]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/kern_resource.c
xnu-7195.101.1.tar.gz
[apple/xnu.git] / bsd / kern / kern_resource.c
index d2473dbf0476c2d54e303c72d01cfc0a4ae6526f..65c6d020ccb15afd8532fc69588f3c865b2a70c8 100644 (file)
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2020 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
  * 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,
@@ -22,7 +22,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
@@ -81,8 +81,6 @@
 #include <sys/malloc.h>
 #include <sys/proc_internal.h>
 #include <sys/kauth.h>
-#include <machine/spl.h>
-
 #include <sys/mount_internal.h>
 #include <sys/sysproto.h>
 
 #include <mach/vm_map.h>
 #include <mach/mach_vm.h>
 #include <mach/thread_act.h>  /* for thread_policy_set( ) */
-#include <kern/lock.h>
 #include <kern/thread.h>
+#include <kern/policy_internal.h>
 
 #include <kern/task.h>
-#include <kern/clock.h>                /* for absolutetime_to_microtime() */
-#include <netinet/in.h>                /* for TRAFFIC_MGT_SO_* */
-#include <sys/socketvar.h>     /* for struct socket */
+#include <kern/clock.h>         /* for absolutetime_to_microtime() */
+#include <netinet/in.h>         /* for TRAFFIC_MGT_SO_* */
+#include <sys/socketvar.h>      /* for struct socket */
+#if NECP
+#include <net/necp.h>
+#endif /* NECP */
 
 #include <vm/vm_map.h>
 
-int    donice(struct proc *curp, struct proc *chgp, int n);
-int    dosetrlimit(struct proc *p, u_int which, struct rlimit *limp);
-int    uthread_get_background_state(uthread_t);
-static void do_background_socket(struct proc *p, thread_t thread, int priority);
-static int do_background_thread(struct proc *curp, thread_t thread, int priority);
+#include <kern/assert.h>
+#include <sys/resource.h>
+#include <sys/priv.h>
+#include <IOKit/IOBSD.h>
+
+#if CONFIG_MACF
+#include <security/mac_framework.h>
+#endif
+
+int     donice(struct proc *curp, struct proc *chgp, int n);
+int     dosetrlimit(struct proc *p, u_int which, struct rlimit *limp);
+int     uthread_get_background_state(uthread_t);
+static void do_background_socket(struct proc *p, thread_t thread);
+static int do_background_thread(thread_t thread, int priority);
 static int do_background_proc(struct proc *curp, struct proc *targetp, int priority);
-void proc_apply_task_networkbg_internal(proc_t);
+static int set_gpudeny_proc(struct proc *curp, struct proc *targetp, int priority);
+static int proc_set_darwin_role(proc_t curp, proc_t targetp, int priority);
+static int proc_get_darwin_role(proc_t curp, proc_t targetp, int *priority);
+static int get_background_proc(struct proc *curp, struct proc *targetp, int *priority);
+int proc_pid_rusage(int pid, int flavor, user_addr_t buf, int32_t *retval);
+void gather_rusage_info(proc_t p, rusage_info_current *ru, int flavor);
+int fill_task_rusage(task_t task, rusage_info_current *ri);
+void fill_task_billed_usage(task_t task, rusage_info_current *ri);
+int fill_task_io_rusage(task_t task, rusage_info_current *ri);
+int fill_task_qos_rusage(task_t task, rusage_info_current *ri);
+uint64_t get_task_logical_writes(task_t task, boolean_t external);
+void fill_task_monotonic_rusage(task_t task, rusage_info_current *ri);
+
+int proc_get_rusage(proc_t p, int flavor, user_addr_t buffer, __unused int is_zombie);
+
+rlim_t maxdmap = MAXDSIZ;       /* XXX */
+rlim_t maxsmap = MAXSSIZ - PAGE_MAX_SIZE;       /* XXX */
+
+/* For plimit reference count */
+os_refgrp_decl(, rlimit_refgrp, "plimit_refcnt", NULL);
 
-rlim_t maxdmap = MAXDSIZ;      /* XXX */ 
-rlim_t maxsmap = MAXSSIZ - PAGE_SIZE;  /* XXX */ 
+ZONE_DECLARE(plimit_zone, "plimit", sizeof(struct plimit), ZC_NOENCRYPT);
 
 /*
  * Limits on the number of open files per process, and the number
@@ -124,21 +152,21 @@ rlim_t maxsmap = MAXSSIZ - PAGE_SIZE;     /* XXX */
  *
  * Note: would be in kern/subr_param.c in FreeBSD.
  */
-__private_extern__ int maxfilesperproc = OPEN_MAX;             /* per-proc open files limit */
+__private_extern__ int maxfilesperproc = OPEN_MAX;              /* per-proc open files limit */
 
 SYSCTL_INT(_kern, KERN_MAXPROCPERUID, maxprocperuid, CTLFLAG_RW | CTLFLAG_LOCKED,
-               &maxprocperuid, 0, "Maximum processes allowed per userid" );
+    &maxprocperuid, 0, "Maximum processes allowed per userid" );
 
 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW | CTLFLAG_LOCKED,
-               &maxfilesperproc, 0, "Maximum files allowed open per process" );
+    &maxfilesperproc, 0, "Maximum files allowed open per process" );
 
 /* Args and fn for proc_iteration callback used in setpriority */
 struct puser_nice_args {
        proc_t curp;
-       int     prio;
-       id_t    who;
-       int *   foundp;
-       int *   errorp;
+       int     prio;
+       id_t    who;
+       int *   foundp;
+       int *   errorp;
 };
 static int puser_donice_callback(proc_t p, void * arg);
 
@@ -146,9 +174,9 @@ static int puser_donice_callback(proc_t p, void * arg);
 /* Args and fn for proc_iteration callback used in setpriority */
 struct ppgrp_nice_args {
        proc_t curp;
-       int     prio;
-       int *   foundp;
-       int *   errorp;
+       int     prio;
+       int *   foundp;
+       int *   errorp;
 };
 static int ppgrp_donice_callback(proc_t p, void * arg);
 
@@ -161,24 +189,26 @@ getpriority(struct proc *curp, struct getpriority_args *uap, int32_t *retval)
        struct proc *p;
        int low = PRIO_MAX + 1;
        kauth_cred_t my_cred;
+       int refheld = 0;
+       int error = 0;
 
        /* would also test (uap->who < 0), but id_t is unsigned */
-       if (uap->who > 0x7fffffff)
-               return (EINVAL);
+       if (uap->who > 0x7fffffff) {
+               return EINVAL;
+       }
 
        switch (uap->which) {
-
        case PRIO_PROCESS:
                if (uap->who == 0) {
                        p = curp;
                        low = p->p_nice;
                } else {
                        p = proc_find(uap->who);
-                       if (p == 0)
+                       if (p == 0) {
                                break;
+                       }
                        low = p->p_nice;
                        proc_rele(p);
-
                }
                break;
 
@@ -188,14 +218,15 @@ getpriority(struct proc *curp, struct getpriority_args *uap, int32_t *retval)
                if (uap->who == 0) {
                        /* returns the pgrp to ref */
                        pg = proc_pgrp(curp);
-                } else if ((pg = pgfind(uap->who)) == PGRP_NULL) {
+               } else if ((pg = pgfind(uap->who)) == PGRP_NULL) {
                        break;
                }
                /* No need for iteration as it is a simple scan */
                pgrp_lock(pg);
-               for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) {
-                       if (p->p_nice < low)
+               PGMEMBERS_FOREACH(pg, p) {
+                       if (p->p_nice < low) {
                                low = p->p_nice;
+                       }
                }
                pgrp_unlock(pg);
                pg_rele(pg);
@@ -203,16 +234,18 @@ getpriority(struct proc *curp, struct getpriority_args *uap, int32_t *retval)
        }
 
        case PRIO_USER:
-               if (uap->who == 0)
+               if (uap->who == 0) {
                        uap->who = kauth_cred_getuid(kauth_cred_get());
+               }
 
                proc_list_lock();
 
                for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
                        my_cred = kauth_cred_proc_ref(p);
                        if (kauth_cred_getuid(my_cred) == uap->who &&
-                           p->p_nice < low)
+                           p->p_nice < low) {
                                low = p->p_nice;
+                       }
                        kauth_cred_unref(&my_cred);
                }
 
@@ -220,32 +253,66 @@ getpriority(struct proc *curp, struct getpriority_args *uap, int32_t *retval)
 
                break;
 
-       case PRIO_DARWIN_THREAD: {
-               thread_t                        thread;
-               struct uthread          *ut;
-
+       case PRIO_DARWIN_THREAD:
                /* we currently only support the current thread */
                if (uap->who != 0) {
-                       return (EINVAL);
+                       return EINVAL;
+               }
+
+               low = proc_get_thread_policy(current_thread(), TASK_POLICY_INTERNAL, TASK_POLICY_DARWIN_BG);
+
+               break;
+
+       case PRIO_DARWIN_PROCESS:
+               if (uap->who == 0) {
+                       p = curp;
+               } else {
+                       p = proc_find(uap->who);
+                       if (p == PROC_NULL) {
+                               break;
+                       }
+                       refheld = 1;
                }
-       
-               thread = current_thread();
-               ut = get_bsdthread_info(thread);
 
-               low = 0;
-               if ( (ut->uu_flag & UT_BACKGROUND_TRAFFIC_MGT) != 0 ) {
-                       low = 1;
+               error = get_background_proc(curp, p, &low);
+
+               if (refheld) {
+                       proc_rele(p);
+               }
+               if (error) {
+                       return error;
+               }
+               break;
+
+       case PRIO_DARWIN_ROLE:
+               if (uap->who == 0) {
+                       p = curp;
+               } else {
+                       p = proc_find(uap->who);
+                       if (p == PROC_NULL) {
+                               break;
+                       }
+                       refheld = 1;
+               }
+
+               error = proc_get_darwin_role(curp, p, &low);
+
+               if (refheld) {
+                       proc_rele(p);
+               }
+               if (error) {
+                       return error;
                }
                break;
-       }
 
        default:
-               return (EINVAL);
+               return EINVAL;
+       }
+       if (low == PRIO_MAX + 1) {
+               return ESRCH;
        }
-       if (low == PRIO_MAX + 1)
-               return (ESRCH);
        *retval = low;
-       return (0);
+       return 0;
 }
 
 /* call back function used for proc iteration in PRIO_USER */
@@ -259,16 +326,17 @@ puser_donice_callback(proc_t p, void * arg)
        my_cred = kauth_cred_proc_ref(p);
        if (kauth_cred_getuid(my_cred) == pun->who) {
                error = donice(pun->curp, p, pun->prio);
-               if (pun->errorp != NULL)
+               if (pun->errorp != NULL) {
                        *pun->errorp = error;
+               }
                if (pun->foundp != NULL) {
                        n = *pun->foundp;
-                       *pun->foundp = n+1;
+                       *pun->foundp = n + 1;
                }
        }
        kauth_cred_unref(&my_cred);
 
-       return(PROC_RETURNED);
+       return PROC_RETURNED;
 }
 
 /* call back function used for proc iteration in PRIO_PGRP */
@@ -280,14 +348,15 @@ ppgrp_donice_callback(proc_t p, void * arg)
        int n;
 
        error = donice(pun->curp, p, pun->prio);
-       if (pun->errorp != NULL)
+       if (pun->errorp != NULL) {
                *pun->errorp = error;
-       if (pun->foundp!= NULL) {
+       }
+       if (pun->foundp != NULL) {
                n = *pun->foundp;
-               *pun->foundp = n+1;
+               *pun->foundp = n + 1;
        }
 
-       return(PROC_RETURNED);
+       return PROC_RETURNED;
 }
 
 /*
@@ -299,7 +368,7 @@ ppgrp_donice_callback(proc_t p, void * arg)
  */
 /* ARGSUSED */
 int
-setpriority(struct proc *curp, struct setpriority_args *uap, __unused int32_t *retval)
+setpriority(struct proc *curp, struct setpriority_args *uap, int32_t *retval)
 {
        struct proc *p;
        int found = 0, error = 0;
@@ -310,40 +379,43 @@ setpriority(struct proc *curp, struct setpriority_args *uap, __unused int32_t *r
        AUDIT_ARG(value32, uap->prio);
 
        /* would also test (uap->who < 0), but id_t is unsigned */
-       if (uap->who > 0x7fffffff)
-               return (EINVAL);
+       if (uap->who > 0x7fffffff) {
+               return EINVAL;
+       }
 
        switch (uap->which) {
-
        case PRIO_PROCESS:
-               if (uap->who == 0)
+               if (uap->who == 0) {
                        p = curp;
-               else {
+               else {
                        p = proc_find(uap->who);
-                       if (p == 0)
+                       if (p == 0) {
                                break;
+                       }
                        refheld = 1;
                }
                error = donice(curp, p, uap->prio);
                found++;
-               if (refheld != 0)
+               if (refheld != 0) {
                        proc_rele(p);
+               }
                break;
 
        case PRIO_PGRP: {
                struct pgrp *pg = PGRP_NULL;
                struct ppgrp_nice_args ppgrp;
-                
+
                if (uap->who == 0) {
                        pg = proc_pgrp(curp);
-                } else if ((pg = pgfind(uap->who)) == PGRP_NULL)
+               } else if ((pg = pgfind(uap->who)) == PGRP_NULL) {
                        break;
+               }
 
                ppgrp.curp = curp;
                ppgrp.prio = uap->prio;
                ppgrp.foundp = &found;
                ppgrp.errorp = &error;
-               
+
                /* PGRP_DROPREF drops the reference on process group */
                pgrp_iterate(pg, PGRP_DROPREF, ppgrp_donice_callback, (void *)&ppgrp, NULL, NULL);
 
@@ -353,8 +425,9 @@ setpriority(struct proc *curp, struct setpriority_args *uap, __unused int32_t *r
        case PRIO_USER: {
                struct puser_nice_args punice;
 
