From: Chris Johns <chr...@rtems.org>

Update #4475
---
 freebsd/sys/kern/kern_prot.c     | 2247 ++++++++++++++++++++++++++++++
 freebsd/sys/kern/kern_resource.c | 1539 ++++++++++++++++++++
 2 files changed, 3786 insertions(+)
 create mode 100644 freebsd/sys/kern/kern_prot.c
 create mode 100644 freebsd/sys/kern/kern_resource.c

diff --git a/freebsd/sys/kern/kern_prot.c b/freebsd/sys/kern/kern_prot.c
new file mode 100644
index 00000000..a62b6f76
--- /dev/null
+++ b/freebsd/sys/kern/kern_prot.c
@@ -0,0 +1,2247 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
+ *     The Regents of the University of California.
+ * (c) UNIX System Laboratories, Inc.
+ * Copyright (c) 2000-2001 Robert N. M. Watson.
+ * All rights reserved.
+ *
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *     @(#)kern_prot.c 8.6 (Berkeley) 1/21/94
+ */
+
+/*
+ * System calls related to processes and protection
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_inet.h"
+#include "opt_inet6.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/acct.h>
+#include <sys/kdb.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/loginclass.h>
+#include <sys/malloc.h>
+#include <sys/mutex.h>
+#include <sys/refcount.h>
+#include <sys/sx.h>
+#include <sys/priv.h>
+#include <sys/proc.h>
+#include <sys/sysent.h>
+#include <sys/sysproto.h>
+#include <sys/jail.h>
+#include <sys/pioctl.h>
+#include <sys/racct.h>
+#include <sys/rctl.h>
+#include <sys/resourcevar.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/syscallsubr.h>
+#include <sys/sysctl.h>
+
+#ifdef REGRESSION
+FEATURE(regression,
+    "Kernel support for interfaces necessary for regression testing (SECURITY 
RISK!)");
+#endif
+
+#include <security/audit/audit.h>
+#include <security/mac/mac_framework.h>
+
+static MALLOC_DEFINE(M_CRED, "cred", "credentials");
+
+SYSCTL_NODE(_security, OID_AUTO, bsd, CTLFLAG_RW, 0, "BSD security policy");
+
+static void crsetgroups_locked(struct ucred *cr, int ngrp,
+    gid_t *groups);
+
+#ifndef _SYS_SYSPROTO_H_
+struct getpid_args {
+       int     dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getpid(struct thread *td, struct getpid_args *uap)
+{
+       struct proc *p = td->td_proc;
+
+       td->td_retval[0] = p->p_pid;
+#if defined(COMPAT_43)
+       if (SV_PROC_FLAG(p, SV_AOUT))
+               td->td_retval[1] = kern_getppid(td);
+#endif
+       return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getppid_args {
+        int     dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getppid(struct thread *td, struct getppid_args *uap)
+{
+
+       td->td_retval[0] = kern_getppid(td);
+       return (0);
+}
+
+int
+kern_getppid(struct thread *td)
+{
+       struct proc *p = td->td_proc;
+
+       return (p->p_oppid);
+}
+
+/*
+ * Get process group ID; note that POSIX getpgrp takes no parameter.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct getpgrp_args {
+        int     dummy;
+};
+#endif
+int
+sys_getpgrp(struct thread *td, struct getpgrp_args *uap)
+{
+       struct proc *p = td->td_proc;
+
+       PROC_LOCK(p);
+       td->td_retval[0] = p->p_pgrp->pg_id;
+       PROC_UNLOCK(p);
+       return (0);
+}
+
+/* Get an arbitrary pid's process group id */
+#ifndef _SYS_SYSPROTO_H_
+struct getpgid_args {
+       pid_t   pid;
+};
+#endif
+int
+sys_getpgid(struct thread *td, struct getpgid_args *uap)
+{
+       struct proc *p;
+       int error;
+
+       if (uap->pid == 0) {
+               p = td->td_proc;
+               PROC_LOCK(p);
+       } else {
+               p = pfind(uap->pid);
+               if (p == NULL)
+                       return (ESRCH);
+               error = p_cansee(td, p);
+               if (error) {
+                       PROC_UNLOCK(p);
+                       return (error);
+               }
+       }
+       td->td_retval[0] = p->p_pgrp->pg_id;
+       PROC_UNLOCK(p);
+       return (0);
+}
+
+/*
+ * Get an arbitrary pid's session id.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct getsid_args {
+       pid_t   pid;
+};
+#endif
+int
+sys_getsid(struct thread *td, struct getsid_args *uap)
+{
+       struct proc *p;
+       int error;
+
+       if (uap->pid == 0) {
+               p = td->td_proc;
+               PROC_LOCK(p);
+       } else {
+               p = pfind(uap->pid);
+               if (p == NULL)
+                       return (ESRCH);
+               error = p_cansee(td, p);
+               if (error) {
+                       PROC_UNLOCK(p);
+                       return (error);
+               }
+       }
+       td->td_retval[0] = p->p_session->s_sid;
+       PROC_UNLOCK(p);
+       return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getuid_args {
+        int     dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getuid(struct thread *td, struct getuid_args *uap)
+{
+
+       td->td_retval[0] = td->td_ucred->cr_ruid;
+#if defined(COMPAT_43)
+       td->td_retval[1] = td->td_ucred->cr_uid;
+#endif
+       return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct geteuid_args {
+        int     dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_geteuid(struct thread *td, struct geteuid_args *uap)
+{
+
+       td->td_retval[0] = td->td_ucred->cr_uid;
+       return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getgid_args {
+        int     dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getgid(struct thread *td, struct getgid_args *uap)
+{
+
+       td->td_retval[0] = td->td_ucred->cr_rgid;
+#if defined(COMPAT_43)
+       td->td_retval[1] = td->td_ucred->cr_groups[0];
+#endif
+       return (0);
+}
+
+/*
+ * Get effective group ID.  The "egid" is groups[0], and could be obtained
+ * via getgroups.  This syscall exists because it is somewhat painful to do
+ * correctly in a library function.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct getegid_args {
+        int     dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getegid(struct thread *td, struct getegid_args *uap)
+{
+
+       td->td_retval[0] = td->td_ucred->cr_groups[0];
+       return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getgroups_args {
+       u_int   gidsetsize;
+       gid_t   *gidset;
+};
+#endif
+int
+sys_getgroups(struct thread *td, struct getgroups_args *uap)
+{
+       struct ucred *cred;
+       u_int ngrp;
+       int error;
+
+       cred = td->td_ucred;
+       ngrp = cred->cr_ngroups;
+
+       if (uap->gidsetsize == 0) {
+               error = 0;
+               goto out;
+       }
+       if (uap->gidsetsize < ngrp)
+               return (EINVAL);
+
+       error = copyout(cred->cr_groups, uap->gidset, ngrp * sizeof(gid_t));
+out:
+       td->td_retval[0] = ngrp;
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setsid_args {
+        int     dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setsid(struct thread *td, struct setsid_args *uap)
+{
+       struct pgrp *pgrp;
+       int error;
+       struct proc *p = td->td_proc;
+       struct pgrp *newpgrp;
+       struct session *newsess;
+
+       error = 0;
+       pgrp = NULL;
+
+       newpgrp = malloc(sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO);
+       newsess = malloc(sizeof(struct session), M_SESSION, M_WAITOK | M_ZERO);
+
+       sx_xlock(&proctree_lock);
+
+       if (p->p_pgid == p->p_pid || (pgrp = pgfind(p->p_pid)) != NULL) {
+               if (pgrp != NULL)
+                       PGRP_UNLOCK(pgrp);
+               error = EPERM;
+       } else {
+               (void)enterpgrp(p, p->p_pid, newpgrp, newsess);
+               td->td_retval[0] = p->p_pid;
+               newpgrp = NULL;
+               newsess = NULL;
+       }
+
+       sx_xunlock(&proctree_lock);
+
+       if (newpgrp != NULL)
+               free(newpgrp, M_PGRP);
+       if (newsess != NULL)
+               free(newsess, M_SESSION);
+
+       return (error);
+}
+
+/*
+ * set process group (setpgid/old setpgrp)
+ *
+ * caller does setpgid(targpid, targpgid)
+ *
+ * pid must be caller or child of caller (ESRCH)
+ * if a child
+ *     pid must be in same session (EPERM)
+ *     pid can't have done an exec (EACCES)
+ * if pgid != pid
+ *     there must exist some pid in same session having pgid (EPERM)
+ * pid must not be session leader (EPERM)
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct setpgid_args {
+       int     pid;            /* target process id */
+       int     pgid;           /* target pgrp id */
+};
+#endif
+/* ARGSUSED */
+int
+sys_setpgid(struct thread *td, struct setpgid_args *uap)
+{
+       struct proc *curp = td->td_proc;
+       struct proc *targp;     /* target process */
+       struct pgrp *pgrp;      /* target pgrp */
+       int error;
+       struct pgrp *newpgrp;
+
+       if (uap->pgid < 0)
+               return (EINVAL);
+
+       error = 0;
+
+       newpgrp = malloc(sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO);
+
+       sx_xlock(&proctree_lock);
+       if (uap->pid != 0 && uap->pid != curp->p_pid) {
+               if ((targp = pfind(uap->pid)) == NULL) {
+                       error = ESRCH;
+                       goto done;
+               }
+               if (!inferior(targp)) {
+                       PROC_UNLOCK(targp);
+                       error = ESRCH;
+                       goto done;
+               }
+               if ((error = p_cansee(td, targp))) {
+                       PROC_UNLOCK(targp);
+                       goto done;
+               }
+               if (targp->p_pgrp == NULL ||
+                   targp->p_session != curp->p_session) {
+                       PROC_UNLOCK(targp);
+                       error = EPERM;
+                       goto done;
+               }
+               if (targp->p_flag & P_EXEC) {
+                       PROC_UNLOCK(targp);
+                       error = EACCES;
+                       goto done;
+               }
+               PROC_UNLOCK(targp);
+       } else
+               targp = curp;
+       if (SESS_LEADER(targp)) {
+               error = EPERM;
+               goto done;
+       }
+       if (uap->pgid == 0)
+               uap->pgid = targp->p_pid;
+       if ((pgrp = pgfind(uap->pgid)) == NULL) {
+               if (uap->pgid == targp->p_pid) {
+                       error = enterpgrp(targp, uap->pgid, newpgrp,
+                           NULL);
+                       if (error == 0)
+                               newpgrp = NULL;
+               } else
+                       error = EPERM;
+       } else {
+               if (pgrp == targp->p_pgrp) {
+                       PGRP_UNLOCK(pgrp);
+                       goto done;
+               }
+               if (pgrp->pg_id != targp->p_pid &&
+                   pgrp->pg_session != curp->p_session) {
+                       PGRP_UNLOCK(pgrp);
+                       error = EPERM;
+                       goto done;
+               }
+               PGRP_UNLOCK(pgrp);
+               error = enterthispgrp(targp, pgrp);
+       }
+done:
+       sx_xunlock(&proctree_lock);
+       KASSERT((error == 0) || (newpgrp != NULL),
+           ("setpgid failed and newpgrp is NULL"));
+       if (newpgrp != NULL)
+               free(newpgrp, M_PGRP);
+       return (error);
+}
+
+/*
+ * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD
+ * compatible.  It says that setting the uid/gid to euid/egid is a special
+ * case of "appropriate privilege".  Once the rules are expanded out, this
+ * basically means that setuid(nnn) sets all three id's, in all permitted
+ * cases unless _POSIX_SAVED_IDS is enabled.  In that case, setuid(getuid())
+ * does not set the saved id - this is dangerous for traditional BSD
+ * programs.  For this reason, we *really* do not want to set
+ * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2.
+ */
+#define POSIX_APPENDIX_B_4_2_2
+
+#ifndef _SYS_SYSPROTO_H_
+struct setuid_args {
+       uid_t   uid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setuid(struct thread *td, struct setuid_args *uap)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       uid_t uid;
+       struct uidinfo *uip;
+       int error;
+
+       uid = uap->uid;
+       AUDIT_ARG_UID(uid);
+       newcred = crget();
+       uip = uifind(uid);
+       PROC_LOCK(p);
+       /*
+        * Copy credentials so other references do not see our changes.
+        */
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_setuid(oldcred, uid);
+       if (error)
+               goto fail;
+#endif
+
+       /*
+        * See if we have "permission" by POSIX 1003.1 rules.
+        *
+        * Note that setuid(geteuid()) is a special case of
+        * "appropriate privileges" in appendix B.4.2.2.  We need
+        * to use this clause to be compatible with traditional BSD
+        * semantics.  Basically, it means that "setuid(xx)" sets all
+        * three id's (assuming you have privs).
+        *
+        * Notes on the logic.  We do things in three steps.
+        * 1: We determine if the euid is going to change, and do EPERM
+        *    right away.  We unconditionally change the euid later if this
+        *    test is satisfied, simplifying that part of the logic.
+        * 2: We determine if the real and/or saved uids are going to
+        *    change.  Determined by compile options.
+        * 3: Change euid last. (after tests in #2 for "appropriate privs")
+        */
+       if (uid != oldcred->cr_ruid &&          /* allow setuid(getuid()) */
+#ifdef _POSIX_SAVED_IDS
+           uid != oldcred->cr_svuid &&         /* allow setuid(saved gid) */
+#endif
+#ifdef POSIX_APPENDIX_B_4_2_2  /* Use BSD-compat clause from B.4.2.2 */
+           uid != oldcred->cr_uid &&           /* allow setuid(geteuid()) */
+#endif
+           (error = priv_check_cred(oldcred, PRIV_CRED_SETUID, 0)) != 0)
+               goto fail;
+
+#ifdef _POSIX_SAVED_IDS
+       /*
+        * Do we have "appropriate privileges" (are we root or uid == euid)
+        * If so, we are changing the real uid and/or saved uid.
