]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/kern_resource.c
xnu-4903.221.2.tar.gz
[apple/xnu.git] / bsd / kern / kern_resource.c
index 21da076bacaacfe12ed45b6277ca0031477ac921..cf55f42d5b4d62d6a9a13a5c9bebf57095f9010c 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  *
  *     @(#)kern_resource.c     8.5 (Berkeley) 1/21/94
  */
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections.  This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/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 <bsm/audit_kernel.h>
+#include <security/audit/audit.h>
 
 #include <machine/vmparam.h>
 
 #include <mach/mach_types.h>
 #include <mach/time_value.h>
+#include <mach/task.h>
 #include <mach/task_info.h>
 #include <mach/vm_map.h>
+#include <mach/mach_vm.h>
+#include <mach/thread_act.h>  /* for thread_policy_set( ) */
+#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 */
+#if NECP
+#include <net/necp.h>
+#endif /* NECP */
 
 #include <vm/vm_map.h>
 
+#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);
+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);
+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;      /* XXX */ 
+rlim_t maxsmap = MAXSSIZ - PAGE_MAX_SIZE;      /* XXX */ 
 
 /*
  * Limits on the number of open files per process, and the number
@@ -103,61 +147,147 @@ rlim_t maxsmap = MAXSSIZ;        /* XXX */
  *
  * Note: would be in kern/subr_param.c in FreeBSD.
  */
-int maxprocperuid = CHILD_MAX;         /* max # of procs per user */
-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,
+SYSCTL_INT(_kern, KERN_MAXPROCPERUID, maxprocperuid, CTLFLAG_RW | CTLFLAG_LOCKED,
                &maxprocperuid, 0, "Maximum processes allowed per userid" );
 
-SYSCTL_INT( _kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,       
+SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW | CTLFLAG_LOCKED,
                &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;
+};
+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;
+};
+static int ppgrp_donice_callback(proc_t p, void * arg);
 
 /*
  * Resource controls and accounting.
  */
 int
-getpriority(struct proc *curp, struct getpriority_args *uap, register_t *retval)
+getpriority(struct proc *curp, struct getpriority_args *uap, int32_t *retval)
 {
-       register struct proc *p;
-       register int low = PRIO_MAX + 1;
+       struct proc *p;
+       int low = PRIO_MAX + 1;
+       kauth_cred_t my_cred;
+       int refheld = 0;
+       int error = 0;
 
-       if (uap->who < 0)
+       /* would also test (uap->who < 0), but id_t is unsigned */
+       if (uap->who > 0x7fffffff)
                return (EINVAL);
 
        switch (uap->which) {
 
        case PRIO_PROCESS:
-               if (uap->who == 0)
+               if (uap->who == 0) {
                        p = curp;
-               else
-                       p = pfind(uap->who);
-               if (p == 0)
-                       break;
-               low = p->p_nice;
+                       low = p->p_nice;
+               } else {
+                       p = proc_find(uap->who);
+                       if (p == 0)
+                               break;
+                       low = p->p_nice;
+                       proc_rele(p);
+
+               }
                break;
 
        case PRIO_PGRP: {
-               register struct pgrp *pg;
+               struct pgrp *pg = PGRP_NULL;
 
-               if (uap->who == 0)
-                       pg = curp->p_pgrp;
-               else if ((pg = pgfind(uap->who)) == NULL)
+               if (uap->who == 0) {
+                       /* returns the pgrp to ref */
+                       pg = proc_pgrp(curp);
+                } else if ((pg = pgfind(uap->who)) == PGRP_NULL) {
                        break;
-               for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) {
+               }
+               /* No need for iteration as it is a simple scan */
+               pgrp_lock(pg);
+               PGMEMBERS_FOREACH(pg, p) {
                        if (p->p_nice < low)
                                low = p->p_nice;
                }
+               pgrp_unlock(pg);
+               pg_rele(pg);
                break;
        }
 
        case PRIO_USER:
                if (uap->who == 0)
                        uap->who = kauth_cred_getuid(kauth_cred_get());
-               for (p = allproc.lh_first; p != 0; p = p->p_list.le_next)
-                       if (kauth_cred_getuid(p->p_ucred) == uap->who &&
+
+               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)
                                low = p->p_nice;
+                       kauth_cred_unref(&my_cred);
+               }
+
+               proc_list_unlock();
+
+               break;
+
+       case PRIO_DARWIN_THREAD:
+               /* we currently only support the current thread */
+               if (uap->who != 0)
+                       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;
+               }
+
+               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:
@@ -169,18 +299,69 @@ getpriority(struct proc *curp, struct getpriority_args *uap, register_t *retval)
        return (0);
 }
 
