bsd/kern/kern_fork.c

   1 /*
   2  * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  26 /*
  27  * Copyright (c) 1982, 1986, 1989, 1991, 1993
  28  *      The Regents of the University of California.  All rights reserved.
  29  * (c) UNIX System Laboratories, Inc.
  30  * All or some portions of this file are derived from material licensed
  31  * to the University of California by American Telephone and Telegraph
  32  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  33  * the permission of UNIX System Laboratories, Inc.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by the University of
  46  *      California, Berkeley and its contributors.
  47  * 4. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  *      @(#)kern_fork.c 8.8 (Berkeley) 2/14/95
  64  */
  65
  66 #include <kern/assert.h>
  67 #include <sys/param.h>
  68 #include <sys/systm.h>
  69 #include <sys/filedesc.h>
  70 #include <sys/kernel.h>
  71 #include <sys/malloc.h>
  72 #include <sys/proc.h>
  73 #include <sys/user.h>
  74 #include <sys/resourcevar.h>
  75 #include <sys/vnode.h>
  76 #include <sys/file.h>
  77 #include <sys/acct.h>
  78 #include <sys/kern_audit.h>
  79 #if KTRACE
  80 #include <sys/ktrace.h>
  81 #endif
  82
  83 #include <mach/mach_types.h>
  84 #include <kern/mach_param.h>
  85
  86 #include <machine/spl.h>
  87
  88 thread_act_t cloneproc(struct proc *, int);
  89 struct proc * forkproc(struct proc *, int);
  90 thread_act_t procdup();
  91
  92 #define DOFORK  0x1     /* fork() system call */
  93 #define DOVFORK 0x2     /* vfork() system call */
  94 static int fork1(struct proc *, long, register_t *);
  95
  96 /*
  97  * fork system call.
  98  */
  99 int
 100 fork(p, uap, retval)
 101         struct proc *p;
 102         void *uap;
 103         register_t *retval;
 104 {
 105         return (fork1(p, (long)DOFORK, retval));
 106 }
 107
 108 /*
 109  * vfork system call
 110  */
 111 int
 112 vfork(p, uap, retval)
 113         struct proc *p;
 114         void *uap;
 115         register_t *retval;
 116 {
 117         register struct proc * newproc;
 118         register uid_t uid;
 119         thread_act_t cur_act = (thread_act_t)current_act();
 120         int count;
 121         task_t t;
 122         uthread_t ut;
 123
 124         /*
 125          * Although process entries are dynamically created, we still keep
 126          * a global limit on the maximum number we will create.  Don't allow
 127          * a nonprivileged user to use the last process; don't let root
 128          * exceed the limit. The variable nprocs is the current number of
 129          * processes, maxproc is the limit.
 130          */
 131         uid = p->p_cred->p_ruid;
 132         if ((nprocs >= maxproc - 1 && uid != 0) || nprocs >= maxproc) {
 133                 tablefull("proc");
 134                 retval[1] = 0;
 135                 return (EAGAIN);
 136         }
 137
 138         /*
 139          * Increment the count of procs running with this uid. Don't allow
 140          * a nonprivileged user to exceed their current limit.
