[apple/xnu.git] / osfmk / kern / task.c

/*
 * Copyright (c) 2000-2010, 2015 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_FREE_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 *      File:   kern/task.c
 *      Author: Avadis Tevanian, Jr., Michael Wayne Young, David Golub,
 *              David Black
 *
 *      Task management primitives implementation.
 */
/*
 * Copyright (c) 1993 The University of Utah and
 * the Computer Systems Laboratory (CSL).  All rights reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
 * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
 * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * CSL requests users of this software to return to csl-dist@cs.utah.edu any
 * improvements that they make and grant CSL redistribution rights.
 *
 */
/*
 * NOTICE: This file was modified by McAfee Research in 2004 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 * Copyright (c) 2005 SPARTA, Inc.
 */

#include <mach/mach_types.h>
#include <mach/boolean.h>
#include <mach/host_priv.h>
#include <mach/machine/vm_types.h>
#include <mach/vm_param.h>
#include <mach/mach_vm.h>
#include <mach/semaphore.h>
#include <mach/task_info.h>
#include <mach/task_special_ports.h>

#include <ipc/ipc_importance.h>
#include <ipc/ipc_types.h>
#include <ipc/ipc_space.h>
#include <ipc/ipc_entry.h>
#include <ipc/ipc_hash.h>

#include <kern/kern_types.h>
#include <kern/mach_param.h>
#include <kern/misc_protos.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/coalition.h>
#include <kern/zalloc.h>
#include <kern/kalloc.h>
#include <kern/kern_cdata.h>
#include <kern/processor.h>
#include <kern/sched_prim.h>    /* for thread_wakeup */
#include <kern/ipc_tt.h>
#include <kern/host.h>
#include <kern/clock.h>
#include <kern/timer.h>
#include <kern/assert.h>
#include <kern/sync_lock.h>
#include <kern/affinity.h>
#include <kern/exc_resource.h>
#include <kern/machine.h>
#include <corpses/task_corpse.h>
#if CONFIG_TELEMETRY
#include <kern/telemetry.h>
#endif

#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>         /* for kernel_map, ipc_kernel_map */
#include <vm/vm_pageout.h>
#include <vm/vm_protos.h>
#include <vm/vm_purgeable_internal.h>

#include <sys/resource.h>
#include <sys/signalvar.h> /* for coredump */

/*
 * Exported interfaces
 */

#include <mach/task_server.h>
#include <mach/mach_host_server.h>
#include <mach/host_security_server.h>
#include <mach/mach_port_server.h>

#include <vm/vm_shared_region.h>

#include <libkern/OSDebug.h>
#include <libkern/OSAtomic.h>

#if CONFIG_ATM
#include <atm/atm_internal.h>
#endif

#include <kern/sfi.h>

#if KPERF
extern int kpc_force_all_ctrs(task_t, int);
#endif

uint32_t qos_override_mode;

task_t                  kernel_task;
zone_t                  task_zone;
lck_attr_t      task_lck_attr;
lck_grp_t       task_lck_grp;
lck_grp_attr_t  task_lck_grp_attr;

/* Flag set by core audio when audio is playing. Used to stifle EXC_RESOURCE generation when active. */
int audio_active = 0;

zinfo_usage_store_t tasks_tkm_private;
zinfo_usage_store_t tasks_tkm_shared;

/* A container to accumulate statistics for expired tasks */
expired_task_statistics_t               dead_task_statistics;
lck_spin_t              dead_task_statistics_lock;

ledger_template_t task_ledger_template = NULL;

struct _task_ledger_indices task_ledgers __attribute__((used)) =
        {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
         { 0 /* initialized at runtime */},
#ifdef CONFIG_BANK
         -1, -1,
#endif
        };

/* System sleep state */
boolean_t tasks_suspend_state;


void init_task_ledgers(void);
void task_footprint_exceeded(int warning, __unused const void *param0, __unused const void *param1);
void task_wakeups_rate_exceeded(int warning, __unused const void *param0, __unused const void *param1);
void __attribute__((noinline)) THIS_PROCESS_IS_CAUSING_TOO_MANY_WAKEUPS__SENDING_EXC_RESOURCE(void);
void __attribute__((noinline)) PROC_CROSSED_HIGH_WATERMARK__SEND_EXC_RESOURCE_AND_SUSPEND(int max_footprint_mb);

kern_return_t task_suspend_internal(task_t);
kern_return_t task_resume_internal(task_t);
static kern_return_t task_start_halt_locked(task_t task, boolean_t should_mark_corpse);


void proc_init_cpumon_params(void);
extern kern_return_t exception_deliver(thread_t, exception_type_t, mach_exception_data_t, mach_msg_type_number_t, struct exception_action *, lck_mtx_t *);

// Warn tasks when they hit 80% of their memory limit.
#define PHYS_FOOTPRINT_WARNING_LEVEL 80

#define TASK_WAKEUPS_MONITOR_DEFAULT_LIMIT              150 /* wakeups per second */
#define TASK_WAKEUPS_MONITOR_DEFAULT_INTERVAL   300 /* in seconds. */

/*
 * Level (in terms of percentage of the limit) at which the wakeups monitor triggers telemetry.
 *
 * (ie when the task's wakeups rate exceeds 70% of the limit, start taking user
 *  stacktraces, aka micro-stackshots)
 */
#define TASK_WAKEUPS_MONITOR_DEFAULT_USTACKSHOTS_TRIGGER        70

int task_wakeups_monitor_interval; /* In seconds. Time period over which wakeups rate is observed */
int task_wakeups_monitor_rate;     /* In hz. Maximum allowable wakeups per task before EXC_RESOURCE is sent */

int task_wakeups_monitor_ustackshots_trigger_pct; /* Percentage. Level at which we start gathering telemetry. */

int disable_exc_resource; /* Global override to supress EXC_RESOURCE for resource monitor violations. */

ledger_amount_t max_task_footprint = 0;  /* Per-task limit on physical memory consumption in bytes     */
int max_task_footprint_mb = 0;  /* Per-task limit on physical memory consumption in megabytes */

#if MACH_ASSERT
int pmap_ledgers_panic = 1;
#endif /* MACH_ASSERT */

int task_max = CONFIG_TASK_MAX; /* Max number of tasks */

int hwm_user_cores = 0; /* high watermark violations generate user core files */

#ifdef MACH_BSD
extern void     proc_getexecutableuuid(void *, unsigned char *, unsigned long);
extern int      proc_pid(struct proc *p);
extern int      proc_selfpid(void);
extern char     *proc_name_address(struct proc *p);
extern uint64_t get_dispatchqueue_offset_from_proc(void *);
#if CONFIG_JETSAM
extern void     proc_memstat_terminated(struct proc* p, boolean_t set);
extern void     memorystatus_on_ledger_footprint_exceeded(int warning, const int max_footprint_mb);
#endif
#endif
#if MACH_ASSERT
extern int pmap_ledgers_panic;
#endif /* MACH_ASSERT */

/* Forwards */

void            task_hold_locked(
                        task_t          task);
void            task_wait_locked(
                        task_t          task,
                        boolean_t       until_not_runnable);
void            task_release_locked(
                        task_t          task);
void            task_free(
                        task_t          task );
void            task_synchronizer_destroy_all(
                        task_t          task);

int check_for_tasksuspend(
                        task_t task);

void
task_backing_store_privileged(
                        task_t task)
{
        task_lock(task);
        task->priv_flags |= VM_BACKING_STORE_PRIV;
        task_unlock(task);
        return;
}


void
task_set_64bit(
                task_t task,
                boolean_t is64bit)
{
#if defined(__i386__) || defined(__x86_64__) || defined(__arm64__)
        thread_t thread;
#endif /* defined(__i386__) || defined(__x86_64__) || defined(__arm64__) */

        task_lock(task);

        if (is64bit) {
                if (task_has_64BitAddr(task))
                        goto out;
                task_set_64BitAddr(task);
        } else {
                if ( !task_has_64BitAddr(task))
                        goto out;
                task_clear_64BitAddr(task);
        }
        /* FIXME: On x86, the thread save state flavor can diverge from the
         * task's 64-bit feature flag due to the 32-bit/64-bit register save
         * state dichotomy. Since we can be pre-empted in this interval,
         * certain routines may observe the thread as being in an inconsistent
         * state with respect to its task's 64-bitness.
         */

#if defined(__i386__) || defined(__x86_64__) || defined(__arm64__)      
        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                thread_mtx_lock(thread);
                machine_thread_switch_addrmode(thread);
                thread_mtx_unlock(thread);
        }
#endif /* defined(__i386__) || defined(__x86_64__) || defined(__arm64__) */     

out:
        task_unlock(task);
}


void
task_set_dyld_info(task_t task, mach_vm_address_t addr, mach_vm_size_t size)
{
        task_lock(task);
        task->all_image_info_addr = addr;
        task->all_image_info_size = size;
        task_unlock(task);
}

void
task_atm_reset(__unused task_t task) {

#if CONFIG_ATM
        if (task->atm_context != NULL) {
                 atm_task_descriptor_destroy(task->atm_context);
                 task->atm_context = NULL;
        }
#endif

}

void
task_bank_reset(__unused task_t task) {

#if CONFIG_BANK
        if (task->bank_context != NULL) {
                 bank_task_destroy(task);
        }
#endif

}

/*
 * NOTE: This should only be called when the P_LINTRANSIT
 *       flag is set (the proc_trans lock is held) on the
 *       proc associated with the task.
 */
void
task_bank_init(__unused task_t task) {

#if CONFIG_BANK
        if (task->bank_context != NULL) {
                panic("Task bank init called with non null bank context for task: %p and bank_context: %p", task, task->bank_context);
        }
        bank_task_initialize(task);
#endif

}

#if TASK_REFERENCE_LEAK_DEBUG
#include <kern/btlog.h>

decl_simple_lock_data(static,task_ref_lock);
static btlog_t *task_ref_btlog;
#define TASK_REF_OP_INCR        0x1
#define TASK_REF_OP_DECR        0x2

#define TASK_REF_BTDEPTH        7

static void
task_ref_lock_lock(void *context)
{
        simple_lock((simple_lock_t)context);
}
static void
task_ref_lock_unlock(void *context)
{
        simple_unlock((simple_lock_t)context);
}

void
task_reference_internal(task_t task)
{
        void *       bt[TASK_REF_BTDEPTH];
        int             numsaved = 0;

        numsaved = OSBacktrace(bt, TASK_REF_BTDEPTH);
        
        (void)hw_atomic_add(&(task)->ref_count, 1);
        btlog_add_entry(task_ref_btlog, task, TASK_REF_OP_INCR,
                                        bt, numsaved);
}

uint32_t
task_deallocate_internal(task_t task)
{
        void *       bt[TASK_REF_BTDEPTH];
        int             numsaved = 0;

        numsaved = OSBacktrace(bt, TASK_REF_BTDEPTH);

        btlog_add_entry(task_ref_btlog, task, TASK_REF_OP_DECR,
                                        bt, numsaved);
        return hw_atomic_sub(&(task)->ref_count, 1);
}

#endif /* TASK_REFERENCE_LEAK_DEBUG */

void
task_init(void)
{

        lck_grp_attr_setdefault(&task_lck_grp_attr);
        lck_grp_init(&task_lck_grp, "task", &task_lck_grp_attr);
        lck_attr_setdefault(&task_lck_attr);
        lck_mtx_init(&tasks_threads_lock, &task_lck_grp, &task_lck_attr);

        task_zone = zinit(
                        sizeof(struct task),
                        task_max * sizeof(struct task),
                        TASK_CHUNK * sizeof(struct task),
                        "tasks");

        zone_change(task_zone, Z_NOENCRYPT, TRUE);

        /*
         * Configure per-task memory limit.
         * The boot-arg is interpreted as Megabytes,
         * and takes precedence over the device tree.
         * Setting the boot-arg to 0 disables task limits.
         */
        if (!PE_parse_boot_argn("max_task_pmem", &max_task_footprint_mb,
                        sizeof (max_task_footprint_mb))) {
                /*
                 * No limit was found in boot-args, so go look in the device tree.
                 */
                if (!PE_get_default("kern.max_task_pmem", &max_task_footprint_mb,
                                sizeof(max_task_footprint_mb))) {
                        /*
                         * No limit was found in device tree.
                         */
                        max_task_footprint_mb = 0;
                }
        }

        if (max_task_footprint_mb != 0) {
#if CONFIG_JETSAM
                if (max_task_footprint_mb < 50) {
                                printf("Warning: max_task_pmem %d below minimum.\n",
                                max_task_footprint_mb);
                                max_task_footprint_mb = 50;
                }
                printf("Limiting task physical memory footprint to %d MB\n",
                        max_task_footprint_mb);

                max_task_footprint = (ledger_amount_t)max_task_footprint_mb * 1024 * 1024; // Convert MB to bytes
#else
                printf("Warning: max_task_footprint specified, but jetsam not configured; ignoring.\n");
#endif
        }

#if MACH_ASSERT
        PE_parse_boot_argn("pmap_ledgers_panic", &pmap_ledgers_panic,
                          sizeof (pmap_ledgers_panic));
#endif /* MACH_ASSERT */

        if (!PE_parse_boot_argn("hwm_user_cores", &hwm_user_cores,
                        sizeof (hwm_user_cores))) {
                hwm_user_cores = 0;
        }

        if (PE_parse_boot_argn("qos_override_mode", &qos_override_mode, sizeof(qos_override_mode))) {
                printf("QOS override mode: 0x%08x\n", qos_override_mode);
        } else {
                qos_override_mode = QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE_BUT_SINGLE_MUTEX_OVERRIDE;
        }

        proc_init_cpumon_params();

        if (!PE_parse_boot_argn("task_wakeups_monitor_rate", &task_wakeups_monitor_rate, sizeof (task_wakeups_monitor_rate))) {
                task_wakeups_monitor_rate = TASK_WAKEUPS_MONITOR_DEFAULT_LIMIT;
        }

        if (!PE_parse_boot_argn("task_wakeups_monitor_interval", &task_wakeups_monitor_interval, sizeof (task_wakeups_monitor_interval))) {
                task_wakeups_monitor_interval = TASK_WAKEUPS_MONITOR_DEFAULT_INTERVAL;
        }

        if (!PE_parse_boot_argn("task_wakeups_monitor_ustackshots_trigger_pct", &task_wakeups_monitor_ustackshots_trigger_pct,
                sizeof (task_wakeups_monitor_ustackshots_trigger_pct))) {
                task_wakeups_monitor_ustackshots_trigger_pct = TASK_WAKEUPS_MONITOR_DEFAULT_USTACKSHOTS_TRIGGER;
        }

        if (!PE_parse_boot_argn("disable_exc_resource", &disable_exc_resource,
                sizeof (disable_exc_resource))) {
                disable_exc_resource = 0;
        }

/*
 * If we have coalitions, coalition_init() will call init_task_ledgers() as it
 * sets up the ledgers for the default coalition. If we don't have coalitions,
 * then we have to call it now.
 */
#if CONFIG_COALITIONS
        assert(task_ledger_template);
#else /* CONFIG_COALITIONS */
        init_task_ledgers();
#endif /* CONFIG_COALITIONS */

#if TASK_REFERENCE_LEAK_DEBUG
        simple_lock_init(&task_ref_lock, 0);
        task_ref_btlog = btlog_create(100000,
                                                                  TASK_REF_BTDEPTH,
                                                                  task_ref_lock_lock,
                                                                  task_ref_lock_unlock,
                                                                  &task_ref_lock);
        assert(task_ref_btlog);
#endif

        /*
         * Create the kernel task as the first task.
         */
#ifdef __LP64__
        if (task_create_internal(TASK_NULL, NULL, FALSE, TRUE, &kernel_task) != KERN_SUCCESS)
#else
        if (task_create_internal(TASK_NULL, NULL, FALSE, FALSE, &kernel_task) != KERN_SUCCESS)
#endif
                panic("task_init\n");

        vm_map_deallocate(kernel_task->map);
        kernel_task->map = kernel_map;
        lck_spin_init(&dead_task_statistics_lock, &task_lck_grp, &task_lck_attr);

}

/*
 * Create a task running in the kernel address space.  It may
 * have its own map of size mem_size and may have ipc privileges.
 */
kern_return_t
kernel_task_create(
        __unused task_t         parent_task,
        __unused vm_offset_t            map_base,
        __unused vm_size_t              map_size,
        __unused task_t         *child_task)
{
        return (KERN_INVALID_ARGUMENT);
}

kern_return_t
task_create(
        task_t                          parent_task,
        __unused ledger_port_array_t    ledger_ports,
        __unused mach_msg_type_number_t num_ledger_ports,
        __unused boolean_t              inherit_memory,
        __unused task_t                 *child_task)    /* OUT */
{
        if (parent_task == TASK_NULL)
                return(KERN_INVALID_ARGUMENT);

