exit(&zonehash_lock);
			return (0);
		}
		mutex_enter(&zone->zone_lock);
		unref = ZONE_IS_UNREF(zone);
		mutex_exit(&zone->zone_lock);
		if (unref) {
			/*
			 * There is only one reference to the zone -- that
			 * added when the zone was added to the hashtables --
			 * and things will remain this way until we drop
			 * zonehash_lock... we can go ahead and cleanup the
			 * zone.
			 */
			break;
		}

		if (cv_wait_sig(&zone_destroy_cv, &zonehash_lock) == 0) {
			/* Signaled */
			mutex_exit(&zonehash_lock);
			return (set_errno(EINTR));
		}

	}

	/*
	 * It is now safe to let the zone be recreated; remove it from the
	 * lists.  The memory will not be freed until the last cred
	 * reference goes away.
	 */
	ASSERT(zonecount > 1);	/* must be > 1; can't destroy global zone */
	zonecount--;
	/* remove from active list and hash tables */
	list_remove(&zone_active, zone);
	(void) mod_hash_destroy(zonehashbyname,
	    (mod_hash_key_t)zone->zone_name);
	(void) mod_hash_destroy(zonehashbyid,
	    (mod_hash_key_t)(uintptr_t)zone->zone_id);
	mutex_exit(&zonehash_lock);

	/*
	 * Release the root vnode; we're not using it anymore.  Nor should any
	 * other thread that might access it exist.
	 */
	if (zone->zone_rootvp != NULL) {
		VN_RELE(zone->zone_rootvp);
		zone->zone_rootvp = NULL;
	}

	/* add to deathrow list */
	mutex_enter(&zone_deathrow_lock);
	list_insert_tail(&zone_deathrow, zone);
	mutex_exit(&zone_deathrow_lock);

	/*
	 * Drop last reference (which was added by zsched()), this will
	 * free the zone unless there are outstanding cred references.
	 */
	zone_rele(zone);
	return (0);
}

/*
 * Systemcall entry point for zone_getattr(2).
 */
static ssize_t
zone_getattr(zoneid_t zoneid, int attr, void *buf, size_t bufsize)
{
	size_t size;
	int error = 0, err;
	zone_t *zone;
	char *zonepath;
	zone_status_t zone_status;
	pid_t initpid;
	boolean_t global = (curproc->p_zone == global_zone);

	mutex_enter(&zonehash_lock);
	if ((zone = zone_find_all_by_id(zoneid)) == NULL) {
		mutex_exit(&zonehash_lock);
		return (set_errno(EINVAL));
	}
	zone_status = zone_status_get(zone);
	if (zone_status < ZONE_IS_READY) {
		mutex_exit(&zonehash_lock);
		return (set_errno(EINVAL));
	}
	zone_hold(zone);
	mutex_exit(&zonehash_lock);

	/*
	 * If not in the global zone, don't show information about other zones.
	 */
	if (!global && curproc->p_zone != zone) {
		zone_rele(zone);
		return (set_errno(EINVAL));
	}

	switch (attr) {
	case ZONE_ATTR_ROOT:
		if (global) {
			/*
			 * Copy the path to trim the trailing "/" (except for
			 * the global zone).
			 */
			if (zone != global_zone)
				size = zone->zone_rootpathlen - 1;
			else
				size = zone->zone_rootpathlen;
			zonepath = kmem_alloc(size, KM_SLEEP);
			bcopy(zone->zone_rootpath, zonepath, size);
			zonepath[size - 1] = '\0';
		} else {
			/*
			 * Caller is not in the global zone, just return
			 * faked-up path for current zone.
			 */
			zonepath = "/";
			size = 2;
		}
		if (bufsize > size)
			bufsize = size;
		if (buf != NULL) {
			err = copyoutstr(zonepath, buf, bufsize, NULL);
			if (err != 0 && err != ENAMETOOLONG)
				error = EFAULT;
		}
		if (global)
			kmem_free(zonepath, size);
		break;

	case ZONE_ATTR_NAME:
		size = strlen(zone->zone_name) + 1;
		if (bufsize > size)
			bufsize = size;
		if (buf != NULL) {
			err = copyoutstr(zone->zone_name, buf, bufsize, NULL);
			if (err != 0 && err != ENAMETOOLONG)
				error = EFAULT;
		}
		break;