 141          */
 142         count = chgproccnt(uid, 1);
 143         if (uid != 0 && count > p->p_rlimit[RLIMIT_NPROC].rlim_cur) {
 144                 (void)chgproccnt(uid, -1);
 145                 return (EAGAIN);
 146         }
 147
 148         ut = (struct uthread *)get_bsdthread_info(cur_act);
 149         if (ut->uu_flag & P_VFORK) {
 150                 printf("vfork called recursively by %s\n", p->p_comm);
 151                 (void)chgproccnt(uid, -1);
 152                 return (EINVAL);
 153         }
 154         p->p_flag  |= P_VFORK;
 155         p->p_vforkcnt++;
 156
 157         /* The newly created process comes with signal lock held */
 158         newproc = (struct proc *)forkproc(p,1);
 159
 160         LIST_INSERT_AFTER(p, newproc, p_pglist);
 161         newproc->p_pptr = p;
 162         newproc->task = p->task;
 163         LIST_INSERT_HEAD(&p->p_children, newproc, p_sibling);
 164         LIST_INIT(&newproc->p_children);
 165         LIST_INSERT_HEAD(&allproc, newproc, p_list);
 166         LIST_INSERT_HEAD(PIDHASH(newproc->p_pid), newproc, p_hash);
 167         TAILQ_INIT(& newproc->p_evlist);
 168         newproc->p_stat = SRUN;
 169         newproc->p_flag  |= P_INVFORK;
 170         newproc->p_vforkact = cur_act;
 171
 172         ut->uu_flag |= P_VFORK;
 173         ut->uu_proc = newproc;
 174         ut->uu_userstate = (void *)act_thread_csave();
 175         ut->uu_vforkmask = ut->uu_sigmask;
 176
 177         thread_set_child(cur_act, newproc->p_pid);
 178
 179         newproc->p_stats->p_start = time;
 180         newproc->p_acflag = AFORK;
 181
 182         /*
 183          * Preserve synchronization semantics of vfork.  If waiting for
 184          * child to exec or exit, set P_PPWAIT on child, and sleep on our
 185          * proc (in case of exit).
 186          */
 187         newproc->p_flag |= P_PPWAIT;
 188
 189         /* drop the signal lock on the child */
 190         signal_unlock(newproc);
 191
 192         retval[0] = newproc->p_pid;
 193         retval[1] = 1;                  /* mark child */
 194
 195         return (0);
 196 }
 197
 198 /*
 199  * Return to parent vfork ehread()
 200  */
 201 void
 202 vfork_return(th_act, p, p2, retval)
 203         thread_act_t th_act;
 204         struct proc * p;
 205         struct proc *p2;
 206         register_t *retval;
 207 {
 208         long flags;
 209         register uid_t uid;
 210         thread_act_t cur_act = (thread_act_t)current_act();
 211         int s, count;
 212         task_t t;
 213         uthread_t ut;
 214
 215         ut = (struct uthread *)get_bsdthread_info(cur_act);
 216
 217         act_thread_catt(ut->uu_userstate);
 218
 219         /* Make sure only one at this time */
 220         p->p_vforkcnt--;
 221         if (p->p_vforkcnt <0)
 222                 panic("vfork cnt is -ve");
 223         if (p->p_vforkcnt <=0)
 224                 p->p_flag  &= ~P_VFORK;
 225         ut->uu_userstate = 0;
 226         ut->uu_flag &= ~P_VFORK;
 227         ut->uu_proc = 0;
 228         ut->uu_sigmask = ut->uu_vforkmask;
 229         p2->p_flag  &= ~P_INVFORK;
 230         p2->p_vforkact = (void *)0;
 231
 232         thread_set_parent(cur_act, p2->p_pid);
 233
 234         if (retval) {
 235                 retval[0] = p2->p_pid;
 236                 retval[1] = 0;                  /* mark parent */
 237         }
 238
 239         return;
 240 }
 241
 242 thread_act_t
 243 procdup(
 244         struct proc             *child,
 245         struct proc             *parent)
 246 {
 247         thread_act_t            thread;
 248         task_t                  task;
 249         kern_return_t   result;
 250         pmap_t                  pmap;
 251         extern task_t kernel_task;
 252
 253         if (parent->task == kernel_task)
 254                 result = task_create_internal(TASK_NULL, FALSE, &task);
 255         else
 256                 result = task_create_internal(parent->task, TRUE, &task);
 257         if (result != KERN_SUCCESS)
 258             printf("fork/procdup: task_create failed. Code: 0x%x\n", result);
 259         child->task = task;
 260         /* task->proc = child; */
 261         set_bsdtask_info(task, child);
 262         if (child->p_nice != 0)
 263                 resetpriority(child);
 264
 265         result = thread_create(task, &thread);
 266         if (result != KERN_SUCCESS)
 267             printf("fork/procdup: thread_create failed. Code: 0x%x\n", result);
 268
 269         return(thread);
 270 }
 271
 272
 273 static int
 274 fork1(p1, flags, retval)
 275         struct proc *p1;
 276         long flags;
 277         register_t *retval;
 278 {
 279         register struct proc *p2;
 280         register uid_t uid;
 281         thread_act_t newth;
 282         int s, count;
 283         task_t t;
 284
 285         /*
 286          * Although process entries are dynamically created, we still keep
 287          * a global limit on the maximum number we will create.  Don't allow
 288          * a nonprivileged user to use the last process; don't let root
 289          * exceed the limit. The variable nprocs is the current number of
 290          * processes, maxproc is the limit.