+/* call back function used for proc iteration in PRIO_USER */
+static int
+puser_donice_callback(proc_t p, void * arg)
+{
+       int error, n;
+       struct puser_nice_args * pun = (struct puser_nice_args *)arg;
+       kauth_cred_t my_cred;
+
+       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)
+                       *pun->errorp = error;
+               if (pun->foundp != NULL) {
+                       n = *pun->foundp;
+                       *pun->foundp = n+1;
+               }
+       }
+       kauth_cred_unref(&my_cred);
+
+       return(PROC_RETURNED);
+}
+
+/* call back function used for proc iteration in PRIO_PGRP */
+static int
+ppgrp_donice_callback(proc_t p, void * arg)
+{
+       int error;
+       struct ppgrp_nice_args * pun = (struct ppgrp_nice_args *)arg;
+       int n;
+
+       error = donice(pun->curp, p, pun->prio);
+       if (pun->errorp != NULL)
+               *pun->errorp = error;
+       if (pun->foundp!= NULL) {
+               n = *pun->foundp;
+               *pun->foundp = n+1;
+       }
+
+       return(PROC_RETURNED);
+}
+
+/*
+ * Returns:    0                       Success
+ *             EINVAL
+ *             ESRCH
+ *     donice:EPERM
+ *     donice:EACCES
+ */
 /* ARGSUSED */
 int
-setpriority(struct proc *curp, struct setpriority_args *uap, __unused register_t *retval)
+setpriority(struct proc *curp, struct setpriority_args *uap, int32_t *retval)
 {
-       register struct proc *p;
+       struct proc *p;
        int found = 0, error = 0;
+       int refheld = 0;
 
        AUDIT_ARG(cmd, uap->which);
        AUDIT_ARG(owner, uap->who, 0);
-       AUDIT_ARG(value, uap->prio);
+       AUDIT_ARG(value32, uap->prio);
 
-       if (uap->who < 0)
+       /* would also test (uap->who < 0), but id_t is unsigned */
+       if (uap->who > 0x7fffffff)
                return (EINVAL);
 
        switch (uap->which) {
@@ -188,73 +369,510 @@ setpriority(struct proc *curp, struct setpriority_args *uap, __unused register_t
        case PRIO_PROCESS:
                if (uap->who == 0)
                        p = curp;
-               else
-                       p = pfind(uap->who);
-               if (p == 0)
-                       break;
+               else {
+                       p = proc_find(uap->who);
+                       if (p == 0)
+                               break;
+                       refheld = 1;
+               }
                error = donice(curp, p, uap->prio);
                found++;
+               if (refheld != 0)
+                       proc_rele(p);
                break;
 
        case PRIO_PGRP: {
-               register struct pgrp *pg;
+               struct pgrp *pg = PGRP_NULL;
+               struct ppgrp_nice_args ppgrp;
                 
-               if (uap->who == 0)
-                       pg = curp->p_pgrp;
-               else if ((pg = pgfind(uap->who)) == NULL)
+               if (uap->who == 0) {
+                       pg = proc_pgrp(curp);
+                } else if ((pg = pgfind(uap->who)) == PGRP_NULL)
                        break;
-               for (p = pg->pg_members.lh_first; p != 0;
-                   p = p->p_pglist.le_next) {
-                       error = donice(curp, p, uap->prio);
-                       found++;
-               }
+
+               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);
+
                break;
        }
 
-       case PRIO_USER:
+       case PRIO_USER: {
+               struct puser_nice_args punice;
+
                if (uap->who == 0)
                        uap->who = kauth_cred_getuid(kauth_cred_get());
-               for (p = allproc.lh_first; p != 0; p = p->p_list.le_next)
-                       if (kauth_cred_getuid(p->p_ucred) == uap->who) {
-                               error = donice(curp, p, uap->prio);
-                               found++;
-                       }
+
+               punice.curp = curp;
+               punice.prio = uap->prio;
+               punice.who = uap->who;
+               punice.foundp = &found;
+               error = 0;
+               punice.errorp = &error;
+               proc_iterate(PROC_ALLPROCLIST, puser_donice_callback, (void *)&punice, NULL, NULL);
+
+               break;
+       }
+
+       case PRIO_DARWIN_THREAD: {
+               /* we currently only support the current thread */
+               if (uap->who != 0)
+                       return (EINVAL);
+
+               error = do_background_thread(current_thread(), uap->prio);
+               found++;
+               break;
+       }
+
+       case PRIO_DARWIN_PROCESS: {
+               if (uap->who == 0)
+                       p = curp;
+               else {
+                       p = proc_find(uap->who);
+                       if (p == 0)
+                               break;
+                       refheld = 1;
+               }
+
+               error = do_background_proc(curp, p, 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)
+                       proc_rele(p);
                break;
+       }
 
        default:
                return (EINVAL);
        }
        if (found == 0)
                return (ESRCH);
+       if (error == EIDRM) {
+               *retval = -2;
+               error = 0;
+       }
        return (error);
 }
 