	case ZONE_ATTR_STATUS:
		/*
		 * Since we're not holding zonehash_lock, the zone status
		 * may be anything; leave it up to userland to sort it out.
		 */
		size = sizeof (zone_status);
		if (bufsize > size)
			bufsize = size;
		zone_status = zone_status_get(zone);
		if (buf != NULL &&
		    copyout(&zone_status, buf, bufsize) != 0)
			error = EFAULT;
		break;
	case ZONE_ATTR_PRIVSET:
		size = sizeof (priv_set_t);
		if (bufsize > size)
			bufsize = size;
		if (buf != NULL &&
		    copyout(zone->zone_privset, buf, bufsize) != 0)
			error = EFAULT;
		break;
	case ZONE_ATTR_UNIQID:
		size = sizeof (zone->zone_uniqid);
		if (bufsize > size)
			bufsize = size;
		if (buf != NULL &&
		    copyout(&zone->zone_uniqid, buf, bufsize) != 0)
			error = EFAULT;
		break;
	case ZONE_ATTR_POOLID:
		{
			pool_t *pool;
			poolid_t poolid;

			if (pool_lock_intr() != 0) {
				error = EINTR;
				break;
			}
			pool = zone_pool_get(zone);
			poolid = pool->pool_id;
			pool_unlock();
			size = sizeof (poolid);
			if (bufsize > size)
				bufsize = size;
			if (buf != NULL && copyout(&poolid, buf, size) != 0)
				error = EFAULT;
		}
		break;
	case ZONE_ATTR_INITPID:
		size = sizeof (initpid);
		if (bufsize > size)
			bufsize = size;
		initpid = zone->zone_proc_initpid;
		if (initpid == -1) {
			error = ESRCH;
			break;
		}
		if (buf != NULL &&
		    copyout(&initpid, buf, bufsize) != 0)
			error = EFAULT;
		break;
	default:
		error = EINVAL;
	}
	zone_rele(zone);

	if (error)
		return (set_errno(error));
	return ((ssize_t)size);
}

/*
 * Return zero if the process has at least one vnode mapped in to its
 * address space which shouldn't be allowed to change zones.
 */
static int
as_can_change_zones(void)
{
	proc_t *pp = curproc;
	struct seg *seg;
	struct as *as = pp->p_as;
	vnode_t *vp;
	int allow = 1;

	ASSERT(pp->p_as != &kas);
	AS_LOCK_ENTER(&as, &as->a_lock, RW_READER);
	for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
		/*
		 * if we can't get a backing vnode for this segment then skip
		 * it.
		 */
		vp = NULL;
		if (SEGOP_GETVP(seg, seg->s_base, &vp) != 0 || vp == NULL)
			continue;
		if (!vn_can_change_zones(vp)) { /* bail on first match */
			allow = 0;
			break;
		}
	}
	AS_LOCK_EXIT(&as, &as->a_lock);
	return (allow);
}

/*
 * Systemcall entry point for zone_enter().
 *
 * The current process is injected into said zone.  In the process
 * it will change its project membership, privileges, rootdir/cwd,
 * zone-wide rctls, and pool association to match those of the zone.
 *
 * The first zone_enter() called while the zone is in the ZONE_IS_READY
 * state will transition it to ZONE_IS_RUNNING.  Processes may only
 * enter a zone that is "ready" or "running".
 */
static int
zone_enter(zoneid_t zoneid)
{
	zone_t *zone;
	vnode_t *vp;
	proc_t *pp = curproc;
	contract_t *ct;
	cont_process_t *ctp;
	task_t *tk, *oldtk;
	kproject_t *zone_proj0;
	cred_t *cr, *newcr;
	pool_t *oldpool, *newpool;
	sess_t *sp;
	uid_t uid;
	zone_status_t status;
	int err = 0;
	rctl_entity_p_t e;

	if (secpolicy_zone_config(CRED()) != 0)
		return (set_errno(EPERM));
	if (zoneid < MIN_USERZONEID || zoneid > MAX_ZONEID)
		return (set_errno(EINVAL));