        /*
         * No longer supported: too many calls assume that a task has a valid
         * process attached.
         */
        return(KERN_FAILURE);
}

kern_return_t
host_security_create_task_token(
        host_security_t                 host_security,
        task_t                          parent_task,
        __unused security_token_t       sec_token,
        __unused audit_token_t          audit_token,
        __unused host_priv_t            host_priv,
        __unused ledger_port_array_t    ledger_ports,
        __unused mach_msg_type_number_t num_ledger_ports,
        __unused boolean_t              inherit_memory,
        __unused task_t                 *child_task)    /* OUT */
{
        if (parent_task == TASK_NULL)
                return(KERN_INVALID_ARGUMENT);

        if (host_security == HOST_NULL)
                return(KERN_INVALID_SECURITY);

        /*
         * No longer supported.
         */
        return(KERN_FAILURE);
}

/*
 * Task ledgers
 * ------------
 *
 * phys_footprint
 *   Physical footprint: This is the sum of:
 *     + (internal - alternate_accounting)
 *     + (internal_compressed - alternate_accounting_compressed)
 *     + iokit_mapped
 *     + purgeable_nonvolatile
 *     + purgeable_nonvolatile_compressed
 *
 * internal
 *   The task's anonymous memory, which on iOS is always resident.
 *
 * internal_compressed
 *   Amount of this task's internal memory which is held by the compressor.
 *   Such memory is no longer actually resident for the task [i.e., resident in its pmap],
 *   and could be either decompressed back into memory, or paged out to storage, depending
 *   on our implementation.
 *
 * iokit_mapped
 *   IOKit mappings: The total size of all IOKit mappings in this task, regardless of
     clean/dirty or internal/external state].
 *
 * alternate_accounting
 *   The number of internal dirty pages which are part of IOKit mappings. By definition, these pages
 *   are counted in both internal *and* iokit_mapped, so we must subtract them from the total to avoid
 *   double counting.
 */
void
init_task_ledgers(void)
{
        ledger_template_t t;
        
        assert(task_ledger_template == NULL);
        assert(kernel_task == TASK_NULL);

        if ((t = ledger_template_create("Per-task ledger")) == NULL)
                panic("couldn't create task ledger template");

        task_ledgers.cpu_time = ledger_entry_add(t, "cpu_time", "sched", "ns");
        task_ledgers.tkm_private = ledger_entry_add(t, "tkm_private",
            "physmem", "bytes");
        task_ledgers.tkm_shared = ledger_entry_add(t, "tkm_shared", "physmem",
            "bytes");
        task_ledgers.phys_mem = ledger_entry_add(t, "phys_mem", "physmem",
            "bytes");
        task_ledgers.wired_mem = ledger_entry_add(t, "wired_mem", "physmem",
            "bytes");
        task_ledgers.internal = ledger_entry_add(t, "internal", "physmem",
            "bytes");
        task_ledgers.iokit_mapped = ledger_entry_add(t, "iokit_mapped", "mappings",
            "bytes");
        task_ledgers.alternate_accounting = ledger_entry_add(t, "alternate_accounting", "physmem",
            "bytes");
        task_ledgers.alternate_accounting_compressed = ledger_entry_add(t, "alternate_accounting_compressed", "physmem",
            "bytes");
        task_ledgers.phys_footprint = ledger_entry_add(t, "phys_footprint", "physmem",
            "bytes");
        task_ledgers.internal_compressed = ledger_entry_add(t, "internal_compressed", "physmem",
            "bytes");
        task_ledgers.purgeable_volatile = ledger_entry_add(t, "purgeable_volatile", "physmem", "bytes");
        task_ledgers.purgeable_nonvolatile = ledger_entry_add(t, "purgeable_nonvolatile", "physmem", "bytes");
        task_ledgers.purgeable_volatile_compressed = ledger_entry_add(t, "purgeable_volatile_compress", "physmem", "bytes");
        task_ledgers.purgeable_nonvolatile_compressed = ledger_entry_add(t, "purgeable_nonvolatile_compress", "physmem", "bytes");
        task_ledgers.platform_idle_wakeups = ledger_entry_add(t, "platform_idle_wakeups", "power",
            "count");
        task_ledgers.interrupt_wakeups = ledger_entry_add(t, "interrupt_wakeups", "power",
            "count");
        
#if CONFIG_SCHED_SFI
        sfi_class_id_t class_id, ledger_alias;
        for (class_id = SFI_CLASS_UNSPECIFIED; class_id < MAX_SFI_CLASS_ID; class_id++) {
                task_ledgers.sfi_wait_times[class_id] = -1;
        }

        /* don't account for UNSPECIFIED */
        for (class_id = SFI_CLASS_UNSPECIFIED + 1; class_id < MAX_SFI_CLASS_ID; class_id++) {
                ledger_alias = sfi_get_ledger_alias_for_class(class_id);
                if (ledger_alias != SFI_CLASS_UNSPECIFIED) {
                        /* Check to see if alias has been registered yet */
                        if (task_ledgers.sfi_wait_times[ledger_alias] != -1) {
                                task_ledgers.sfi_wait_times[class_id] = task_ledgers.sfi_wait_times[ledger_alias];
                        } else {
                                /* Otherwise, initialize it first */
                                task_ledgers.sfi_wait_times[class_id] = task_ledgers.sfi_wait_times[ledger_alias] = sfi_ledger_entry_add(t, ledger_alias);
                        }
                } else {
                        task_ledgers.sfi_wait_times[class_id] = sfi_ledger_entry_add(t, class_id);
                }

                if (task_ledgers.sfi_wait_times[class_id] < 0) {
                        panic("couldn't create entries for task ledger template for SFI class 0x%x", class_id);
                }
        }

        assert(task_ledgers.sfi_wait_times[MAX_SFI_CLASS_ID -1] != -1);
#endif /* CONFIG_SCHED_SFI */

#ifdef CONFIG_BANK
        task_ledgers.cpu_time_billed_to_me = ledger_entry_add(t, "cpu_time_billed_to_me", "sched", "ns");
        task_ledgers.cpu_time_billed_to_others = ledger_entry_add(t, "cpu_time_billed_to_others", "sched", "ns");
#endif
        if ((task_ledgers.cpu_time < 0) ||
            (task_ledgers.tkm_private < 0) ||
            (task_ledgers.tkm_shared < 0) ||
            (task_ledgers.phys_mem < 0) ||
            (task_ledgers.wired_mem < 0) ||
            (task_ledgers.internal < 0) ||
            (task_ledgers.iokit_mapped < 0) ||
            (task_ledgers.alternate_accounting < 0) ||
            (task_ledgers.alternate_accounting_compressed < 0) ||
            (task_ledgers.phys_footprint < 0) ||
            (task_ledgers.internal_compressed < 0) ||
            (task_ledgers.purgeable_volatile < 0) ||
            (task_ledgers.purgeable_nonvolatile < 0) ||
            (task_ledgers.purgeable_volatile_compressed < 0) ||
            (task_ledgers.purgeable_nonvolatile_compressed < 0) ||
            (task_ledgers.platform_idle_wakeups < 0) ||
            (task_ledgers.interrupt_wakeups < 0)
#ifdef CONFIG_BANK
            || (task_ledgers.cpu_time_billed_to_me < 0) || (task_ledgers.cpu_time_billed_to_others < 0)
#endif
            ) {
                panic("couldn't create entries for task ledger template");
        }

        ledger_track_maximum(t, task_ledgers.phys_footprint, 60);
#if MACH_ASSERT
        if (pmap_ledgers_panic) {
                ledger_panic_on_negative(t, task_ledgers.phys_footprint);
                ledger_panic_on_negative(t, task_ledgers.internal);
                ledger_panic_on_negative(t, task_ledgers.internal_compressed);
                ledger_panic_on_negative(t, task_ledgers.iokit_mapped);
                ledger_panic_on_negative(t, task_ledgers.alternate_accounting);
                ledger_panic_on_negative(t, task_ledgers.alternate_accounting_compressed);
                ledger_panic_on_negative(t, task_ledgers.purgeable_volatile);
                ledger_panic_on_negative(t, task_ledgers.purgeable_nonvolatile);
                ledger_panic_on_negative(t, task_ledgers.purgeable_volatile_compressed);
                ledger_panic_on_negative(t, task_ledgers.purgeable_nonvolatile_compressed);
        }
#endif /* MACH_ASSERT */

#if CONFIG_JETSAM
        ledger_set_callback(t, task_ledgers.phys_footprint, task_footprint_exceeded, NULL, NULL);
#endif

        ledger_set_callback(t, task_ledgers.interrupt_wakeups,
                task_wakeups_rate_exceeded, NULL, NULL);
        
        task_ledger_template = t;
}

kern_return_t
task_create_internal(
        task_t          parent_task,
        coalition_t     *parent_coalitions __unused,
        boolean_t       inherit_memory,
        boolean_t       is_64bit,
        task_t          *child_task)            /* OUT */
{
        task_t                  new_task;
        vm_shared_region_t      shared_region;
        ledger_t                ledger = NULL;

        new_task = (task_t) zalloc(task_zone);

        if (new_task == TASK_NULL)
                return(KERN_RESOURCE_SHORTAGE);

        /* one ref for just being alive; one for our caller */
        new_task->ref_count = 2;

        /* allocate with active entries */
        assert(task_ledger_template != NULL);
        if ((ledger = ledger_instantiate(task_ledger_template,
                        LEDGER_CREATE_ACTIVE_ENTRIES)) == NULL) {
                zfree(task_zone, new_task);
                return(KERN_RESOURCE_SHORTAGE);
        }

        new_task->ledger = ledger;

#if defined(CONFIG_SCHED_MULTIQ)
        new_task->sched_group = sched_group_create();
#endif

        /* if inherit_memory is true, parent_task MUST not be NULL */
        if (inherit_memory)
                new_task->map = vm_map_fork(ledger, parent_task->map);
        else
                new_task->map = vm_map_create(pmap_create(ledger, 0, is_64bit),
                                (vm_map_offset_t)(VM_MIN_ADDRESS),
                                (vm_map_offset_t)(VM_MAX_ADDRESS), TRUE);

        /* Inherit memlock limit from parent */
        if (parent_task)
                vm_map_set_user_wire_limit(new_task->map, (vm_size_t)parent_task->map->user_wire_limit);

        lck_mtx_init(&new_task->lock, &task_lck_grp, &task_lck_attr);
        queue_init(&new_task->threads);
        new_task->suspend_count = 0;
        new_task->thread_count = 0;
        new_task->active_thread_count = 0;
        new_task->user_stop_count = 0;
        new_task->legacy_stop_count = 0;
        new_task->active = TRUE;
        new_task->halting = FALSE;
        new_task->user_data = NULL;
        new_task->faults = 0;
        new_task->cow_faults = 0;
        new_task->pageins = 0;
        new_task->messages_sent = 0;
        new_task->messages_received = 0;
        new_task->syscalls_mach = 0;
        new_task->priv_flags = 0;
        new_task->syscalls_unix=0;
        new_task->c_switch = new_task->p_switch = new_task->ps_switch = 0;
        new_task->t_flags = 0;
        new_task->importance = 0;

#if CONFIG_ATM
        new_task->atm_context = NULL;
#endif
#if CONFIG_BANK
        new_task->bank_context = NULL;
#endif

        zinfo_task_init(new_task);

#ifdef MACH_BSD
        new_task->bsd_info = NULL;
        new_task->corpse_info = NULL;
#endif /* MACH_BSD */

#if CONFIG_JETSAM
        if (max_task_footprint != 0) {
                ledger_set_limit(ledger, task_ledgers.phys_footprint, max_task_footprint, PHYS_FOOTPRINT_WARNING_LEVEL);
        }
#endif

        if (task_wakeups_monitor_rate != 0) {
                uint32_t flags = WAKEMON_ENABLE | WAKEMON_SET_DEFAULTS;
                int32_t  rate; // Ignored because of WAKEMON_SET_DEFAULTS
                task_wakeups_monitor_ctl(new_task, &flags, &rate);
        }

#if defined(__i386__) || defined(__x86_64__)
        new_task->i386_ldt = 0;
#endif

        new_task->task_debug = NULL;

        queue_init(&new_task->semaphore_list);
        new_task->semaphores_owned = 0;

        ipc_task_init(new_task, parent_task);

        new_task->total_user_time = 0;
        new_task->total_system_time = 0;

        new_task->vtimers = 0;

        new_task->shared_region = NULL;

        new_task->affinity_space = NULL;

        new_task->pidsuspended = FALSE;
        new_task->frozen = FALSE;
        new_task->changing_freeze_state = FALSE;
        new_task->rusage_cpu_flags = 0;
        new_task->rusage_cpu_percentage = 0;
        new_task->rusage_cpu_interval = 0;
        new_task->rusage_cpu_deadline = 0;
        new_task->rusage_cpu_callt = NULL;
#if MACH_ASSERT
        new_task->suspends_outstanding = 0;
#endif

#if HYPERVISOR
        new_task->hv_task_target = NULL;
#endif /* HYPERVISOR */


        new_task->low_mem_notified_warn = 0;
        new_task->low_mem_notified_critical = 0;
        new_task->low_mem_privileged_listener = 0;
        new_task->purged_memory_warn = 0;
        new_task->purged_memory_critical = 0;
        new_task->mem_notify_reserved = 0;
#if IMPORTANCE_INHERITANCE
        new_task->task_imp_base = NULL;
#endif /* IMPORTANCE_INHERITANCE */

#if     defined(__x86_64__)     
        new_task->uexc_range_start = new_task->uexc_range_size = new_task->uexc_handler = 0;
#endif

        new_task->requested_policy = default_task_requested_policy;
        new_task->effective_policy = default_task_effective_policy;
        new_task->pended_policy    = default_task_pended_policy;

        if (parent_task != TASK_NULL) {
                new_task->sec_token = parent_task->sec_token;
                new_task->audit_token = parent_task->audit_token;

                /* inherit the parent's shared region */
                shared_region = vm_shared_region_get(parent_task);
                vm_shared_region_set(new_task, shared_region);

                if(task_has_64BitAddr(parent_task))
                        task_set_64BitAddr(new_task);
                new_task->all_image_info_addr = parent_task->all_image_info_addr;
                new_task->all_image_info_size = parent_task->all_image_info_size;

#if defined(__i386__) || defined(__x86_64__)
                if (inherit_memory && parent_task->i386_ldt)
                        new_task->i386_ldt = user_ldt_copy(parent_task->i386_ldt);
#endif
                if (inherit_memory && parent_task->affinity_space)
                        task_affinity_create(parent_task, new_task);

                new_task->pset_hint = parent_task->pset_hint = task_choose_pset(parent_task);

#if IMPORTANCE_INHERITANCE
                ipc_importance_task_t new_task_imp = IIT_NULL;

                if (task_is_marked_importance_donor(parent_task)) {
                        new_task_imp = ipc_importance_for_task(new_task, FALSE);
                        assert(IIT_NULL != new_task_imp);
                        ipc_importance_task_mark_donor(new_task_imp, TRUE);
                }
                /* Embedded doesn't want this to inherit */
                if (task_is_marked_importance_receiver(parent_task)) {
                        if (IIT_NULL == new_task_imp)
                                new_task_imp = ipc_importance_for_task(new_task, FALSE);
                        assert(IIT_NULL != new_task_imp);
                        ipc_importance_task_mark_receiver(new_task_imp, TRUE);
                }
                if (task_is_marked_importance_denap_receiver(parent_task)) {
                        if (IIT_NULL == new_task_imp)
                                new_task_imp = ipc_importance_for_task(new_task, FALSE);
                        assert(IIT_NULL != new_task_imp);
                        ipc_importance_task_mark_denap_receiver(new_task_imp, TRUE);
                }
                
                if (IIT_NULL != new_task_imp) {
                        assert(new_task->task_imp_base == new_task_imp);
                        ipc_importance_task_release(new_task_imp);
                }
#endif /* IMPORTANCE_INHERITANCE */

                new_task->priority = BASEPRI_DEFAULT;
                new_task->max_priority = MAXPRI_USER;

                new_task->requested_policy.t_apptype     = parent_task->requested_policy.t_apptype;

                new_task->requested_policy.int_darwinbg  = parent_task->requested_policy.int_darwinbg;
                new_task->requested_policy.ext_darwinbg  = parent_task->requested_policy.ext_darwinbg;
                new_task->requested_policy.int_iotier    = parent_task->requested_policy.int_iotier;
                new_task->requested_policy.ext_iotier    = parent_task->requested_policy.ext_iotier;
                new_task->requested_policy.int_iopassive = parent_task->requested_policy.int_iopassive;
                new_task->requested_policy.ext_iopassive = parent_task->requested_policy.ext_iopassive;
                new_task->requested_policy.bg_iotier     = parent_task->requested_policy.bg_iotier;
                new_task->requested_policy.terminated    = parent_task->requested_policy.terminated;
                new_task->requested_policy.t_qos_clamp   = parent_task->requested_policy.t_qos_clamp;

                task_policy_create(new_task, parent_task->requested_policy.t_boosted);
        } else {
                new_task->sec_token = KERNEL_SECURITY_TOKEN;
                new_task->audit_token = KERNEL_AUDIT_TOKEN;
#ifdef __LP64__
                if(is_64bit)
                        task_set_64BitAddr(new_task);
#endif
                new_task->all_image_info_addr = (mach_vm_address_t)0;
                new_task->all_image_info_size = (mach_vm_size_t)0;

                new_task->pset_hint = PROCESSOR_SET_NULL;

                if (kernel_task == TASK_NULL) {
                        new_task->priority = BASEPRI_KERNEL;
                        new_task->max_priority = MAXPRI_KERNEL;
                } else {
                        new_task->priority = BASEPRI_DEFAULT;
                        new_task->max_priority = MAXPRI_USER;
                }
        }

        bzero(new_task->coalition, sizeof(new_task->coalition));
        for (int i = 0; i < COALITION_NUM_TYPES; i++)
                queue_chain_init(new_task->task_coalition[i]);