+        */
+       if (
+#ifdef POSIX_APPENDIX_B_4_2_2  /* Use the clause from B.4.2.2 */
+           uid == oldcred->cr_uid ||
+#endif
+           /* We are using privs. */
+           priv_check_cred(oldcred, PRIV_CRED_SETUID, 0) == 0)
+#endif
+       {
+               /*
+                * Set the real uid and transfer proc count to new user.
+                */
+               if (uid != oldcred->cr_ruid) {
+                       change_ruid(newcred, uip);
+                       setsugid(p);
+               }
+               /*
+                * Set saved uid
+                *
+                * XXX always set saved uid even if not _POSIX_SAVED_IDS, as
+                * the security of seteuid() depends on it.  B.4.2.2 says it
+                * is important that we should do this.
+                */
+               if (uid != oldcred->cr_svuid) {
+                       change_svuid(newcred, uid);
+                       setsugid(p);
+               }
+       }
+
+       /*
+        * In all permitted cases, we are changing the euid.
+        */
+       if (uid != oldcred->cr_uid) {
+               change_euid(newcred, uip);
+               setsugid(p);
+       }
+       proc_set_cred(p, newcred);
+#ifdef RACCT
+       racct_proc_ucred_changed(p, oldcred, newcred);
+       crhold(newcred);
+#endif
+       PROC_UNLOCK(p);
+#ifdef RCTL
+       rctl_proc_ucred_changed(p, newcred);
+       crfree(newcred);
+#endif
+       uifree(uip);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       uifree(uip);
+       crfree(newcred);
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct seteuid_args {
+       uid_t   euid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_seteuid(struct thread *td, struct seteuid_args *uap)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       uid_t euid;
+       struct uidinfo *euip;
+       int error;
+
+       euid = uap->euid;
+       AUDIT_ARG_EUID(euid);
+       newcred = crget();
+       euip = uifind(euid);
+       PROC_LOCK(p);
+       /*
+        * Copy credentials so other references do not see our changes.
+        */
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_seteuid(oldcred, euid);
+       if (error)
+               goto fail;
+#endif
+
+       if (euid != oldcred->cr_ruid &&         /* allow seteuid(getuid()) */
+           euid != oldcred->cr_svuid &&        /* allow seteuid(saved uid) */
+           (error = priv_check_cred(oldcred, PRIV_CRED_SETEUID, 0)) != 0)
+               goto fail;
+
+       /*
+        * Everything's okay, do it.
+        */
+       if (oldcred->cr_uid != euid) {
+               change_euid(newcred, euip);
+               setsugid(p);
+       }
+       proc_set_cred(p, newcred);
+       PROC_UNLOCK(p);
+       uifree(euip);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       uifree(euip);
+       crfree(newcred);
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setgid_args {
+       gid_t   gid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setgid(struct thread *td, struct setgid_args *uap)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       gid_t gid;
+       int error;
+
+       gid = uap->gid;
+       AUDIT_ARG_GID(gid);
+       newcred = crget();
+       PROC_LOCK(p);
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_setgid(oldcred, gid);
+       if (error)
+               goto fail;
+#endif
+
+       /*
+        * See if we have "permission" by POSIX 1003.1 rules.
+        *
+        * Note that setgid(getegid()) is a special case of
+        * "appropriate privileges" in appendix B.4.2.2.  We need
+        * to use this clause to be compatible with traditional BSD
+        * semantics.  Basically, it means that "setgid(xx)" sets all
+        * three id's (assuming you have privs).
+        *
+        * For notes on the logic here, see setuid() above.
+        */
+       if (gid != oldcred->cr_rgid &&          /* allow setgid(getgid()) */
+#ifdef _POSIX_SAVED_IDS
+           gid != oldcred->cr_svgid &&         /* allow setgid(saved gid) */
+#endif
+#ifdef POSIX_APPENDIX_B_4_2_2  /* Use BSD-compat clause from B.4.2.2 */
+           gid != oldcred->cr_groups[0] && /* allow setgid(getegid()) */
+#endif
+           (error = priv_check_cred(oldcred, PRIV_CRED_SETGID, 0)) != 0)
+               goto fail;
+
+#ifdef _POSIX_SAVED_IDS
+       /*
+        * Do we have "appropriate privileges" (are we root or gid == egid)
+        * If so, we are changing the real uid and saved gid.
+        */
+       if (
+#ifdef POSIX_APPENDIX_B_4_2_2  /* use the clause from B.4.2.2 */
+           gid == oldcred->cr_groups[0] ||
+#endif
+           /* We are using privs. */
+           priv_check_cred(oldcred, PRIV_CRED_SETGID, 0) == 0)
+#endif
+       {
+               /*
+                * Set real gid
+                */
+               if (oldcred->cr_rgid != gid) {
+                       change_rgid(newcred, gid);
+                       setsugid(p);
+               }
+               /*
+                * Set saved gid
+                *
+                * XXX always set saved gid even if not _POSIX_SAVED_IDS, as
+                * the security of setegid() depends on it.  B.4.2.2 says it
+                * is important that we should do this.
+                */
+               if (oldcred->cr_svgid != gid) {
+                       change_svgid(newcred, gid);
+                       setsugid(p);
+               }
+       }
+       /*
+        * In all cases permitted cases, we are changing the egid.
+        * Copy credentials so other references do not see our changes.
+        */
+       if (oldcred->cr_groups[0] != gid) {
+               change_egid(newcred, gid);
+               setsugid(p);
+       }
+       proc_set_cred(p, newcred);
+       PROC_UNLOCK(p);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       crfree(newcred);
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setegid_args {
+       gid_t   egid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setegid(struct thread *td, struct setegid_args *uap)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       gid_t egid;
+       int error;
+
+       egid = uap->egid;
+       AUDIT_ARG_EGID(egid);
+       newcred = crget();
+       PROC_LOCK(p);
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_setegid(oldcred, egid);
+       if (error)
+               goto fail;
+#endif
+
+       if (egid != oldcred->cr_rgid &&         /* allow setegid(getgid()) */
+           egid != oldcred->cr_svgid &&        /* allow setegid(saved gid) */
+           (error = priv_check_cred(oldcred, PRIV_CRED_SETEGID, 0)) != 0)
+               goto fail;
+
+       if (oldcred->cr_groups[0] != egid) {
+               change_egid(newcred, egid);
+               setsugid(p);
+       }
+       proc_set_cred(p, newcred);
+       PROC_UNLOCK(p);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       crfree(newcred);
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setgroups_args {
+       u_int   gidsetsize;
+       gid_t   *gidset;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setgroups(struct thread *td, struct setgroups_args *uap)
+{
+       gid_t smallgroups[XU_NGROUPS];
+       gid_t *groups;
+       u_int gidsetsize;
+       int error;
+
+       gidsetsize = uap->gidsetsize;
+       if (gidsetsize > ngroups_max + 1)
+               return (EINVAL);
+
+       if (gidsetsize > XU_NGROUPS)
+               groups = malloc(gidsetsize * sizeof(gid_t), M_TEMP, M_WAITOK);
+       else
+               groups = smallgroups;
+
+       error = copyin(uap->gidset, groups, gidsetsize * sizeof(gid_t));
+       if (error == 0)
+               error = kern_setgroups(td, gidsetsize, groups);
+
+       if (gidsetsize > XU_NGROUPS)
+               free(groups, M_TEMP);
+       return (error);
+}
+
+int
+kern_setgroups(struct thread *td, u_int ngrp, gid_t *groups)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       int error;
+
+       MPASS(ngrp <= ngroups_max + 1);
+       AUDIT_ARG_GROUPSET(groups, ngrp);
+       newcred = crget();
+       crextend(newcred, ngrp);
+       PROC_LOCK(p);
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_setgroups(oldcred, ngrp, groups);
+       if (error)
+               goto fail;
+#endif
+
+       error = priv_check_cred(oldcred, PRIV_CRED_SETGROUPS, 0);
+       if (error)
+               goto fail;
+
+       if (ngrp == 0) {
+               /*
+                * setgroups(0, NULL) is a legitimate way of clearing the
+                * groups vector on non-BSD systems (which generally do not
+                * have the egid in the groups[0]).  We risk security holes
+                * when running non-BSD software if we do not do the same.
+                */
+               newcred->cr_ngroups = 1;
+       } else {
+               crsetgroups_locked(newcred, ngrp, groups);
+       }
+       setsugid(p);
+       proc_set_cred(p, newcred);
+       PROC_UNLOCK(p);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       crfree(newcred);
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setreuid_args {
+       uid_t   ruid;
+       uid_t   euid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setreuid(struct thread *td, struct setreuid_args *uap)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       uid_t euid, ruid;
+       struct uidinfo *euip, *ruip;
+       int error;
+
+       euid = uap->euid;
+       ruid = uap->ruid;
+       AUDIT_ARG_EUID(euid);
+       AUDIT_ARG_RUID(ruid);
+       newcred = crget();
+       euip = uifind(euid);
+       ruip = uifind(ruid);
+       PROC_LOCK(p);
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_setreuid(oldcred, ruid, euid);
+       if (error)
+               goto fail;
+#endif
+
+       if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid &&
+             ruid != oldcred->cr_svuid) ||
+            (euid != (uid_t)-1 && euid != oldcred->cr_uid &&
+             euid != oldcred->cr_ruid && euid != oldcred->cr_svuid)) &&
+           (error = priv_check_cred(oldcred, PRIV_CRED_SETREUID, 0)) != 0)
+               goto fail;
+
+       if (euid != (uid_t)-1 && oldcred->cr_uid != euid) {
+               change_euid(newcred, euip);
+               setsugid(p);
+       }
+       if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) {
+               change_ruid(newcred, ruip);
+               setsugid(p);
+       }
+       if ((ruid != (uid_t)-1 || newcred->cr_uid != newcred->cr_ruid) &&
+           newcred->cr_svuid != newcred->cr_uid) {
+               change_svuid(newcred, newcred->cr_uid);
+               setsugid(p);
+       }
+       proc_set_cred(p, newcred);
+#ifdef RACCT
+       racct_proc_ucred_changed(p, oldcred, newcred);
+       crhold(newcred);
+#endif
+       PROC_UNLOCK(p);
+#ifdef RCTL
+       rctl_proc_ucred_changed(p, newcred);
+       crfree(newcred);
+#endif
+       uifree(ruip);
+       uifree(euip);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       uifree(ruip);
+       uifree(euip);
+       crfree(newcred);
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setregid_args {
+       gid_t   rgid;
+       gid_t   egid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setregid(struct thread *td, struct setregid_args *uap)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       gid_t egid, rgid;
+       int error;
+
+       egid = uap->egid;
+       rgid = uap->rgid;
+       AUDIT_ARG_EGID(egid);
+       AUDIT_ARG_RGID(rgid);
+       newcred = crget();
+       PROC_LOCK(p);
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_setregid(oldcred, rgid, egid);
+       if (error)
+               goto fail;
+#endif
+
+       if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid &&
+           rgid != oldcred->cr_svgid) ||
+            (egid != (gid_t)-1 && egid != oldcred->cr_groups[0] &&
+            egid != oldcred->cr_rgid && egid != oldcred->cr_svgid)) &&
+           (error = priv_check_cred(oldcred, PRIV_CRED_SETREGID, 0)) != 0)
+               goto fail;
+
+       if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) {
+               change_egid(newcred, egid);
+               setsugid(p);
+       }
+       if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) {
+               change_rgid(newcred, rgid);
+               setsugid(p);
+       }
+       if ((rgid != (gid_t)-1 || newcred->cr_groups[0] != newcred->cr_rgid) &&
+           newcred->cr_svgid != newcred->cr_groups[0]) {
+               change_svgid(newcred, newcred->cr_groups[0]);
+               setsugid(p);
+       }
+       proc_set_cred(p, newcred);
+       PROC_UNLOCK(p);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       crfree(newcred);
+       return (error);
+}
+
+/*
+ * setresuid(ruid, euid, suid) is like setreuid except control over the saved
+ * uid is explicit.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct setresuid_args {
+       uid_t   ruid;
+       uid_t   euid;
+       uid_t   suid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setresuid(struct thread *td, struct setresuid_args *uap)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       uid_t euid, ruid, suid;
+       struct uidinfo *euip, *ruip;
+       int error;
+
+       euid = uap->euid;
+       ruid = uap->ruid;
+       suid = uap->suid;
+       AUDIT_ARG_EUID(euid);
+       AUDIT_ARG_RUID(ruid);
+       AUDIT_ARG_SUID(suid);
+       newcred = crget();
+       euip = uifind(euid);
+       ruip = uifind(ruid);
+       PROC_LOCK(p);
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_setresuid(oldcred, ruid, euid, suid);
+       if (error)
+               goto fail;
+#endif
+
+       if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid &&
+            ruid != oldcred->cr_svuid &&
+             ruid != oldcred->cr_uid) ||
+            (euid != (uid_t)-1 && euid != oldcred->cr_ruid &&
+           euid != oldcred->cr_svuid &&
+             euid != oldcred->cr_uid) ||
+            (suid != (uid_t)-1 && suid != oldcred->cr_ruid &&
+           suid != oldcred->cr_svuid &&
+             suid != oldcred->cr_uid)) &&
+           (error = priv_check_cred(oldcred, PRIV_CRED_SETRESUID, 0)) != 0)
+               goto fail;
+
+       if (euid != (uid_t)-1 && oldcred->cr_uid != euid) {