	/*
	 * Stop all lwps so we don't need to hold a lock to look at
	 * curproc->p_zone.  This needs to happen before we grab any
	 * locks to avoid deadlock (another lwp in the process could
	 * be waiting for the held lock).
	 */
	if (curthread != pp->p_agenttp && !holdlwps(SHOLDFORK))
		return (set_errno(EINTR));

	/*
	 * Make sure we're not changing zones with files open or mapped in
	 * to our address space which shouldn't be changing zones.
	 */
	if (!files_can_change_zones()) {
		err = EBADF;
		goto out;
	}
	if (!as_can_change_zones()) {
		err = EFAULT;
		goto out;
	}

	mutex_enter(&zonehash_lock);
	if (pp->p_zone != global_zone) {
		mutex_exit(&zonehash_lock);
		err = EINVAL;
		goto out;
	}

	zone = zone_find_all_by_id(zoneid);
	if (zone == NULL) {
		mutex_exit(&zonehash_lock);
		err = EINVAL;
		goto out;
	}

	/*
	 * To prevent processes in a zone from holding contracts on
	 * extrazonal resources, and to avoid process contract
	 * memberships which span zones, contract holders and processes
	 * which aren't the sole members of their encapsulating process
	 * contracts are not allowed to zone_enter.
	 */
	ctp = pp->p_ct_process;
	ct = &ctp->conp_contract;
	mutex_enter(&ct->ct_lock);
	mutex_enter(&pp->p_lock);
	if ((avl_numnodes(&pp->p_ct_held) != 0) || (ctp->conp_nmembers != 1)) {
		mutex_exit(&pp->p_lock);
		mutex_exit(&ct->ct_lock);
		mutex_exit(&zonehash_lock);
		pool_unlock();
		err = EINVAL;
		goto out;
	}

	/*
	 * Moreover, we don't allow processes whose encapsulating
	 * process contracts have inherited extrazonal contracts.
	 * While it would be easier to eliminate all process contracts
	 * with inherited contracts, we need to be able to give a
	 * restarted init (or other zone-penetrating process) its
	 * predecessor's contracts.
	 */
	if (ctp->conp_ninherited != 0) {
		contract_t *next;
		for (next = list_head(&ctp->conp_inherited); next;
		    next = list_next(&ctp->conp_inherited, next)) {
			if (contract_getzuniqid(next) != zone->zone_uniqid) {
				mutex_exit(&pp->p_lock);
				mutex_exit(&ct->ct_lock);
				mutex_exit(&zonehash_lock);
				pool_unlock();
				err = EINVAL;
				goto out;
			}
		}
	}
	mutex_exit(&pp->p_lock);
	mutex_exit(&ct->ct_lock);

	status = zone_status_get(zone);
	if (status < ZONE_IS_READY || status >= ZONE_IS_SHUTTING_DOWN) {
		/*
		 * Can't join
		 */
		mutex_exit(&zonehash_lock);
		err = EINVAL;
		goto out;
	}

	/*
	 * Make sure new priv set is within the permitted set for caller
	 */
	if (!priv_issubset(zone->zone_privset, &CR_OPPRIV(CRED()))) {
		mutex_exit(&zonehash_lock);
		err = EPERM;
		goto out;
	}
	/*
	 * We want to momentarily drop zonehash_lock while we optimistically
	 * bind curproc to the pool it should be running in.  This is safe
	 * since the zone can't disappear (we have a hold on it).
	 */
	zone_hold(zone);
	mutex_exit(&zonehash_lock);

	/*
	 * Grab pool_lock to keep the pools configuration from changing
	 * and to stop ourselves from getting rebound to another pool
	 * until we join the zone.
	 */
	if (pool_lock_intr() != 0) {
		zone_rele(zone);
		err = EINTR;
		goto out;
	}
	ASSERT(secpolicy_pool(CRED()) == 0);
	/*
	 * Bind ourselves to the pool currently associated with the zone.
	 */
	oldpool = curproc->p_pool;
	newpool = zone_pool_get(zone);
	if (pool_state == POOL_ENABLED && newpool != oldpool &&
	    (err = pool_do_bind(newpool, P_PID, P_MYID,
	    POOL_BIND_ALL)) != 0) {
		pool_unlock();
		zone_rele(zone);
		goto out;
	}

