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 1.19 1995/10/23 19:44:38 swallace 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 73 static int wait1 __P((struct proc *, struct wait_args *, int [], int)); 74 75 /* 76 * exit -- 77 * Death of process. 78 */ 79 __dead void 80 exit(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 } 91 92 /* 93 * Exit: deallocate address space and other resources, change proc state 94 * to zombie, and unlink proc from allproc and parent's lists. Save exit 95 * status and rusage for wait(). Check for child processes and orphan them. 96 */ 97 __dead void 98 exit1(p, rv) 99 register struct proc *p; 100 int rv; 101 { 102 register struct proc *q, *nq; 103 register struct proc **pp; 104 register struct vmspace *vm; 105 106 if (p->p_pid == 1) { 107 printf("init died (signal %d, exit %d)\n", 108 WTERMSIG(rv), WEXITSTATUS(rv)); 109 panic("Going nowhere without my init!"); 110 } 111 #ifdef PGINPROF 112 vmsizmon(); 113 #endif 114 if (p->p_flag & P_PROFIL) 115 stopprofclock(p); 116 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 117 M_ZOMBIE, M_WAITOK); 118 /* 119 * If parent is waiting for us to exit or exec, 120 * P_PPWAIT is set; we will wakeup the parent below. 121 */ 122 p->p_flag &= ~(P_TRACED | P_PPWAIT); 123 p->p_flag |= P_WEXIT; 124 p->p_sigignore = ~0; 125 p->p_siglist = 0; 126 untimeout(realitexpire, (caddr_t)p); 127 128 /* 129 * Close open files and release open-file table. 130 * This may block! 131 */ 132 fdfree(p); 133 134 /* The next two chunks should probably be moved to vmspace_exit. */ 135 vm = p->p_vmspace; 136 #ifdef SYSVSHM 137 if (vm->vm_shm) 138 shmexit(p); 139 #endif 140 /* 141 * Release user portion of address space. 142 * This releases references to vnodes, 143 * which could cause I/O if the file has been unlinked. 144 * Need to do this early enough that we can still sleep. 145 * Can't free the entire vmspace as the kernel stack 146 * may be mapped within that space also. 147 */ 148 if (vm->vm_refcnt == 1) 149 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 150 VM_MAXUSER_ADDRESS); 151 152 if (SESS_LEADER(p)) { 153 register struct session *sp = p->p_session; 154 155 if (sp->s_ttyvp) { 156 /* 157 * Controlling process. 158 * Signal foreground pgrp, 159 * drain controlling terminal 160 * and revoke access to controlling terminal. 161 */ 162 if (sp->s_ttyp->t_session == sp) { 163 if (sp->s_ttyp->t_pgrp) 164 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 165 (void) ttywait(sp->s_ttyp); 166 /* 167 * The tty could have been revoked 168 * if we blocked. 169 */ 170 if (sp->s_ttyvp) 171 vgoneall(sp->s_ttyvp); 172 } 173 if (sp->s_ttyvp) 174 vrele(sp->s_ttyvp); 175 sp->s_ttyvp = NULL; 176 /* 177 * s_ttyp is not zero'd; we use this to indicate 178 * that the session once had a controlling terminal. 179 * (for logging and informational purposes) 180 */ 181 } 182 sp->s_leader = NULL; 183 } 184 fixjobc(p, p->p_pgrp, 0); 185 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 186 (void)acct_process(p); 187 #ifdef KTRACE 188 /* 189 * release trace file 190 */ 191 p->p_traceflag = 0; /* don't trace the vrele() */ 192 if (p->p_tracep) 193 vrele(p->p_tracep); 194 #endif 195 /* 196 * Remove proc from allproc queue and pidhash chain. 