        /* Allocate I/O Statistics */
        new_task->task_io_stats = (io_stat_info_t)kalloc(sizeof(struct io_stat_info));
        assert(new_task->task_io_stats != NULL);
        bzero(new_task->task_io_stats, sizeof(struct io_stat_info));
        new_task->task_immediate_writes = 0;
        new_task->task_deferred_writes = 0;     
        new_task->task_invalidated_writes = 0;
        new_task->task_metadata_writes = 0;

        bzero(&(new_task->cpu_time_qos_stats), sizeof(struct _cpu_time_qos_stats));

        bzero(&new_task->extmod_statistics, sizeof(new_task->extmod_statistics));
        new_task->task_timer_wakeups_bin_1 = new_task->task_timer_wakeups_bin_2 = 0;
        new_task->task_gpu_ns = 0;

#if CONFIG_COALITIONS

        /* TODO: there is no graceful failure path here... */
        if (parent_coalitions && parent_coalitions[COALITION_TYPE_RESOURCE]) {
                coalitions_adopt_task(parent_coalitions, new_task);
        } else if (parent_task && parent_task->coalition[COALITION_TYPE_RESOURCE]) {
                /*
                 * all tasks at least have a resource coalition, so
                 * if the parent has one then inherit all coalitions
                 * the parent is a part of
                 */
                coalitions_adopt_task(parent_task->coalition, new_task);
        } else {
                /* TODO: assert that new_task will be PID 1 (launchd) */
                coalitions_adopt_init_task(new_task);
        }

        if (new_task->coalition[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
                panic("created task is not a member of a resource coalition");
        }
#endif /* CONFIG_COALITIONS */

        new_task->dispatchqueue_offset = 0;
        if (parent_task != NULL) {
                new_task->dispatchqueue_offset = parent_task->dispatchqueue_offset;
        }

        if (vm_backing_store_low && parent_task != NULL)
                new_task->priv_flags |= (parent_task->priv_flags&VM_BACKING_STORE_PRIV);

        new_task->task_volatile_objects = 0;
        new_task->task_nonvolatile_objects = 0;
        new_task->task_purgeable_disowning = FALSE;
        new_task->task_purgeable_disowned = FALSE;

        ipc_task_enable(new_task);

        lck_mtx_lock(&tasks_threads_lock);
        queue_enter(&tasks, new_task, task_t, tasks);
        tasks_count++;
        if (tasks_suspend_state) {
            task_suspend_internal(new_task);
        }
        lck_mtx_unlock(&tasks_threads_lock);

        *child_task = new_task;
        return(KERN_SUCCESS);
}

int task_dropped_imp_count = 0;

/*
 *      task_deallocate:
 *
 *      Drop a reference on a task.
 */
void
task_deallocate(
        task_t          task)
{
        ledger_amount_t credit, debit, interrupt_wakeups, platform_idle_wakeups;
        uint32_t refs;

        if (task == TASK_NULL)
            return;

        refs = task_deallocate_internal(task);

#if IMPORTANCE_INHERITANCE
        if (refs > 1)
                return;
        
        if (refs == 1) {
                /*
                 * If last ref potentially comes from the task's importance,
                 * disconnect it.  But more task refs may be added before
                 * that completes, so wait for the reference to go to zero
                 * naturually (it may happen on a recursive task_deallocate()
                 * from the ipc_importance_disconnect_task() call).
                 */
                if (IIT_NULL != task->task_imp_base)
                        ipc_importance_disconnect_task(task);
                return;
        }
#else
        if (refs > 0)
                return;
#endif /* IMPORTANCE_INHERITANCE */

        lck_mtx_lock(&tasks_threads_lock);
        queue_remove(&terminated_tasks, task, task_t, tasks);
        terminated_tasks_count--;
        lck_mtx_unlock(&tasks_threads_lock);

        /*
         * remove the reference on atm descriptor
         */
        task_atm_reset(task);

        /*
         * remove the reference on bank context
         */
        task_bank_reset(task);

        if (task->task_io_stats)
                kfree(task->task_io_stats, sizeof(struct io_stat_info));

        /*
         *      Give the machine dependent code a chance
         *      to perform cleanup before ripping apart
         *      the task.
         */
        machine_task_terminate(task);

        ipc_task_terminate(task);

        if (task->affinity_space)
                task_affinity_deallocate(task);

#if MACH_ASSERT
        if (task->ledger != NULL &&
            task->map != NULL &&
            task->map->pmap != NULL &&
            task->map->pmap->ledger != NULL) {
                assert(task->ledger == task->map->pmap->ledger);
        }
#endif /* MACH_ASSERT */

        vm_purgeable_disown(task);
        assert(task->task_purgeable_disowned);
        if (task->task_volatile_objects != 0 ||
            task->task_nonvolatile_objects != 0) {
                panic("task_deallocate(%p): "
                      "volatile_objects=%d nonvolatile_objects=%d\n",
                      task,
                      task->task_volatile_objects,
                      task->task_nonvolatile_objects);
        }

        vm_map_deallocate(task->map);
        is_release(task->itk_space);

        ledger_get_entries(task->ledger, task_ledgers.interrupt_wakeups,
                           &interrupt_wakeups, &debit);
        ledger_get_entries(task->ledger, task_ledgers.platform_idle_wakeups,
                           &platform_idle_wakeups, &debit);

#if defined(CONFIG_SCHED_MULTIQ)
        sched_group_destroy(task->sched_group);
#endif

        /* Accumulate statistics for dead tasks */
        lck_spin_lock(&dead_task_statistics_lock);
        dead_task_statistics.total_user_time += task->total_user_time;
        dead_task_statistics.total_system_time += task->total_system_time;

        dead_task_statistics.task_interrupt_wakeups += interrupt_wakeups;
        dead_task_statistics.task_platform_idle_wakeups += platform_idle_wakeups;

        dead_task_statistics.task_timer_wakeups_bin_1 += task->task_timer_wakeups_bin_1;
        dead_task_statistics.task_timer_wakeups_bin_2 += task->task_timer_wakeups_bin_2;

        lck_spin_unlock(&dead_task_statistics_lock);
        lck_mtx_destroy(&task->lock, &task_lck_grp);

        if (!ledger_get_entries(task->ledger, task_ledgers.tkm_private, &credit,
            &debit)) {
                OSAddAtomic64(credit, (int64_t *)&tasks_tkm_private.alloc);
                OSAddAtomic64(debit, (int64_t *)&tasks_tkm_private.free);
        }
        if (!ledger_get_entries(task->ledger, task_ledgers.tkm_shared, &credit,
            &debit)) {
                OSAddAtomic64(credit, (int64_t *)&tasks_tkm_shared.alloc);
                OSAddAtomic64(debit, (int64_t *)&tasks_tkm_shared.free);
        }
        ledger_dereference(task->ledger);
        zinfo_task_free(task);

#if TASK_REFERENCE_LEAK_DEBUG
        btlog_remove_entries_for_element(task_ref_btlog, task);
#endif

#if CONFIG_COALITIONS
        if (!task->coalition[COALITION_TYPE_RESOURCE])
                panic("deallocating task was not a member of a resource coalition");
        task_release_coalitions(task);
#endif /* CONFIG_COALITIONS */

        bzero(task->coalition, sizeof(task->coalition));

#if MACH_BSD
        /* clean up collected information since last reference to task is gone */
        if (task->corpse_info) {
                task_crashinfo_destroy(task->corpse_info);
                task->corpse_info = NULL;
        }
#endif

        zfree(task_zone, task);
}

/*
 *      task_name_deallocate:
 *
 *      Drop a reference on a task name.
 */
void
task_name_deallocate(
        task_name_t             task_name)
{
        return(task_deallocate((task_t)task_name));
}

/*
 *      task_suspension_token_deallocate:
 *
 *      Drop a reference on a task suspension token.
 */
void
task_suspension_token_deallocate(
        task_suspension_token_t         token)
{
        return(task_deallocate((task_t)token));
}


/*
 * task_collect_crash_info:
 *
 * collect crash info from bsd and mach based data
 */
kern_return_t
task_collect_crash_info(task_t task)
{
        kern_return_t kr = KERN_SUCCESS;

        kcdata_descriptor_t crash_data = NULL;
        kcdata_descriptor_t crash_data_release = NULL;
        mach_msg_type_number_t size = CORPSEINFO_ALLOCATION_SIZE;
        mach_vm_offset_t crash_data_user_ptr = 0;

        if (!corpses_enabled()) {
                return KERN_NOT_SUPPORTED;
        }

        task_lock(task);
        assert(task->bsd_info != NULL);
        if (task->corpse_info == NULL && task->bsd_info != NULL) {
                task_unlock(task);
                /* map crash data memory in task's vm map */
                kr = mach_vm_allocate(task->map, &crash_data_user_ptr, size, (VM_MAKE_TAG(VM_MEMORY_CORPSEINFO) | VM_FLAGS_ANYWHERE));

                if (kr != KERN_SUCCESS)
                        goto out_no_lock;

                crash_data = task_crashinfo_alloc_init((mach_vm_address_t)crash_data_user_ptr, size);
                if (crash_data) {
                        task_lock(task);
                        crash_data_release = task->corpse_info;
                        task->corpse_info = crash_data;
                        task_unlock(task);
                        kr = KERN_SUCCESS;
                } else {
                        /* if failed to create corpse info, free the mapping */
                        if (KERN_SUCCESS != mach_vm_deallocate(task->map, crash_data_user_ptr, size)) {
                                printf("mach_vm_deallocate failed to clear corpse_data for pid %d.\n", task_pid(task));
                        }
                        kr = KERN_FAILURE;
                }

                if (crash_data_release != NULL) {
                        task_crashinfo_destroy(crash_data_release);
                }
        } else {
                task_unlock(task);
        }

out_no_lock:
        return kr;
}

/*
 * task_deliver_crash_notification:
 *
 * Makes outcall to registered host port for a corpse.
 */
kern_return_t
task_deliver_crash_notification(task_t task)
{
        kcdata_descriptor_t crash_info = task->corpse_info;
        thread_t th_iter = NULL;
        kern_return_t kr = KERN_SUCCESS;
        wait_interrupt_t wsave;
        mach_exception_data_type_t code[EXCEPTION_CODE_MAX];

        if (crash_info == NULL)
                return KERN_FAILURE;

        code[0] = crash_info->kcd_addr_begin;
        code[1] = crash_info->kcd_length;

        task_lock(task);
        queue_iterate(&task->threads, th_iter, thread_t, task_threads)
        {
                ipc_thread_reset(th_iter);
        }
        task_unlock(task);

        wsave = thread_interrupt_level(THREAD_UNINT);
        kr = exception_triage(EXC_CORPSE_NOTIFY, code, EXCEPTION_CODE_MAX);
        if (kr != KERN_SUCCESS) {
                printf("Failed to send exception EXC_CORPSE_NOTIFY. error code: %d for pid %d\n", kr, task_pid(task));
        }

        /*
         * crash reporting is done. Now release threads
         * for reaping by thread_terminate_daemon
         */
        task_lock(task);
        assert(task->active_thread_count == 0);
        queue_iterate(&task->threads, th_iter, thread_t, task_threads)
        {
                thread_mtx_lock(th_iter);
                assert(th_iter->inspection == TRUE);
                th_iter->inspection = FALSE;
                /* now that the corpse has been autopsied, dispose of the thread name */
                uthread_cleanup_name(th_iter->uthread);
                thread_mtx_unlock(th_iter);
        }

        thread_terminate_crashed_threads();
        /* remove the pending corpse report flag */
        task_clear_corpse_pending_report(task);

        task_unlock(task);

        (void)thread_interrupt_level(wsave);
        task_terminate_internal(task);

        return kr;
}

/*
 *      task_terminate:
 *
 *      Terminate the specified task.  See comments on thread_terminate
 *      (kern/thread.c) about problems with terminating the "current task."
 */

kern_return_t
task_terminate(
        task_t          task)
{
        if (task == TASK_NULL)
                return (KERN_INVALID_ARGUMENT);

        if (task->bsd_info)
                return (KERN_FAILURE);

        return (task_terminate_internal(task));
}

#if MACH_ASSERT
extern int proc_pid(struct proc *);
extern void proc_name_kdp(task_t t, char *buf, int size);
#endif /* MACH_ASSERT */

#define VM_MAP_PARTIAL_REAP 0x54  /* 0x150 */
static void
__unused task_partial_reap(task_t task, __unused int pid)
{
        unsigned int    reclaimed_resident = 0;
        unsigned int    reclaimed_compressed = 0;
        uint64_t        task_page_count;

        task_page_count = (get_task_phys_footprint(task) / PAGE_SIZE_64);

        KERNEL_DEBUG_CONSTANT((MACHDBG_CODE(DBG_MACH_VM, VM_MAP_PARTIAL_REAP) | DBG_FUNC_START),
                              pid, task_page_count, 0, 0, 0);

        vm_map_partial_reap(task->map, &reclaimed_resident, &reclaimed_compressed);

        KERNEL_DEBUG_CONSTANT((MACHDBG_CODE(DBG_MACH_VM, VM_MAP_PARTIAL_REAP) | DBG_FUNC_END),
                              pid, reclaimed_resident, reclaimed_compressed, 0, 0);
}

kern_return_t
task_mark_corpse(task_t task)
{
        kern_return_t kr = KERN_SUCCESS;
        thread_t self_thread;
        (void) self_thread;
        wait_interrupt_t wsave;

        assert(task != kernel_task);
        assert(task == current_task());
        assert(!task_is_a_corpse(task));

        kr = task_collect_crash_info(task);
        if (kr != KERN_SUCCESS) {
                return kr;
        }

        self_thread = current_thread();

        wsave = thread_interrupt_level(THREAD_UNINT);
        task_lock(task);

        task_set_corpse_pending_report(task);
        task_set_corpse(task);

        kr = task_start_halt_locked(task, TRUE);
        assert(kr == KERN_SUCCESS);
        ipc_task_reset(task);
        ipc_task_enable(task);

        task_unlock(task);
        /* terminate the ipc space */
        ipc_space_terminate(task->itk_space);
        
        task_start_halt(task);
        thread_terminate_internal(self_thread);
        (void) thread_interrupt_level(wsave);
        assert(task->halting == TRUE);
        return kr;
}

kern_return_t
task_terminate_internal(
        task_t                  task)
{
        thread_t                        thread, self;
        task_t                          self_task;
        boolean_t                       interrupt_save;
        int                             pid = 0;

        assert(task != kernel_task);

        self = current_thread();
        self_task = self->task;

        /*
         *      Get the task locked and make sure that we are not racing
         *      with someone else trying to terminate us.
         */
        if (task == self_task)
                task_lock(task);
        else
        if (task < self_task) {
                task_lock(task);
                task_lock(self_task);
        }
        else {
                task_lock(self_task);
                task_lock(task);
        }

        if (!task->active) {
                /*
                 *      Task is already being terminated.
                 *      Just return an error. If we are dying, this will
                 *      just get us to our AST special handler and that
                 *      will get us to finalize the termination of ourselves.
                 */
                task_unlock(task);
                if (self_task != task)
                        task_unlock(self_task);

                return (KERN_FAILURE);
        }

        if (task_corpse_pending_report(task)) {
                /*
                 *      Task is marked for reporting as corpse.
                 *      Just return an error. This will
                 *      just get us to our AST special handler and that
                 *      will get us to finish the path to death
                 */
                task_unlock(task);
                if (self_task != task)
                        task_unlock(self_task);

                return (KERN_FAILURE);
        }

        if (self_task != task)
                task_unlock(self_task);

        /*
         * Make sure the current thread does not get aborted out of
         * the waits inside these operations.
         */
        interrupt_save = thread_interrupt_level(THREAD_UNINT);

        /*
         *      Indicate that we want all the threads to stop executing
         *      at user space by holding the task (we would have held
         *      each thread independently in thread_terminate_internal -
         *      but this way we may be more likely to already find it
         *      held there).  Mark the task inactive, and prevent
         *      further task operations via the task port.
         */
        task_hold_locked(task);
        task->active = FALSE;
        ipc_task_disable(task);

#if CONFIG_TELEMETRY
        /*
         * Notify telemetry that this task is going away.
         */
        telemetry_task_ctl_locked(task, TF_TELEMETRY, 0);
#endif

        /*
         *      Terminate each thread in the task.
         */
        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        thread_terminate_internal(thread);
        }

