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 1.55 1997/09/13 19:42:10 joerg 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/proc.h> 48 #include <sys/tty.h> 49 #include <sys/wait.h> 50 #include <sys/vnode.h> 51 #include <sys/malloc.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 int wait1 __P((struct proc *, struct wait_args *, int [], int)); 74 75 /* 76 * callout list for things to do at exit time 77 */ 78 typedef struct exit_list_element { 79 struct exit_list_element *next; 80 exitlist_fn function; 81 } *ele_p; 82 83 static ele_p exit_list; 84 85 /* 86 * exit -- 87 * Death of process. 88 */ 89 void 90 exit(p, uap, retval) 91 struct proc *p; 92 struct rexit_args /* { 93 int rval; 94 } */ *uap; 95 int *retval; 96 { 97 98 exit1(p, W_EXITCODE(uap->rval, 0)); 99 /* NOTREACHED */ 100 } 101 102 /* 103 * Exit: deallocate address space and other resources, change proc state 104 * to zombie, and unlink proc from allproc and parent's lists. Save exit 105 * status and rusage for wait(). Check for child processes and orphan them. 106 */ 107 void 108 exit1(p, rv) 109 register struct proc *p; 110 int rv; 111 { 112 register struct proc *q, *nq; 113 register struct vmspace *vm; 114 ele_p ep = exit_list; 115 116 if (p->p_pid == 1) { 117 printf("init died (signal %d, exit %d)\n", 118 WTERMSIG(rv), WEXITSTATUS(rv)); 119 panic("Going nowhere without my init!"); 120 } 121 122 aio_proc_rundown(p); 123 124 /* are we a task leader? */ 125 if(p == p->p_leader) { 126 struct kill_args killArgs; 127 killArgs.signum = SIGKILL; 128 q = p->p_peers; 129 while(q) { 130 killArgs.pid = q->p_pid; 131 /* 132 * The interface for kill is better 133 * than the internal signal 134 */ 135 kill(p, &killArgs, &rv); 136 nq = q; 137 q = q->p_peers; 138 /* 139 * orphan the threads so we don't mess up 140 * when they call exit 141 */ 142 nq->p_peers = 0; 143 nq->p_leader = nq; 144 } 145 146 /* otherwise are we a peer? */ 147 } else if(p->p_peers) { 148 q = p->p_leader; 149 while(q->p_peers != p) 150 q = q->p_peers; 151 q->p_peers = p->p_peers; 152 } 153 154 #ifdef PGINPROF 155 vmsizmon(); 156 #endif 157 /* 158 * Check if any LKMs need anything done at process exit. 159 * e.g. SYSV IPC stuff 160 * XXX what if one of these generates an error? 161 */ 162 while (ep) { 163 (*ep->function)(p); 164 ep = ep->next; 165 } 166 167 if (p->p_flag & P_PROFIL) 168 stopprofclock(p); 169 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 170 M_ZOMBIE, M_WAITOK); 171 /* 172 * If parent is waiting for us to exit or exec, 173 * P_PPWAIT is set; we will wakeup the parent below. 174 */ 175 p->p_flag &= ~(P_TRACED | P_PPWAIT); 176 p->p_flag |= P_WEXIT; 177 p->p_sigignore = ~0; 178 p->p_siglist = 0; 179 if (timerisset(&p->p_realtimer.it_value)) 180 untimeout(realitexpire, (caddr_t)p, p->p_ithandle); 181 182 /* 183 * Close open files and release open-file table. 184 * This may block! 185 */ 186 fdfree(p); 187 188 /* 189 * XXX Shutdown SYSV semaphores 190 */ 191 semexit(p); 192 193 /* The next two chunks should probably be moved to vmspace_exit. */ 194 vm = p->p_vmspace; 195 /* 196 * Release user portion of address space. 197 * This releases references to vnodes, 198 * which could cause I/O if the file has been unlinked. 199 * Need to do this early enough that we can still sleep. 