+               change_euid(newcred, euip);
+               setsugid(p);
+       }
+       if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) {
+               change_ruid(newcred, ruip);
+               setsugid(p);
+       }
+       if (suid != (uid_t)-1 && oldcred->cr_svuid != suid) {
+               change_svuid(newcred, suid);
+               setsugid(p);
+       }
+       proc_set_cred(p, newcred);
+#ifdef RACCT
+       racct_proc_ucred_changed(p, oldcred, newcred);
+       crhold(newcred);
+#endif
+       PROC_UNLOCK(p);
+#ifdef RCTL
+       rctl_proc_ucred_changed(p, newcred);
+       crfree(newcred);
+#endif
+       uifree(ruip);
+       uifree(euip);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       uifree(ruip);
+       uifree(euip);
+       crfree(newcred);
+       return (error);
+
+}
+
+/*
+ * setresgid(rgid, egid, sgid) is like setregid except control over the saved
+ * gid is explicit.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct setresgid_args {
+       gid_t   rgid;
+       gid_t   egid;
+       gid_t   sgid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setresgid(struct thread *td, struct setresgid_args *uap)
+{
+       struct proc *p = td->td_proc;
+       struct ucred *newcred, *oldcred;
+       gid_t egid, rgid, sgid;
+       int error;
+
+       egid = uap->egid;
+       rgid = uap->rgid;
+       sgid = uap->sgid;
+       AUDIT_ARG_EGID(egid);
+       AUDIT_ARG_RGID(rgid);
+       AUDIT_ARG_SGID(sgid);
+       newcred = crget();
+       PROC_LOCK(p);
+       oldcred = crcopysafe(p, newcred);
+
+#ifdef MAC
+       error = mac_cred_check_setresgid(oldcred, rgid, egid, sgid);
+       if (error)
+               goto fail;
+#endif
+
+       if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid &&
+             rgid != oldcred->cr_svgid &&
+             rgid != oldcred->cr_groups[0]) ||
+            (egid != (gid_t)-1 && egid != oldcred->cr_rgid &&
+             egid != oldcred->cr_svgid &&
+             egid != oldcred->cr_groups[0]) ||
+            (sgid != (gid_t)-1 && sgid != oldcred->cr_rgid &&
+             sgid != oldcred->cr_svgid &&
+             sgid != oldcred->cr_groups[0])) &&
+           (error = priv_check_cred(oldcred, PRIV_CRED_SETRESGID, 0)) != 0)
+               goto fail;
+
+       if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) {
+               change_egid(newcred, egid);
+               setsugid(p);
+       }
+       if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) {
+               change_rgid(newcred, rgid);
+               setsugid(p);
+       }
+       if (sgid != (gid_t)-1 && oldcred->cr_svgid != sgid) {
+               change_svgid(newcred, sgid);
+               setsugid(p);
+       }
+       proc_set_cred(p, newcred);
+       PROC_UNLOCK(p);
+       crfree(oldcred);
+       return (0);
+
+fail:
+       PROC_UNLOCK(p);
+       crfree(newcred);
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getresuid_args {
+       uid_t   *ruid;
+       uid_t   *euid;
+       uid_t   *suid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getresuid(struct thread *td, struct getresuid_args *uap)
+{
+       struct ucred *cred;
+       int error1 = 0, error2 = 0, error3 = 0;
+
+       cred = td->td_ucred;
+       if (uap->ruid)
+               error1 = copyout(&cred->cr_ruid,
+                   uap->ruid, sizeof(cred->cr_ruid));
+       if (uap->euid)
+               error2 = copyout(&cred->cr_uid,
+                   uap->euid, sizeof(cred->cr_uid));
+       if (uap->suid)
+               error3 = copyout(&cred->cr_svuid,
+                   uap->suid, sizeof(cred->cr_svuid));
+       return (error1 ? error1 : error2 ? error2 : error3);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getresgid_args {
+       gid_t   *rgid;
+       gid_t   *egid;
+       gid_t   *sgid;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getresgid(struct thread *td, struct getresgid_args *uap)
+{
+       struct ucred *cred;
+       int error1 = 0, error2 = 0, error3 = 0;
+
+       cred = td->td_ucred;
+       if (uap->rgid)
+               error1 = copyout(&cred->cr_rgid,
+                   uap->rgid, sizeof(cred->cr_rgid));
+       if (uap->egid)
+               error2 = copyout(&cred->cr_groups[0],
+                   uap->egid, sizeof(cred->cr_groups[0]));
+       if (uap->sgid)
+               error3 = copyout(&cred->cr_svgid,
+                   uap->sgid, sizeof(cred->cr_svgid));
+       return (error1 ? error1 : error2 ? error2 : error3);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct issetugid_args {
+       int dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_issetugid(struct thread *td, struct issetugid_args *uap)
+{
+       struct proc *p = td->td_proc;
+
+       /*
+        * Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
+        * we use P_SUGID because we consider changing the owners as
+        * "tainting" as well.
+        * This is significant for procs that start as root and "become"
+        * a user without an exec - programs cannot know *everything*
+        * that libc *might* have put in their data segment.
+        */
+       td->td_retval[0] = (p->p_flag & P_SUGID) ? 1 : 0;
+       return (0);
+}
+
+int
+sys___setugid(struct thread *td, struct __setugid_args *uap)
+{
+#ifdef REGRESSION
+       struct proc *p;
+
+       p = td->td_proc;
+       switch (uap->flag) {
+       case 0:
+               PROC_LOCK(p);
+               p->p_flag &= ~P_SUGID;
+               PROC_UNLOCK(p);
+               return (0);
+       case 1:
+               PROC_LOCK(p);
+               p->p_flag |= P_SUGID;
+               PROC_UNLOCK(p);
+               return (0);
+       default:
+               return (EINVAL);
+       }
+#else /* !REGRESSION */
+
+       return (ENOSYS);
+#endif /* REGRESSION */
+}
+
+/*
+ * Check if gid is a member of the group set.
+ */
+int
+groupmember(gid_t gid, struct ucred *cred)
+{
+       int l;
+       int h;
+       int m;
+
+       if (cred->cr_groups[0] == gid)
+               return(1);
+
+       /*
+        * If gid was not our primary group, perform a binary search
+        * of the supplemental groups.  This is possible because we
+        * sort the groups in crsetgroups().
+        */
+       l = 1;
+       h = cred->cr_ngroups;
+       while (l < h) {
+               m = l + ((h - l) / 2);
+               if (cred->cr_groups[m] < gid)
+                       l = m + 1; 
+               else
+                       h = m; 
+       }
+       if ((l < cred->cr_ngroups) && (cred->cr_groups[l] == gid))
+               return (1);
+
+       return (0);
+}
+
+/*
+ * Test the active securelevel against a given level.  securelevel_gt()
+ * implements (securelevel > level).  securelevel_ge() implements
+ * (securelevel >= level).  Note that the logic is inverted -- these
+ * functions return EPERM on "success" and 0 on "failure".
+ *
+ * Due to care taken when setting the securelevel, we know that no jail will
+ * be less secure that its parent (or the physical system), so it is sufficient
+ * to test the current jail only.
+ *
+ * XXXRW: Possibly since this has to do with privilege, it should move to
+ * kern_priv.c.
+ */
+int
+securelevel_gt(struct ucred *cr, int level)
+{
+
+       return (cr->cr_prison->pr_securelevel > level ? EPERM : 0);
+}
+
+int
+securelevel_ge(struct ucred *cr, int level)
+{
+
+       return (cr->cr_prison->pr_securelevel >= level ? EPERM : 0);
+}
+
+/*
+ * 'see_other_uids' determines whether or not visibility of processes
+ * and sockets with credentials holding different real uids is possible
+ * using a variety of system MIBs.
+ * XXX: data declarations should be together near the beginning of the file.
+ */
+static int     see_other_uids = 1;
+SYSCTL_INT(_security_bsd, OID_AUTO, see_other_uids, CTLFLAG_RW,
+    &see_other_uids, 0,
+    "Unprivileged processes may see subjects/objects with different real uid");
+
+/*-
+ * Determine if u1 "can see" the subject specified by u2, according to the
+ * 'see_other_uids' policy.
+ * Returns: 0 for permitted, ESRCH otherwise
+ * Locks: none
+ * References: *u1 and *u2 must not change during the call
+ *             u1 may equal u2, in which case only one reference is required
+ */
+int
+cr_canseeotheruids(struct ucred *u1, struct ucred *u2)
+{
+
+       if (!see_other_uids && u1->cr_ruid != u2->cr_ruid) {
+               if (priv_check_cred(u1, PRIV_SEEOTHERUIDS, 0) != 0)
+                       return (ESRCH);
+       }
+       return (0);
+}
+
+/*
+ * 'see_other_gids' determines whether or not visibility of processes
+ * and sockets with credentials holding different real gids is possible
+ * using a variety of system MIBs.
+ * XXX: data declarations should be together near the beginning of the file.
+ */
+static int     see_other_gids = 1;
+SYSCTL_INT(_security_bsd, OID_AUTO, see_other_gids, CTLFLAG_RW,
+    &see_other_gids, 0,
+    "Unprivileged processes may see subjects/objects with different real gid");
+
+/*
+ * Determine if u1 can "see" the subject specified by u2, according to the
+ * 'see_other_gids' policy.
+ * Returns: 0 for permitted, ESRCH otherwise
+ * Locks: none
+ * References: *u1 and *u2 must not change during the call
+ *             u1 may equal u2, in which case only one reference is required
+ */
+int
+cr_canseeothergids(struct ucred *u1, struct ucred *u2)
+{
+       int i, match;
+       
+       if (!see_other_gids) {
+               match = 0;
+               for (i = 0; i < u1->cr_ngroups; i++) {
+                       if (groupmember(u1->cr_groups[i], u2))
+                               match = 1;
+                       if (match)
+                               break;
+               }
+               if (!match) {
+                       if (priv_check_cred(u1, PRIV_SEEOTHERGIDS, 0) != 0)
+                               return (ESRCH);
+               }
+       }
+       return (0);
+}
+
+/*
+ * 'see_jail_proc' determines whether or not visibility of processes and
+ * sockets with credentials holding different jail ids is possible using a
+ * variety of system MIBs.
+ *
+ * XXX: data declarations should be together near the beginning of the file.
+ */
+
+static int     see_jail_proc = 1;
+SYSCTL_INT(_security_bsd, OID_AUTO, see_jail_proc, CTLFLAG_RW,
+    &see_jail_proc, 0,
+    "Unprivileged processes may see subjects/objects with different jail ids");
+
+/*-
+ * Determine if u1 "can see" the subject specified by u2, according to the
+ * 'see_jail_proc' policy.
+ * Returns: 0 for permitted, ESRCH otherwise
+ * Locks: none
+ * References: *u1 and *u2 must not change during the call
+ *             u1 may equal u2, in which case only one reference is required
+ */
+int
+cr_canseejailproc(struct ucred *u1, struct ucred *u2)
+{
+       if (u1->cr_uid == 0)
+               return (0);
+       return (!see_jail_proc && u1->cr_prison != u2->cr_prison ? ESRCH : 0);
+}
+
+/*-
+ * Determine if u1 "can see" the subject specified by u2.
+ * Returns: 0 for permitted, an errno value otherwise
+ * Locks: none
+ * References: *u1 and *u2 must not change during the call
+ *             u1 may equal u2, in which case only one reference is required
+ */
+int
+cr_cansee(struct ucred *u1, struct ucred *u2)
+{
+       int error;
+
+       if ((error = prison_check(u1, u2)))
+               return (error);
+#ifdef MAC
+       if ((error = mac_cred_check_visible(u1, u2)))
+               return (error);
+#endif
+       if ((error = cr_canseeotheruids(u1, u2)))
+               return (error);
+       if ((error = cr_canseeothergids(u1, u2)))
+               return (error);
+       if ((error = cr_canseejailproc(u1, u2)))
+               return (error);
+       return (0);
+}
+
+/*-
+ * Determine if td "can see" the subject specified by p.
+ * Returns: 0 for permitted, an errno value otherwise
+ * Locks: Sufficient locks to protect p->p_ucred must be held.  td really
+ *        should be curthread.
+ * References: td and p must be valid for the lifetime of the call
+ */
+int
+p_cansee(struct thread *td, struct proc *p)
+{
+
+       /* Wrap cr_cansee() for all functionality. */
+       KASSERT(td == curthread, ("%s: td not curthread", __func__));
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       return (cr_cansee(td->td_ucred, p->p_ucred));
+}
+
+/*
+ * 'conservative_signals' prevents the delivery of a broad class of
+ * signals by unprivileged processes to processes that have changed their
+ * credentials since the last invocation of execve().  This can prevent
+ * the leakage of cached information or retained privileges as a result
+ * of a common class of signal-related vulnerabilities.  However, this
+ * may interfere with some applications that expect to be able to
+ * deliver these signals to peer processes after having given up
+ * privilege.
+ */
+static int     conservative_signals = 1;
+SYSCTL_INT(_security_bsd, OID_AUTO, conservative_signals, CTLFLAG_RW,
+    &conservative_signals, 0, "Unprivileged processes prevented from "
+    "sending certain signals to processes whose credentials have changed");
+/*-
+ * Determine whether cred may deliver the specified signal to proc.
+ * Returns: 0 for permitted, an errno value otherwise.
+ * Locks: A lock must be held for proc.
+ * References: cred and proc must be valid for the lifetime of the call.
+ */
+int
+cr_cansignal(struct ucred *cred, struct proc *proc, int signum)
+{
+       int error;
+
+       PROC_LOCK_ASSERT(proc, MA_OWNED);
+       /*
+        * Jail semantics limit the scope of signalling to proc in the
+        * same jail as cred, if cred is in jail.
+        */
+       error = prison_check(cred, proc->p_ucred);
+       if (error)
+               return (error);
+#ifdef MAC
+       if ((error = mac_proc_check_signal(cred, proc, signum)))
+               return (error);
+#endif
+       if ((error = cr_canseeotheruids(cred, proc->p_ucred)))
+               return (error);
+       if ((error = cr_canseeothergids(cred, proc->p_ucred)))
+               return (error);
+
+       /*
+        * UNIX signal semantics depend on the status of the P_SUGID
+        * bit on the target process.  If the bit is set, then additional
+        * restrictions are placed on the set of available signals.
