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sys/kern/kern_exit.c
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1 /* $NetBSD: kern_exit.c,v 1.139 2004/03/14 01:08:47 cl Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1989, 1991, 1993 42 * The Regents of the University of California. All rights reserved. 43 * (c) UNIX System Laboratories, Inc. 44 * All or some portions of this file are derived from material licensed 45 * to the University of California by American Telephone and Telegraph 46 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 47 * the permission of UNIX System Laboratories, Inc. 48 * 49 * Redistribution and use in source and binary forms, with or without 50 * modification, are permitted provided that the following conditions 51 * are met: 52 * 1. Redistributions of source code must retain the above copyright 53 * notice, this list of conditions and the following disclaimer. 54 * 2. Redistributions in binary form must reproduce the above copyright 55 * notice, this list of conditions and the following disclaimer in the 56 * documentation and/or other materials provided with the distribution. 57 * 3. Neither the name of the University nor the names of its contributors 58 * may be used to endorse or promote products derived from this software 59 * without specific prior written permission. 60 * 61 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 62 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 63 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 64 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 65 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 66 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 67 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 68 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 69 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 70 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 71 * SUCH DAMAGE. 72 * 73 * @(#)kern_exit.c 8.10 (Berkeley) 2/23/95 74 */ 75 76 #include <sys/cdefs.h> 77 __KERNEL_RCSID(0, "$NetBSD: kern_exit.c,v 1.139 2004/03/14 01:08:47 cl Exp $"); 78 79 #include "opt_ktrace.h" 80 #include "opt_perfctrs.h" 81 #include "opt_systrace.h" 82 #include "opt_sysv.h" 83 84 #include <sys/param.h> 85 #include <sys/systm.h> 86 #include <sys/ioctl.h> 87 #include <sys/proc.h> 88 #include <sys/tty.h> 89 #include <sys/time.h> 90 #include <sys/resource.h> 91 #include <sys/kernel.h> 92 #include <sys/ktrace.h> 93 #include <sys/proc.h> 94 #include <sys/buf.h> 95 #include <sys/wait.h> 96 #include <sys/file.h> 97 #include <sys/vnode.h> 98 #include <sys/syslog.h> 99 #include <sys/malloc.h> 100 #include <sys/pool.h> 101 #include <sys/resourcevar.h> 102 #if defined(PERFCTRS) 103 #include <sys/pmc.h> 104 #endif 105 #include <sys/ptrace.h> 106 #include <sys/acct.h> 107 #include <sys/filedesc.h> 108 #include <sys/ras.h> 109 #include <sys/signalvar.h> 110 #include <sys/sched.h> 111 #include <sys/sa.h> 112 #include <sys/savar.h> 113 #include <sys/mount.h> 114 #include <sys/syscallargs.h> 115 #include <sys/systrace.h> 116 117 #include <machine/cpu.h> 118 119 #include <uvm/uvm_extern.h> 120 121 #define DEBUG_EXIT 122 123 #ifdef DEBUG_EXIT 124 int debug_exit = 0; 125 #define DPRINTF(x) if (debug_exit) printf x 126 #else 127 #define DPRINTF(x) 128 #endif 129 130 static void lwp_exit_hook(struct lwp *, void *); 131 static void exit_psignal(struct proc *, struct proc *); 132 133 /* 134 * Fill in the appropriate signal information, and signal the parent. 