kern_exit.c revision 5260
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 1.12 1994/10/27 05:21:39 phk Exp $ 40 */ 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/sysent.h> 45#include <sys/ioctl.h> 46#include <sys/proc.h> 47#include <sys/tty.h> 48#include <sys/time.h> 49#include <sys/resource.h> 50#include <sys/kernel.h> 51#include <sys/buf.h> 52#include <sys/wait.h> 53#include <sys/file.h> 54#include <sys/vnode.h> 55#include <sys/syslog.h> 56#include <sys/malloc.h> 57#include <sys/resourcevar.h> 58#include <sys/signalvar.h> 59#include <sys/ptrace.h> 60#include <sys/shm.h> 61#include <sys/filedesc.h> 62 63#include <machine/cpu.h> 64#ifdef COMPAT_43 65#include <machine/reg.h> 66#include <machine/psl.h> 67#endif 68 69#include <vm/vm.h> 70#include <vm/vm_kern.h> 71 72/* 73 * exit -- 74 * Death of process. 75 */ 76struct rexit_args { 77 int rval; 78}; 79__dead void 80exit(p, uap, retval) 81 struct proc *p; 82 struct rexit_args *uap; 83 int *retval; 84{ 85 86 exit1(p, W_EXITCODE(uap->rval, 0)); 87 /* NOTREACHED */ 88 while (1); 89} 90 91/* 92 * Exit: deallocate address space and other resources, change proc state 93 * to zombie, and unlink proc from allproc and parent's lists. Save exit 94 * status and rusage for wait(). Check for child processes and orphan them. 95 */ 96__dead void 97exit1(p, rv) 98 register struct proc *p; 99 int rv; 100{ 101 register struct proc *q, *nq; 102 register struct proc **pp; 103 register struct vmspace *vm; 104 105 if (p->p_pid == 1) { 106 printf("init died (signal %d, exit %d)\n", 107 WTERMSIG(rv), WEXITSTATUS(rv)); 108 panic("Going nowhere without my init!"); 109 } 110#ifdef PGINPROF 111 vmsizmon(); 112#endif 113 if (p->p_flag & P_PROFIL) 114 stopprofclock(p); 115 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 116 M_ZOMBIE, M_WAITOK); 117 /* 118 * If parent is waiting for us to exit or exec, 119 * P_PPWAIT is set; we will wakeup the parent below. 120 */ 121 p->p_flag &= ~(P_TRACED | P_PPWAIT); 122 p->p_flag |= P_WEXIT; 123 p->p_sigignore = ~0; 124 p->p_siglist = 0; 125 untimeout(realitexpire, (caddr_t)p); 126 127 /* 128 * Close open files and release open-file table. 129 * This may block! 130 */ 131 fdfree(p); 132 133 /* The next two chunks should probably be moved to vmspace_exit. */ 134 vm = p->p_vmspace; 135#ifdef SYSVSHM 136 if (vm->vm_shm) 137 shmexit(p); 138#endif 139 /* 140 * Release user portion of address space. 141 * This releases references to vnodes, 142 * which could cause I/O if the file has been unlinked. 143 * Need to do this early enough that we can still sleep. 144 * Can't free the entire vmspace as the kernel stack 145 * may be mapped within that space also. 146 */ 147 if (vm->vm_refcnt == 1) 148 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 149 VM_MAXUSER_ADDRESS); 150 151 if (SESS_LEADER(p)) { 152 register struct session *sp = p->p_session; 153 154 if (sp->s_ttyvp) { 155 /* 156 * Controlling process. 157 * Signal foreground pgrp, 158 * drain controlling terminal 159 * and revoke access to controlling terminal. 160 */ 161 if (sp->s_ttyp->t_session == sp) { 162 if (sp->s_ttyp->t_pgrp) 163 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 164 (void) ttywait(sp->s_ttyp); 165 /* 166 * The tty could have been revoked 167 * if we blocked. 168 */ 169 if (sp->s_ttyvp) 170 vgoneall(sp->s_ttyvp); 171 } 172 if (sp->s_ttyvp) 173 vrele(sp->s_ttyvp); 174 sp->s_ttyvp = NULL; 175 /* 176 * s_ttyp is not zero'd; we use this to indicate 177 * that the session once had a controlling terminal. 178 * (for logging and informational purposes) 179 */ 180 } 181 sp->s_leader = NULL; 182 } 183 fixjobc(p, p->p_pgrp, 0); 184 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 185 (void)acct_process(p); 186#ifdef KTRACE 187 /* 188 * release trace file 189 */ 190 p->p_traceflag = 0; /* don't trace the vrele() */ 191 if (p->p_tracep) 192 vrele(p->p_tracep); 193#endif 194 /* 195 * Remove proc from allproc queue and pidhash chain. 