+        */
+       if (conservative_signals && (proc->p_flag & P_SUGID)) {
+               switch (signum) {
+               case 0:
+               case SIGKILL:
+               case SIGINT:
+               case SIGTERM:
+               case SIGALRM:
+               case SIGSTOP:
+               case SIGTTIN:
+               case SIGTTOU:
+               case SIGTSTP:
+               case SIGHUP:
+               case SIGUSR1:
+               case SIGUSR2:
+                       /*
+                        * Generally, permit job and terminal control
+                        * signals.
+                        */
+                       break;
+               default:
+                       /* Not permitted without privilege. */
+                       error = priv_check_cred(cred, PRIV_SIGNAL_SUGID, 0);
+                       if (error)
+                               return (error);
+               }
+       }
+
+       /*
+        * Generally, the target credential's ruid or svuid must match the
+        * subject credential's ruid or euid.
+        */
+       if (cred->cr_ruid != proc->p_ucred->cr_ruid &&
+           cred->cr_ruid != proc->p_ucred->cr_svuid &&
+           cred->cr_uid != proc->p_ucred->cr_ruid &&
+           cred->cr_uid != proc->p_ucred->cr_svuid) {
+               error = priv_check_cred(cred, PRIV_SIGNAL_DIFFCRED, 0);
+               if (error)
+                       return (error);
+       }
+
+       return (0);
+}
+
+/*-
+ * Determine whether td may deliver the specified signal to p.
+ * Returns: 0 for permitted, an errno value otherwise
+ * Locks: Sufficient locks to protect various components of td and p
+ *        must be held.  td must be curthread, and a lock must be
+ *        held for p.
+ * References: td and p must be valid for the lifetime of the call
+ */
+int
+p_cansignal(struct thread *td, struct proc *p, int signum)
+{
+
+       KASSERT(td == curthread, ("%s: td not curthread", __func__));
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       if (td->td_proc == p)
+               return (0);
+
+       /*
+        * UNIX signalling semantics require that processes in the same
+        * session always be able to deliver SIGCONT to one another,
+        * overriding the remaining protections.
+        */
+       /* XXX: This will require an additional lock of some sort. */
+       if (signum == SIGCONT && td->td_proc->p_session == p->p_session)
+               return (0);
+       /*
+        * Some compat layers use SIGTHR and higher signals for
+        * communication between different kernel threads of the same
+        * process, so that they expect that it's always possible to
+        * deliver them, even for suid applications where cr_cansignal() can
+        * deny such ability for security consideration.  It should be
+        * pretty safe to do since the only way to create two processes
+        * with the same p_leader is via rfork(2).
+        */
+       if (td->td_proc->p_leader != NULL && signum >= SIGTHR &&
+           signum < SIGTHR + 4 && td->td_proc->p_leader == p->p_leader)
+               return (0);
+
+       return (cr_cansignal(td->td_ucred, p, signum));
+}
+
+/*-
+ * Determine whether td may reschedule p.
+ * Returns: 0 for permitted, an errno value otherwise
+ * Locks: Sufficient locks to protect various components of td and p
+ *        must be held.  td must be curthread, and a lock must
+ *        be held for p.
+ * References: td and p must be valid for the lifetime of the call
+ */
+int
+p_cansched(struct thread *td, struct proc *p)
+{
+       int error;
+
+       KASSERT(td == curthread, ("%s: td not curthread", __func__));
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       if (td->td_proc == p)
+               return (0);
+       if ((error = prison_check(td->td_ucred, p->p_ucred)))
+               return (error);
+#ifdef MAC
+       if ((error = mac_proc_check_sched(td->td_ucred, p)))
+               return (error);
+#endif
+       if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred)))
+               return (error);
+       if ((error = cr_canseeothergids(td->td_ucred, p->p_ucred)))
+               return (error);
+       if (td->td_ucred->cr_ruid != p->p_ucred->cr_ruid &&
+           td->td_ucred->cr_uid != p->p_ucred->cr_ruid) {
+               error = priv_check(td, PRIV_SCHED_DIFFCRED);
+               if (error)
+                       return (error);
+       }
+       return (0);
+}
+
+/*
+ * The 'unprivileged_proc_debug' flag may be used to disable a variety of
+ * unprivileged inter-process debugging services, including some procfs
+ * functionality, ptrace(), and ktrace().  In the past, inter-process
+ * debugging has been involved in a variety of security problems, and sites
+ * not requiring the service might choose to disable it when hardening
+ * systems.
+ *
+ * XXX: Should modifying and reading this variable require locking?
+ * XXX: data declarations should be together near the beginning of the file.
+ */
+static int     unprivileged_proc_debug = 1;
+SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_proc_debug, CTLFLAG_RW,
+    &unprivileged_proc_debug, 0,
+    "Unprivileged processes may use process debugging facilities");
+
+/*-
+ * Determine whether td may debug p.
+ * Returns: 0 for permitted, an errno value otherwise
+ * Locks: Sufficient locks to protect various components of td and p
+ *        must be held.  td must be curthread, and a lock must
+ *        be held for p.
+ * References: td and p must be valid for the lifetime of the call
+ */
+int
+p_candebug(struct thread *td, struct proc *p)
+{
+       int credentialchanged, error, grpsubset, i, uidsubset;
+
+       KASSERT(td == curthread, ("%s: td not curthread", __func__));
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       if (!unprivileged_proc_debug) {
+               error = priv_check(td, PRIV_DEBUG_UNPRIV);
+               if (error)
+                       return (error);
+       }
+       if (td->td_proc == p)
+               return (0);
+       if ((error = prison_check(td->td_ucred, p->p_ucred)))
+               return (error);
+#ifdef MAC
+       if ((error = mac_proc_check_debug(td->td_ucred, p)))
+               return (error);
+#endif
+       if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred)))
+               return (error);
+       if ((error = cr_canseeothergids(td->td_ucred, p->p_ucred)))
+               return (error);
+
+       /*
+        * Is p's group set a subset of td's effective group set?  This
+        * includes p's egid, group access list, rgid, and svgid.
+        */
+       grpsubset = 1;
+       for (i = 0; i < p->p_ucred->cr_ngroups; i++) {
+               if (!groupmember(p->p_ucred->cr_groups[i], td->td_ucred)) {
+                       grpsubset = 0;
+                       break;
+               }
+       }
+       grpsubset = grpsubset &&
+           groupmember(p->p_ucred->cr_rgid, td->td_ucred) &&
+           groupmember(p->p_ucred->cr_svgid, td->td_ucred);
+
+       /*
+        * Are the uids present in p's credential equal to td's
+        * effective uid?  This includes p's euid, svuid, and ruid.
+        */
+       uidsubset = (td->td_ucred->cr_uid == p->p_ucred->cr_uid &&
+           td->td_ucred->cr_uid == p->p_ucred->cr_svuid &&
+           td->td_ucred->cr_uid == p->p_ucred->cr_ruid);
+
+       /*
+        * Has the credential of the process changed since the last exec()?
+        */
+       credentialchanged = (p->p_flag & P_SUGID);
+
+       /*
+        * If p's gids aren't a subset, or the uids aren't a subset,
+        * or the credential has changed, require appropriate privilege
+        * for td to debug p.
+        */
+       if (!grpsubset || !uidsubset) {
+               error = priv_check(td, PRIV_DEBUG_DIFFCRED);
+               if (error)
+                       return (error);
+       }
+
+       if (credentialchanged) {
+               error = priv_check(td, PRIV_DEBUG_SUGID);
+               if (error)
+                       return (error);
+       }
+
+       /* Can't trace init when securelevel > 0. */
+       if (p == initproc) {
+               error = securelevel_gt(td->td_ucred, 0);
+               if (error)
+                       return (error);
+       }
+
+       /*
+        * Can't trace a process that's currently exec'ing.
+        *
+        * XXX: Note, this is not a security policy decision, it's a
+        * basic correctness/functionality decision.  Therefore, this check
+        * should be moved to the caller's of p_candebug().
+        */
+       if ((p->p_flag & P_INEXEC) != 0)
+               return (EBUSY);
+
+       /* Denied explicitely */
+       if ((p->p_flag2 & P2_NOTRACE) != 0) {
+               error = priv_check(td, PRIV_DEBUG_DENIED);
+               if (error != 0)
+                       return (error);
+       }
+
+       return (0);
+}
+
+/*-
+ * Determine whether the subject represented by cred can "see" a socket.
+ * Returns: 0 for permitted, ENOENT otherwise.
+ */
+int
+cr_canseesocket(struct ucred *cred, struct socket *so)
+{
+       int error;
+
+       error = prison_check(cred, so->so_cred);
+       if (error)
+               return (ENOENT);
+#ifdef MAC
+       error = mac_socket_check_visible(cred, so);
+       if (error)
+               return (error);
+#endif
+       if (cr_canseeotheruids(cred, so->so_cred))
+               return (ENOENT);
+       if (cr_canseeothergids(cred, so->so_cred))
+               return (ENOENT);
+
+       return (0);
+}
+
+/*-
+ * Determine whether td can wait for the exit of p.
+ * Returns: 0 for permitted, an errno value otherwise
+ * Locks: Sufficient locks to protect various components of td and p
+ *        must be held.  td must be curthread, and a lock must
+ *        be held for p.
+ * References: td and p must be valid for the lifetime of the call
+
+ */
+int
+p_canwait(struct thread *td, struct proc *p)
+{
+       int error;
+
+       KASSERT(td == curthread, ("%s: td not curthread", __func__));
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       if ((error = prison_check(td->td_ucred, p->p_ucred)))
+               return (error);
+#ifdef MAC
+       if ((error = mac_proc_check_wait(td->td_ucred, p)))
+               return (error);
+#endif
+#if 0
+       /* XXXMAC: This could have odd effects on some shells. */
+       if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred)))
+               return (error);
+#endif
+
+       return (0);
+}
+
+/*
+ * Allocate a zeroed cred structure.
+ */
+struct ucred *
+crget(void)
+{
+       struct ucred *cr;
+
+       cr = malloc(sizeof(*cr), M_CRED, M_WAITOK | M_ZERO);
+       refcount_init(&cr->cr_ref, 1);
+#ifdef AUDIT
+       audit_cred_init(cr);
+#endif
+#ifdef MAC
+       mac_cred_init(cr);
+#endif
+       cr->cr_groups = cr->cr_smallgroups;
+       cr->cr_agroups =
+           sizeof(cr->cr_smallgroups) / sizeof(cr->cr_smallgroups[0]);
+       return (cr);
+}
+
+/*
+ * Claim another reference to a ucred structure.
+ */
+struct ucred *
+crhold(struct ucred *cr)
+{
+
+       refcount_acquire(&cr->cr_ref);
+       return (cr);
+}
+
+/*
+ * Free a cred structure.  Throws away space when ref count gets to 0.
+ */
+void
+crfree(struct ucred *cr)
+{
+
+       KASSERT(cr->cr_ref > 0, ("bad ucred refcount: %d", cr->cr_ref));
+       KASSERT(cr->cr_ref != 0xdeadc0de, ("dangling reference to ucred"));
+       if (refcount_release(&cr->cr_ref)) {
+               /*
+                * Some callers of crget(), such as nfs_statfs(),
+                * allocate a temporary credential, but don't
+                * allocate a uidinfo structure.
+                */
+               if (cr->cr_uidinfo != NULL)
+                       uifree(cr->cr_uidinfo);
+               if (cr->cr_ruidinfo != NULL)
+                       uifree(cr->cr_ruidinfo);
+               /*
+                * Free a prison, if any.
+                */
+               if (cr->cr_prison != NULL)
+                       prison_free(cr->cr_prison);
+               if (cr->cr_loginclass != NULL)
+                       loginclass_free(cr->cr_loginclass);
+#ifdef AUDIT
+               audit_cred_destroy(cr);
+#endif
+#ifdef MAC
+               mac_cred_destroy(cr);
+#endif
+               if (cr->cr_groups != cr->cr_smallgroups)
+                       free(cr->cr_groups, M_CRED);
+               free(cr, M_CRED);
+       }
+}
+
+/*
+ * Copy a ucred's contents from a template.  Does not block.
+ */
+void
+crcopy(struct ucred *dest, struct ucred *src)
+{
+
+       KASSERT(dest->cr_ref == 1, ("crcopy of shared ucred"));
+       bcopy(&src->cr_startcopy, &dest->cr_startcopy,
+           (unsigned)((caddr_t)&src->cr_endcopy -
+               (caddr_t)&src->cr_startcopy));
+       crsetgroups(dest, src->cr_ngroups, src->cr_groups);
+       uihold(dest->cr_uidinfo);
+       uihold(dest->cr_ruidinfo);
+       prison_hold(dest->cr_prison);
+       loginclass_hold(dest->cr_loginclass);
+#ifdef AUDIT
+       audit_cred_copy(src, dest);
+#endif
+#ifdef MAC
+       mac_cred_copy(src, dest);
+#endif
+}
+
+/*
+ * Dup cred struct to a new held one.
+ */
+struct ucred *
+crdup(struct ucred *cr)
+{
+       struct ucred *newcr;
+
+       newcr = crget();
+       crcopy(newcr, cr);
+       return (newcr);
+}
+
+/*
+ * Fill in a struct xucred based on a struct ucred.
+ */
+void
+cru2x(struct ucred *cr, struct xucred *xcr)
+{
+       int ngroups;
+
+       bzero(xcr, sizeof(*xcr));
+       xcr->cr_version = XUCRED_VERSION;
+       xcr->cr_uid = cr->cr_uid;
+
+       ngroups = MIN(cr->cr_ngroups, XU_NGROUPS);
+       xcr->cr_ngroups = ngroups;
+       bcopy(cr->cr_groups, xcr->cr_groups,
+           ngroups * sizeof(*cr->cr_groups));
+}
+
+/*
+ * Set initial process credentials.
+ * Callers are responsible for providing the reference for provided 
credentials.