135 */ 136 static void 137 exit_psignal(struct proc *p, struct proc *pp) 138 { 139 ksiginfo_t ksi; 140 141 (void)memset(&ksi, 0, sizeof(ksi)); 142 if ((ksi.ksi_signo = P_EXITSIG(p)) == SIGCHLD) { 143 if (WIFSIGNALED(p->p_xstat)) { 144 if (WCOREDUMP(p->p_xstat)) 145 ksi.ksi_code = CLD_DUMPED; 146 else 147 ksi.ksi_code = CLD_KILLED; 148 } else { 149 ksi.ksi_code = CLD_EXITED; 150 } 151 } 152 /* 153 * we fill those in, even for non-SIGCHLD. 154 */ 155 ksi.ksi_pid = p->p_pid; 156 ksi.ksi_uid = p->p_ucred->cr_uid; 157 ksi.ksi_status = p->p_xstat; 158 /* XXX: is this still valid? */ 159 ksi.ksi_utime = p->p_ru->ru_utime.tv_sec; 160 ksi.ksi_stime = p->p_ru->ru_stime.tv_sec; 161 kpsignal(pp, &ksi, NULL); 162 } 163 164 /* 165 * exit -- 166 * Death of process. 167 */ 168 int 169 sys_exit(struct lwp *l, void *v, register_t *retval) 170 { 171 struct sys_exit_args /* { 172 syscallarg(int) rval; 173 } */ *uap = v; 174 175 /* Don't call exit1() multiple times in the same process.*/ 176 if (l->l_proc->p_flag & P_WEXIT) 177 lwp_exit(l); 178 179 exit1(l, W_EXITCODE(SCARG(uap, rval), 0)); 180 /* NOTREACHED */ 181 return (0); 182 } 183 184 /* 185 * Exit: deallocate address space and other resources, change proc state 186 * to zombie, and unlink proc from allproc and parent's lists. Save exit 187 * status and rusage for wait(). Check for child processes and orphan them. 188 */ 189 void 190 exit1(struct lwp *l, int rv) 191 { 192 struct proc *p, *q, *nq; 193 int s, sa; 194 195 p = l->l_proc; 196 197 if (__predict_false(p == initproc)) 198 panic("init died (signal %d, exit %d)", 199 WTERMSIG(rv), WEXITSTATUS(rv)); 200 201 p->p_flag |= P_WEXIT; 202 if (p->p_flag & P_STOPEXIT) { 203 int s; 204 205 sigminusset(&contsigmask, &p->p_sigctx.ps_siglist); 206 SCHED_LOCK(s); 207 p->p_stat = SSTOP; 208 l->l_stat = LSSTOP; 209 p->p_nrlwps--; 210 mi_switch(l, NULL); 211 SCHED_ASSERT_UNLOCKED(); 212 splx(s); 213 } 214 215 DPRINTF(("exit1: %d.%d exiting.\n", p->p_pid, l->l_lid)); 216 /* 217 * Disable scheduler activation upcalls. 218 * We're trying to get out of here. 219 */ 220 sa = 0; 221 if (p->p_sa != NULL) { 222 l->l_flag &= ~L_SA; 223 #if 0 224 p->p_flag &= ~P_SA; 225 #endif 226 sa = 1; 227 } 228 229 #ifdef PGINPROF 230 vmsizmon(); 231 #endif 232 if (p->p_flag & P_PROFIL) 233 stopprofclock(p); 234 p->p_ru = pool_get(&rusage_pool, PR_WAITOK); 235 /* 236 * If parent is waiting for us to exit or exec, P_PPWAIT is set; we 237 * wake up the parent early to avoid deadlock. 238 */ 239 if (p->p_flag & P_PPWAIT) { 240 p->p_flag &= ~P_PPWAIT; 241 wakeup(p->p_pptr); 242 } 243 sigfillset(&p->p_sigctx.ps_sigignore); 244 sigemptyset(&p->p_sigctx.ps_siglist); 245 p->p_sigctx.ps_sigcheck = 0; 246 timers_free(p, TIMERS_ALL); 247 248 if (sa || (p->p_nlwps > 1)) { 249 exit_lwps(l); 250 251 /* 252 * Collect thread u-areas. 