1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 39 * $Id: kern_exit.c,v 1.57 1997/10/11 18:31:22 phk Exp $ 40 */ 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/malloc.h> 48 #include <sys/proc.h> 49 #include <sys/tty.h> 50 #include <sys/wait.h> 51 #include <sys/vnode.h> 52 #include <sys/resourcevar.h> 53 #include <sys/signalvar.h> 54 #include <sys/ptrace.h> 55 #include <sys/acct.h> /* for acct_process() function prototype */ 56 #include <sys/filedesc.h> 57 #include <sys/shm.h> 58 #include <sys/sem.h> 59 #include <sys/aio.h> 60 61 #ifdef COMPAT_43 62 #include <machine/reg.h> 63 #include <machine/psl.h> 64 #endif 65 #include <machine/limits.h> /* for UCHAR_MAX = typeof(p_priority)_MAX */ 66 67 #include <vm/vm.h> 68 #include <vm/vm_param.h> 69 #include <sys/lock.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_map.h> 72 73 static MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 74 75 static int wait1 __P((struct proc *, struct wait_args *, int [], int)); 76 77 /* 78 * callout list for things to do at exit time 79 */ 80 typedef struct exit_list_element { 81 struct exit_list_element *next; 82 exitlist_fn function; 83 } *ele_p; 84 85 static ele_p exit_list; 86 87 /* 88 * exit -- 89 * Death of process. 90 */ 91 void 92 exit(p, uap, retval) 93 struct proc *p; 94 struct rexit_args /* { 95 int rval; 96 } */ *uap; 97 int *retval; 98 { 99 100 exit1(p, W_EXITCODE(uap->rval, 0)); 101 /* NOTREACHED */ 102 } 103 104 /* 105 * Exit: deallocate address space and other resources, change proc state 106 * to zombie, and unlink proc from allproc and parent's lists. Save exit 107 * status and rusage for wait(). Check for child processes and orphan them. 108 */ 109 void 110 exit1(p, rv) 111 register struct proc *p; 112 int rv; 113 { 114 register struct proc *q, *nq; 115 register struct vmspace *vm; 116 ele_p ep = exit_list; 117 118 if (p->p_pid == 1) { 119 printf("init died (signal %d, exit %d)\n", 120 WTERMSIG(rv), WEXITSTATUS(rv)); 121 panic("Going nowhere without my init!"); 122 } 123 124 aio_proc_rundown(p); 125 126 /* are we a task leader? */ 127 if(p == p->p_leader) { 128 struct kill_args killArgs; 129 killArgs.signum = SIGKILL; 130 q = p->p_peers; 131 while(q) { 132 killArgs.pid = q->p_pid; 133 /* 134 * The interface for kill is better 135 * than the internal signal 136 */ 137 kill(p, &killArgs, &rv); 138 nq = q; 139 q = q->p_peers; 140 /* 141 * orphan the threads so we don't mess up 142 * when they call exit 143 */ 144 nq->p_peers = 0; 145 nq->p_leader = nq; 146 } 147 148 /* otherwise are we a peer? */ 149 } else if(p->p_peers) { 150 q = p->p_leader; 151 while(q->p_peers != p) 152 q = q->p_peers; 153 q->p_peers = p->p_peers; 154 } 155 156 #ifdef PGINPROF 157 vmsizmon(); 158 #endif 159 /* 160 * Check if any LKMs need anything done at process exit. 161 * e.g. SYSV IPC stuff 162 * XXX what if one of these generates an error? 163 */ 164 while (ep) { 165 (*ep->function)(p); 166 ep = ep->next; 167 } 168 169 if (p->p_flag & P_PROFIL) 170 stopprofclock(p); 171 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 172 M_ZOMBIE, M_WAITOK); 173 /* 174 * If parent is waiting for us to exit or exec, 175 * P_PPWAIT is set; we will wakeup the parent below. 176 */ 177 p->p_flag &= ~(P_TRACED | P_PPWAIT); 178 p->p_flag |= P_WEXIT; 179 p->p_sigignore = ~0; 180 p->p_siglist = 0; 181 if (timerisset(&p->p_realtimer.it_value)) 182 untimeout(realitexpire, (caddr_t)p, p->p_ithandle); 183 184 /* 185 * Close open files and release open-file table. 186 * This may block! 