-               if (uap->who == 0)
+               if (uap->who == 0) {
                        uap->who = kauth_cred_getuid(kauth_cred_get());
+               }
 
                punice.curp = curp;
                punice.prio = uap->prio;
@@ -370,43 +443,82 @@ setpriority(struct proc *curp, struct setpriority_args *uap, __unused int32_t *r
        case PRIO_DARWIN_THREAD: {
                /* we currently only support the current thread */
                if (uap->who != 0) {
-                       return (EINVAL);
-               }
-               error = do_background_thread(curp, current_thread(), uap->prio);
-               if (!error) {
-                       (void) do_background_socket(curp, current_thread(), uap->prio);
+                       return EINVAL;
                }
+
+               error = do_background_thread(current_thread(), uap->prio);
                found++;
                break;
        }
 
        case PRIO_DARWIN_PROCESS: {
-               if (uap->who == 0)
+               if (uap->who == 0) {
                        p = curp;
-               else {
+               else {
                        p = proc_find(uap->who);
-                       if (p == 0)
+                       if (p == 0) {
                                break;
+                       }
                        refheld = 1;
                }
 
                error = do_background_proc(curp, p, uap->prio);
-               if (!error) {
-                       (void) do_background_socket(p, NULL, uap->prio);
+
+               found++;
+               if (refheld != 0) {
+                       proc_rele(p);
+               }
+               break;
+       }
+
+       case PRIO_DARWIN_GPU: {
+               if (uap->who == 0) {
+                       return EINVAL;
+               }
+
+               p = proc_find(uap->who);
+               if (p == PROC_NULL) {
+                       break;
+               }
+
+               error = set_gpudeny_proc(curp, p, uap->prio);
+
+               found++;
+               proc_rele(p);
+               break;
+       }
+
+       case PRIO_DARWIN_ROLE: {
+               if (uap->who == 0) {
+                       p = curp;
+               } else {
+                       p = proc_find(uap->who);
+                       if (p == PROC_NULL) {
+                               break;
+                       }
+                       refheld = 1;
                }
-               
+
+               error = proc_set_darwin_role(curp, p, uap->prio);
+
                found++;
-               if (refheld != 0)
+               if (refheld != 0) {
                        proc_rele(p);
+               }
                break;
        }
 
        default:
-               return (EINVAL);
+               return EINVAL;
+       }
+       if (found == 0) {
+               return ESRCH;
+       }
+       if (error == EIDRM) {
+               *retval = -2;
+               error = 0;
        }
-       if (found == 0)
-               return (ESRCH);
-       return (error);
+       return error;
 }
 
 
@@ -432,324 +544,367 @@ donice(struct proc *curp, struct proc *chgp, int n)
                error = EPERM;
                goto out;
        }
-       if (n > PRIO_MAX)
+       if (n > PRIO_MAX) {
                n = PRIO_MAX;
-       if (n < PRIO_MIN)
+       }
+       if (n < PRIO_MIN) {
                n = PRIO_MIN;
+       }
        if (n < chgp->p_nice && suser(ucred, &curp->p_acflag)) {
                error = EACCES;
                goto out;
        }
 #if CONFIG_MACF
        error = mac_proc_check_sched(curp, chgp);
-       if (error) 
+       if (error) {
                goto out;
+       }
 #endif
        proc_lock(chgp);
-       chgp->p_nice = n;
+       chgp->p_nice = (char)n;
        proc_unlock(chgp);
        (void)resetpriority(chgp);
 out:
        kauth_cred_unref(&ucred);
        kauth_cred_unref(&my_cred);
-       return (error);
+       return error;
 }
 
 static int
-do_background_proc(struct proc *curp, struct proc *targetp, int priority)
+set_gpudeny_proc(struct proc *curp, struct proc *targetp, int priority)
 {
        int error = 0;
        kauth_cred_t ucred;
        kauth_cred_t target_cred;
-#if CONFIG_EMBEDDED
-       task_category_policy_data_t info;
-#endif
 
        ucred = kauth_cred_get();
        target_cred = kauth_cred_proc_ref(targetp);
 
+       /* TODO: Entitlement instead of uid check */
+
        if (!kauth_cred_issuser(ucred) && kauth_cred_getruid(ucred) &&
            kauth_cred_getuid(ucred) != kauth_cred_getuid(target_cred) &&
-           kauth_cred_getruid(ucred) != kauth_cred_getuid(target_cred))
-       {
+           kauth_cred_getruid(ucred) != kauth_cred_getuid(target_cred)) {
+               error = EPERM;
+               goto out;
+       }
+
+       if (curp == targetp) {
                error = EPERM;
                goto out;
        }
 
 #if CONFIG_MACF
        error = mac_proc_check_sched(curp, targetp);
-       if (error) 
+       if (error) {
                goto out;
+       }
 #endif
 
-#if !CONFIG_EMBEDDED
-       if (priority == PRIO_DARWIN_NONUI)
-               error = proc_apply_task_gpuacc(targetp->task, TASK_POLICY_HWACCESS_GPU_ATTRIBUTE_NOACCESS);
-       else
-               error = proc_set1_bgtaskpolicy(targetp->task, priority);
-       if (error)
+       switch (priority) {
+       case PRIO_DARWIN_GPU_DENY:
+               task_set_gpu_denied(proc_task(targetp), TRUE);
+               break;
+       case PRIO_DARWIN_GPU_ALLOW:
+               task_set_gpu_denied(proc_task(targetp), FALSE);
+               break;
+       default:
+               error = EINVAL;
                goto out;
-#else /* !CONFIG_EMBEDDED */
-
-       /* set the max scheduling priority on the task */
-       if (priority == PRIO_DARWIN_BG) { 
-               info.role = TASK_THROTTLE_APPLICATION;
        }
-       else if (priority == PRIO_DARWIN_NONUI) { 
-               info.role = TASK_NONUI_APPLICATION;
-       }
-       else {
-               info.role = TASK_DEFAULT_APPLICATION;
+
+out:
+       kauth_cred_unref(&target_cred);
+       return error;
+}
+
+static int
+proc_set_darwin_role(proc_t curp, proc_t targetp, int priority)
+{
+       int error = 0;
+       uint32_t flagsp = 0;
+
+       kauth_cred_t ucred, target_cred;
+
+       ucred = kauth_cred_get();
+       target_cred = kauth_cred_proc_ref(targetp);
+
+       if (!kauth_cred_issuser(ucred) && kauth_cred_getruid(ucred) &&
+           kauth_cred_getuid(ucred) != kauth_cred_getuid(target_cred) &&
+           kauth_cred_getruid(ucred) != kauth_cred_getuid(target_cred)) {
+               if (priv_check_cred(ucred, PRIV_SETPRIORITY_DARWIN_ROLE, 0) != 0) {
+                       error = EPERM;
+                       goto out;
+               }
        }
 
-       error = task_policy_set(targetp->task,
-                       TASK_CATEGORY_POLICY,
-                       (task_policy_t) &info,
-                       TASK_CATEGORY_POLICY_COUNT);
+       if (curp != targetp) {
+#if CONFIG_MACF
+               if ((error = mac_proc_check_sched(curp, targetp))) {
+                       goto out;
+               }
+#endif
+       }
 
-       if (error)
+       proc_get_darwinbgstate(proc_task(targetp), &flagsp);
+       if ((flagsp & PROC_FLAG_APPLICATION) != PROC_FLAG_APPLICATION) {
+               error = ENOTSUP;
                goto out;
+       }
 
-       proc_lock(targetp);
+       task_role_t role = TASK_UNSPECIFIED;
 
-       /* mark proc structure as backgrounded */
-       if (priority == PRIO_DARWIN_BG) {
-               targetp->p_lflag |= P_LBACKGROUND;
-       } else {
-               targetp->p_lflag &= ~P_LBACKGROUND;
+       if ((error = proc_darwin_role_to_task_role(priority, &role))) {
+               goto out;
        }
 
-       /* set or reset the disk I/O priority */
-       targetp->p_iopol_disk = (priority == PRIO_DARWIN_BG ? 
-                       IOPOL_THROTTLE : IOPOL_DEFAULT); 
-
-       proc_unlock(targetp);
-#endif /* !CONFIG_EMBEDDED */
+       proc_set_task_policy(proc_task(targetp), TASK_POLICY_ATTRIBUTE,
+           TASK_POLICY_ROLE, role);
 
 out:
        kauth_cred_unref(&target_cred);
-       return (error);
+       return error;
 }
 
-static void 
-do_background_socket(struct proc *p, thread_t thread, int priority)
+static int
+proc_get_darwin_role(proc_t curp, proc_t targetp, int *priority)
 {
-       struct filedesc                     *fdp;
-       struct fileproc                     *fp;
-       int                                 i;
-
-       if (priority == PRIO_DARWIN_BG) {
-               /*
-                * For PRIO_DARWIN_PROCESS (thread is NULL), simply mark
-                * the sockets with the background flag.  There's nothing
-                * to do here for the PRIO_DARWIN_THREAD case.
-                */
-               if (thread == NULL) {
-                       proc_fdlock(p);
-                       fdp = p->p_fd;
+       int error = 0;
+       int role = 0;
 
-                       for (i = 0; i < fdp->fd_nfiles; i++) {
-                               struct socket       *sockp;
+       kauth_cred_t ucred, target_cred;
 
-                               fp = fdp->fd_ofiles[i];
-                               if (fp == NULL || (fdp->fd_ofileflags[i] & UF_RESERVED) != 0 ||
-                                               fp->f_fglob->fg_type != DTYPE_SOCKET) {
-                                       continue;
-                               }
-                               sockp = (struct socket *)fp->f_fglob->fg_data;
-                               socket_set_traffic_mgt_flags(sockp, TRAFFIC_MGT_SO_BACKGROUND);
-                               sockp->so_background_thread = NULL;
-                       }
-                       proc_fdunlock(p);
-               }
+       ucred = kauth_cred_get();
+       target_cred = kauth_cred_proc_ref(targetp);
 
-       } else {
+       if (!kauth_cred_issuser(ucred) && kauth_cred_getruid(ucred) &&
+           kauth_cred_getuid(ucred) != kauth_cred_getuid(target_cred) &&
+           kauth_cred_getruid(ucred) != kauth_cred_getuid(target_cred)) {
+               error = EPERM;
+               goto out;
+       }
 
-               /* disable networking IO throttle.
-                * NOTE - It is a known limitation of the current design that we 
-                * could potentially clear TRAFFIC_MGT_SO_BACKGROUND bit for 
-                * sockets created by other threads within this process.  
-                */
-               proc_fdlock(p);
-               fdp = p->p_fd;
-               for ( i = 0; i < fdp->fd_nfiles; i++ ) {
-                       struct socket       *sockp;
-
-                       fp = fdp->fd_ofiles[ i ];
-                       if ( fp == NULL || (fdp->fd_ofileflags[ i ] & UF_RESERVED) != 0 ||
-                                       fp->f_fglob->fg_type != DTYPE_SOCKET ) {
-                               continue;
-                       }
-                       sockp = (struct socket *)fp->f_fglob->fg_data;
-                       /* skip if only clearing this thread's sockets */
-                       if ((thread) && (sockp->so_background_thread != thread)) {
-                               continue;
-                       }
-                       socket_clear_traffic_mgt_flags(sockp, TRAFFIC_MGT_SO_BACKGROUND);
-                       sockp->so_background_thread = NULL;
+       if (curp != targetp) {
+#if CONFIG_MACF
+               if ((error = mac_proc_check_sched(curp, targetp))) {
+                       goto out;
                }
-               proc_fdunlock(p);
+#endif
        }
+
+       role = proc_get_task_policy(proc_task(targetp), TASK_POLICY_ATTRIBUTE, TASK_POLICY_ROLE);
+
+       *priority = proc_task_role_to_darwin_role(role);
+
+out:
+       kauth_cred_unref(&target_cred);
+       return error;
 }
 
 
-/*
- * do_background_thread
- * Returns:    0                       Success
- * XXX - todo - does this need a MACF hook?
- *
- * NOTE: To maintain binary compatibility with PRIO_DARWIN_THREAD with respect
- *      to network traffic management, UT_BACKGROUND_TRAFFIC_MGT is set/cleared
- *      along with UT_BACKGROUND flag, as the latter alone no longer implies
- *      any form of traffic regulation (it simply means that the thread is
- *      background.)  With PRIO_DARWIN_PROCESS, any form of network traffic
- *      management must be explicitly requested via whatever means appropriate,
- *      and only TRAFFIC_MGT_SO_BACKGROUND is set via do_background_socket().
- */
 static int
-do_background_thread(struct proc *curp __unused, thread_t thread, int priority)
+get_background_proc(struct proc *curp, struct proc *targetp, int *priority)
 {
-       struct uthread                                          *ut;
-#if !CONFIG_EMBEDDED
+       int external = 0;
        int error = 0;
-#else /* !CONFIG_EMBEDDED */
-       thread_precedence_policy_data_t         policy;
-#endif /* !CONFIG_EMBEDDED */
-       
-       ut = get_bsdthread_info(thread);
+       kauth_cred_t ucred, target_cred;
 
-       /* Backgrounding is unsupported for threads in vfork */
-       if ( (ut->uu_flag & UT_VFORK) != 0) {
-               return(EPERM);
-       }
+       ucred = kauth_cred_get();
+       target_cred = kauth_cred_proc_ref(targetp);
 
-#if !CONFIG_EMBEDDED
-       error = proc_set1_bgthreadpolicy(curp->task, thread_tid(thread), priority);
-       return(error);
-#else /* !CONFIG_EMBEDDED */
-       if ( (priority & PRIO_DARWIN_BG) == 0 ) {
-               /* turn off backgrounding of thread */
-               if ( (ut->uu_flag & UT_BACKGROUND) == 0 ) {
-                       /* already off */
-                       return(0);
-               }
+       if (!kauth_cred_issuser(ucred) && kauth_cred_getruid(ucred) &&
+           kauth_cred_getuid(ucred) != kauth_cred_getuid(target_cred) &&
+           kauth_cred_getruid(ucred) != kauth_cred_getuid(target_cred)) {
+               error = EPERM;
+               goto out;
+       }
 
-               /*
-                * Clear background bit in thread and disable disk IO
-                * throttle as well as network traffic management.
-                * The corresponding socket flags for sockets created by
-                * this thread will be cleared in do_background_socket().
-                */
-               ut->uu_flag &= ~(UT_BACKGROUND | UT_BACKGROUND_TRAFFIC_MGT);
-               ut->uu_iopol_disk = IOPOL_NORMAL;
+       external = (curp == targetp) ? TASK_POLICY_INTERNAL : TASK_POLICY_EXTERNAL;
 
