kern_exit.c revision 11733
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 1.18 1995/10/23 15:42:09 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_kern.h> 72 73static int wait1 __P((struct proc *, struct wait_args *, int [], int)); 74 75/* 76 * exit -- 77 * Death of process. 78 */ 79__dead void 80exit(p, uap, retval) 81 struct proc *p; 82 struct rexit_args /* { 83 int rval; 84 } */ *uap; 85 int *retval; 86{ 87 88 exit1(p, W_EXITCODE(uap->rval, 0)); 89 /* NOTREACHED */ 90 while (1); 91} 92 93/* 94 * Exit: deallocate address space and other resources, change proc state 95 * to zombie, and unlink proc from allproc and parent's lists. Save exit 96 * status and rusage for wait(). Check for child processes and orphan them. 97 */ 98__dead void 99exit1(p, rv) 100 register struct proc *p; 101 int rv; 102{ 103 register struct proc *q, *nq; 104 register struct proc **pp; 105 register struct vmspace *vm; 106 107 if (p->p_pid == 1) { 108 printf("init died (signal %d, exit %d)\n", 109 WTERMSIG(rv), WEXITSTATUS(rv)); 110 panic("Going nowhere without my init!"); 111 } 112#ifdef PGINPROF 113 vmsizmon(); 114#endif 115 if (p->p_flag & P_PROFIL) 116 stopprofclock(p); 117 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 118 M_ZOMBIE, M_WAITOK); 119 /* 120 * If parent is waiting for us to exit or exec, 121 * P_PPWAIT is set; we will wakeup the parent below. 122 */ 123 p->p_flag &= ~(P_TRACED | P_PPWAIT); 124 p->p_flag |= P_WEXIT; 125 p->p_sigignore = ~0; 126 p->p_siglist = 0; 127 untimeout(realitexpire, (caddr_t)p); 128 129 /* 130 * Close open files and release open-file table. 131 * This may block! 132 */ 133 fdfree(p); 134 135 /* The next two chunks should probably be moved to vmspace_exit. */ 136 vm = p->p_vmspace; 137#ifdef SYSVSHM 138 if (vm->vm_shm) 139 shmexit(p); 140#endif 141 /* 142 * Release user portion of address space. 143 * This releases references to vnodes, 144 * which could cause I/O if the file has been unlinked. 145 * Need to do this early enough that we can still sleep. 146 * Can't free the entire vmspace as the kernel stack 147 * may be mapped within that space also. 148 */ 149 if (vm->vm_refcnt == 1) 150 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 151 VM_MAXUSER_ADDRESS); 152 153 if (SESS_LEADER(p)) { 154 register struct session *sp = p->p_session; 155 156 if (sp->s_ttyvp) { 157 /* 158 * Controlling process. 159 * Signal foreground pgrp, 160 * drain controlling terminal 161 * and revoke access to controlling terminal. 162 */ 163 if (sp->s_ttyp->t_session == sp) { 164 if (sp->s_ttyp->t_pgrp) 165 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 166 (void) ttywait(sp->s_ttyp); 167 /* 168 * The tty could have been revoked 169 * if we blocked. 170 */ 171 if (sp->s_ttyvp) 172 vgoneall(sp->s_ttyvp); 173 } 174 if (sp->s_ttyvp) 175 vrele(sp->s_ttyvp); 176 sp->s_ttyvp = NULL; 177 /* 178 * s_ttyp is not zero'd; we use this to indicate 179 * that the session once had a controlling terminal. 180 * (for logging and informational purposes) 181 */ 182 } 183 sp->s_leader = NULL; 184 } 185 fixjobc(p, p->p_pgrp, 0); 186 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 187 (void)acct_process(p); 188#ifdef KTRACE 189 /* 190 * release trace file 191 */ 192 p->p_traceflag = 0; /* don't trace the vrele() */ 193 if (p->p_tracep) 194 vrele(p->p_tracep); 195#endif 196 /* 197 * Remove proc from allproc queue and pidhash chain. 