+
+/*
+ * Returns:    0                       Success
+ *             EPERM
+ *             EACCES
+ *     mac_check_proc_sched:???
+ */
 int
-donice(curp, chgp, n)
-       register struct proc *curp, *chgp;
-       register int n;
+donice(struct proc *curp, struct proc *chgp, int n)
 {
-       kauth_cred_t ucred = curp->p_ucred;
+       int error = 0;
+       kauth_cred_t ucred;
+       kauth_cred_t my_cred;
 
-       if (suser(ucred, NULL) && ucred->cr_ruid &&
-           kauth_cred_getuid(ucred) != kauth_cred_getuid(chgp->p_ucred) &&
-           ucred->cr_ruid != kauth_cred_getuid(chgp->p_ucred))
-               return (EPERM);
+       ucred = kauth_cred_proc_ref(curp);
+       my_cred = kauth_cred_proc_ref(chgp);
+
+       if (suser(ucred, NULL) && kauth_cred_getruid(ucred) &&
+           kauth_cred_getuid(ucred) != kauth_cred_getuid(my_cred) &&
+           kauth_cred_getruid(ucred) != kauth_cred_getuid(my_cred)) {
+               error = EPERM;
+               goto out;
+       }
        if (n > PRIO_MAX)
                n = PRIO_MAX;
        if (n < PRIO_MIN)
                n = PRIO_MIN;
-       if (n < chgp->p_nice && suser(ucred, &curp->p_acflag))
-               return (EACCES);
+       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) 
+               goto out;
+#endif
+       proc_lock(chgp);
        chgp->p_nice = n;
+       proc_unlock(chgp);
        (void)resetpriority(chgp);
-       return (0);
+out:
+       kauth_cred_unref(&ucred);
+       kauth_cred_unref(&my_cred);
+       return (error);
+}
+
+static int
+set_gpudeny_proc(struct proc *curp, struct proc *targetp, int priority)
+{
+       int error = 0;
+       kauth_cred_t ucred;
+       kauth_cred_t target_cred;
+
+       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)) {
+               error = EPERM;
+               goto out;
+       }
+
+       if (curp == targetp) {
+               error = EPERM;
+               goto out;
+       }
+
+#if CONFIG_MACF
+       error = mac_proc_check_sched(curp, targetp);
+       if (error)
+               goto out;
+#endif
+
+       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;
+       }
+
+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;
+               }
+       }
+
+       if (curp != targetp) {
+#if CONFIG_MACF
+               if ((error = mac_proc_check_sched(curp, targetp)))
+                       goto out;
+#endif
+       }
+
+       proc_get_darwinbgstate(proc_task(targetp), &flagsp);
+       if ((flagsp & PROC_FLAG_APPLICATION) != PROC_FLAG_APPLICATION) {
+               error = ENOTSUP;
+               goto out;
+       }
+
+       integer_t role = 0;
+
+       if ((error = proc_darwin_role_to_task_role(priority, &role)))
+               goto out;
+
+       proc_set_task_policy(proc_task(targetp), TASK_POLICY_ATTRIBUTE,
+                            TASK_POLICY_ROLE, role);
+
+out:
+       kauth_cred_unref(&target_cred);
+       return (error);
+}
+
+static int
+proc_get_darwin_role(proc_t curp, proc_t targetp, int *priority)
+{
+       int error = 0;
+       int role = 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)) {
+               error = EPERM;
+               goto out;
+       }
+
+       if (curp != targetp) {
+#if CONFIG_MACF
+               if ((error = mac_proc_check_sched(curp, targetp)))
+                       goto out;
+#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);
+}
+
+
+static int
+get_background_proc(struct proc *curp, struct proc *targetp, int *priority)
+{
+       int external = 0;
+       int error = 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)) {
+               error = EPERM;
+               goto out;
+       }
+
+       external = (curp == targetp) ? TASK_POLICY_INTERNAL : TASK_POLICY_EXTERNAL;
+
+       *priority = proc_get_task_policy(current_task(), external, TASK_POLICY_DARWIN_BG);
+
+out:
+       kauth_cred_unref(&target_cred);
+       return (error);
+}
+
+static int
+do_background_proc(struct proc *curp, struct proc *targetp, int priority)
+{
+#if !CONFIG_MACF
+#pragma unused(curp)
+#endif
+       int error = 0;
+       kauth_cred_t ucred;
+       kauth_cred_t target_cred;
+       int external;
+       int enable;
+
+       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;
+       }
+
+#if CONFIG_MACF