-               /* reset thread priority (we did not save previous value) */
-               policy.importance = 0;
-               thread_policy_set( thread, THREAD_PRECEDENCE_POLICY,
-                                                  (thread_policy_t)&policy,
-                                                  THREAD_PRECEDENCE_POLICY_COUNT );
-               return(0);
-       }
-       
-       /* background this thread */
-       if ( (ut->uu_flag & UT_BACKGROUND) != 0 ) {
-               /* already backgrounded */
-               return(0);
-       }
+       *priority = proc_get_task_policy(current_task(), external, TASK_POLICY_DARWIN_BG);
 
-       /*
-        * Tag thread as background and throttle disk IO, as well
-        * as regulate network traffics.  Future sockets created
-        * by this thread will have their corresponding socket
-        * flags set at socket create time.
-        */
-       ut->uu_flag |= (UT_BACKGROUND | UT_BACKGROUND_TRAFFIC_MGT);
-       ut->uu_iopol_disk = IOPOL_THROTTLE;
-
-       policy.importance = INT_MIN;
-       thread_policy_set( thread, THREAD_PRECEDENCE_POLICY,
-                                          (thread_policy_t)&policy,
-                                          THREAD_PRECEDENCE_POLICY_COUNT );
-
-       /* throttle networking IO happens in socket( ) syscall.
-        * If UT_{BACKGROUND,BACKGROUND_TRAFFIC_MGT} is set in the current
-        * thread then TRAFFIC_MGT_SO_{BACKGROUND,BG_REGULATE} is set.
-        * Existing sockets are taken care of by do_background_socket().
-        */
-#endif /* !CONFIG_EMBEDDED */
-       return(0);
+out:
+       kauth_cred_unref(&target_cred);
+       return error;
 }
 
-#if CONFIG_EMBEDDED
-int mach_do_background_thread(thread_t thread, int prio);
-
-int
-mach_do_background_thread(thread_t thread, int prio)
+static int
+do_background_proc(struct proc *curp, struct proc *targetp, int priority)
 {
-       int                     error           = 0;
-       struct proc             *curp           = NULL;
-       struct proc             *targetp        = NULL;
-       kauth_cred_t    ucred;
+#if !CONFIG_MACF
+#pragma unused(curp)
+#endif
+       int error = 0;
+       kauth_cred_t ucred;
+       kauth_cred_t target_cred;
+       int external;
+       int enable;
 
-       targetp = get_bsdtask_info(get_threadtask(thread));
-       if (!targetp) {
-               return KERN_INVALID_ARGUMENT;
+       ucred = kauth_cred_get();
+       target_cred = kauth_cred_proc_ref(targetp);
+
+       if (!kauth_cred_issuser(ucred) && kauth_cred_getruid(ucred) &&
+           kauth_cred_getuid(ucred) != kauth_cred_getuid(target_cred) &&
+           kauth_cred_getruid(ucred) != kauth_cred_getuid(target_cred)) {
+               error = EPERM;
+               goto out;
        }
 
-       curp = proc_self();
-       if (curp == PROC_NULL) {
-               return KERN_FAILURE;
+#if CONFIG_MACF
+       error = mac_proc_check_sched(curp, targetp);
+       if (error) {
+               goto out;
        }
+#endif
 
-       ucred = kauth_cred_proc_ref(curp);
+       external = (curp == targetp) ? TASK_POLICY_INTERNAL : TASK_POLICY_EXTERNAL;
 
-       if (suser(ucred, NULL) && curp != targetp) {
-               error = KERN_PROTECTION_FAILURE;
+       switch (priority) {
+       case PRIO_DARWIN_BG:
+               enable = TASK_POLICY_ENABLE;
+               break;
+       case PRIO_DARWIN_NONUI:
+               /* ignored for compatibility */
                goto out;
+       default:
+               /* TODO: EINVAL if priority != 0 */
+               enable = TASK_POLICY_DISABLE;
+               break;
        }
 
-       error = do_background_thread(curp, thread, prio);
-       if (!error) {
-               (void) do_background_socket(curp, thread, prio);
-       } else {
-               if (error == EPERM) {
-                       error = KERN_PROTECTION_FAILURE;
-               } else {
-                       error = KERN_FAILURE;
-               }
-       }
+       proc_set_task_policy(proc_task(targetp), external, TASK_POLICY_DARWIN_BG, enable);
 
 out:
-       proc_rele(curp);
-       kauth_cred_unref(&ucred);
+       kauth_cred_unref(&target_cred);
        return error;
 }
-#endif /* CONFIG_EMBEDDED */
 
-#if CONFIG_EMBEDDED
-/*
- * If the thread or its proc has been put into the background
- * with setpriority(PRIO_DARWIN_{THREAD,PROCESS}, *, PRIO_DARWIN_BG),
- * report that status.
- *
- * Returns: PRIO_DARWIN_BG if background
- *                     0 if foreground
- */
-int
-uthread_get_background_state(uthread_t uth)
+static void
+do_background_socket(struct proc *p, thread_t thread)
 {
-       proc_t p = uth->uu_proc;
-       if (p && (p->p_lflag & P_LBACKGROUND))
-               return PRIO_DARWIN_BG;
-       
-       if (uth->uu_flag & UT_BACKGROUND)
-               return PRIO_DARWIN_BG;
+#if SOCKETS
+       struct fileproc *fp;
+       int              background = false;
+#if NECP
+       int              update_necp = false;
+#endif /* NECP */
 
-       return 0;
-}
-#endif /* CONFIG_EMBEDDED */
+       proc_fdlock(p);
 
-/*
+       if (thread != THREAD_NULL) {
+               background = proc_get_effective_thread_policy(thread, TASK_POLICY_ALL_SOCKETS_BG);
+       } else {
+               background = proc_get_effective_task_policy(proc_task(p), TASK_POLICY_ALL_SOCKETS_BG);
+       }
+
+       if (background) {
+               /*
+                * For PRIO_DARWIN_PROCESS (thread is NULL), simply mark
+                * the sockets with the background flag.  There's nothing
+                * to do here for the PRIO_DARWIN_THREAD case.
+                */
+               if (thread == THREAD_NULL) {
+                       fdt_foreach(fp, p) {
+                               if (FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_SOCKET) {
+                                       struct socket *sockp = (struct socket *)fp->fp_glob->fg_data;
+                                       socket_set_traffic_mgt_flags(sockp, TRAFFIC_MGT_SO_BACKGROUND);
+                                       sockp->so_background_thread = NULL;
+                               }
+#if NECP
+                               else if (FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_NETPOLICY) {
+                                       if (necp_set_client_as_background(p, fp, background)) {
+                                               update_necp = true;
+                                       }
+                               }
+#endif /* NECP */
+                       }
+               }
+       } else {
+               /* disable networking IO throttle.
+                * NOTE - It is a known limitation of the current design that we
+                * could potentially clear TRAFFIC_MGT_SO_BACKGROUND bit for
+                * sockets created by other threads within this process.
+                */
+               fdt_foreach(fp, p) {
+                       struct socket *sockp;
+
+                       if (FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_SOCKET) {
+                               sockp = (struct socket *)fp->fp_glob->fg_data;
+                               /* skip if only clearing this thread's sockets */
+                               if ((thread) && (sockp->so_background_thread != thread)) {
+                                       continue;
+                               }
+                               socket_clear_traffic_mgt_flags(sockp, TRAFFIC_MGT_SO_BACKGROUND);
+                               sockp->so_background_thread = NULL;
+                       }
+#if NECP
+                       else if (FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_NETPOLICY) {
+                               if (necp_set_client_as_background(p, fp, background)) {
+                                       update_necp = true;
+                               }
+                       }
+#endif /* NECP */
+               }
+       }
+
+       proc_fdunlock(p);
+
+#if NECP
+       if (update_necp) {
+               necp_update_all_clients();
+       }
+#endif /* NECP */
+#else
+#pragma unused(p, thread)
+#endif
+}
+
+
+/*
+ * do_background_thread
+ *
+ * Requires: thread reference
+ *
+ * Returns:     0                       Success
+ *              EPERM                   Tried to background while in vfork
+ * XXX - todo - does this need a MACF hook?
+ */
+static int
+do_background_thread(thread_t thread, int priority)
+{
+       struct uthread *ut;
+       int enable, external;
+       int rv = 0;
+
+       ut = get_bsdthread_info(thread);
+
+       /* Backgrounding is unsupported for threads in vfork */
+       if ((ut->uu_flag & UT_VFORK) != 0) {
+               return EPERM;
+       }
+
+       /* Backgrounding is unsupported for workq threads */
+       if (thread_is_static_param(thread)) {
+               return EPERM;
+       }
+
+       /* Not allowed to combine QoS and DARWIN_BG, doing so strips the QoS */
+       if (thread_has_qos_policy(thread)) {
+               thread_remove_qos_policy(thread);
+               rv = EIDRM;
+       }
+
+       /* TODO: Fail if someone passes something besides 0 or PRIO_DARWIN_BG */
+       enable   = (priority == PRIO_DARWIN_BG) ? TASK_POLICY_ENABLE   : TASK_POLICY_DISABLE;
+       external = (current_thread() == thread) ? TASK_POLICY_INTERNAL : TASK_POLICY_EXTERNAL;
+
+       proc_set_thread_policy(thread, external, TASK_POLICY_DARWIN_BG, enable);
+
+       return rv;
+}
+
+
+/*
  * Returns:    0                       Success
  *     copyin:EFAULT
  *     dosetrlimit:
@@ -762,16 +917,16 @@ setrlimit(struct proc *p, struct setrlimit_args *uap, __unused int32_t *retval)
        int error;
 
        if ((error = copyin(uap->rlp, (caddr_t)&alim,
-           sizeof (struct rlimit))))
-               return (error);
+           sizeof(struct rlimit)))) {
+               return error;
+       }
 
-       return (dosetrlimit(p, uap->which, &alim));
+       return dosetrlimit(p, uap->which, &alim);
 }
 
 /*
  * Returns:    0                       Success
  *             EINVAL
- *             ENOMEM                  Cannot copy limit structure
  *     suser:EPERM
  *
  * Notes:      EINVAL is returned both for invalid arguments, and in the
@@ -779,68 +934,82 @@ setrlimit(struct proc *p, struct setrlimit_args *uap, __unused int32_t *retval)
  *             in excess of the requested limit.
  */
 int
-dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
+dosetrlimit(struct proc *p, u_int which, struct rlimit *newrlim)
 {
-       struct rlimit *alimp;
-       int error;
-       kern_return_t   kr;
-       int posix = (which & _RLIMIT_POSIX_FLAG) ? 1 : 0;
+       struct rlimit        rlim;
+       int                  error;
+       kern_return_t        kr;
+       int                  posix = (which & _RLIMIT_POSIX_FLAG) ? 1 : 0;
 
        /* Mask out POSIX flag, saved above */
        which &= ~_RLIMIT_POSIX_FLAG;
 
-       if (which >= RLIM_NLIMITS)
-               return (EINVAL);
-
-       alimp = &p->p_rlimit[which];
-       if (limp->rlim_cur > limp->rlim_max)
+       /* Unknown resource */
+       if (which >= RLIM_NLIMITS) {
                return EINVAL;
-
-       if (limp->rlim_cur > alimp->rlim_max || 
-           limp->rlim_max > alimp->rlim_max)
-               if ((error = suser(kauth_cred_get(), &p->p_acflag))) {
-                       return (error);
        }
 
-       proc_limitblock(p);
+       /*
+        * Take a snapshot of the current rlimit values and read this throughout
+        * this routine. This minimizes the critical sections and allow other
+        * processes in the system to access the plimit while we are in the
+        * middle of this setrlimit call.
+        */
+       proc_lock(p);
+       rlim = p->p_limit->pl_rlimit[which];
+       proc_unlock(p);
 
-       if ((error = proc_limitreplace(p)) != 0) {
-               proc_limitunblock(p);
-               return(error);
+       error = 0;
+       /* Sanity check: new soft limit cannot exceed new hard limit */
+       if (newrlim->rlim_cur > newrlim->rlim_max) {
+               error = EINVAL;
+       }
+       /*
+        * Sanity check: only super-user may raise the hard limit.
+        * newrlim->rlim_cur > rlim.rlim_max implies that the call is increasing the hard limit as well.
+        */
+       else if (newrlim->rlim_cur > rlim.rlim_max || newrlim->rlim_max > rlim.rlim_max) {
+               /* suser() returns 0 if the calling thread is super user. */
+               error = suser(kauth_cred_get(), &p->p_acflag);
        }
 
-       alimp = &p->p_rlimit[which];
-       
-       switch (which) {
+       if (error) {
+               /* Invalid setrlimit request: EINVAL or EPERM */
+               return error;
+       }
 
+       /* Only one thread is able to change the current process's rlimit values */
+       proc_lock(p);
+       proc_limitblock(p);
+       proc_unlock(p);
+
+       /* We have the reader lock of the process's plimit so it's safe to read the rlimit values */
+       switch (which) {
        case RLIMIT_CPU:
-               if (limp->rlim_cur == RLIM_INFINITY) {
+               if (newrlim->rlim_cur == RLIM_INFINITY) {
                        task_vtimer_clear(p->task, TASK_VTIMER_RLIM);
                        timerclear(&p->p_rlim_cpu);
-               }
-               else {
-                       task_absolutetime_info_data_t   tinfo;
-                       mach_msg_type_number_t                  count;
-                       struct timeval                                  ttv, tv;
-                       clock_sec_t                                             tv_sec;
-                       clock_usec_t                                    tv_usec;
+               } else {
+                       task_absolutetime_info_data_t   tinfo;
+                       mach_msg_type_number_t          count;
+                       struct timeval                  ttv, tv;
+                       clock_sec_t                     tv_sec;
+                       clock_usec_t                    tv_usec;
 
                        count = TASK_ABSOLUTETIME_INFO_COUNT;
-                       task_info(p->task, TASK_ABSOLUTETIME_INFO,
-                                                               (task_info_t)&tinfo, &count);
-                       absolutetime_to_microtime(tinfo.total_user + tinfo.total_system,
-                                                                         &tv_sec, &tv_usec);
+                       task_info(p->task, TASK_ABSOLUTETIME_INFO, (task_info_t)&tinfo, &count);
+                       absolutetime_to_microtime(tinfo.total_user + tinfo.total_system, &tv_sec, &tv_usec);
                        ttv.tv_sec = tv_sec;
                        ttv.tv_usec = tv_usec;
 
