1 /* $OpenBSD: kern_exit.c,v 1.21 2000/02/21 20:00:09 art Exp $ */ 2 /* $NetBSD: kern_exit.c,v 1.39 1996/04/22 01:38:25 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/map.h> 47 #include <sys/ioctl.h> 48 #include <sys/proc.h> 49 #include <sys/tty.h> 50 #include <sys/time.h> 51 #include <sys/resource.h> 52 #include <sys/kernel.h> 53 #include <sys/proc.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/ptrace.h> 62 #include <sys/acct.h> 63 #include <sys/filedesc.h> 64 #include <sys/signalvar.h> 65 #include <sys/sched.h> 66 #ifdef SYSVSHM 67 #include <sys/shm.h> 68 #endif 69 #ifdef SYSVSEM 70 #include <sys/sem.h> 71 #endif 72 73 #include <sys/mount.h> 74 #include <sys/syscallargs.h> 75 76 #include <machine/cpu.h> 77 78 #include <vm/vm.h> 79 #include <vm/vm_kern.h> 80 81 #if defined(UVM) 82 #include <uvm/uvm_extern.h> 83 #endif 84 85 /* 86 * exit -- 87 * Death of process. 88 */ 89 int 90 sys_exit(p, v, retval) 91 struct proc *p; 92 void *v; 93 register_t *retval; 94 { 95 struct sys_exit_args /* { 96 syscallarg(int) rval; 97 } */ *uap = v; 98 99 exit1(p, W_EXITCODE(SCARG(uap, rval), 0)); 100 /* NOTREACHED */ 101 return (0); 102 } 103 104 /* 105 * Exit: deallocate address space and other resources, change proc state 106 * to zombie, and unlink proc from allproc and parent's lists. Save exit 107 * status and rusage for wait(). Check for child processes and orphan them. 108 */ 109 void 110 exit1(p, rv) 111 register struct proc *p; 112 int rv; 113 { 114 register struct proc *q, *nq; 115 register struct vmspace *vm; 116 117 if (p->p_pid == 1) 118 panic("init died (signal %d, exit %d)", 119 WTERMSIG(rv), WEXITSTATUS(rv)); 120 121 if (p->p_flag & P_PROFIL) 122 stopprofclock(p); 123 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 124 M_ZOMBIE, M_WAITOK); 125 /* 126 * If parent is waiting for us to exit or exec, P_PPWAIT is set; we 127 * wake up the parent early to avoid deadlock. 128 */ 129 p->p_flag |= P_WEXIT; 130 p->p_flag &= ~P_TRACED; 131 if (p->p_flag & P_PPWAIT) { 132 p->p_flag &= ~P_PPWAIT; 133 wakeup((caddr_t)p->p_pptr); 134 } 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 /* The next three chunks should probably be moved to vmspace_exit. */ 146 vm = p->p_vmspace; 147 #ifdef SYSVSHM 148 if (vm->vm_shm && vm->vm_refcnt == 1) 149 shmexit(vm); 150 #endif 151 #ifdef SYSVSEM 152 semexit(p); 153 #endif 154 /* 155 * Release user portion of address space. 156 * This releases references to vnodes, 157 * which could cause I/O if the file has been unlinked. 158 * Need to do this early enough that we can still sleep. 159 * Can't free the entire vmspace as the kernel stack 160 * may be mapped within that space also. 161 */ 162 #if defined(UVM) 163 if (vm->vm_refcnt == 1) 164 (void) uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 165 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 166 #else 167 if (vm->vm_refcnt == 1) 168 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 169 VM_MAXUSER_ADDRESS); 170 #endif 171 172 if (SESS_LEADER(p)) { 173 register struct session *sp = p->p_session; 174 175 if (sp->s_ttyvp) { 176 /* 177 * Controlling process. 178 * Signal foreground pgrp, 179 * drain controlling terminal 180 * and revoke access to controlling terminal. 181 */ 182 if (sp->s_ttyp->t_session == sp) { 183 if (sp->s_ttyp->t_pgrp) 184 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 185 (void) ttywait(sp->s_ttyp); 186 /* 187 * The tty could have been revoked 188 * if we blocked. 