+ */
+void
+proc_set_cred_init(struct proc *p, struct ucred *newcred)
+{
+
+       p->p_ucred = newcred;
+}
+
+/*
+ * Change process credentials.
+ * Callers are responsible for providing the reference for passed credentials
+ * and for freeing old ones.
+ *
+ * Process has to be locked except when it does not have credentials (as it
+ * should not be visible just yet) or when newcred is NULL (as this can be
+ * only used when the process is about to be freed, at which point it should
+ * not be visible anymore).
+ */
+struct ucred *
+proc_set_cred(struct proc *p, struct ucred *newcred)
+{
+       struct ucred *oldcred;
+
+       MPASS(p->p_ucred != NULL);
+       if (newcred == NULL)
+               MPASS(p->p_state == PRS_ZOMBIE);
+       else
+               PROC_LOCK_ASSERT(p, MA_OWNED);
+
+       oldcred = p->p_ucred;
+       p->p_ucred = newcred;
+       if (newcred != NULL)
+               PROC_UPDATE_COW(p);
+       return (oldcred);
+}
+
+struct ucred *
+crcopysafe(struct proc *p, struct ucred *cr)
+{
+       struct ucred *oldcred;
+       int groups;
+
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+
+       oldcred = p->p_ucred;
+       while (cr->cr_agroups < oldcred->cr_agroups) {
+               groups = oldcred->cr_agroups;
+               PROC_UNLOCK(p);
+               crextend(cr, groups);
+               PROC_LOCK(p);
+               oldcred = p->p_ucred;
+       }
+       crcopy(cr, oldcred);
+
+       return (oldcred);
+}
+
+/*
+ * Extend the passed in credential to hold n items.
+ */
+void
+crextend(struct ucred *cr, int n)
+{
+       int cnt;
+
+       /* Truncate? */
+       if (n <= cr->cr_agroups)
+               return;
+
+       /*
+        * We extend by 2 each time since we're using a power of two
+        * allocator until we need enough groups to fill a page.
+        * Once we're allocating multiple pages, only allocate as many
+        * as we actually need.  The case of processes needing a
+        * non-power of two number of pages seems more likely than
+        * a real world process that adds thousands of groups one at a
+        * time.
+        */
+       if ( n < PAGE_SIZE / sizeof(gid_t) ) {
+               if (cr->cr_agroups == 0)
+                       cnt = MINALLOCSIZE / sizeof(gid_t);
+               else
+                       cnt = cr->cr_agroups * 2;
+
+               while (cnt < n)
+                       cnt *= 2;
+       } else
+               cnt = roundup2(n, PAGE_SIZE / sizeof(gid_t));
+
+       /* Free the old array. */
+       if (cr->cr_groups != cr->cr_smallgroups)
+               free(cr->cr_groups, M_CRED);
+
+       cr->cr_groups = malloc(cnt * sizeof(gid_t), M_CRED, M_WAITOK | M_ZERO);
+       cr->cr_agroups = cnt;
+}
+
+/*
+ * Copy groups in to a credential, preserving any necessary invariants.
+ * Currently this includes the sorting of all supplemental gids.
+ * crextend() must have been called before hand to ensure sufficient
+ * space is available.
+ */
+static void
+crsetgroups_locked(struct ucred *cr, int ngrp, gid_t *groups)
+{
+       int i;
+       int j;
+       gid_t g;
+       
+       KASSERT(cr->cr_agroups >= ngrp, ("cr_ngroups is too small"));
+
+       bcopy(groups, cr->cr_groups, ngrp * sizeof(gid_t));
+       cr->cr_ngroups = ngrp;
+
+       /*
+        * Sort all groups except cr_groups[0] to allow groupmember to
+        * perform a binary search.
+        *
+        * XXX: If large numbers of groups become common this should
+        * be replaced with shell sort like linux uses or possibly
+        * heap sort.
+        */
+       for (i = 2; i < ngrp; i++) {
+               g = cr->cr_groups[i];
+               for (j = i-1; j >= 1 && g < cr->cr_groups[j]; j--)
+                       cr->cr_groups[j + 1] = cr->cr_groups[j];
+               cr->cr_groups[j + 1] = g;
+       }
+}
+
+/*
+ * Copy groups in to a credential after expanding it if required.
+ * Truncate the list to (ngroups_max + 1) if it is too large.
+ */
+void
+crsetgroups(struct ucred *cr, int ngrp, gid_t *groups)
+{
+
+       if (ngrp > ngroups_max + 1)
+               ngrp = ngroups_max + 1;
+
+       crextend(cr, ngrp);
+       crsetgroups_locked(cr, ngrp, groups);
+}
+
+/*
+ * Get login name, if available.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct getlogin_args {
+       char    *namebuf;
+       u_int   namelen;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getlogin(struct thread *td, struct getlogin_args *uap)
+{
+       char login[MAXLOGNAME];
+       struct proc *p = td->td_proc;
+       size_t len;
+
+       if (uap->namelen > MAXLOGNAME)
+               uap->namelen = MAXLOGNAME;
+       PROC_LOCK(p);
+       SESS_LOCK(p->p_session);
+       len = strlcpy(login, p->p_session->s_login, uap->namelen) + 1;
+       SESS_UNLOCK(p->p_session);
+       PROC_UNLOCK(p);
+       if (len > uap->namelen)
+               return (ERANGE);
+       return (copyout(login, uap->namebuf, len));
+}
+
+/*
+ * Set login name.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct setlogin_args {
+       char    *namebuf;
+};
+#endif
+/* ARGSUSED */
+int
+sys_setlogin(struct thread *td, struct setlogin_args *uap)
+{
+       struct proc *p = td->td_proc;
+       int error;
+       char logintmp[MAXLOGNAME];
+
+       CTASSERT(sizeof(p->p_session->s_login) >= sizeof(logintmp));
+
+       error = priv_check(td, PRIV_PROC_SETLOGIN);
+       if (error)
+               return (error);
+       error = copyinstr(uap->namebuf, logintmp, sizeof(logintmp), NULL);
+       if (error != 0) {
+               if (error == ENAMETOOLONG)
+                       error = EINVAL;
+               return (error);
+       }
+       AUDIT_ARG_LOGIN(logintmp);
+       PROC_LOCK(p);
+       SESS_LOCK(p->p_session);
+       strcpy(p->p_session->s_login, logintmp);
+       SESS_UNLOCK(p->p_session);
+       PROC_UNLOCK(p);
+       return (0);
+}
+
+void
+setsugid(struct proc *p)
+{
+
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       p->p_flag |= P_SUGID;
+       if (!(p->p_pfsflags & PF_ISUGID))
+               p->p_stops = 0;
+}
+
+/*-
+ * Change a process's effective uid.
+ * Side effects: newcred->cr_uid and newcred->cr_uidinfo will be modified.
+ * References: newcred must be an exclusive credential reference for the
+ *             duration of the call.
+ */
+void
+change_euid(struct ucred *newcred, struct uidinfo *euip)
+{
+
+       newcred->cr_uid = euip->ui_uid;
+       uihold(euip);
+       uifree(newcred->cr_uidinfo);
+       newcred->cr_uidinfo = euip;
+}
+
+/*-
+ * Change a process's effective gid.
+ * Side effects: newcred->cr_gid will be modified.
+ * References: newcred must be an exclusive credential reference for the
+ *             duration of the call.
+ */
+void
+change_egid(struct ucred *newcred, gid_t egid)
+{
+
+       newcred->cr_groups[0] = egid;
+}
+
+/*-
+ * Change a process's real uid.
+ * Side effects: newcred->cr_ruid will be updated, newcred->cr_ruidinfo
+ *               will be updated, and the old and new cr_ruidinfo proc
+ *               counts will be updated.
+ * References: newcred must be an exclusive credential reference for the
+ *             duration of the call.
+ */
+void
+change_ruid(struct ucred *newcred, struct uidinfo *ruip)
+{
+
+       (void)chgproccnt(newcred->cr_ruidinfo, -1, 0);
+       newcred->cr_ruid = ruip->ui_uid;
+       uihold(ruip);
+       uifree(newcred->cr_ruidinfo);
+       newcred->cr_ruidinfo = ruip;
+       (void)chgproccnt(newcred->cr_ruidinfo, 1, 0);
+}
+
+/*-
+ * Change a process's real gid.
+ * Side effects: newcred->cr_rgid will be updated.
+ * References: newcred must be an exclusive credential reference for the
+ *             duration of the call.
+ */
+void
+change_rgid(struct ucred *newcred, gid_t rgid)
+{
+
+       newcred->cr_rgid = rgid;
+}
+
+/*-
+ * Change a process's saved uid.
+ * Side effects: newcred->cr_svuid will be updated.
+ * References: newcred must be an exclusive credential reference for the
+ *             duration of the call.
+ */
+void
+change_svuid(struct ucred *newcred, uid_t svuid)
+{
+
+       newcred->cr_svuid = svuid;
+}
+
+/*-
+ * Change a process's saved gid.
+ * Side effects: newcred->cr_svgid will be updated.
+ * References: newcred must be an exclusive credential reference for the
+ *             duration of the call.
+ */
+void
+change_svgid(struct ucred *newcred, gid_t svgid)
+{
+
+       newcred->cr_svgid = svgid;
+}
diff --git a/freebsd/sys/kern/kern_resource.c b/freebsd/sys/kern/kern_resource.c
new file mode 100644
index 00000000..49b1e0fe
--- /dev/null
+++ b/freebsd/sys/kern/kern_resource.c
@@ -0,0 +1,1539 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1982, 1986, 1991, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *     @(#)kern_resource.c     8.5 (Berkeley) 1/21/94
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/sysproto.h>
+#include <sys/file.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/mutex.h>
+#include <sys/priv.h>
+#include <sys/proc.h>
+#include <sys/refcount.h>
+#include <sys/racct.h>
+#include <sys/resourcevar.h>
+#include <sys/rwlock.h>
+#include <sys/sched.h>
+#include <sys/sx.h>
+#include <sys/syscallsubr.h>
+#include <sys/sysctl.h>
+#include <sys/sysent.h>
+#include <sys/time.h>
+#include <sys/umtx.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
+#include <vm/vm_map.h>
+
+
+static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures");
+static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
+#define        UIHASH(uid)     (&uihashtbl[(uid) & uihash])
+static struct rwlock uihashtbl_lock;
+static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
+static u_long uihash;          /* size of hash table - 1 */
+
+static void    calcru1(struct proc *p, struct rusage_ext *ruxp,
+                   struct timeval *up, struct timeval *sp);
+static int     donice(struct thread *td, struct proc *chgp, int n);
+static struct uidinfo *uilookup(uid_t uid);
+static void    ruxagg_locked(struct rusage_ext *rux, struct thread *td);
+
+/*
+ * Resource controls and accounting.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct getpriority_args {
+       int     which;
+       int     who;
+};
+#endif
+int
+sys_getpriority(struct thread *td, struct getpriority_args *uap)
+{
+       struct proc *p;
+       struct pgrp *pg;
+       int error, low;
+
+       error = 0;
+       low = PRIO_MAX + 1;
+       switch (uap->which) {
+
+       case PRIO_PROCESS:
+               if (uap->who == 0)
+                       low = td->td_proc->p_nice;
+               else {
+                       p = pfind(uap->who);
+                       if (p == NULL)
+                               break;
+                       if (p_cansee(td, p) == 0)
+                               low = p->p_nice;
+                       PROC_UNLOCK(p);
+               }
+               break;
+
+       case PRIO_PGRP:
+               sx_slock(&proctree_lock);
+               if (uap->who == 0) {
+                       pg = td->td_proc->p_pgrp;
+                       PGRP_LOCK(pg);
+               } else {
+                       pg = pgfind(uap->who);
+                       if (pg == NULL) {
+                               sx_sunlock(&proctree_lock);
+                               break;
+                       }
+               }
+               sx_sunlock(&proctree_lock);
+               LIST_FOREACH(p, &pg->pg_members, p_pglist) {
+                       PROC_LOCK(p);
+                       if (p->p_state == PRS_NORMAL &&
+                           p_cansee(td, p) == 0) {
+                               if (p->p_nice < low)
+                                       low = p->p_nice;
+                       }
+                       PROC_UNLOCK(p);
+               }
+               PGRP_UNLOCK(pg);
+               break;
+
+       case PRIO_USER:
+               if (uap->who == 0)
+                       uap->who = td->td_ucred->cr_uid;
+               sx_slock(&allproc_lock);
+               FOREACH_PROC_IN_SYSTEM(p) {
+                       PROC_LOCK(p);
+                       if (p->p_state == PRS_NORMAL &&
+                           p_cansee(td, p) == 0 &&
+                           p->p_ucred->cr_uid == uap->who) {
+                               if (p->p_nice < low)
+                                       low = p->p_nice;
+                       }
+                       PROC_UNLOCK(p);
+               }
+               sx_sunlock(&allproc_lock);
+               break;
+
+       default:
+               error = EINVAL;
+               break;
+       }
+       if (low == PRIO_MAX + 1 && error == 0)
+               error = ESRCH;
+       td->td_retval[0] = low;
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setpriority_args {
+       int     which;
+       int     who;
+       int     prio;
+};
+#endif
+int
+sys_setpriority(struct thread *td, struct setpriority_args *uap)
+{
+       struct proc *curp, *p;
+       struct pgrp *pg;
+       int found = 0, error = 0;
+
+       curp = td->td_proc;
+       switch (uap->which) {
+       case PRIO_PROCESS:
+               if (uap->who == 0) {
+                       PROC_LOCK(curp);
+                       error = donice(td, curp, uap->prio);
+                       PROC_UNLOCK(curp);
+               } else {
+                       p = pfind(uap->who);
+                       if (p == NULL)
+                               break;
+                       error = p_cansee(td, p);
+                       if (error == 0)
+                               error = donice(td, p, uap->prio);
+                       PROC_UNLOCK(p);
+               }
+               found++;
+               break;
+
+       case PRIO_PGRP:
+               sx_slock(&proctree_lock);
+               if (uap->who == 0) {
+                       pg = curp->p_pgrp;
+                       PGRP_LOCK(pg);
+               } else {
+                       pg = pgfind(uap->who);
+                       if (pg == NULL) {
+                               sx_sunlock(&proctree_lock);
+                               break;
+                       }
+               }
+               sx_sunlock(&proctree_lock);
+               LIST_FOREACH(p, &pg->pg_members, p_pglist) {
+                       PROC_LOCK(p);
+                       if (p->p_state == PRS_NORMAL &&
+                           p_cansee(td, p) == 0) {
+                               error = donice(td, p, uap->prio);
+                               found++;
+                       }
+                       PROC_UNLOCK(p);
+               }
+               PGRP_UNLOCK(pg);
+               break;
+
+       case PRIO_USER:
+               if (uap->who == 0)
+                       uap->who = td->td_ucred->cr_uid;
+               sx_slock(&allproc_lock);
+               FOREACH_PROC_IN_SYSTEM(p) {
+                       PROC_LOCK(p);
+                       if (p->p_state == PRS_NORMAL &&
+                           p->p_ucred->cr_uid == uap->who &&
+                           p_cansee(td, p) == 0) {
+                               error = donice(td, p, uap->prio);
+                               found++;
+                       }
+                       PROC_UNLOCK(p);
+               }
+               sx_sunlock(&allproc_lock);
+               break;
+
+       default:
+               error = EINVAL;
+               break;
+       }
+       if (found == 0 && error == 0)
+               error = ESRCH;
+       return (error);
+}
+
+/*
+ * Set "nice" for a (whole) process.
