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 1.70 1998/12/19 02:55:33 julian Exp $ 40 */ 41 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/sysproto.h> 48 #include <sys/kernel.h> 49 #include <sys/malloc.h> 50 #include <sys/proc.h> 51 #include <sys/pioctl.h> 52 #include <sys/tty.h> 53 #include <sys/wait.h> 54 #include <sys/vnode.h> 55 #include <sys/resourcevar.h> 56 #include <sys/signalvar.h> 57 #include <sys/ptrace.h> 58 #include <sys/acct.h> /* for acct_process() function prototype */ 59 #include <sys/filedesc.h> 60 #include <sys/shm.h> 61 #include <sys/sem.h> 62 #include <sys/aio.h> 63 64 #ifdef COMPAT_43 65 #include <machine/reg.h> 66 #include <machine/psl.h> 67 #endif 68 #include <machine/limits.h> /* for UCHAR_MAX = typeof(p_priority)_MAX */ 69 70 #include <vm/vm.h> 71 #include <vm/vm_param.h> 72 #include <sys/lock.h> 73 #include <vm/pmap.h> 74 #include <vm/vm_map.h> 75 #include <vm/vm_zone.h> 76 #ifdef COMPAT_LINUX_THREADS 77 #include <sys/user.h> 78 #endif 79 80 static MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 81 82 static int wait1 __P((struct proc *, struct wait_args *, int)); 83 84 /* 85 * callout list for things to do at exit time 86 */ 87 typedef struct exit_list_element { 88 struct exit_list_element *next; 89 exitlist_fn function; 90 } *ele_p; 91 92 static ele_p exit_list; 93 94 /* 95 * exit -- 96 * Death of process. 97 */ 98 void 99 exit(p, uap) 100 struct proc *p; 101 struct rexit_args /* { 102 int rval; 103 } */ *uap; 104 { 105 106 exit1(p, W_EXITCODE(uap->rval, 0)); 107 /* NOTREACHED */ 108 } 109 110 /* 111 * Exit: deallocate address space and other resources, change proc state 112 * to zombie, and unlink proc from allproc and parent's lists. Save exit 113 * status and rusage for wait(). Check for child processes and orphan them. 114 */ 115 void 116 exit1(p, rv) 117 register struct proc *p; 118 int rv; 119 { 120 register struct proc *q, *nq; 121 register struct vmspace *vm; 122 ele_p ep = exit_list; 123 124 if (p->p_pid == 1) { 125 printf("init died (signal %d, exit %d)\n", 126 WTERMSIG(rv), WEXITSTATUS(rv)); 127 panic("Going nowhere without my init!"); 128 } 129 130 aio_proc_rundown(p); 131 132 /* are we a task leader? */ 133 if(p == p->p_leader) { 134 struct kill_args killArgs; 135 killArgs.signum = SIGKILL; 136 q = p->p_peers; 137 while(q) { 138 killArgs.pid = q->p_pid; 139 /* 140 * The interface for kill is better 141 * than the internal signal 142 */ 143 kill(p, &killArgs); 144 nq = q; 145 q = q->p_peers; 146 /* 147 * orphan the threads so we don't mess up 148 * when they call exit 149 */ 150 nq->p_peers = 0; 151 nq->p_leader = nq; 152 } 153 154 /* otherwise are we a peer? */ 155 } else if(p->p_peers) { 156 q = p->p_leader; 157 while(q->p_peers != p) 158 q = q->p_peers; 159 q->p_peers = p->p_peers; 160 } 161 162 #ifdef PGINPROF 163 vmsizmon(); 164 #endif 165 STOPEVENT(p, S_EXIT, rv); 166 167 /* 168 * Check if any LKMs need anything done at process exit. 169 * e.g. SYSV IPC stuff 170 * XXX what if one of these generates an error? 171 */ 172 while (ep) { 173 (*ep->function)(p); 174 ep = ep->next; 175 } 176 177 if (p->p_flag & P_PROFIL) 178 stopprofclock(p); 179 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 180 M_ZOMBIE, M_WAITOK); 181 /* 182 * If parent is waiting for us to exit or exec, 183 * P_PPWAIT is set; we will wakeup the parent below. 184 */ 185 p->p_flag &= ~(P_TRACED | P_PPWAIT); 186 p->p_flag |= P_WEXIT; 187 #ifndef COMPAT_LINUX_THREADS 188 p->p_sigignore = ~0; 189 #endif /* COMPAT_LINUX_THREADS */ 190 p->p_siglist = 0; 191 if (timevalisset(&p->p_realtimer.it_value)) 192 untimeout(realitexpire, (caddr_t)p, p->p_ithandle); 193 194 /* 195 * Reset any sigio structures pointing to us as a result of 196 * F_SETOWN with our pid. 197 */ 198 funsetownlst(&p->p_sigiolst); 199 200 /* 201 * Close open files and release open-file table. 