-                       tv.tv_sec = (limp->rlim_cur > __INT_MAX__ ? __INT_MAX__ : limp->rlim_cur);
+                       tv.tv_sec = (newrlim->rlim_cur > __INT_MAX__ ? __INT_MAX__ : (__darwin_time_t)newrlim->rlim_cur);
                        tv.tv_usec = 0;
                        timersub(&tv, &ttv, &p->p_rlim_cpu);
 
                        timerclear(&tv);
-                       if (timercmp(&p->p_rlim_cpu, &tv, >))
+                       if (timercmp(&p->p_rlim_cpu, &tv, >)) {
                                task_vtimer_set(p->task, TASK_VTIMER_RLIM);
-                       else {
+                       else {
                                task_vtimer_clear(p->task, TASK_VTIMER_RLIM);
 
                                timerclear(&p->p_rlim_cpu);
@@ -851,30 +1020,39 @@ dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
                break;
 
        case RLIMIT_DATA:
-               if (limp->rlim_cur > maxdmap)
-                       limp->rlim_cur = maxdmap;
-               if (limp->rlim_max > maxdmap)
-                       limp->rlim_max = maxdmap;
+               if (newrlim->rlim_cur > maxdmap) {
+                       newrlim->rlim_cur = maxdmap;
+               }
+               if (newrlim->rlim_max > maxdmap) {
+                       newrlim->rlim_max = maxdmap;
+               }
                break;
 
        case RLIMIT_STACK:
+               if (p->p_lflag & P_LCUSTOM_STACK) {
+                       /* Process has a custom stack set - rlimit cannot be used to change it */
+                       error = EINVAL;
+                       goto out;
+               }
+
                /* Disallow illegal stack size instead of clipping */
-               if (limp->rlim_cur > maxsmap ||
-                   limp->rlim_max > maxsmap) {
+               if (newrlim->rlim_cur > maxsmap ||
+                   newrlim->rlim_max > maxsmap) {
                        if (posix) {
                                error = EINVAL;
                                goto out;
-                       }
-                       else {
-                               /* 
-                                * 4797860 - workaround poorly written installers by 
-                                * doing previous implementation (< 10.5) when caller 
+                       } else {
+                               /*
+                                * 4797860 - workaround poorly written installers by
+                                * doing previous implementation (< 10.5) when caller
                                 * is non-POSIX conforming.
                                 */
-                               if (limp->rlim_cur > maxsmap) 
-                                       limp->rlim_cur = maxsmap;
-                               if (limp->rlim_max > maxsmap) 
-                                       limp->rlim_max = maxsmap;
+                               if (newrlim->rlim_cur > maxsmap) {
+                                       newrlim->rlim_cur = maxsmap;
+                               }
+                               if (newrlim->rlim_max > maxsmap) {
+                                       newrlim->rlim_max = maxsmap;
+                               }
                        }
                }
 
@@ -883,72 +1061,39 @@ dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
                 * "rlim_cur" bytes accessible.  If stack limit is going
                 * up make more accessible, if going down make inaccessible.
                 */
-               if (limp->rlim_cur > alimp->rlim_cur) {
-                       user_addr_t addr;
-                       user_size_t size;
-                       
-                               /* grow stack */
-                               size = round_page_64(limp->rlim_cur);
-                               size -= round_page_64(alimp->rlim_cur);
-
-#if STACK_GROWTH_UP
-                               /* go to top of current stack */
-                       addr = p->user_stack + round_page_64(alimp->rlim_cur);
-#else  /* STACK_GROWTH_UP */
-                       addr = p->user_stack - round_page_64(limp->rlim_cur);
-#endif /* STACK_GROWTH_UP */
-                       kr = mach_vm_protect(current_map(), 
-                                            addr, size,
-                                            FALSE, VM_PROT_DEFAULT);
+               if (newrlim->rlim_cur > rlim.rlim_cur) {
+                       mach_vm_offset_t addr;
+                       mach_vm_size_t size;
+
+                       /* grow stack */
+                       size = round_page_64(newrlim->rlim_cur);
+                       size -= round_page_64(rlim.rlim_cur);
+
+                       addr = (mach_vm_offset_t)(p->user_stack - round_page_64(newrlim->rlim_cur));
+                       kr = mach_vm_protect(current_map(), addr, size, FALSE, VM_PROT_DEFAULT);
                        if (kr != KERN_SUCCESS) {
                                error =  EINVAL;
                                goto out;
                        }
-               } else if (limp->rlim_cur < alimp->rlim_cur) {
-                       user_addr_t addr;
-                       user_size_t size;
-                       user_addr_t cur_sp;
+               } else if (newrlim->rlim_cur < rlim.rlim_cur) {
+                       mach_vm_offset_t addr;
+                       mach_vm_size_t size;
+                       uint64_t cur_sp;
 
-                               /* shrink stack */
+                       /* shrink stack */
 
                        /*
                         * First check if new stack limit would agree
                         * with current stack usage.
                         * Get the current thread's stack pointer...
                         */
-                       cur_sp = thread_adjuserstack(current_thread(),
-                                                    0);
-#if STACK_GROWTH_UP
-                       if (cur_sp >= p->user_stack &&
-                           cur_sp < (p->user_stack +
-                                     round_page_64(alimp->rlim_cur))) {
-                               /* current stack pointer is in main stack */
-                               if (cur_sp >= (p->user_stack +
-                                              round_page_64(limp->rlim_cur))) {
-                                       /*
-                                        * New limit would cause
-                                        * current usage to be invalid:
-                                        * reject new limit.
-                                        */
-                                       error =  EINVAL;
-                                       goto out;
-                       }
-                       } else {
-                               /* not on the main stack: reject */
-                               error =  EINVAL;
-                               goto out;
-               }
-                                
-#else  /* STACK_GROWTH_UP */
+                       cur_sp = thread_adjuserstack(current_thread(), 0);
                        if (cur_sp <= p->user_stack &&
-                           cur_sp > (p->user_stack -
-                                     round_page_64(alimp->rlim_cur))) {
+                           cur_sp > (p->user_stack - round_page_64(rlim.rlim_cur))) {
                                /* stack pointer is in main stack */
-                               if (cur_sp <= (p->user_stack -
-                                              round_page_64(limp->rlim_cur))) {
+                               if (cur_sp <= (p->user_stack - round_page_64(newrlim->rlim_cur))) {
                                        /*
-                                        * New limit would cause
-                                        * current usage to be invalid:
+                                        * New limit would cause current usage to be invalid:
                                         * reject new limit.
                                         */
                                        error =  EINVAL;
@@ -959,20 +1104,13 @@ dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
                                error =  EINVAL;
                                goto out;
                        }
-#endif /* STACK_GROWTH_UP */
-                               
-                       size = round_page_64(alimp->rlim_cur);
-                       size -= round_page_64(limp->rlim_cur);
-
-#if STACK_GROWTH_UP
-                       addr = p->user_stack + round_page_64(limp->rlim_cur);
-#else  /* STACK_GROWTH_UP */
-                       addr = p->user_stack - round_page_64(alimp->rlim_cur);
-#endif /* STACK_GROWTH_UP */
-
-                       kr = mach_vm_protect(current_map(),
-                                            addr, size,
-                                            FALSE, VM_PROT_NONE);
+
+                       size = round_page_64(rlim.rlim_cur);
+                       size -= round_page_64(rlim.rlim_cur);
+
+                       addr = (mach_vm_offset_t)(p->user_stack - round_page_64(rlim.rlim_cur));
+
+                       kr = mach_vm_protect(current_map(), addr, size, FALSE, VM_PROT_NONE);
                        if (kr != KERN_SUCCESS) {
                                error =  EINVAL;
                                goto out;
@@ -983,58 +1121,32 @@ dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
                break;
 
        case RLIMIT_NOFILE:
-               /* 
-                * Only root can set the maxfiles limits, as it is
-                * systemwide resource.  If we are expecting POSIX behavior,
-                * instead of clamping the value, return EINVAL.  We do this
-                * because historically, people have been able to attempt to
-                * set RLIM_INFINITY to get "whatever the maximum is".
-               */
-               if ( is_suser() ) {
-                       if (limp->rlim_cur != alimp->rlim_cur &&
-                           limp->rlim_cur > (rlim_t)maxfiles) {
-                               if (posix) {
-                                       error =  EINVAL;
-                                       goto out;
-                               }
-                               limp->rlim_cur = maxfiles;
-                       }
-                       if (limp->rlim_max != alimp->rlim_max &&
-                           limp->rlim_max > (rlim_t)maxfiles)
-                               limp->rlim_max = maxfiles;
-               }
-               else {
-                       if (limp->rlim_cur != alimp->rlim_cur &&
-                           limp->rlim_cur > (rlim_t)maxfilesperproc) {
-                               if (posix) {
-                                       error =  EINVAL;
-                                       goto out;
-                               }
-                               limp->rlim_cur = maxfilesperproc;
-                       }
-                       if (limp->rlim_max != alimp->rlim_max &&
-                           limp->rlim_max > (rlim_t)maxfilesperproc)
-                               limp->rlim_max = maxfilesperproc;
-               }
+               /*
+                * Nothing to be done here as we already performed the sanity checks before entering the switch code block.
+                * The real NOFILE limits enforced by the kernel is capped at MIN(RLIMIT_NOFILE, maxfilesperproc)
+                */
                break;
 
        case RLIMIT_NPROC:
-               /* 
+               /*
                 * Only root can set to the maxproc limits, as it is
                 * systemwide resource; all others are limited to
                 * maxprocperuid (presumably less than maxproc).
                 */
-               if ( is_suser() ) {
-                       if (limp->rlim_cur > (rlim_t)maxproc)
-                               limp->rlim_cur = maxproc;
-                       if (limp->rlim_max > (rlim_t)maxproc)
-                               limp->rlim_max = maxproc;
-               } 
-               else {
-                       if (limp->rlim_cur > (rlim_t)maxprocperuid)
-                               limp->rlim_cur = maxprocperuid;
-                       if (limp->rlim_max > (rlim_t)maxprocperuid)
-                               limp->rlim_max = maxprocperuid;
+               if (kauth_cred_issuser(kauth_cred_get())) {
+                       if (newrlim->rlim_cur > (rlim_t)maxproc) {
+                               newrlim->rlim_cur = maxproc;
+                       }
+                       if (newrlim->rlim_max > (rlim_t)maxproc) {
+                               newrlim->rlim_max = maxproc;
+                       }
+               } else {
+                       if (newrlim->rlim_cur > (rlim_t)maxprocperuid) {
+                               newrlim->rlim_cur = maxprocperuid;
+                       }
+                       if (newrlim->rlim_max > (rlim_t)maxprocperuid) {
+                               newrlim->rlim_max = maxprocperuid;
+                       }
                }
                break;
 
@@ -1042,25 +1154,43 @@ dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
                /*
                 * Tell the Mach VM layer about the new limit value.
                 */
-
-               vm_map_set_user_wire_limit(current_map(), limp->rlim_cur);
+               newrlim->rlim_cur = (vm_size_t)newrlim->rlim_cur;
+               vm_map_set_user_wire_limit(current_map(), (vm_size_t)newrlim->rlim_cur);
                break;
-               
        } /* switch... */
-       proc_lock(p);
-       *alimp = *limp;
-       proc_unlock(p);
+
+       /* Everything checks out and we are now ready to update the rlimit */
        error = 0;
+
 out:
-       proc_limitunblock(p);
-       return (error);
+
+       if (error == 0) {
+               /*
+                * COW the current plimit if it's shared, otherwise update it in place.
+                * Finally unblock other threads wishing to change plimit.
+                */
+               proc_lock(p);
+               proc_limitupdate(p, newrlim, (uint8_t)which);
+               proc_limitunblock(p);
+               proc_unlock(p);
+       } else {
+               /*
+                * This setrlimit has failed, just leave the plimit as is and unblock other
+                * threads wishing to change plimit.
+                */
+               proc_lock(p);
+               proc_limitunblock(p);
+               proc_unlock(p);
+       }
+
+       return error;
 }
 
 /* ARGSUSED */
 int
 getrlimit(struct proc *p, struct getrlimit_args *uap, __unused int32_t *retval)
 {
-       struct rlimit lim;
+       struct rlimit lim = {};
 
        /*
         * Take out flag now in case we need to use it to trigger variant
@@ -1068,11 +1198,12 @@ getrlimit(struct proc *p, struct getrlimit_args *uap, __unused int32_t *retval)
         */
        uap->which &= ~_RLIMIT_POSIX_FLAG;
 
-       if (uap->which >= RLIM_NLIMITS)
-               return (EINVAL);
+       if (uap->which >= RLIM_NLIMITS) {
+               return EINVAL;
+       }
        proc_limitget(p, uap->which, &lim);
-       return (copyout((caddr_t)&lim,
-                       uap->rlp, sizeof (struct rlimit)));
+       return copyout((caddr_t)&lim,
+                  uap->rlp, sizeof(struct rlimit));
 }
 
 /*
@@ -1083,25 +1214,26 @@ getrlimit(struct proc *p, struct getrlimit_args *uap, __unused int32_t *retval)
 void
 calcru(struct proc *p, struct timeval *up, struct timeval *sp, struct timeval *ip)
 {
-       task_t                  task;
+       task_t                  task;
 
        timerclear(up);
        timerclear(sp);
-       if (ip != NULL)
+       if (ip != NULL) {
                timerclear(ip);
+       }
 
        task = p->task;
        if (task) {
-               task_basic_info_32_data_t tinfo;
+               mach_task_basic_info_data_t tinfo;
                task_thread_times_info_data_t ttimesinfo;
                task_events_info_data_t teventsinfo;
                mach_msg_type_number_t task_info_count, task_ttimes_count;
                mach_msg_type_number_t task_events_count;
-               struct timeval ut,st;
+               struct timeval ut, st;
 