+ */
+static int
+donice(struct thread *td, struct proc *p, int n)
+{
+       int error;
+
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       if ((error = p_cansched(td, p)))
+               return (error);
+       if (n > PRIO_MAX)
+               n = PRIO_MAX;
+       if (n < PRIO_MIN)
+               n = PRIO_MIN;
+       if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0)
+               return (EACCES);
+       sched_nice(p, n);
+       return (0);
+}
+
+static int unprivileged_idprio;
+SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW,
+    &unprivileged_idprio, 0, "Allow non-root users to set an idle priority");
+
+/*
+ * Set realtime priority for LWP.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct rtprio_thread_args {
+       int             function;
+       lwpid_t         lwpid;
+       struct rtprio   *rtp;
+};
+#endif
+int
+sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap)
+{
+       struct proc *p;
+       struct rtprio rtp;
+       struct thread *td1;
+       int cierror, error;
+
+       /* Perform copyin before acquiring locks if needed. */
+       if (uap->function == RTP_SET)
+               cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
+       else
+               cierror = 0;
+
+       if (uap->lwpid == 0 || uap->lwpid == td->td_tid) {
+               p = td->td_proc;
+               td1 = td;
+               PROC_LOCK(p);
+       } else {
+               /* Only look up thread in current process */
+               td1 = tdfind(uap->lwpid, curproc->p_pid);
+               if (td1 == NULL)
+                       return (ESRCH);
+               p = td1->td_proc;
+       }
+
+       switch (uap->function) {
+       case RTP_LOOKUP:
+               if ((error = p_cansee(td, p)))
+                       break;
+               pri_to_rtp(td1, &rtp);
+               PROC_UNLOCK(p);
+               return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
+       case RTP_SET:
+               if ((error = p_cansched(td, p)) || (error = cierror))
+                       break;
+
+               /* Disallow setting rtprio in most cases if not superuser. */
+
+               /*
+                * Realtime priority has to be restricted for reasons which
+                * should be obvious.  However, for idleprio processes, there is
+                * a potential for system deadlock if an idleprio process gains
+                * a lock on a resource that other processes need (and the
+                * idleprio process can't run due to a CPU-bound normal
+                * process).  Fix me!  XXX
+                *
+                * This problem is not only related to idleprio process.
+                * A user level program can obtain a file lock and hold it
+                * indefinitely.  Additionally, without idleprio processes it is
+                * still conceivable that a program with low priority will never
+                * get to run.  In short, allowing this feature might make it
+                * easier to lock a resource indefinitely, but it is not the
+                * only thing that makes it possible.
+                */
+               if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
+                   (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
+                   unprivileged_idprio == 0)) {
+                       error = priv_check(td, PRIV_SCHED_RTPRIO);
+                       if (error)
+                               break;
+               }
+               error = rtp_to_pri(&rtp, td1);
+               break;
+       default:
+               error = EINVAL;
+               break;
+       }
+       PROC_UNLOCK(p);
+       return (error);
+}
+
+/*
+ * Set realtime priority.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct rtprio_args {
+       int             function;
+       pid_t           pid;
+       struct rtprio   *rtp;
+};
+#endif
+int
+sys_rtprio(struct thread *td, struct rtprio_args *uap)
+{
+       struct proc *p;
+       struct thread *tdp;
+       struct rtprio rtp;
+       int cierror, error;
+
+       /* Perform copyin before acquiring locks if needed. */
+       if (uap->function == RTP_SET)
+               cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
+       else
+               cierror = 0;
+
+       if (uap->pid == 0) {
+               p = td->td_proc;
+               PROC_LOCK(p);
+       } else {
+               p = pfind(uap->pid);
+               if (p == NULL)
+                       return (ESRCH);
+       }
+
+       switch (uap->function) {
+       case RTP_LOOKUP:
+               if ((error = p_cansee(td, p)))
+                       break;
+               /*
+                * Return OUR priority if no pid specified,
+                * or if one is, report the highest priority
+                * in the process.  There isn't much more you can do as
+                * there is only room to return a single priority.
+                * Note: specifying our own pid is not the same
+                * as leaving it zero.
+                */
+               if (uap->pid == 0) {
+                       pri_to_rtp(td, &rtp);
+               } else {
+                       struct rtprio rtp2;
+
+                       rtp.type = RTP_PRIO_IDLE;
+                       rtp.prio = RTP_PRIO_MAX;
+                       FOREACH_THREAD_IN_PROC(p, tdp) {
+                               pri_to_rtp(tdp, &rtp2);
+                               if (rtp2.type <  rtp.type ||
+                                   (rtp2.type == rtp.type &&
+                                   rtp2.prio < rtp.prio)) {
+                                       rtp.type = rtp2.type;
+                                       rtp.prio = rtp2.prio;
+                               }
+                       }
+               }
+               PROC_UNLOCK(p);
+               return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
+       case RTP_SET:
+               if ((error = p_cansched(td, p)) || (error = cierror))
+                       break;
+
+               /*
+                * Disallow setting rtprio in most cases if not superuser.
+                * See the comment in sys_rtprio_thread about idprio
+                * threads holding a lock.
+                */
+               if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
+                   (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
+                   !unprivileged_idprio)) {
+                       error = priv_check(td, PRIV_SCHED_RTPRIO);
+                       if (error)
+                               break;
+               }
+
+               /*
+                * If we are setting our own priority, set just our
+                * thread but if we are doing another process,
+                * do all the threads on that process. If we
+                * specify our own pid we do the latter.
+                */
+               if (uap->pid == 0) {
+                       error = rtp_to_pri(&rtp, td);
+               } else {
+                       FOREACH_THREAD_IN_PROC(p, td) {
+                               if ((error = rtp_to_pri(&rtp, td)) != 0)
+                                       break;
+                       }
+               }
+               break;
+       default:
+               error = EINVAL;
+               break;
+       }
+       PROC_UNLOCK(p);
+       return (error);
+}
+
+int
+rtp_to_pri(struct rtprio *rtp, struct thread *td)
+{
+       u_char  newpri, oldclass, oldpri;
+
+       switch (RTP_PRIO_BASE(rtp->type)) {
+       case RTP_PRIO_REALTIME:
+               if (rtp->prio > RTP_PRIO_MAX)
+                       return (EINVAL);
+               newpri = PRI_MIN_REALTIME + rtp->prio;
+               break;
+       case RTP_PRIO_NORMAL:
+               if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE))
+                       return (EINVAL);
+               newpri = PRI_MIN_TIMESHARE + rtp->prio;
+               break;
+       case RTP_PRIO_IDLE:
+               if (rtp->prio > RTP_PRIO_MAX)
+                       return (EINVAL);
+               newpri = PRI_MIN_IDLE + rtp->prio;
+               break;
+       default:
+               return (EINVAL);
+       }
+
+       thread_lock(td);
+       oldclass = td->td_pri_class;
+       sched_class(td, rtp->type);     /* XXX fix */
+       oldpri = td->td_user_pri;
+       sched_user_prio(td, newpri);
+       if (td->td_user_pri != oldpri && (oldclass != RTP_PRIO_NORMAL ||
+           td->td_pri_class != RTP_PRIO_NORMAL))
+               sched_prio(td, td->td_user_pri);
+       if (TD_ON_UPILOCK(td) && oldpri != newpri) {
+               critical_enter();
+               thread_unlock(td);
+               umtx_pi_adjust(td, oldpri);
+               critical_exit();
+       } else
+               thread_unlock(td);
+       return (0);
+}
+
+void
+pri_to_rtp(struct thread *td, struct rtprio *rtp)
+{
+
+       thread_lock(td);
+       switch (PRI_BASE(td->td_pri_class)) {
+       case PRI_REALTIME:
+               rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME;
+               break;
+       case PRI_TIMESHARE:
+               rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE;
+               break;
+       case PRI_IDLE:
+               rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE;
+               break;
+       default:
+               break;
+       }
+       rtp->type = td->td_pri_class;
+       thread_unlock(td);
+}
+
+#if defined(COMPAT_43)
+#ifndef _SYS_SYSPROTO_H_
+struct osetrlimit_args {
+       u_int   which;
+       struct  orlimit *rlp;
+};
+#endif
+int
+osetrlimit(struct thread *td, struct osetrlimit_args *uap)
+{
+       struct orlimit olim;
+       struct rlimit lim;
+       int error;
+
+       if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
+               return (error);
+       lim.rlim_cur = olim.rlim_cur;
+       lim.rlim_max = olim.rlim_max;
+       error = kern_setrlimit(td, uap->which, &lim);
+       return (error);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct ogetrlimit_args {
+       u_int   which;
+       struct  orlimit *rlp;
+};
+#endif
+int
+ogetrlimit(struct thread *td, struct ogetrlimit_args *uap)
+{
+       struct orlimit olim;
+       struct rlimit rl;
+       int error;
+
+       if (uap->which >= RLIM_NLIMITS)
+               return (EINVAL);
+       lim_rlimit(td, uap->which, &rl);
+
+       /*
+        * XXX would be more correct to convert only RLIM_INFINITY to the
+        * old RLIM_INFINITY and fail with EOVERFLOW for other larger
+        * values.  Most 64->32 and 32->16 conversions, including not
+        * unimportant ones of uids are even more broken than what we
+        * do here (they blindly truncate).  We don't do this correctly
+        * here since we have little experience with EOVERFLOW yet.
+        * Elsewhere, getuid() can't fail...
+        */
+       olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
+       olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
+       error = copyout(&olim, uap->rlp, sizeof(olim));
+       return (error);
+}
+#endif /* COMPAT_43 */
+
+#ifndef _SYS_SYSPROTO_H_
+struct __setrlimit_args {
+       u_int   which;
+       struct  rlimit *rlp;
+};
+#endif
+int
+sys_setrlimit(struct thread *td, struct __setrlimit_args *uap)
+{
+       struct rlimit alim;
+       int error;
+
+       if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
+               return (error);
+       error = kern_setrlimit(td, uap->which, &alim);
+       return (error);
+}
+
+static void
+lim_cb(void *arg)
+{
+       struct rlimit rlim;
+       struct thread *td;
+       struct proc *p;
+
+       p = arg;
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       /*
+        * Check if the process exceeds its cpu resource allocation.  If
+        * it reaches the max, arrange to kill the process in ast().
+        */
+       if (p->p_cpulimit == RLIM_INFINITY)
+               return;
+       PROC_STATLOCK(p);
+       FOREACH_THREAD_IN_PROC(p, td) {
+               ruxagg(p, td);
+       }
+       PROC_STATUNLOCK(p);
+       if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) {
+               lim_rlimit_proc(p, RLIMIT_CPU, &rlim);
+               if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) {
+                       killproc(p, "exceeded maximum CPU limit");
+               } else {
+                       if (p->p_cpulimit < rlim.rlim_max)
+                               p->p_cpulimit += 5;
+                       kern_psignal(p, SIGXCPU);
+               }
+       }
+       if ((p->p_flag & P_WEXIT) == 0)
+               callout_reset_sbt(&p->p_limco, SBT_1S, 0,
+                   lim_cb, p, C_PREL(1));
+}
+
+int
+kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp)
+{
+
+       return (kern_proc_setrlimit(td, td->td_proc, which, limp));
+}
+
+int
+kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which,
+    struct rlimit *limp)
+{
+       struct plimit *newlim, *oldlim;
+       struct rlimit *alimp;
+       struct rlimit oldssiz;
+       int error;
+
+       if (which >= RLIM_NLIMITS)
+               return (EINVAL);
+
+       /*
+        * Preserve historical bugs by treating negative limits as unsigned.