198 * Place onto zombproc. Unlink from parent's child list. 199 */ 200 if ((*p->p_prev = p->p_next)) 201 p->p_next->p_prev = p->p_prev; 202 if ((p->p_next = zombproc)) 203 p->p_next->p_prev = &p->p_next; 204 p->p_prev = &zombproc; 205 zombproc = p; 206 p->p_stat = SZOMB; 207 208 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 209 if (*pp == p) { 210 *pp = p->p_hash; 211 goto done; 212 } 213 panic("exit"); 214done: 215 216 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 217 wakeup((caddr_t) initproc); 218 for (q = p->p_cptr; q != NULL; q = nq) { 219 nq = q->p_osptr; 220 if (nq != NULL) 221 nq->p_ysptr = NULL; 222 if (initproc->p_cptr) 223 initproc->p_cptr->p_ysptr = q; 224 q->p_osptr = initproc->p_cptr; 225 q->p_ysptr = NULL; 226 initproc->p_cptr = q; 227 228 q->p_pptr = initproc; 229 /* 230 * Traced processes are killed 231 * since their existence means someone is screwing up. 232 */ 233 if (q->p_flag & P_TRACED) { 234 q->p_flag &= ~P_TRACED; 235 psignal(q, SIGKILL); 236 } 237 } 238 p->p_cptr = NULL; 239 240 /* 241 * Save exit status and final rusage info, adding in child rusage 242 * info and self times. 243 */ 244 p->p_xstat = rv; 245 *p->p_ru = p->p_stats->p_ru; 246 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 247 ruadd(p->p_ru, &p->p_stats->p_cru); 248 249 /* 250 * Notify parent that we're gone. 251 */ 252 psignal(p->p_pptr, SIGCHLD); 253 wakeup((caddr_t)p->p_pptr); 254#if defined(tahoe) 255 /* move this to cpu_exit */ 256 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 257#endif 258 /* 259 * Clear curproc after we've done all operations 260 * that could block, and before tearing down the rest 261 * of the process state that might be used from clock, etc. 262 * Also, can't clear curproc while we're still runnable, 263 * as we're not on a run queue (we are current, just not 264 * a proper proc any longer!). 265 * 266 * Other substructures are freed from wait(). 267 */ 268 curproc = NULL; 269 if (--p->p_limit->p_refcnt == 0) { 270 FREE(p->p_limit, M_SUBPROC); 271 p->p_limit = NULL; 272 } 273 274 /* 275 * Finally, call machine-dependent code to release the remaining 276 * resources including address space, the kernel stack and pcb. 277 * The address space is released by "vmspace_free(p->p_vmspace)"; 278 * This is machine-dependent, as we may have to change stacks 279 * or ensure that the current one isn't reallocated before we 280 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 281 * our execution (pun intended). 282 */ 283 cpu_exit(p); 284} 285 286#if defined(COMPAT_43) 287#if defined(hp300) || defined(luna68k) 288#include <machine/frame.h> 289#define GETPS(rp) ((struct frame *)(rp))->f_sr 290#else 291#define GETPS(rp) (rp)[PS] 292#endif 293 294int 295owait(p, uap, retval) 296 struct proc *p; 297 register struct owait_args /* { 298 int dummy; 299 } */ *uap; 300 int *retval; 301{ 302 struct wait_args w; 303 304#ifdef PSL_ALLCC 305 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 306 w.options = 0; 307 w.rusage = NULL; 308 } else { 309 w.options = p->p_md.md_regs[R0]; 310 w.rusage = (struct rusage *)p->p_md.md_regs[R1]; 311 } 312#else 313 w.options = 0; 314 w.rusage = NULL; 315#endif 316 w.pid = WAIT_ANY; 317 w.status = NULL; 318 return (wait1(p, &w, retval, 1)); 319} 320#endif /* defined(COMPAT_43) */ 321 322int 323wait4(p, uap, retval) 324 struct proc *p; 325 struct wait_args *uap; 326 int *retval; 327{ 328 329 return (wait1(p, uap, retval, 0)); 330} 331 332static int 333wait1(q, uap, retval, compat) 334 register struct proc *q; 335 register struct wait_args /* { 336 int pid; 337 int *status; 338 int options; 339 struct rusage *rusage; 340 } */ *uap; 341 int retval[]; 342 int compat; 343{ 344 register int nfound; 345 register struct proc *p, *t; 346 int status, error; 347 348 if (uap->pid == 0) 349 uap->pid = -q->p_pgid; 350#ifdef notyet 351 if (uap->options &~ (WUNTRACED|WNOHANG)) 352 return (EINVAL); 353#endif 354loop: 355 nfound = 0; 