 291          */
 292         uid = p1->p_cred->p_ruid;
 293         if ((nprocs >= maxproc - 1 && uid != 0) || nprocs >= maxproc) {
 294                 tablefull("proc");
 295                 retval[1] = 0;
 296                 return (EAGAIN);
 297         }
 298
 299         /*
 300          * Increment the count of procs running with this uid. Don't allow
 301          * a nonprivileged user to exceed their current limit.
 302          */
 303         count = chgproccnt(uid, 1);
 304         if (uid != 0 && count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur) {
 305                 (void)chgproccnt(uid, -1);
 306                 return (EAGAIN);
 307         }
 308
 309         /* The newly created process comes with signal lock held */
 310         newth = cloneproc(p1, 1);
 311         thread_dup(newth);
 312         /* p2 = newth->task->proc; */
 313         p2 = (struct proc *)(get_bsdtask_info(get_threadtask(newth)));
 314
 315         thread_set_child(newth, p2->p_pid);
 316
 317         s = splhigh();
 318         p2->p_stats->p_start = time;
 319         splx(s);
 320         p2->p_acflag = AFORK;
 321
 322         /*
 323          * Preserve synchronization semantics of vfork.  If waiting for
 324          * child to exec or exit, set P_PPWAIT on child, and sleep on our
 325          * proc (in case of exit).
 326          */
 327         if (flags == DOVFORK)
 328                 p2->p_flag |= P_PPWAIT;
 329         /* drop the signal lock on the child */
 330         signal_unlock(p2);
 331
 332         (void) thread_resume(newth);
 333
 334         /* drop the extra references we got during the creation */
 335         if (t = (task_t)get_threadtask(newth)) {
 336                 task_deallocate(t);
 337         }
 338         act_deallocate(newth);
 339
 340         KNOTE(&p1->p_klist, NOTE_FORK | p2->p_pid);
 341
 342         while (p2->p_flag & P_PPWAIT)
 343                 tsleep(p1, PWAIT, "ppwait", 0);
 344
 345         retval[0] = p2->p_pid;
 346         retval[1] = 0;                  /* mark parent */
 347
 348         return (0);
 349 }
 350
 351 /*
 352  * cloneproc()
 353  *
 354  * Create a new process from a specified process.
 355  * On return newly created child process has signal
 356  * lock held to block delivery of signal to it if called with
 357  * lock set. fork() code needs to explicity remove this lock
 358  * before signals can be delivered
 359  */
 360 thread_act_t
 361 cloneproc(p1, lock)
 362         register struct proc *p1;
 363         register int lock;
 364 {
 365         register struct proc *p2;
 366         thread_act_t th;
 367
 368         p2 = (struct proc *)forkproc(p1,lock);
 369
 370
 371         th = procdup(p2, p1);   /* child, parent */
 372
 373         LIST_INSERT_AFTER(p1, p2, p_pglist);
 374         p2->p_pptr = p1;
 375         LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling);
 376         LIST_INIT(&p2->p_children);
 377         LIST_INSERT_HEAD(&allproc, p2, p_list);
 378         LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
 379         TAILQ_INIT(&p2->p_evlist);
 380         /*
 381          * Make child runnable, set start time.