+       error = mac_proc_check_sched(curp, targetp);
+       if (error) 
+               goto out;
+#endif
+
+       external = (curp == targetp) ? TASK_POLICY_INTERNAL : TASK_POLICY_EXTERNAL;
+
+       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;
+       }
+
+       proc_set_task_policy(proc_task(targetp), external, TASK_POLICY_DARWIN_BG, enable);
+
+out:
+       kauth_cred_unref(&target_cred);
+       return (error);
+}
+
+static void 
+do_background_socket(struct proc *p, thread_t thread)
+{
+#if SOCKETS
+       struct filedesc                     *fdp;
+       struct fileproc                     *fp;
+       int                                 i, background;
+
+       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) {
+                       fdp = p->p_fd;
+
+                       for (i = 0; i < fdp->fd_nfiles; i++) {
+                               fp = fdp->fd_ofiles[i];
+                               if (fp == NULL || (fdp->fd_ofileflags[i] & UF_RESERVED) != 0) {
+                                       continue;
+                               }
+                               if (FILEGLOB_DTYPE(fp->f_fglob) == DTYPE_SOCKET) {
+                                       struct socket *sockp = (struct socket *)fp->f_fglob->fg_data;
+                                       socket_set_traffic_mgt_flags(sockp, TRAFFIC_MGT_SO_BACKGROUND);
+                                       sockp->so_background_thread = NULL;
+                               }
+#if NECP
+                               else if (FILEGLOB_DTYPE(fp->f_fglob) == DTYPE_NETPOLICY) {
+                                       necp_set_client_as_background(p, fp, background);
+                               }
+#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.  
+                */
+               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) {
+                               continue;
+                       }
+                       if (FILEGLOB_DTYPE(fp->f_fglob) == DTYPE_SOCKET) {
+                               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 NECP
+                       else if (FILEGLOB_DTYPE(fp->f_fglob) == DTYPE_NETPOLICY) {
+                               necp_set_client_as_background(p, fp, background);
+                       }
+#endif /* NECP */
+               }
+       }
+
+       proc_fdunlock(p);
+#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:
+ */
 /* ARGSUSED */
 int
-setrlimit(struct proc *p, register struct setrlimit_args *uap, __unused register_t *retval)
+setrlimit(struct proc *p, struct setrlimit_args *uap, __unused int32_t *retval)
 {
        struct rlimit alim;
        int error;
@@ -262,36 +880,92 @@ setrlimit(struct proc *p, register struct setrlimit_args *uap, __unused register
        if ((error = copyin(uap->rlp, (caddr_t)&alim,
            sizeof (struct rlimit))))
                return (error);
+
        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
+ *             case that the current usage (e.g. RLIMIT_STACK) is already
+ *             in excess of the requested limit.
+ */
 int
-dosetrlimit(p, which, limp)
-       struct proc *p;
-       u_int which;
-       struct rlimit *limp;
+dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
 {
-       register struct rlimit *alimp;
+       struct rlimit *alimp;
        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)
+               return EINVAL;
+
        if (limp->rlim_cur > alimp->rlim_max || 
            limp->rlim_max > alimp->rlim_max)
-               if ((error = suser(kauth_cred_get(), &p->p_acflag)))
+               if ((error = suser(kauth_cred_get(), &p->p_acflag))) {
                        return (error);
-       if (limp->rlim_cur > limp->rlim_max)
-               limp->rlim_cur = limp->rlim_max;
-       if (p->p_limit->p_refcnt > 1 &&
-           (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
-               p->p_limit->p_refcnt--;
-               p->p_limit = limcopy(p->p_limit);
-               alimp = &p->p_rlimit[which];
        }
 
+       proc_limitblock(p);
+
+       if ((error = proc_limitreplace(p)) != 0) {
+               proc_limitunblock(p);
+               return(error);
+       }
+
+       alimp = &p->p_rlimit[which];
+       
        switch (which) {
 
