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 1.27 1996/01/19 03:58:03 dyson Exp $ 40 */ 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/sysent.h> 48 #include <sys/ioctl.h> 49 #include <sys/proc.h> 50 #include <sys/tty.h> 51 #include <sys/time.h> 52 #include <sys/resource.h> 53 #include <sys/kernel.h> 54 #include <sys/buf.h> 55 #include <sys/wait.h> 56 #include <sys/file.h> 57 #include <sys/vnode.h> 58 #include <sys/syslog.h> 59 #include <sys/malloc.h> 60 #include <sys/resourcevar.h> 61 #include <sys/signalvar.h> 62 #include <sys/ptrace.h> 63 #include <sys/filedesc.h> 64 #include <sys/shm.h> 65 #include <sys/sem.h> 66 67 #include <machine/cpu.h> 68 #ifdef COMPAT_43 69 #include <machine/reg.h> 70 #include <machine/psl.h> 71 #endif 72 73 #include <vm/vm.h> 74 #include <vm/vm_param.h> 75 #include <vm/vm_prot.h> 76 #include <vm/lock.h> 77 #include <vm/pmap.h> 78 #include <vm/vm_map.h> 79 #include <vm/vm_kern.h> 80 81 static int wait1 __P((struct proc *, struct wait_args *, int [], int)); 82 83 /* 84 * exit -- 85 * Death of process. 86 */ 87 __dead void 88 exit(p, uap, retval) 89 struct proc *p; 90 struct rexit_args /* { 91 int rval; 92 } */ *uap; 93 int *retval; 94 { 95 96 exit1(p, W_EXITCODE(uap->rval, 0)); 97 /* NOTREACHED */ 98 } 99 100 /* 101 * Exit: deallocate address space and other resources, change proc state 102 * to zombie, and unlink proc from allproc and parent's lists. Save exit 103 * status and rusage for wait(). Check for child processes and orphan them. 104 */ 105 __dead void 106 exit1(p, rv) 107 register struct proc *p; 108 int rv; 109 { 110 register struct proc *q, *nq; 111 register struct proc **pp; 112 register struct vmspace *vm; 113 114 if (p->p_pid == 1) { 115 printf("init died (signal %d, exit %d)\n", 116 WTERMSIG(rv), WEXITSTATUS(rv)); 117 panic("Going nowhere without my init!"); 118 } 119 #ifdef PGINPROF 120 vmsizmon(); 121 #endif 122 if (p->p_flag & P_PROFIL) 123 stopprofclock(p); 124 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 125 M_ZOMBIE, M_WAITOK); 126 /* 127 * If parent is waiting for us to exit or exec, 128 * P_PPWAIT is set; we will wakeup the parent below. 129 */ 130 p->p_flag &= ~(P_TRACED | P_PPWAIT); 131 p->p_flag |= P_WEXIT; 132 p->p_sigignore = ~0; 133 p->p_siglist = 0; 134 untimeout(realitexpire, (caddr_t)p); 135 136 /* 137 * Close open files and release open-file table. 138 * This may block! 139 */ 140 fdfree(p); 141 142 /* 143 * XXX Shutdown SYSV semaphores 144 */ 145 semexit(p); 146 147 /* The next two chunks should probably be moved to vmspace_exit. */ 148 vm = p->p_vmspace; 149 if (vm->vm_shm) 150 shmexit(p); 151 /* 152 * Release user portion of address space. 153 * This releases references to vnodes, 154 * which could cause I/O if the file has been unlinked. 155 * Need to do this early enough that we can still sleep. 156 * Can't free the entire vmspace as the kernel stack 157 * may be mapped within that space also. 158 */ 159 if (vm->vm_refcnt == 1) 160 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 161 VM_MAXUSER_ADDRESS); 162 163 if (SESS_LEADER(p)) { 164 register struct session *sp = p->p_session; 165 166 if (sp->s_ttyvp) { 167 /* 168 * Controlling process. 169 * Signal foreground pgrp, 170 * drain controlling terminal 171 * and revoke access to controlling terminal. 172 */ 173 if (sp->s_ttyp->t_session == sp) { 174 if (sp->s_ttyp->t_pgrp) 175 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 176 (void) ttywait(sp->s_ttyp); 177 /* 178 * The tty could have been revoked 179 * if we blocked. 180 */ 181 if (sp->s_ttyvp) 182 vgoneall(sp->s_ttyvp); 183 } 184 if (sp->s_ttyvp) 185 vrele(sp->s_ttyvp); 186 sp->s_ttyvp = NULL; 187 /* 188 * s_ttyp is not zero'd; we use this to indicate 189 * that the session once had a controlling terminal. 