-               task_info_count = TASK_BASIC_INFO_32_COUNT;
-               task_info(task, TASK_BASIC2_INFO_32,
-                         (task_info_t)&tinfo, &task_info_count);
+               task_info_count = MACH_TASK_BASIC_INFO_COUNT;
+               task_info(task, MACH_TASK_BASIC_INFO,
+                   (task_info_t)&tinfo, &task_info_count);
                ut.tv_sec = tinfo.user_time.seconds;
                ut.tv_usec = tinfo.user_time.microseconds;
                st.tv_sec = tinfo.system_time.seconds;
@@ -1111,7 +1243,7 @@ calcru(struct proc *p, struct timeval *up, struct timeval *sp, struct timeval *i
 
                task_ttimes_count = TASK_THREAD_TIMES_INFO_COUNT;
                task_info(task, TASK_THREAD_TIMES_INFO,
-                         (task_info_t)&ttimesinfo, &task_ttimes_count);
+                   (task_info_t)&ttimesinfo, &task_ttimes_count);
 
                ut.tv_sec = ttimesinfo.user_time.seconds;
                ut.tv_usec = ttimesinfo.user_time.microseconds;
@@ -1122,21 +1254,22 @@ calcru(struct proc *p, struct timeval *up, struct timeval *sp, struct timeval *i
 
                task_events_count = TASK_EVENTS_INFO_COUNT;
                task_info(task, TASK_EVENTS_INFO,
-                         (task_info_t)&teventsinfo, &task_events_count);
+                   (task_info_t)&teventsinfo, &task_events_count);
 
                /*
                 * No need to lock "p":  this does not need to be
                 * completely consistent, right ?
                 */
                p->p_stats->p_ru.ru_minflt = (teventsinfo.faults -
-                                             teventsinfo.pageins);
+                   teventsinfo.pageins);
                p->p_stats->p_ru.ru_majflt = teventsinfo.pageins;
                p->p_stats->p_ru.ru_nivcsw = (teventsinfo.csw -
-                                             p->p_stats->p_ru.ru_nvcsw);
-               if (p->p_stats->p_ru.ru_nivcsw < 0)
+                   p->p_stats->p_ru.ru_nvcsw);
+               if (p->p_stats->p_ru.ru_nivcsw < 0) {
                        p->p_stats->p_ru.ru_nivcsw = 0;
+               }
 
-               p->p_stats->p_ru.ru_maxrss = tinfo.resident_size;
+               p->p_stats->p_ru.ru_maxrss = (long)tinfo.resident_size_max;
        }
 }
 
@@ -1148,10 +1281,10 @@ int
 getrusage(struct proc *p, struct getrusage_args *uap, __unused int32_t *retval)
 {
        struct rusage *rup, rubuf;
-       struct user64_rusage rubuf64;
-       struct user32_rusage rubuf32;
-       size_t retsize = sizeof(rubuf);                 /* default: 32 bits */
-       caddr_t retbuf = (caddr_t)&rubuf;               /* default: 32 bits */
+       struct user64_rusage rubuf64 = {};
+       struct user32_rusage rubuf32 = {};
+       size_t retsize = sizeof(rubuf);                 /* default: 32 bits */
+       caddr_t retbuf = (caddr_t)&rubuf;               /* default: 32 bits */
        struct timeval utime;
        struct timeval stime;
 
@@ -1177,7 +1310,7 @@ getrusage(struct proc *p, struct getrusage_args *uap, __unused int32_t *retval)
                break;
 
        default:
-               return (EINVAL);
+               return EINVAL;
        }
        if (IS_64BIT_PROCESS(p)) {
                retsize = sizeof(rubuf64);
@@ -1189,7 +1322,7 @@ getrusage(struct proc *p, struct getrusage_args *uap, __unused int32_t *retval)
                munge_user32_rusage(&rubuf, &rubuf32);
        }
 
-       return (copyout(retbuf, uap->rusage, retsize));
+       return copyout(retbuf, uap->rusage, retsize);
 }
 
 void
@@ -1200,118 +1333,291 @@ ruadd(struct rusage *ru, struct rusage *ru2)
 
        timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
        timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
-       if (ru->ru_maxrss < ru2->ru_maxrss)
+       if (ru->ru_maxrss < ru2->ru_maxrss) {
                ru->ru_maxrss = ru2->ru_maxrss;
+       }
        ip = &ru->ru_first; ip2 = &ru2->ru_first;
-       for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
+       for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--) {
                *ip++ += *ip2++;
+       }
 }
 
+/*
+ * Add the rusage stats of child in parent.
+ *
+ * It adds rusage statistics of child process and statistics of all its
+ * children to its parent.
+ *
+ * Note: proc lock of parent should be held while calling this function.
+ */
 void
-proc_limitget(proc_t p, int which, struct rlimit * limp)
+update_rusage_info_child(struct rusage_info_child *ri, rusage_info_current *ri_current)
 {
-       proc_list_lock();
-       limp->rlim_cur = p->p_rlimit[which].rlim_cur;
-       limp->rlim_max = p->p_rlimit[which].rlim_max;
-       proc_list_unlock();
+       ri->ri_child_user_time += (ri_current->ri_user_time +
+           ri_current->ri_child_user_time);
+       ri->ri_child_system_time += (ri_current->ri_system_time +
+           ri_current->ri_child_system_time);
+       ri->ri_child_pkg_idle_wkups += (ri_current->ri_pkg_idle_wkups +
+           ri_current->ri_child_pkg_idle_wkups);
+       ri->ri_child_interrupt_wkups += (ri_current->ri_interrupt_wkups +
+           ri_current->ri_child_interrupt_wkups);
+       ri->ri_child_pageins += (ri_current->ri_pageins +
+           ri_current->ri_child_pageins);
+       ri->ri_child_elapsed_abstime += ((ri_current->ri_proc_exit_abstime -
+           ri_current->ri_proc_start_abstime) + ri_current->ri_child_elapsed_abstime);
 }
 
-
-void
-proc_limitdrop(proc_t p, int exiting)
+/*
+ * Reading soft limit from specified resource.
+ */
+rlim_t
+proc_limitgetcur(proc_t p, int which, boolean_t to_lock_proc)
 {
-       struct  plimit * freelim = NULL;
-       struct  plimit * freeoldlim = NULL;
+       rlim_t rlim_cur;
 
-       proc_list_lock();
+       assert(p);
+       assert(which < RLIM_NLIMITS);
 
-       if (--p->p_limit->pl_refcnt == 0) { 
-               freelim = p->p_limit;
-               p->p_limit = NULL;
+       /*
+        * Serialize access to the process's plimit pointer for concurrent threads.
+        */
+       if (to_lock_proc) {
+               lck_mtx_assert(&p->p_mlock, LCK_MTX_ASSERT_NOTOWNED);
+               proc_lock(p);
        }
-       if ((exiting != 0) && (p->p_olimit != NULL) && (--p->p_olimit->pl_refcnt == 0)) {
-               freeoldlim =  p->p_olimit;
-               p->p_olimit = NULL;
+
+       rlim_cur = p->p_limit->pl_rlimit[which].rlim_cur;
+
+       if (to_lock_proc) {
+               proc_unlock(p);
        }
 
-       proc_list_unlock();
-       if (freelim != NULL)
-               FREE_ZONE(freelim, sizeof *p->p_limit, M_PLIMIT);
-       if (freeoldlim != NULL)
-               FREE_ZONE(freeoldlim, sizeof *p->p_olimit, M_PLIMIT);
+       return rlim_cur;
+}
+
+/*
+ * Writing soft limit to specified resource. This is an internal function
+ * used only by proc_exit and vfork_exit_internal to update RLIMIT_FSIZE in
+ * place without invoking setrlimit.
+ */
+void
+proc_limitsetcur_internal(proc_t p, int which, rlim_t value)
+{
+       struct rlimit rlim;
+
+       assert(p);
+       assertf(which == RLIMIT_FSIZE, "%s only supports RLIMIT_FSIZE\n", __FUNCTION__);
+
+
+       proc_lock(p);
+
+       /* Only one thread is able to change rlimit values at a time */
+       proc_limitblock(p);
+
+       /* Prepare an rlimit for proc_limitupdate */
+       rlim = p->p_limit->pl_rlimit[which];
+       rlim.rlim_cur = value;
+
+       /*
+        * proc_limitupdate will COW the current plimit and update specified the soft limit
+        * if the plimit is shared, otherwise it will update the soft limit in place.
+        */
+       proc_limitupdate(p, &rlim, (uint8_t)which);
+
+       /* Unblock other threads wishing to change plimit */
+       proc_limitunblock(p);
+
+       proc_unlock(p);
 }
 
+void
+proc_limitget(proc_t p, int which, struct rlimit * limp)
+{
+       assert(p);
+       assert(limp);
+       assert(which < RLIM_NLIMITS);
+
+       /* Protect writes to the process's plimit pointer issued by concurrent threads */
+       proc_lock(p);
+
+       limp->rlim_cur = p->p_limit->pl_rlimit[which].rlim_cur;
+       limp->rlim_max = p->p_limit->pl_rlimit[which].rlim_max;
+
+       proc_unlock(p);
+}
 
 void
 proc_limitfork(proc_t parent, proc_t child)
 {
-       proc_list_lock();
+       assert(parent && child);
+
+       proc_lock(parent);
+
+       /* Child proc inherits parent's plimit */
        child->p_limit = parent->p_limit;
-       child->p_limit->pl_refcnt++;
-       child->p_olimit = NULL;
-       proc_list_unlock();
+
+       /* Increment refcnt of the shared plimit */
+       os_ref_retain(&parent->p_limit->pl_refcnt);
+
+       proc_unlock(parent);
 }
 
 void
-proc_limitblock(proc_t p)
+proc_limitdrop(proc_t p)
 {
+       struct plimit *free_plim = NULL;
+       os_ref_count_t refcnt;
+
        proc_lock(p);
-       while (p->p_lflag & P_LLIMCHANGE) {
-               p->p_lflag |= P_LLIMWAIT;
-               msleep(&p->p_olimit, &p->p_mlock, 0, "proc_limitblock", NULL);
+
+       /* Drop the plimit reference before exiting the system */
+       refcnt = os_ref_release(&p->p_limit->pl_refcnt);
+       if (refcnt == 0) {
+               free_plim = p->p_limit;
        }
-       p->p_lflag |= P_LLIMCHANGE;
+
+       p->p_limit = NULL;
        proc_unlock(p);
 
+       /* We are the last user of this plimit, free it now. */
+       if (free_plim != NULL) {
+               zfree(plimit_zone, free_plim);
+       }
 }
 
+/*
+ * proc_limitblock/unblock are used to serialize access to plimit
+ * from concurrent threads within the same process.
+ * Callers must be holding the proc lock to enter, return with
+ * the proc lock locked
+ */
+void
+proc_limitblock(proc_t p)
+{
+       lck_mtx_assert(&p->p_mlock, LCK_MTX_ASSERT_OWNED);
+
+       while (p->p_lflag & P_LLIMCHANGE) {
+               p->p_lflag |= P_LLIMWAIT;
+               msleep(&p->p_limit, &p->p_mlock, 0, "proc_limitblock", NULL);
+       }
+       p->p_lflag |= P_LLIMCHANGE;
+}
 
+/*
+ * Callers must be holding the proc lock to enter, return with
+ * the proc lock locked
+ */
 void
 proc_limitunblock(proc_t p)
 {
-       proc_lock(p);
+       lck_mtx_assert(&p->p_mlock, LCK_MTX_ASSERT_OWNED);
+
        p->p_lflag &= ~P_LLIMCHANGE;
        if (p->p_lflag & P_LLIMWAIT) {
                p->p_lflag &= ~P_LLIMWAIT;
-               wakeup(&p->p_olimit);
+               wakeup(&p->p_limit);
        }
-       proc_unlock(p);
 }
 
-/* This is called behind serialization provided by proc_limitblock/unlbock */
-int
-proc_limitreplace(proc_t p)
+/*
+ * Change the rlimit values of process "p" to "rlim" for resource "which".
+ *
+ * If the current plimit is shared by multiple processes (refcnt > 1):
+ *    this routine replaces the process's original plimit with a new plimit,
+ *    update the requeted rlimit values, and free the original plimit if this
+ *    process is the last user.
+ *
+ * If the current plimit is used only by the calling process (refcnt == 1):
+ *    this routine updates the new rlimit values in place.
+ *
+ * Note: caller must be holding the proc lock before entering this routine.
+ * This routine allocates and frees kernel memory without holding the proc lock
+ * to minimize contention, and returns with the proc lock held.
+ */
+void
+proc_limitupdate(proc_t p, struct rlimit *rlim, uint8_t which)
 {
-       struct plimit *copy;
+       struct plimit  *copy_plim;
+       struct plimit  *free_plim;
+       os_ref_count_t refcnt;
 
+       assert(p && p->p_limit);
+       assert(rlim);
+       assert(which < RLIM_NLIMITS);
+       lck_mtx_assert(&p->p_mlock, LCK_MTX_ASSERT_OWNED);
 
-       proc_list_lock();
-
-       if (p->p_limit->pl_refcnt == 1) {
-               proc_list_unlock();
-               return(0);
+       /*
+        * If we are the only user of this plimit, don't bother allocating a plimit
+        * before making changes. Just modify the rlimit values in place.
+        */
+       refcnt = os_ref_get_count(&p->p_limit->pl_refcnt);
+       if (refcnt == 1) {
+               p->p_limit->pl_rlimit[which] = *rlim;
+               return;
        }
-               
-       proc_list_unlock();
 
-       MALLOC_ZONE(copy, struct plimit *,
-                       sizeof(struct plimit), M_PLIMIT, M_WAITOK);
-       if (copy == NULL) {
-               return(ENOMEM);
+       /*
+        * Allocating a new plimit for this process to apply the requested rlimit values.
+        * Not holding the lock on the original plimit gives other processes in the system
+        * a chance to access the plimit while we wait for memory below.
+        *
+        * The default zalloc should always succeed when WAIT flag.
+        */
+       proc_unlock(p);
+       copy_plim = zalloc(plimit_zone);
+
+       /* Copy the current p_limit */
+       proc_lock(p);
+       bcopy(p->p_limit->pl_rlimit, copy_plim->pl_rlimit, sizeof(struct rlimit) * RLIM_NLIMITS);
+
+       /*
+        * Drop our reference to the old plimit. Other processes sharing the old plimit could
+        * have exited the system when we wait for memory for the new plimit above, thus, we
+        * need to check the refcnt again and free the old plimit if this process is the last
+        * user. Also since we are holding the proc lock here, it's impossible for another threads
+        * to dereference the plimit, so it's safe to free the old plimit memory.
+        */
+       free_plim = NULL;
+       refcnt = os_ref_release(&p->p_limit->pl_refcnt);
+       if (refcnt == 0) {
+               free_plim = p->p_limit;
        }
+       /* Initialize the newly allocated plimit */
+       os_ref_init_count(&copy_plim->pl_refcnt, &rlimit_refgrp, 1);
+
+       /* Apply new rlimit values */
+       copy_plim->pl_rlimit[which] = *rlim;
+
+       /* All set, update the process's plimit pointer to the new plimit. */
+       p->p_limit = copy_plim;
+       proc_unlock(p);
 
