kern_exit.c revision 1.37
1 /* $NetBSD: kern_exit.c,v 1.37 1996/02/09 01:19:21 mycroft 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 65 #include <sys/mount.h> 66 #include <sys/syscallargs.h> 67 68 #include <machine/cpu.h> 69 70 #include <vm/vm.h> 71 #include <vm/vm_kern.h> 72 73 #include <kern/kern_extern.h> 74 75 /* 76 * exit -- 77 * Death of process. 78 */ 79 int 80 sys_exit(p, v, retval) 81 struct proc *p; 82 void *v; 83 register_t *retval; 84 { 85 struct sys_exit_args /* { 86 syscallarg(int) rval; 87 } */ *uap = v; 88 89 exit1(p, W_EXITCODE(SCARG(uap, rval), 0)); 90 /* NOTREACHED */ 91 return (0); 92 } 93 94 /* 95 * Exit: deallocate address space and other resources, change proc state 96 * to zombie, and unlink proc from allproc and parent's lists. Save exit 97 * status and rusage for wait(). Check for child processes and orphan them. 98 */ 99 void 100 exit1(p, rv) 101 register struct proc *p; 102 int rv; 103 { 104 register struct proc *q, *nq; 105 register struct vmspace *vm; 106 107 if (p->p_pid == 1) 108 panic("init died (signal %d, exit %d)", 109 WTERMSIG(rv), WEXITSTATUS(rv)); 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, P_PPWAIT is set; we 119 * wake up the parent early to avoid deadlock. 120 */ 121 p->p_flag |= P_WEXIT; 122 p->p_flag &= ~P_TRACED; 123 if (p->p_flag & P_PPWAIT) { 124 p->p_flag &= ~P_PPWAIT; 125 wakeup((caddr_t)p->p_pptr); 126 } 127 p->p_sigignore = ~0; 128 p->p_siglist = 0; 129 untimeout(realitexpire, (caddr_t)p); 130 131 /* 132 * Close open files and release open-file table. 133 * This may block! 134 */ 135 fdfree(p); 136 137 /* The next three chunks should probably be moved to vmspace_exit. */ 138 vm = p->p_vmspace; 139 #ifdef SYSVSHM 140 if (vm->vm_shm) 141 shmexit(p); 142 #endif 143 #ifdef SYSVSEM 144 semexit(p); 145 #endif 146 /* 147 * Release user portion of address space. 148 * This releases references to vnodes, 149 * which could cause I/O if the file has been unlinked. 150 * Need to do this early enough that we can still sleep. 151 * Can't free the entire vmspace as the kernel stack 152 * may be mapped within that space also. 153 */ 154 if (vm->vm_refcnt == 1) 155 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 156 VM_MAXUSER_ADDRESS); 157 158 if (SESS_LEADER(p)) { 159 register struct session *sp = p->p_session; 160 161 if (sp->s_ttyvp) { 162 /* 163 * Controlling process. 164 * Signal foreground pgrp, 165 * drain controlling terminal 166 * and revoke access to controlling terminal. 167 */ 168 if (sp->s_ttyp->t_session == sp) { 169 if (sp->s_ttyp->t_pgrp) 170 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 171 (void) ttywait(sp->s_ttyp); 172 /* 173 * The tty could have been revoked 174 * if we blocked. 175 */ 176 if (sp->s_ttyvp) 177 vgoneall(sp->s_ttyvp); 178 } 179 if (sp->s_ttyvp) 180 vrele(sp->s_ttyvp); 181 sp->s_ttyvp = NULL; 182 /* 183 * s_ttyp is not zero'd; we use this to indicate 184 * that the session once had a controlling terminal. 185 * (for logging and informational purposes) 186 */ 187 } 188 sp->s_leader = NULL; 189 } 190 fixjobc(p, p->p_pgrp, 0); 191 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 192 (void)acct_process(p); 193 #ifdef KTRACE 194 /* 195 * release trace file 196 */ 197 p->p_traceflag = 0; /* don't trace the vrele() */ 198 if (p->p_tracep) 199 vrele(p->p_tracep); 200 #endif 201 /* 202 * Remove proc from allproc queue and pidhash chain. 203 * Place onto zombproc. Unlink from parent's child list. 204 */ 205 LIST_REMOVE(p, p_list); 206 LIST_INSERT_HEAD(&zombproc, p, p_list); 207 p->p_stat = SZOMB; 208 209 LIST_REMOVE(p, p_hash); 210 211 q = p->p_children.lh_first; 212 if (q) /* only need this if any child is S_ZOMB */ 213 wakeup((caddr_t)initproc); 214 for (; q != 0; q = nq) { 215 nq = q->p_sibling.le_next; 216 proc_reparent(q, initproc); 217 /* 218 * Traced processes are killed 219 * since their existence means someone is screwing up. 220 */ 221 if (q->p_flag & P_TRACED) { 222 q->p_flag &= ~P_TRACED; 223 psignal(q, SIGKILL); 224 } 225 } 226 227 /* 228 * Save exit status and final rusage info, adding in child rusage 229 * info and self times. 230 */ 231 p->p_xstat = rv; 232 *p->p_ru = p->p_stats->p_ru; 233 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 234 ruadd(p->p_ru, &p->p_stats->p_cru); 235 236 /* 237 * Notify parent that we're gone. 238 */ 239 psignal(p->p_pptr, SIGCHLD); 240 wakeup((caddr_t)p->p_pptr); 241 /* 242 * Notify procfs debugger 243 */ 244 if (p->p_flag & P_FSTRACE) 245 wakeup((caddr_t)p); 246 #if defined(tahoe) 247 /* move this to cpu_exit */ 248 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 249 #endif 250 /* 251 * Clear curproc after we've done all operations 252 * that could block, and before tearing down the rest 253 * of the process state that might be used from clock, etc. 254 * Also, can't clear curproc while we're still runnable, 255 * as we're not on a run queue (we are current, just not 256 * a proper proc any longer!). 