kern_exit.c revision 12662
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 1.20 1995/11/11 05:49:22 bde Exp $ 40 */ 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/sysproto.h> 45#include <sys/sysent.h> 46#include <sys/ioctl.h> 47#include <sys/proc.h> 48#include <sys/tty.h> 49#include <sys/time.h> 50#include <sys/resource.h> 51#include <sys/kernel.h> 52#include <sys/buf.h> 53#include <sys/wait.h> 54#include <sys/file.h> 55#include <sys/vnode.h> 56#include <sys/syslog.h> 57#include <sys/malloc.h> 58#include <sys/resourcevar.h> 59#include <sys/signalvar.h> 60#include <sys/ptrace.h> 61#include <sys/shm.h> 62#include <sys/filedesc.h> 63 64#include <machine/cpu.h> 65#ifdef COMPAT_43 66#include <machine/reg.h> 67#include <machine/psl.h> 68#endif 69 70#include <vm/vm.h> 71#include <vm/vm_param.h> 72#include <vm/vm_prot.h> 73#include <vm/lock.h> 74#include <vm/pmap.h> 75#include <vm/vm_map.h> 76#include <vm/vm_kern.h> 77 78static int wait1 __P((struct proc *, struct wait_args *, int [], int)); 79 80/* 81 * exit -- 82 * Death of process. 83 */ 84__dead void 85exit(p, uap, retval) 86 struct proc *p; 87 struct rexit_args /* { 88 int rval; 89 } */ *uap; 90 int *retval; 91{ 92 93 exit1(p, W_EXITCODE(uap->rval, 0)); 94 /* NOTREACHED */ 95} 96 97/* 98 * Exit: deallocate address space and other resources, change proc state 99 * to zombie, and unlink proc from allproc and parent's lists. Save exit 100 * status and rusage for wait(). Check for child processes and orphan them. 101 */ 102__dead void 103exit1(p, rv) 104 register struct proc *p; 105 int rv; 106{ 107 register struct proc *q, *nq; 108 register struct proc **pp; 109 register struct vmspace *vm; 110 111 if (p->p_pid == 1) { 112 printf("init died (signal %d, exit %d)\n", 113 WTERMSIG(rv), WEXITSTATUS(rv)); 114 panic("Going nowhere without my init!"); 115 } 116#ifdef PGINPROF 117 vmsizmon(); 118#endif 119 if (p->p_flag & P_PROFIL) 120 stopprofclock(p); 121 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 122 M_ZOMBIE, M_WAITOK); 123 /* 124 * If parent is waiting for us to exit or exec, 125 * P_PPWAIT is set; we will wakeup the parent below. 126 */ 127 p->p_flag &= ~(P_TRACED | P_PPWAIT); 128 p->p_flag |= P_WEXIT; 129 p->p_sigignore = ~0; 130 p->p_siglist = 0; 131 untimeout(realitexpire, (caddr_t)p); 132 133 /* 134 * Close open files and release open-file table. 135 * This may block! 136 */ 137 fdfree(p); 138 139 /* The next two chunks should probably be moved to vmspace_exit. */ 140 vm = p->p_vmspace; 141#ifdef SYSVSHM 142 if (vm->vm_shm) 143 shmexit(p); 144#endif 145 /* 146 * Release user portion of address space. 147 * This releases references to vnodes, 148 * which could cause I/O if the file has been unlinked. 149 * Need to do this early enough that we can still sleep. 150 * Can't free the entire vmspace as the kernel stack 151 * may be mapped within that space also. 152 */ 153 if (vm->vm_refcnt == 1) 154 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 155 VM_MAXUSER_ADDRESS); 156 157 if (SESS_LEADER(p)) { 158 register struct session *sp = p->p_session; 159 160 if (sp->s_ttyvp) { 161 /* 162 * Controlling process. 163 * Signal foreground pgrp, 164 * drain controlling terminal 165 * and revoke access to controlling terminal. 166 */ 167 if (sp->s_ttyp->t_session == sp) { 168 if (sp->s_ttyp->t_pgrp) 169 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 170 (void) ttywait(sp->s_ttyp); 171 /* 172 * The tty could have been revoked 173 * if we blocked. 174 */ 175 if (sp->s_ttyvp) 176 vgoneall(sp->s_ttyvp); 177 } 178 if (sp->s_ttyvp) 179 vrele(sp->s_ttyvp); 180 sp->s_ttyvp = NULL; 181 /* 182 * s_ttyp is not zero'd; we use this to indicate 183 * that the session once had a controlling terminal. 