 382          */
 383         p2->p_stat = SRUN;
 384
 385         return(th);
 386 }
 387
 388 struct proc *
 389 forkproc(p1, lock)
 390         register struct proc *p1;
 391         register int lock;
 392 {
 393         register struct proc *p2, *newproc;
 394         static int nextpid = 0, pidchecked = 0;
 395         thread_t th;
 396
 397         /* Allocate new proc. */
 398         MALLOC_ZONE(newproc, struct proc *,
 399                         sizeof *newproc, M_PROC, M_WAITOK);
 400         MALLOC_ZONE(newproc->p_cred, struct pcred *,
 401                         sizeof *newproc->p_cred, M_SUBPROC, M_WAITOK);
 402         MALLOC_ZONE(newproc->p_stats, struct pstats *,
 403                         sizeof *newproc->p_stats, M_SUBPROC, M_WAITOK);
 404         MALLOC_ZONE(newproc->p_sigacts, struct sigacts *,
 405                         sizeof *newproc->p_sigacts, M_SUBPROC, M_WAITOK);
 406
 407         /*
 408          * Find an unused process ID.  We remember a range of unused IDs
 409          * ready to use (from nextpid+1 through pidchecked-1).
 410          */
 411         nextpid++;
 412 retry:
 413         /*
 414          * If the process ID prototype has wrapped around,
 415          * restart somewhat above 0, as the low-numbered procs
 416          * tend to include daemons that don't exit.
 417          */
 418         if (nextpid >= PID_MAX) {
 419                 nextpid = 100;
 420                 pidchecked = 0;
 421         }
 422         if (nextpid >= pidchecked) {
 423                 int doingzomb = 0;
 424
 425                 pidchecked = PID_MAX;
 426                 /*
 427                  * Scan the active and zombie procs to check whether this pid
 428                  * is in use.  Remember the lowest pid that's greater
 429                  * than nextpid, so we can avoid checking for a while.
 430                  */
 431                 p2 = allproc.lh_first;
 432 again:
 433                 for (; p2 != 0; p2 = p2->p_list.le_next) {
 434                         while (p2->p_pid == nextpid ||
 435                             p2->p_pgrp->pg_id == nextpid ||
 436                                 p2->p_session->s_sid == nextpid) {
 437                                 nextpid++;
 438                                 if (nextpid >= pidchecked)
 439                                         goto retry;
 440                         }
 441                         if (p2->p_pid > nextpid && pidchecked > p2->p_pid)
 442                                 pidchecked = p2->p_pid;
 443                         if (p2->p_pgrp && p2->p_pgrp->pg_id > nextpid &&
 444                             pidchecked > p2->p_pgrp->pg_id)
 445                                 pidchecked = p2->p_pgrp->pg_id;
 446                         if (p2->p_session->s_sid > nextpid &&
 447                                 pidchecked > p2->p_session->s_sid)
 448                                 pidchecked = p2->p_session->s_sid;
 449                 }
 450                 if (!doingzomb) {
 451                         doingzomb = 1;
 452                         p2 = zombproc.lh_first;
 453                         goto again;
 454                 }
 455         }
 456
 457         nprocs++;
 458         p2 = newproc;
 459         p2->p_stat = SIDL;
 460         p2->p_pid = nextpid;
 461
 462         /*
 463          * Make a proc table entry for the new process.
 464          * Start by zeroing the section of proc that is zero-initialized,
 465          * then copy the section that is copied directly from the parent.
 466          */
 467         bzero(&p2->p_startzero,
 468             (unsigned) ((caddr_t)&p2->p_endzero - (caddr_t)&p2->p_startzero));
 469         bcopy(&p1->p_startcopy, &p2->p_startcopy,
 470             (unsigned) ((caddr_t)&p2->p_endcopy - (caddr_t)&p2->p_startcopy));
 471         p2->vm_shm = (void *)NULL; /* Make sure it is zero */
 472
 473         /*
 474          * Copy the audit info.
 475          */
 476         audit_proc_fork(p1, p2);
 477
 478         /*
 479          * Duplicate sub-structures as needed.
 480          * Increase reference counts on shared objects.
