1 /* $NetBSD: kern_exit.c,v 1.25 1994/08/30 03:05:33 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 62 #include <machine/cpu.h> 63 #ifdef COMPAT_43 64 #include <machine/reg.h> 65 #include <machine/psl.h> 66 #endif 67 68 #include <vm/vm.h> 69 #include <vm/vm_kern.h> 70 71 __dead void cpu_exit __P((struct proc *)); 72 __dead void exit1 __P((struct proc *, int)); 73 74 /* 75 * exit -- 76 * Death of process. 77 */ 78 struct exit_args { 79 int rval; 80 }; 81 __dead void 82 exit(p, uap, retval) 83 struct proc *p; 84 struct exit_args *uap; 85 int *retval; 86 { 87 88 exit1(p, W_EXITCODE(uap->rval, 0)); 89 /* NOTREACHED */ 90 } 91 92 /* 93 * Exit: deallocate address space and other resources, change proc state 94 * to zombie, and unlink proc from allproc and parent's lists. Save exit 95 * status and rusage for wait(). Check for child processes and orphan them. 96 */ 97 __dead void 98 exit1(p, rv) 99 register struct proc *p; 100 int rv; 101 { 102 register struct proc *q, *nq; 103 register struct proc **pp; 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 LIST_REMOVE(q, p_sibling); 212 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling); 213 q->p_pptr = initproc; 214 /* 215 * Traced processes are killed 216 * since their existence means someone is screwing up. 217 */ 218 if (q->p_flag & P_TRACED) { 219 q->p_flag &= ~P_TRACED; 220 psignal(q, SIGKILL); 221 } 222 } 223 224 /* 225 * Save exit status and final rusage info, adding in child rusage 226 * info and self times. 227 */ 228 p->p_xstat = rv; 229 *p->p_ru = p->p_stats->p_ru; 230 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 231 ruadd(p->p_ru, &p->p_stats->p_cru); 232 233 /* 234 * Notify parent that we're gone. 235 */ 236 psignal(p->p_pptr, SIGCHLD); 237 wakeup((caddr_t)p->p_pptr); 238 /* 239 * Notify procfs debugger 240 */ 241 if (p->p_flag & P_FSTRACE) 242 wakeup((caddr_t)p); 243 #if defined(tahoe) 244 /* move this to cpu_exit */ 245 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 246 #endif 247 /* 248 * Clear curproc after we've done all operations 249 * that could block, and before tearing down the rest 250 * of the process state that might be used from clock, etc. 251 * Also, can't clear curproc while we're still runnable, 252 * as we're not on a run queue (we are current, just not 253 * a proper proc any longer!). 254 * 255 * Other substructures are freed from wait(). 256 */ 257 curproc = NULL; 258 if (--p->p_limit->p_refcnt == 0) 259 FREE(p->p_limit, M_SUBPROC); 260 261 /* 262 * Finally, call machine-dependent code to release the remaining 263 * resources including address space, the kernel stack and pcb. 264 * The address space is released by "vmspace_free(p->p_vmspace)"; 265 * This is machine-dependent, as we may have to change stacks 266 * or ensure that the current one isn't reallocated before we 267 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 268 * our execution (pun intended). 269 */ 270 cpu_exit(p); 271 } 272 273 struct wait_args { 274 int pid; 275 int *status; 276 int options; 277 struct rusage *rusage; 278 #ifdef COMPAT_43 279 int compat; /* pseudo */ 280 #endif 281 }; 282 283 #ifdef COMPAT_43 284 #ifdef m68k 285 #include <machine/frame.h> 286 #define GETPS(rp) ((struct frame *)(rp))->f_sr 287 #else 288 #define GETPS(rp) (rp)[PS] 289 #endif 290 291 owait(p, uap, retval) 292 struct proc *p; 293 register struct wait_args *uap; 294 int *retval; 295 { 296 297 #ifdef PSL_ALLCC 298 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 299 uap->options = 0; 300 uap->rusage = NULL; 301 } else { 302 uap->options = p->p_md.md_regs[R0]; 303 uap->rusage = (struct rusage *)p->p_md.md_regs[R1]; 304 } 305 #else 306 uap->options = 0; 307 uap->rusage = NULL; 308 #endif 309 uap->pid = WAIT_ANY; 310 uap->status = NULL; 311 uap->compat = 1; 312 return (wait1(p, uap, retval)); 313 } 314 315 wait4(p, uap, retval) 316 struct proc *p; 317 struct wait_args *uap; 318 int *retval; 319 { 320 321 uap->compat = 0; 322 return (wait1(p, uap, retval)); 323 } 324 #else 325 #define wait1 wait4 326 #endif 327 328 int 329 wait1(q, uap, retval) 330 register struct proc *q; 331 register struct wait_args *uap; 332 int retval[]; 333 { 334 register int nfound; 335 register struct proc *p, *t; 336 int status, error; 337 338 #ifdef COMPAT_09 339 uap->pid = (short) uap->pid; 340 #endif 341 342 if (uap->pid == 0) 343 uap->pid = -q->p_pgid; 344 #ifdef notyet 345 if (uap->options &~ (WUNTRACED|WNOHANG)) 346 return (EINVAL); 347 #endif 348 loop: 349 nfound = 0; 350 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 351 if (uap->pid != WAIT_ANY && 352 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 353 continue; 354 nfound++; 355 if (p->p_stat == SZOMB) { 356 retval[0] = p->p_pid; 357 #ifdef COMPAT_43 358 if (uap->compat) 359 retval[1] = p->p_xstat; 360 else 361 #endif 362 if (uap->status) { 363 status = p->p_xstat; /* convert to int */ 364 if (error = copyout((caddr_t)&status, 365 (caddr_t)uap->status, sizeof(status))) 366 return (error); 367 } 368 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 369 (caddr_t)uap->rusage, sizeof (struct rusage)))) 370 return (error); 371 /* 372 * If we got the child via a ptrace 'attach', 373 * we need to give it back to the old parent. 374 */ 375 if (p->p_oppid && (t = pfind(p->p_oppid))) { 376 p->p_oppid = 0; 377 proc_reparent(p, t); 378 psignal(t, SIGCHLD); 379 wakeup((caddr_t)t); 380 return (0); 381 } 382 p->p_xstat = 0; 383 ruadd(&q->p_stats->p_cru, p->p_ru); 384 FREE(p->p_ru, M_ZOMBIE); 385 386 /* 387 * Decrement the count of procs running with this uid. 388 */ 389 (void)chgproccnt(p->p_cred->p_ruid, -1); 390 391 /* 392 * Free up credentials. 393 */ 394 if (--p->p_cred->p_refcnt == 0) { 395 crfree(p->p_cred->pc_ucred); 396 FREE(p->p_cred, M_SUBPROC); 397 } 398 399 /* 400 * Release reference to text vnode 401 */ 402 if (p->p_textvp) 403 vrele(p->p_textvp); 404 405 /* 406 * Finally finished with old proc entry. 407 * Unlink it from its process group and free it. 408 */ 409 leavepgrp(p); 410 LIST_REMOVE(p, p_list); /* off zombproc */ 411 LIST_REMOVE(p, p_sibling); 412 413 /* 414 * Give machine-dependent layer a chance 415 * to free anything that cpu_exit couldn't 416 * release while still running in process context. 417 */ 418 cpu_wait(p); 419 FREE(p, M_PROC); 420 nprocs--; 421 return (0); 422 } 423 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 424 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 425 p->p_flag |= P_WAITED; 426 retval[0] = p->p_pid; 427 #ifdef COMPAT_43 428 if (uap->compat) { 429 retval[1] = W_STOPCODE(p->p_xstat); 430 error = 0; 431 } else 432 #endif 433 if (uap->status) { 434 status = W_STOPCODE(p->p_xstat); 435 error = copyout((caddr_t)&status, 436 (caddr_t)uap->status, sizeof(status)); 437 } else 438 error = 0; 439 return (error); 440 } 441 } 442 if (nfound == 0) 443 return (ECHILD); 444 if (uap->options & WNOHANG) { 445 retval[0] = 0; 446 return (0); 447 } 448 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 449 return (error); 450 goto loop; 451 } 452 453 /* 454 * make process 'parent' the new parent of process 'child'. 455 */ 456 void 457 proc_reparent(child, parent) 458 register struct proc *child; 459 register struct proc *parent; 460 { 461 462 if (child->p_pptr == parent) 463 return; 464 465 LIST_REMOVE(child, p_sibling); 466 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 467 child->p_pptr = parent; 468 } 469