	/*
	 * Grab cpu_lock now; we'll need it later when we call
	 * task_join().
	 */
	mutex_enter(&cpu_lock);
	mutex_enter(&zonehash_lock);
	/*
	 * Make sure the zone hasn't moved on since we dropped zonehash_lock.
	 */
	if (zone_status_get(zone) >= ZONE_IS_SHUTTING_DOWN) {
		/*
		 * Can't join anymore.
		 */
		mutex_exit(&zonehash_lock);
		mutex_exit(&cpu_lock);
		if (pool_state == POOL_ENABLED &&
		    newpool != oldpool)
			(void) pool_do_bind(oldpool, P_PID, P_MYID,
			    POOL_BIND_ALL);
		pool_unlock();
		zone_rele(zone);
		err = EINVAL;
		goto out;
	}

	mutex_enter(&pp->p_lock);
	zone_proj0 = zone->zone_zsched->p_task->tk_proj;
	/* verify that we do not exceed and task or lwp limits */
	mutex_enter(&zone->zone_nlwps_lock);
	/* add new lwps to zone and zone's proj0 */
	zone_proj0->kpj_nlwps += pp->p_lwpcnt;
	zone->zone_nlwps += pp->p_lwpcnt;
	/* add 1 task to zone's proj0 */
	zone_proj0->kpj_ntasks += 1;
	mutex_exit(&pp->p_lock);
	mutex_exit(&zone->zone_nlwps_lock);

	/* remove lwps from proc's old zone and old project */
	mutex_enter(&pp->p_zone->zone_nlwps_lock);
	pp->p_zone->zone_nlwps -= pp->p_lwpcnt;
	pp->p_task->tk_proj->kpj_nlwps -= pp->p_lwpcnt;
	mutex_exit(&pp->p_zone->zone_nlwps_lock);

	/*
	 * Joining the zone cannot fail from now on.
	 *
	 * This means that a lot of the following code can be commonized and
	 * shared with zsched().
	 */

	/*
	 * Reset the encapsulating process contract's zone.
	 */
	ASSERT(ct->ct_mzuniqid == GLOBAL_ZONEUNIQID);
	contract_setzuniqid(ct, zone->zone_uniqid);

	/*
	 * Create a new task and associate the process with the project keyed
	 * by (projid,zoneid).
	 *
	 * We might as well be in project 0; the global zone's projid doesn't
	 * make much sense in a zone anyhow.
	 *
	 * This also increments zone_ntasks, and returns with p_lock held.
	 */
	tk = task_create(0, zone);
	oldtk = task_join(tk, 0);
	mutex_exit(&cpu_lock);

	pp->p_flag |= SZONETOP;
	pp->p_zone = zone;

	/*
	 * call RCTLOP_SET functions on this proc
	 */
	e.rcep_p.zone = zone;
	e.rcep_t = RCENTITY_ZONE;
	(void) rctl_set_dup(NULL, NULL, pp, &e, zone->zone_rctls, NULL,
	    RCD_CALLBACK);
	mutex_exit(&pp->p_lock);

	/*
	 * We don't need to hold any of zsched's locks here; not only do we know
	 * the process and zone aren't going away, we know its session isn't
	 * changing either.
	 *
	 * By joining zsched's session here, we mimic the behavior in the
	 * global zone of init's sid being the pid of sched.  We extend this
	 * to all zlogin-like zone_enter()'ing processes as well.
	 */
	mutex_enter(&pidlock);
	sp = zone->zone_zsched->p_sessp;
	SESS_HOLD(sp);
	mutex_enter(&pp->p_lock);
	pgexit(pp);
	SESS_RELE(pp->p_sessp);
	pp->p_sessp = sp;
	pgjoin(pp, zone->zone_zsched->p_pidp);
	mutex_exit(&pp->p_lock);
	mutex_exit(&pidlock);

	mutex_exit(&zonehash_lock);
	/*
	 * We're firmly in the zone; let pools progress.
	 */
	pool_unlock();
	task_rele(oldtk);
	/*
	 * We don't need to retain a hold on the zone since we already
	 * incremented zone_ntasks, so the zone isn't going anywhere.
	 */
	zone_rele(zone);

	/*
	 * Chroot
	 */
	vp = zone->zone_rootvp;
	zone_chdir(vp, &PTOU(pp)->u_cdir, pp);
	zone_chdir(vp, &PTOU(pp)->u_rdir, pp);