200 * Can't free the entire vmspace as the kernel stack 201 * may be mapped within that space also. 202 */ 203 if (vm->vm_refcnt == 1) { 204 if (vm->vm_shm) 205 shmexit(p); 206 pmap_remove_pages(&vm->vm_pmap, VM_MIN_ADDRESS, 207 VM_MAXUSER_ADDRESS); 208 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 209 VM_MAXUSER_ADDRESS); 210 } 211 212 if (SESS_LEADER(p)) { 213 register struct session *sp = p->p_session; 214 215 if (sp->s_ttyvp) { 216 /* 217 * Controlling process. 218 * Signal foreground pgrp, 219 * drain controlling terminal 220 * and revoke access to controlling terminal. 221 */ 222 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 223 if (sp->s_ttyp->t_pgrp) 224 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 225 (void) ttywait(sp->s_ttyp); 226 /* 227 * The tty could have been revoked 228 * if we blocked. 229 */ 230 if (sp->s_ttyvp) 231 VOP_REVOKE(sp->s_ttyvp, REVOKEALL); 232 } 233 if (sp->s_ttyvp) 234 vrele(sp->s_ttyvp); 235 sp->s_ttyvp = NULL; 236 /* 237 * s_ttyp is not zero'd; we use this to indicate 238 * that the session once had a controlling terminal. 239 * (for logging and informational purposes) 240 */ 241 } 242 sp->s_leader = NULL; 243 } 244 fixjobc(p, p->p_pgrp, 0); 245 if (p->p_limit->p_refcnt > 1 && 246 (p->p_limit->p_lflags & PL_SHAREMOD) == 0) { 247 p->p_limit->p_refcnt--; 248 p->p_limit = limcopy(p->p_limit); 249 } 250 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 251 (void)acct_process(p); 252 #ifdef KTRACE 253 /* 254 * release trace file 255 */ 256 p->p_traceflag = 0; /* don't trace the vrele() */ 257 if (p->p_tracep) 258 vrele(p->p_tracep); 259 #endif 260 /* 261 * Remove proc from allproc queue and pidhash chain. 262 * Place onto zombproc. Unlink from parent's child list. 263 */ 264 LIST_REMOVE(p, p_list); 265 LIST_INSERT_HEAD(&zombproc, p, p_list); 266 p->p_stat = SZOMB; 267 268 LIST_REMOVE(p, p_hash); 269 270 q = p->p_children.lh_first; 271 if (q) /* only need this if any child is S_ZOMB */ 272 wakeup((caddr_t) initproc); 273 for (; q != 0; q = nq) { 274 nq = q->p_sibling.le_next; 275 LIST_REMOVE(q, p_sibling); 276 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling); 277 q->p_pptr = initproc; 278 /* 279 * Traced processes are killed 280 * since their existence means someone is screwing up. 281 */ 282 if (q->p_flag & P_TRACED) { 283 q->p_flag &= ~P_TRACED; 284 psignal(q, SIGKILL); 285 } 286 } 287 288 /* 289 * Save exit status and final rusage info, adding in child rusage 290 * info and self times. 291 */ 292 p->p_xstat = rv; 293 *p->p_ru = p->p_stats->p_ru; 294 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 295 ruadd(p->p_ru, &p->p_stats->p_cru); 296 297 /* 298 * Notify parent that we're gone. If parent has the P_NOCLDWAIT 299 * flag set, notify process 1 instead (and hope it will handle 300 * this situation). 301 */ 302 if (p->p_pptr->p_flag & P_NOCLDWAIT) { 303 struct proc *pp = p->p_pptr; 304 proc_reparent(p, initproc); 305 /* 306 * If this was the last child of our parent, notify 307 * parent, so in case he was wait(2)ing, he will 308 * continue. 309 */ 310 if (LIST_EMPTY(&pp->p_children)) 311 wakeup((caddr_t)pp); 312 } 313 314 psignal(p->p_pptr, SIGCHLD); 315 wakeup((caddr_t)p->p_pptr); 316 #if defined(tahoe) 317 /* move this to cpu_exit */ 318 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 319 #endif 320 /* 321 * Clear curproc after we've done all operations 322 * that could block, and before tearing down the rest 323 * of the process state that might be used from clock, etc. 324 * Also, can't clear curproc while we're still runnable, 325 * as we're not on a run queue (we are current, just not 326 * a proper proc any longer!). 