#ifdef MACH_BSD
        if (task->bsd_info != NULL) {
                pid = proc_pid(task->bsd_info);
        }
#endif /* MACH_BSD */

        task_unlock(task);

        proc_set_task_policy(task, THREAD_NULL, TASK_POLICY_ATTRIBUTE,
                             TASK_POLICY_TERMINATED, TASK_POLICY_ENABLE);

        /* Early object reap phase */

// PR-17045188: Revisit implementation
//        task_partial_reap(task, pid);


        /*
         *      Destroy all synchronizers owned by the task.
         */
        task_synchronizer_destroy_all(task);

        /*
         *      Destroy the IPC space, leaving just a reference for it.
         */
        ipc_space_terminate(task->itk_space);

#if 00
        /* if some ledgers go negative on tear-down again... */
        ledger_disable_panic_on_negative(task->map->pmap->ledger,
                                         task_ledgers.phys_footprint);
        ledger_disable_panic_on_negative(task->map->pmap->ledger,
                                         task_ledgers.internal);
        ledger_disable_panic_on_negative(task->map->pmap->ledger,
                                         task_ledgers.internal_compressed);
        ledger_disable_panic_on_negative(task->map->pmap->ledger,
                                         task_ledgers.iokit_mapped);
        ledger_disable_panic_on_negative(task->map->pmap->ledger,
                                         task_ledgers.alternate_accounting);
        ledger_disable_panic_on_negative(task->map->pmap->ledger,
                                         task_ledgers.alternate_accounting_compressed);
#endif

        /*
         * If the current thread is a member of the task
         * being terminated, then the last reference to
         * the task will not be dropped until the thread
         * is finally reaped.  To avoid incurring the
         * expense of removing the address space regions
         * at reap time, we do it explictly here.
         */

        vm_map_lock(task->map);
        vm_map_disable_hole_optimization(task->map);
        vm_map_unlock(task->map);

        vm_map_remove(task->map,
                      task->map->min_offset,
                      task->map->max_offset,
                      /* no unnesting on final cleanup: */
                      VM_MAP_REMOVE_NO_UNNESTING);

        /* release our shared region */
        vm_shared_region_set(task, NULL);


#if MACH_ASSERT
        /*
         * Identify the pmap's process, in case the pmap ledgers drift
         * and we have to report it.
         */
        char procname[17];
        if (task->bsd_info) {
                pid = proc_pid(task->bsd_info);
                proc_name_kdp(task, procname, sizeof (procname));
        } else {
                pid = 0;
                strlcpy(procname, "<unknown>", sizeof (procname));
        }
        pmap_set_process(task->map->pmap, pid, procname);
#endif /* MACH_ASSERT */

        lck_mtx_lock(&tasks_threads_lock);
        queue_remove(&tasks, task, task_t, tasks);
        queue_enter(&terminated_tasks, task, task_t, tasks);
        tasks_count--;
        terminated_tasks_count++;
        lck_mtx_unlock(&tasks_threads_lock);

        /*
         * We no longer need to guard against being aborted, so restore
         * the previous interruptible state.
         */
        thread_interrupt_level(interrupt_save);

#if KPERF
        /* force the task to release all ctrs */
        if (task->t_chud & TASK_KPC_FORCED_ALL_CTRS)
                kpc_force_all_ctrs(task, 0);
#endif

#if CONFIG_COALITIONS
        /*
         * Leave our coalitions. (drop activation but not reference)
         */
        coalitions_remove_task(task);
#endif

        /*
         * Get rid of the task active reference on itself.
         */
        task_deallocate(task);

        return (KERN_SUCCESS);
}

void
tasks_system_suspend(boolean_t suspend)
{
        task_t task;

        lck_mtx_lock(&tasks_threads_lock);
        assert(tasks_suspend_state != suspend);
        tasks_suspend_state = suspend;
        queue_iterate(&tasks, task, task_t, tasks) {
                if (task == kernel_task) {
                        continue;
                }
                suspend ? task_suspend_internal(task) : task_resume_internal(task);
        }
        lck_mtx_unlock(&tasks_threads_lock);
}

/*
 * task_start_halt:
 *
 *      Shut the current task down (except for the current thread) in
 *      preparation for dramatic changes to the task (probably exec).
 *      We hold the task and mark all other threads in the task for
 *      termination.
 */
kern_return_t
task_start_halt(task_t task)
{
        kern_return_t kr = KERN_SUCCESS;
        task_lock(task);
        kr = task_start_halt_locked(task, FALSE);
        task_unlock(task);
        return kr;
}

static kern_return_t
task_start_halt_locked(task_t task, boolean_t should_mark_corpse)
{
        thread_t thread, self;
        uint64_t dispatchqueue_offset;

        assert(task != kernel_task);

        self = current_thread();

        if (task != self->task)
                return (KERN_INVALID_ARGUMENT);

        if (task->halting || !task->active || !self->active) {
                /*
                 * Task or current thread is already being terminated.
                 * Hurry up and return out of the current kernel context
                 * so that we run our AST special handler to terminate
                 * ourselves.
                 */
                return (KERN_FAILURE);
        }

        task->halting = TRUE;

        /*
         * Mark all the threads to keep them from starting any more
         * user-level execution.  The thread_terminate_internal code
         * would do this on a thread by thread basis anyway, but this
         * gives us a better chance of not having to wait there.
         */
        task_hold_locked(task);
        dispatchqueue_offset = get_dispatchqueue_offset_from_proc(task->bsd_info);

        /*
         * Terminate all the other threads in the task.
         */
        queue_iterate(&task->threads, thread, thread_t, task_threads)
        {
                if (should_mark_corpse) {
                        thread_mtx_lock(thread);
                        thread->inspection = TRUE;
                        thread_mtx_unlock(thread);
                }
                if (thread != self)
                        thread_terminate_internal(thread);
        }
        task->dispatchqueue_offset = dispatchqueue_offset;

        task_release_locked(task);

        return KERN_SUCCESS;
}


/*
 * task_complete_halt:
 *
 *      Complete task halt by waiting for threads to terminate, then clean
 *      up task resources (VM, port namespace, etc...) and then let the
 *      current thread go in the (practically empty) task context.
 */
void
task_complete_halt(task_t task)
{
        task_lock(task);
        assert(task->halting);
        assert(task == current_task());

        /*
         *      Wait for the other threads to get shut down.
         *      When the last other thread is reaped, we'll be
         *      woken up.
         */
        if (task->thread_count > 1) {
                assert_wait((event_t)&task->halting, THREAD_UNINT);
                task_unlock(task);
                thread_block(THREAD_CONTINUE_NULL);
        } else {
                task_unlock(task);
        }

        /*
         *      Give the machine dependent code a chance
         *      to perform cleanup of task-level resources
         *      associated with the current thread before
         *      ripping apart the task.
         */
        machine_task_terminate(task);

        /*
         *      Destroy all synchronizers owned by the task.
         */
        task_synchronizer_destroy_all(task);

        /*
         *      Destroy the contents of the IPC space, leaving just
         *      a reference for it.
         */
        ipc_space_clean(task->itk_space);

        /*
         * Clean out the address space, as we are going to be
         * getting a new one.
         */
        vm_map_remove(task->map, task->map->min_offset,
                      task->map->max_offset,
                      /* no unnesting on final cleanup: */
                      VM_MAP_REMOVE_NO_UNNESTING);

        task->halting = FALSE;
}

/*
 *      task_hold_locked:
 *
 *      Suspend execution of the specified task.
 *      This is a recursive-style suspension of the task, a count of
 *      suspends is maintained.
 *
 *      CONDITIONS: the task is locked and active.
 */
void
task_hold_locked(
        register task_t         task)
{
        register thread_t       thread;

        assert(task->active);

        if (task->suspend_count++ > 0)
                return;

        /*
         *      Iterate through all the threads and hold them.
         */
        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                thread_mtx_lock(thread);
                thread_hold(thread);
                thread_mtx_unlock(thread);
        }
}

/*
 *      task_hold:
 *
 *      Same as the internal routine above, except that is must lock
 *      and verify that the task is active.  This differs from task_suspend
 *      in that it places a kernel hold on the task rather than just a 
 *      user-level hold.  This keeps users from over resuming and setting
 *      it running out from under the kernel.
 *
 *      CONDITIONS: the caller holds a reference on the task
 */
kern_return_t
task_hold(
        register task_t         task)
{
        if (task == TASK_NULL)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);

        if (!task->active) {
                task_unlock(task);

                return (KERN_FAILURE);
        }

        task_hold_locked(task);
        task_unlock(task);

        return (KERN_SUCCESS);
}

kern_return_t
task_wait(
                task_t          task,
                boolean_t       until_not_runnable)
{
        if (task == TASK_NULL)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);

        if (!task->active) {
                task_unlock(task);

                return (KERN_FAILURE);
        }

        task_wait_locked(task, until_not_runnable);
        task_unlock(task);

        return (KERN_SUCCESS);
}

/*
 *      task_wait_locked:
 *
 *      Wait for all threads in task to stop.
 *
 * Conditions:
 *      Called with task locked, active, and held.
 */
void
task_wait_locked(
        register task_t         task,
        boolean_t               until_not_runnable)
{
        register thread_t       thread, self;

        assert(task->active);
        assert(task->suspend_count > 0);

        self = current_thread();

        /*
         *      Iterate through all the threads and wait for them to
         *      stop.  Do not wait for the current thread if it is within
         *      the task.
         */
        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                if (thread != self)
                        thread_wait(thread, until_not_runnable);
        }
}

/*
 *      task_release_locked:
 *
 *      Release a kernel hold on a task.
 *
 *      CONDITIONS: the task is locked and active
 */
void
task_release_locked(
        register task_t         task)
{
        register thread_t       thread;

        assert(task->active);
        assert(task->suspend_count > 0);

        if (--task->suspend_count > 0)
                return;

        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                thread_mtx_lock(thread);
                thread_release(thread);
                thread_mtx_unlock(thread);
        }
}

/*
 *      task_release:
 *
 *      Same as the internal routine above, except that it must lock
 *      and verify that the task is active.
 *
 *      CONDITIONS: The caller holds a reference to the task
 */
kern_return_t
task_release(
        task_t          task)
{
        if (task == TASK_NULL)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);

        if (!task->active) {
                task_unlock(task);

                return (KERN_FAILURE);
        }

        task_release_locked(task);
        task_unlock(task);

        return (KERN_SUCCESS);
}

kern_return_t
task_threads(
        task_t                                  task,
        thread_act_array_t              *threads_out,
        mach_msg_type_number_t  *count)
{
        mach_msg_type_number_t  actual;
        thread_t                                *thread_list;
        thread_t                                thread;
        vm_size_t                               size, size_needed;
        void                                    *addr;
        unsigned int                    i, j;

        if (task == TASK_NULL)
                return (KERN_INVALID_ARGUMENT);

        size = 0; addr = NULL;

        for (;;) {
                task_lock(task);
                if (!task->active) {
                        task_unlock(task);

                        if (size != 0)
                                kfree(addr, size);

                        return (KERN_FAILURE);
                }

                actual = task->thread_count;

                /* do we have the memory we need? */
                size_needed = actual * sizeof (mach_port_t);
                if (size_needed <= size)
                        break;

                /* unlock the task and allocate more memory */
                task_unlock(task);

                if (size != 0)
                        kfree(addr, size);

                assert(size_needed > 0);
                size = size_needed;

                addr = kalloc(size);
                if (addr == 0)
                        return (KERN_RESOURCE_SHORTAGE);
        }

        /* OK, have memory and the task is locked & active */
        thread_list = (thread_t *)addr;

        i = j = 0;

        for (thread = (thread_t)queue_first(&task->threads); i < actual;
                                ++i, thread = (thread_t)queue_next(&thread->task_threads)) {
                thread_reference_internal(thread);
                thread_list[j++] = thread;
        }

        assert(queue_end(&task->threads, (queue_entry_t)thread));

        actual = j;
        size_needed = actual * sizeof (mach_port_t);

        /* can unlock task now that we've got the thread refs */
        task_unlock(task);

        if (actual == 0) {
                /* no threads, so return null pointer and deallocate memory */

                *threads_out = NULL;
                *count = 0;

                if (size != 0)
                        kfree(addr, size);
        }
        else {
                /* if we allocated too much, must copy */

                if (size_needed < size) {
                        void *newaddr;

                        newaddr = kalloc(size_needed);
                        if (newaddr == 0) {
                                for (i = 0; i < actual; ++i)
                                        thread_deallocate(thread_list[i]);
                                kfree(addr, size);
                                return (KERN_RESOURCE_SHORTAGE);
                        }

                        bcopy(addr, newaddr, size_needed);
                        kfree(addr, size);
                        thread_list = (thread_t *)newaddr;
                }

                *threads_out = thread_list;
                *count = actual;

                /* do the conversion that Mig should handle */

                for (i = 0; i < actual; ++i)
                        ((ipc_port_t *) thread_list)[i] = convert_thread_to_port(thread_list[i]);
        }

        return (KERN_SUCCESS);
}

#define TASK_HOLD_NORMAL        0
#define TASK_HOLD_PIDSUSPEND    1
#define TASK_HOLD_LEGACY        2
#define TASK_HOLD_LEGACY_ALL    3

static kern_return_t
place_task_hold    (
        register task_t task,
        int mode)
{    
        if (!task->active) {
                return (KERN_FAILURE);
        }

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            MACHDBG_CODE(DBG_MACH_IPC,MACH_TASK_SUSPEND) | DBG_FUNC_NONE,
            task_pid(task), ((thread_t)queue_first(&task->threads))->thread_id,
            task->user_stop_count, task->user_stop_count + 1, 0);

#if MACH_ASSERT
        current_task()->suspends_outstanding++;
#endif

        if (mode == TASK_HOLD_LEGACY)
                task->legacy_stop_count++;

        if (task->user_stop_count++ > 0) {
                /*
                 *      If the stop count was positive, the task is
                 *      already stopped and we can exit.
                 */
                return (KERN_SUCCESS);
        }

        /*
         * Put a kernel-level hold on the threads in the task (all
         * user-level task suspensions added together represent a
         * single kernel-level hold).  We then wait for the threads
         * to stop executing user code.
         */
        task_hold_locked(task);
        task_wait_locked(task, FALSE);
        
        return (KERN_SUCCESS);
}

static kern_return_t
release_task_hold    (
        register task_t         task,
        int                     mode)
{
        register boolean_t release = FALSE;
    
        if (!task->active) {
                return (KERN_FAILURE);
        }
        
        if (mode == TASK_HOLD_PIDSUSPEND) {
            if (task->pidsuspended == FALSE) {
                    return (KERN_FAILURE);
            }
            task->pidsuspended = FALSE;
        }

        if (task->user_stop_count > (task->pidsuspended ? 1 : 0)) {

                KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
                    MACHDBG_CODE(DBG_MACH_IPC,MACH_TASK_RESUME) | DBG_FUNC_NONE,
                    task_pid(task), ((thread_t)queue_first(&task->threads))->thread_id,
                    task->user_stop_count, mode, task->legacy_stop_count);

#if MACH_ASSERT
                /*
                 * This is obviously not robust; if we suspend one task and then resume a different one,
                 * we'll fly under the radar. This is only meant to catch the common case of a crashed
                 * or buggy suspender.
                 */
                current_task()->suspends_outstanding--;
#endif

                if (mode == TASK_HOLD_LEGACY_ALL) {
                        if (task->legacy_stop_count >= task->user_stop_count) {
                                task->user_stop_count = 0;
                                release = TRUE;
                        } else {
                                task->user_stop_count -= task->legacy_stop_count;
                        }
                        task->legacy_stop_count = 0;
                } else {
                        if (mode == TASK_HOLD_LEGACY && task->legacy_stop_count > 0)
                                task->legacy_stop_count--;
                        if (--task->user_stop_count == 0)
                                release = TRUE;
                }
        }
        else {
                return (KERN_FAILURE);
        }

        /*
         *      Release the task if necessary.
         */
        if (release)
                task_release_locked(task);
                
    return (KERN_SUCCESS);
}


/*
 *      task_suspend:
 *
 *      Implement an (old-fashioned) user-level suspension on a task.
 *
 *      Because the user isn't expecting to have to manage a suspension
 *      token, we'll track it for him in the kernel in the form of a naked
 *      send right to the task's resume port.  All such send rights
 *      account for a single suspension against the task (unlike task_suspend2()
 *      where each caller gets a unique suspension count represented by a
 *      unique send-once right).
 *
 * Conditions:
 *      The caller holds a reference to the task
 */
kern_return_t
task_suspend(
        register task_t         task)
{
        kern_return_t                   kr;
        mach_port_t                     port, send, old_notify;
        mach_port_name_t                name;

        if (task == TASK_NULL || task == kernel_task)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);

        /* 
         * Claim a send right on the task resume port, and request a no-senders
         * notification on that port (if none outstanding). 
         */
        if (task->itk_resume == IP_NULL) {
                task->itk_resume = ipc_port_alloc_kernel();
                if (!IP_VALID(task->itk_resume))
                        panic("failed to create resume port");
                ipc_kobject_set(task->itk_resume, (ipc_kobject_t)task, IKOT_TASK_RESUME);
        }

        port = task->itk_resume;
        ip_lock(port);
        assert(ip_active(port));

        send = ipc_port_make_send_locked(port);
        assert(IP_VALID(send));

        if (port->ip_nsrequest == IP_NULL) {
                ipc_port_nsrequest(port, port->ip_mscount, ipc_port_make_sonce_locked(port), &old_notify);
                assert(old_notify == IP_NULL);
                /* port unlocked */
        } else {
                ip_unlock(port);
        }

