kern_exit.c revision 1.35
1 /* $NetBSD: kern_exit.c,v 1.35 1995/12/24 11:23:33 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 63 #include <sys/mount.h> 64 #include <sys/syscallargs.h> 65 66 #include <machine/cpu.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_kern.h> 70 71 void cpu_exit __P((struct proc *)); /* XXX MOVE ME */ 72 void exit1 __P((struct proc *, int)); 73 74 /* 75 * exit -- 76 * Death of process. 77 */ 78 int 79 sys_exit(p, v, retval) 80 struct proc *p; 81 void *v; 82 register_t *retval; 83 { 84 struct sys_exit_args /* { 85 syscallarg(int) rval; 86 } */ *uap = v; 87 88 exit1(p, W_EXITCODE(SCARG(uap, rval), 0)); 89 /* NOTREACHED */ 90 return (0); 91 } 92 93 /* 94 * Exit: deallocate address space and other resources, change proc state 95 * to zombie, and unlink proc from allproc and parent's lists. Save exit 96 * status and rusage for wait(). Check for child processes and orphan them. 97 */ 98 void 99 exit1(p, rv) 100 register struct proc *p; 101 int rv; 102 { 103 register struct proc *q, *nq; 104 register struct vmspace *vm; 105 106 if (p->p_pid == 1) 107 panic("init died (signal %d, exit %d)", 108 WTERMSIG(rv), WEXITSTATUS(rv)); 109 #ifdef PGINPROF 110 vmsizmon(); 111 #endif 112 if (p->p_flag & P_PROFIL) 113 stopprofclock(p); 114 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 115 M_ZOMBIE, M_WAITOK); 116 /* 117 * If parent is waiting for us to exit or exec, 118 * P_PPWAIT is set; we will wakeup the parent below. 119 */ 120 p->p_flag &= ~(P_TRACED | P_PPWAIT); 121 p->p_flag |= P_WEXIT; 122 p->p_sigignore = ~0; 123 p->p_siglist = 0; 124 untimeout(realitexpire, (caddr_t)p); 125 126 /* 127 * Close open files and release open-file table. 128 * This may block! 129 */ 130 fdfree(p); 131 132 /* The next three chunks should probably be moved to vmspace_exit. */ 133 vm = p->p_vmspace; 134 #ifdef SYSVSHM 135 if (vm->vm_shm) 136 shmexit(p); 137 #endif 138 #ifdef SYSVSEM 139 semexit(p); 140 #endif 141 /* 142 * Release user portion of address space. 143 * This releases references to vnodes, 144 * which could cause I/O if the file has been unlinked. 145 * Need to do this early enough that we can still sleep. 146 * Can't free the entire vmspace as the kernel stack 147 * may be mapped within that space also. 148 */ 149 if (vm->vm_refcnt == 1) 150 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 151 VM_MAXUSER_ADDRESS); 152 153 if (SESS_LEADER(p)) { 154 register struct session *sp = p->p_session; 155 156 if (sp->s_ttyvp) { 157 /* 158 * Controlling process. 159 * Signal foreground pgrp, 160 * drain controlling terminal 161 * and revoke access to controlling terminal. 162 */ 163 if (sp->s_ttyp->t_session == sp) { 164 if (sp->s_ttyp->t_pgrp) 165 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 166 (void) ttywait(sp->s_ttyp); 167 /* 168 * The tty could have been revoked 169 * if we blocked. 170 */ 171 if (sp->s_ttyvp) 172 vgoneall(sp->s_ttyvp); 173 } 174 if (sp->s_ttyvp) 175 vrele(sp->s_ttyvp); 176 sp->s_ttyvp = NULL; 177 /* 178 * s_ttyp is not zero'd; we use this to indicate 179 * that the session once had a controlling terminal. 180 * (for logging and informational purposes) 181 */ 182 } 183 sp->s_leader = NULL; 184 } 185 fixjobc(p, p->p_pgrp, 0); 186 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 187 (void)acct_process(p); 188 #ifdef KTRACE 189 /* 190 * release trace file 191 */ 192 p->p_traceflag = 0; /* don't trace the vrele() */ 193 if (p->p_tracep) 194 vrele(p->p_tracep); 195 #endif 196 /* 197 * Remove proc from allproc queue and pidhash chain. 198 * Place onto zombproc. Unlink from parent's child list. 199 */ 200 LIST_REMOVE(p, p_list); 201 LIST_INSERT_HEAD(&zombproc, p, p_list); 202 p->p_stat = SZOMB; 203 204 LIST_REMOVE(p, p_hash); 205 206 q = p->p_children.lh_first; 207 if (q) /* only need this if any child is S_ZOMB */ 208 wakeup((caddr_t) initproc); 209 for (; q != 0; q = nq) { 210 nq = q->p_sibling.le_next; 211 proc_reparent(q, initproc); 212 /* 213 * Traced processes are killed 214 * since their existence means someone is screwing up. 215 */ 216 if (q->p_flag & P_TRACED) { 217 q->p_flag &= ~P_TRACED; 218 psignal(q, SIGKILL); 219 } 220 } 221 222 /* 223 * Save exit status and final rusage info, adding in child rusage 224 * info and self times. 