327 * 328 * Other substructures are freed from wait(). 329 */ 330 curproc = NULL; 331 if (--p->p_limit->p_refcnt == 0) { 332 FREE(p->p_limit, M_SUBPROC); 333 p->p_limit = NULL; 334 } 335 336 /* 337 * Finally, call machine-dependent code to release the remaining 338 * resources including address space, the kernel stack and pcb. 339 * The address space is released by "vmspace_free(p->p_vmspace)"; 340 * This is machine-dependent, as we may have to change stacks 341 * or ensure that the current one isn't reallocated before we 342 * finish. cpu_exit will end with a call to cpu_switch(), finishing 343 * our execution (pun intended). 344 */ 345 cpu_exit(p); 346 } 347 348 #ifdef COMPAT_43 349 #if defined(hp300) || defined(luna68k) 350 #include <machine/frame.h> 351 #define GETPS(rp) ((struct frame *)(rp))->f_sr 352 #else 353 #define GETPS(rp) (rp)[PS] 354 #endif 355 356 int 357 owait(p, uap, retval) 358 struct proc *p; 359 register struct owait_args /* { 360 int dummy; 361 } */ *uap; 362 int *retval; 363 { 364 struct wait_args w; 365 366 #ifdef PSL_ALLCC 367 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 368 w.options = 0; 369 w.rusage = NULL; 370 } else { 371 w.options = p->p_md.md_regs[R0]; 372 w.rusage = (struct rusage *)p->p_md.md_regs[R1]; 373 } 374 #else 375 w.options = 0; 376 w.rusage = NULL; 377 #endif 378 w.pid = WAIT_ANY; 379 w.status = NULL; 380 return (wait1(p, &w, retval, 1)); 381 } 382 #endif /* COMPAT_43 */ 383 384 int 385 wait4(p, uap, retval) 386 struct proc *p; 387 struct wait_args *uap; 388 int *retval; 389 { 390 391 return (wait1(p, uap, retval, 0)); 392 } 393 394 static int 395 wait1(q, uap, retval, compat) 396 register struct proc *q; 397 register struct wait_args /* { 398 int pid; 399 int *status; 400 int options; 401 struct rusage *rusage; 402 } */ *uap; 403 int retval[]; 404 int compat; 405 { 406 register int nfound; 407 register struct proc *p, *t; 408 int status, error; 409 410 if (uap->pid == 0) 411 uap->pid = -q->p_pgid; 412 #ifdef notyet 413 if (uap->options &~ (WUNTRACED|WNOHANG)) 414 return (EINVAL); 415 #endif 416 loop: 417 nfound = 0; 418 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 419 if (uap->pid != WAIT_ANY && 420 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 421 continue; 422 nfound++; 423 if (p->p_stat == SZOMB) { 424 /* charge childs scheduling cpu usage to parent */ 425 if (curproc->p_pid != 1) { 426 curproc->p_estcpu = min(curproc->p_estcpu + 427 p->p_estcpu, UCHAR_MAX); 428 } 429 430 retval[0] = p->p_pid; 431 #ifdef COMPAT_43 432 if (compat) 433 retval[1] = p->p_xstat; 434 else 435 #endif 436 if (uap->status) { 437 status = p->p_xstat; /* convert to int */ 438 if ((error = copyout((caddr_t)&status, 439 (caddr_t)uap->status, sizeof(status)))) 440 return (error); 441 } 442 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 443 (caddr_t)uap->rusage, sizeof (struct rusage)))) 444 return (error); 445 /* 446 * If we got the child via a ptrace 'attach', 447 * we need to give it back to the old parent. 