kern_exit.c revision 13150
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 1.22 1995/12/27 15:24:15 joerg 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/filedesc.h> 62 63#ifdef SYSVSHM 64#include <sys/shm.h> 65#endif 66#ifdef SYSVSEM 67#include <sys/sem.h> 68#endif 69 70#include <machine/cpu.h> 71#ifdef COMPAT_43 72#include <machine/reg.h> 73#include <machine/psl.h> 74#endif 75 76#include <vm/vm.h> 77#include <vm/vm_param.h> 78#include <vm/vm_prot.h> 79#include <vm/lock.h> 80#include <vm/pmap.h> 81#include <vm/vm_map.h> 82#include <vm/vm_kern.h> 83 84static int wait1 __P((struct proc *, struct wait_args *, int [], int)); 85 86/* 87 * exit -- 88 * Death of process. 89 */ 90__dead void 91exit(p, uap, retval) 92 struct proc *p; 93 struct rexit_args /* { 94 int rval; 95 } */ *uap; 96 int *retval; 97{ 98 99 exit1(p, W_EXITCODE(uap->rval, 0)); 100 /* NOTREACHED */ 101} 102 103/* 104 * Exit: deallocate address space and other resources, change proc state 105 * to zombie, and unlink proc from allproc and parent's lists. Save exit 106 * status and rusage for wait(). Check for child processes and orphan them. 107 */ 108__dead void 109exit1(p, rv) 110 register struct proc *p; 111 int rv; 112{ 113 register struct proc *q, *nq; 114 register struct proc **pp; 115 register struct vmspace *vm; 116 117 if (p->p_pid == 1) { 118 printf("init died (signal %d, exit %d)\n", 119 WTERMSIG(rv), WEXITSTATUS(rv)); 120 panic("Going nowhere without my init!"); 121 } 122#ifdef PGINPROF 123 vmsizmon(); 124#endif 125 if (p->p_flag & P_PROFIL) 126 stopprofclock(p); 127 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 128 M_ZOMBIE, M_WAITOK); 129 /* 130 * If parent is waiting for us to exit or exec, 131 * P_PPWAIT is set; we will wakeup the parent below. 132 */ 133 p->p_flag &= ~(P_TRACED | P_PPWAIT); 134 p->p_flag |= P_WEXIT; 135 p->p_sigignore = ~0; 136 p->p_siglist = 0; 137 untimeout(realitexpire, (caddr_t)p); 138 139 /* 140 * Close open files and release open-file table. 141 * This may block! 142 */ 143 fdfree(p); 144 145#ifdef SYSVSEM 146 semexit(p); 147#endif 148 149 /* The next two chunks should probably be moved to vmspace_exit. */ 150 vm = p->p_vmspace; 151#ifdef SYSVSHM 152 if (vm->vm_shm) 153 shmexit(p); 154#endif 155 /* 156 * Release user portion of address space. 157 * This releases references to vnodes, 158 * which could cause I/O if the file has been unlinked. 159 * Need to do this early enough that we can still sleep. 160 * Can't free the entire vmspace as the kernel stack 161 * may be mapped within that space also. 162 */ 163 if (vm->vm_refcnt == 1) 164 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 165 VM_MAXUSER_ADDRESS); 166 167 if (SESS_LEADER(p)) { 168 register struct session *sp = p->p_session; 169 170 if (sp->s_ttyvp) { 171 /* 172 * Controlling process. 173 * Signal foreground pgrp, 174 * drain controlling terminal 175 * and revoke access to controlling terminal. 176 */ 177 if (sp->s_ttyp->t_session == sp) { 178 if (sp->s_ttyp->t_pgrp) 179 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 180 (void) ttywait(sp->s_ttyp); 181 /* 182 * The tty could have been revoked 183 * if we blocked. 184 */ 185 if (sp->s_ttyvp) 186 vgoneall(sp->s_ttyvp); 187 } 188 if (sp->s_ttyvp) 189 vrele(sp->s_ttyvp); 190 sp->s_ttyvp = NULL; 191 /* 192 * s_ttyp is not zero'd; we use this to indicate 193 * that the session once had a controlling terminal. 194 * (for logging and informational purposes) 195 */ 196 } 197 sp->s_leader = NULL; 198 } 199 fixjobc(p, p->p_pgrp, 0); 200 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 201 (void)acct_process(p); 202#ifdef KTRACE 203 /* 204 * release trace file 205 */ 206 p->p_traceflag = 0; /* don't trace the vrele() */ 207 if (p->p_tracep) 208 vrele(p->p_tracep); 209#endif 210 /* 211 * Remove proc from allproc queue and pidhash chain. 