225 */ 226 p->p_xstat = rv; 227 *p->p_ru = p->p_stats->p_ru; 228 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 229 ruadd(p->p_ru, &p->p_stats->p_cru); 230 231 /* 232 * Notify parent that we're gone. 233 */ 234 psignal(p->p_pptr, SIGCHLD); 235 wakeup((caddr_t)p->p_pptr); 236 /* 237 * Notify procfs debugger 238 */ 239 if (p->p_flag & P_FSTRACE) 240 wakeup((caddr_t)p); 241 #if defined(tahoe) 242 /* move this to cpu_exit */ 243 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 244 #endif 245 /* 246 * Clear curproc after we've done all operations 247 * that could block, and before tearing down the rest 248 * of the process state that might be used from clock, etc. 249 * Also, can't clear curproc while we're still runnable, 250 * as we're not on a run queue (we are current, just not 251 * a proper proc any longer!). 252 * 253 * Other substructures are freed from wait(). 254 */ 255 curproc = NULL; 256 limfree(p->p_limit); 257 258 /* 259 * Finally, call machine-dependent code to release the remaining 260 * resources including address space, the kernel stack and pcb. 261 * The address space is released by "vmspace_free(p->p_vmspace)"; 262 * This is machine-dependent, as we may have to change stacks 263 * or ensure that the current one isn't reallocated before we 264 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 265 * our execution (pun intended). 266 */ 267 cpu_exit(p); 268 } 269 270 int 271 sys_wait4(q, v, retval) 272 register struct proc *q; 273 void *v; 274 register_t *retval; 275 { 276 register struct sys_wait4_args /* { 277 syscallarg(int) pid; 278 syscallarg(int *) status; 279 syscallarg(int) options; 280 syscallarg(struct rusage *) rusage; 281 } */ *uap = v; 282 register int nfound; 283 register struct proc *p, *t; 284 int status, error; 285 286 #ifdef COMPAT_09 287 SCARG(uap, pid) = (short)SCARG(uap, pid); 288 #endif 289 290 if (SCARG(uap, pid) == 0) 291 SCARG(uap, pid) = -q->p_pgid; 292 #ifdef notyet 293 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG)) 294 return (EINVAL); 295 #endif 296 loop: 297 nfound = 0; 298 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 299 if (SCARG(uap, pid) != WAIT_ANY && 300 p->p_pid != SCARG(uap, pid) && 301 p->p_pgid != -SCARG(uap, pid)) 302 continue; 303 nfound++; 304 if (p->p_stat == SZOMB) { 305 retval[0] = p->p_pid; 306 307 if (SCARG(uap, status)) { 308 status = p->p_xstat; /* convert to int */ 309 if (error = copyout((caddr_t)&status, 310 (caddr_t)SCARG(uap, status), 311 sizeof(status))) 312 return (error); 313 } 314 if (SCARG(uap, rusage) && 315 (error = copyout((caddr_t)p->p_ru, 316 (caddr_t)SCARG(uap, rusage), 317 sizeof (struct rusage)))) 318 return (error); 319 /* 320 * If we got the child via a ptrace 'attach', 321 * we need to give it back to the old parent. 322 */ 323 if (p->p_oppid && (t = pfind(p->p_oppid))) { 324 p->p_oppid = 0; 325 proc_reparent(p, t); 326 psignal(t, SIGCHLD); 327 wakeup((caddr_t)t); 328 return (0); 329 } 330 p->p_xstat = 0; 331 ruadd(&q->p_stats->p_cru, p->p_ru); 332 FREE(p->p_ru, M_ZOMBIE); 333 334 /* 335 * Finally finished with old proc entry. 336 * Unlink it from its process group and free it. 337 */ 338 leavepgrp(p); 339 LIST_REMOVE(p, p_list); /* off zombproc */ 340 LIST_REMOVE(p, p_sibling); 341 342 /* 343 * Decrement the count of procs running with this uid. 344 */ 345 (void)chgproccnt(p->p_cred->p_ruid, -1); 346 347 /* 348 * Free up credentials. 349 */ 350 if (--p->p_cred->p_refcnt == 0) { 351 crfree(p->p_cred->pc_ucred); 352 FREE(p->p_cred, M_SUBPROC); 353 } 354 355 /* 356 * Release reference to text vnode 357 */ 358 if (p->p_textvp) 359 vrele(p->p_textvp); 360 361 /* 362 * Give machine-dependent layer a chance 363 * to free anything that cpu_exit couldn't 364 * release while still running in process context. 365 */ 366 cpu_wait(p); 367 FREE(p, M_PROC); 368 nprocs--; 369 return (0); 370 } 371 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 372 (p->p_flag & P_TRACED || SCARG(uap, options) & WUNTRACED)) { 373 p->p_flag |= P_WAITED; 374 retval[0] = p->p_pid; 375 376 if (SCARG(uap, status)) { 377 status = W_STOPCODE(p->p_xstat); 378 error = copyout((caddr_t)&status, 379 (caddr_t)SCARG(uap, status), 380 sizeof(status)); 381 } else 382 error = 0; 383 return (error); 384 } 385 } 386 if (nfound == 0) 387 return (ECHILD); 388 if (SCARG(uap, options) & WNOHANG) { 389 retval[0] = 0; 390 return (0); 391 } 392 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 393 return (error); 394 goto loop; 395 } 396 397 /* 398 * make process 'parent' the new parent of process 'child'. 399 */ 400 void 401 proc_reparent(child, parent) 402 register struct proc *child; 403 register struct proc *parent; 404 { 405 406 if (child->p_pptr == parent) 407 return; 408 409 LIST_REMOVE(child, p_sibling); 410 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 411 child->p_pptr = parent; 412 } 413
Indexes created Mon Sep 22 13:09:51 GMT 2025