356 for (p = q->p_cptr; p; p = p->p_osptr) { 357 if (uap->pid != WAIT_ANY && 358 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 359 continue; 360 nfound++; 361 if (p->p_stat == SZOMB) { 362 /* charge childs scheduling cpu usage to parent */ 363 if (curproc->p_pid != 1) { 364 curproc->p_estcpu = min(curproc->p_estcpu + 365 p->p_estcpu, UCHAR_MAX); 366 } 367 368 retval[0] = p->p_pid; 369#if defined(COMPAT_43) 370 if (compat) 371 retval[1] = p->p_xstat; 372 else 373#endif 374 if (uap->status) { 375 status = p->p_xstat; /* convert to int */ 376 if ((error = copyout((caddr_t)&status, 377 (caddr_t)uap->status, sizeof(status)))) 378 return (error); 379 } 380 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 381 (caddr_t)uap->rusage, sizeof (struct rusage)))) 382 return (error); 383 /* 384 * If we got the child via a ptrace 'attach', 385 * we need to give it back to the old parent. 386 */ 387 if (p->p_oppid && (t = pfind(p->p_oppid))) { 388 p->p_oppid = 0; 389 proc_reparent(p, t); 390 psignal(t, SIGCHLD); 391 wakeup((caddr_t)t); 392 return (0); 393 } 394 p->p_xstat = 0; 395 ruadd(&q->p_stats->p_cru, p->p_ru); 396 FREE(p->p_ru, M_ZOMBIE); 397 p->p_ru = NULL; 398 399 /* 400 * Decrement the count of procs running with this uid. 401 */ 402 (void)chgproccnt(p->p_cred->p_ruid, -1); 403 404 /* 405 * Free up credentials. 406 */ 407 if (--p->p_cred->p_refcnt == 0) { 408 crfree(p->p_cred->pc_ucred); 409 FREE(p->p_cred, M_SUBPROC); 410 p->p_cred = NULL; 411 } 412 413 /* 414 * Release reference to text vnode 415 */ 416 if (p->p_textvp) 417 vrele(p->p_textvp); 418 419 /* 420 * Finally finished with old proc entry. 421 * Unlink it from its process group and free it. 422 */ 423 leavepgrp(p); 424 if ((*p->p_prev = p->p_next)) /* off zombproc */ 425 p->p_next->p_prev = p->p_prev; 426 if ((q = p->p_ysptr)) 427 q->p_osptr = p->p_osptr; 428 if ((q = p->p_osptr)) 429 q->p_ysptr = p->p_ysptr; 430 if ((q = p->p_pptr)->p_cptr == p) 431 q->p_cptr = p->p_osptr; 432 433 /* 434 * Give machine-dependent layer a chance 435 * to free anything that cpu_exit couldn't 436 * release while still running in process context. 437 */ 438 cpu_wait(p); 439 FREE(p, M_PROC); 440 nprocs--; 441 return (0); 442 } 443 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 444 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 445 p->p_flag |= P_WAITED; 446 retval[0] = p->p_pid; 447#if defined(COMPAT_43) 448 if (compat) { 449 retval[1] = W_STOPCODE(p->p_xstat); 450 error = 0; 451 } else 452#endif 453 if (uap->status) { 454 status = W_STOPCODE(p->p_xstat); 455 error = copyout((caddr_t)&status, 456 (caddr_t)uap->status, sizeof(status)); 457 } else 458 error = 0; 459 return (error); 460 } 461 } 462 if (nfound == 0) 463 return (ECHILD); 464 if (uap->options & WNOHANG) { 465 retval[0] = 0; 466 return (0); 467 } 468 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 469 return (error); 470 goto loop; 471} 472 473/* 474 * make process 'parent' the new parent of process 'child'. 475 */ 476void 477proc_reparent(child, parent) 478 register struct proc *child; 479 register struct proc *parent; 480{ 481 register struct proc *o; 482 register struct proc *y; 483 484 if (child->p_pptr == parent) 485 return; 486 487 /* fix up the child linkage for the old parent */ 488 o = child->p_osptr; 489 y = child->p_ysptr; 490 if (y) 491 y->p_osptr = o; 492 if (o) 493 o->p_ysptr = y; 494 if (child->p_pptr->p_cptr == child) 495 child->p_pptr->p_cptr = o; 496 497 /* fix up child linkage for new parent */ 498 o = parent->p_cptr; 499 if (o) 500 o->p_ysptr = child; 501 child->p_osptr = o; 502 child->p_ysptr = NULL; 503 parent->p_cptr = child; 504 child->p_pptr = parent; 505} 506