kern_exit.c revision 1.30
1 /* $NetBSD: kern_exit.c,v 1.30 1995/06/24 20:33:59 christos 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 __dead void cpu_exit __P((struct proc *)) __attribute__((noreturn)); 72 __dead void exit1 __P((struct proc *, int)) __attribute__((noreturn)); 73 74 /* 75 * exit -- 76 * Death of process. 77 */ 78 __dead void 79 exit(p, uap, retval) 80 struct proc *p; 81 struct exit_args /* { 82 syscallarg(int) rval; 83 } */ *uap; 84 int *retval; 85 { 86 87 exit1(p, W_EXITCODE(SCARG(uap, rval), 0)); 88 /* NOTREACHED */ 89 } 90 91 /* 92 * Exit: deallocate address space and other resources, change proc state 93 * to zombie, and unlink proc from allproc and parent's lists. Save exit 94 * status and rusage for wait(). Check for child processes and orphan them. 95 */ 96 __dead void 97 exit1(p, rv) 98 register struct proc *p; 99 int rv; 100 { 101 register struct proc *q, *nq; 102 register struct vmspace *vm; 103 104 if (p->p_pid == 1) 105 panic("init died (signal %d, exit %d)", 106 WTERMSIG(rv), WEXITSTATUS(rv)); 107 #ifdef PGINPROF 108 vmsizmon(); 109 #endif 110 if (p->p_flag & P_PROFIL) 111 stopprofclock(p); 112 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 113 M_ZOMBIE, M_WAITOK); 114 /* 115 * If parent is waiting for us to exit or exec, 116 * P_PPWAIT is set; we will wakeup the parent below. 117 */ 118 p->p_flag &= ~(P_TRACED | P_PPWAIT); 119 p->p_flag |= P_WEXIT; 120 p->p_sigignore = ~0; 121 p->p_siglist = 0; 122 untimeout(realitexpire, (caddr_t)p); 123 124 /* 125 * Close open files and release open-file table. 126 * This may block! 127 */ 128 fdfree(p); 129 130 /* The next three chunks should probably be moved to vmspace_exit. */ 131 vm = p->p_vmspace; 132 #ifdef SYSVSHM 133 if (vm->vm_shm) 134 shmexit(p); 135 #endif 136 #ifdef SYSVSEM 137 semexit(p); 138 #endif 139 /* 140 * Release user portion of address space. 141 * This releases references to vnodes, 142 * which could cause I/O if the file has been unlinked. 143 * Need to do this early enough that we can still sleep. 144 * Can't free the entire vmspace as the kernel stack 145 * may be mapped within that space also. 146 */ 147 if (vm->vm_refcnt == 1) 148 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 149 VM_MAXUSER_ADDRESS); 150 151 if (SESS_LEADER(p)) { 152 register struct session *sp = p->p_session; 153 154 if (sp->s_ttyvp) { 155 /* 156 * Controlling process. 157 * Signal foreground pgrp, 158 * drain controlling terminal 159 * and revoke access to controlling terminal. 160 */ 161 if (sp->s_ttyp->t_session == sp) { 162 if (sp->s_ttyp->t_pgrp) 163 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 164 (void) ttywait(sp->s_ttyp); 165 /* 166 * The tty could have been revoked 167 * if we blocked. 168 */ 169 if (sp->s_ttyvp) 170 vgoneall(sp->s_ttyvp); 171 } 172 if (sp->s_ttyvp) 173 vrele(sp->s_ttyvp); 174 sp->s_ttyvp = NULL; 175 /* 176 * s_ttyp is not zero'd; we use this to indicate 177 * that the session once had a controlling terminal. 178 * (for logging and informational purposes) 179 */ 180 } 181 sp->s_leader = NULL; 182 } 183 fixjobc(p, p->p_pgrp, 0); 184 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 185 (void)acct_process(p); 186 #ifdef KTRACE 187 /* 188 * release trace file 189 */ 190 p->p_traceflag = 0; /* don't trace the vrele() */ 191 if (p->p_tracep) 192 vrele(p->p_tracep); 193 #endif 194 /* 195 * Remove proc from allproc queue and pidhash chain. 196 * Place onto zombproc. Unlink from parent's child list. 197 */ 198 LIST_REMOVE(p, p_list); 199 LIST_INSERT_HEAD(&zombproc, p, p_list); 200 p->p_stat = SZOMB; 201 202 LIST_REMOVE(p, p_hash); 203 204 q = p->p_children.lh_first; 205 if (q) /* only need this if any child is S_ZOMB */ 206 wakeup((caddr_t) initproc); 207 for (; q != 0; q = nq) { 208 nq = q->p_sibling.le_next; 209 proc_reparent(q, initproc); 210 /* 211 * Traced processes are killed 212 * since their existence means someone is screwing up. 213 */ 214 if (q->p_flag & P_TRACED) { 215 q->p_flag &= ~P_TRACED; 216 psignal(q, SIGKILL); 217 } 218 } 219 220 /* 221 * Save exit status and final rusage info, adding in child rusage 222 * info and self times. 