	/*
	 * Change process credentials
	 */
	newcr = cralloc();
	mutex_enter(&pp->p_crlock);
	cr = pp->p_cred;
	crcopy_to(cr, newcr);
	crsetzone(newcr, zone);
	pp->p_cred = newcr;

	/*
	 * Restrict all process privilege sets to zone limit
	 */
	priv_intersect(zone->zone_privset, &CR_PPRIV(newcr));
	priv_intersect(zone->zone_privset, &CR_EPRIV(newcr));
	priv_intersect(zone->zone_privset, &CR_IPRIV(newcr));
	priv_intersect(zone->zone_privset, &CR_LPRIV(newcr));
	mutex_exit(&pp->p_crlock);
	crset(pp, newcr);

	/*
	 * Adjust upcount to reflect zone entry.
	 */
	uid = crgetruid(newcr);
	mutex_enter(&pidlock);
	upcount_dec(uid, GLOBAL_ZONEID);
	upcount_inc(uid, zoneid);
	mutex_exit(&pidlock);

	/*
	 * Set up core file path and content.
	 */
	set_core_defaults();

out:
	/*
	 * Let the other lwps continue.
	 */
	mutex_enter(&pp->p_lock);
	if (curthread != pp->p_agenttp)
		continuelwps(pp);
	mutex_exit(&pp->p_lock);

	return (err != 0 ? set_errno(err) : 0);
}

/*
 * Systemcall entry point for zone_list(2).
 *
 * Processes running in a (non-global) zone only see themselves.
 */
static int
zone_list(zoneid_t *zoneidlist, uint_t *numzones)
{
	zoneid_t *zoneids;
	zone_t *zone;
	uint_t user_nzones, real_nzones;
	int error = 0;
	uint_t i;

	if (copyin(numzones, &user_nzones, sizeof (uint_t)) != 0)
		return (set_errno(EFAULT));

	if (curproc->p_zone != global_zone) {
		/* just return current zone */
		real_nzones = 1;
		zoneids = kmem_alloc(sizeof (zoneid_t), KM_SLEEP);
		zoneids[0] = curproc->p_zone->zone_id;
	} else {
		mutex_enter(&zonehash_lock);
		real_nzones = zonecount;
		if (real_nzones) {
			zoneids = kmem_alloc(real_nzones * sizeof (zoneid_t),
			    KM_SLEEP);
			i = 0;
			for (zone = list_head(&zone_active); zone != NULL;
			    zone = list_next(&zone_active, zone))
				zoneids[i++] = zone->zone_id;
			ASSERT(i == real_nzones);
		}
		mutex_exit(&zonehash_lock);
	}

	if (user_nzones > real_nzones)
		user_nzones = real_nzones;

	if (copyout(&real_nzones, numzones, sizeof (uint_t)) != 0)
		error = EFAULT;
	else if (zoneidlist != NULL && user_nzones != 0) {
		if (copyout(zoneids, zoneidlist,
		    user_nzones * sizeof (zoneid_t)) != 0)
			error = EFAULT;
	}

	if (real_nzones)
		kmem_free(zoneids, real_nzones * sizeof (zoneid_t));

	if (error)
		return (set_errno(error));
	else
		return (0);
}

/*
 * Systemcall entry point for zone_lookup(2).
 *
 * Non-global zones are only able to see themselves.
 */
static zoneid_t
zone_lookup(const char *zone_name)
{
	char *kname;
	zone_t *zone;
	zoneid_t zoneid;
	int err;

	if (zone_name == NULL) {
		/* return caller's zone id */
		return (getzoneid());
	}

	kname = kmem_zalloc(ZONENAME_MAX, KM_SLEEP);
	if ((err = copyinstr(zone_name, kname, ZONENAME_MAX, NULL)) != 0) {
		kmem_free(kname, ZONENAME_MAX);
		return (set_errno(err));
	}

	mutex_enter(&zonehash_lock);
	zone = zone_find_all_by_name(kname);
	kmem_free(kname, ZONENAME_MAX);
	if (zone == NULL || zone_status_get(zone) < ZONE_IS_READY ||
	    (curproc->p_zone != global_zone && curproc->p_zone != zone)) {
		/* in non-global zone, can only lookup own name */
		mutex_exit(&zonehash_lock);
		return (set_errno(EINVAL));
	}
	zoneid = zone->zone_id;
	mutex_exit(&zonehash_lock);
	return (zoneid);
}

static int
zone_version(int *version_arg)
{
	int version = ZONE_SYSCALL_API_VERSION;

	if (copyout(&version, version_arg, sizeof (int)) != 0)
		return (set_errno(EFAULT));
	return (0);
}