190 * (for logging and informational purposes) 191 */ 192 } 193 sp->s_leader = NULL; 194 } 195 fixjobc(p, p->p_pgrp, 0); 196 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 197 (void)acct_process(p); 198 #ifdef KTRACE 199 /* 200 * release trace file 201 */ 202 p->p_traceflag = 0; /* don't trace the vrele() */ 203 if (p->p_tracep) 204 vrele(p->p_tracep); 205 #endif 206 /* 207 * Remove proc from allproc queue and pidhash chain. 208 * Place onto zombproc. Unlink from parent's child list. 209 */ 210 if ((*p->p_prev = p->p_next)) 211 p->p_next->p_prev = p->p_prev; 212 if ((p->p_next = zombproc)) 213 p->p_next->p_prev = &p->p_next; 214 p->p_prev = &zombproc; 215 zombproc = p; 216 p->p_stat = SZOMB; 217 218 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 219 if (*pp == p) { 220 *pp = p->p_hash; 221 goto done; 222 } 223 panic("exit"); 224 done: 225 226 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 227 wakeup((caddr_t) initproc); 228 for (q = p->p_cptr; q != NULL; q = nq) { 229 nq = q->p_osptr; 230 if (nq != NULL) 231 nq->p_ysptr = NULL; 232 if (initproc->p_cptr) 233 initproc->p_cptr->p_ysptr = q; 234 q->p_osptr = initproc->p_cptr; 235 q->p_ysptr = NULL; 236 initproc->p_cptr = q; 237 238 q->p_pptr = initproc; 239 /* 240 * Traced processes are killed 241 * since their existence means someone is screwing up. 242 */ 243 if (q->p_flag & P_TRACED) { 244 q->p_flag &= ~P_TRACED; 245 psignal(q, SIGKILL); 246 } 247 } 248 p->p_cptr = NULL; 249 250 /* 251 * Save exit status and final rusage info, adding in child rusage 252 * info and self times. 253 */ 254 p->p_xstat = rv; 255 *p->p_ru = p->p_stats->p_ru; 256 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 257 ruadd(p->p_ru, &p->p_stats->p_cru); 258 259 /* 260 * Notify parent that we're gone. 261 */ 262 psignal(p->p_pptr, SIGCHLD); 263 wakeup((caddr_t)p->p_pptr); 264 #if defined(tahoe) 265 /* move this to cpu_exit */ 266 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 267 #endif 268 /* 269 * Clear curproc after we've done all operations 270 * that could block, and before tearing down the rest 271 * of the process state that might be used from clock, etc. 272 * Also, can't clear curproc while we're still runnable, 273 * as we're not on a run queue (we are current, just not 274 * a proper proc any longer!). 275 * 276 * Other substructures are freed from wait(). 277 */ 278 curproc = NULL; 279 if (--p->p_limit->p_refcnt == 0) { 280 FREE(p->p_limit, M_SUBPROC); 281 p->p_limit = NULL; 282 } 283 284 /* 285 * Finally, call machine-dependent code to release the remaining 286 * resources including address space, the kernel stack and pcb. 287 * The address space is released by "vmspace_free(p->p_vmspace)"; 288 * This is machine-dependent, as we may have to change stacks 289 * or ensure that the current one isn't reallocated before we 290 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 291 * our execution (pun intended). 292 */ 293 cpu_exit(p); 294 } 295 296 #ifdef COMPAT_43 297 #if defined(hp300) || defined(luna68k) 298 #include <machine/frame.h> 299 #define GETPS(rp) ((struct frame *)(rp))->f_sr 300 #else 301 #define GETPS(rp) (rp)[PS] 302 #endif 303 304 int 305 owait(p, uap, retval) 306 struct proc *p; 307 register struct owait_args /* { 308 int dummy; 309 } */ *uap; 310 int *retval; 311 { 312 struct wait_args w; 313 314 #ifdef PSL_ALLCC 315 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 316 w.options = 0; 317 w.rusage = NULL; 318 } else { 319 w.options = p->p_md.md_regs[R0]; 320 w.rusage = (struct rusage *)p->p_md.md_regs[R1]; 321 } 322 #else 323 w.options = 0; 324 w.rusage = NULL; 325 #endif 326 w.pid = WAIT_ANY; 327 w.status = NULL; 328 return (wait1(p, &w, retval, 1)); 329 } 330 #endif /* COMPAT_43 */ 331 332 int 333 wait4(p, uap, retval) 334 struct proc *p; 335 struct wait_args *uap; 336 int *retval; 337 { 338 339 return (wait1(p, uap, retval, 0)); 340 } 341 342 static int 343 wait1(q, uap, retval, compat) 344 register struct proc *q; 345 register struct wait_args /* { 346 int pid; 347 int *status; 348 int options; 349 struct rusage *rusage; 350 } */ *uap; 351 int retval[]; 