1 /* $NetBSD: kern_exit.c,v 1.46 1998/01/03 02:48:43 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/map.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/proc.h> 53 #include <sys/buf.h> 54 #include <sys/wait.h> 55 #include <sys/file.h> 56 #include <sys/vnode.h> 57 #include <sys/syslog.h> 58 #include <sys/malloc.h> 59 #include <sys/resourcevar.h> 60 #include <sys/ptrace.h> 61 #include <sys/acct.h> 62 #include <sys/filedesc.h> 63 #include <sys/signalvar.h> 64 #ifdef SYSVSHM 65 #include <sys/shm.h> 66 #endif 67 #ifdef SYSVSEM 68 #include <sys/sem.h> 69 #endif 70 71 #include <sys/mount.h> 72 #include <sys/syscallargs.h> 73 74 #include <machine/cpu.h> 75 76 #include <vm/vm.h> 77 #include <vm/vm_kern.h> 78 79 /* 80 * exit -- 81 * Death of process. 82 */ 83 int 84 sys_exit(p, v, retval) 85 struct proc *p; 86 void *v; 87 register_t *retval; 88 { 89 struct sys_exit_args /* { 90 syscallarg(int) rval; 91 } */ *uap = v; 92 93 exit1(p, W_EXITCODE(SCARG(uap, rval), 0)); 94 /* NOTREACHED */ 95 return (0); 96 } 97 98 /* 99 * Exit: deallocate address space and other resources, change proc state 100 * to zombie, and unlink proc from allproc and parent's lists. Save exit 101 * status and rusage for wait(). Check for child processes and orphan them. 102 */ 103 void 104 exit1(p, rv) 105 register struct proc *p; 106 int rv; 107 { 108 register struct proc *q, *nq; 109 register struct vmspace *vm; 110 111 if (p->p_pid == 1) 112 panic("init died (signal %d, exit %d)", 113 WTERMSIG(rv), WEXITSTATUS(rv)); 114 #ifdef PGINPROF 115 vmsizmon(); 116 #endif 117 if (p->p_flag & P_PROFIL) 118 stopprofclock(p); 119 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 120 M_ZOMBIE, M_WAITOK); 121 /* 122 * If parent is waiting for us to exit or exec, P_PPWAIT is set; we 123 * wake up the parent early to avoid deadlock. 124 */ 125 p->p_flag |= P_WEXIT; 126 if (p->p_flag & P_PPWAIT) { 127 p->p_flag &= ~P_PPWAIT; 128 wakeup((caddr_t)p->p_pptr); 129 } 130 p->p_sigignore = ~0; 131 p->p_siglist = 0; 132 untimeout(realitexpire, (caddr_t)p); 133 134 /* 135 * Close open files and release open-file table. 136 * This may block! 137 */ 138 fdfree(p); 139 140 /* The next three chunks should probably be moved to vmspace_exit. */ 141 vm = p->p_vmspace; 142 #ifdef SYSVSHM 143 if (vm->vm_shm && vm->vm_refcnt == 1) 144 shmexit(vm); 145 #endif 146 #ifdef SYSVSEM 147 semexit(p); 148 #endif 149 /* 150 * Release user portion of address space. 151 * This releases references to vnodes, 152 * which could cause I/O if the file has been unlinked. 153 * Need to do this early enough that we can still sleep. 154 * Can't free the entire vmspace as the kernel stack 155 * may be mapped within that space also. 156 */ 157 if (vm->vm_refcnt == 1) 158 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 159 VM_MAXUSER_ADDRESS); 160 161 if (SESS_LEADER(p)) { 162 register struct session *sp = p->p_session; 163 164 if (sp->s_ttyvp) { 165 /* 166 * Controlling process. 167 * Signal foreground pgrp, 168 * drain controlling terminal 169 * and revoke access to controlling terminal. 170 */ 171 if (sp->s_ttyp->t_session == sp) { 172 if (sp->s_ttyp->t_pgrp) 173 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 174 (void) ttywait(sp->s_ttyp); 175 /* 176 * The tty could have been revoked 177 * if we blocked. 