202 * This may block! 203 */ 204 fdfree(p); 205 206 /* 207 * XXX Shutdown SYSV semaphores 208 */ 209 semexit(p); 210 211 /* The next two chunks should probably be moved to vmspace_exit. */ 212 vm = p->p_vmspace; 213 /* 214 * Release user portion of address space. 215 * This releases references to vnodes, 216 * which could cause I/O if the file has been unlinked. 217 * Need to do this early enough that we can still sleep. 218 * Can't free the entire vmspace as the kernel stack 219 * may be mapped within that space also. 220 */ 221 if (vm->vm_refcnt == 1) { 222 if (vm->vm_shm) 223 shmexit(p); 224 pmap_remove_pages(&vm->vm_pmap, VM_MIN_ADDRESS, 225 VM_MAXUSER_ADDRESS); 226 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 227 VM_MAXUSER_ADDRESS); 228 } 229 230 if (SESS_LEADER(p)) { 231 register struct session *sp = p->p_session; 232 233 if (sp->s_ttyvp) { 234 /* 235 * Controlling process. 236 * Signal foreground pgrp, 237 * drain controlling terminal 238 * and revoke access to controlling terminal. 239 */ 240 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 241 if (sp->s_ttyp->t_pgrp) 242 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 243 (void) ttywait(sp->s_ttyp); 244 /* 245 * The tty could have been revoked 246 * if we blocked. 247 */ 248 if (sp->s_ttyvp) 249 VOP_REVOKE(sp->s_ttyvp, REVOKEALL); 250 } 251 if (sp->s_ttyvp) 252 vrele(sp->s_ttyvp); 253 sp->s_ttyvp = NULL; 254 /* 255 * s_ttyp is not zero'd; we use this to indicate 256 * that the session once had a controlling terminal. 257 * (for logging and informational purposes) 258 */ 259 } 260 sp->s_leader = NULL; 261 } 262 fixjobc(p, p->p_pgrp, 0); 263 (void)acct_process(p); 264 #ifdef KTRACE 265 /* 266 * release trace file 267 */ 268 p->p_traceflag = 0; /* don't trace the vrele() */ 269 if (p->p_tracep) 270 vrele(p->p_tracep); 271 #endif 272 /* 273 * Remove proc from allproc queue and pidhash chain. 274 * Place onto zombproc. Unlink from parent's child list. 275 */ 276 LIST_REMOVE(p, p_list); 277 LIST_INSERT_HEAD(&zombproc, p, p_list); 278 p->p_stat = SZOMB; 279 280 LIST_REMOVE(p, p_hash); 281 282 q = p->p_children.lh_first; 283 if (q) /* only need this if any child is S_ZOMB */ 284 wakeup((caddr_t) initproc); 285 for (; q != 0; q = nq) { 286 nq = q->p_sibling.le_next; 287 LIST_REMOVE(q, p_sibling); 288 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling); 289 q->p_pptr = initproc; 290 #ifdef COMPAT_LINUX_THREADS 291 q->p_sigparent = 0; 292 #endif /* COMPAT_LINUX_THREADS */ 293 /* 294 * Traced processes are killed 295 * since their existence means someone is screwing up. 296 */ 297 if (q->p_flag & P_TRACED) { 298 q->p_flag &= ~P_TRACED; 299 psignal(q, SIGKILL); 300 } 301 } 302 303 /* 304 * Save exit status and final rusage info, adding in child rusage 305 * info and self times. 306 */ 307 p->p_xstat = rv; 308 *p->p_ru = p->p_stats->p_ru; 309 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 310 ruadd(p->p_ru, &p->p_stats->p_cru); 311 312 /* 313 * Notify parent that we're gone. If parent has the P_NOCLDWAIT 314 * flag set, notify process 1 instead (and hope it will handle 315 * this situation). 316 */ 317 #ifndef COMPAT_LINUX_THREADS 318 if (p->p_pptr->p_flag & P_NOCLDWAIT) { 319 #else 320 if (p->p_pptr->p_procsig->ps_flag & P_NOCLDWAIT) { 321 #endif /* COMPAT_LINUX_THREADS */ 322 struct proc *pp = p->p_pptr; 323 proc_reparent(p, initproc); 324 /* 325 * If this was the last child of our parent, notify 326 * parent, so in case he was wait(2)ing, he will 327 * continue. 