/* ARGSUSED */
long
zone(int cmd, void *arg1, void *arg2, void *arg3, void *arg4)
{
	zone_def zs;

	switch (cmd) {
	case ZONE_CREATE:
		if (get_udatamodel() == DATAMODEL_NATIVE) {
			if (copyin(arg1, &zs, sizeof (zone_def))) {
				return (set_errno(EFAULT));
			}
		} else {
#ifdef _SYSCALL32_IMPL
			zone_def32 zs32;

			if (copyin(arg1, &zs32, sizeof (zone_def32))) {
				return (set_errno(EFAULT));
			}
			zs.zone_name =
			    (const char *)(unsigned long)zs32.zone_name;
			zs.zone_root =
			    (const char *)(unsigned long)zs32.zone_root;
			zs.zone_privs =
			    (const struct priv_set *)
			    (unsigned long)zs32.zone_privs;
			zs.rctlbuf = (caddr_t)(unsigned long)zs32.rctlbuf;
			zs.rctlbufsz = zs32.rctlbufsz;
			zs.zfsbuf = (caddr_t)(unsigned long)zs32.zfsbuf;
			zs.zfsbufsz = zs32.zfsbufsz;
			zs.extended_error =
			    (int *)(unsigned long)zs32.extended_error;
#else
			panic("get_udatamodel() returned bogus result\n");
#endif
		}

		return (zone_create(zs.zone_name, zs.zone_root,
		    zs.zone_privs, zs.zone_privssz,
		    (caddr_t)zs.rctlbuf, zs.rctlbufsz,
		    (caddr_t)zs.zfsbuf, zs.zfsbufsz,
		    zs.extended_error));
	case ZONE_BOOT:
		return (zone_boot((zoneid_t)(uintptr_t)arg1,
		    (const char *)arg2));
	case ZONE_DESTROY:
		return (zone_destroy((zoneid_t)(uintptr_t)arg1));
	case ZONE_GETATTR:
		return (zone_getattr((zoneid_t)(uintptr_t)arg1,
		    (int)(uintptr_t)arg2, arg3, (size_t)arg4));
	case ZONE_ENTER:
		return (zone_enter((zoneid_t)(uintptr_t)arg1));
	case ZONE_LIST:
		return (zone_list((zoneid_t *)arg1, (uint_t *)arg2));
	case ZONE_SHUTDOWN:
		return (zone_shutdown((zoneid_t)(uintptr_t)arg1));
	case ZONE_LOOKUP:
		return (zone_lookup((const char *)arg1));
	case ZONE_VERSION:
		return (zone_version((int *)arg1));
	default:
		return (set_errno(EINVAL));
	}
}

struct zarg {
	zone_t *zone;
	zone_cmd_arg_t arg;
};

static int
zone_lookup_door(const char *zone_name, door_handle_t *doorp)
{
	char *buf;
	size_t buflen;
	int error;

	buflen = sizeof (ZONE_DOOR_PATH) + strlen(zone_name);
	buf = kmem_alloc(buflen, KM_SLEEP);
	(void) snprintf(buf, buflen, ZONE_DOOR_PATH, zone_name);
	error = door_ki_open(buf, doorp);
	kmem_free(buf, buflen);
	return (error);
}

static void
zone_release_door(door_handle_t *doorp)
{
	door_ki_rele(*doorp);
	*doorp = NULL;
}

static void
zone_ki_call_zoneadmd(struct zarg *zargp)
{
	door_handle_t door = NULL;
	door_arg_t darg, save_arg;
	char *zone_name;
	size_t zone_namelen;
	zoneid_t zoneid;
	zone_t *zone;
	zone_cmd_arg_t arg;
	uint64_t uniqid;
	size_t size;
	int error;
	int retry;

	zone = zargp->zone;
	arg = zargp->arg;
	kmem_free(zargp, sizeof (*zargp));