189 */ 190 if (sp->s_ttyvp) 191 VOP_REVOKE(sp->s_ttyvp, REVOKEALL); 192 } 193 if (sp->s_ttyvp) 194 vrele(sp->s_ttyvp); 195 sp->s_ttyvp = NULL; 196 /* 197 * s_ttyp is not zero'd; we use this to indicate 198 * that the session once had a controlling terminal. 199 * (for logging and informational purposes) 200 */ 201 } 202 sp->s_leader = NULL; 203 } 204 fixjobc(p, p->p_pgrp, 0); 205 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 206 (void)acct_process(p); 207 #ifdef KTRACE 208 /* 209 * release trace file 210 */ 211 p->p_traceflag = 0; /* don't trace the vrele() */ 212 if (p->p_tracep) 213 vrele(p->p_tracep); 214 #endif 215 /* 216 * Remove proc from allproc queue and pidhash chain. 217 * Place onto zombproc. Unlink from parent's child list. 218 */ 219 LIST_REMOVE(p, p_list); 220 LIST_INSERT_HEAD(&zombproc, p, p_list); 221 p->p_stat = SZOMB; 222 223 LIST_REMOVE(p, p_hash); 224 225 q = p->p_children.lh_first; 226 if (q) /* only need this if any child is S_ZOMB */ 227 wakeup((caddr_t)initproc); 228 for (; q != 0; q = nq) { 229 nq = q->p_sibling.le_next; 230 proc_reparent(q, initproc); 231 /* 232 * Traced processes are killed 233 * since their existence means someone is screwing up. 234 */ 235 if (q->p_flag & P_TRACED) { 236 q->p_flag &= ~P_TRACED; 237 psignal(q, SIGKILL); 238 } 239 } 240 241 /* 242 * Save exit status and final rusage info, adding in child rusage 243 * info and self times. 244 */ 245 p->p_xstat = rv; 246 *p->p_ru = p->p_stats->p_ru; 247 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 248 ruadd(p->p_ru, &p->p_stats->p_cru); 249 250 /* 251 * clear %cpu usage during swap 252 */ 253 p->p_pctcpu = 0; 254 255 /* 256 * Notify parent that we're gone. If we have P_NOZOMBIE or parent has 257 * the P_NOCLDWAIT flag set, notify process 1 instead (and hope it 258 * will handle this situation). 259 */ 260 if ((p->p_flag & P_NOZOMBIE) || (p->p_pptr->p_flag & P_NOCLDWAIT)) { 261 struct proc *pp = p->p_pptr; 262 proc_reparent(p, initproc); 263 /* 264 * If this was the last child of our parent, notify 265 * parent, so in case he was wait(2)ing, he will 266 * continue. 267 */ 268 if (pp->p_children.lh_first == NULL) 269 wakeup((caddr_t)pp); 270 } 271 psignal(p->p_pptr, SIGCHLD); 272 wakeup((caddr_t)p->p_pptr); 273 274 /* 275 * Notify procfs debugger 276 */ 277 if (p->p_flag & P_FSTRACE) 278 wakeup((caddr_t)p); 279 #if defined(tahoe) 280 /* move this to cpu_exit */ 281 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 282 #endif 283 /* 284 * Clear curproc after we've done all operations 285 * that could block, and before tearing down the rest 286 * of the process state that might be used from clock, etc. 287 * Also, can't clear curproc while we're still runnable, 288 * as we're not on a run queue (we are current, just not 289 * a proper proc any longer!). 290 * 291 * Other substructures are freed from wait(). 292 */ 293 curproc = NULL; 294 if (--p->p_limit->p_refcnt == 0) 295 FREE(p->p_limit, M_SUBPROC); 296 297 /* 298 * Finally, call machine-dependent code to release the remaining 299 * resources including address space, the kernel stack and pcb. 300 * The address space is released by "vmspace_free(p->p_vmspace)"; 301 * This is machine-dependent, as we may have to change stacks 302 * or ensure that the current one isn't reallocated before we 303 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 304 * our execution (pun intended). 