+       case RLIMIT_CPU:
+               if (limp->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;
+
+                       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);
+                       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_usec = 0;
+                       timersub(&tv, &ttv, &p->p_rlim_cpu);
+
+                       timerclear(&tv);
+                       if (timercmp(&p->p_rlim_cpu, &tv, >))
+                               task_vtimer_set(p->task, TASK_VTIMER_RLIM);
+                       else {
+                               task_vtimer_clear(p->task, TASK_VTIMER_RLIM);
+
+                               timerclear(&p->p_rlim_cpu);
+
+                               psignal(p, SIGXCPU);
+                       }
+               }
+               break;
+
        case RLIMIT_DATA:
                if (limp->rlim_cur > maxdmap)
                        limp->rlim_cur = maxdmap;
@@ -300,55 +974,130 @@ dosetrlimit(p, which, limp)
                break;
 
        case RLIMIT_STACK:
-               if (limp->rlim_cur > maxsmap)
-                       limp->rlim_cur = maxsmap;
-               if (limp->rlim_max > maxsmap)
-                       limp->rlim_max = maxsmap;
+               /* Disallow illegal stack size instead of clipping */
+               if (limp->rlim_cur > maxsmap ||
+                   limp->rlim_max > maxsmap) {
+                       if (posix) {
+                               error = EINVAL;
+                               goto out;
+                       }
+                       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;
+                       }
+               }
+
                /*
                 * Stack is allocated to the max at exec time with only
                 * "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) {
+               if (limp->rlim_cur > alimp->rlim_cur) {
                        user_addr_t addr;
                        user_size_t size;
                        
-                       if (limp->rlim_cur > alimp->rlim_cur) {
                                /* 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 + alimp->rlim_cur;
-#else STACK_GROWTH_UP
-                               addr = p->user_stack - alimp->rlim_cur;
-                               addr -= size;
-#endif /* STACK_GROWTH_UP */
-                               if (mach_vm_allocate(current_map(), 
-                                                    &addr, size,
-                                                    VM_FLAGS_FIXED) != KERN_SUCCESS)
-                                       return(EINVAL);
-                       } else {
-                               /* shrink stack */
+                       addr = p->user_stack - round_page_64(limp->rlim_cur);
+                       kr = mach_vm_protect(current_map(), 
+                                            addr, size,
+                                            FALSE, VM_PROT_DEFAULT);
+                       if (kr != KERN_SUCCESS) {
+                               error =  EINVAL;
+                               goto out;
                        }
-               }
-               break;
+               } else if (limp->rlim_cur < alimp->rlim_cur) {
+                       user_addr_t addr;
+                       user_size_t size;
+                       user_addr_t cur_sp;
+
+                               /* 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 (cur_sp <= p->user_stack &&
+                           cur_sp > (p->user_stack -
+                                     round_page_64(alimp->rlim_cur))) {
+                               /* 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;
+                       }
+                               
+                       size = round_page_64(alimp->rlim_cur);
+                       size -= round_page_64(limp->rlim_cur);
+
+                       addr = p->user_stack - round_page_64(alimp->rlim_cur);
+
+                       kr = mach_vm_protect(current_map(),
+                                            addr, size,
+                                            FALSE, VM_PROT_NONE);
+                       if (kr != KERN_SUCCESS) {
+                               error =  EINVAL;
+                               goto out;
+                       }
+               } else {
+                       /* no change ... */
+               }
+               break;
 
        case RLIMIT_NOFILE:
                /* 
-               * Only root can set the maxfiles limits, as it is systemwide resource
+                * 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 > maxfiles)
+               if ( kauth_cred_issuser(kauth_cred_get()) ) {
+                       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 > maxfiles)
+                       }
+                       if (limp->rlim_max != alimp->rlim_max &&
+                           limp->rlim_max > (rlim_t)maxfiles)
                                limp->rlim_max = maxfiles;
                }
                else {
-                       if (limp->rlim_cur > maxfilesperproc)
+                       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 > maxfilesperproc)
+                       }
+                       if (limp->rlim_max != alimp->rlim_max &&
+                           limp->rlim_max > (rlim_t)maxfilesperproc)
                                limp->rlim_max = maxfilesperproc;
                }
                break;
@@ -359,32 +1108,54 @@ dosetrlimit(p, which, limp)
                 * systemwide resource; all others are limited to
                 * maxprocperuid (presumably less than maxproc).
                 */
-               if ( is_suser() ) {
-                       if (limp->rlim_cur > maxproc)
+               if ( kauth_cred_issuser(kauth_cred_get()) ) {
+                       if (limp->rlim_cur > (rlim_t)maxproc)
                                limp->rlim_cur = maxproc;
-                       if (limp->rlim_max > maxproc)
+                       if (limp->rlim_max > (rlim_t)maxproc)
                                limp->rlim_max = maxproc;
                } 
                else {
-                       if (limp->rlim_cur > maxprocperuid)
+                       if (limp->rlim_cur > (rlim_t)maxprocperuid)
                                limp->rlim_cur = maxprocperuid;
-                       if (limp->rlim_max > maxprocperuid)
+                       if (limp->rlim_max > (rlim_t)maxprocperuid)
                                limp->rlim_max = maxprocperuid;
                }
                break;
+
+       case RLIMIT_MEMLOCK:
+               /*
+                * Tell the Mach VM layer about the new limit value.
+                */
+
+               vm_map_set_user_wire_limit(current_map(), limp->rlim_cur);
+               break;
                