+        */
+       if (limp->rlim_cur < 0)
+               limp->rlim_cur = RLIM_INFINITY;
+       if (limp->rlim_max < 0)
+               limp->rlim_max = RLIM_INFINITY;
+
+       oldssiz.rlim_cur = 0;
+       newlim = lim_alloc();
+       PROC_LOCK(p);
+       oldlim = p->p_limit;
+       alimp = &oldlim->pl_rlimit[which];
+       if (limp->rlim_cur > alimp->rlim_max ||
+           limp->rlim_max > alimp->rlim_max)
+               if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) {
+                       PROC_UNLOCK(p);
+                       lim_free(newlim);
+                       return (error);
+               }
+       if (limp->rlim_cur > limp->rlim_max)
+               limp->rlim_cur = limp->rlim_max;
+       lim_copy(newlim, oldlim);
+       alimp = &newlim->pl_rlimit[which];
+
+       switch (which) {
+
+       case RLIMIT_CPU:
+               if (limp->rlim_cur != RLIM_INFINITY &&
+                   p->p_cpulimit == RLIM_INFINITY)
+                       callout_reset_sbt(&p->p_limco, SBT_1S, 0,
+                           lim_cb, p, C_PREL(1));
+               p->p_cpulimit = limp->rlim_cur;
+               break;
+       case RLIMIT_DATA:
+               if (limp->rlim_cur > maxdsiz)
+                       limp->rlim_cur = maxdsiz;
+               if (limp->rlim_max > maxdsiz)
+                       limp->rlim_max = maxdsiz;
+               break;
+
+       case RLIMIT_STACK:
+               if (limp->rlim_cur > maxssiz)
+                       limp->rlim_cur = maxssiz;
+               if (limp->rlim_max > maxssiz)
+                       limp->rlim_max = maxssiz;
+               oldssiz = *alimp;
+               if (p->p_sysent->sv_fixlimit != NULL)
+                       p->p_sysent->sv_fixlimit(&oldssiz,
+                           RLIMIT_STACK);
+               break;
+
+       case RLIMIT_NOFILE:
+               if (limp->rlim_cur > maxfilesperproc)
+                       limp->rlim_cur = maxfilesperproc;
+               if (limp->rlim_max > maxfilesperproc)
+                       limp->rlim_max = maxfilesperproc;
+               break;
+
+       case RLIMIT_NPROC:
+               if (limp->rlim_cur > maxprocperuid)
+                       limp->rlim_cur = maxprocperuid;
+               if (limp->rlim_max > maxprocperuid)
+                       limp->rlim_max = maxprocperuid;
+               if (limp->rlim_cur < 1)
+                       limp->rlim_cur = 1;
+               if (limp->rlim_max < 1)
+                       limp->rlim_max = 1;
+               break;
+       }
+       if (p->p_sysent->sv_fixlimit != NULL)
+               p->p_sysent->sv_fixlimit(limp, which);
+       *alimp = *limp;
+       p->p_limit = newlim;
+       PROC_UPDATE_COW(p);
+       PROC_UNLOCK(p);
+       lim_free(oldlim);
+
+       if (which == RLIMIT_STACK &&
+           /*
+            * Skip calls from exec_new_vmspace(), done when stack is
+            * not mapped yet.
+            */
+           (td != curthread || (p->p_flag & P_INEXEC) == 0)) {
+               /*
+                * 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 != oldssiz.rlim_cur) {
+                       vm_offset_t addr;
+                       vm_size_t size;
+                       vm_prot_t prot;
+
+                       if (limp->rlim_cur > oldssiz.rlim_cur) {
+                               prot = p->p_sysent->sv_stackprot;
+                               size = limp->rlim_cur - oldssiz.rlim_cur;
+                               addr = p->p_sysent->sv_usrstack -
+                                   limp->rlim_cur;
+                       } else {
+                               prot = VM_PROT_NONE;
+                               size = oldssiz.rlim_cur - limp->rlim_cur;
+                               addr = p->p_sysent->sv_usrstack -
+                                   oldssiz.rlim_cur;
+                       }
+                       addr = trunc_page(addr);
+                       size = round_page(size);
+                       (void)vm_map_protect(&p->p_vmspace->vm_map,
+                           addr, addr + size, prot, FALSE);
+               }
+       }
+
+       return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct __getrlimit_args {
+       u_int   which;
+       struct  rlimit *rlp;
+};
+#endif
+/* ARGSUSED */
+int
+sys_getrlimit(struct thread *td, struct __getrlimit_args *uap)
+{
+       struct rlimit rlim;
+       int error;
+
+       if (uap->which >= RLIM_NLIMITS)
+               return (EINVAL);
+       lim_rlimit(td, uap->which, &rlim);
+       error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
+       return (error);
+}
+
+/*
+ * Transform the running time and tick information for children of proc p
+ * into user and system time usage.
+ */
+void
+calccru(struct proc *p, struct timeval *up, struct timeval *sp)
+{
+
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       calcru1(p, &p->p_crux, up, sp);
+}
+
+/*
+ * Transform the running time and tick information in proc p into user
+ * and system time usage.  If appropriate, include the current time slice
+ * on this CPU.
+ */
+void
+calcru(struct proc *p, struct timeval *up, struct timeval *sp)
+{
+       struct thread *td;
+       uint64_t runtime, u;
+
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       PROC_STATLOCK_ASSERT(p, MA_OWNED);
+       /*
+        * If we are getting stats for the current process, then add in the
+        * stats that this thread has accumulated in its current time slice.
+        * We reset the thread and CPU state as if we had performed a context
+        * switch right here.
+        */
+       td = curthread;
+       if (td->td_proc == p) {
+               u = cpu_ticks();
+               runtime = u - PCPU_GET(switchtime);
+               td->td_runtime += runtime;
+               td->td_incruntime += runtime;
+               PCPU_SET(switchtime, u);
+       }
+       /* Make sure the per-thread stats are current. */
+       FOREACH_THREAD_IN_PROC(p, td) {
+               if (td->td_incruntime == 0)
+                       continue;
+               ruxagg(p, td);
+       }
+       calcru1(p, &p->p_rux, up, sp);
+}
+
+/* Collect resource usage for a single thread. */
+void
+rufetchtd(struct thread *td, struct rusage *ru)
+{
+       struct proc *p;
+       uint64_t runtime, u;
+
+       p = td->td_proc;
+       PROC_STATLOCK_ASSERT(p, MA_OWNED);
+       THREAD_LOCK_ASSERT(td, MA_OWNED);
+       /*
+        * If we are getting stats for the current thread, then add in the
+        * stats that this thread has accumulated in its current time slice.
+        * We reset the thread and CPU state as if we had performed a context
+        * switch right here.
+        */
+       if (td == curthread) {
+               u = cpu_ticks();
+               runtime = u - PCPU_GET(switchtime);
+               td->td_runtime += runtime;
+               td->td_incruntime += runtime;
+               PCPU_SET(switchtime, u);
+       }
+       ruxagg(p, td);
+       *ru = td->td_ru;
+       calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime);
+}
+
+/* XXX: the MI version is too slow to use: */
+#ifndef __HAVE_INLINE_FLSLL
+#define        flsll(x)        (fls((x) >> 32) != 0 ? fls((x) >> 32) + 32 : 
fls(x))
+#endif
+
+static uint64_t
+mul64_by_fraction(uint64_t a, uint64_t b, uint64_t c)
+{
+       uint64_t acc, bh, bl;
+       int i, s, sa, sb;
+
+       /*
+        * Calculate (a * b) / c accurately enough without overflowing.  c
+        * must be nonzero, and its top bit must be 0.  a or b must be
+        * <= c, and the implementation is tuned for b <= c.
+        *
+        * The comments about times are for use in calcru1() with units of
+        * microseconds for 'a' and stathz ticks at 128 Hz for b and c.
+        *
+        * Let n be the number of top zero bits in c.  Each iteration
+        * either returns, or reduces b by right shifting it by at least n.
+        * The number of iterations is at most 1 + 64 / n, and the error is
+        * at most the number of iterations.
+        *
+        * It is very unusual to need even 2 iterations.  Previous
+        * implementations overflowed essentially by returning early in the
+        * first iteration, with n = 38 giving overflow at 105+ hours and
+        * n = 32 giving overlow at at 388+ days despite a more careful
+        * calculation.  388 days is a reasonable uptime, and the calculation
+        * needs to work for the uptime times the number of CPUs since 'a'
+        * is per-process.
+        */
+       if (a >= (uint64_t)1 << 63)
+               return (0);             /* Unsupported arg -- can't happen. */
+       acc = 0;
+       for (i = 0; i < 128; i++) {
+               sa = flsll(a);
+               sb = flsll(b);
+               if (sa + sb <= 64)
+                       /* Up to 105 hours on first iteration. */
+                       return (acc + (a * b) / c);
+               if (a >= c) {
+                       /*
+                        * This reduction is based on a = q * c + r, with the
+                        * remainder r < c.  'a' may be large to start, and
+                        * moving bits from b into 'a' at the end of the loop
+                        * sets the top bit of 'a', so the reduction makes
+                        * significant progress.
+                        */
+                       acc += (a / c) * b;
+                       a %= c;
+                       sa = flsll(a);
+                       if (sa + sb <= 64)
+                               /* Up to 388 days on first iteration. */
+                               return (acc + (a * b) / c);
+               }
+
+               /*
+                * This step writes a * b as a * ((bh << s) + bl) =
+                * a * (bh << s) + a * bl = (a << s) * bh + a * bl.  The 2
+                * additive terms are handled separately.  Splitting in
+                * this way is linear except for rounding errors.
+                *
+                * s = 64 - sa is the maximum such that a << s fits in 64
+                * bits.  Since a < c and c has at least 1 zero top bit,
+                * sa < 64 and s > 0.  Thus this step makes progress by
+                * reducing b (it increases 'a', but taking remainders on
+                * the next iteration completes the reduction).
+                *
+                * Finally, the choice for s is just what is needed to keep
+                * a * bl from overflowing, so we don't need complications
+                * like a recursive call mul64_by_fraction(a, bl, c) to
+                * handle the second additive term.
+                */
+               s = 64 - sa;
+               bh = b >> s;
+               bl = b - (bh << s);
+               acc += (a * bl) / c;
+               a <<= s;
+               b = bh;
+       }
+       return (0);             /* Algorithm failure -- can't happen. */
+}
+
+static void
+calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up,
+    struct timeval *sp)
+{
+       /* {user, system, interrupt, total} {ticks, usec}: */
+       uint64_t ut, uu, st, su, it, tt, tu;
+
+       ut = ruxp->rux_uticks;
+       st = ruxp->rux_sticks;
+       it = ruxp->rux_iticks;
+       tt = ut + st + it;
+       if (tt == 0) {
+               /* Avoid divide by zero */
+               st = 1;
+               tt = 1;
+       }
+       tu = cputick2usec(ruxp->rux_runtime);
+       if ((int64_t)tu < 0) {
+               /* XXX: this should be an assert /phk */
+               printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
+                   (intmax_t)tu, p->p_pid, p->p_comm);
+               tu = ruxp->rux_tu;
+       }
+
+       /* Subdivide tu.  Avoid overflow in the multiplications. */
+       if (__predict_true(tu <= ((uint64_t)1 << 38) && tt <= (1 << 26))) {
+               /* Up to 76 hours when stathz is 128. */
+               uu = (tu * ut) / tt;
+               su = (tu * st) / tt;
+       } else {
+               uu = mul64_by_fraction(tu, ut, tt);
+               su = mul64_by_fraction(tu, st, tt);
+       }
+
+       if (tu >= ruxp->rux_tu) {
+               /*
+                * The normal case, time increased.
+                * Enforce monotonicity of bucketed numbers.
+                */
+               if (uu < ruxp->rux_uu)
+                       uu = ruxp->rux_uu;
+               if (su < ruxp->rux_su)
+                       su = ruxp->rux_su;
+       } else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) {
+               /*
+                * When we calibrate the cputicker, it is not uncommon to
+                * see the presumably fixed frequency increase slightly over
+                * time as a result of thermal stabilization and NTP
+                * discipline (of the reference clock).  We therefore ignore
+                * a bit of backwards slop because we  expect to catch up
+                * shortly.  We use a 3 microsecond limit to catch low
+                * counts and a 1% limit for high counts.
+                */
+               uu = ruxp->rux_uu;
+               su = ruxp->rux_su;
+               tu = ruxp->rux_tu;
+       } else { /* tu < ruxp->rux_tu */
+               /*
+                * What happened here was likely that a laptop, which ran at
+                * a reduced clock frequency at boot, kicked into high gear.
+                * The wisdom of spamming this message in that case is
+                * dubious, but it might also be indicative of something
+                * serious, so lets keep it and hope laptops can be made
+                * more truthful about their CPU speed via ACPI.
+                */
+               printf("calcru: runtime went backwards from %ju usec "
+                   "to %ju usec for pid %d (%s)\n",
+                   (uintmax_t)ruxp->rux_tu, (uintmax_t)tu,
+                   p->p_pid, p->p_comm);
+       }
+
+       ruxp->rux_uu = uu;
+       ruxp->rux_su = su;
+       ruxp->rux_tu = tu;
+
+       up->tv_sec = uu / 1000000;
+       up->tv_usec = uu % 1000000;
+       sp->tv_sec = su / 1000000;
+       sp->tv_usec = su % 1000000;
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getrusage_args {
+       int     who;
+       struct  rusage *rusage;
+};
+#endif
+int
+sys_getrusage(struct thread *td, struct getrusage_args *uap)
+{
+       struct rusage ru;
+       int error;
+
+       error = kern_getrusage(td, uap->who, &ru);
+       if (error == 0)
+               error = copyout(&ru, uap->rusage, sizeof(struct rusage));
+       return (error);
+}
+
+int
+kern_getrusage(struct thread *td, int who, struct rusage *rup)
+{
+       struct proc *p;
+       int error;
+
+       error = 0;
+       p = td->td_proc;
+       PROC_LOCK(p);
+       switch (who) {
+       case RUSAGE_SELF:
+               rufetchcalc(p, rup, &rup->ru_utime,
+                   &rup->ru_stime);
+               break;
+
+       case RUSAGE_CHILDREN:
+               *rup = p->p_stats->p_cru;
+               calccru(p, &rup->ru_utime, &rup->ru_stime);
+               break;
+
+       case RUSAGE_THREAD:
+               PROC_STATLOCK(p);
+               thread_lock(td);
+               rufetchtd(td, rup);
+               thread_unlock(td);
+               PROC_STATUNLOCK(p);
+               break;
+
+       default:
+               error = EINVAL;
+       }
+       PROC_UNLOCK(p);
+       return (error);
+}
+
+void
+rucollect(struct rusage *ru, struct rusage *ru2)
+{
+       long *ip, *ip2;
+       int i;
+
+       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--)
+               *ip++ += *ip2++;
+}
+
+void
+ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
+    struct rusage_ext *rux2)
+{
+
+       rux->rux_runtime += rux2->rux_runtime;
+       rux->rux_uticks += rux2->rux_uticks;
+       rux->rux_sticks += rux2->rux_sticks;
+       rux->rux_iticks += rux2->rux_iticks;
+       rux->rux_uu += rux2->rux_uu;
+       rux->rux_su += rux2->rux_su;
+       rux->rux_tu += rux2->rux_tu;
+       rucollect(ru, ru2);
+}
+
+/*
+ * Aggregate tick counts into the proc's rusage_ext.