196 * Place onto zombproc. Unlink from parent's child list. 197 */ 198 if ((*p->p_prev = p->p_next)) 199 p->p_next->p_prev = p->p_prev; 200 if ((p->p_next = zombproc)) 201 p->p_next->p_prev = &p->p_next; 202 p->p_prev = &zombproc; 203 zombproc = p; 204 p->p_stat = SZOMB; 205 206 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 207 if (*pp == p) { 208 *pp = p->p_hash; 209 goto done; 210 } 211 panic("exit"); 212done: 213 214 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 215 wakeup((caddr_t) initproc); 216 for (q = p->p_cptr; q != NULL; q = nq) { 217 nq = q->p_osptr; 218 if (nq != NULL) 219 nq->p_ysptr = NULL; 220 if (initproc->p_cptr) 221 initproc->p_cptr->p_ysptr = q; 222 q->p_osptr = initproc->p_cptr; 223 q->p_ysptr = NULL; 224 initproc->p_cptr = q; 225 226 q->p_pptr = initproc; 227 /* 228 * Traced processes are killed 229 * since their existence means someone is screwing up. 230 */ 231 if (q->p_flag & P_TRACED) { 232 q->p_flag &= ~P_TRACED; 233 psignal(q, SIGKILL); 234 } 235 } 236 p->p_cptr = NULL; 237 238 /* 239 * Save exit status and final rusage info, adding in child rusage 240 * info and self times. 241 */ 242 p->p_xstat = rv; 243 *p->p_ru = p->p_stats->p_ru; 244 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 245 ruadd(p->p_ru, &p->p_stats->p_cru); 246 247 /* 248 * Notify parent that we're gone. 249 */ 250 psignal(p->p_pptr, SIGCHLD); 251 wakeup((caddr_t)p->p_pptr); 252#if defined(tahoe) 253 /* move this to cpu_exit */ 254 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 255#endif 256 /* 257 * Clear curproc after we've done all operations 258 * that could block, and before tearing down the rest 259 * of the process state that might be used from clock, etc. 260 * Also, can't clear curproc while we're still runnable, 261 * as we're not on a run queue (we are current, just not 262 * a proper proc any longer!). 263 * 264 * Other substructures are freed from wait(). 265 */ 266 curproc = NULL; 267 if (--p->p_limit->p_refcnt == 0) { 268 FREE(p->p_limit, M_SUBPROC); 269 p->p_limit = NULL; 270 } 271 272 /* 273 * Finally, call machine-dependent code to release the remaining 274 * resources including address space, the kernel stack and pcb. 275 * The address space is released by "vmspace_free(p->p_vmspace)"; 276 * This is machine-dependent, as we may have to change stacks 277 * or ensure that the current one isn't reallocated before we 278 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 279 * our execution (pun intended). 280 */ 281 cpu_exit(p); 282} 283 284struct wait_args { 285 int pid; 286 int *status; 287 int options; 288 struct rusage *rusage; 289#if defined(COMPAT_43) || defined(COMPAT_IBCS2) 290 int compat; /* pseudo */ 291#endif 292}; 293 294#if defined(COMPAT_43) || defined(COMPAT_IBCS2) 295#if defined(hp300) || defined(luna68k) 296#include <machine/frame.h> 297#define GETPS(rp) ((struct frame *)(rp))->f_sr 298#else 299#define GETPS(rp) (rp)[PS] 300#endif 301 302int 303owait(p, uap, retval) 304 struct proc *p; 305 register struct wait_args *uap; 306 int *retval; 307{ 308 309#ifdef PSL_ALLCC 310 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 311 uap->options = 0; 312 uap->rusage = NULL; 313 } else { 314 uap->options = p->p_md.md_regs[R0]; 315 uap->rusage = (struct rusage *)p->p_md.md_regs[R1]; 316 } 317#else 318 uap->options = 0; 319 uap->rusage = NULL; 320#endif 321 uap->pid = WAIT_ANY; 322 uap->status = NULL; 323 uap->compat = 1; 324 return (wait1(p, uap, retval)); 325} 326 327int 328wait4(p, uap, retval) 329 struct proc *p; 330 struct wait_args *uap; 331 int *retval; 332{ 333 334 uap->compat = 0; 335 return (wait1(p, uap, retval)); 336} 337#else 338#define wait1 wait4 339#endif 340 341int 342wait1(q, uap, retval) 343 register struct proc *q; 344 register struct wait_args *uap; 345 int retval[]; 346{ 347 register int nfound; 348 register struct proc *p, *t; 349 int status, error, sig; 350 351 if (uap->pid == 0) 352 uap->pid = -q->p_pgid; 353#ifdef notyet 354 if (uap->options &~ (WUNTRACED|WNOHANG)) 355 return (EINVAL); 356#endif 357loop: 358 nfound = 