187 */ 188 fdfree(p); 189 190 /* 191 * XXX Shutdown SYSV semaphores 192 */ 193 semexit(p); 194 195 /* The next two chunks should probably be moved to vmspace_exit. */ 196 vm = p->p_vmspace; 197 /* 198 * Release user portion of address space. 199 * This releases references to vnodes, 200 * which could cause I/O if the file has been unlinked. 201 * Need to do this early enough that we can still sleep. 202 * Can't free the entire vmspace as the kernel stack 203 * may be mapped within that space also. 204 */ 205 if (vm->vm_refcnt == 1) { 206 if (vm->vm_shm) 207 shmexit(p); 208 pmap_remove_pages(&vm->vm_pmap, VM_MIN_ADDRESS, 209 VM_MAXUSER_ADDRESS); 210 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 211 VM_MAXUSER_ADDRESS); 212 } 213 214 if (SESS_LEADER(p)) { 215 register struct session *sp = p->p_session; 216 217 if (sp->s_ttyvp) { 218 /* 219 * Controlling process. 220 * Signal foreground pgrp, 221 * drain controlling terminal 222 * and revoke access to controlling terminal. 223 */ 224 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 225 if (sp->s_ttyp->t_pgrp) 226 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 227 (void) ttywait(sp->s_ttyp); 228 /* 229 * The tty could have been revoked 230 * if we blocked. 231 */ 232 if (sp->s_ttyvp) 233 VOP_REVOKE(sp->s_ttyvp, REVOKEALL); 234 } 235 if (sp->s_ttyvp) 236 vrele(sp->s_ttyvp); 237 sp->s_ttyvp = NULL; 238 /* 239 * s_ttyp is not zero'd; we use this to indicate 240 * that the session once had a controlling terminal. 241 * (for logging and informational purposes) 242 */ 243 } 244 sp->s_leader = NULL; 245 } 246 fixjobc(p, p->p_pgrp, 0); 247 if (p->p_limit->p_refcnt > 1 && 248 (p->p_limit->p_lflags & PL_SHAREMOD) == 0) { 249 p->p_limit->p_refcnt--; 250 p->p_limit = limcopy(p->p_limit); 251 } 252 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 253 (void)acct_process(p); 254 #ifdef KTRACE 255 /* 256 * release trace file 257 */ 258 p->p_traceflag = 0; /* don't trace the vrele() */ 259 if (p->p_tracep) 260 vrele(p->p_tracep); 261 #endif 262 /* 263 * Remove proc from allproc queue and pidhash chain. 264 * Place onto zombproc. Unlink from parent's child list. 265 */ 266 LIST_REMOVE(p, p_list); 267 LIST_INSERT_HEAD(&zombproc, p, p_list); 268 p->p_stat = SZOMB; 269 270 LIST_REMOVE(p, p_hash); 271 272 q = p->p_children.lh_first; 273 if (q) /* only need this if any child is S_ZOMB */ 274 wakeup((caddr_t) initproc); 275 for (; q != 0; q = nq) { 276 nq = q->p_sibling.le_next; 277 LIST_REMOVE(q, p_sibling); 278 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling); 279 q->p_pptr = initproc; 280 /* 281 * Traced processes are killed 282 * since their existence means someone is screwing up. 283 */ 284 if (q->p_flag & P_TRACED) { 285 q->p_flag &= ~P_TRACED; 286 psignal(q, SIGKILL); 287 } 288 } 289 290 /* 291 * Save exit status and final rusage info, adding in child rusage 292 * info and self times. 293 */ 294 p->p_xstat = rv; 295 *p->p_ru = p->p_stats->p_ru; 296 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 297 ruadd(p->p_ru, &p->p_stats->p_cru); 298 299 /* 300 * Notify parent that we're gone. If parent has the P_NOCLDWAIT 301 * flag set, notify process 1 instead (and hope it will handle 302 * this situation). 303 */ 304 if (p->p_pptr->p_flag & P_NOCLDWAIT) { 305 struct proc *pp = p->p_pptr; 306 proc_reparent(p, initproc); 307 /* 308 * If this was the last child of our parent, notify 309 * parent, so in case he was wait(2)ing, he will 310 * continue. 