	zone_namelen = strlen(zone->zone_name) + 1;
	zone_name = kmem_alloc(zone_namelen, KM_SLEEP);
	bcopy(zone->zone_name, zone_name, zone_namelen);
	zoneid = zone->zone_id;
	uniqid = zone->zone_uniqid;
	/*
	 * zoneadmd may be down, but at least we can empty out the zone.
	 * We can ignore the return value of zone_empty() since we're called
	 * from a kernel thread and know we won't be delivered any signals.
	 */
	ASSERT(curproc == &p0);
	(void) zone_empty(zone);
	ASSERT(zone_status_get(zone) >= ZONE_IS_EMPTY);
	zone_rele(zone);

	size = sizeof (arg);
	darg.rbuf = (char *)&arg;
	darg.data_ptr = (char *)&arg;
	darg.rsize = size;
	darg.data_size = size;
	darg.desc_ptr = NULL;
	darg.desc_num = 0;

	save_arg = darg;
	/*
	 * Since we're not holding a reference to the zone, any number of
	 * things can go wrong, including the zone disappearing before we get a
	 * chance to talk to zoneadmd.
	 */
	for (retry = 0; /* forever */; retry++) {
		if (door == NULL &&
		    (error = zone_lookup_door(zone_name, &door)) != 0) {
			goto next;
		}
		ASSERT(door != NULL);

		if ((error = door_ki_upcall(door, &darg)) == 0) {
			break;
		}
		switch (error) {
		case EINTR:
			/* FALLTHROUGH */
		case EAGAIN:	/* process may be forking */
			/*
			 * Back off for a bit
			 */
			break;
		case EBADF:
			zone_release_door(&door);
			if (zone_lookup_door(zone_name, &door) != 0) {
				/*
				 * zoneadmd may be dead, but it may come back to
				 * life later.
				 */
				break;
			}
			break;
		default:
			cmn_err(CE_WARN,
			    "zone_ki_call_zoneadmd: door_ki_upcall error %d\n",
			    error);
			goto out;
		}
next:
		/*
		 * If this isn't the same zone_t that we originally had in mind,
		 * then this is the same as if two kadmin requests come in at
		 * the same time: the first one wins.  This means we lose, so we
		 * bail.
		 */
		if ((zone = zone_find_by_id(zoneid)) == NULL) {
			/*
			 * Problem is solved.
			 */
			break;
		}
		if (zone->zone_uniqid != uniqid) {
			/*
			 * zoneid recycled
			 */
			zone_rele(zone);
			break;
		}
		/*
		 * We could zone_status_timedwait(), but there doesn't seem to
		 * be much point in doing that (plus, it would mean that
		 * zone_free() isn't called until this thread exits).
		 */
		zone_rele(zone);
		delay(hz);
		darg = save_arg;
	}
out:
	if (door != NULL) {
		zone_release_door(&door);
	}
	kmem_free(zone_name, zone_namelen);
	thread_exit();
}

/*
 * Entry point for uadmin() to tell the zone to go away or reboot.  The caller
 * is a process in the zone to be modified.
 *
 * In order to shutdown the zone, we will hand off control to zoneadmd
 * (running in the global zone) via a door.  We do a half-hearted job at
 * killing all processes in the zone, create a kernel thread to contact
 * zoneadmd, and make note of the "uniqid" of the zone.  The uniqid is
 * a form of generation number used to let zoneadmd (as well as
 * zone_destroy()) know exactly which zone they're re talking about.
 */
int
zone_uadmin(int cmd, int fcn, cred_t *credp)
{
	struct zarg *zargp;
	zone_cmd_t zcmd;
	zone_t *zone;

	zone = curproc->p_zone;
	ASSERT(getzoneid() != GLOBAL_ZONEID);

	switch (cmd) {
	case A_SHUTDOWN:
		switch (fcn) {
		case AD_HALT:
		case AD_POWEROFF:
			zcmd = Z_HALT;
			break;
		case AD_BOOT:
			zcmd = Z_REBOOT;
			break;
		case AD_IBOOT:
		case AD_SBOOT:
		case AD_SIBOOT:
		case AD_NOSYNC:
			return (ENOTSUP);
		default:
			return (EINVAL);
		}
		break;
	case A_REBOOT:
		zcmd = Z_REBOOT;
		break;
	case A_FTRACE:
	case A_REMOUNT:
	case A_FREEZE:
	case A_DUMP:
		return (ENOTSUP);
	default:
		ASSERT(cmd != A_SWAPCTL);	/* handled by uadmin() */
		return (EINVAL);
	}