0; 359 for (p = q->p_cptr; p; p = p->p_osptr) { 360 if (uap->pid != WAIT_ANY && 361 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 362 continue; 363 nfound++; 364#if defined(COMPAT_43) || defined(COMPAT_IBCS2) 365 if (q->p_sysent->sv_sigtbl) { 366 if ((p->p_xstat & 0xff) < q->p_sysent->sv_sigsize) 367 sig = q->p_sysent->sv_sigtbl[p->p_xstat & 0xff]; 368 else 369 sig = q->p_sysent->sv_sigsize + 1; 370 } else 371 sig = p->p_xstat; 372#endif 373 if (p->p_stat == SZOMB) { 374 /* charge childs scheduling cpu usage to parent */ 375 if (curproc->p_pid != 1) { 376 curproc->p_estcpu = min(curproc->p_estcpu + 377 p->p_estcpu, UCHAR_MAX); 378 } 379 380 retval[0] = p->p_pid; 381#if defined(COMPAT_43) || defined(COMPAT_IBCS2) 382 if (uap->compat) 383 retval[1] = sig; 384 else 385#endif 386 if (uap->status) { 387 status = p->p_xstat; /* convert to int */ 388 if ((error = copyout((caddr_t)&status, 389 (caddr_t)uap->status, sizeof(status)))) 390 return (error); 391 } 392 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 393 (caddr_t)uap->rusage, sizeof (struct rusage)))) 394 return (error); 395 /* 396 * If we got the child via a ptrace 'attach', 397 * we need to give it back to the old parent. 398 */ 399 if (p->p_oppid && (t = pfind(p->p_oppid))) { 400 p->p_oppid = 0; 401 proc_reparent(p, t); 402 psignal(t, SIGCHLD); 403 wakeup((caddr_t)t); 404 return (0); 405 } 406 p->p_xstat = 0; 407 ruadd(&q->p_stats->p_cru, p->p_ru); 408 FREE(p->p_ru, M_ZOMBIE); 409 p->p_ru = NULL; 410 411 /* 412 * Decrement the count of procs running with this uid. 413 */ 414 (void)chgproccnt(p->p_cred->p_ruid, -1); 415 416 /* 417 * Free up credentials. 418 */ 419 if (--p->p_cred->p_refcnt == 0) { 420 crfree(p->p_cred->pc_ucred); 421 FREE(p->p_cred, M_SUBPROC); 422 p->p_cred = NULL; 423 } 424 425 /* 426 * Release reference to text vnode 427 */ 428 if (p->p_textvp) 429 vrele(p->p_textvp); 430 431 /* 432 * Finally finished with old proc entry. 433 * Unlink it from its process group and free it. 434 */ 435 leavepgrp(p); 436 if ((*p->p_prev = p->p_next)) /* off zombproc */ 437 p->p_next->p_prev = p->p_prev; 438 if ((q = p->p_ysptr)) 439 q->p_osptr = p->p_osptr; 440 if ((q = p->p_osptr)) 441 q->p_ysptr = p->p_ysptr; 442 if ((q = p->p_pptr)->p_cptr == p) 443 q->p_cptr = p->p_osptr; 444 445 /* 446 * Give machine-dependent layer a chance 447 * to free anything that cpu_exit couldn't 448 * release while still running in process context. 449 */ 450 cpu_wait(p); 451 FREE(p, M_PROC); 452 nprocs--; 453 return (0); 454 } 455 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 456 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 457 p->p_flag |= P_WAITED; 458 retval[0] = p->p_pid; 459#if defined(COMPAT_43) || defined(COMPAT_IBCS2) 460 if (uap->compat) { 461 retval[1] = W_STOPCODE(sig); 462 error = 0; 463 } else 464#endif 465 if (uap->status) { 466 status = W_STOPCODE(p->p_xstat); 467 error = copyout((caddr_t)&status, 468 (caddr_t)uap->status, sizeof(status)); 469 } else 470 error = 0; 471 return (error); 472 } 473 } 474 if (nfound == 0) 475 return (ECHILD); 476 if (uap->options & WNOHANG) { 477 retval[0] = 0; 478 return (0); 479 } 480 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 481 return (error); 482 goto loop; 483} 484 485/* 486 * make process 'parent' the new parent of process 'child'. 487 */ 488void 489proc_reparent(child, parent) 490 register struct proc *child; 491 register struct proc *parent; 492{ 493 register struct proc *o; 494 register struct proc *y; 495 496 if (child->p_pptr == parent) 497 return; 498 499 /* fix up the child linkage for the old parent */ 500 o = child->p_osptr; 501 y = child->p_ysptr; 502 if (y) 503 y->p_osptr = o; 504 if (o) 505 o->p_ysptr = y; 506 if (child->p_pptr->p_cptr == child) 507 child->p_pptr->p_cptr = o; 508 509 /* fix up child linkage for new parent */ 510 o = parent->p_cptr; 511 if (o) 512 o->p_ysptr = child; 513 child->p_osptr = o; 514 child->p_ysptr = NULL; 515 parent->p_cptr = child; 516 child->p_pptr = parent; 517} 518