178 */ 179 if (sp->s_ttyvp) 180 vgoneall(sp->s_ttyvp); 181 } 182 if (sp->s_ttyvp) 183 vrele(sp->s_ttyvp); 184 sp->s_ttyvp = NULL; 185 /* 186 * s_ttyp is not zero'd; we use this to indicate 187 * that the session once had a controlling terminal. 188 * (for logging and informational purposes) 189 */ 190 } 191 sp->s_leader = NULL; 192 } 193 fixjobc(p, p->p_pgrp, 0); 194 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 195 (void)acct_process(p); 196 #ifdef KTRACE 197 /* 198 * release trace file 199 */ 200 p->p_traceflag = 0; /* don't trace the vrele() */ 201 if (p->p_tracep) 202 vrele(p->p_tracep); 203 #endif 204 /* 205 * Remove proc from allproc queue and pidhash chain. 206 * Place onto zombproc. Unlink from parent's child list. 207 */ 208 LIST_REMOVE(p, p_list); 209 LIST_INSERT_HEAD(&zombproc, p, p_list); 210 p->p_stat = SZOMB; 211 212 LIST_REMOVE(p, p_hash); 213 214 q = p->p_children.lh_first; 215 if (q) /* only need this if any child is S_ZOMB */ 216 wakeup((caddr_t)initproc); 217 for (; q != 0; q = nq) { 218 nq = q->p_sibling.le_next; 219 proc_reparent(q, initproc); 220 /* 221 * Traced processes are killed 222 * since their existence means someone is screwing up. 223 */ 224 if (q->p_flag & P_TRACED) { 225 q->p_flag &= ~(P_TRACED|P_WAITED|P_FSTRACE); 226 psignal(q, SIGKILL); 227 } 228 } 229 230 /* 231 * Save exit status and final rusage info, adding in child rusage 232 * info and self times. 233 */ 234 p->p_xstat = rv; 235 *p->p_ru = p->p_stats->p_ru; 236 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 237 ruadd(p->p_ru, &p->p_stats->p_cru); 238 239 /* 240 * Notify parent that we're gone. 241 */ 242 if ((p->p_flag & P_FSTRACE) == 0) 243 psignal(p->p_pptr, SIGCHLD); 244 wakeup((caddr_t)p->p_pptr); 245 246 /* 247 * Clear curproc after we've done all operations 248 * that could block, and before tearing down the rest 249 * of the process state that might be used from clock, etc. 250 * Also, can't clear curproc while we're still runnable, 251 * as we're not on a run queue (we are current, just not 252 * a proper proc any longer!). 253 * 254 * Other substructures are freed from wait(). 255 */ 256 curproc = NULL; 257 if (--p->p_limit->p_refcnt == 0) 258 FREE(p->p_limit, M_SUBPROC); 259 260 /* 261 * Finally, call machine-dependent code to release the remaining 262 * resources including address space, the kernel stack and pcb. 263 * The address space is released by "vmspace_free(p->p_vmspace)"; 264 * This is machine-dependent, as we may have to change stacks 265 * or ensure that the current one isn't reallocated before we 266 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 267 * our execution (pun intended). 268 */ 269 cpu_exit(p); 270 } 271 272 int 273 sys_wait4(q, v, retval) 274 register struct proc *q; 275 void *v; 276 register_t *retval; 277 { 278 register struct sys_wait4_args /* { 279 syscallarg(int) pid; 280 syscallarg(int *) status; 281 syscallarg(int) options; 282 syscallarg(struct rusage *) rusage; 283 } */ *uap = v; 284 register int nfound; 285 register struct proc *p, *t; 286 int status, error; 287 288 if (SCARG(uap, pid) == 0) 289 SCARG(uap, pid) = -q->p_pgid; 290 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG)) 