305 */ 306 cpu_exit(p); 307 } 308 309 int 310 sys_wait4(q, v, retval) 311 register struct proc *q; 312 void *v; 313 register_t *retval; 314 { 315 register struct sys_wait4_args /* { 316 syscallarg(int) pid; 317 syscallarg(int *) status; 318 syscallarg(int) options; 319 syscallarg(struct rusage *) rusage; 320 } */ *uap = v; 321 register int nfound; 322 register struct proc *p, *t; 323 int status, error; 324 325 #ifdef COMPAT_09 326 SCARG(uap, pid) = (short)SCARG(uap, pid); 327 #endif 328 329 if (SCARG(uap, pid) == 0) 330 SCARG(uap, pid) = -q->p_pgid; 331 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG)) 332 return (EINVAL); 333 334 loop: 335 nfound = 0; 336 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 337 if ((p->p_flag & P_NOZOMBIE) || 338 (SCARG(uap, pid) != WAIT_ANY && 339 p->p_pid != SCARG(uap, pid) && 340 p->p_pgid != -SCARG(uap, pid))) 341 continue; 342 nfound++; 343 if (p->p_stat == SZOMB) { 344 retval[0] = p->p_pid; 345 346 if (SCARG(uap, status)) { 347 status = p->p_xstat; /* convert to int */ 348 error = copyout((caddr_t)&status, 349 (caddr_t)SCARG(uap, status), 350 sizeof(status)); 351 if (error) 352 return (error); 353 } 354 if (SCARG(uap, rusage) && 355 (error = copyout((caddr_t)p->p_ru, 356 (caddr_t)SCARG(uap, rusage), 357 sizeof (struct rusage)))) 358 return (error); 359 /* 360 * If we got the child via a ptrace 'attach', 361 * we need to give it back to the old parent. 362 */ 363 if (p->p_oppid && (t = pfind(p->p_oppid))) { 364 p->p_oppid = 0; 365 proc_reparent(p, t); 366 psignal(t, SIGCHLD); 367 wakeup((caddr_t)t); 368 return (0); 369 } 370 371 scheduler_wait_hook(curproc, p); 372 p->p_xstat = 0; 373 ruadd(&q->p_stats->p_cru, p->p_ru); 374 FREE(p->p_ru, M_ZOMBIE); 375 376 /* 377 * Finally finished with old proc entry. 378 * Unlink it from its process group and free it. 379 */ 380 leavepgrp(p); 381 LIST_REMOVE(p, p_list); /* off zombproc */ 382 LIST_REMOVE(p, p_sibling); 383 384 /* 385 * Decrement the count of procs running with this uid. 386 */ 387 (void)chgproccnt(p->p_cred->p_ruid, -1); 388 389 /* 390 * Free up credentials. 391 */ 392 if (--p->p_cred->p_refcnt == 0) { 393 crfree(p->p_cred->pc_ucred); 394 FREE(p->p_cred, M_SUBPROC); 395 } 396 397 /* 398 * Release reference to text vnode 399 */ 400 if (p->p_textvp) 401 vrele(p->p_textvp); 402 403 /* 404 * Give machine-dependent layer a chance 405 * to free anything that cpu_exit couldn't 406 * release while still running in process context. 407 */ 408 cpu_wait(p); 409 FREE(p, M_PROC); 410 nprocs--; 411 return (0); 412 } 413 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 414 (p->p_flag & P_TRACED || SCARG(uap, options) & WUNTRACED)) { 415 p->p_flag |= P_WAITED; 416 retval[0] = p->p_pid; 417 418 if (SCARG(uap, status)) { 419 status = W_STOPCODE(p->p_xstat); 420 error = copyout((caddr_t)&status, 421 (caddr_t)SCARG(uap, status), 422 sizeof(status)); 423 } else 424 error = 0; 425 return (error); 426 } 427 } 428 if (nfound == 0) 429 return (ECHILD); 430 if (SCARG(uap, options) & WNOHANG) { 431 retval[0] = 0; 432 return (0); 433 } 434 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) != 0) 435 return (error); 436 goto loop; 437 } 438 439 /* 440 * make process 'parent' the new parent of process 'child'. 441 */ 442 void 443 proc_reparent(child, parent) 444 register struct proc *child; 445 register struct proc *parent; 446 { 447 448 if (child->p_pptr == parent) 449 return; 450 451 LIST_REMOVE(child, p_sibling); 452 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 453 child->p_pptr = parent; 454 } 455