-       proc_list_lock();
-       bcopy(p->p_limit->pl_rlimit, copy->pl_rlimit,
-           sizeof(struct rlimit) * RLIM_NLIMITS);
-       copy->pl_refcnt = 1;
-       /* hang on to reference to old till process exits */
-       p->p_olimit = p->p_limit;
-       p->p_limit = copy;
-       proc_list_unlock();
+       if (free_plim != NULL) {
+               zfree(plimit_zone, free_plim);
+       }
 
-       return(0);
+       /* Return with proc->p_mlock locked */
+       proc_lock(p);
 }
 
+static int
+iopolicysys_disk(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param);
+static int
+iopolicysys_vfs_hfs_case_sensitivity(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param);
+static int
+iopolicysys_vfs_atime_updates(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param);
+static int
+iopolicysys_vfs_materialize_dataless_files(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param);
+static int
+iopolicysys_vfs_statfs_no_data_volume(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param);
+static int
+iopolicysys_vfs_trigger_resolve(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param);
+static int
+iopolicysys_vfs_ignore_content_protection(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param);
+static int
+iopolicysys_vfs_ignore_node_permissions(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *ipo_param);
+static int
+iopolicysys_vfs_skip_mtime_update(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param);
 
 /*
  * iopolicysys
@@ -1326,207 +1632,1058 @@ proc_limitreplace(proc_t p)
  *
  */
 int
-iopolicysys(__unused struct proc *p, __unused struct iopolicysys_args *uap, __unused int32_t *retval)
+iopolicysys(struct proc *p, struct iopolicysys_args *uap, int32_t *retval)
 {
-       int     error = 0;
+       int     error = 0;
        struct _iopol_param_t iop_param;
-#if !CONFIG_EMBEDDED
-       int processwide = 0;
-#else /* !CONFIG_EMBEDDED */
-       thread_t thread = THREAD_NULL;
-       struct uthread  *ut = NULL;
-       int *policy;
-#endif /* !CONFIG_EMBEDDED */
-
-       if ((error = copyin(uap->arg, &iop_param, sizeof(iop_param))) != 0)
+
+       if ((error = copyin(uap->arg, &iop_param, sizeof(iop_param))) != 0) {
                goto out;
+       }
 
-       if (iop_param.iop_iotype != IOPOL_TYPE_DISK) {
+       switch (iop_param.iop_iotype) {
+       case IOPOL_TYPE_DISK:
+               error = iopolicysys_disk(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error == EIDRM) {
+                       *retval = -2;
+                       error = 0;
+               }
+               if (error) {
+                       goto out;
+               }
+               break;
+       case IOPOL_TYPE_VFS_HFS_CASE_SENSITIVITY:
+               error = iopolicysys_vfs_hfs_case_sensitivity(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error) {
+                       goto out;
+               }
+               break;
+       case IOPOL_TYPE_VFS_ATIME_UPDATES:
+               error = iopolicysys_vfs_atime_updates(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error) {
+                       goto out;
+               }
+               break;
+       case IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES:
+               error = iopolicysys_vfs_materialize_dataless_files(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error) {
+                       goto out;
+               }
+               break;
+       case IOPOL_TYPE_VFS_STATFS_NO_DATA_VOLUME:
+               error = iopolicysys_vfs_statfs_no_data_volume(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error) {
+                       goto out;
+               }
+               break;
+       case IOPOL_TYPE_VFS_TRIGGER_RESOLVE:
+               error = iopolicysys_vfs_trigger_resolve(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error) {
+                       goto out;
+               }
+               break;
+       case IOPOL_TYPE_VFS_IGNORE_CONTENT_PROTECTION:
+               error = iopolicysys_vfs_ignore_content_protection(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error) {
+                       goto out;
+               }
+               break;
+       case IOPOL_TYPE_VFS_IGNORE_PERMISSIONS:
+               error = iopolicysys_vfs_ignore_node_permissions(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error) {
+                       goto out;
+               }
+               break;
+       case IOPOL_TYPE_VFS_SKIP_MTIME_UPDATE:
+               error = iopolicysys_vfs_skip_mtime_update(p, uap->cmd, iop_param.iop_scope, iop_param.iop_policy, &iop_param);
+               if (error) {
+                       goto out;
+               }
+               break;
+       default:
                error = EINVAL;
                goto out;
        }
 
-#if !CONFIG_EMBEDDED
-       switch (iop_param.iop_scope) {
+       /* Individual iotype handlers are expected to update iop_param, if requested with a GET command */
+       if (uap->cmd == IOPOL_CMD_GET) {
+               error = copyout((caddr_t)&iop_param, uap->arg, sizeof(iop_param));
+               if (error) {
+                       goto out;
+               }
+       }
+
+out:
+       return error;
+}
+
+static int
+iopolicysys_disk(struct proc *p __unused, int cmd, int scope, int policy, struct _iopol_param_t *iop_param)
+{
+       int                     error = 0;
+       thread_t        thread;
+       int                     policy_flavor;
+
+       /* Validate scope */
+       switch (scope) {
        case IOPOL_SCOPE_PROCESS:
-               processwide = 1;
+               thread = THREAD_NULL;
+               policy_flavor = TASK_POLICY_IOPOL;
                break;
+
        case IOPOL_SCOPE_THREAD:
-               processwide = 0;
+               thread = current_thread();
+               policy_flavor = TASK_POLICY_IOPOL;
+
+               /* Not allowed to combine QoS and (non-PASSIVE) IO policy, doing so strips the QoS */
+               if (cmd == IOPOL_CMD_SET && thread_has_qos_policy(thread)) {
+                       switch (policy) {
+                       case IOPOL_DEFAULT:
+                       case IOPOL_PASSIVE:
+                               break;
+                       case IOPOL_UTILITY:
+                       case IOPOL_THROTTLE:
+                       case IOPOL_IMPORTANT:
+                       case IOPOL_STANDARD:
+                               if (!thread_is_static_param(thread)) {
+                                       thread_remove_qos_policy(thread);
+                                       /*
+                                        * This is not an error case, this is to return a marker to user-space that
+                                        * we stripped the thread of its QoS class.
+                                        */
+                                       error = EIDRM;
+                                       break;
+                               }
+                               OS_FALLTHROUGH;
+                       default:
+                               error = EINVAL;
+                               goto out;
+                       }
+               }
                break;
+
+       case IOPOL_SCOPE_DARWIN_BG:
+#if !defined(XNU_TARGET_OS_OSX)
+               /* We don't want this on platforms outside of macOS as BG is always IOPOL_THROTTLE */
+               error = ENOTSUP;
+               goto out;
+#else /* !defined(XNU_TARGET_OS_OSX) */
+               thread = THREAD_NULL;
+               policy_flavor = TASK_POLICY_DARWIN_BG_IOPOL;
+               break;
+#endif /* !defined(XNU_TARGET_OS_OSX) */
+
        default:
                error = EINVAL;
                goto out;
        }
-               
-       switch(uap->cmd) {
-       case IOPOL_CMD_SET:
-               switch (iop_param.iop_policy) {
+
+       /* Validate policy */
+       if (cmd == IOPOL_CMD_SET) {
+               switch (policy) {
                case IOPOL_DEFAULT:
-               case IOPOL_NORMAL:
+                       if (scope == IOPOL_SCOPE_DARWIN_BG) {
+                               /* the current default BG throttle level is UTILITY */
+                               policy = IOPOL_UTILITY;
+                       } else {
+                               policy = IOPOL_IMPORTANT;
+                       }
+                       break;
+               case IOPOL_UTILITY:
+               /* fall-through */
                case IOPOL_THROTTLE:
+                       /* These levels are OK */
+                       break;
+               case IOPOL_IMPORTANT:
+               /* fall-through */
+               case IOPOL_STANDARD:
+               /* fall-through */
                case IOPOL_PASSIVE:
-                       if(processwide != 0)
-                               proc_apply_task_diskacc(current_task(), iop_param.iop_policy);
-                       else
-                               proc_apply_thread_selfdiskacc(iop_param.iop_policy);
-                               
+                       if (scope == IOPOL_SCOPE_DARWIN_BG) {
+                               /* These levels are invalid for BG */
+                               error = EINVAL;
+                               goto out;
+                       } else {
+                               /* OK for other scopes */
+                       }
                        break;
                default:
                        error = EINVAL;
                        goto out;
                }
+       }
+
+       /* Perform command */
+       switch (cmd) {
+       case IOPOL_CMD_SET:
+               if (thread != THREAD_NULL) {
+                       proc_set_thread_policy(thread, TASK_POLICY_INTERNAL, policy_flavor, policy);
+               } else {
+                       proc_set_task_policy(current_task(), TASK_POLICY_INTERNAL, policy_flavor, policy);
+               }
                break;
-       
        case IOPOL_CMD_GET:
-               if(processwide != 0)
-                       iop_param.iop_policy = proc_get_task_disacc(current_task());
-               else
-                       iop_param.iop_policy = proc_get_thread_selfdiskacc();
-                       
-               error = copyout((caddr_t)&iop_param, uap->arg, sizeof(iop_param));
-
+               if (thread != THREAD_NULL) {
+                       policy = proc_get_thread_policy(thread, TASK_POLICY_INTERNAL, policy_flavor);
+               } else {
+                       policy = proc_get_task_policy(current_task(), TASK_POLICY_INTERNAL, policy_flavor);
+               }
+               iop_param->iop_policy = policy;
                break;
        default:
-               error = EINVAL; // unknown command
+               error = EINVAL;         /* unknown command */
                break;
        }
 