 481          * The p_stats and p_sigacts substructs are set in vm_fork.
 482          */
 483         p2->p_flag = P_INMEM;
 484         p2->p_flag |= (p1->p_flag & P_CLASSIC); // copy from parent
 485         p2->p_flag |= (p1->p_flag & P_AFFINITY); // copy from parent
 486         if (p1->p_flag & P_PROFIL)
 487                 startprofclock(p2);
 488         bcopy(p1->p_cred, p2->p_cred, sizeof(*p2->p_cred));
 489         p2->p_cred->p_refcnt = 1;
 490         crhold(p1->p_ucred);
 491         lockinit(&p2->p_cred->pc_lock, PLOCK, "proc cred", 0, 0);
 492         klist_init(&p2->p_klist);
 493
 494         /* bump references to the text vnode */
 495         p2->p_textvp = p1->p_textvp;
 496         if (p2->p_textvp)
 497                 VREF(p2->p_textvp);
 498
 499         p2->p_fd = fdcopy(p1);
 500         if (p1->vm_shm) {
 501                 shmfork(p1,p2);
 502         }
 503         /*
 504          * If p_limit is still copy-on-write, bump refcnt,
 505          * otherwise get a copy that won't be modified.
 506          * (If PL_SHAREMOD is clear, the structure is shared
 507          * copy-on-write.)
 508          */
 509         if (p1->p_limit->p_lflags & PL_SHAREMOD)
 510                 p2->p_limit = limcopy(p1->p_limit);
 511         else {
 512                 p2->p_limit = p1->p_limit;
 513                 p2->p_limit->p_refcnt++;
 514         }
 515
 516         bzero(&p2->p_stats->pstat_startzero,
 517             (unsigned) ((caddr_t)&p2->p_stats->pstat_endzero -
 518             (caddr_t)&p2->p_stats->pstat_startzero));
 519         bcopy(&p1->p_stats->pstat_startcopy, &p2->p_stats->pstat_startcopy,
 520             ((caddr_t)&p2->p_stats->pstat_endcopy -
 521              (caddr_t)&p2->p_stats->pstat_startcopy));
 522
 523         if (p1->p_sigacts != NULL)
 524                 (void)memcpy(p2->p_sigacts,
 525                                 p1->p_sigacts, sizeof *p2->p_sigacts);
 526         else
 527                 (void)memset(p2->p_sigacts, 0, sizeof *p2->p_sigacts);
 528
 529         if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT)
 530                 p2->p_flag |= P_CONTROLT;
 531
 532         p2->p_argslen = p1->p_argslen;
 533         p2->p_argc = p1->p_argc;
 534         p2->p_xstat = 0;
 535         p2->p_ru = NULL;
 536
 537         p2->p_debugger = 0;     /* don't inherit */
 538         lockinit(&p2->signal_lock, PVM, "signal", 0, 0);
 539         /* block all signals to reach the process */
 540         if (lock)
 541                 signal_lock(p2);
 542         p2->sigwait = FALSE;
 543         p2->sigwait_thread = NULL;
 544         p2->exit_thread = NULL;
 545         p2->user_stack = p1->user_stack;
 546         p2->p_vforkcnt = 0;
 547         p2->p_vforkact = 0;
 548         TAILQ_INIT(&p2->p_uthlist);
 549         TAILQ_INIT(&p2->aio_activeq);
 550         TAILQ_INIT(&p2->aio_doneq);
 551         p2->aio_active_count = 0;
 552         p2->aio_done_count = 0;
 553
 554 #if KTRACE
 555         /*
 556          * Copy traceflag and tracefile if enabled.
 557          * If not inherited, these were zeroed above.