257 * 258 * Other substructures are freed from wait(). 259 */ 260 curproc = NULL; 261 if (--p->p_limit->p_refcnt == 0) 262 FREE(p->p_limit, M_SUBPROC); 263 264 /* 265 * Finally, call machine-dependent code to release the remaining 266 * resources including address space, the kernel stack and pcb. 267 * The address space is released by "vmspace_free(p->p_vmspace)"; 268 * This is machine-dependent, as we may have to change stacks 269 * or ensure that the current one isn't reallocated before we 270 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 271 * our execution (pun intended). 272 */ 273 cpu_exit(p); 274 } 275 276 int 277 sys_wait4(q, v, retval) 278 register struct proc *q; 279 void *v; 280 register_t *retval; 281 { 282 register struct sys_wait4_args /* { 283 syscallarg(int) pid; 284 syscallarg(int *) status; 285 syscallarg(int) options; 286 syscallarg(struct rusage *) rusage; 287 } */ *uap = v; 288 register int nfound; 289 register struct proc *p, *t; 290 int status, error; 291 292 #ifdef COMPAT_09 293 SCARG(uap, pid) = (short)SCARG(uap, pid); 294 #endif 295 296 if (SCARG(uap, pid) == 0) 297 SCARG(uap, pid) = -q->p_pgid; 298 #ifdef notyet 299 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG)) 300 return (EINVAL); 301 #endif 302 loop: 303 nfound = 0; 304 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 305 if (SCARG(uap, pid) != WAIT_ANY && 306 p->p_pid != SCARG(uap, pid) && 307 p->p_pgid != -SCARG(uap, pid)) 308 continue; 309 nfound++; 310 if (p->p_stat == SZOMB) { 311 retval[0] = p->p_pid; 312 313 if (SCARG(uap, status)) { 314 status = p->p_xstat; /* convert to int */ 315 error = copyout((caddr_t)&status, 316 (caddr_t)SCARG(uap, status), 317 sizeof(status)); 318 if (error) 319 return (error); 320 } 321 if (SCARG(uap, rusage) && 322 (error = copyout((caddr_t)p->p_ru, 323 (caddr_t)SCARG(uap, rusage), 324 sizeof (struct rusage)))) 325 return (error); 326 /* 327 * If we got the child via a ptrace 'attach', 328 * we need to give it back to the old parent. 329 */ 330 if (p->p_oppid && (t = pfind(p->p_oppid))) { 331 p->p_oppid = 0; 332 proc_reparent(p, t); 333 psignal(t, SIGCHLD); 334 wakeup((caddr_t)t); 335 return (0); 336 } 337 p->p_xstat = 0; 338 ruadd(&q->p_stats->p_cru, p->p_ru); 339 FREE(p->p_ru, M_ZOMBIE); 340 341 /* 342 * Finally finished with old proc entry. 343 * Unlink it from its process group and free it. 344 */ 345 leavepgrp(p); 346 LIST_REMOVE(p, p_list); /* off zombproc */ 347 LIST_REMOVE(p, p_sibling); 348 349 /* 350 * Decrement the count of procs running with this uid. 351 */ 352 (void)chgproccnt(p->p_cred->p_ruid, -1); 353 354 /* 355 * Free up credentials. 356 */ 357 if (--p->p_cred->p_refcnt == 0) { 358 crfree(p->p_cred->pc_ucred); 359 FREE(p->p_cred, M_SUBPROC); 360 } 361 362 /* 363 * Release reference to text vnode 364 */ 365 if (p->p_textvp) 366 vrele(p->p_textvp); 367 368 /* 369 * Give machine-dependent layer a chance 370 * to free anything that cpu_exit couldn't 371 * release while still running in process context. 372 */ 373 cpu_wait(p); 374 FREE(p, M_PROC); 375 nprocs--; 376 return (0); 377 } 378 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 379 (p->p_flag & P_TRACED || SCARG(uap, options) & WUNTRACED)) { 380 p->p_flag |= P_WAITED; 381 retval[0] = p->p_pid; 382 383 if (SCARG(uap, status)) { 384 status = W_STOPCODE(p->p_xstat); 385 error = copyout((caddr_t)&status, 386 (caddr_t)SCARG(uap, status), 387 sizeof(status)); 388 } else 389 error = 0; 390 return (error); 391 } 392 } 393 if (nfound == 0) 394 return (ECHILD); 395 if (SCARG(uap, options) & WNOHANG) { 396 retval[0] = 0; 397 return (0); 398 } 399 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) != 0) 400 return (error); 401 goto loop; 402 } 403 404 /* 405 * make process 'parent' the new parent of process 'child'. 406 */ 407 void 408 proc_reparent(child, parent) 409 register struct proc *child; 410 register struct proc *parent; 411 { 412 413 if (child->p_pptr == parent) 414 return; 415 416 LIST_REMOVE(child, p_sibling); 417 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 418 child->p_pptr = parent; 419 } 420
Indexes created Thu Sep 25 14:09:45 GMT 2025