328 */ 329 if (LIST_EMPTY(&pp->p_children)) 330 wakeup((caddr_t)pp); 331 } 332 333 #ifndef COMPAT_LINUX_THREADS 334 psignal(p->p_pptr, SIGCHLD); 335 #else 336 if (p->p_sigparent && p->p_pptr != initproc) { 337 psignal(p->p_pptr, p->p_sigparent); 338 } else { 339 psignal(p->p_pptr, SIGCHLD); 340 } 341 #endif /* COMPAT_LINUX_THREADS */ 342 wakeup((caddr_t)p->p_pptr); 343 #if defined(tahoe) 344 /* move this to cpu_exit */ 345 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 346 #endif 347 /* 348 * Clear curproc after we've done all operations 349 * that could block, and before tearing down the rest 350 * of the process state that might be used from clock, etc. 351 * Also, can't clear curproc while we're still runnable, 352 * as we're not on a run queue (we are current, just not 353 * a proper proc any longer!). 354 * 355 * Other substructures are freed from wait(). 356 */ 357 curproc = NULL; 358 if (--p->p_limit->p_refcnt == 0) { 359 FREE(p->p_limit, M_SUBPROC); 360 p->p_limit = NULL; 361 } 362 363 /* 364 * Finally, call machine-dependent code to release the remaining 365 * resources including address space, the kernel stack and pcb. 366 * The address space is released by "vmspace_free(p->p_vmspace)"; 367 * This is machine-dependent, as we may have to change stacks 368 * or ensure that the current one isn't reallocated before we 369 * finish. cpu_exit will end with a call to cpu_switch(), finishing 370 * our execution (pun intended). 371 */ 372 cpu_exit(p); 373 } 374 375 #ifdef COMPAT_43 376 #if defined(hp300) || defined(luna68k) 377 #include <machine/frame.h> 378 #define GETPS(rp) ((struct frame *)(rp))->f_sr 379 #else 380 #define GETPS(rp) (rp)[PS] 381 #endif 382 383 int 384 owait(p, uap) 385 struct proc *p; 386 register struct owait_args /* { 387 int dummy; 388 } */ *uap; 389 { 390 struct wait_args w; 391 392 #ifdef PSL_ALLCC 393 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 394 w.options = 0; 395 w.rusage = NULL; 396 } else { 397 w.options = p->p_md.md_regs[R0]; 398 w.rusage = (struct rusage *)p->p_md.md_regs[R1]; 399 } 400 #else 401 w.options = 0; 402 w.rusage = NULL; 403 #endif 404 w.pid = WAIT_ANY; 405 w.status = NULL; 406 return (wait1(p, &w, 1)); 407 } 408 #endif /* COMPAT_43 */ 409 410 int 411 wait4(p, uap) 412 struct proc *p; 413 struct wait_args *uap; 414 { 415 416 return (wait1(p, uap, 0)); 417 } 418 419 static int 420 wait1(q, uap, compat) 421 register struct proc *q; 422 register struct wait_args /* { 423 int pid; 424 int *status; 425 int options; 426 struct rusage *rusage; 427 } */ *uap; 428 int compat; 429 { 430 register int nfound; 431 register struct proc *p, *t; 432 int status, error; 433 434 if (uap->pid == 0) 435 uap->pid = -q->p_pgid; 436 if (uap->options &~ (WUNTRACED|WNOHANG)) 437 return (EINVAL); 438 loop: 439 nfound = 0; 440 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 441 if (uap->pid != WAIT_ANY && 442 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 443 continue; 444 nfound++; 445 if (p->p_stat == SZOMB) { 446 /* charge childs scheduling cpu usage to parent */ 447 if (curproc->p_pid != 1) { 448 curproc->p_estcpu = min(curproc->p_estcpu + 449 p->p_estcpu, UCHAR_MAX); 450 } 451 452 q->p_retval[0] = p->p_pid; 453 #ifdef COMPAT_43 454 if (compat) 455 q->p_retval[1] = p->p_xstat; 456 else 457 #endif 458 if (uap->status) { 459 status = p->p_xstat; /* convert to int */ 460 if ((error = copyout((caddr_t)&status, 461 (caddr_t)uap->status, sizeof(status)))) 462 return (error); 463 } 464 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 465 (caddr_t)uap->rusage, sizeof (struct rusage)))) 466 return (error); 467 /* 468 * If we got the child via a ptrace 'attach', 469 * we need to give it back to the old parent. 470 */ 471 if (p->p_oppid && (t = pfind(p->p_oppid))) { 472 p->p_oppid = 0; 473 proc_reparent(p, t); 474 psignal(t, SIGCHLD); 475 wakeup((caddr_t)t); 476 return (0); 477 } 478 p->p_xstat = 0; 479 ruadd(&q->p_stats->p_cru, p->p_ru); 480 FREE(p->p_ru, M_ZOMBIE); 481 p->p_ru = NULL; 482 483 /* 484 * Decrement the count of procs running with this uid. 485 */ 486 (void)chgproccnt(p->p_cred->p_ruid, -1); 487 488 /* 489 * Release reference to text vnode 490 */ 491 if (p->p_textvp) 492 vrele(p->p_textvp); 493 494 /* 495 * Free up credentials. 