448 */ 449 if (p->p_oppid && (t = pfind(p->p_oppid))) { 450 p->p_oppid = 0; 451 proc_reparent(p, t); 452 psignal(t, SIGCHLD); 453 wakeup((caddr_t)t); 454 return (0); 455 } 456 p->p_xstat = 0; 457 ruadd(&q->p_stats->p_cru, p->p_ru); 458 FREE(p->p_ru, M_ZOMBIE); 459 p->p_ru = NULL; 460 461 /* 462 * Decrement the count of procs running with this uid. 463 */ 464 (void)chgproccnt(p->p_cred->p_ruid, -1); 465 466 /* 467 * Release reference to text vnode 468 */ 469 if (p->p_textvp) 470 vrele(p->p_textvp); 471 472 /* 473 * Free up credentials. 474 */ 475 if (--p->p_cred->p_refcnt == 0) { 476 crfree(p->p_cred->pc_ucred); 477 FREE(p->p_cred, M_SUBPROC); 478 p->p_cred = NULL; 479 } 480 481 /* 482 * Finally finished with old proc entry. 483 * Unlink it from its process group and free it. 484 */ 485 leavepgrp(p); 486 LIST_REMOVE(p, p_list); /* off zombproc */ 487 LIST_REMOVE(p, p_sibling); 488 489 /* 490 * Give machine-dependent layer a chance 491 * to free anything that cpu_exit couldn't 492 * release while still running in process context. 493 */ 494 cpu_wait(p); 495 FREE(p, M_PROC); 496 nprocs--; 497 return (0); 498 } 499 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 500 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 501 p->p_flag |= P_WAITED; 502 retval[0] = p->p_pid; 503 #ifdef COMPAT_43 504 if (compat) { 505 retval[1] = W_STOPCODE(p->p_xstat); 506 error = 0; 507 } else 508 #endif 509 if (uap->status) { 510 status = W_STOPCODE(p->p_xstat); 511 error = copyout((caddr_t)&status, 512 (caddr_t)uap->status, sizeof(status)); 513 } else 514 error = 0; 515 return (error); 516 } 517 } 518 if (nfound == 0) 519 return (ECHILD); 520 if (uap->options & WNOHANG) { 521 retval[0] = 0; 522 return (0); 523 } 524 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 525 return (error); 526 goto loop; 527 } 528 529 /* 530 * make process 'parent' the new parent of process 'child'. 531 */ 532 void 533 proc_reparent(child, parent) 534 register struct proc *child; 535 register struct proc *parent; 536 { 537 538 if (child->p_pptr == parent) 539 return; 540 541 LIST_REMOVE(child, p_sibling); 542 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 543 child->p_pptr = parent; 544 } 545 546 /* 547 * The next two functions are to handle adding/deleting items on the 548 * exit callout list 549 * 550 * at_exit(): 551 * Take the arguments given and put them onto the exit callout list, 552 * However first make sure that it's not already there. 553 * returns 0 on success. 554 */ 555 int 556 at_exit(function) 557 exitlist_fn function; 558 { 559 ele_p ep; 560 561 /* Be noisy if the programmer has lost track of things */ 562 if (rm_at_exit(function)) 563 printf("exit callout entry already present\n"); 564 ep = malloc(sizeof(*ep), M_TEMP, M_NOWAIT); 565 if (ep == NULL) 566 return (ENOMEM); 567 ep->next = exit_list; 568 ep->function = function; 569 exit_list = ep; 570 return (0); 571 } 572 /* 573 * Scan the exit callout list for the given items and remove them. 574 * Returns the number of items removed. 575 * Logically this can only be 0 or 1. 576 */ 577 int 578 rm_at_exit(function) 579 exitlist_fn function; 580 { 581 ele_p *epp, ep; 582 int count; 583 584 count = 0; 585 epp = &exit_list; 586 ep = *epp; 587 while (ep) { 588 if (ep->function == function) { 589 *epp = ep->next; 590 free(ep, M_TEMP); 591 count++; 592 } else { 593 epp = &ep->next; 594 } 595 ep = *epp; 596 } 597 return (count); 598 } 599