kern_exit.c revision 1.29
1 /* $NetBSD: kern_exit.c,v 1.29 1994/12/24 15:07:26 cgd 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 #ifdef COMPAT_43 68 #include <machine/reg.h> 69 #include <machine/psl.h> 70 #endif 71 72 #include <vm/vm.h> 73 #include <vm/vm_kern.h> 74 75 __dead void cpu_exit __P((struct proc *)) __attribute__((noreturn)); 76 __dead void exit1 __P((struct proc *, int)) __attribute__((noreturn)); 77 78 /* 79 * exit -- 80 * Death of process. 81 */ 82 __dead void 83 exit(p, uap, retval) 84 struct proc *p; 85 struct exit_args /* { 86 syscallarg(int) rval; 87 } */ *uap; 88 int *retval; 89 { 90 91 exit1(p, W_EXITCODE(SCARG(uap, rval), 0)); 92 /* NOTREACHED */ 93 } 94 95 /* 96 * Exit: deallocate address space and other resources, change proc state 97 * to zombie, and unlink proc from allproc and parent's lists. Save exit 98 * status and rusage for wait(). Check for child processes and orphan them. 99 */ 100 __dead void 101 exit1(p, rv) 102 register struct proc *p; 103 int rv; 104 { 105 register struct proc *q, *nq; 106 register struct vmspace *vm; 107 108 if (p->p_pid == 1) 109 panic("init died (signal %d, exit %d)", 110 WTERMSIG(rv), WEXITSTATUS(rv)); 111 #ifdef PGINPROF 112 vmsizmon(); 113 #endif 114 if (p->p_flag & P_PROFIL) 115 stopprofclock(p); 116 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 117 M_ZOMBIE, M_WAITOK); 118 /* 119 * If parent is waiting for us to exit or exec, 120 * P_PPWAIT is set; we will wakeup the parent below. 121 */ 122 p->p_flag &= ~(P_TRACED | P_PPWAIT); 123 p->p_flag |= P_WEXIT; 124 p->p_sigignore = ~0; 125 p->p_siglist = 0; 126 untimeout(realitexpire, (caddr_t)p); 127 128 /* 129 * Close open files and release open-file table. 130 * This may block! 131 */ 132 fdfree(p); 133 134 /* The next three chunks should probably be moved to vmspace_exit. */ 135 vm = p->p_vmspace; 136 #ifdef SYSVSHM 137 if (vm->vm_shm) 138 shmexit(p); 139 #endif 140 #ifdef SYSVSEM 141 semexit(p); 142 #endif 143 /* 144 * Release user portion of address space. 145 * This releases references to vnodes, 146 * which could cause I/O if the file has been unlinked. 147 * Need to do this early enough that we can still sleep. 148 * Can't free the entire vmspace as the kernel stack 149 * may be mapped within that space also. 150 */ 151 if (vm->vm_refcnt == 1) 152 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 153 VM_MAXUSER_ADDRESS); 154 155 if (SESS_LEADER(p)) { 156 register struct session *sp = p->p_session; 157 158 if (sp->s_ttyvp) { 159 /* 160 * Controlling process. 161 * Signal foreground pgrp, 162 * drain controlling terminal 163 * and revoke access to controlling terminal. 164 */ 165 if (sp->s_ttyp->t_session == sp) { 166 if (sp->s_ttyp->t_pgrp) 167 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 168 (void) ttywait(sp->s_ttyp); 169 /* 170 * The tty could have been revoked 171 * if we blocked. 172 */ 173 if (sp->s_ttyvp) 174 vgoneall(sp->s_ttyvp); 175 } 176 if (sp->s_ttyvp) 177 vrele(sp->s_ttyvp); 178 sp->s_ttyvp = NULL; 179 /* 180 * s_ttyp is not zero'd; we use this to indicate 181 * that the session once had a controlling terminal. 182 * (for logging and informational purposes) 183 */ 184 } 185 sp->s_leader = NULL; 186 } 187 fixjobc(p, p->p_pgrp, 0); 188 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 189 (void)acct_process(p); 190 #ifdef KTRACE 191 /* 192 * release trace file 193 */ 194 p->p_traceflag = 0; /* don't trace the vrele() */ 195 if (p->p_tracep) 196 vrele(p->p_tracep); 197 #endif 198 /* 199 * Remove proc from allproc queue and pidhash chain. 200 * Place onto zombproc. Unlink from parent's child list. 201 */ 202 LIST_REMOVE(p, p_list); 203 LIST_INSERT_HEAD(&zombproc, p, p_list); 204 p->p_stat = SZOMB; 205 206 LIST_REMOVE(p, p_hash); 207 208 q = p->p_children.lh_first; 209 if (q) /* only need this if any child is S_ZOMB */ 210 wakeup((caddr_t) initproc); 211 for (; q != 0; q = nq) { 212 nq = q->p_sibling.le_next; 213 proc_reparent(q, 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 #ifdef COMPAT_43 274 #ifdef m68k 275 #include <machine/frame.h> 276 #define GETPS(rp) ((struct frame *)(rp))->f_sr 277 #else 278 #define GETPS(rp) (rp)[PS] 279 #endif 280 281 int 282 compat_43_wait(p, uap, retval) 283 struct proc *p; 284 void *uap; 285 int *retval; 286 { 287 struct wait4_args /* { 288 syscallarg(int) pid; 289 syscallarg(int *) status; 290 syscallarg(int) options; 291 syscallarg(struct rusage *) rusage; 292 } */ a; 293 294 #ifdef PSL_ALLCC 295 