253 */ 254 uvm_uarea_drain(FALSE); 255 } 256 257 #if defined(__HAVE_RAS) 258 ras_purgeall(p); 259 #endif 260 261 /* 262 * Close open files and release open-file table. 263 * This may block! 264 */ 265 fdfree(p); 266 cwdfree(p); 267 268 doexithooks(p); 269 270 if (SESS_LEADER(p)) { 271 struct session *sp = p->p_session; 272 struct tty *tp; 273 274 if (sp->s_ttyvp) { 275 int s; 276 /* 277 * Controlling process. 278 * Signal foreground pgrp, 279 * drain controlling terminal 280 * and revoke access to controlling terminal. 281 */ 282 tp = sp->s_ttyp; 283 s = spltty(); 284 TTY_LOCK(tp); 285 if (tp->t_session == sp) { 286 if (tp->t_pgrp) 287 pgsignal(tp->t_pgrp, SIGHUP, 1); 288 /* we can't guarantee the revoke will do this */ 289 tp->t_pgrp = NULL; 290 tp->t_session = NULL; 291 TTY_UNLOCK(tp); 292 splx(s); 293 SESSRELE(sp); 294 (void) ttywait(tp); 295 /* 296 * The tty could have been revoked 297 * if we blocked. 298 */ 299 if (sp->s_ttyvp) 300 VOP_REVOKE(sp->s_ttyvp, REVOKEALL); 301 } else { 302 TTY_UNLOCK(tp); 303 splx(s); 304 } 305 if (sp->s_ttyvp) 306 vrele(sp->s_ttyvp); 307 sp->s_ttyvp = NULL; 308 /* 309 * s_ttyp is not zero'd; we use this to indicate 310 * that the session once had a controlling terminal. 311 * (for logging and informational purposes) 312 */ 313 } 314 sp->s_leader = NULL; 315 } 316 fixjobc(p, p->p_pgrp, 0); 317 (void)acct_process(p); 318 #ifdef KTRACE 319 /* 320 * release trace file 321 */ 322 ktrderef(p); 323 #endif 324 #ifdef SYSTRACE 325 systrace_sys_exit(p); 326 #endif 327 /* 328 * If emulation has process exit hook, call it now. 329 */ 330 if (p->p_emul->e_proc_exit) 331 (*p->p_emul->e_proc_exit)(p); 332 333 /* 334 * Reset p_opptr pointer of all former children which got 335 * traced by another process and were reparented. We reset 336 * it to NULL here; the trace detach code then reparents 337 * the child to initproc. We only check allproc list, since 338 * eventual former children on zombproc list won't reference 339 * p_opptr anymore. 340 */ 341 s = proclist_lock_write(); 342 if (p->p_flag & P_CHTRACED) { 343 LIST_FOREACH(q, &allproc, p_list) { 344 if (q->p_opptr == p) 345 q->p_opptr = NULL; 346 } 347 } 348 349 /* 350 * Give orphaned children to init(8). 351 */ 352 q = LIST_FIRST(&p->p_children); 353 if (q) /* only need this if any child is SZOMB */ 354 wakeup(initproc); 355 for (; q != NULL; q = nq) { 356 nq = LIST_NEXT(q, p_sibling); 357 358 /* 359 * Traced processes are killed since their existence 360 * means someone is screwing up. Since we reset the 361 * trace flags, the logic in sys_wait4() would not be 362 * triggered to reparent the process to its 363 * original parent, so we must do this here. 364 */ 365 if (q->p_flag & P_TRACED) { 366 if (q->p_opptr != q->p_pptr) { 367 struct proc *t = q->p_opptr; 368 proc_reparent(q, t ? t : initproc); 369 q->p_opptr = NULL; 370 } else 371 proc_reparent(q, initproc); 372 q->p_flag &= ~(P_TRACED|P_WAITED|P_FSTRACE); 373 psignal(q, SIGKILL); 374 } else { 375 proc_reparent(q, initproc); 376 } 377 } 378 proclist_unlock_write(s); 379 380 /* 381 * Free the VM resources we're still holding on to. 382 * We must do this from a valid thread because doing 383 * so may block. This frees vmspace, which we don't 384 * need anymore. The only remaining lwp is the one 385 * we run at this moment, nothing runs in userland 386 * anymore. 