352 int compat; 353 { 354 register int nfound; 355 register struct proc *p, *t; 356 int status, error; 357 358 if (uap->pid == 0) 359 uap->pid = -q->p_pgid; 360 #ifdef notyet 361 if (uap->options &~ (WUNTRACED|WNOHANG)) 362 return (EINVAL); 363 #endif 364 loop: 365 nfound = 0; 366 for (p = q->p_cptr; p; p = p->p_osptr) { 367 if (uap->pid != WAIT_ANY && 368 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 369 continue; 370 nfound++; 371 if (p->p_stat == SZOMB) { 372 /* charge childs scheduling cpu usage to parent */ 373 if (curproc->p_pid != 1) { 374 curproc->p_estcpu = min(curproc->p_estcpu + 375 p->p_estcpu, UCHAR_MAX); 376 } 377 378 retval[0] = p->p_pid; 379 #ifdef COMPAT_43 380 if (compat) 381 retval[1] = p->p_xstat; 382 else 383 #endif 384 if (uap->status) { 385 status = p->p_xstat; /* convert to int */ 386 if ((error = copyout((caddr_t)&status, 387 (caddr_t)uap->status, sizeof(status)))) 388 return (error); 389 } 390 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 391 (caddr_t)uap->rusage, sizeof (struct rusage)))) 392 return (error); 393 /* 394 * If we got the child via a ptrace 'attach', 395 * we need to give it back to the old parent. 396 */ 397 if (p->p_oppid && (t = pfind(p->p_oppid))) { 398 p->p_oppid = 0; 399 proc_reparent(p, t); 400 psignal(t, SIGCHLD); 401 wakeup((caddr_t)t); 402 return (0); 403 } 404 p->p_xstat = 0; 405 ruadd(&q->p_stats->p_cru, p->p_ru); 406 FREE(p->p_ru, M_ZOMBIE); 407 p->p_ru = NULL; 408 409 /* 410 * Decrement the count of procs running with this uid. 411 */ 412 (void)chgproccnt(p->p_cred->p_ruid, -1); 413 414 /* 415 * Release reference to text vnode 416 */ 417 if (p->p_textvp) 418 vrele(p->p_textvp); 419 420 /* 421 * Free up credentials. 422 */ 423 if (--p->p_cred->p_refcnt == 0) { 424 crfree(p->p_cred->pc_ucred); 425 FREE(p->p_cred, M_SUBPROC); 426 p->p_cred = NULL; 427 } 428 429 /* 430 * Finally finished with old proc entry. 431 * Unlink it from its process group and free it. 432 */ 433 leavepgrp(p); 434 if ((*p->p_prev = p->p_next)) /* off zombproc */ 435 p->p_next->p_prev = p->p_prev; 436 if ((q = p->p_ysptr)) 437 q->p_osptr = p->p_osptr; 438 if ((q = p->p_osptr)) 439 q->p_ysptr = p->p_ysptr; 440 if ((q = p->p_pptr)->p_cptr == p) 441 q->p_cptr = p->p_osptr; 442 443 /* 444 * Give machine-dependent layer a chance 445 * to free anything that cpu_exit couldn't 446 * release while still running in process context. 447 */ 448 cpu_wait(p); 449 FREE(p, M_PROC); 450 nprocs--; 451 return (0); 452 } 453 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 454 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 455 p->p_flag |= P_WAITED; 456 retval[0] = p->p_pid; 457 #ifdef COMPAT_43 458 if (compat) { 459 retval[1] = W_STOPCODE(p->p_xstat); 460 error = 0; 461 } else 462 #endif 463 if (uap->status) { 464 status = W_STOPCODE(p->p_xstat); 465 error = copyout((caddr_t)&status, 466 (caddr_t)uap->status, sizeof(status)); 467 } else 468 error = 0; 469 return (error); 470 } 471 } 472 if (nfound == 0) 473 return (ECHILD); 474 if (uap->options & WNOHANG) { 475 retval[0] = 0; 476 return (0); 477 } 478 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 479 return (error); 480 goto loop; 481 } 482 483 /* 484 * make process 'parent' the new parent of process 'child'. 485 */ 486 void 487 proc_reparent(child, parent) 488 register struct proc *child; 489 register struct proc *parent; 490 { 491 register struct proc *o; 492 register struct proc *y; 493 494 if (child->p_pptr == parent) 495 return; 496 497 /* fix up the child linkage for the old parent */ 498 o = child->p_osptr; 499 y = child->p_ysptr; 500 if (y) 501 y->p_osptr = o; 502 if (o) 503 o->p_ysptr = y; 504 if (child->p_pptr->p_cptr == child) 505 child->p_pptr->p_cptr = o; 506 507 /* fix up child linkage for new parent */ 508 o = parent->p_cptr; 509 if (o) 510 o->p_ysptr = child; 511 child->p_osptr = o; 512 child->p_ysptr = NULL; 513 parent->p_cptr = child; 514 child->p_pptr = parent; 515 } 516