-#else /* !CONFIG_EMBEDDED */
-       switch (iop_param.iop_scope) {
+out:
+       return error;
+}
+
+static int
+iopolicysys_vfs_hfs_case_sensitivity(struct proc *p, int cmd, int scope, int policy, struct _iopol_param_t *iop_param)
+{
+       int                     error = 0;
+
+       /* Validate scope */
+       switch (scope) {
        case IOPOL_SCOPE_PROCESS:
-               policy = &p->p_iopol_disk;
+               /* Only process OK */
+               break;
+       default:
+               error = EINVAL;
+               goto out;
+       }
+
+       /* Validate policy */
+       if (cmd == IOPOL_CMD_SET) {
+               switch (policy) {
+               case IOPOL_VFS_HFS_CASE_SENSITIVITY_DEFAULT:
+               /* fall-through */
+               case IOPOL_VFS_HFS_CASE_SENSITIVITY_FORCE_CASE_SENSITIVE:
+                       /* These policies are OK */
+                       break;
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
+       }
+
+       /* Perform command */
+       switch (cmd) {
+       case IOPOL_CMD_SET:
+               if (0 == kauth_cred_issuser(kauth_cred_get())) {
+                       /* If it's a non-root process, it needs to have the entitlement to set the policy */
+                       boolean_t entitled = FALSE;
+                       entitled = IOTaskHasEntitlement(current_task(), "com.apple.private.iopol.case_sensitivity");
+                       if (!entitled) {
+                               error = EPERM;
+                               goto out;
+                       }
+               }
+
+               switch (policy) {
+               case IOPOL_VFS_HFS_CASE_SENSITIVITY_DEFAULT:
+                       OSBitAndAtomic16(~((uint32_t)P_VFS_IOPOLICY_FORCE_HFS_CASE_SENSITIVITY), &p->p_vfs_iopolicy);
+                       break;
+               case IOPOL_VFS_HFS_CASE_SENSITIVITY_FORCE_CASE_SENSITIVE:
+                       OSBitOrAtomic16((uint32_t)P_VFS_IOPOLICY_FORCE_HFS_CASE_SENSITIVITY, &p->p_vfs_iopolicy);
+                       break;
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
+
                break;
+       case IOPOL_CMD_GET:
+               iop_param->iop_policy = (p->p_vfs_iopolicy & P_VFS_IOPOLICY_FORCE_HFS_CASE_SENSITIVITY)
+                   ? IOPOL_VFS_HFS_CASE_SENSITIVITY_FORCE_CASE_SENSITIVE
+                   : IOPOL_VFS_HFS_CASE_SENSITIVITY_DEFAULT;
+               break;
+       default:
+               error = EINVAL;         /* unknown command */
+               break;
+       }
+
+out:
+       return error;
+}
+
+static inline int
+get_thread_atime_policy(struct uthread *ut)
+{
+       return (ut->uu_flag & UT_ATIME_UPDATE) ? IOPOL_ATIME_UPDATES_OFF : IOPOL_ATIME_UPDATES_DEFAULT;
+}
+
+static inline void
+set_thread_atime_policy(struct uthread *ut, int policy)
+{
+       if (policy == IOPOL_ATIME_UPDATES_OFF) {
+               ut->uu_flag |= UT_ATIME_UPDATE;
+       } else {
+               ut->uu_flag &= ~UT_ATIME_UPDATE;
+       }
+}
+
+static inline void
+set_task_atime_policy(struct proc *p, int policy)
+{
+       if (policy == IOPOL_ATIME_UPDATES_OFF) {
+               OSBitOrAtomic16((uint16_t)P_VFS_IOPOLICY_ATIME_UPDATES, &p->p_vfs_iopolicy);
+       } else {
+               OSBitAndAtomic16(~((uint16_t)P_VFS_IOPOLICY_ATIME_UPDATES), &p->p_vfs_iopolicy);
+       }
+}
+
+static inline int
+get_task_atime_policy(struct proc *p)
+{
+       return (p->p_vfs_iopolicy & P_VFS_IOPOLICY_ATIME_UPDATES) ? IOPOL_ATIME_UPDATES_OFF : IOPOL_ATIME_UPDATES_DEFAULT;
+}
+
+static int
+iopolicysys_vfs_atime_updates(struct proc *p __unused, int cmd, int scope, int policy, struct _iopol_param_t *iop_param)
+{
+       int                     error = 0;
+       thread_t                thread;
+
+       /* Validate scope */
+       switch (scope) {
        case IOPOL_SCOPE_THREAD:
                thread = current_thread();
-               ut = get_bsdthread_info(thread);
-               policy = &ut->uu_iopol_disk;
+               break;
+       case IOPOL_SCOPE_PROCESS:
+               thread = THREAD_NULL;
                break;
        default:
                error = EINVAL;
                goto out;
        }
-               
-       switch(uap->cmd) {
+
+       /* Validate policy */
+       if (cmd == IOPOL_CMD_SET) {
+               switch (policy) {
+               case IOPOL_ATIME_UPDATES_DEFAULT:
+               case IOPOL_ATIME_UPDATES_OFF:
+                       break;
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
+       }
+
+       /* Perform command */
+       switch (cmd) {
        case IOPOL_CMD_SET:
-               switch (iop_param.iop_policy) {
-               case IOPOL_DEFAULT:
-               case IOPOL_NORMAL:
-               case IOPOL_THROTTLE:
-               case IOPOL_PASSIVE:
-                       proc_lock(p);
-                       *policy = iop_param.iop_policy;
-                       proc_unlock(p);
+               if (thread != THREAD_NULL) {
+                       set_thread_atime_policy(get_bsdthread_info(thread), policy);
+               } else {
+                       set_task_atime_policy(p, policy);
+               }
+               break;
+       case IOPOL_CMD_GET:
+               if (thread != THREAD_NULL) {
+                       policy = get_thread_atime_policy(get_bsdthread_info(thread));
+               } else {
+                       policy = get_task_atime_policy(p);
+               }
+               iop_param->iop_policy = policy;
+               break;
+       default:
+               error = EINVAL;         /* unknown command */
+               break;
+       }
+
+out:
+       return error;
+}
+
+static inline int
+get_thread_materialize_policy(struct uthread *ut)
+{
+       if (ut->uu_flag & UT_NSPACE_NODATALESSFAULTS) {
+               return IOPOL_MATERIALIZE_DATALESS_FILES_OFF;
+       } else if (ut->uu_flag & UT_NSPACE_FORCEDATALESSFAULTS) {
+               return IOPOL_MATERIALIZE_DATALESS_FILES_ON;
+       }
+       /* Default thread behavior is "inherit process behavior". */
+       return IOPOL_MATERIALIZE_DATALESS_FILES_DEFAULT;
+}
+
+static inline void
+set_thread_materialize_policy(struct uthread *ut, int policy)
+{
+       if (policy == IOPOL_MATERIALIZE_DATALESS_FILES_OFF) {
+               ut->uu_flag &= ~UT_NSPACE_FORCEDATALESSFAULTS;
+               ut->uu_flag |= UT_NSPACE_NODATALESSFAULTS;
+       } else if (policy == IOPOL_MATERIALIZE_DATALESS_FILES_ON) {
+               ut->uu_flag &= ~UT_NSPACE_NODATALESSFAULTS;
+               ut->uu_flag |= UT_NSPACE_FORCEDATALESSFAULTS;
+       } else {
+               ut->uu_flag &= ~(UT_NSPACE_NODATALESSFAULTS | UT_NSPACE_FORCEDATALESSFAULTS);
+       }
+}
+
+static inline void
+set_proc_materialize_policy(struct proc *p, int policy)
+{
+       if (policy == IOPOL_MATERIALIZE_DATALESS_FILES_DEFAULT) {
+               /*
+                * Caller has specified "use the default policy".
+                * The default policy is to NOT materialize dataless
+                * files.
+                */
+               policy = IOPOL_MATERIALIZE_DATALESS_FILES_OFF;
+       }
+       if (policy == IOPOL_MATERIALIZE_DATALESS_FILES_ON) {
+               OSBitOrAtomic16((uint16_t)P_VFS_IOPOLICY_MATERIALIZE_DATALESS_FILES, &p->p_vfs_iopolicy);
+       } else {
+               OSBitAndAtomic16(~((uint16_t)P_VFS_IOPOLICY_MATERIALIZE_DATALESS_FILES), &p->p_vfs_iopolicy);
+       }
+}
+
+static int
+get_proc_materialize_policy(struct proc *p)
+{
+       return (p->p_vfs_iopolicy & P_VFS_IOPOLICY_MATERIALIZE_DATALESS_FILES) ? IOPOL_MATERIALIZE_DATALESS_FILES_ON : IOPOL_MATERIALIZE_DATALESS_FILES_OFF;
+}
+
+static int
+iopolicysys_vfs_materialize_dataless_files(struct proc *p __unused, int cmd, int scope, int policy, struct _iopol_param_t *iop_param)
+{
+       int                     error = 0;
+       thread_t                thread;
+
+       /* Validate scope */
+       switch (scope) {
+       case IOPOL_SCOPE_THREAD:
+               thread = current_thread();
+               break;
+       case IOPOL_SCOPE_PROCESS:
+               thread = THREAD_NULL;
+               break;
+       default:
+               error = EINVAL;
+               goto out;
+       }
+
+       /* Validate policy */
+       if (cmd == IOPOL_CMD_SET) {
+               switch (policy) {
+               case IOPOL_MATERIALIZE_DATALESS_FILES_DEFAULT:
+               case IOPOL_MATERIALIZE_DATALESS_FILES_OFF:
+               case IOPOL_MATERIALIZE_DATALESS_FILES_ON:
                        break;
                default:
                        error = EINVAL;
                        goto out;
                }
+       }
+
+       /* Perform command */
+       switch (cmd) {
+       case IOPOL_CMD_SET:
+               if (thread != THREAD_NULL) {
+                       set_thread_materialize_policy(get_bsdthread_info(thread), policy);
+               } else {
+                       set_proc_materialize_policy(p, policy);
+               }
                break;
        case IOPOL_CMD_GET:
-               switch (*policy) {
-               case IOPOL_DEFAULT:
-               case IOPOL_NORMAL:
-               case IOPOL_THROTTLE:
-               case IOPOL_PASSIVE:
-                       iop_param.iop_policy = *policy;
+               if (thread != THREAD_NULL) {
+                       policy = get_thread_materialize_policy(get_bsdthread_info(thread));
+               } else {
+                       policy = get_proc_materialize_policy(p);
+               }
+               iop_param->iop_policy = policy;
+               break;
+       default:
+               error = EINVAL;         /* unknown command */
+               break;
+       }
+
+out:
+       return error;
+}
+
+static int
+iopolicysys_vfs_statfs_no_data_volume(struct proc *p __unused, int cmd,
+    int scope, int policy, struct _iopol_param_t *iop_param)
+{
+       int error = 0;
+
+       /* Validate scope */
+       switch (scope) {
+       case IOPOL_SCOPE_PROCESS:
+               /* Only process OK */
+               break;
+       default:
+               error = EINVAL;
+               goto out;
+       }
+
+       /* Validate policy */
+       if (cmd == IOPOL_CMD_SET) {
+               switch (policy) {
+               case IOPOL_VFS_STATFS_NO_DATA_VOLUME_DEFAULT:
+               /* fall-through */
+               case IOPOL_VFS_STATFS_FORCE_NO_DATA_VOLUME:
+                       /* These policies are OK */
                        break;
-               default: // in-kernel 
-                       // this should never happen
-                       printf("%s: unknown I/O policy %d\n", __func__, *policy);
-                       // restore to default value
-                       *policy = IOPOL_DEFAULT;
-                       iop_param.iop_policy = *policy;
-               }
-               
-               error = copyout((caddr_t)&iop_param, uap->arg, sizeof(iop_param));
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
+       }
+
+       /* Perform command */
+       switch (cmd) {
+       case IOPOL_CMD_SET:
+               if (0 == kauth_cred_issuser(kauth_cred_get())) {
+                       /* If it's a non-root process, it needs to have the entitlement to set the policy */
+                       boolean_t entitled = FALSE;
+                       entitled = IOTaskHasEntitlement(current_task(), "com.apple.private.iopol.case_sensitivity");
+                       if (!entitled) {
+                               error = EPERM;
+                               goto out;
+                       }
+               }
+
+               switch (policy) {
+               case IOPOL_VFS_STATFS_NO_DATA_VOLUME_DEFAULT:
+                       OSBitAndAtomic16(~((uint32_t)P_VFS_IOPOLICY_STATFS_NO_DATA_VOLUME), &p->p_vfs_iopolicy);
+                       break;
+               case IOPOL_VFS_STATFS_FORCE_NO_DATA_VOLUME:
+                       OSBitOrAtomic16((uint32_t)P_VFS_IOPOLICY_STATFS_NO_DATA_VOLUME, &p->p_vfs_iopolicy);
+                       break;
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
+
+               break;
+       case IOPOL_CMD_GET:
+               iop_param->iop_policy = (p->p_vfs_iopolicy & P_VFS_IOPOLICY_STATFS_NO_DATA_VOLUME)
+                   ? IOPOL_VFS_STATFS_FORCE_NO_DATA_VOLUME
+                   : IOPOL_VFS_STATFS_NO_DATA_VOLUME_DEFAULT;
                break;
        default:
-               error = EINVAL; // unknown command
+               error = EINVAL;         /* unknown command */
                break;
        }
 
-#endif /* !CONFIG_EMBEDDED */
 out:
-       *retval = error;
-       return (error);
+       return error;
 }
 
+static int
+iopolicysys_vfs_trigger_resolve(struct proc *p __unused, int cmd,
+    int scope, int policy, struct _iopol_param_t *iop_param)
+{
+       int error = 0;
+
+       /* Validate scope */
+       switch (scope) {
+       case IOPOL_SCOPE_PROCESS:
+               /* Only process OK */
+               break;
+       default:
+               error = EINVAL;
+               goto out;
+       }
+
+       /* Validate policy */
+       if (cmd == IOPOL_CMD_SET) {
+               switch (policy) {
+               case IOPOL_VFS_TRIGGER_RESOLVE_DEFAULT:
+               /* fall-through */
+               case IOPOL_VFS_TRIGGER_RESOLVE_OFF:
+                       /* These policies are OK */
+                       break;
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
+       }
+
+       /* Perform command */
+       switch (cmd) {
+       case IOPOL_CMD_SET:
+               switch (policy) {
+               case IOPOL_VFS_TRIGGER_RESOLVE_DEFAULT:
+                       OSBitAndAtomic16(~((uint32_t)P_VFS_IOPOLICY_TRIGGER_RESOLVE_DISABLE), &p->p_vfs_iopolicy);
+                       break;
+               case IOPOL_VFS_TRIGGER_RESOLVE_OFF:
+                       OSBitOrAtomic16((uint32_t)P_VFS_IOPOLICY_TRIGGER_RESOLVE_DISABLE, &p->p_vfs_iopolicy);
+                       break;
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
+
+               break;
+       case IOPOL_CMD_GET:
+               iop_param->iop_policy = (p->p_vfs_iopolicy & P_VFS_IOPOLICY_TRIGGER_RESOLVE_DISABLE)
+                   ? IOPOL_VFS_TRIGGER_RESOLVE_OFF
+                   : IOPOL_VFS_TRIGGER_RESOLVE_DEFAULT;
+               break;
+       default:
+               error = EINVAL;         /* unknown command */
+               break;
+       }
 
-boolean_t thread_is_io_throttled(void);
+out:
+       return error;
+}
 
-boolean_t
-thread_is_io_throttled(void) 
+static int
+iopolicysys_vfs_ignore_content_protection(struct proc *p, int cmd, int scope,
+    int policy, struct _iopol_param_t *iop_param)
 {
+       int error = 0;
+
+       /* Validate scope */
+       switch (scope) {
+       case IOPOL_SCOPE_PROCESS:
+               /* Only process OK */
+               break;
+       default:
+               error = EINVAL;
+               goto out;
+       }
+
+       /* Validate policy */
+       if (cmd == IOPOL_CMD_SET) {
+               switch (policy) {
+               case IOPOL_VFS_CONTENT_PROTECTION_DEFAULT:
+                       OS_FALLTHROUGH;
+               case IOPOL_VFS_CONTENT_PROTECTION_IGNORE:
+                       /* These policies are OK */
+                       break;
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
+       }
+
+       /* Perform command */
+       switch (cmd) {
+       case IOPOL_CMD_SET:
+               if (0 == kauth_cred_issuser(kauth_cred_get())) {
+                       /* If it's a non-root process, it needs to have the entitlement to set the policy */
+                       boolean_t entitled = FALSE;
+                       entitled = IOTaskHasEntitlement(current_task(), "com.apple.private.iopol.case_sensitivity");
+                       if (!entitled) {
+                               error = EPERM;
+                               goto out;
+                       }
+               }
+
+               switch (policy) {
+               case IOPOL_VFS_CONTENT_PROTECTION_DEFAULT:
+                       os_atomic_andnot(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_IGNORE_CONTENT_PROTECTION, relaxed);
+                       break;
+               case IOPOL_VFS_CONTENT_PROTECTION_IGNORE:
+                       os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_IGNORE_CONTENT_PROTECTION, relaxed);
+                       break;
+               default:
+                       error = EINVAL;
+                       goto out;
+               }
 
-#if !CONFIG_EMBEDDED
+               break;
+       case IOPOL_CMD_GET:
+               iop_param->iop_policy = (os_atomic_load(&p->p_vfs_iopolicy, relaxed) & P_VFS_IOPOLICY_IGNORE_CONTENT_PROTECTION)
+                   ? IOPOL_VFS_CONTENT_PROTECTION_IGNORE
+                   : IOPOL_VFS_CONTENT_PROTECTION_DEFAULT;
+               break;
+       default:
+               error = EINVAL;         /* unknown command */
+               break;
+       }
 
-       return(proc_get_task_selfdiskacc() == IOPOL_THROTTLE);
-               
-#else /* !CONFIG_EMBEDDED */
-       int     policy;
-       struct uthread  *ut;
+out:
+       return error;
+}
 
-       ut = get_bsdthread_info(current_thread());
+#define AUTHORIZED_ACCESS_ENTITLEMENT \
+       "com.apple.private.vfs.authorized-access"
+int
+iopolicysys_vfs_ignore_node_permissions(struct proc *p, int cmd, int scope,
+    int policy, __unused struct _iopol_param_t *iop_param)
+{
+       int error = EINVAL;
 
-       if(ut){
-               policy = current_proc()->p_iopol_disk;
+       switch (scope) {
+       case IOPOL_SCOPE_PROCESS:
+               break;
+       default:
+               goto out;
+       }
 