        /*
         * place a legacy hold on the task.
         */
        kr = place_task_hold(task, TASK_HOLD_LEGACY);
        if (kr != KERN_SUCCESS) {
                task_unlock(task);
                ipc_port_release_send(send);
                return kr;
        }

        task_unlock(task);

        /*
         * Copyout the send right into the calling task's IPC space.  It won't know it is there,
         * but we'll look it up when calling a traditional resume.  Any IPC operations that
         * deallocate the send right will auto-release the suspension.
         */
        if ((kr = ipc_kmsg_copyout_object(current_task()->itk_space, (ipc_object_t)send,
                MACH_MSG_TYPE_MOVE_SEND, &name)) != KERN_SUCCESS) {
                printf("warning: %s(%d) failed to copyout suspension token for pid %d with error: %d\n",
                                proc_name_address(current_task()->bsd_info), proc_pid(current_task()->bsd_info),
                                task_pid(task), kr);
                return (kr);
        }

        return (kr);
}

/*
 *      task_resume:
 *              Release a user hold on a task.
 *              
 * Conditions:
 *              The caller holds a reference to the task
 */
kern_return_t 
task_resume(
        register task_t task)
{
        kern_return_t    kr;
        mach_port_name_t resume_port_name;
        ipc_entry_t              resume_port_entry;
        ipc_space_t              space = current_task()->itk_space;

        if (task == TASK_NULL || task == kernel_task )
                return (KERN_INVALID_ARGUMENT);

        /* release a legacy task hold */
        task_lock(task);
        kr = release_task_hold(task, TASK_HOLD_LEGACY);
        task_unlock(task);

        is_write_lock(space);
        if (is_active(space) && IP_VALID(task->itk_resume) &&
            ipc_hash_lookup(space, (ipc_object_t)task->itk_resume, &resume_port_name, &resume_port_entry) == TRUE) {
                /*
                 * We found a suspension token in the caller's IPC space. Release a send right to indicate that
                 * we are holding one less legacy hold on the task from this caller.  If the release failed,
                 * go ahead and drop all the rights, as someone either already released our holds or the task
                 * is gone.
                 */
                if (kr == KERN_SUCCESS)
                        ipc_right_dealloc(space, resume_port_name, resume_port_entry);
                else
                        ipc_right_destroy(space, resume_port_name, resume_port_entry, FALSE, 0);
                /* space unlocked */
        } else {
                is_write_unlock(space);
                if (kr == KERN_SUCCESS)
                        printf("warning: %s(%d) performed out-of-band resume on pid %d\n",
                               proc_name_address(current_task()->bsd_info), proc_pid(current_task()->bsd_info),
                               task_pid(task));
        }

        return kr;
}

/*
 * Suspend the target task.
 * Making/holding a token/reference/port is the callers responsibility.
 */
kern_return_t
task_suspend_internal(task_t task)
{
        kern_return_t    kr;
       
        if (task == TASK_NULL || task == kernel_task)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);
        kr = place_task_hold(task, TASK_HOLD_NORMAL);
        task_unlock(task);
        return (kr);
}

/*
 * Suspend the target task, and return a suspension token. The token
 * represents a reference on the suspended task.
 */
kern_return_t
task_suspend2(
        register task_t                 task,
        task_suspension_token_t *suspend_token)
{
        kern_return_t    kr;
 
        kr = task_suspend_internal(task);
        if (kr != KERN_SUCCESS) {
                *suspend_token = TASK_NULL;
                return (kr);
        }

        /*
         * Take a reference on the target task and return that to the caller
         * as a "suspension token," which can be converted into an SO right to
         * the now-suspended task's resume port.
         */
        task_reference_internal(task);
        *suspend_token = task;

        return (KERN_SUCCESS);
}

/*
 * Resume the task
 * (reference/token/port management is caller's responsibility).
 */
kern_return_t
task_resume_internal(
        register task_suspension_token_t                task)
{
        kern_return_t kr;

        if (task == TASK_NULL || task == kernel_task)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);
        kr = release_task_hold(task, TASK_HOLD_NORMAL);
        task_unlock(task);
        return (kr);
}

/*
 * Resume the task using a suspension token. Consumes the token's ref.
 */
kern_return_t
task_resume2(
        register task_suspension_token_t                task)
{
        kern_return_t kr;

        kr = task_resume_internal(task);
        task_suspension_token_deallocate(task);

        return (kr);
}

boolean_t
task_suspension_notify(mach_msg_header_t *request_header)
{
        ipc_port_t port = (ipc_port_t) request_header->msgh_remote_port;
        task_t task = convert_port_to_task_suspension_token(port);
        mach_msg_type_number_t not_count;

        if (task == TASK_NULL || task == kernel_task)
                return TRUE;  /* nothing to do */

        switch (request_header->msgh_id) {

        case MACH_NOTIFY_SEND_ONCE:
                /* release the hold held by this specific send-once right */
                task_lock(task);
                release_task_hold(task, TASK_HOLD_NORMAL);
                task_unlock(task);
                break;

        case MACH_NOTIFY_NO_SENDERS:
                not_count = ((mach_no_senders_notification_t *)request_header)->not_count;

                task_lock(task);
                ip_lock(port);
                if (port->ip_mscount == not_count) {

                        /* release all the [remaining] outstanding legacy holds */
                        assert(port->ip_nsrequest == IP_NULL);
                        ip_unlock(port);
                        release_task_hold(task, TASK_HOLD_LEGACY_ALL);
                        task_unlock(task);

                } else if (port->ip_nsrequest == IP_NULL) {
                        ipc_port_t old_notify;

                        task_unlock(task);
                        /* new send rights, re-arm notification at current make-send count */
                        ipc_port_nsrequest(port, port->ip_mscount, ipc_port_make_sonce_locked(port), &old_notify);
                        assert(old_notify == IP_NULL);
                        /* port unlocked */
                } else {
                        ip_unlock(port);
                        task_unlock(task);
                }
                break;

        default:
                break;
        }

        task_suspension_token_deallocate(task); /* drop token reference */
        return TRUE;
}

kern_return_t
task_pidsuspend_locked(task_t task)
{
        kern_return_t kr;

        if (task->pidsuspended) {
                kr = KERN_FAILURE;
                goto out;
        }

        task->pidsuspended = TRUE;

        kr = place_task_hold(task, TASK_HOLD_PIDSUSPEND);
        if (kr != KERN_SUCCESS) {
                task->pidsuspended = FALSE;
        }
out:
        return(kr);
}


/*
 *      task_pidsuspend:
 *
 *      Suspends a task by placing a hold on its threads.
 *
 * Conditions:
 *      The caller holds a reference to the task
 */
kern_return_t
task_pidsuspend(
        register task_t         task)
{
        kern_return_t    kr;
    
        if (task == TASK_NULL || task == kernel_task)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);

        kr = task_pidsuspend_locked(task);

        task_unlock(task);

        return (kr);
}

/* If enabled, we bring all the frozen pages back in prior to resumption; otherwise, they're faulted back in on demand */
#define THAW_ON_RESUME 1

/*
 *      task_pidresume:
 *              Resumes a previously suspended task.
 *              
 * Conditions:
 *              The caller holds a reference to the task
 */
kern_return_t 
task_pidresume(
        register task_t task)
{
        kern_return_t    kr;

        if (task == TASK_NULL || task == kernel_task)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);
        
#if (CONFIG_FREEZE && THAW_ON_RESUME)

        while (task->changing_freeze_state) {

                assert_wait((event_t)&task->changing_freeze_state, THREAD_UNINT);
                task_unlock(task);
                thread_block(THREAD_CONTINUE_NULL);

                task_lock(task);
        }
        task->changing_freeze_state = TRUE;
#endif

        kr = release_task_hold(task, TASK_HOLD_PIDSUSPEND);

        task_unlock(task);

#if (CONFIG_FREEZE && THAW_ON_RESUME)
        if ((kr == KERN_SUCCESS) && (task->frozen == TRUE)) {

                if (COMPRESSED_PAGER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_ACTIVE) {

                        kr = KERN_SUCCESS;
                } else {

                        kr = vm_map_thaw(task->map);
                }
        }
        task_lock(task);

        if (kr == KERN_SUCCESS)
                task->frozen = FALSE;
        task->changing_freeze_state = FALSE;
        thread_wakeup(&task->changing_freeze_state);
        
        task_unlock(task);
#endif

        return (kr);
}

#if CONFIG_FREEZE

/*
 *      task_freeze:
 *
 *      Freeze a task.
 *
 * Conditions:
 *      The caller holds a reference to the task
 */
extern void             vm_wake_compactor_swapper();
extern queue_head_t     c_swapout_list_head;

kern_return_t
task_freeze(
        register task_t    task,
        uint32_t           *purgeable_count,
        uint32_t           *wired_count,
        uint32_t           *clean_count,
        uint32_t           *dirty_count,
        uint32_t           dirty_budget,
        boolean_t          *shared,
        boolean_t          walk_only)
{
        kern_return_t kr;
    
        if (task == TASK_NULL || task == kernel_task)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);

        while (task->changing_freeze_state) {

                assert_wait((event_t)&task->changing_freeze_state, THREAD_UNINT);
                task_unlock(task);
                thread_block(THREAD_CONTINUE_NULL);

                task_lock(task);
        }
        if (task->frozen) {
                task_unlock(task);
                return (KERN_FAILURE);
        }
        task->changing_freeze_state = TRUE;

        task_unlock(task);

        if (walk_only) {
                kr = vm_map_freeze_walk(task->map, purgeable_count, wired_count, clean_count, dirty_count, dirty_budget, shared);               
        } else {
                kr = vm_map_freeze(task->map, purgeable_count, wired_count, clean_count, dirty_count, dirty_budget, shared);
        }

        task_lock(task);

        if (walk_only == FALSE && kr == KERN_SUCCESS)
                task->frozen = TRUE;
        task->changing_freeze_state = FALSE;
        thread_wakeup(&task->changing_freeze_state);
        
        task_unlock(task);

        if (COMPRESSED_PAGER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_ACTIVE) {
                vm_wake_compactor_swapper();
                /*
                 * We do an explicit wakeup of the swapout thread here
                 * because the compact_and_swap routines don't have
                 * knowledge about these kind of "per-task packed c_segs"
                 * and so will not be evaluating whether we need to do
                 * a wakeup there.
                 */
                thread_wakeup((event_t)&c_swapout_list_head);
        }

        return (kr);
}

/*
 *      task_thaw:
 *
 *      Thaw a currently frozen task.
 *
 * Conditions:
 *      The caller holds a reference to the task
 */
kern_return_t
task_thaw(
        register task_t         task)
{
        kern_return_t kr;
    
        if (task == TASK_NULL || task == kernel_task)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);
        
        while (task->changing_freeze_state) {

                assert_wait((event_t)&task->changing_freeze_state, THREAD_UNINT);
                task_unlock(task);
                thread_block(THREAD_CONTINUE_NULL);

                task_lock(task);
        }
        if (!task->frozen) {
                task_unlock(task);
                return (KERN_FAILURE);
        }
        task->changing_freeze_state = TRUE;

        if (DEFAULT_PAGER_IS_ACTIVE || DEFAULT_FREEZER_IS_ACTIVE) {
                task_unlock(task);

                kr = vm_map_thaw(task->map);

                task_lock(task);
        
                if (kr == KERN_SUCCESS)
                        task->frozen = FALSE;
        } else {
                task->frozen = FALSE;
                kr = KERN_SUCCESS;
        }

        task->changing_freeze_state = FALSE;
        thread_wakeup(&task->changing_freeze_state);
        
        task_unlock(task);

        if (COMPRESSED_PAGER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_ACTIVE) {
                vm_wake_compactor_swapper();
        }

        return (kr);
}

#endif /* CONFIG_FREEZE */

kern_return_t
host_security_set_task_token(
        host_security_t  host_security,
        task_t           task,
        security_token_t sec_token,
        audit_token_t    audit_token,
        host_priv_t      host_priv)
{
        ipc_port_t       host_port;
        kern_return_t    kr;

        if (task == TASK_NULL)
                return(KERN_INVALID_ARGUMENT);

        if (host_security == HOST_NULL)
                return(KERN_INVALID_SECURITY);

        task_lock(task);
        task->sec_token = sec_token;
        task->audit_token = audit_token;

        task_unlock(task);

        if (host_priv != HOST_PRIV_NULL) {
                kr = host_get_host_priv_port(host_priv, &host_port);
        } else {
                kr = host_get_host_port(host_priv_self(), &host_port);
        }
        assert(kr == KERN_SUCCESS);
        kr = task_set_special_port(task, TASK_HOST_PORT, host_port);
        return(kr);
}

kern_return_t
task_send_trace_memory(
        task_t        target_task,
        __unused uint32_t pid,
        __unused uint64_t uniqueid)
{
        kern_return_t kr = KERN_INVALID_ARGUMENT;
        if (target_task == TASK_NULL)
                return (KERN_INVALID_ARGUMENT);

#if CONFIG_ATM
        kr = atm_send_proc_inspect_notification(target_task,
                                  pid,
                                  uniqueid);

#endif
        return (kr);
}
/*
 * This routine was added, pretty much exclusively, for registering the
 * RPC glue vector for in-kernel short circuited tasks.  Rather than
 * removing it completely, I have only disabled that feature (which was
 * the only feature at the time).  It just appears that we are going to
 * want to add some user data to tasks in the future (i.e. bsd info,
 * task names, etc...), so I left it in the formal task interface.
 */
kern_return_t
task_set_info(
        task_t          task,
        task_flavor_t   flavor,
        __unused task_info_t    task_info_in,           /* pointer to IN array */
        __unused mach_msg_type_number_t task_info_count)
{
        if (task == TASK_NULL)
                return(KERN_INVALID_ARGUMENT);

        switch (flavor) {

#if CONFIG_ATM
                case TASK_TRACE_MEMORY_INFO:
                {
                        if (task_info_count != TASK_TRACE_MEMORY_INFO_COUNT)
                                return (KERN_INVALID_ARGUMENT);
                        
                        assert(task_info_in != NULL);
                        task_trace_memory_info_t mem_info;
                        mem_info = (task_trace_memory_info_t) task_info_in;
                        kern_return_t kr = atm_register_trace_memory(task,
                                                mem_info->user_memory_address,
                                                mem_info->buffer_size);
                        return kr;
                        break;
                }

#endif
            default:
                return (KERN_INVALID_ARGUMENT);
        }
        return (KERN_SUCCESS);
}

int radar_20146450 = 1;
kern_return_t
task_info(
        task_t                  task,
        task_flavor_t           flavor,
        task_info_t             task_info_out,
        mach_msg_type_number_t  *task_info_count)
{
        kern_return_t error = KERN_SUCCESS;

        if (task == TASK_NULL)
                return (KERN_INVALID_ARGUMENT);

        task_lock(task);

        if ((task != current_task()) && (!task->active)) {
                task_unlock(task);
                return (KERN_INVALID_ARGUMENT);
        }

        switch (flavor) {

        case TASK_BASIC_INFO_32:
        case TASK_BASIC2_INFO_32:
        {
                task_basic_info_32_t    basic_info;
                vm_map_t                                map;
                clock_sec_t                             secs;
                clock_usec_t                    usecs;

                if (*task_info_count < TASK_BASIC_INFO_32_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                basic_info = (task_basic_info_32_t)task_info_out;

                map = (task == kernel_task)? kernel_map: task->map;
                basic_info->virtual_size = (typeof(basic_info->virtual_size))map->size;
                if (flavor == TASK_BASIC2_INFO_32) {
                        /*
                         * The "BASIC2" flavor gets the maximum resident
                         * size instead of the current resident size...
                         */
                        basic_info->resident_size = pmap_resident_max(map->pmap);
                } else {
                        basic_info->resident_size = pmap_resident_count(map->pmap);
                }
                basic_info->resident_size *= PAGE_SIZE;

                basic_info->policy = ((task != kernel_task)?
                                                                                  POLICY_TIMESHARE: POLICY_RR);
                basic_info->suspend_count = task->user_stop_count;

                absolutetime_to_microtime(task->total_user_time, &secs, &usecs);
                basic_info->user_time.seconds = 
                        (typeof(basic_info->user_time.seconds))secs;
                basic_info->user_time.microseconds = usecs;

                absolutetime_to_microtime(task->total_system_time, &secs, &usecs);
                basic_info->system_time.seconds = 
                        (typeof(basic_info->system_time.seconds))secs;
                basic_info->system_time.microseconds = usecs;