197 * Place onto zombproc. Unlink from parent's child list. 198 */ 199 if ((*p->p_prev = p->p_next)) 200 p->p_next->p_prev = p->p_prev; 201 if ((p->p_next = zombproc)) 202 p->p_next->p_prev = &p->p_next; 203 p->p_prev = &zombproc; 204 zombproc = p; 205 p->p_stat = SZOMB; 206 207 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 208 if (*pp == p) { 209 *pp = p->p_hash; 210 goto done; 211 } 212 panic("exit"); 213 done: 214 215 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 216 wakeup((caddr_t) initproc); 217 for (q = p->p_cptr; q != NULL; q = nq) { 218 nq = q->p_osptr; 219 if (nq != NULL) 220 nq->p_ysptr = NULL; 221 if (initproc->p_cptr) 222 initproc->p_cptr->p_ysptr = q; 223 q->p_osptr = initproc->p_cptr; 224 q->p_ysptr = NULL; 225 initproc->p_cptr = q; 226 227 q->p_pptr = initproc; 228 /* 229 * Traced processes are killed 230 * since their existence means someone is screwing up. 231 */ 232 if (q->p_flag & P_TRACED) { 233 q->p_flag &= ~P_TRACED; 234 psignal(q, SIGKILL); 235 } 236 } 237 p->p_cptr = NULL; 238 239 /* 240 * Save exit status and final rusage info, adding in child rusage 241 * info and self times. 242 */ 243 p->p_xstat = rv; 244 *p->p_ru = p->p_stats->p_ru; 245 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 246 ruadd(p->p_ru, &p->p_stats->p_cru); 247 248 /* 249 * Notify parent that we're gone. 250 */ 251 psignal(p->p_pptr, SIGCHLD); 252 wakeup((caddr_t)p->p_pptr); 253 #if defined(tahoe) 254 /* move this to cpu_exit */ 255 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 256 #endif 257 /* 258 * Clear curproc after we've done all operations 259 * that could block, and before tearing down the rest 260 * of the process state that might be used from clock, etc. 261 * Also, can't clear curproc while we're still runnable, 262 * as we're not on a run queue (we are current, just not 263 * a proper proc any longer!). 264 * 265 * Other substructures are freed from wait(). 266 */ 267 curproc = NULL; 268 if (--p->p_limit->p_refcnt == 0) { 269 FREE(p->p_limit, M_SUBPROC); 270 p->p_limit = NULL; 271 } 272 273 /* 274 * Finally, call machine-dependent code to release the remaining 275 * resources including address space, the kernel stack and pcb. 276 * The address space is released by "vmspace_free(p->p_vmspace)"; 277 * This is machine-dependent, as we may have to change stacks 278 * or ensure that the current one isn't reallocated before we 279 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 280 * our execution (pun intended). 281 */ 282 cpu_exit(p); 283 } 284 285 #ifdef COMPAT_43 286 #if defined(hp300) || defined(luna68k) 287 #include <machine/frame.h> 288 #define GETPS(rp) ((struct frame *)(rp))->f_sr 289 #else 290 #define GETPS(rp) (rp)[PS] 291 #endif 292 293 int 294 owait(p, uap, retval) 295 struct proc *p; 296 register struct owait_args /* { 297 int dummy; 298 } */ *uap; 299 int *retval; 300 { 301 struct wait_args w; 302 303 #ifdef PSL_ALLCC 304 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 305 w.options = 0; 306 w.rusage = NULL; 307 } else { 308 w.options = p->p_md.md_regs[R0]; 309 w.rusage = (struct rusage *)p->p_md.md_regs[R1]; 310 } 311 #else 312 w.options = 0; 313 w.rusage = NULL; 314 #endif 315 w.pid = WAIT_ANY; 316 w.status = NULL; 317 return (wait1(p, &w, retval, 1)); 318 } 319 #endif /* COMPAT_43 */ 320 321 int 322 wait4(p, uap, retval) 323 struct proc *p; 324 struct wait_args *uap; 325 int *retval; 326 { 327 328 return (wait1(p, uap, retval, 0)); 329 } 330 331 static int 332 wait1(q, uap, retval, compat) 333 register struct proc *q; 334 register struct wait_args /* { 335 int pid; 336 int *status; 337 int options; 338 struct rusage *rusage; 339 } */ *uap; 340 int retval[]; 341 int compat; 342 { 343 register int nfound; 344 register struct proc *p, *t; 345 int status, error; 346 347 if (uap->pid == 0) 348 uap->pid = -q->p_pgid; 349 #ifdef notyet 350 if (uap->options &~ (WUNTRACED|WNOHANG)) 351 return (EINVAL); 352 #endif 353 loop: 354 nfound = 0; 355 for (p = q->p_cptr; p; p = p->p_osptr) { 