387 */ 388 uvm_proc_exit(p); 389 390 /* 391 * Give machine-dependent code a chance to free any 392 * MD LWP resources while we can still block. This must be done 393 * before uvm_lwp_exit(), in case these resources are in the 394 * PCB. 395 * THIS IS LAST BLOCKING OPERATION. 396 */ 397 #ifndef __NO_CPU_LWP_FREE 398 cpu_lwp_free(l, 1); 399 #endif 400 401 pmap_deactivate(l); 402 403 /* 404 * NOTE: WE ARE NO LONGER ALLOWED TO SLEEP! 405 */ 406 407 /* 408 * Save exit status and final rusage info, adding in child rusage 409 * info and self times. 410 * In order to pick up the time for the current execution, we must 411 * do this before unlinking the lwp from l_list. 412 */ 413 p->p_xstat = rv; 414 *p->p_ru = p->p_stats->p_ru; 415 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 416 ruadd(p->p_ru, &p->p_stats->p_cru); 417 418 /* 419 * Move proc from allproc to zombproc, it's now ready 420 * to be collected by parent. Remaining lwp resources 421 * will be freed in lwp_exit2() once we'd switch to idle 422 * context. 423 * Changing the state to SZOMB stops it being found by pfind(). 424 */ 425 s = proclist_lock_write(); 426 LIST_REMOVE(p, p_list); 427 LIST_INSERT_HEAD(&zombproc, p, p_list); 428 p->p_stat = SZOMB; 429 430 LIST_REMOVE(l, l_list); 431 LIST_REMOVE(l, l_sibling); 432 l->l_flag |= L_DETACHED|L_PROCEXIT; /* detached from proc too */ 433 l->l_stat = LSDEAD; 434 435 p->p_nrlwps--; 436 p->p_nlwps--; 437 438 /* Put in front of parent's sibling list for parent to collect it */ 439 q = p->p_pptr; 440 q->p_nstopchild++; 441 if (LIST_FIRST(&q->p_children) != p) { 442 /* Put child where it can be found quickly */ 443 LIST_REMOVE(p, p_sibling); 444 LIST_INSERT_HEAD(&q->p_children, p, p_sibling); 445 } 446 447 proclist_unlock_write(s); 448 449 /* 450 * Notify interested parties of our demise. 451 */ 452 KNOTE(&p->p_klist, NOTE_EXIT); 453 454 #if PERFCTRS 455 /* 456 * Save final PMC information in parent process & clean up. 457 */ 458 if (PMC_ENABLED(p)) { 459 pmc_save_context(p); 460 pmc_accumulate(p->p_pptr, p); 461 pmc_process_exit(p); 462 } 463 #endif 464 465 /* 466 * Notify parent that we're gone. If parent has the P_NOCLDWAIT 467 * flag set, notify init instead (and hope it will handle 468 * this situation). 469 */ 470 if (p->p_pptr->p_flag & P_NOCLDWAIT) { 471 struct proc *pp = p->p_pptr; 472 proc_reparent(p, initproc); 473 474 /* 475 * If this was the last child of our parent, notify 476 * parent, so in case he was wait(2)ing, he will 477 * continue. 478 */ 479 if (LIST_FIRST(&pp->p_children) == NULL) 480 wakeup(pp); 481 } 482 483 /* Wake up the parent so it can get exit status. */ 484 if ((p->p_flag & P_FSTRACE) == 0 && p->p_exitsig != 0) 485 exit_psignal(p, p->p_pptr); 486 wakeup(p->p_pptr); 487 488 /* 489 * Release the process's signal state. 