291 return (EINVAL); 292 293 loop: 294 nfound = 0; 295 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 296 if (SCARG(uap, pid) != WAIT_ANY && 297 p->p_pid != SCARG(uap, pid) && 298 p->p_pgid != -SCARG(uap, pid)) 299 continue; 300 nfound++; 301 if (p->p_stat == SZOMB) { 302 retval[0] = p->p_pid; 303 304 if (SCARG(uap, status)) { 305 status = p->p_xstat; /* convert to int */ 306 error = copyout((caddr_t)&status, 307 (caddr_t)SCARG(uap, status), 308 sizeof(status)); 309 if (error) 310 return (error); 311 } 312 if (SCARG(uap, rusage) && 313 (error = copyout((caddr_t)p->p_ru, 314 (caddr_t)SCARG(uap, rusage), 315 sizeof (struct rusage)))) 316 return (error); 317 /* 318 * If we got the child via ptrace(2) or procfs, and 319 * the parent is different (meaning the process was 320 * attached, rather than run as a child), then we need 321 * to give it back to the old parent, and send the 322 * parent a SIGCHLD. The rest of the cleanup will be 323 * done when the old parent waits on the child. 324 */ 325 if ((p->p_flag & P_TRACED) && 326 p->p_oppid != p->p_pptr->p_pid) { 327 t = pfind(p->p_oppid); 328 proc_reparent(p, t ? t : initproc); 329 p->p_oppid = 0; 330 p->p_flag &= ~(P_TRACED|P_WAITED|P_FSTRACE); 331 psignal(p->p_pptr, SIGCHLD); 332 wakeup((caddr_t)p->p_pptr); 333 return (0); 334 } 335 p->p_xstat = 0; 336 ruadd(&q->p_stats->p_cru, p->p_ru); 337 FREE(p->p_ru, M_ZOMBIE); 338 339 /* 340 * Finally finished with old proc entry. 341 * Unlink it from its process group and free it. 342 */ 343 leavepgrp(p); 344 LIST_REMOVE(p, p_list); /* off zombproc */ 345 LIST_REMOVE(p, p_sibling); 346 347 /* 348 * Decrement the count of procs running with this uid. 349 */ 350 (void)chgproccnt(p->p_cred->p_ruid, -1); 351 352 /* 353 * Free up credentials. 354 */ 355 if (--p->p_cred->p_refcnt == 0) { 356 crfree(p->p_cred->pc_ucred); 357 FREE(p->p_cred, M_SUBPROC); 358 } 359 360 /* 361 * Release reference to text vnode 362 */ 363 if (p->p_textvp) 364 vrele(p->p_textvp); 365 366 /* 367 * Give machine-dependent layer a chance 368 * to free anything that cpu_exit couldn't 369 * release while still running in process context. 370 */ 371 cpu_wait(p); 372 FREE(p, M_PROC); 373 nprocs--; 374 return (0); 375 } 376 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 377 (p->p_flag & P_TRACED || SCARG(uap, options) & WUNTRACED)) { 378 p->p_flag |= P_WAITED; 379 retval[0] = p->p_pid; 380 381 if (SCARG(uap, status)) { 382 status = W_STOPCODE(p->p_xstat); 383 error = copyout((caddr_t)&status, 384 (caddr_t)SCARG(uap, status), 385 sizeof(status)); 386 } else 387 error = 0; 388 return (error); 389 } 390 } 391 if (nfound == 0) 392 return (ECHILD); 393 if (SCARG(uap, options) & WNOHANG) { 394 retval[0] = 0; 395 return (0); 396 } 397 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) != 0) 398 return (error); 399 goto loop; 400 } 401 402 /* 403 * make process 'parent' the new parent of process 'child'. 404 */ 405 void 406 proc_reparent(child, parent) 407 register struct proc *child; 408 register struct proc *parent; 409 { 410 411 if (child->p_pptr == parent) 412 return; 413 414 LIST_REMOVE(child, p_sibling); 415 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 416 child->p_pptr = parent; 417 } 418