356 if (uap->pid != WAIT_ANY && 357 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 358 continue; 359 nfound++; 360 if (p->p_stat == SZOMB) { 361 /* charge childs scheduling cpu usage to parent */ 362 if (curproc->p_pid != 1) { 363 curproc->p_estcpu = min(curproc->p_estcpu + 364 p->p_estcpu, UCHAR_MAX); 365 } 366 367 retval[0] = p->p_pid; 368 #ifdef COMPAT_43 369 if (compat) 370 retval[1] = p->p_xstat; 371 else 372 #endif 373 if (uap->status) { 374 status = p->p_xstat; /* convert to int */ 375 if ((error = copyout((caddr_t)&status, 376 (caddr_t)uap->status, sizeof(status)))) 377 return (error); 378 } 379 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 380 (caddr_t)uap->rusage, sizeof (struct rusage)))) 381 return (error); 382 /* 383 * If we got the child via a ptrace 'attach', 384 * we need to give it back to the old parent. 385 */ 386 if (p->p_oppid && (t = pfind(p->p_oppid))) { 387 p->p_oppid = 0; 388 proc_reparent(p, t); 389 psignal(t, SIGCHLD); 390 wakeup((caddr_t)t); 391 return (0); 392 } 393 p->p_xstat = 0; 394 ruadd(&q->p_stats->p_cru, p->p_ru); 395 FREE(p->p_ru, M_ZOMBIE); 396 p->p_ru = NULL; 397 398 /* 399 * Decrement the count of procs running with this uid. 400 */ 401 (void)chgproccnt(p->p_cred->p_ruid, -1); 402 403 /* 404 * Free up credentials. 405 */ 406 if (--p->p_cred->p_refcnt == 0) { 407 crfree(p->p_cred->pc_ucred); 408 FREE(p->p_cred, M_SUBPROC); 409 p->p_cred = NULL; 410 } 411 412 /* 413 * Release reference to text vnode 414 */ 415 if (p->p_textvp) 416 vrele(p->p_textvp); 417 418 /* 419 * Finally finished with old proc entry. 420 * Unlink it from its process group and free it. 421 */ 422 leavepgrp(p); 423 if ((*p->p_prev = p->p_next)) /* off zombproc */ 424 p->p_next->p_prev = p->p_prev; 425 if ((q = p->p_ysptr)) 426 q->p_osptr = p->p_osptr; 427 if ((q = p->p_osptr)) 428 q->p_ysptr = p->p_ysptr; 429 if ((q = p->p_pptr)->p_cptr == p) 430 q->p_cptr = p->p_osptr; 431 432 /* 433 * Give machine-dependent layer a chance 434 * to free anything that cpu_exit couldn't 435 * release while still running in process context. 436 */ 437 cpu_wait(p); 438 FREE(p, M_PROC); 439 nprocs--; 440 return (0); 441 } 442 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 443 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 444 p->p_flag |= P_WAITED; 445 retval[0] = p->p_pid; 446 #ifdef COMPAT_43 447 if (compat) { 448 retval[1] = W_STOPCODE(p->p_xstat); 449 error = 0; 450 } else 451 #endif 452 if (uap->status) { 453 status = W_STOPCODE(p->p_xstat); 454 error = copyout((caddr_t)&status, 455 (caddr_t)uap->status, sizeof(status)); 456 } else 457 error = 0; 458 return (error); 459 } 460 } 461 if (nfound == 0) 462 return (ECHILD); 463 if (uap->options & WNOHANG) { 464 retval[0] = 0; 465 return (0); 466 } 467 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))) 468 return (error); 469 goto loop; 470 } 471 472 /* 473 * make process 'parent' the new parent of process 'child'. 474 */ 475 void 476 proc_reparent(child, parent) 477 register struct proc *child; 478 register struct proc *parent; 479 { 480 register struct proc *o; 481 register struct proc *y; 482 483 if (child->p_pptr == parent) 484 return; 485 486 /* fix up the child linkage for the old parent */ 487 o = child->p_osptr; 488 y = child->p_ysptr; 489 if (y) 490 y->p_osptr = o; 491 if (o) 492 o->p_ysptr = y; 493 if (child->p_pptr->p_cptr == child) 494 child->p_pptr->p_cptr = o; 495 496 /* fix up child linkage for new parent */ 497 o = parent->p_cptr; 498 if (o) 499 o->p_ysptr = child; 500 child->p_osptr = o; 501 child->p_ysptr = NULL; 502 parent->p_cptr = child; 503 child->p_pptr = parent; 504 } 505