496 */ 497 if (--p->p_cred->p_refcnt == 0) { 498 crfree(p->p_cred->pc_ucred); 499 FREE(p->p_cred, M_SUBPROC); 500 p->p_cred = NULL; 501 } 502 503 /* 504 * Finally finished with old proc entry. 505 * Unlink it from its process group and free it. 506 */ 507 leavepgrp(p); 508 LIST_REMOVE(p, p_list); /* off zombproc */ 509 LIST_REMOVE(p, p_sibling); 510 511 #ifdef COMPAT_LINUX_THREADS 512 if (--p->p_procsig->ps_refcnt == 0) { 513 if (p->p_sigacts != &p->p_addr->u_sigacts) 514 FREE(p->p_sigacts, M_SUBPROC); 515 FREE(p->p_procsig, M_SUBPROC); 516 p->p_procsig = NULL; 517 } 518 #endif /* COMPAT_LINUX_THREADS */ 519 /* 520 * Give machine-dependent layer a chance 521 * to free anything that cpu_exit couldn't 522 * release while still running in process context. 523 */ 524 cpu_wait(p); 525 zfree(proc_zone, p); 526 nprocs--; 527 return (0); 528 } 529 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 530 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 531 p->p_flag |= P_WAITED; 532 q->p_retval[0] = p->p_pid; 533 #ifdef COMPAT_43 534 if (compat) { 535 q->p_retval[1] = W_STOPCODE(p->p_xstat); 536 error = 0; 537 } else 538 #endif 539 if (uap->status) { 540 status = W_STOPCODE(p->p_xstat); 541 error = copyout((caddr_t)&status, 542 (caddr_t)uap->status, sizeof(status)); 543 } else 544 error = 0; 545 return (error); 546 } 547 } 548 if (nfound == 0) 549 return (ECHILD); 550 if (uap->options & WNOHANG) { 551 q->p_retval[0] = 0; 552 return (0); 553 } 554 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 555 return (error); 556 goto loop; 557 } 558 559 /* 560 * make process 'parent' the new parent of process 'child'. 561 */ 562 void 563 proc_reparent(child, parent) 564 register struct proc *child; 565 register struct proc *parent; 566 { 567 568 if (child->p_pptr == parent) 569 return; 570 571 LIST_REMOVE(child, p_sibling); 572 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 573 child->p_pptr = parent; 574 } 575 576 /* 577 * The next two functions are to handle adding/deleting items on the 578 * exit callout list 579 * 580 * at_exit(): 581 * Take the arguments given and put them onto the exit callout list, 582 * However first make sure that it's not already there. 583 * returns 0 on success. 584 */ 585 int 586 at_exit(function) 587 exitlist_fn function; 588 { 589 ele_p ep; 590 591 /* Be noisy if the programmer has lost track of things */ 592 if (rm_at_exit(function)) 593 printf("exit callout entry already present\n"); 594 ep = malloc(sizeof(*ep), M_TEMP, M_NOWAIT); 595 if (ep == NULL) 596 return (ENOMEM); 597 ep->next = exit_list; 598 ep->function = function; 599 exit_list = ep; 600 return (0); 601 } 602 /* 603 * Scan the exit callout list for the given items and remove them. 604 * Returns the number of items removed. 605 * Logically this can only be 0 or 1. 606 */ 607 int 608 rm_at_exit(function) 609 exitlist_fn function; 610 { 611 ele_p *epp, ep; 612 int count; 613 614 count = 0; 615 epp = &exit_list; 616 ep = *epp; 617 while (ep) { 618 if (ep->function == function) { 619 *epp = ep->next; 620 free(ep, M_TEMP); 621 count++; 622 } else { 623 epp = &ep->next; 624 } 625 ep = *epp; 626 } 627 return (count); 628 } 629 630 #ifdef COMPAT_LINUX_THREADS 631 void check_sigacts (void) 632 { 633 struct proc *p = curproc; 634 struct sigacts *pss; 635 int s; 636 637 if (p->p_procsig->ps_refcnt == 1 && 638 p->p_sigacts != &p->p_addr->u_sigacts) { 639 pss = p->p_sigacts; 640 s = splhigh(); 641 p->p_addr->u_sigacts = *pss; 642 p->p_sigacts = &p->p_addr->u_sigacts; 643 splx(s); 644 FREE(pss, M_SUBPROC); 645 } 646 } 647 #endif 648