490 */ 491 sigactsfree(p); 492 493 /* 494 * Clear curlwp after we've done all operations 495 * that could block, and before tearing down the rest 496 * of the process state that might be used from clock, etc. 497 * Also, can't clear curlwp while we're still runnable, 498 * as we're not on a run queue (we are current, just not 499 * a proper proc any longer!). 500 * 501 * Other substructures are freed from wait(). 502 */ 503 curlwp = NULL; 504 limfree(p->p_limit); 505 pstatsfree(p->p_stats); 506 p->p_limit = NULL; 507 508 /* This process no longer needs to hold the kernel lock. */ 509 KERNEL_PROC_UNLOCK(l); 510 511 #ifdef DEBUG 512 /* Nothing should use the process link anymore */ 513 l->l_proc = NULL; 514 #endif 515 516 /* 517 * Finally, call machine-dependent code to switch to a new 518 * context (possibly the idle context). Once we are no longer 519 * using the dead lwp's stack, lwp_exit2() will be called 520 * to arrange for the resources to be released. 521 * 522 * Note that cpu_exit() will end with a call equivalent to 523 * cpu_switch(), finishing our execution (pun intended). 524 */ 525 526 uvmexp.swtch++; 527 cpu_exit(l); 528 } 529 530 void 531 exit_lwps(struct lwp *l) 532 { 533 struct proc *p; 534 struct lwp *l2; 535 struct sadata_vp *vp; 536 int s, error; 537 lwpid_t waited; 538 539 p = l->l_proc; 540 541 /* XXX SMP 542 * This would be the right place to IPI any LWPs running on 543 * other processors so that they can notice the userret exit hook. 544 */ 545 p->p_userret = lwp_exit_hook; 546 p->p_userret_arg = NULL; 547 548 if (p->p_sa) { 549 SLIST_FOREACH(vp, &p->p_sa->sa_vps, savp_next) { 550 /* 551 * Make SA-cached LWPs normal process runnable 552 * LWPs so that they'll also self-destruct. 553 */ 554 DPRINTF(("exit_lwps: Making cached LWPs of %d on VP %d runnable: ", 555 p->p_pid, vp->savp_id)); 556 SCHED_LOCK(s); 557 while ((l2 = sa_getcachelwp(vp)) != 0) { 558 l2->l_priority = l2->l_usrpri; 559 setrunnable(l2); 560 DPRINTF(("%d ", l2->l_lid)); 561 } 562 SCHED_UNLOCK(s); 563 DPRINTF(("\n")); 564 565 /* 566 * Clear wokenq, the LWPs on the queue will 567 * run below. 568 */ 569 vp->savp_wokenq_head = NULL; 570 } 571 } 572 573 /* 574 * Interrupt LWPs in interruptable sleep, unsuspend suspended 575 * LWPs, make detached LWPs undetached (so we can wait for 576 * them) and then wait for everyone else to finish. 577 */ 578 LIST_FOREACH(l2, &p->p_lwps, l_sibling) { 579 l2->l_flag &= ~(L_DETACHED|L_SA); 580 581 if ((l2->l_stat == LSSLEEP && (l2->l_flag & L_SINTR)) || 582 l2->l_stat == LSSUSPENDED || l2->l_stat == LSSTOP) { 583 SCHED_LOCK(s); 584 setrunnable(l2); 585 SCHED_UNLOCK(s); 586 DPRINTF(("exit_lwps: Made %d.%d runnable\n", 587 p->p_pid, l2->l_lid)); 588 } 589 } 590 591 592 while (p->p_nlwps > 1) { 593 DPRINTF(("exit_lwps: waiting for %d LWPs (%d runnable, %d zombies)\n", 594 p->p_nlwps, p->p_nrlwps, p->p_nzlwps)); 595 error = lwp_wait1(l, 0, &waited, LWPWAIT_EXITCONTROL); 596 if (error) 597 panic("exit_lwps: lwp_wait1 failed with error %d\n", 598 error); 599 DPRINTF(("exit_lwps: Got LWP %d from lwp_wait1()\n", waited)); 600 } 601 602 p->p_userret = NULL; 603 } 604 605 /* Wrapper function for use in p_userret */ 606 static void 607 lwp_exit_hook(struct lwp *l, void *arg) 608 { 609 