 558          */
 559         if (p1->p_traceflag&KTRFAC_INHERIT) {
 560                 p2->p_traceflag = p1->p_traceflag;
 561                 if ((p2->p_tracep = p1->p_tracep) != NULL)
 562                         VREF(p2->p_tracep);
 563         }
 564 #endif
 565         return(p2);
 566
 567 }
 568
 569 #include <kern/zalloc.h>
 570
 571 struct zone     *uthread_zone;
 572 int uthread_zone_inited = 0;
 573
 574 void
 575 uthread_zone_init()
 576 {
 577         if (!uthread_zone_inited) {
 578                 uthread_zone = zinit(sizeof(struct uthread),
 579                                                         THREAD_MAX * sizeof(struct uthread),
 580                                                         THREAD_CHUNK * sizeof(struct uthread),
 581                                                         "uthreads");
 582                 uthread_zone_inited = 1;
 583         }
 584 }
 585
 586 void *
 587 uthread_alloc(task_t task, thread_act_t thr_act )
 588 {
 589         struct proc *p;
 590         struct uthread *uth, *uth_parent;
 591         void *ut;
 592         extern task_t kernel_task;
 593         boolean_t funnel_state;
 594
 595         if (!uthread_zone_inited)
 596                 uthread_zone_init();
 597
 598         ut = (void *)zalloc(uthread_zone);
 599         bzero(ut, sizeof(struct uthread));
 600
 601         if (task != kernel_task) {
 602                 uth = (struct uthread *)ut;
 603                 p = (struct proc *) get_bsdtask_info(task);
 604
 605                 funnel_state = thread_funnel_set(kernel_flock, TRUE);
 606                 uth_parent = (struct uthread *)get_bsdthread_info(current_act());
 607                 if (uth_parent) {
 608                         if (uth_parent->uu_flag & USAS_OLDMASK)
 609                                 uth->uu_sigmask = uth_parent->uu_oldmask;
 610                         else
 611                                 uth->uu_sigmask = uth_parent->uu_sigmask;
 612                 }
 613                 uth->uu_act = thr_act;
 614                 //signal_lock(p);
 615                 if (p)
 616                         TAILQ_INSERT_TAIL(&p->p_uthlist, uth, uu_list);
 617                 //signal_unlock(p);
 618                 (void)thread_funnel_set(kernel_flock, funnel_state);
 619         }
 620
 621         return (ut);
 622 }
 623
 624
 625 void
 626 uthread_free(task_t task, void *uthread, void * bsd_info)
 627 {
 628         struct _select *sel;
 629         struct uthread *uth = (struct uthread *)uthread;
 630         struct proc * p = (struct proc *)bsd_info;
 631         extern task_t kernel_task;
 632         int size;
 633         boolean_t funnel_state;
 634         struct nlminfo *nlmp;
 635
 636         /*
 637          * Per-thread audit state should never last beyond system
 638          * call return.  Since we don't audit the thread creation/
 639          * removal, the thread state pointer should never be
 640          * non-NULL when we get here.
 641          */
 642         assert(uth->uu_ar == NULL);
 643
 644         sel = &uth->uu_state.ss_select;
 645         /* cleanup the select bit space */
 646         if (sel->nbytes) {
 647                 FREE(sel->ibits, M_TEMP);
 648                 FREE(sel->obits, M_TEMP);
 649         }
 650
 651         if (sel->allocsize && uth->uu_wqsub){
 652                 kfree(uth->uu_wqsub, sel->allocsize);
 653                 sel->count = sel->nfcount = 0;
 654                 sel->allocsize = 0;
 655                 uth->uu_wqsub = 0;
 656                 sel->wql = 0;
 657         }
 658
 659         if ((nlmp = uth->uu_nlminfo)) {
 660                 uth->uu_nlminfo = 0;
 661                 FREE(nlmp, M_LOCKF);
 662         }
 663
 664         if ((task != kernel_task) && p) {
 665                 funnel_state = thread_funnel_set(kernel_flock, TRUE);
 666                 //signal_lock(p);
 667                 TAILQ_REMOVE(&p->p_uthlist, uth, uu_list);
 668                 //signal_unlock(p);
 669                 (void)thread_funnel_set(kernel_flock, funnel_state);
 670         }
 671         /* and free the uthread itself */
 672         zfree(uthread_zone, (vm_offset_t)uthread);
 673 }