                *task_info_count = TASK_BASIC_INFO_32_COUNT;
                break;
        }

        case TASK_BASIC_INFO_64:
        {
                task_basic_info_64_t    basic_info;
                vm_map_t                                map;
                clock_sec_t                             secs;
                clock_usec_t                    usecs;

                if (*task_info_count < TASK_BASIC_INFO_64_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                basic_info = (task_basic_info_64_t)task_info_out;

                map = (task == kernel_task)? kernel_map: task->map;
                basic_info->virtual_size  = map->size;
                basic_info->resident_size =
                        (mach_vm_size_t)(pmap_resident_count(map->pmap))
                        * PAGE_SIZE_64;

                basic_info->policy = ((task != kernel_task)?
                                                                                  POLICY_TIMESHARE: POLICY_RR);
                basic_info->suspend_count = task->user_stop_count;

                absolutetime_to_microtime(task->total_user_time, &secs, &usecs);
                basic_info->user_time.seconds = 
                        (typeof(basic_info->user_time.seconds))secs;
                basic_info->user_time.microseconds = usecs;

                absolutetime_to_microtime(task->total_system_time, &secs, &usecs);
                basic_info->system_time.seconds =
                        (typeof(basic_info->system_time.seconds))secs;
                basic_info->system_time.microseconds = usecs;

                *task_info_count = TASK_BASIC_INFO_64_COUNT;
                break;
        }

        case MACH_TASK_BASIC_INFO:
        {
                mach_task_basic_info_t  basic_info;
                vm_map_t                map;
                clock_sec_t             secs;
                clock_usec_t            usecs;

                if (*task_info_count < MACH_TASK_BASIC_INFO_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                basic_info = (mach_task_basic_info_t)task_info_out;

                map = (task == kernel_task) ? kernel_map : task->map;

                basic_info->virtual_size  = map->size;

                basic_info->resident_size =
                    (mach_vm_size_t)(pmap_resident_count(map->pmap));
                basic_info->resident_size *= PAGE_SIZE_64;

                basic_info->resident_size_max =
                    (mach_vm_size_t)(pmap_resident_max(map->pmap));
                basic_info->resident_size_max *= PAGE_SIZE_64;

                basic_info->policy = ((task != kernel_task) ? 
                                      POLICY_TIMESHARE : POLICY_RR);

                basic_info->suspend_count = task->user_stop_count;

                absolutetime_to_microtime(task->total_user_time, &secs, &usecs);
                basic_info->user_time.seconds = 
                    (typeof(basic_info->user_time.seconds))secs;
                basic_info->user_time.microseconds = usecs;

                absolutetime_to_microtime(task->total_system_time, &secs, &usecs);
                basic_info->system_time.seconds =
                    (typeof(basic_info->system_time.seconds))secs;
                basic_info->system_time.microseconds = usecs;

                *task_info_count = MACH_TASK_BASIC_INFO_COUNT;
                break;
        }

        case TASK_THREAD_TIMES_INFO:
        {
                register task_thread_times_info_t       times_info;
                register thread_t                                       thread;

                if (*task_info_count < TASK_THREAD_TIMES_INFO_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                times_info = (task_thread_times_info_t) task_info_out;
                times_info->user_time.seconds = 0;
                times_info->user_time.microseconds = 0;
                times_info->system_time.seconds = 0;
                times_info->system_time.microseconds = 0;


                queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        time_value_t    user_time, system_time;

                        if (thread->options & TH_OPT_IDLE_THREAD)
                                continue;

                        thread_read_times(thread, &user_time, &system_time);

                        time_value_add(&times_info->user_time, &user_time);
                        time_value_add(&times_info->system_time, &system_time);
                }

                *task_info_count = TASK_THREAD_TIMES_INFO_COUNT;
                break;
        }

        case TASK_ABSOLUTETIME_INFO:
        {
                task_absolutetime_info_t        info;
                register thread_t                       thread;

                if (*task_info_count < TASK_ABSOLUTETIME_INFO_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                info = (task_absolutetime_info_t)task_info_out;
                info->threads_user = info->threads_system = 0;


                info->total_user = task->total_user_time;
                info->total_system = task->total_system_time;

                queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        uint64_t        tval;
                        spl_t           x;

                        if (thread->options & TH_OPT_IDLE_THREAD)
                                continue;

                        x = splsched();
                        thread_lock(thread);

                        tval = timer_grab(&thread->user_timer);
                        info->threads_user += tval;
                        info->total_user += tval;

                        tval = timer_grab(&thread->system_timer);
                        if (thread->precise_user_kernel_time) {
                                info->threads_system += tval;
                                info->total_system += tval;
                        } else {
                                /* system_timer may represent either sys or user */
                                info->threads_user += tval;
                                info->total_user += tval;
                        }

                        thread_unlock(thread);
                        splx(x);
                }


                *task_info_count = TASK_ABSOLUTETIME_INFO_COUNT;
                break;
        }

        case TASK_DYLD_INFO:
        {
                task_dyld_info_t info;

                /*
                 * We added the format field to TASK_DYLD_INFO output.  For
                 * temporary backward compatibility, accept the fact that
                 * clients may ask for the old version - distinquished by the
                 * size of the expected result structure.
                 */
#define TASK_LEGACY_DYLD_INFO_COUNT \
                offsetof(struct task_dyld_info, all_image_info_format)/sizeof(natural_t)

                if (*task_info_count < TASK_LEGACY_DYLD_INFO_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                info = (task_dyld_info_t)task_info_out;
                info->all_image_info_addr = task->all_image_info_addr;
                info->all_image_info_size = task->all_image_info_size;

                /* only set format on output for those expecting it */
                if (*task_info_count >= TASK_DYLD_INFO_COUNT) {
                        info->all_image_info_format = task_has_64BitAddr(task) ?
                                                 TASK_DYLD_ALL_IMAGE_INFO_64 : 
                                                 TASK_DYLD_ALL_IMAGE_INFO_32 ;
                        *task_info_count = TASK_DYLD_INFO_COUNT;
                } else {
                        *task_info_count = TASK_LEGACY_DYLD_INFO_COUNT;
                }
                break;
        }

        case TASK_EXTMOD_INFO:
        {
                task_extmod_info_t info;
                void *p;

                if (*task_info_count < TASK_EXTMOD_INFO_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                info = (task_extmod_info_t)task_info_out;

                p = get_bsdtask_info(task);
                if (p) {
                        proc_getexecutableuuid(p, info->task_uuid, sizeof(info->task_uuid));
                } else {
                        bzero(info->task_uuid, sizeof(info->task_uuid));
                }
                info->extmod_statistics = task->extmod_statistics;
                *task_info_count = TASK_EXTMOD_INFO_COUNT;

                break;
        }

        case TASK_KERNELMEMORY_INFO:
        {
                task_kernelmemory_info_t        tkm_info;
                ledger_amount_t                 credit, debit;

                if (*task_info_count < TASK_KERNELMEMORY_INFO_COUNT) {
                   error = KERN_INVALID_ARGUMENT;
                   break;
                }

                tkm_info = (task_kernelmemory_info_t) task_info_out;
                tkm_info->total_palloc = 0;
                tkm_info->total_pfree = 0;
                tkm_info->total_salloc = 0;
                tkm_info->total_sfree = 0;

                if (task == kernel_task) {
                        /*
                         * All shared allocs/frees from other tasks count against
                         * the kernel private memory usage.  If we are looking up
                         * info for the kernel task, gather from everywhere.
                         */
                        task_unlock(task);

                        /* start by accounting for all the terminated tasks against the kernel */
                        tkm_info->total_palloc = tasks_tkm_private.alloc + tasks_tkm_shared.alloc;
                        tkm_info->total_pfree = tasks_tkm_private.free + tasks_tkm_shared.free;

                        /* count all other task/thread shared alloc/free against the kernel */
                        lck_mtx_lock(&tasks_threads_lock);

                        /* XXX this really shouldn't be using the function parameter 'task' as a local var! */
                        queue_iterate(&tasks, task, task_t, tasks) {
                                if (task == kernel_task) {
                                        if (ledger_get_entries(task->ledger,
                                            task_ledgers.tkm_private, &credit,
                                            &debit) == KERN_SUCCESS) {
                                                tkm_info->total_palloc += credit;
                                                tkm_info->total_pfree += debit;
                                        }
                                }
                                if (!ledger_get_entries(task->ledger,
                                    task_ledgers.tkm_shared, &credit, &debit)) {
                                        tkm_info->total_palloc += credit;
                                        tkm_info->total_pfree += debit;
                                }
                        }
                        lck_mtx_unlock(&tasks_threads_lock);
                } else {
                        if (!ledger_get_entries(task->ledger,
                            task_ledgers.tkm_private, &credit, &debit)) {
                                tkm_info->total_palloc = credit;
                                tkm_info->total_pfree = debit;
                        }
                        if (!ledger_get_entries(task->ledger,
                            task_ledgers.tkm_shared, &credit, &debit)) {
                                tkm_info->total_salloc = credit;
                                tkm_info->total_sfree = debit;
                        }
                        task_unlock(task);
                }

                *task_info_count = TASK_KERNELMEMORY_INFO_COUNT;
                return KERN_SUCCESS;
        }

        /* OBSOLETE */
        case TASK_SCHED_FIFO_INFO:
        {

                if (*task_info_count < POLICY_FIFO_BASE_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                error = KERN_INVALID_POLICY;
                break;
        }

        /* OBSOLETE */
        case TASK_SCHED_RR_INFO:
        {
                register policy_rr_base_t       rr_base;
                uint32_t quantum_time;
                uint64_t quantum_ns;

                if (*task_info_count < POLICY_RR_BASE_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                rr_base = (policy_rr_base_t) task_info_out;

                if (task != kernel_task) {
                        error = KERN_INVALID_POLICY;
                        break;
                }

                rr_base->base_priority = task->priority;

                quantum_time = SCHED(initial_quantum_size)(THREAD_NULL);
                absolutetime_to_nanoseconds(quantum_time, &quantum_ns);
                
                rr_base->quantum = (uint32_t)(quantum_ns / 1000 / 1000);

                *task_info_count = POLICY_RR_BASE_COUNT;
                break;
        }

        /* OBSOLETE */
        case TASK_SCHED_TIMESHARE_INFO:
        {
                register policy_timeshare_base_t        ts_base;

                if (*task_info_count < POLICY_TIMESHARE_BASE_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                ts_base = (policy_timeshare_base_t) task_info_out;

                if (task == kernel_task) {
                        error = KERN_INVALID_POLICY;
                        break;
                }

                ts_base->base_priority = task->priority;

                *task_info_count = POLICY_TIMESHARE_BASE_COUNT;
                break;
        }

        case TASK_SECURITY_TOKEN:
        {
                register security_token_t       *sec_token_p;

                if (*task_info_count < TASK_SECURITY_TOKEN_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                sec_token_p = (security_token_t *) task_info_out;

                *sec_token_p = task->sec_token;

                *task_info_count = TASK_SECURITY_TOKEN_COUNT;
                break;
        }
            
        case TASK_AUDIT_TOKEN:
        {
                register audit_token_t  *audit_token_p;

                if (*task_info_count < TASK_AUDIT_TOKEN_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                audit_token_p = (audit_token_t *) task_info_out;

                *audit_token_p = task->audit_token;

                *task_info_count = TASK_AUDIT_TOKEN_COUNT;
                break;
        }
            
        case TASK_SCHED_INFO:
                error = KERN_INVALID_ARGUMENT;
                break;

        case TASK_EVENTS_INFO:
        {
                register task_events_info_t     events_info;
                register thread_t                       thread;

                if (*task_info_count < TASK_EVENTS_INFO_COUNT) {
                   error = KERN_INVALID_ARGUMENT;
                   break;
                }

                events_info = (task_events_info_t) task_info_out;


                events_info->faults = task->faults;
                events_info->pageins = task->pageins;
                events_info->cow_faults = task->cow_faults;
                events_info->messages_sent = task->messages_sent;
                events_info->messages_received = task->messages_received;
                events_info->syscalls_mach = task->syscalls_mach;
                events_info->syscalls_unix = task->syscalls_unix;

                events_info->csw = task->c_switch;

                queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        events_info->csw           += thread->c_switch;
                        events_info->syscalls_mach += thread->syscalls_mach;
                        events_info->syscalls_unix += thread->syscalls_unix;
                }


                *task_info_count = TASK_EVENTS_INFO_COUNT;
                break;
        }
        case TASK_AFFINITY_TAG_INFO:
        {
                if (*task_info_count < TASK_AFFINITY_TAG_INFO_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                error = task_affinity_info(task, task_info_out, task_info_count);
                break;
        }
        case TASK_POWER_INFO:
        {
                if (*task_info_count < TASK_POWER_INFO_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                task_power_info_locked(task, (task_power_info_t)task_info_out, NULL);
                break;
        }

        case TASK_POWER_INFO_V2:
        {
                if (*task_info_count < TASK_POWER_INFO_V2_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }
                task_power_info_v2_t tpiv2 = (task_power_info_v2_t) task_info_out;
                task_power_info_locked(task, &tpiv2->cpu_energy, &tpiv2->gpu_energy);
                break;
        }

        case TASK_VM_INFO:
        case TASK_VM_INFO_PURGEABLE:
        {
                task_vm_info_t          vm_info;
                vm_map_t                map;

                if (*task_info_count < TASK_VM_INFO_REV0_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                vm_info = (task_vm_info_t)task_info_out;

                if (task == kernel_task) {
                        map = kernel_map;
                        /* no lock */
                } else {
                        map = task->map;
                        vm_map_lock_read(map);
                }

                vm_info->virtual_size = (typeof(vm_info->virtual_size))map->size;
                vm_info->region_count = map->hdr.nentries;
                vm_info->page_size = vm_map_page_size(map);

                vm_info->resident_size = pmap_resident_count(map->pmap);
                vm_info->resident_size *= PAGE_SIZE;
                vm_info->resident_size_peak = pmap_resident_max(map->pmap);
                vm_info->resident_size_peak *= PAGE_SIZE;

#define _VM_INFO(_name) \
        vm_info->_name = ((mach_vm_size_t) map->pmap->stats._name) * PAGE_SIZE

                _VM_INFO(device);
                _VM_INFO(device_peak);
                _VM_INFO(external);
                _VM_INFO(external_peak);
                _VM_INFO(internal);
                _VM_INFO(internal_peak);
                _VM_INFO(reusable);
                _VM_INFO(reusable_peak);
                _VM_INFO(compressed);
                _VM_INFO(compressed_peak);
                _VM_INFO(compressed_lifetime);

                vm_info->purgeable_volatile_pmap = 0;
                vm_info->purgeable_volatile_resident = 0;
                vm_info->purgeable_volatile_virtual = 0;
                if (task == kernel_task) {
                        /*
                         * We do not maintain the detailed stats for the
                         * kernel_pmap, so just count everything as
                         * "internal"...
                         */
                        vm_info->internal = vm_info->resident_size;
                        /*
                         * ... but since the memory held by the VM compressor
                         * in the kernel address space ought to be attributed
                         * to user-space tasks, we subtract it from "internal"
                         * to give memory reporting tools a more accurate idea
                         * of what the kernel itself is actually using, instead
                         * of making it look like the kernel is leaking memory
                         * when the system is under memory pressure.
                         */
                        vm_info->internal -= (VM_PAGE_COMPRESSOR_COUNT *
                                              PAGE_SIZE);
                } else {
                        mach_vm_size_t  volatile_virtual_size;
                        mach_vm_size_t  volatile_resident_size;
                        mach_vm_size_t  volatile_compressed_size;
                        mach_vm_size_t  volatile_pmap_size;
                        mach_vm_size_t  volatile_compressed_pmap_size;
                        kern_return_t   kr;

                        if (flavor == TASK_VM_INFO_PURGEABLE) {
                                kr = vm_map_query_volatile(
                                        map,
                                        &volatile_virtual_size,
                                        &volatile_resident_size,
                                        &volatile_compressed_size,
                                        &volatile_pmap_size,
                                        &volatile_compressed_pmap_size);
                                if (kr == KERN_SUCCESS) {
                                        vm_info->purgeable_volatile_pmap =
                                                volatile_pmap_size;
                                        if (radar_20146450) {
                                        vm_info->compressed -=
                                                volatile_compressed_pmap_size;
                                        }
                                        vm_info->purgeable_volatile_resident =
                                                volatile_resident_size;
                                        vm_info->purgeable_volatile_virtual =
                                                volatile_virtual_size;
                                }
                        }
                        vm_map_unlock_read(map);
                }

                if (*task_info_count >= TASK_VM_INFO_COUNT) {
                        vm_info->phys_footprint = 0;
                        *task_info_count = TASK_VM_INFO_COUNT;
                } else {
                        *task_info_count = TASK_VM_INFO_REV0_COUNT;
                }

                break;
        }

        case TASK_WAIT_STATE_INFO:
        {
                /* 
                 * Deprecated flavor. Currently allowing some results until all users 
                 * stop calling it. The results may not be accurate.
         */
                task_wait_state_info_t  wait_state_info;
                uint64_t total_sfi_ledger_val = 0;

                if (*task_info_count < TASK_WAIT_STATE_INFO_COUNT) {
                   error = KERN_INVALID_ARGUMENT;
                   break;
                }

                wait_state_info = (task_wait_state_info_t) task_info_out;

                wait_state_info->total_wait_state_time = 0;
                bzero(wait_state_info->_reserved, sizeof(wait_state_info->_reserved));