KERNEL_PROC_LOCK(l); 610 lwp_exit(l); 611 } 612 613 int 614 sys_wait4(struct lwp *l, void *v, register_t *retval) 615 { 616 struct sys_wait4_args /* { 617 syscallarg(int) pid; 618 syscallarg(int *) status; 619 syscallarg(int) options; 620 syscallarg(struct rusage *) rusage; 621 } */ *uap = v; 622 struct proc *child, *parent; 623 int status, error; 624 625 parent = l->l_proc; 626 627 if (SCARG(uap, pid) == 0) 628 SCARG(uap, pid) = -parent->p_pgid; 629 if (SCARG(uap, options) & ~(WUNTRACED|WNOHANG|WALTSIG|WALLSIG)) 630 return (EINVAL); 631 632 error = find_stopped_child(parent, SCARG(uap,pid), SCARG(uap,options), 633 &child); 634 if (error != 0) 635 return error; 636 if (child == NULL) { 637 *retval = 0; 638 return 0; 639 } 640 641 /* 642 * Collect child u-areas. 643 */ 644 uvm_uarea_drain(FALSE); 645 646 retval[0] = child->p_pid; 647 648 if (child->p_stat == SZOMB) { 649 if (SCARG(uap, status)) { 650 status = child->p_xstat; /* convert to int */ 651 error = copyout(&status, SCARG(uap, status), 652 sizeof(status)); 653 if (error) 654 return (error); 655 } 656 if (SCARG(uap, rusage)) { 657 error = copyout(child->p_ru, SCARG(uap, rusage), 658 sizeof(struct rusage)); 659 if (error) 660 return (error); 661 } 662 663 proc_free(child); 664 return 0; 665 } 666 667 /* child state must be SSTOP */ 668 if (SCARG(uap, status)) { 669 status = W_STOPCODE(child->p_xstat); 670 return copyout(&status, SCARG(uap, status), sizeof(status)); 671 } 672 return 0; 673 } 674 675 /* 676 * Scan list of child processes for a child process that has stopped or 677 * exited. Used by sys_wait4 and 'compat' equivalents. 678 */ 679 int 680 find_stopped_child(struct proc *parent, pid_t pid, int options, 681 struct proc **child_p) 682 { 683 struct proc *child; 684 int error; 685 686 for (;;) { 687 proclist_lock_read(); 688 error = ECHILD; 689 LIST_FOREACH(child, &parent->p_children, p_sibling) { 690 if (pid >= 0) { 691 if (child->p_pid != pid) { 692 child = p_find(pid, PFIND_ZOMBIE | 693 PFIND_LOCKED); 694 if (child == NULL 695 || child->p_pptr != parent) { 696 child = NULL; 697 break; 698 } 699 } 700 } else 701 if (pid != WAIT_ANY && child->p_pgid != -pid) 702 /* child not in correct pgrp */ 703 continue; 704 /* 705 * Wait for processes with p_exitsig != SIGCHLD 706 * processes only if WALTSIG is set; wait for 707 * processes with p_exitsig == SIGCHLD only 708 * if WALTSIG is clear. 709 */ 710 if (((options & WALLSIG) == 0) && 711 (options & WALTSIG ? child->p_exitsig == SIGCHLD 712 : P_EXITSIG(child) != SIGCHLD)){ 713 if (child->p_pid == pid) { 714 child = NULL; 715 break; 716 } 717 continue; 718 } 719 720 error = 0; 721 if (child->p_stat == SZOMB && !(options & WNOZOMBIE)) 722 break; 723 724 if (child->p_stat == SSTOP && 725 (child->p_flag & P_WAITED) == 0 && 726 (child->p_flag & P_TRACED || options & WUNTRACED)) { 727 if ((options & WNOWAIT) == 0) { 728 child->p_flag |= P_WAITED; 729 parent->p_nstopchild--; 730 } 731 break; 732 } 733 if (parent->p_nstopchild == 0 || child->p_pid == pid) { 734 child = NULL; 735 break; 736 } 737 } 738 proclist_unlock_read(); 739 if (child != NULL || error != 0 || options & WNOHANG) { 740 *child_p = child; 741 return error; 742 } 743 error = tsleep(parent, PWAIT | PCATCH, "wait", 0); 744 if (error != 0) 745 return error; 746 } 747 } 748 749 /* 750 * Free a process after parent has taken all the state info. 751 */ 752 void 753 proc_free(struct proc *p) 754 { 755 struct proc *parent = p->p_pptr; 756 int s; 757 758 KASSERT(p->p_nlwps == 0); 759 KASSERT(p->p_nzlwps == 0); 760 KASSERT(p->p_nrlwps == 0); 761 KASSERT(LIST_EMPTY(&p->p_lwps)); 762 763 /* 764 * If we got the child via ptrace(2) or procfs, and 765 * the parent is different (meaning the process was 766 * attached, rather than run as a child), then we need 767 * to give it back to the old parent, and send the 768 * parent the exit signal. The rest of the cleanup 769 * will be done when the old parent waits on the child. 770 */ 771 if ((p->p_flag & P_TRACED) && p->p_opptr != parent){ 772 parent = p->p_opptr; 773 if (parent == NULL) 774 parent = initproc; 775 proc_reparent(p, parent); 776 p->p_opptr = NULL; 777 p->p_flag &= ~(P_TRACED|P_WAITED|P_FSTRACE); 778 if (p->p_exitsig != 0) 779 exit_psignal(p, parent); 780 wakeup(parent); 781 return; 782 } 783 784 scheduler_wait_hook(parent, p); 785 p->p_xstat = 0; 786 787 ruadd(&parent->p_stats->p_cru, p->p_ru); 788 789 /* 790 * At this point we are going to start freeing the final resources. 791 * If anyone tries to access the proc structure after here they 792 * will get a shock - bits are missing. 793 * Attempt to make it hard! 794 */ 795 796 p->p_stat = SIDL; /* not even a zombie any more */ 797 798 pool_put(&rusage_pool, p->p_ru); 799 800 /* 801 * Finally finished with old proc entry. 802 * Unlink it from its process group and free it. 803 */ 804 leavepgrp(p); 805 806 s = proclist_lock_write(); 807 LIST_REMOVE(p, p_list); /* off zombproc */ 808 p->p_pptr->p_nstopchild--; 809 LIST_REMOVE(p, p_sibling); 810 proclist_unlock_write(s); 811 812 /* 813 * Decrement the count of procs running with this uid. 814 */ 815 (void)chgproccnt(p->p_cred->p_ruid, -1); 816 817 /* 818 * Free up credentials. 819 */ 820 if (--p->p_cred->p_refcnt == 0) { 821 crfree(p->p_cred->pc_ucred); 822 pool_put(&pcred_pool, p->p_cred); 823 } 824 825 /* 826 * Release reference to text vnode 827 */ 828 if (p->p_textvp) 829 vrele(p->p_textvp); 830 831 /* Release any SA state. */ 832 if (p->p_sa) 833 sa_release(p); 834 835 /* Free proc structure and let pid be reallocated */ 836 proc_free_mem(p); 837 } 838 839 /* 840 * make process 'parent' the new parent of process 'child'. 841 * 842 * Must be called with proclist_lock_write() held. 843 */ 844 void 845 proc_reparent(struct proc *child, struct proc *parent) 846 { 847 848 if (child->p_pptr == parent) 849 return; 850 851 if (child->p_stat == SZOMB 852 || (child->p_stat == SSTOP && !(child->p_flag & P_WAITED))) { 853 child->p_pptr->p_nstopchild--; 854 parent->p_nstopchild++; 855 } 856 if (parent == initproc) 857 child->p_exitsig = SIGCHLD; 858 859 LIST_REMOVE(child, p_sibling); 860 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 861 child->p_pptr = parent; 862 }
Cache object: 90621e77415cceb19b55425633bab6b0
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