        } /* switch... */
+       proc_lock(p);
        *alimp = *limp;
-       return (0);
+       proc_unlock(p);
+       error = 0;
+out:
+       proc_limitunblock(p);
+       return (error);
 }
 
 /* ARGSUSED */
 int
-getrlimit(struct proc *p, register struct getrlimit_args *uap, __unused register_t *retval)
+getrlimit(struct proc *p, struct getrlimit_args *uap, __unused int32_t *retval)
 {
+       struct rlimit lim = {};
+
+       /*
+        * Take out flag now in case we need to use it to trigger variant
+        * behaviour later.
+        */
+       uap->which &= ~_RLIMIT_POSIX_FLAG;
+
        if (uap->which >= RLIM_NLIMITS)
                return (EINVAL);
-       return (copyout((caddr_t)&p->p_rlimit[uap->which],
+       proc_limitget(p, uap->which, &lim);
+       return (copyout((caddr_t)&lim,
                        uap->rlp, sizeof (struct rlimit)));
 }
 
@@ -392,12 +1163,9 @@ getrlimit(struct proc *p, register struct getrlimit_args *uap, __unused register
  * Transform the running time and tick information in proc p into user,
  * system, and interrupt time usage.
  */
+/* No lock on proc is held for this.. */
 void
-calcru(p, up, sp, ip)
-       register struct proc *p;
-       register struct timeval *up;
-       register struct timeval *sp;
-       register struct timeval *ip;
+calcru(struct proc *p, struct timeval *up, struct timeval *sp, struct timeval *ip)
 {
        task_t                  task;
 
@@ -408,14 +1176,16 @@ calcru(p, up, sp, ip)
 
        task = p->task;
        if (task) {
-               task_basic_info_data_t tinfo;
+               mach_task_basic_info_data_t tinfo;
                task_thread_times_info_data_t ttimesinfo;
-               int task_info_stuff, task_ttimes_stuff;
+               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;
 
-               task_info_stuff = TASK_BASIC_INFO_COUNT;
-               task_info(task, TASK_BASIC_INFO,
-                         &tinfo, &task_info_stuff);
+               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;
@@ -423,9 +1193,9 @@ calcru(p, up, sp, ip)
                timeradd(&ut, up, up);
                timeradd(&st, sp, sp);
 
-               task_ttimes_stuff = TASK_THREAD_TIMES_INFO_COUNT;
+               task_ttimes_count = TASK_THREAD_TIMES_INFO_COUNT;
                task_info(task, TASK_THREAD_TIMES_INFO,
-                         &ttimesinfo, &task_ttimes_stuff);
+                         (task_info_t)&ttimesinfo, &task_ttimes_count);
 
                ut.tv_sec = ttimesinfo.user_time.seconds;
                ut.tv_usec = ttimesinfo.user_time.microseconds;
@@ -433,31 +1203,61 @@ calcru(p, up, sp, ip)
                st.tv_usec = ttimesinfo.system_time.microseconds;
                timeradd(&ut, up, up);
                timeradd(&st, sp, sp);
+
+               task_events_count = TASK_EVENTS_INFO_COUNT;
+               task_info(task, TASK_EVENTS_INFO,
+                         (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);
+               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_nivcsw = 0;
+
+               p->p_stats->p_ru.ru_maxrss = tinfo.resident_size_max;
        }
 }
 
-__private_extern__ void munge_rusage(struct rusage *a_rusage_p, struct user_rusage *a_user_rusage_p);
+__private_extern__ void munge_user64_rusage(struct rusage *a_rusage_p, struct user64_rusage *a_user_rusage_p);
+__private_extern__ void munge_user32_rusage(struct rusage *a_rusage_p, struct user32_rusage *a_user_rusage_p);
 