-               if (ut->uu_iopol_disk != IOPOL_DEFAULT)
-                       policy = ut->uu_iopol_disk;
+       switch (cmd) {
+       case IOPOL_CMD_GET:
+               policy = os_atomic_load(&p->p_vfs_iopolicy, relaxed) & P_VFS_IOPOLICY_IGNORE_NODE_PERMISSIONS ?
+                   IOPOL_VFS_IGNORE_PERMISSIONS_ON : IOPOL_VFS_IGNORE_PERMISSIONS_OFF;
+               iop_param->iop_policy = policy;
+               goto out_ok;
+       case IOPOL_CMD_SET:
+               /* SET is handled after the switch */
+               break;
+       default:
+               goto out;
+       }
+
+       if (!IOTaskHasEntitlement(current_task(), AUTHORIZED_ACCESS_ENTITLEMENT)) {
+               error = EPERM;
+               goto out;
+       }
 
-               if (policy == IOPOL_THROTTLE)
-                       return TRUE;
+       switch (policy) {
+       case IOPOL_VFS_IGNORE_PERMISSIONS_OFF:
+               os_atomic_andnot(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_IGNORE_NODE_PERMISSIONS, relaxed);
+               break;
+       case IOPOL_VFS_IGNORE_PERMISSIONS_ON:
+               os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_IGNORE_NODE_PERMISSIONS, relaxed);
+               break;
+       default:
+               break;
        }
-       return FALSE;
-#endif /* !CONFIG_EMBEDDED */
+
+out_ok:
+       error = 0;
+out:
+       return error;
 }
 
+#define SKIP_MTIME_UPDATE_ENTITLEMENT \
+       "com.apple.private.vfs.skip-mtime-updates"
+int
+iopolicysys_vfs_skip_mtime_update(struct proc *p, int cmd, int scope,
+    int policy, __unused struct _iopol_param_t *iop_param)
+{
+       int error = EINVAL;
+
+       switch (scope) {
+       case IOPOL_SCOPE_PROCESS:
+               break;
+       default:
+               goto out;
+       }
+
+       switch (cmd) {
+       case IOPOL_CMD_GET:
+               policy = os_atomic_load(&p->p_vfs_iopolicy, relaxed) & P_VFS_IOPOLICY_SKIP_MTIME_UPDATE ?
+                   IOPOL_VFS_SKIP_MTIME_UPDATE_ON : IOPOL_VFS_SKIP_MTIME_UPDATE_OFF;
+               iop_param->iop_policy = policy;
+               goto out_ok;
+       case IOPOL_CMD_SET:
+               break;
+       default:
+               break;
+       }
+
+       if (!IOTaskHasEntitlement(current_task(), SKIP_MTIME_UPDATE_ENTITLEMENT)) {
+               error = EPERM;
+               goto out;
+       }
+
+       switch (policy) {
+       case IOPOL_VFS_SKIP_MTIME_UPDATE_OFF:
+               os_atomic_andnot(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_SKIP_MTIME_UPDATE, relaxed);
+               break;
+       case IOPOL_VFS_SKIP_MTIME_UPDATE_ON:
+               os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_SKIP_MTIME_UPDATE, relaxed);
+               break;
+       default:
+               break;
+       }
+
+out_ok:
+       error = 0;
+out:
+       return error;
+}
+/* BSD call back function for task_policy networking changes */
 void
-proc_apply_task_networkbg(void * bsd_info)
+proc_apply_task_networkbg(void * bsd_info, thread_t thread)
 {
-       proc_t p = PROC_NULL;
-       proc_t curp = (proc_t)bsd_info;
-       pid_t pid;
+       assert(bsd_info != PROC_NULL);
+
+       pid_t pid = proc_pid((proc_t)bsd_info);
+
+       proc_t p = proc_find(pid);
 
-       pid = curp->p_pid;
-       p = proc_find(pid);
        if (p != PROC_NULL) {
-               do_background_socket(p, NULL, PRIO_DARWIN_BG);
+               assert(p == (proc_t)bsd_info);
+
+               do_background_socket(p, thread);
                proc_rele(p);
        }
 }
 
 void
-proc_restore_task_networkbg(void * bsd_info)
+gather_rusage_info(proc_t p, rusage_info_current *ru, int flavor)
 {
-       proc_t p = PROC_NULL;
-       proc_t curp = (proc_t)bsd_info;
-       pid_t pid;
+       struct rusage_info_child *ri_child;
+
+       assert(p->p_stats != NULL);
+       memset(ru, 0, sizeof(*ru));
+       switch (flavor) {
+       case RUSAGE_INFO_V5:
+#if !XNU_TARGET_OS_OSX && __has_feature(ptrauth_calls)
+               if (vm_shared_region_is_reslide(p->task)) {
+                       ru->ri_flags |= RU_PROC_RUNS_RESLIDE;
+               }
+#endif /* !XNU_TARGET_OS_OSX && __has_feature(ptrauth_calls) */
+               OS_FALLTHROUGH;
+       case RUSAGE_INFO_V4:
+               ru->ri_logical_writes = get_task_logical_writes(p->task, FALSE);
+               ru->ri_lifetime_max_phys_footprint = get_task_phys_footprint_lifetime_max(p->task);
+#if CONFIG_LEDGER_INTERVAL_MAX
+               ru->ri_interval_max_phys_footprint = get_task_phys_footprint_interval_max(p->task, FALSE);
+#endif
+               fill_task_monotonic_rusage(p->task, ru);
+               OS_FALLTHROUGH;
 
-       pid = curp->p_pid;
-       p = proc_find(pid);
-       if (p != PROC_NULL) {
-               do_background_socket(p, NULL, 0);
-               proc_rele(p);
+       case RUSAGE_INFO_V3:
+               fill_task_qos_rusage(p->task, ru);
+               fill_task_billed_usage(p->task, ru);
+               OS_FALLTHROUGH;
+
+       case RUSAGE_INFO_V2:
+               fill_task_io_rusage(p->task, ru);
+               OS_FALLTHROUGH;
+
+       case RUSAGE_INFO_V1:
+               /*
+                * p->p_stats->ri_child statistics are protected under proc lock.
+                */
+               proc_lock(p);
+
+               ri_child = &(p->p_stats->ri_child);
+               ru->ri_child_user_time = ri_child->ri_child_user_time;
+               ru->ri_child_system_time = ri_child->ri_child_system_time;
+               ru->ri_child_pkg_idle_wkups = ri_child->ri_child_pkg_idle_wkups;
+               ru->ri_child_interrupt_wkups = ri_child->ri_child_interrupt_wkups;
+               ru->ri_child_pageins = ri_child->ri_child_pageins;
+               ru->ri_child_elapsed_abstime = ri_child->ri_child_elapsed_abstime;
+
+               proc_unlock(p);
+               OS_FALLTHROUGH;
+
+       case RUSAGE_INFO_V0:
+               proc_getexecutableuuid(p, (unsigned char *)&ru->ri_uuid, sizeof(ru->ri_uuid));
+               fill_task_rusage(p->task, ru);
+               ru->ri_proc_start_abstime = p->p_stats->ps_start;
+       }
+}
+
+int
+proc_get_rusage(proc_t p, int flavor, user_addr_t buffer, __unused int is_zombie)
+{
+       rusage_info_current ri_current = {};
+
+       int error = 0;
+       size_t size = 0;
+
+       switch (flavor) {
+       case RUSAGE_INFO_V0:
+               size = sizeof(struct rusage_info_v0);
+               break;
+
+       case RUSAGE_INFO_V1:
+               size = sizeof(struct rusage_info_v1);
+               break;
+
+       case RUSAGE_INFO_V2:
+               size = sizeof(struct rusage_info_v2);
+               break;
+
+       case RUSAGE_INFO_V3:
+               size = sizeof(struct rusage_info_v3);
+               break;
+
+       case RUSAGE_INFO_V4:
+               size = sizeof(struct rusage_info_v4);
+               break;
+
+       case RUSAGE_INFO_V5:
+               size = sizeof(struct rusage_info_v5);
+               break;
+       default:
+               return EINVAL;
+       }
+
+       if (size == 0) {
+               return EINVAL;
        }
 
+       /*
+        * If task is still alive, collect info from the live task itself.
+        * Otherwise, look to the cached info in the zombie proc.
+        */
+       if (p->p_ru == NULL) {
+               gather_rusage_info(p, &ri_current, flavor);
+               ri_current.ri_proc_exit_abstime = 0;
+               error = copyout(&ri_current, buffer, size);
+       } else {
+               ri_current = p->p_ru->ri;
+               error = copyout(&p->p_ru->ri, buffer, size);
+       }
+
+       return error;
 }
 
-void
-proc_set_task_networkbg(void * bsdinfo, int setbg)
+static int
+mach_to_bsd_rv(int mach_rv)
 {
-       if (setbg != 0)
-               proc_apply_task_networkbg(bsdinfo);
-       else
-               proc_restore_task_networkbg(bsdinfo);
+       int bsd_rv = 0;
+
+       switch (mach_rv) {
+       case KERN_SUCCESS:
+               bsd_rv = 0;
+               break;
+       case KERN_INVALID_ARGUMENT:
+               bsd_rv = EINVAL;
+               break;
+       default:
+               panic("unknown error %#x", mach_rv);
+       }
+
+       return bsd_rv;
 }
 
-void
-proc_apply_task_networkbg_internal(proc_t p)
+/*
+ * Resource limit controls
+ *
+ * uap->flavor available flavors:
+ *
+ *     RLIMIT_WAKEUPS_MONITOR
+ *     RLIMIT_CPU_USAGE_MONITOR
+ *     RLIMIT_THREAD_CPULIMITS
+ *     RLIMIT_FOOTPRINT_INTERVAL
+ */
+int
+proc_rlimit_control(__unused struct proc *p, struct proc_rlimit_control_args *uap, __unused int32_t *retval)
 {
-       if (p != PROC_NULL) {
-               do_background_socket(p, NULL, PRIO_DARWIN_BG);
+       proc_t  targetp;
+       int     error = 0;
+       struct  proc_rlimit_control_wakeupmon wakeupmon_args;
+       uint32_t cpumon_flags;
+       uint32_t cpulimits_flags;
+       kauth_cred_t my_cred, target_cred;
+#if CONFIG_LEDGER_INTERVAL_MAX
+       uint32_t footprint_interval_flags;
+       uint64_t interval_max_footprint;
+#endif /* CONFIG_LEDGER_INTERVAL_MAX */
+
+       /* -1 implicitly means our own process (perhaps even the current thread for per-thread attributes) */
+       if (uap->pid == -1) {
+               targetp = proc_self();
+       } else {
+               targetp = proc_find(uap->pid);
+       }
+
+       /* proc_self() can return NULL for an exiting process */
+       if (targetp == PROC_NULL) {
+               return ESRCH;
+       }
+
+       my_cred = kauth_cred_get();
+       target_cred = kauth_cred_proc_ref(targetp);
+
+       if (!kauth_cred_issuser(my_cred) && kauth_cred_getruid(my_cred) &&
+           kauth_cred_getuid(my_cred) != kauth_cred_getuid(target_cred) &&
+           kauth_cred_getruid(my_cred) != kauth_cred_getuid(target_cred)) {
+               proc_rele(targetp);
+               kauth_cred_unref(&target_cred);
+               return EACCES;
        }
+
+       switch (uap->flavor) {
+       case RLIMIT_WAKEUPS_MONITOR:
+               if ((error = copyin(uap->arg, &wakeupmon_args, sizeof(wakeupmon_args))) != 0) {
+                       break;
+               }
+               if ((error = mach_to_bsd_rv(task_wakeups_monitor_ctl(targetp->task, &wakeupmon_args.wm_flags,
+                   &wakeupmon_args.wm_rate))) != 0) {
+                       break;
+               }
+               error = copyout(&wakeupmon_args, uap->arg, sizeof(wakeupmon_args));
+               break;
+       case RLIMIT_CPU_USAGE_MONITOR:
+               cpumon_flags = (uint32_t)uap->arg; // XXX temporarily stashing flags in argp (12592127)
+               error = mach_to_bsd_rv(task_cpu_usage_monitor_ctl(targetp->task, &cpumon_flags));
+               break;
+       case RLIMIT_THREAD_CPULIMITS:
+               cpulimits_flags = (uint32_t)uap->arg; // only need a limited set of bits, pass in void * argument
+
+               if (uap->pid != -1) {
+                       error = EINVAL;
+                       break;
+               }
+
+               uint8_t percent = 0;
+               uint32_t ms_refill = 0;
+               uint64_t ns_refill;
+
+               percent = (uint8_t)(cpulimits_flags & 0xffU);                                   /* low 8 bits for percent */
+               ms_refill = (cpulimits_flags >> 8) & 0xffffff;          /* next 24 bits represent ms refill value */
+               if (percent >= 100) {
+                       error = EINVAL;
+                       break;
+               }
+
+               ns_refill = ((uint64_t)ms_refill) * NSEC_PER_MSEC;
+
+               error = mach_to_bsd_rv(thread_set_cpulimit(THREAD_CPULIMIT_BLOCK, percent, ns_refill));
+               break;
+
+#if CONFIG_LEDGER_INTERVAL_MAX
+       case RLIMIT_FOOTPRINT_INTERVAL:
+               footprint_interval_flags = (uint32_t)uap->arg; // XXX temporarily stashing flags in argp (12592127)
+               /*
+                * There is currently only one option for this flavor.
+                */
+               if ((footprint_interval_flags & FOOTPRINT_INTERVAL_RESET) == 0) {
+                       error = EINVAL;
+                       break;
+               }
+               interval_max_footprint = get_task_phys_footprint_interval_max(targetp->task, TRUE);
+               break;
+#endif /* CONFIG_LEDGER_INTERVAL_MAX */
+       default:
+               error = EINVAL;
+               break;
+       }
+
+       proc_rele(targetp);
+       kauth_cred_unref(&target_cred);
+
+       /*
+        * Return value from this function becomes errno to userland caller.
+        */
+       return error;
 }
 
+/*
+ * Return the current amount of CPU consumed by this thread (in either user or kernel mode)
+ */
+int
+thread_selfusage(struct proc *p __unused, struct thread_selfusage_args *uap __unused, uint64_t *retval)
+{
+       uint64_t runtime;
+
+       runtime = thread_get_runtime_self();
+       *retval = runtime;
+
+       return 0;
+}
+
+#if !MONOTONIC
+int
+thread_selfcounts(__unused struct proc *p, __unused struct thread_selfcounts_args *uap, __unused int *ret_out)
+{
+       return ENOTSUP;
+}
+#endif /* !MONOTONIC */