223 */ 224 p->p_xstat = rv; 225 *p->p_ru = p->p_stats->p_ru; 226 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 227 ruadd(p->p_ru, &p->p_stats->p_cru); 228 229 /* 230 * Notify parent that we're gone. 231 */ 232 psignal(p->p_pptr, SIGCHLD); 233 wakeup((caddr_t)p->p_pptr); 234 /* 235 * Notify procfs debugger 236 */ 237 if (p->p_flag & P_FSTRACE) 238 wakeup((caddr_t)p); 239 #if defined(tahoe) 240 /* move this to cpu_exit */ 241 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 242 #endif 243 /* 244 * Clear curproc after we've done all operations 245 * that could block, and before tearing down the rest 246 * of the process state that might be used from clock, etc. 247 * Also, can't clear curproc while we're still runnable, 248 * as we're not on a run queue (we are current, just not 249 * a proper proc any longer!). 250 * 251 * Other substructures are freed from wait(). 252 */ 253 curproc = NULL; 254 if (--p->p_limit->p_refcnt == 0) 255 FREE(p->p_limit, M_SUBPROC); 256 257 /* 258 * Finally, call machine-dependent code to release the remaining 259 * resources including address space, the kernel stack and pcb. 260 * The address space is released by "vmspace_free(p->p_vmspace)"; 261 * This is machine-dependent, as we may have to change stacks 262 * or ensure that the current one isn't reallocated before we 263 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 264 * our execution (pun intended). 265 */ 266 cpu_exit(p); 267 } 268 269 int 270 wait4(q, uap, retval, compat) 271 register struct proc *q; 272 register struct wait4_args /* { 273 syscallarg(int) pid; 274 syscallarg(int *) status; 275 syscallarg(int) options; 276 syscallarg(struct rusage *) rusage; 277 } */ *uap; 278 register_t *retval; 279 { 280 register int nfound; 281 register struct proc *p, *t; 282 int status, error; 283 284 #ifdef COMPAT_09 285 SCARG(uap, pid) = (short)SCARG(uap, pid); 286 #endif 287 288 if (SCARG(uap, pid) == 0) 289 SCARG(uap, pid) = -q->p_pgid; 290 #ifdef notyet 291 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG)) 292 return (EINVAL); 293 #endif 294 loop: 295 nfound = 0; 296 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 297 if (SCARG(uap, pid) != WAIT_ANY && 298 p->p_pid != SCARG(uap, pid) && 299 p->p_pgid != -SCARG(uap, pid)) 300 continue; 301 nfound++; 302 if (p->p_stat == SZOMB) { 303 retval[0] = p->p_pid; 304 305 if (SCARG(uap, status)) { 306 status = p->p_xstat; /* convert to int */ 307 if (error = copyout((caddr_t)&status, 308 (caddr_t)SCARG(uap, status), 309 sizeof(status))) 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 a ptrace 'attach', 319 * we need to give it back to the old parent. 320 */ 321 if (p->p_oppid && (t = pfind(p->p_oppid))) { 322 p->p_oppid = 0; 323 proc_reparent(p, t); 324 psignal(t, SIGCHLD); 325 wakeup((caddr_t)t); 326 return (0); 327 } 328 p->p_xstat = 0; 329 ruadd(&q->p_stats->p_cru, p->p_ru); 330 FREE(p->p_ru, M_ZOMBIE); 331 332 /* 333 * Decrement the count of procs running with this uid. 334 */ 335 (void)chgproccnt(p->p_cred->p_ruid, -1); 336 337 /* 338 * Free up credentials. 339 */ 340 if (--p->p_cred->p_refcnt == 0) { 341 crfree(p->p_cred->pc_ucred); 342 FREE(p->p_cred, M_SUBPROC); 343 } 344 345 /* 346 * Release reference to text vnode 347 */ 348 if (p->p_textvp) 349 vrele(p->p_textvp); 350 351 /* 352 * Finally finished with old proc entry. 353 * Unlink it from its process group and free it. 354 */ 355 leavepgrp(p); 356 LIST_REMOVE(p, p_list); /* off zombproc */ 357 LIST_REMOVE(p, p_sibling); 358 359 /* 360 * Give machine-dependent layer a chance 361 * to free anything that cpu_exit couldn't 362 * release while still running in process context. 363 */ 364 cpu_wait(p); 365 FREE(p, M_PROC); 366 nprocs--; 367 return (0); 368 } 369 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 370 (p->p_flag & P_TRACED || SCARG(uap, options) & WUNTRACED)) { 371 p->p_flag |= P_WAITED; 372 retval[0] = p->p_pid; 373 374 if (SCARG(uap, status)) { 375 status = W_STOPCODE(p->p_xstat); 376 error = copyout((caddr_t)&status, 377 (caddr_t)SCARG(uap, status), 378 sizeof(status)); 379 } else 380 error = 0; 381 return (error); 382 } 383 } 384 if (nfound == 0) 385 return (ECHILD); 386 if (SCARG(uap, options) & WNOHANG) { 387 retval[0] = 0; 388 return (0); 389 } 390 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 391 return (error); 392 goto loop; 393 } 394 395 /* 396 * make process 'parent' the new parent of process 'child'. 397 */ 398 void 399 proc_reparent(child, parent) 400 register struct proc *child; 401 register struct proc *parent; 402 { 403 404 if (child->p_pptr == parent) 405 return; 406 407 LIST_REMOVE(child, p_sibling); 408 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 409 child->p_pptr = parent; 410 } 411
Indexes created Tue Sep 23 07:09:52 GMT 2025