184 * (for logging and informational purposes) 185 */ 186 } 187 sp->s_leader = NULL; 188 } 189 fixjobc(p, p->p_pgrp, 0); 190 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 191 (void)acct_process(p); 192#ifdef KTRACE 193 /* 194 * release trace file 195 */ 196 p->p_traceflag = 0; /* don't trace the vrele() */ 197 if (p->p_tracep) 198 vrele(p->p_tracep); 199#endif 200 /* 201 * Remove proc from allproc queue and pidhash chain. 202 * Place onto zombproc. Unlink from parent's child list. 203 */ 204 if ((*p->p_prev = p->p_next)) 205 p->p_next->p_prev = p->p_prev; 206 if ((p->p_next = zombproc)) 207 p->p_next->p_prev = &p->p_next; 208 p->p_prev = &zombproc; 209 zombproc = p; 210 p->p_stat = SZOMB; 211 212 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 213 if (*pp == p) { 214 *pp = p->p_hash; 215 goto done; 216 } 217 panic("exit"); 218done: 219 220 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 221 wakeup((caddr_t) initproc); 222 for (q = p->p_cptr; q != NULL; q = nq) { 223 nq = q->p_osptr; 224 if (nq != NULL) 225 nq->p_ysptr = NULL; 226 if (initproc->p_cptr) 227 initproc->p_cptr->p_ysptr = q; 228 q->p_osptr = initproc->p_cptr; 229 q->p_ysptr = NULL; 230 initproc->p_cptr = q; 231 232 q->p_pptr = initproc; 233 /* 234 * Traced processes are killed 235 * since their existence means someone is screwing up. 236 */ 237 if (q->p_flag & P_TRACED) { 238 q->p_flag &= ~P_TRACED; 239 psignal(q, SIGKILL); 240 } 241 } 242 p->p_cptr = NULL; 243 244 /* 245 * Save exit status and final rusage info, adding in child rusage 246 * info and self times. 247 */ 248 p->p_xstat = rv; 249 *p->p_ru = p->p_stats->p_ru; 250 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 251 ruadd(p->p_ru, &p->p_stats->p_cru); 252 253 /* 254 * Notify parent that we're gone. 255 */ 256 psignal(p->p_pptr, SIGCHLD); 257 wakeup((caddr_t)p->p_pptr); 258#if defined(tahoe) 259 /* move this to cpu_exit */ 260 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 261#endif 262 /* 263 * Clear curproc after we've done all operations 264 * that could block, and before tearing down the rest 265 * of the process state that might be used from clock, etc. 266 * Also, can't clear curproc while we're still runnable, 267 * as we're not on a run queue (we are current, just not 268 * a proper proc any longer!). 269 * 270 * Other substructures are freed from wait(). 271 */ 272 curproc = NULL; 273 if (--p->p_limit->p_refcnt == 0) { 274 FREE(p->p_limit, M_SUBPROC); 275 p->p_limit = NULL; 276 } 277 278 /* 279 * Finally, call machine-dependent code to release the remaining 280 * resources including address space, the kernel stack and pcb. 281 * The address space is released by "vmspace_free(p->p_vmspace)"; 282 * This is machine-dependent, as we may have to change stacks 283 * or ensure that the current one isn't reallocated before we 284 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 285 * our execution (pun intended). 286 */ 287 cpu_exit(p); 288} 289 290#ifdef COMPAT_43 291#if defined(hp300) || defined(luna68k) 292#include <machine/frame.h> 293#define GETPS(rp) ((struct frame *)(rp))->f_sr 294#else 295#define GETPS(rp) (rp)[PS] 296#endif 297 298int 299owait(p, uap, retval) 300 struct proc *p; 301 register struct owait_args /* { 302 int dummy; 303 } */ *uap; 304 int *retval; 305{ 306 struct wait_args w; 307 308#ifdef PSL_ALLCC 309 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 310 w.options = 0; 311 w.rusage = NULL; 312 } else { 313 w.options = p->p_md.md_regs[R0]; 314 w.rusage = (struct rusage *)p->p_md.md_regs[R1]; 315 } 316#else 317 w.options = 0; 318 w.rusage = NULL; 319#endif 320 w.pid = WAIT_ANY; 321 w.status = NULL; 322 return (wait1(p, &w, retval, 1)); 323} 324#endif /* COMPAT_43 */ 325 326int 327wait4(p, uap, retval) 328 struct proc *p; 329 struct wait_args *uap; 330 int *retval; 331{ 332 333 return (wait1(p, uap, retval, 0)); 334} 335 336static int 337wait1(q, uap, retval, compat) 338 register struct proc *q; 339 register struct wait_args /* { 340 int pid; 341 int *status; 342 int options; 343 struct rusage *rusage; 344 } */ *uap; 345 int retval[]; 346 int compat; 347{ 