311 */ 312 if (LIST_EMPTY(&pp->p_children)) 313 wakeup((caddr_t)pp); 314 } 315 316 psignal(p->p_pptr, SIGCHLD); 317 wakeup((caddr_t)p->p_pptr); 318 #if defined(tahoe) 319 /* move this to cpu_exit */ 320 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 321 #endif 322 /* 323 * Clear curproc after we've done all operations 324 * that could block, and before tearing down the rest 325 * of the process state that might be used from clock, etc. 326 * Also, can't clear curproc while we're still runnable, 327 * as we're not on a run queue (we are current, just not 328 * a proper proc any longer!). 329 * 330 * Other substructures are freed from wait(). 331 */ 332 curproc = NULL; 333 if (--p->p_limit->p_refcnt == 0) { 334 FREE(p->p_limit, M_SUBPROC); 335 p->p_limit = NULL; 336 } 337 338 /* 339 * Finally, call machine-dependent code to release the remaining 340 * resources including address space, the kernel stack and pcb. 341 * The address space is released by "vmspace_free(p->p_vmspace)"; 342 * This is machine-dependent, as we may have to change stacks 343 * or ensure that the current one isn't reallocated before we 344 * finish. cpu_exit will end with a call to cpu_switch(), finishing 345 * our execution (pun intended). 346 */ 347 cpu_exit(p); 348 } 349 350 #ifdef COMPAT_43 351 #if defined(hp300) || defined(luna68k) 352 #include <machine/frame.h> 353 #define GETPS(rp) ((struct frame *)(rp))->f_sr 354 #else 355 #define GETPS(rp) (rp)[PS] 356 #endif 357 358 int 359 owait(p, uap, retval) 360 struct proc *p; 361 register struct owait_args /* { 362 int dummy; 363 } */ *uap; 364 int *retval; 365 { 366 struct wait_args w; 367 368 #ifdef PSL_ALLCC 369 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 370 w.options = 0; 371 w.rusage = NULL; 372 } else { 373 w.options = p->p_md.md_regs[R0]; 374 w.rusage = (struct rusage *)p->p_md.md_regs[R1]; 375 } 376 #else 377 w.options = 0; 378 w.rusage = NULL; 379 #endif 380 w.pid = WAIT_ANY; 381 w.status = NULL; 382 return (wait1(p, &w, retval, 1)); 383 } 384 #endif /* COMPAT_43 */ 385 386 int 387 wait4(p, uap, retval) 388 struct proc *p; 389 struct wait_args *uap; 390 int *retval; 391 { 392 393 return (wait1(p, uap, retval, 0)); 394 } 395 396 static int 397 wait1(q, uap, retval, compat) 398 register struct proc *q; 399 register struct wait_args /* { 400 int pid; 401 int *status; 402 int options; 403 struct rusage *rusage; 404 } */ *uap; 405 int retval[]; 406 int compat; 407 { 408 register int nfound; 409 register struct proc *p, *t; 410 int status, error; 411 412 if (uap->pid == 0) 413 uap->pid = -q->p_pgid; 414 #ifdef notyet 415 if (uap->options &~ (WUNTRACED|WNOHANG)) 416 return (EINVAL); 417 #endif 418 loop: 419 nfound = 0; 420 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 421 if (uap->pid != WAIT_ANY && 422 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 423 continue; 424 nfound++; 425 if (p->p_stat == SZOMB) { 426 /* charge childs scheduling cpu usage to parent */ 427 if (curproc->p_pid != 1) { 428 curproc->p_estcpu = min(curproc->p_estcpu + 429 p->p_estcpu, UCHAR_MAX); 430 } 431 432 retval[0] = p->p_pid; 433 #ifdef COMPAT_43 434 if (compat) 435 retval[1] = p->p_xstat; 436 else 437 #endif 438 if (uap->status) { 439 status = p->p_xstat; /* convert to int */ 440 if ((error = copyout((caddr_t)&status, 441 (caddr_t)uap->status, sizeof(status)))) 442 return (error); 443 } 444 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 445 (caddr_t)uap->rusage, sizeof (struct rusage)))) 446 return (error); 447 /* 448 * If we got the child via a ptrace 'attach', 449 * we need to give it back to the old parent. 