212 * Place onto zombproc. Unlink from parent's child list. 213 */ 214 if ((*p->p_prev = p->p_next)) 215 p->p_next->p_prev = p->p_prev; 216 if ((p->p_next = zombproc)) 217 p->p_next->p_prev = &p->p_next; 218 p->p_prev = &zombproc; 219 zombproc = p; 220 p->p_stat = SZOMB; 221 222 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 223 if (*pp == p) { 224 *pp = p->p_hash; 225 goto done; 226 } 227 panic("exit"); 228done: 229 230 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 231 wakeup((caddr_t) initproc); 232 for (q = p->p_cptr; q != NULL; q = nq) { 233 nq = q->p_osptr; 234 if (nq != NULL) 235 nq->p_ysptr = NULL; 236 if (initproc->p_cptr) 237 initproc->p_cptr->p_ysptr = q; 238 q->p_osptr = initproc->p_cptr; 239 q->p_ysptr = NULL; 240 initproc->p_cptr = q; 241 242 q->p_pptr = initproc; 243 /* 244 * Traced processes are killed 245 * since their existence means someone is screwing up. 246 */ 247 if (q->p_flag & P_TRACED) { 248 q->p_flag &= ~P_TRACED; 249 psignal(q, SIGKILL); 250 } 251 } 252 p->p_cptr = NULL; 253 254 /* 255 * Save exit status and final rusage info, adding in child rusage 256 * info and self times. 257 */ 258 p->p_xstat = rv; 259 *p->p_ru = p->p_stats->p_ru; 260 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 261 ruadd(p->p_ru, &p->p_stats->p_cru); 262 263 /* 264 * Notify parent that we're gone. 265 */ 266 psignal(p->p_pptr, SIGCHLD); 267 wakeup((caddr_t)p->p_pptr); 268#if defined(tahoe) 269 /* move this to cpu_exit */ 270 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 271#endif 272 /* 273 * Clear curproc after we've done all operations 274 * that could block, and before tearing down the rest 275 * of the process state that might be used from clock, etc. 276 * Also, can't clear curproc while we're still runnable, 277 * as we're not on a run queue (we are current, just not 278 * a proper proc any longer!). 279 * 280 * Other substructures are freed from wait(). 281 */ 282 curproc = NULL; 283 if (--p->p_limit->p_refcnt == 0) { 284 FREE(p->p_limit, M_SUBPROC); 285 p->p_limit = NULL; 286 } 287 288 /* 289 * Finally, call machine-dependent code to release the remaining 290 * resources including address space, the kernel stack and pcb. 291 * The address space is released by "vmspace_free(p->p_vmspace)"; 292 * This is machine-dependent, as we may have to change stacks 293 * or ensure that the current one isn't reallocated before we 294 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 295 * our execution (pun intended). 296 */ 297 cpu_exit(p); 298} 299 300#ifdef COMPAT_43 301#if defined(hp300) || defined(luna68k) 302#include <machine/frame.h> 303#define GETPS(rp) ((struct frame *)(rp))->f_sr 304#else 305#define GETPS(rp) (rp)[PS] 306#endif 307 308int 309owait(p, uap, retval) 310 struct proc *p; 311 register struct owait_args /* { 312 int dummy; 313 } */ *uap; 314 int *retval; 315{ 316 struct wait_args w; 317 318#ifdef PSL_ALLCC 319 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 320 w.options = 0; 321 w.rusage = NULL; 322 } else { 323 w.options = p->p_md.md_regs[R0]; 324 w.rusage = (struct rusage *)p->p_md.md_regs[R1]; 325 } 326#else 327 w.options = 0; 328 w.rusage = NULL; 329#endif 330 w.pid = WAIT_ANY; 331 w.status = NULL; 332 return (wait1(p, &w, retval, 1)); 333} 334#endif /* COMPAT_43 */ 335 336int 337wait4(p, uap, retval) 338 struct proc *p; 339 struct wait_args *uap; 340 int *retval; 341{ 342 343 return (wait1(p, uap, retval, 0)); 344} 345 346static int 347wait1(q, uap, retval, compat) 348 register struct proc *q; 349 register struct wait_args /* { 350 int pid; 351 int *status; 352 int options; 353 struct rusage *rusage; 354 } */ *uap; 355 int retval[]; 356 int compat; 357{ 358 register int nfound; 359 register struct proc *p, *t; 360 int status, error; 361 362 if (uap->pid == 0) 363 uap->pid = -q->p_pgid; 364#ifdef notyet 365 if (uap->options &~ (WUNTRACED|WNOHANG)) 366 return (EINVAL); 367#endif 368loop: 369 nfound = 0; 370 for (p = q->p_cptr; p; p = p->p_osptr) { 371 if (uap->pid != WAIT_ANY && 372 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 373 continue; 374 nfound++; 375 if (p->p_stat == SZOMB) { 376 /* charge childs scheduling cpu usage to parent */ 377 if (curproc->p_pid != 1) { 378 curproc->p_estcpu = min(curproc->p_estcpu + 379 p->p_estcpu, UCHAR_MAX); 380 } 381 382 retval[0] = p->p_pid; 383#ifdef COMPAT_43 384 if (compat) 385 retval[1] = p->p_xstat; 386 else 387#endif 388 if (uap->status) { 389 status = p->p_xstat; /* convert to int */ 390 if ((error = copyout((caddr_t)&status, 391 (caddr_t)uap->status, sizeof(status)))) 392 return (error); 393 } 394 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 395 (caddr_t)uap->rusage, sizeof (struct rusage)))) 396 return (error); 397 /* 398 * If we got the child via a ptrace 'attach', 399 * we need to give it back to the old parent. 400 */ 401 if (p->p_oppid && (t = pfind(p->p_oppid))) { 402 p->p_oppid = 0; 403 proc_reparent(p, t); 404 psignal(t, SIGCHLD); 405 wakeup((caddr_t)t); 406 return (0); 407 } 408 p->p_xstat = 0; 409 ruadd(&q->p_stats->p_cru, p->p_ru); 410 FREE(p->p_ru, M_ZOMBIE); 411 p->p_ru = NULL; 412 413 /* 414 * Decrement the count of procs running with this uid. 415 */ 416 (void)chgproccnt(p->p_cred->p_ruid, -1); 417 418 /* 419 * Free up credentials. 420 */ 421 if (--p->p_cred->p_refcnt == 0) { 422 crfree(p->p_cred->pc_ucred); 423 FREE(p->p_cred, M_SUBPROC); 424 p->p_cred = NULL; 425 } 426 427 /* 428 * Release reference to text vnode 429 */ 430 if (p->p_textvp) 431 vrele(p->p_textvp); 432 433 /* 434 * Finally finished with old proc entry. 435 * Unlink it from its process group and free it. 436 */ 437 leavepgrp(p); 438 if ((*p->p_prev = p->p_next)) /* off zombproc */ 439 p->p_next->p_prev = p->p_prev; 440 if ((q = p->p_ysptr)) 441 q->p_osptr = p->p_osptr; 442 if ((q = p->p_osptr)) 443 q->p_ysptr = p->p_ysptr; 444 if ((q = p->p_pptr)->p_cptr == p) 445 q->p_cptr = p->p_osptr; 446 447 /* 448 * Give machine-dependent layer a chance 449 * to free anything that cpu_exit couldn't 450 * release while still running in process context. 451 */ 452 cpu_wait(p); 453 FREE(p, M_PROC); 454 nprocs--; 455 return (0); 456 } 457 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 458 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 459 p->p_flag |= P_WAITED; 460 retval[0] = p->p_pid; 461#ifdef COMPAT_43 462 if (compat) { 463 retval[1] = W_STOPCODE(p->p_xstat); 464 error = 0; 465 } else 466#endif 467 if (uap->status) { 468 status = W_STOPCODE(p->p_xstat); 469 error = copyout((caddr_t)&status, 470 (caddr_t)uap->status, sizeof(status)); 471 } else 472 error = 0; 473 return (error); 474 } 475 } 476 if (nfound == 0) 477 return (ECHILD); 478 if (uap->options & WNOHANG) { 479 retval[0] = 0; 480 return (0); 481 } 482 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 483 return (error); 484 goto loop; 485} 486 487/* 488 * make process 'parent' the new parent of process 'child'. 489 */ 490void 491proc_reparent(child, parent) 492 register struct proc *child; 493 register struct proc *parent; 494{ 495 register struct proc *o; 496 register struct proc *y; 497 498 if (child->p_pptr == parent) 499 return; 500 501 /* fix up the child linkage for the old parent */ 502 o = child->p_osptr; 503 y = child->p_ysptr; 504 if (y) 505 y->p_osptr = o; 506 if (o) 507 o->p_ysptr = y; 508 if (child->p_pptr->p_cptr == child) 509 child->p_pptr->p_cptr = o; 510 511 /* fix up child linkage for new parent */ 512 o = parent->p_cptr; 513 if (o) 514 o->p_ysptr = child; 515 child->p_osptr = o; 516 child->p_ysptr = NULL; 517 parent->p_cptr = child; 518 child->p_pptr = parent; 519} 520