 /* ARGSUSED */
 int
-getrusage(register struct proc *p, register struct getrusage_args *uap, __unused register_t *retval)
+getrusage(struct proc *p, struct getrusage_args *uap, __unused int32_t *retval)
 {
        struct rusage *rup, rubuf;
-       struct user_rusage rubuf64;
+       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;
+
 
        switch (uap->who) {
        case RUSAGE_SELF:
+               calcru(p, &utime, &stime, NULL);
+               proc_lock(p);
                rup = &p->p_stats->p_ru;
-               calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
-               // LP64todo: proc struct should have 64 bit version of struct
+               rup->ru_utime = utime;
+               rup->ru_stime = stime;
+
                rubuf = *rup;
+               proc_unlock(p);
+
                break;
 
        case RUSAGE_CHILDREN:
+               proc_lock(p);
                rup = &p->p_stats->p_cru;
                rubuf = *rup;
+               proc_unlock(p);
                break;
 
        default:
@@ -466,17 +1266,21 @@ getrusage(register struct proc *p, register struct getrusage_args *uap, __unused
        if (IS_64BIT_PROCESS(p)) {
                retsize = sizeof(rubuf64);
                retbuf = (caddr_t)&rubuf64;
-               munge_rusage(&rubuf, &rubuf64);
+               munge_user64_rusage(&rubuf, &rubuf64);
+       } else {
+               retsize = sizeof(rubuf32);
+               retbuf = (caddr_t)&rubuf32;
+               munge_user32_rusage(&rubuf, &rubuf32);
        }
+
        return (copyout(retbuf, uap->rusage, retsize));
 }
 
 void
-ruadd(ru, ru2)
-       register struct rusage *ru, *ru2;
+ruadd(struct rusage *ru, struct rusage *ru2)
 {
-       register long *ip, *ip2;
-       register int i;
+       long *ip, *ip2;
+       long i;
 
        timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
        timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
@@ -488,23 +1292,744 @@ ruadd(ru, ru2)
 }
 
 /*
- * Make a copy of the plimit structure.
- * We share these structures copy-on-write after fork,
- * and copy when a limit is changed.
+ * 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.
  */
-struct plimit *
-limcopy(lim)
-       struct plimit *lim;
+void
+update_rusage_info_child(struct rusage_info_child *ri, rusage_info_current *ri_current)
+{
+       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_limitget(proc_t p, int which, struct rlimit * limp)
+{
+       proc_list_lock();
+       limp->rlim_cur = p->p_rlimit[which].rlim_cur;
+       limp->rlim_max = p->p_rlimit[which].rlim_max;
+       proc_list_unlock();
+}
+
+
+void
+proc_limitdrop(proc_t p, int exiting)
+{
+       struct  plimit * freelim = NULL;
+       struct  plimit * freeoldlim = NULL;
+
+       proc_list_lock();
+
+       if (--p->p_limit->pl_refcnt == 0) { 
+               freelim = p->p_limit;
+               p->p_limit = NULL;
+       }
+       if ((exiting != 0) && (p->p_olimit != NULL) && (--p->p_olimit->pl_refcnt == 0)) {
+               freeoldlim =  p->p_olimit;
+               p->p_olimit = NULL;
+       }
+
+       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);
+}
+
+
+void
+proc_limitfork(proc_t parent, proc_t child)
 {
-       register struct plimit *copy;
+       proc_list_lock();
+       child->p_limit = parent->p_limit;
+       child->p_limit->pl_refcnt++;
+       child->p_olimit = NULL;
+       proc_list_unlock();
+}
+
+void
+proc_limitblock(proc_t p)
+{
+       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);
+       }
+       p->p_lflag |= P_LLIMCHANGE;
+       proc_unlock(p);
+
+}
+
+
+void
+proc_limitunblock(proc_t p)
+{
+       proc_lock(p);
+       p->p_lflag &= ~P_LLIMCHANGE;
+       if (p->p_lflag & P_LLIMWAIT) {
+               p->p_lflag &= ~P_LLIMWAIT;
+               wakeup(&p->p_olimit);
+       }
+       proc_unlock(p);
+}
+
+/* This is called behind serialization provided by proc_limitblock/unlbock */
+int
+proc_limitreplace(proc_t p)
+{
+       struct plimit *copy;
+
+
+       proc_list_lock();
+
+       if (p->p_limit->pl_refcnt == 1) {
+               proc_list_unlock();
+               return(0);
+       }
+               
+       proc_list_unlock();
 