348 register int nfound; 349 register struct proc *p, *t; 350 int status, error; 351 352 if (uap->pid == 0) 353 uap->pid = -q->p_pgid; 354#ifdef notyet 355 if (uap->options &~ (WUNTRACED|WNOHANG)) 356 return (EINVAL); 357#endif 358loop: 359 nfound = 0; 360 for (p = q->p_cptr; p; p = p->p_osptr) { 361 if (uap->pid != WAIT_ANY && 362 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 363 continue; 364 nfound++; 365 if (p->p_stat == SZOMB) { 366 /* charge childs scheduling cpu usage to parent */ 367 if (curproc->p_pid != 1) { 368 curproc->p_estcpu = min(curproc->p_estcpu + 369 p->p_estcpu, UCHAR_MAX); 370 } 371 372 retval[0] = p->p_pid; 373#ifdef COMPAT_43 374 if (compat) 375 retval[1] = p->p_xstat; 376 else 377#endif 378 if (uap->status) { 379 status = p->p_xstat; /* convert to int */ 380 if ((error = copyout((caddr_t)&status, 381 (caddr_t)uap->status, sizeof(status)))) 382 return (error); 383 } 384 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 385 (caddr_t)uap->rusage, sizeof (struct rusage)))) 386 return (error); 387 /* 388 * If we got the child via a ptrace 'attach', 389 * we need to give it back to the old parent. 390 */ 391 if (p->p_oppid && (t = pfind(p->p_oppid))) { 392 p->p_oppid = 0; 393 proc_reparent(p, t); 394 psignal(t, SIGCHLD); 395 wakeup((caddr_t)t); 396 return (0); 397 } 398 p->p_xstat = 0; 399 ruadd(&q->p_stats->p_cru, p->p_ru); 400 FREE(p->p_ru, M_ZOMBIE); 401 p->p_ru = NULL; 402 403 /* 404 * Decrement the count of procs running with this uid. 405 */ 406 (void)chgproccnt(p->p_cred->p_ruid, -1); 407 408 /* 409 * Free up credentials. 410 */ 411 if (--p->p_cred->p_refcnt == 0) { 412 crfree(p->p_cred->pc_ucred); 413 FREE(p->p_cred, M_SUBPROC); 414 p->p_cred = NULL; 415 } 416 417 /* 418 * Release reference to text vnode 419 */ 420 if (p->p_textvp) 421 vrele(p->p_textvp); 422 423 /* 424 * Finally finished with old proc entry. 425 * Unlink it from its process group and free it. 426 */ 427 leavepgrp(p); 428 if ((*p->p_prev = p->p_next)) /* off zombproc */ 429 p->p_next->p_prev = p->p_prev; 430 if ((q = p->p_ysptr)) 431 q->p_osptr = p->p_osptr; 432 if ((q = p->p_osptr)) 433 q->p_ysptr = p->p_ysptr; 434 if ((q = p->p_pptr)->p_cptr == p) 435 q->p_cptr = p->p_osptr; 436 437 /* 438 * Give machine-dependent layer a chance 439 * to free anything that cpu_exit couldn't 440 * release while still running in process context. 441 */ 442 cpu_wait(p); 443 FREE(p, M_PROC); 444 nprocs--; 445 return (0); 446 } 447 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 448 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 449 p->p_flag |= P_WAITED; 450 retval[0] = p->p_pid; 451#ifdef COMPAT_43 452 if (compat) { 453 retval[1] = W_STOPCODE(p->p_xstat); 454 error = 0; 455 } else 456#endif 457 if (uap->status) { 458 status = W_STOPCODE(p->p_xstat); 459 error = copyout((caddr_t)&status, 460 (caddr_t)uap->status, sizeof(status)); 461 } else 462 error = 0; 463 return (error); 464 } 465 } 466 if (nfound == 0) 467 return (ECHILD); 468 if (uap->options & WNOHANG) { 469 retval[0] = 0; 470 return (0); 471 } 472 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 473 return (error); 474 goto loop; 475} 476 477/* 478 * make process 'parent' the new parent of process 'child'. 479 */ 480void 481proc_reparent(child, parent) 482 register struct proc *child; 483 register struct proc *parent; 484{ 485 register struct proc *o; 486 register struct proc *y; 487 488 if (child->p_pptr == parent) 489 return; 490 491 /* fix up the child linkage for the old parent */ 492 o = child->p_osptr; 493 y = child->p_ysptr; 494 if (y) 495 y->p_osptr = o; 496 if (o) 497 o->p_ysptr = y; 498 if (child->p_pptr->p_cptr == child) 499 child->p_pptr->p_cptr = o; 500 501 /* fix up child linkage for new parent */ 502 o = parent->p_cptr; 503 if (o) 504 o->p_ysptr = child; 505 child->p_osptr = o; 506 child->p_ysptr = NULL; 507 parent->p_cptr = child; 508 child->p_pptr = parent; 509} 510