#if CONFIG_SCHED_SFI
                int i, prev_lentry = -1;
                int64_t  val_credit, val_debit;

                for (i = 0; i < MAX_SFI_CLASS_ID; i++){
                        val_credit =0;
                        /*
                         * checking with prev_lentry != entry ensures adjacent classes 
                         * which share the same ledger do not add wait times twice.
                         * Note: Use ledger() call to get data for each individual sfi class.
                         */
                        if (prev_lentry != task_ledgers.sfi_wait_times[i] &&
                                KERN_SUCCESS == ledger_get_entries(task->ledger, 
                                                task_ledgers.sfi_wait_times[i], &val_credit, &val_debit)) {
                                total_sfi_ledger_val += val_credit;
                        }
                        prev_lentry = task_ledgers.sfi_wait_times[i];
                }

#endif /* CONFIG_SCHED_SFI */
                wait_state_info->total_wait_sfi_state_time = total_sfi_ledger_val; 
                *task_info_count = TASK_WAIT_STATE_INFO_COUNT;

                break;
        }
        case TASK_VM_INFO_PURGEABLE_ACCOUNT:
        {
#if DEVELOPMENT || DEBUG
                pvm_account_info_t      acnt_info;

                if (*task_info_count < PVM_ACCOUNT_INFO_COUNT) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                if (task_info_out == NULL) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }

                acnt_info = (pvm_account_info_t) task_info_out;

                error = vm_purgeable_account(task, acnt_info);

                *task_info_count = PVM_ACCOUNT_INFO_COUNT;

                break;
#else /* DEVELOPMENT || DEBUG */
                error = KERN_NOT_SUPPORTED;
                break;
#endif /* DEVELOPMENT || DEBUG */
        }
        case TASK_FLAGS_INFO:
        {
                task_flags_info_t               flags_info;

                if (*task_info_count < TASK_FLAGS_INFO_COUNT) {
                    error = KERN_INVALID_ARGUMENT;
                    break;
                }

                flags_info = (task_flags_info_t)task_info_out;

                /* only publish the 64-bit flag of the task */
                flags_info->flags = task->t_flags & TF_64B_ADDR;

                *task_info_count = TASK_FLAGS_INFO_COUNT;
                break;
        }

        case TASK_DEBUG_INFO_INTERNAL:
        {
#if DEVELOPMENT || DEBUG
                task_debug_info_internal_t dbg_info;
                if (*task_info_count < TASK_DEBUG_INFO_INTERNAL_COUNT) {
                        error = KERN_NOT_SUPPORTED;
                        break;
                }

                if (task_info_out == NULL) {
                        error = KERN_INVALID_ARGUMENT;
                        break;
                }
                dbg_info = (task_debug_info_internal_t) task_info_out;
                dbg_info->ipc_space_size = 0;
                if (task->itk_space){
                        dbg_info->ipc_space_size = task->itk_space->is_table_size;
                }

                error = KERN_SUCCESS;
                *task_info_count = TASK_DEBUG_INFO_INTERNAL_COUNT;
                break;
#else /* DEVELOPMENT || DEBUG */
                error = KERN_NOT_SUPPORTED;
                break;
#endif /* DEVELOPMENT || DEBUG */
        }
        default:
                error = KERN_INVALID_ARGUMENT;
        }

        task_unlock(task);
        return (error);
}

/* 
 *      task_power_info
 *
 *      Returns power stats for the task.
 *      Note: Called with task locked.
 */
void
task_power_info_locked(
        task_t                  task,
        task_power_info_t       info,
        gpu_energy_data_t       ginfo)
{
        thread_t                thread;
        ledger_amount_t         tmp;

        task_lock_assert_owned(task);

        ledger_get_entries(task->ledger, task_ledgers.interrupt_wakeups,
                (ledger_amount_t *)&info->task_interrupt_wakeups, &tmp);
        ledger_get_entries(task->ledger, task_ledgers.platform_idle_wakeups,
                (ledger_amount_t *)&info->task_platform_idle_wakeups, &tmp);

        info->task_timer_wakeups_bin_1 = task->task_timer_wakeups_bin_1;
        info->task_timer_wakeups_bin_2 = task->task_timer_wakeups_bin_2;

        info->total_user = task->total_user_time;
        info->total_system = task->total_system_time;

        if (ginfo) {
                ginfo->task_gpu_utilisation = task->task_gpu_ns;
        }

        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                uint64_t        tval;
                spl_t           x;

                if (thread->options & TH_OPT_IDLE_THREAD)
                        continue;

                x = splsched();
                thread_lock(thread);

                info->task_timer_wakeups_bin_1 += thread->thread_timer_wakeups_bin_1;
                info->task_timer_wakeups_bin_2 += thread->thread_timer_wakeups_bin_2;

                tval = timer_grab(&thread->user_timer);
                info->total_user += tval;

                tval = timer_grab(&thread->system_timer);
                if (thread->precise_user_kernel_time) {
                        info->total_system += tval;
                } else {
                        /* system_timer may represent either sys or user */
                        info->total_user += tval;
                }

                if (ginfo) {
                        ginfo->task_gpu_utilisation += ml_gpu_stat(thread);
                }
                thread_unlock(thread);
                splx(x);
        }
}

/* 
 *      task_gpu_utilisation
 *
 *      Returns the total gpu time used by the all the threads of the task
 *  (both dead and alive)
 */
uint64_t
task_gpu_utilisation(
        task_t  task)
{
        uint64_t gpu_time = 0;
        thread_t thread;

        task_lock(task);
        gpu_time += task->task_gpu_ns;

        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                spl_t x;
                x = splsched();
                thread_lock(thread);
                gpu_time += ml_gpu_stat(thread);
                thread_unlock(thread);
                splx(x);
        }

        task_unlock(task);
        return gpu_time;
}

kern_return_t
task_purgable_info(
        task_t                  task,
        task_purgable_info_t    *stats)
{
        if (task == TASK_NULL || stats == NULL)
                return KERN_INVALID_ARGUMENT;
        /* Take task reference */
        task_reference(task);
        vm_purgeable_stats((vm_purgeable_info_t)stats, task);
        /* Drop task reference */
        task_deallocate(task);
        return KERN_SUCCESS;
}

void
task_vtimer_set(
        task_t          task,
        integer_t       which)
{
        thread_t        thread;
        spl_t           x;

        /* assert(task == current_task()); */ /* bogus assert 4803227 4807483 */

        task_lock(task);

        task->vtimers |= which;

        switch (which) {

        case TASK_VTIMER_USER:
                queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        x = splsched();
                        thread_lock(thread);
                        if (thread->precise_user_kernel_time)
                                thread->vtimer_user_save = timer_grab(&thread->user_timer);
                        else
                                thread->vtimer_user_save = timer_grab(&thread->system_timer);
                        thread_unlock(thread);
                        splx(x);
                }
                break;

        case TASK_VTIMER_PROF:
                queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        x = splsched();
                        thread_lock(thread);
                        thread->vtimer_prof_save = timer_grab(&thread->user_timer);
                        thread->vtimer_prof_save += timer_grab(&thread->system_timer);
                        thread_unlock(thread);
                        splx(x);
                }
                break;

        case TASK_VTIMER_RLIM:
                queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        x = splsched();
                        thread_lock(thread);
                        thread->vtimer_rlim_save = timer_grab(&thread->user_timer);
                        thread->vtimer_rlim_save += timer_grab(&thread->system_timer);
                        thread_unlock(thread);
                        splx(x);
                }
                break;
        }

        task_unlock(task);
}

void
task_vtimer_clear(
        task_t          task,
        integer_t       which)
{
        assert(task == current_task());

        task_lock(task);

        task->vtimers &= ~which;

        task_unlock(task);
}

void
task_vtimer_update(
__unused
        task_t          task,
        integer_t       which,
        uint32_t        *microsecs)
{
        thread_t        thread = current_thread();
        uint32_t        tdelt;
        clock_sec_t     secs;
        uint64_t        tsum;

        assert(task == current_task());

        assert(task->vtimers & which);

        secs = tdelt = 0;

        switch (which) {

        case TASK_VTIMER_USER:
                if (thread->precise_user_kernel_time) {
                        tdelt = (uint32_t)timer_delta(&thread->user_timer,
                                                                &thread->vtimer_user_save);
                } else {
                        tdelt = (uint32_t)timer_delta(&thread->system_timer,
                                                                &thread->vtimer_user_save);
                }
                absolutetime_to_microtime(tdelt, &secs, microsecs);
                break;

        case TASK_VTIMER_PROF:
                tsum = timer_grab(&thread->user_timer);
                tsum += timer_grab(&thread->system_timer);
                tdelt = (uint32_t)(tsum - thread->vtimer_prof_save);
                absolutetime_to_microtime(tdelt, &secs, microsecs);
                /* if the time delta is smaller than a usec, ignore */
                if (*microsecs != 0)
                        thread->vtimer_prof_save = tsum;
                break;

        case TASK_VTIMER_RLIM:
                tsum = timer_grab(&thread->user_timer);
                tsum += timer_grab(&thread->system_timer);
                tdelt = (uint32_t)(tsum - thread->vtimer_rlim_save);
                thread->vtimer_rlim_save = tsum;
                absolutetime_to_microtime(tdelt, &secs, microsecs);
                break;
        }

}

/*
 *      task_assign:
 *
 *      Change the assigned processor set for the task
 */
kern_return_t
task_assign(
        __unused task_t         task,
        __unused processor_set_t        new_pset,
        __unused boolean_t      assign_threads)
{
        return(KERN_FAILURE);
}

/*
 *      task_assign_default:
 *
 *      Version of task_assign to assign to default processor set.
 */
kern_return_t
task_assign_default(
        task_t          task,
        boolean_t       assign_threads)
{
    return (task_assign(task, &pset0, assign_threads));
}

/*
 *      task_get_assignment
 *
 *      Return name of processor set that task is assigned to.
 */
kern_return_t
task_get_assignment(
        task_t          task,
        processor_set_t *pset)
{
        if (!task->active)
                return(KERN_FAILURE);

        *pset = &pset0;

        return (KERN_SUCCESS);
}

uint64_t
get_task_dispatchqueue_offset(
                task_t          task)
{
        return task->dispatchqueue_offset;
}

/*
 *      task_policy
 *
 *      Set scheduling policy and parameters, both base and limit, for
 *      the given task. Policy must be a policy which is enabled for the
 *      processor set. Change contained threads if requested. 
 */
kern_return_t
task_policy(
        __unused task_t                 task,
        __unused policy_t                       policy_id,
        __unused policy_base_t          base,
        __unused mach_msg_type_number_t count,
        __unused boolean_t                      set_limit,
        __unused boolean_t                      change)
{
        return(KERN_FAILURE);
}

/*
 *      task_set_policy
 *
 *      Set scheduling policy and parameters, both base and limit, for 
 *      the given task. Policy can be any policy implemented by the
 *      processor set, whether enabled or not. Change contained threads
 *      if requested.
 */
kern_return_t
task_set_policy(
        __unused task_t                 task,
        __unused processor_set_t                pset,
        __unused policy_t                       policy_id,
        __unused policy_base_t          base,
        __unused mach_msg_type_number_t base_count,
        __unused policy_limit_t         limit,
        __unused mach_msg_type_number_t limit_count,
        __unused boolean_t                      change)
{
        return(KERN_FAILURE);
}

kern_return_t
task_set_ras_pc(
        __unused task_t task,
        __unused vm_offset_t    pc,
        __unused vm_offset_t    endpc)
{
        return KERN_FAILURE;
}

void
task_synchronizer_destroy_all(task_t task)
{
        /*
         *  Destroy owned semaphores
         */
        semaphore_destroy_all(task);
}

/*
 * Install default (machine-dependent) initial thread state 
 * on the task.  Subsequent thread creation will have this initial
 * state set on the thread by machine_thread_inherit_taskwide().
 * Flavors and structures are exactly the same as those to thread_set_state()
 */
kern_return_t 
task_set_state(
        task_t task, 
        int flavor, 
        thread_state_t state, 
        mach_msg_type_number_t state_count)
{
        kern_return_t ret;

        if (task == TASK_NULL) {
                return (KERN_INVALID_ARGUMENT);
        }

        task_lock(task);

        if (!task->active) {
                task_unlock(task);
                return (KERN_FAILURE);
        }

        ret = machine_task_set_state(task, flavor, state, state_count);

        task_unlock(task);
        return ret;
}

/*
 * Examine the default (machine-dependent) initial thread state 
 * on the task, as set by task_set_state().  Flavors and structures
 * are exactly the same as those passed to thread_get_state().
 */
kern_return_t 
task_get_state(
        task_t  task, 
        int     flavor,
        thread_state_t state,
        mach_msg_type_number_t *state_count)
{
        kern_return_t ret;

        if (task == TASK_NULL) {
                return (KERN_INVALID_ARGUMENT);
        }

        task_lock(task);

        if (!task->active) {
                task_unlock(task);
                return (KERN_FAILURE);
        }

        ret = machine_task_get_state(task, flavor, state, state_count);

        task_unlock(task);
        return ret;
}

#if CONFIG_JETSAM
#define HWM_USERCORE_MINSPACE 250 // free space (in MB) required *after* core file creation

void __attribute__((noinline))
PROC_CROSSED_HIGH_WATERMARK__SEND_EXC_RESOURCE_AND_SUSPEND(int max_footprint_mb)
{
        task_t                                          task            = current_task();
        int                                                     pid         = 0;
        const char                                      *procname       = "unknown";
        mach_exception_data_type_t      code[EXCEPTION_CODE_MAX];

#ifdef MACH_BSD
        pid = proc_selfpid();

        if (pid == 1) {
                /*
                 * Cannot have ReportCrash analyzing
                 * a suspended initproc.
                 */
                return;
        }

        if (task->bsd_info != NULL)
                procname = proc_name_address(current_task()->bsd_info);
#endif

        if (hwm_user_cores) {
                int                             error;
                uint64_t                starttime, end;
                clock_sec_t             secs = 0;
                uint32_t                microsecs = 0;

                starttime = mach_absolute_time();
                /*
                 * Trigger a coredump of this process. Don't proceed unless we know we won't
                 * be filling up the disk; and ignore the core size resource limit for this
                 * core file.
                 */
                if ((error = coredump(current_task()->bsd_info, HWM_USERCORE_MINSPACE, COREDUMP_IGNORE_ULIMIT)) != 0) {
                        printf("couldn't take coredump of %s[%d]: %d\n", procname, pid, error);
                }
                /*
                * coredump() leaves the task suspended.
                */
                task_resume_internal(current_task());

                end = mach_absolute_time();
                absolutetime_to_microtime(end - starttime, &secs, &microsecs);
                printf("coredump of %s[%d] taken in %d secs %d microsecs\n",
                       proc_name_address(current_task()->bsd_info), pid, (int)secs, microsecs);
        }

        if (disable_exc_resource) {
                printf("process %s[%d] crossed memory high watermark (%d MB); EXC_RESOURCE "
                        "supressed by a boot-arg.\n", procname, pid, max_footprint_mb);
                return;
        }

        /*
         * A task that has triggered an EXC_RESOURCE, should not be
         * jetsammed when the device is under memory pressure.  Here
         * we set the P_MEMSTAT_TERMINATED flag so that the process
         * will be skipped if the memorystatus_thread wakes up.
         */
        proc_memstat_terminated(current_task()->bsd_info, TRUE);

        printf("process %s[%d] crossed memory high watermark (%d MB); sending "
                "EXC_RESOURCE.\n", procname, pid, max_footprint_mb);

        code[0] = code[1] = 0;
        EXC_RESOURCE_ENCODE_TYPE(code[0], RESOURCE_TYPE_MEMORY);
        EXC_RESOURCE_ENCODE_FLAVOR(code[0], FLAVOR_HIGH_WATERMARK);
        EXC_RESOURCE_HWM_ENCODE_LIMIT(code[0], max_footprint_mb);

        /*
         * Use the _internal_ variant so that no user-space
         * process can resume our task from under us.
         */
        task_suspend_internal(task);
        exception_triage(EXC_RESOURCE, code, EXCEPTION_CODE_MAX);
        task_resume_internal(task);

        /*
         * After the EXC_RESOURCE has been handled, we must clear the
         * P_MEMSTAT_TERMINATED flag so that the process can again be
         * considered for jetsam if the memorystatus_thread wakes up.
         */
        proc_memstat_terminated(current_task()->bsd_info, FALSE);  /* clear the flag */
}

/*
 * Callback invoked when a task exceeds its physical footprint limit.
 */
void
task_footprint_exceeded(int warning, __unused const void *param0, __unused const void *param1)
{
        ledger_amount_t max_footprint, max_footprint_mb;
        ledger_amount_t footprint_after_purge;
        task_t task;

        if (warning == LEDGER_WARNING_DIPPED_BELOW) {
                /*
                 * Task memory limits only provide a warning on the way up.
                 */
                return;
        }

        task = current_task();

        ledger_get_limit(task->ledger, task_ledgers.phys_footprint, &max_footprint);
        max_footprint_mb = max_footprint >> 20;