        MALLOC_ZONE(copy, struct plimit *,
-                       sizeof(struct plimit), M_SUBPROC, M_WAITOK);
-       if (copy == NULL)
-               panic("limcopy");
-       bcopy(lim->pl_rlimit, copy->pl_rlimit,
+                       sizeof(struct plimit), M_PLIMIT, M_WAITOK);
+       if (copy == NULL) {
+               return(ENOMEM);
+       }
+
+       proc_list_lock();
+       bcopy(p->p_limit->pl_rlimit, copy->pl_rlimit,
            sizeof(struct rlimit) * RLIM_NLIMITS);
-       copy->p_lflags = 0;
-       copy->p_refcnt = 1;
-       return (copy);
+       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();
+
+       return(0);
+}
+
+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);
+
+/*
+ * iopolicysys
+ *
+ * Description:        System call MUX for use in manipulating I/O policy attributes of the current process or thread
+ *
+ * Parameters: cmd                             Policy command
+ *             arg                             Pointer to policy arguments
+ *
+ * Returns:    0                               Success
+ *             EINVAL                          Invalid command or invalid policy arguments
+ *
+ */
+int
+iopolicysys(struct proc *p, struct iopolicysys_args *uap, int32_t *retval)
+{
+       int     error = 0;
+       struct _iopol_param_t iop_param;
+
+       if ((error = copyin(uap->arg, &iop_param, sizeof(iop_param))) != 0)
+               goto out;
+
+       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;
+               default:
+                       error = EINVAL;
+                       goto out;
+       }
+
+       /* 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:
+                       thread = THREAD_NULL;
+                       policy_flavor = TASK_POLICY_IOPOL;
+                       break;
+
+               case IOPOL_SCOPE_THREAD:
+                       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;
+                                               }
+                                               /* otherwise, fall through to the error case. */
+                                       default:
+                                               error = EINVAL;
+                                               goto out;
+                               }
+                       }
+                       break;
+
+               case IOPOL_SCOPE_DARWIN_BG:
+#if CONFIG_EMBEDDED
+                       /* Embedded doesn't want this as BG is always IOPOL_THROTTLE */
+                       error = ENOTSUP;
+                       goto out;
+#else /* CONFIG_EMBEDDED */
+                       thread = THREAD_NULL;
+                       policy_flavor = TASK_POLICY_DARWIN_BG_IOPOL;
+                       break;
+#endif /* CONFIG_EMBEDDED */
+
+               default:
+                       error = EINVAL;
+                       goto out;
+       }
+
+       /* Validate policy */
+       if (cmd == IOPOL_CMD_SET) {
+               switch (policy) {
+                       case IOPOL_DEFAULT:
+                               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 (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 (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 */
+                       break;
+       }
+
+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:
+                       /* 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();
+                       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_ATIME_UPDATES_DEFAULT:
+                       case IOPOL_ATIME_UPDATES_OFF:
+                               break;
+                       default:
+                               error = EINVAL;
+                               goto out;
+               }
+       }
+
+       /* Perform command */
+       switch(cmd) {
+               case IOPOL_CMD_SET:
+                       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);
+}
+
+/* BSD call back function for task_policy networking changes */
+void
+proc_apply_task_networkbg(void * bsd_info, thread_t thread)
+{
+       assert(bsd_info != PROC_NULL);
+
+       pid_t pid = proc_pid((proc_t)bsd_info);
+
+       proc_t p = proc_find(pid);
+
+       if (p != PROC_NULL) {
+               assert(p == (proc_t)bsd_info);
+
+               do_background_socket(p, thread);
+               proc_rele(p);
+       }
+}
+
+void
+gather_rusage_info(proc_t p, rusage_info_current *ru, int flavor)
+{
+       struct rusage_info_child *ri_child;
+
+       assert(p->p_stats != NULL);
+       memset(ru, 0, sizeof(*ru));
+       switch(flavor) {
+       case RUSAGE_INFO_V4:
+               ru->ri_logical_writes = get_task_logical_writes(p->task);
+               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);
+       /* fall through */
+
+       case RUSAGE_INFO_V3:
+               fill_task_qos_rusage(p->task, ru);
+               fill_task_billed_usage(p->task, ru);
+               /* fall through */
+
+       case RUSAGE_INFO_V2:
+               fill_task_io_rusage(p->task, ru);
+               /* fall through */
+
+       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);
+               /* fall through */
+
+       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;
+
+       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);
+}
+
+static int
+mach_to_bsd_rv(int mach_rv)
+{
+       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;
+}
+
+/*
+ * 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)
+{
+       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 = 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 = 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 */