	if (secpolicy_zone_admin(credp, B_FALSE))
		return (EPERM);
	mutex_enter(&zone_status_lock);
	/*
	 * zone_status can't be ZONE_IS_EMPTY or higher since curproc
	 * is in the zone.
	 */
	ASSERT(zone_status_get(zone) < ZONE_IS_EMPTY);
	if (zone_status_get(zone) > ZONE_IS_RUNNING) {
		/*
		 * This zone is already on its way down.
		 */
		mutex_exit(&zone_status_lock);
		return (0);
	}
	/*
	 * Prevent future zone_enter()s
	 */
	zone_status_set(zone, ZONE_IS_SHUTTING_DOWN);
	mutex_exit(&zone_status_lock);

	/*
	 * Kill everyone now and call zoneadmd later.
	 * zone_ki_call_zoneadmd() will do a more thorough job of this
	 * later.
	 */
	killall(zone->zone_id);
	/*
	 * Now, create the thread to contact zoneadmd and do the rest of the
	 * work.  This thread can't be created in our zone otherwise
	 * zone_destroy() would deadlock.
	 */
	zargp = kmem_alloc(sizeof (*zargp), KM_SLEEP);
	zargp->arg.cmd = zcmd;
	zargp->arg.uniqid = zone->zone_uniqid;
	(void) strcpy(zargp->arg.locale, "C");
	zone_hold(zargp->zone = zone);

	(void) thread_create(NULL, 0, zone_ki_call_zoneadmd, zargp, 0, &p0,
	    TS_RUN, minclsyspri);
	exit(CLD_EXITED, 0);

	return (EINVAL);
}

/*
 * Entry point so kadmin(A_SHUTDOWN, ...) can set the global zone's
 * status to ZONE_IS_SHUTTING_DOWN.
 */
void
zone_shutdown_global(void)
{
	ASSERT(curproc->p_zone == global_zone);

	mutex_enter(&zone_status_lock);
	ASSERT(zone_status_get(global_zone) == ZONE_IS_RUNNING);
	zone_status_set(global_zone, ZONE_IS_SHUTTING_DOWN);
	mutex_exit(&zone_status_lock);
}

/*
 * Returns true if the named dataset is visible in the current zone.
 * The 'write' parameter is set to 1 if the dataset is also writable.
 */
int
zone_dataset_visible(const char *dataset, int *write)
{
	zone_dataset_t *zd;
	size_t len;
	zone_t *zone = curproc->p_zone;

	if (dataset[0] == '\0')
		return (0);

	/*
	 * Walk the list once, looking for datasets which match exactly, or
	 * specify a dataset underneath an exported dataset.  If found, return
	 * true and note that it is writable.
	 */
	for (zd = list_head(&zone->zone_datasets); zd != NULL;
	    zd = list_next(&zone->zone_datasets, zd)) {

		len = strlen(zd->zd_dataset);
		if (strlen(dataset) >= len &&
		    bcmp(dataset, zd->zd_dataset, len) == 0 &&
		    (dataset[len] == '\0' || dataset[len] == '/' ||
		    dataset[len] == '@')) {
			if (write)
				*write = 1;
			return (1);
		}
	}

	/*
	 * Walk the list a second time, searching for datasets which are parents
	 * of exported datasets.  These should be visible, but read-only.
	 *
	 * Note that we also have to support forms such as 'pool/dataset/', with
	 * a trailing slash.
	 */
	for (zd = list_head(&zone->zone_datasets); zd != NULL;
	    zd = list_next(&zone->zone_datasets, zd)) {

		len = strlen(dataset);
		if (dataset[len - 1] == '/')
			len--;	/* Ignore trailing slash */
		if (len < strlen(zd->zd_dataset) &&
		    bcmp(dataset, zd->zd_dataset, len) == 0 &&
		    zd->zd_dataset[len] == '/') {
			if (write)
				*write = 0;
			return (1);
		}
	}

	return (0);
}