+ */
+static void
+ruxagg_locked(struct rusage_ext *rux, struct thread *td)
+{
+
+       THREAD_LOCK_ASSERT(td, MA_OWNED);
+       PROC_STATLOCK_ASSERT(td->td_proc, MA_OWNED);
+       rux->rux_runtime += td->td_incruntime;
+       rux->rux_uticks += td->td_uticks;
+       rux->rux_sticks += td->td_sticks;
+       rux->rux_iticks += td->td_iticks;
+}
+
+void
+ruxagg(struct proc *p, struct thread *td)
+{
+
+       thread_lock(td);
+       ruxagg_locked(&p->p_rux, td);
+       ruxagg_locked(&td->td_rux, td);
+       td->td_incruntime = 0;
+       td->td_uticks = 0;
+       td->td_iticks = 0;
+       td->td_sticks = 0;
+       thread_unlock(td);
+}
+
+/*
+ * Update the rusage_ext structure and fetch a valid aggregate rusage
+ * for proc p if storage for one is supplied.
+ */
+void
+rufetch(struct proc *p, struct rusage *ru)
+{
+       struct thread *td;
+
+       PROC_STATLOCK_ASSERT(p, MA_OWNED);
+
+       *ru = p->p_ru;
+       if (p->p_numthreads > 0)  {
+               FOREACH_THREAD_IN_PROC(p, td) {
+                       ruxagg(p, td);
+                       rucollect(ru, &td->td_ru);
+               }
+       }
+}
+
+/*
+ * Atomically perform a rufetch and a calcru together.
+ * Consumers, can safely assume the calcru is executed only once
+ * rufetch is completed.
+ */
+void
+rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up,
+    struct timeval *sp)
+{
+
+       PROC_STATLOCK(p);
+       rufetch(p, ru);
+       calcru(p, up, sp);
+       PROC_STATUNLOCK(p);
+}
+
+/*
+ * Allocate a new resource limits structure and initialize its
+ * reference count and mutex pointer.
+ */
+struct plimit *
+lim_alloc()
+{
+       struct plimit *limp;
+
+       limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
+       refcount_init(&limp->pl_refcnt, 1);
+       return (limp);
+}
+
+struct plimit *
+lim_hold(struct plimit *limp)
+{
+
+       refcount_acquire(&limp->pl_refcnt);
+       return (limp);
+}
+
+void
+lim_fork(struct proc *p1, struct proc *p2)
+{
+
+       PROC_LOCK_ASSERT(p1, MA_OWNED);
+       PROC_LOCK_ASSERT(p2, MA_OWNED);
+
+       p2->p_limit = lim_hold(p1->p_limit);
+       callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0);
+       if (p1->p_cpulimit != RLIM_INFINITY)
+               callout_reset_sbt(&p2->p_limco, SBT_1S, 0,
+                   lim_cb, p2, C_PREL(1));
+}
+
+void
+lim_free(struct plimit *limp)
+{
+
+       if (refcount_release(&limp->pl_refcnt))
+               free((void *)limp, M_PLIMIT);
+}
+
+/*
+ * Make a copy of the plimit structure.
+ * We share these structures copy-on-write after fork.
+ */
+void
+lim_copy(struct plimit *dst, struct plimit *src)
+{
+
+       KASSERT(dst->pl_refcnt <= 1, ("lim_copy to shared limit"));
+       bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
+}
+
+/*
+ * Return the hard limit for a particular system resource.  The
+ * which parameter specifies the index into the rlimit array.
+ */
+rlim_t
+lim_max(struct thread *td, int which)
+{
+       struct rlimit rl;
+
+       lim_rlimit(td, which, &rl);
+       return (rl.rlim_max);
+}
+
+rlim_t
+lim_max_proc(struct proc *p, int which)
+{
+       struct rlimit rl;
+
+       lim_rlimit_proc(p, which, &rl);
+       return (rl.rlim_max);
+}
+
+/*
+ * Return the current (soft) limit for a particular system resource.
+ * The which parameter which specifies the index into the rlimit array
+ */
+rlim_t
+lim_cur(struct thread *td, int which)
+{
+       struct rlimit rl;
+
+       lim_rlimit(td, which, &rl);
+       return (rl.rlim_cur);
+}
+
+rlim_t
+lim_cur_proc(struct proc *p, int which)
+{
+       struct rlimit rl;
+
+       lim_rlimit_proc(p, which, &rl);
+       return (rl.rlim_cur);
+}
+
+/*
+ * Return a copy of the entire rlimit structure for the system limit
+ * specified by 'which' in the rlimit structure pointed to by 'rlp'.
+ */
+void
+lim_rlimit(struct thread *td, int which, struct rlimit *rlp)
+{
+       struct proc *p = td->td_proc;
+
+       MPASS(td == curthread);
+       KASSERT(which >= 0 && which < RLIM_NLIMITS,
+           ("request for invalid resource limit"));
+       *rlp = td->td_limit->pl_rlimit[which];
+       if (p->p_sysent->sv_fixlimit != NULL)
+               p->p_sysent->sv_fixlimit(rlp, which);
+}
+
+void
+lim_rlimit_proc(struct proc *p, int which, struct rlimit *rlp)
+{
+
+       PROC_LOCK_ASSERT(p, MA_OWNED);
+       KASSERT(which >= 0 && which < RLIM_NLIMITS,
+           ("request for invalid resource limit"));
+       *rlp = p->p_limit->pl_rlimit[which];
+       if (p->p_sysent->sv_fixlimit != NULL)
+               p->p_sysent->sv_fixlimit(rlp, which);
+}
+
+void
+uihashinit()
+{
+
+       uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
+       rw_init(&uihashtbl_lock, "uidinfo hash");
+}
+
+/*
+ * Look up a uidinfo struct for the parameter uid.
+ * uihashtbl_lock must be locked.
+ * Increase refcount on uidinfo struct returned.
+ */
+static struct uidinfo *
+uilookup(uid_t uid)
+{
+       struct uihashhead *uipp;
+       struct uidinfo *uip;
+
+       rw_assert(&uihashtbl_lock, RA_LOCKED);
+       uipp = UIHASH(uid);
+       LIST_FOREACH(uip, uipp, ui_hash)
+               if (uip->ui_uid == uid) {
+                       uihold(uip);
+                       break;
+               }
+
+       return (uip);
+}
+
+/*
+ * Find or allocate a struct uidinfo for a particular uid.
+ * Returns with uidinfo struct referenced.
+ * uifree() should be called on a struct uidinfo when released.
+ */
+struct uidinfo *
+uifind(uid_t uid)
+{
+       struct uidinfo *new_uip, *uip;
+       struct ucred *cred;
+
+       cred = curthread->td_ucred;
+       if (cred->cr_uidinfo->ui_uid == uid) {
+               uip = cred->cr_uidinfo;
+               uihold(uip);
+               return (uip);
+       } else if (cred->cr_ruidinfo->ui_uid == uid) {
+               uip = cred->cr_ruidinfo;
+               uihold(uip);
+               return (uip);
+       }
+
+       rw_rlock(&uihashtbl_lock);
+       uip = uilookup(uid);
+       rw_runlock(&uihashtbl_lock);
+       if (uip != NULL)
+               return (uip);
+
+       new_uip = malloc(sizeof(*new_uip), M_UIDINFO, M_WAITOK | M_ZERO);
+       racct_create(&new_uip->ui_racct);
+       refcount_init(&new_uip->ui_ref, 1);
+       new_uip->ui_uid = uid;
+
+       rw_wlock(&uihashtbl_lock);
+       /*
+        * There's a chance someone created our uidinfo while we
+        * were in malloc and not holding the lock, so we have to
+        * make sure we don't insert a duplicate uidinfo.
+        */
+       if ((uip = uilookup(uid)) == NULL) {
+               LIST_INSERT_HEAD(UIHASH(uid), new_uip, ui_hash);
+               rw_wunlock(&uihashtbl_lock);
+               uip = new_uip;
+       } else {
+               rw_wunlock(&uihashtbl_lock);
+               racct_destroy(&new_uip->ui_racct);
+               free(new_uip, M_UIDINFO);
+       }
+       return (uip);
+}
+
+/*
+ * Place another refcount on a uidinfo struct.
+ */
+void
+uihold(struct uidinfo *uip)
+{
+
+       refcount_acquire(&uip->ui_ref);
+}
+
+/*-
+ * Since uidinfo structs have a long lifetime, we use an
+ * opportunistic refcounting scheme to avoid locking the lookup hash
+ * for each release.
+ *
+ * If the refcount hits 0, we need to free the structure,
+ * which means we need to lock the hash.
+ * Optimal case:
+ *   After locking the struct and lowering the refcount, if we find
+ *   that we don't need to free, simply unlock and return.
+ * Suboptimal case:
+ *   If refcount lowering results in need to free, bump the count
+ *   back up, lose the lock and acquire the locks in the proper
+ *   order to try again.
+ */
+void
+uifree(struct uidinfo *uip)
+{
+       int old;
+
+       /* Prepare for optimal case. */
+       old = uip->ui_ref;
+       if (old > 1 && atomic_cmpset_int(&uip->ui_ref, old, old - 1))
+               return;
+
+       /* Prepare for suboptimal case. */
+       rw_wlock(&uihashtbl_lock);
+       if (refcount_release(&uip->ui_ref) == 0) {
+               rw_wunlock(&uihashtbl_lock);
+               return;
+       }
+
+       racct_destroy(&uip->ui_racct);
+       LIST_REMOVE(uip, ui_hash);
+       rw_wunlock(&uihashtbl_lock);
+
+       if (uip->ui_sbsize != 0)
+               printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
+                   uip->ui_uid, uip->ui_sbsize);
+       if (uip->ui_proccnt != 0)
+               printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
+                   uip->ui_uid, uip->ui_proccnt);
+       if (uip->ui_vmsize != 0)
+               printf("freeing uidinfo: uid = %d, swapuse = %lld\n",
+                   uip->ui_uid, (unsigned long long)uip->ui_vmsize);
+       free(uip, M_UIDINFO);
+}
+
+#ifdef RACCT
+void
+ui_racct_foreach(void (*callback)(struct racct *racct,
+    void *arg2, void *arg3), void (*pre)(void), void (*post)(void),
+    void *arg2, void *arg3)
+{
+       struct uidinfo *uip;
+       struct uihashhead *uih;
+
+       rw_rlock(&uihashtbl_lock);
+       if (pre != NULL)
+               (pre)();
+       for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) {
+               LIST_FOREACH(uip, uih, ui_hash) {
+                       (callback)(uip->ui_racct, arg2, arg3);
+               }
+       }
+       if (post != NULL)
+               (post)();
+       rw_runlock(&uihashtbl_lock);
+}
+#endif
+
+static inline int
+chglimit(struct uidinfo *uip, long *limit, int diff, rlim_t max, const char 
*name)
+{
+       long new;
+
+       /* Don't allow them to exceed max, but allow subtraction. */
+       new = atomic_fetchadd_long(limit, (long)diff) + diff;
+       if (diff > 0 && max != 0) {
+               if (new < 0 || new > max) {
+                       atomic_subtract_long(limit, (long)diff);
+                       return (0);
+               }
+       } else if (new < 0)
+               printf("negative %s for uid = %d\n", name, uip->ui_uid);
+       return (1);
+}
+
+/*
+ * Change the count associated with number of processes
+ * a given user is using.  When 'max' is 0, don't enforce a limit
+ */
+int
+chgproccnt(struct uidinfo *uip, int diff, rlim_t max)
+{
+
+       return (chglimit(uip, &uip->ui_proccnt, diff, max, "proccnt"));
+}
+
+/*
+ * Change the total socket buffer size a user has used.
+ */
+int
+chgsbsize(struct uidinfo *uip, u_int *hiwat, u_int to, rlim_t max)
+{
+       int diff, rv;
+
+       diff = to - *hiwat;
+       if (diff > 0 && max == 0) {
+               rv = 0;
+       } else {
+               rv = chglimit(uip, &uip->ui_sbsize, diff, max, "sbsize");
+               if (rv != 0)
+                       *hiwat = to;
+       }
+       return (rv);
+}
+
+/*
+ * Change the count associated with number of pseudo-terminals
+ * a given user is using.  When 'max' is 0, don't enforce a limit
+ */
+int
+chgptscnt(struct uidinfo *uip, int diff, rlim_t max)
+{
+
+       return (chglimit(uip, &uip->ui_ptscnt, diff, max, "ptscnt"));
+}
+
+int
+chgkqcnt(struct uidinfo *uip, int diff, rlim_t max)
+{
+
+       return (chglimit(uip, &uip->ui_kqcnt, diff, max, "kqcnt"));
+}
+
+int
+chgumtxcnt(struct uidinfo *uip, int diff, rlim_t max)
+{
+
+       return (chglimit(uip, &uip->ui_umtxcnt, diff, max, "umtxcnt"));
+}
-- 
2.24.1

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