450 */ 451 if (p->p_oppid && (t = pfind(p->p_oppid))) { 452 p->p_oppid = 0; 453 proc_reparent(p, t); 454 psignal(t, SIGCHLD); 455 wakeup((caddr_t)t); 456 return (0); 457 } 458 p->p_xstat = 0; 459 ruadd(&q->p_stats->p_cru, p->p_ru); 460 FREE(p->p_ru, M_ZOMBIE); 461 p->p_ru = NULL; 462 463 /* 464 * Decrement the count of procs running with this uid. 465 */ 466 (void)chgproccnt(p->p_cred->p_ruid, -1); 467 468 /* 469 * Release reference to text vnode 470 */ 471 if (p->p_textvp) 472 vrele(p->p_textvp); 473 474 /* 475 * Free up credentials. 476 */ 477 if (--p->p_cred->p_refcnt == 0) { 478 crfree(p->p_cred->pc_ucred); 479 FREE(p->p_cred, M_SUBPROC); 480 p->p_cred = NULL; 481 } 482 483 /* 484 * Finally finished with old proc entry. 485 * Unlink it from its process group and free it. 486 */ 487 leavepgrp(p); 488 LIST_REMOVE(p, p_list); /* off zombproc */ 489 LIST_REMOVE(p, p_sibling); 490 491 /* 492 * Give machine-dependent layer a chance 493 * to free anything that cpu_exit couldn't 494 * release while still running in process context. 495 */ 496 cpu_wait(p); 497 FREE(p, M_PROC); 498 nprocs--; 499 return (0); 500 } 501 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 502 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 503 p->p_flag |= P_WAITED; 504 retval[0] = p->p_pid; 505 #ifdef COMPAT_43 506 if (compat) { 507 retval[1] = W_STOPCODE(p->p_xstat); 508 error = 0; 509 } else 510 #endif 511 if (uap->status) { 512 status = W_STOPCODE(p->p_xstat); 513 error = copyout((caddr_t)&status, 514 (caddr_t)uap->status, sizeof(status)); 515 } else 516 error = 0; 517 return (error); 518 } 519 } 520 if (nfound == 0) 521 return (ECHILD); 522 if (uap->options & WNOHANG) { 523 retval[0] = 0; 524 return (0); 525 } 526 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 527 return (error); 528 goto loop; 529 } 530 531 /* 532 * make process 'parent' the new parent of process 'child'. 533 */ 534 void 535 proc_reparent(child, parent) 536 register struct proc *child; 537 register struct proc *parent; 538 { 539 540 if (child->p_pptr == parent) 541 return; 542 543 LIST_REMOVE(child, p_sibling); 544 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 545 child->p_pptr = parent; 546 } 547 548 /* 549 * The next two functions are to handle adding/deleting items on the 550 * exit callout list 551 * 552 * at_exit(): 553 * Take the arguments given and put them onto the exit callout list, 554 * However first make sure that it's not already there. 555 * returns 0 on success. 556 */ 557 int 558 at_exit(function) 559 exitlist_fn function; 560 { 561 ele_p ep; 562 563 /* Be noisy if the programmer has lost track of things */ 564 if (rm_at_exit(function)) 565 printf("exit callout entry already present\n"); 566 ep = malloc(sizeof(*ep), M_TEMP, M_NOWAIT); 567 if (ep == NULL) 568 return (ENOMEM); 569 ep->next = exit_list; 570 ep->function = function; 571 exit_list = ep; 572 return (0); 573 } 574 /* 575 * Scan the exit callout list for the given items and remove them. 576 * Returns the number of items removed. 577 * Logically this can only be 0 or 1. 578 */ 579 int 580 rm_at_exit(function) 581 exitlist_fn function; 582 { 583 ele_p *epp, ep; 584 int count; 585 586 count = 0; 587 epp = &exit_list; 588 ep = *epp; 589 while (ep) { 590 if (ep->function == function) { 591 *epp = ep->next; 592 free(ep, M_TEMP); 593 count++; 594 } else { 595 epp = &ep->next; 596 } 597 ep = *epp; 598 } 599 return (count); 600 } 601