        /*
         * Try and purge all "volatile" memory in that task first.
         */
        (void) task_purge_volatile_memory(task);
        /* are we still over the limit ? */
        ledger_get_balance(task->ledger,
                           task_ledgers.phys_footprint,
                           &footprint_after_purge);
        if ((!warning &&
             footprint_after_purge <= max_footprint) ||
            (warning &&
             footprint_after_purge <= ((max_footprint *
                                        PHYS_FOOTPRINT_WARNING_LEVEL) / 100))) {
                /* all better now */
                ledger_reset_callback_state(task->ledger,
                                            task_ledgers.phys_footprint);
                return;
        }
        /* still over the limit after purging... */

        /*
         * If this an actual violation (not a warning),
         * generate a non-fatal high watermark EXC_RESOURCE.
         */
        if ((warning == 0) && (task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_PHYS_FOOTPRINT_EXCEPTION)) {
                PROC_CROSSED_HIGH_WATERMARK__SEND_EXC_RESOURCE_AND_SUSPEND((int)max_footprint_mb);
        }

        memorystatus_on_ledger_footprint_exceeded((warning == LEDGER_WARNING_ROSE_ABOVE) ? TRUE : FALSE,
                (int)max_footprint_mb);
}

extern int proc_check_footprint_priv(void);

kern_return_t
task_set_phys_footprint_limit(
        task_t task,
        int new_limit_mb,
        int *old_limit_mb)
{
        kern_return_t error;

        if ((error = proc_check_footprint_priv())) {
                return (KERN_NO_ACCESS);
        }

        return task_set_phys_footprint_limit_internal(task, new_limit_mb, old_limit_mb, FALSE);
}

kern_return_t
task_convert_phys_footprint_limit(
        int limit_mb,
        int *converted_limit_mb)
{
        if (limit_mb == -1) {
                /*
                 * No limit
                 */
                if (max_task_footprint != 0) {
                        *converted_limit_mb = (int)(max_task_footprint / 1024 / 1024);   /* bytes to MB */
                } else {
                        *converted_limit_mb = (int)(LEDGER_LIMIT_INFINITY >> 20);
                }
        } else {
                /* nothing to convert */
                *converted_limit_mb = limit_mb;
        }
        return (KERN_SUCCESS);
}


kern_return_t
task_set_phys_footprint_limit_internal(
        task_t task,
        int new_limit_mb,
        int *old_limit_mb,
        boolean_t trigger_exception)
{
        ledger_amount_t old;

        ledger_get_limit(task->ledger, task_ledgers.phys_footprint, &old);
        
        if (old_limit_mb) {
                /* 
                 * Check that limit >> 20 will not give an "unexpected" 32-bit
                 * result. There are, however, implicit assumptions that -1 mb limit
                 * equates to LEDGER_LIMIT_INFINITY.
                 */
                assert(((old & 0xFFF0000000000000LL) == 0) || (old == LEDGER_LIMIT_INFINITY));
                *old_limit_mb = (int)(old >> 20);
        }

        if (new_limit_mb == -1) {
                /*
                 * Caller wishes to remove the limit.
                 */
                ledger_set_limit(task->ledger, task_ledgers.phys_footprint,
                                 max_task_footprint ? max_task_footprint : LEDGER_LIMIT_INFINITY,
                                 max_task_footprint ? PHYS_FOOTPRINT_WARNING_LEVEL : 0);
                return (KERN_SUCCESS);
        }

#ifdef CONFIG_NOMONITORS
        return (KERN_SUCCESS);
#endif /* CONFIG_NOMONITORS */

        task_lock(task);

        if (trigger_exception) {
                task->rusage_cpu_flags |= TASK_RUSECPU_FLAGS_PHYS_FOOTPRINT_EXCEPTION;
        } else {
                task->rusage_cpu_flags &= ~TASK_RUSECPU_FLAGS_PHYS_FOOTPRINT_EXCEPTION;
        }

        ledger_set_limit(task->ledger, task_ledgers.phys_footprint,
                (ledger_amount_t)new_limit_mb << 20, PHYS_FOOTPRINT_WARNING_LEVEL);

        if (task == current_task()) {
                ledger_check_new_balance(task->ledger, task_ledgers.phys_footprint);
        }

        task_unlock(task);

        return (KERN_SUCCESS);
}

kern_return_t
task_get_phys_footprint_limit(          
        task_t task,
        int *limit_mb)
{
        ledger_amount_t limit;
    
        ledger_get_limit(task->ledger, task_ledgers.phys_footprint, &limit);
        /* 
         * Check that limit >> 20 will not give an "unexpected" signed, 32-bit
         * result. There are, however, implicit assumptions that -1 mb limit
         * equates to LEDGER_LIMIT_INFINITY.
         */
        assert(((limit & 0xFFF0000000000000LL) == 0) || (limit == LEDGER_LIMIT_INFINITY));
        *limit_mb = (int)(limit >> 20);
        
        return (KERN_SUCCESS);
}
#else /* CONFIG_JETSAM */
kern_return_t
task_set_phys_footprint_limit(
        __unused task_t task,
        __unused int new_limit_mb,
        __unused int *old_limit_mb)
{
        return (KERN_FAILURE);
}

kern_return_t
task_get_phys_footprint_limit(          
        __unused task_t task,
        __unused int *limit_mb)
{
        return (KERN_FAILURE);
}
#endif /* CONFIG_JETSAM */

/*
 * We need to export some functions to other components that
 * are currently implemented in macros within the osfmk
 * component.  Just export them as functions of the same name.
 */
boolean_t is_kerneltask(task_t t)
{
        if (t == kernel_task)
                return (TRUE);

        return (FALSE);
}

int
check_for_tasksuspend(task_t task)
{

        if (task == TASK_NULL)
                return (0);

        return (task->suspend_count > 0);
}

#undef current_task
task_t current_task(void);
task_t current_task(void)
{
        return (current_task_fast());
}

#undef task_reference
void task_reference(task_t task);
void
task_reference(
        task_t          task)
{
        if (task != TASK_NULL)
                task_reference_internal(task);
}

/* defined in bsd/kern/kern_prot.c */
extern int get_audit_token_pid(audit_token_t *audit_token);

int task_pid(task_t task)
{
        if (task)
                return get_audit_token_pid(&task->audit_token);
        return -1;
}


/* 
 * This routine is called always with task lock held.
 * And it returns a thread handle without reference as the caller
 * operates on it under the task lock held.
 */
thread_t
task_findtid(task_t task, uint64_t tid)
{
        thread_t thread= THREAD_NULL;

        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        if (thread->thread_id == tid)
                                return(thread);
        }
        return(THREAD_NULL);
}

/*
 * Control the CPU usage monitor for a task.
 */
kern_return_t
task_cpu_usage_monitor_ctl(task_t task, uint32_t *flags)
{
        int error = KERN_SUCCESS;

        if (*flags & CPUMON_MAKE_FATAL) {
                task->rusage_cpu_flags |= TASK_RUSECPU_FLAGS_FATAL_CPUMON;
        } else {
                error = KERN_INVALID_ARGUMENT;
        }

        return error;
}

/*
 * Control the wakeups monitor for a task.
 */
kern_return_t
task_wakeups_monitor_ctl(task_t task, uint32_t *flags, int32_t *rate_hz)
{
        ledger_t ledger = task->ledger;

        task_lock(task);
        if (*flags & WAKEMON_GET_PARAMS) {
                ledger_amount_t limit;
                uint64_t                period;

                ledger_get_limit(ledger, task_ledgers.interrupt_wakeups, &limit);
                ledger_get_period(ledger, task_ledgers.interrupt_wakeups, &period);

                if (limit != LEDGER_LIMIT_INFINITY) {
                        /*
                         * An active limit means the wakeups monitor is enabled.
                         */
                        *rate_hz = (int32_t)(limit / (int64_t)(period / NSEC_PER_SEC));
                        *flags = WAKEMON_ENABLE;
                        if (task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_FATAL_WAKEUPSMON) {
                                *flags |= WAKEMON_MAKE_FATAL;
                        }
                } else {
                        *flags = WAKEMON_DISABLE;
                        *rate_hz = -1;
                }

                /*
                 * If WAKEMON_GET_PARAMS is present in flags, all other flags are ignored.
                 */
                task_unlock(task);
                return KERN_SUCCESS;
        }

        if (*flags & WAKEMON_ENABLE) {
                if (*flags & WAKEMON_SET_DEFAULTS) {
                        *rate_hz = task_wakeups_monitor_rate;
                }

#ifndef CONFIG_NOMONITORS
                if (*flags & WAKEMON_MAKE_FATAL) {
                        task->rusage_cpu_flags |= TASK_RUSECPU_FLAGS_FATAL_WAKEUPSMON;
                }
#endif /* CONFIG_NOMONITORS */

                if (*rate_hz < 0) {
                        task_unlock(task);
                        return KERN_INVALID_ARGUMENT;
                }

#ifndef CONFIG_NOMONITORS
                ledger_set_limit(ledger, task_ledgers.interrupt_wakeups, *rate_hz * task_wakeups_monitor_interval,
                        task_wakeups_monitor_ustackshots_trigger_pct);
                ledger_set_period(ledger, task_ledgers.interrupt_wakeups, task_wakeups_monitor_interval * NSEC_PER_SEC);
                ledger_enable_callback(ledger, task_ledgers.interrupt_wakeups);
#endif /* CONFIG_NOMONITORS */
        } else if (*flags & WAKEMON_DISABLE) {
                /*
                 * Caller wishes to disable wakeups monitor on the task.
                 *
                 * Disable telemetry if it was triggered by the wakeups monitor, and
                 * remove the limit & callback on the wakeups ledger entry.
                 */
#if CONFIG_TELEMETRY
                telemetry_task_ctl_locked(task, TF_WAKEMON_WARNING, 0);
#endif
                ledger_disable_refill(ledger, task_ledgers.interrupt_wakeups);
                ledger_disable_callback(ledger, task_ledgers.interrupt_wakeups);
        }

        task_unlock(task);
        return KERN_SUCCESS;
}

void
task_wakeups_rate_exceeded(int warning, __unused const void *param0, __unused const void *param1)
{
        if (warning == LEDGER_WARNING_ROSE_ABOVE) {
#if CONFIG_TELEMETRY            
                /*
                 * This task is in danger of violating the wakeups monitor. Enable telemetry on this task
                 * so there are micro-stackshots available if and when EXC_RESOURCE is triggered.
                 */
                telemetry_task_ctl(current_task(), TF_WAKEMON_WARNING, 1);
#endif
                return;
        }

#if CONFIG_TELEMETRY
        /*
         * If the balance has dipped below the warning level (LEDGER_WARNING_DIPPED_BELOW) or
         * exceeded the limit, turn telemetry off for the task.
         */
        telemetry_task_ctl(current_task(), TF_WAKEMON_WARNING, 0);
#endif

        if (warning == 0) {
                THIS_PROCESS_IS_CAUSING_TOO_MANY_WAKEUPS__SENDING_EXC_RESOURCE();
        }
}

void __attribute__((noinline))
THIS_PROCESS_IS_CAUSING_TOO_MANY_WAKEUPS__SENDING_EXC_RESOURCE(void)
{
        task_t                                          task            = current_task();
        int                                                     pid         = 0;
        const char                                      *procname       = "unknown";
        uint64_t                                        observed_wakeups_rate;
        uint64_t                                        permitted_wakeups_rate;
        uint64_t                                        observation_interval;
        mach_exception_data_type_t      code[EXCEPTION_CODE_MAX];
        struct ledger_entry_info        lei;

#ifdef MACH_BSD
        pid = proc_selfpid();
        if (task->bsd_info != NULL)
                procname = proc_name_address(current_task()->bsd_info);
#endif

        ledger_get_entry_info(task->ledger, task_ledgers.interrupt_wakeups, &lei);

        /*
         * Disable the exception notification so we don't overwhelm
         * the listener with an endless stream of redundant exceptions.
         */
        uint32_t flags = WAKEMON_DISABLE;
        task_wakeups_monitor_ctl(task, &flags, NULL);

        observed_wakeups_rate = (lei.lei_balance * (int64_t)NSEC_PER_SEC) / lei.lei_last_refill;
        permitted_wakeups_rate = lei.lei_limit / task_wakeups_monitor_interval;
        observation_interval = lei.lei_refill_period / NSEC_PER_SEC;

        if (disable_exc_resource) {
                printf("process %s[%d] caught causing excessive wakeups. EXC_RESOURCE "
                        "supressed by a boot-arg\n", procname, pid);
                return;
        }
        if (audio_active) {
                printf("process %s[%d] caught causing excessive wakeups. EXC_RESOURCE "
                       "supressed due to audio playback\n", procname, pid);
                return;
        }
        printf("process %s[%d] caught causing excessive wakeups. Observed wakeups rate "
                "(per sec): %lld; Maximum permitted wakeups rate (per sec): %lld; Observation "
                "period: %lld seconds; Task lifetime number of wakeups: %lld\n",
                procname, pid, observed_wakeups_rate, permitted_wakeups_rate,
                observation_interval, lei.lei_credit);

        code[0] = code[1] = 0;
        EXC_RESOURCE_ENCODE_TYPE(code[0], RESOURCE_TYPE_WAKEUPS);
        EXC_RESOURCE_ENCODE_FLAVOR(code[0], FLAVOR_WAKEUPS_MONITOR);
        EXC_RESOURCE_CPUMONITOR_ENCODE_WAKEUPS_PERMITTED(code[0], task_wakeups_monitor_rate);
        EXC_RESOURCE_CPUMONITOR_ENCODE_OBSERVATION_INTERVAL(code[0], observation_interval);
        EXC_RESOURCE_CPUMONITOR_ENCODE_WAKEUPS_OBSERVED(code[1], lei.lei_balance * (int64_t)NSEC_PER_SEC / lei.lei_last_refill);        
        exception_triage(EXC_RESOURCE, code, EXCEPTION_CODE_MAX);

        if (task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_FATAL_WAKEUPSMON) {
                task_terminate_internal(task);
        }
}

kern_return_t
task_purge_volatile_memory(
        task_t  task)
{
        vm_map_t        map;
        int             num_object_purged;

        if (task == TASK_NULL)
                return KERN_INVALID_TASK;

        task_lock(task);

        if (!task->active) {
                task_unlock(task);
                return KERN_INVALID_TASK;
        }
        map = task->map;
        if (map == VM_MAP_NULL) {
                task_unlock(task);
                return KERN_INVALID_TASK;
        }
        vm_map_reference(task->map);

        task_unlock(task);

        num_object_purged = vm_map_purge(map);
        vm_map_deallocate(map);

        return KERN_SUCCESS;
}

/* Placeholders for the task set/get voucher interfaces */
kern_return_t 
task_get_mach_voucher(
        task_t                  task,
        mach_voucher_selector_t __unused which,
        ipc_voucher_t           *voucher)
{
        if (TASK_NULL == task)
                return KERN_INVALID_TASK;

        *voucher = NULL;
        return KERN_SUCCESS;
}

kern_return_t 
task_set_mach_voucher(
        task_t                  task,
        ipc_voucher_t           __unused voucher)
{
        if (TASK_NULL == task)
                return KERN_INVALID_TASK;

        return KERN_SUCCESS;
}

kern_return_t
task_swap_mach_voucher(
        task_t                  task,
        ipc_voucher_t           new_voucher,
        ipc_voucher_t           *in_out_old_voucher)
{
        if (TASK_NULL == task)
                return KERN_INVALID_TASK;

        *in_out_old_voucher = new_voucher;
        return KERN_SUCCESS;
}

void task_set_gpu_denied(task_t task, boolean_t denied)
{
        task_lock(task);

        if (denied) {
                task->t_flags |= TF_GPU_DENIED;
        } else {
                task->t_flags &= ~TF_GPU_DENIED;
        }

        task_unlock(task);
}

boolean_t task_is_gpu_denied(task_t task)
{
        /* We don't need the lock to read this flag */
        return (task->t_flags & TF_GPU_DENIED) ? TRUE : FALSE;
}

void task_update_logical_writes(task_t task, uint32_t io_size, int flags)
{
        KERNEL_DEBUG_CONSTANT((MACHDBG_CODE(DBG_MACH_VM, VM_DATA_WRITE)) | DBG_FUNC_NONE, task_pid(task), io_size, flags, 0, 0);
        switch(flags) {
                case TASK_WRITE_IMMEDIATE:
                        OSAddAtomic64(io_size, (SInt64 *)&(task->task_immediate_writes));
                        break;
                case TASK_WRITE_DEFERRED:
                        OSAddAtomic64(io_size, (SInt64 *)&(task->task_deferred_writes));
                        break;
                case TASK_WRITE_INVALIDATED:
                        OSAddAtomic64(io_size, (SInt64 *)&(task->task_invalidated_writes));
                        break;
                case TASK_WRITE_METADATA:
                        OSAddAtomic64(io_size, (SInt64 *)&(task->task_metadata_writes));
                        break;
        }
        return;
}