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 296 SCARG(&a, options) = 0; 297 SCARG(&a, rusage) = NULL; 298 } else { 299 SCARG(&a, options) = p->p_md.md_regs[R0]; 300 SCARG(&a, rusage) = (struct rusage *)p->p_md.md_regs[R1]; 301 } 302 #else 303 SCARG(&a, options) = 0; 304 SCARG(&a, rusage) = NULL; 305 #endif 306 SCARG(&a, pid) = WAIT_ANY; 307 SCARG(&a, status) = NULL; 308 return (wait1(p, &a, retval, 1)); 309 } 310 311 int 312 wait4(p, uap, retval) 313 struct proc *p; 314 struct wait4_args /* { 315 syscallarg(int) pid; 316 syscallarg(int *) status; 317 syscallarg(int) options; 318 syscallarg(struct rusage *) rusage; 319 } */ *uap; 320 int *retval; 321 { 322 323 return (wait1(p, uap, retval, 0)); 324 } 325 #else 326 #define wait1 wait4 327 #endif 328 329 int 330 wait1(q, uap, retval, compat) 331 register struct proc *q; 332 register struct wait4_args /* { 333 syscallarg(int) pid; 334 syscallarg(int *) status; 335 syscallarg(int) options; 336 syscallarg(struct rusage *) rusage; 337 } */ *uap; 338 register_t *retval; 339 #ifdef COMPAT_43 340 int compat; 341 #endif 342 { 343 register int nfound; 344 register struct proc *p, *t; 345 int status, error; 346 347 #ifdef COMPAT_09 348 SCARG(uap, pid) = (short)SCARG(uap, pid); 349 #endif 350 351 if (SCARG(uap, pid) == 0) 352 SCARG(uap, pid) = -q->p_pgid; 353 #ifdef notyet 354 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG)) 355 return (EINVAL); 356 #endif 357 loop: 358 nfound = 0; 359 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 360 if (SCARG(uap, pid) != WAIT_ANY && 361 p->p_pid != SCARG(uap, pid) && 362 p->p_pgid != -SCARG(uap, pid)) 363 continue; 364 nfound++; 365 if (p->p_stat == SZOMB) { 366 retval[0] = p->p_pid; 367 #ifdef COMPAT_43 368 if (compat) 369 retval[1] = p->p_xstat; 370 else 371 #endif 372 if (SCARG(uap, status)) { 373 status = p->p_xstat; /* convert to int */ 374 if (error = copyout((caddr_t)&status, 375 (caddr_t)SCARG(uap, status), 376 sizeof(status))) 377 return (error); 378 } 379 if (SCARG(uap, rusage) && 380 (error = copyout((caddr_t)p->p_ru, 381 (caddr_t)SCARG(uap, rusage), 382 sizeof (struct rusage)))) 383 return (error); 384 /* 385 * If we got the child via a ptrace 'attach', 386 * we need to give it back to the old parent. 387 */ 388 if (p->p_oppid && (t = pfind(p->p_oppid))) { 389 p->p_oppid = 0; 390 proc_reparent(p, t); 391 psignal(t, SIGCHLD); 392 wakeup((caddr_t)t); 393 return (0); 394 } 395 p->p_xstat = 0; 396 ruadd(&q->p_stats->p_cru, p->p_ru); 397 FREE(p->p_ru, M_ZOMBIE); 398 399 /* 400 * Decrement the count of procs running with this uid. 401 */ 402 (void)chgproccnt(p->p_cred->p_ruid, -1); 403 404 /* 405 * Free up credentials. 406 */ 407 if (--p->p_cred->p_refcnt == 0) { 408 crfree(p->p_cred->pc_ucred); 409 FREE(p->p_cred, M_SUBPROC); 410 } 411 412 /* 413 * Release reference to text vnode 414 */ 415 if (p->p_textvp) 416 vrele(p->p_textvp); 417 418 /* 419 * Finally finished with old proc entry. 420 * Unlink it from its process group and free it. 421 */ 422 leavepgrp(p); 423 LIST_REMOVE(p, p_list); /* off zombproc */ 424 LIST_REMOVE(p, p_sibling); 425 426 /* 427 * Give machine-dependent layer a chance 428 * to free anything that cpu_exit couldn't 429 * release while still running in process context. 430 */ 431 cpu_wait(p); 432 FREE(p, M_PROC); 433 nprocs--; 434 return (0); 435 } 436 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 437 (p->p_flag & P_TRACED || SCARG(uap, options) & WUNTRACED)) { 438 p->p_flag |= P_WAITED; 439 retval[0] = p->p_pid; 440 #ifdef COMPAT_43 441 if (compat) { 442 retval[1] = W_STOPCODE(p->p_xstat); 443 error = 0; 444 } else 445 #endif 446 if (SCARG(uap, status)) { 447 status = W_STOPCODE(p->p_xstat); 448 error = copyout((caddr_t)&status, 449 (caddr_t)SCARG(uap, status), 450 sizeof(status)); 451 } else 452 error = 0; 453 return (error); 454 } 455 } 456 if (nfound == 0) 457 return (ECHILD); 458 if (SCARG(uap, options) & WNOHANG) { 459 retval[0] = 0; 460 return (0); 461 } 462 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 463 return (error); 464 goto loop; 465 } 466 467 /* 468 * make process 'parent' the new parent of process 'child'. 469 */ 470 void 471 proc_reparent(child, parent) 472 register struct proc *child; 473 register struct proc *parent; 474 { 475 476 if (child->p_pptr == parent) 477 return; 478 479 LIST_REMOVE(child, p_sibling); 480 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 481 child->p_pptr = parent; 482 } 483
Indexes created Tue Sep 23 07:09:52 GMT 2025