1 /* $NetBSD: kern_exit.c,v 1.49 1998/03/01 02:22:28 fvdl 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 8.10 (Berkeley) 2/23/95 41 */ 42 43 #include "opt_uvm.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/map.h> 48 #include <sys/ioctl.h> 49 #include <sys/proc.h> 50 #include <sys/tty.h> 51 #include <sys/time.h> 52 #include <sys/resource.h> 53 #include <sys/kernel.h> 54 #include <sys/proc.h> 55 #include <sys/buf.h> 56 #include <sys/wait.h> 57 #include <sys/file.h> 58 #include <sys/vnode.h> 59 #include <sys/syslog.h> 60 #include <sys/malloc.h> 61 #include <sys/resourcevar.h> 62 #include <sys/ptrace.h> 63 #include <sys/acct.h> 64 #include <sys/filedesc.h> 65 #include <sys/signalvar.h> 66 #ifdef SYSVSHM 67 #include <sys/shm.h> 68 #endif 69 #ifdef SYSVSEM 70 #include <sys/sem.h> 71 #endif 72 73 #include <sys/mount.h> 74 #include <sys/syscallargs.h> 75 76 #include <machine/cpu.h> 77 78 #include <vm/vm.h> 79 #include <vm/vm_kern.h> 80 81 #if defined(UVM) 82 #include <uvm/uvm_extern.h> 83 #endif 84 85 /* 86 * exit -- 87 * Death of process. 88 */ 89 int 90 sys_exit(p, v, retval) 91 struct proc *p; 92 void *v; 93 register_t *retval; 94 { 95 struct sys_exit_args /* { 96 syscallarg(int) rval; 97 } */ *uap = v; 98 99 exit1(p, W_EXITCODE(SCARG(uap, rval), 0)); 100 /* NOTREACHED */ 101 return (0); 102 } 103 104 /* 105 * Exit: deallocate address space and other resources, change proc state 106 * to zombie, and unlink proc from allproc and parent's lists. Save exit 107 * status and rusage for wait(). Check for child processes and orphan them. 108 */ 109 void 110 exit1(p, rv) 111 register struct proc *p; 112 int rv; 113 { 114 register struct proc *q, *nq; 115 register struct vmspace *vm; 116 117 if (p->p_pid == 1) 118 panic("init died (signal %d, exit %d)", 119 WTERMSIG(rv), WEXITSTATUS(rv)); 120 #ifdef PGINPROF 121 vmsizmon(); 122 #endif 123 if (p->p_flag & P_PROFIL) 124 stopprofclock(p); 125 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 126 M_ZOMBIE, M_WAITOK); 127 /* 128 * If parent is waiting for us to exit or exec, P_PPWAIT is set; we 129 * wake up the parent early to avoid deadlock. 130 */ 131 p->p_flag |= P_WEXIT; 132 if (p->p_flag & P_PPWAIT) { 133 p->p_flag &= ~P_PPWAIT; 134 wakeup((caddr_t)p->p_pptr); 135 } 136 p->p_sigignore = ~0; 137 p->p_siglist = 0; 138 untimeout(realitexpire, (caddr_t)p); 139 140 /* 141 * Close open files and release open-file table. 142 * This may block! 143 */ 144 fdfree(p); 145 146 /* The next three chunks should probably be moved to vmspace_exit. */ 147 vm = p->p_vmspace; 148 #ifdef SYSVSHM 149 if (vm->vm_shm && vm->vm_refcnt == 1) 150 shmexit(vm); 151 #endif 152 #ifdef SYSVSEM 153 semexit(p); 154 #endif 155 /* 156 * Release user portion of address space. 157 * This releases references to vnodes, 158 * which could cause I/O if the file has been unlinked. 159 * Need to do this early enough that we can still sleep. 160 * Can't free the entire vmspace as the kernel stack 161 * may be mapped within that space also. 162 */ 163 #if defined(UVM) 164 if (vm->vm_refcnt == 1) 165 (void) uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 166 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 167 #else 168 if (vm->vm_refcnt == 1) 169 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 170 VM_MAXUSER_ADDRESS); 171 #endif 172 173 if (SESS_LEADER(p)) { 174 register struct session *sp = p->p_session; 175 176 if (sp->s_ttyvp) { 177 /* 178 * Controlling process. 179 * Signal foreground pgrp, 180 * drain controlling terminal 181 * and revoke access to controlling terminal. 182 */ 183 if (sp->s_ttyp->t_session == sp) { 184 if (sp->s_ttyp->t_pgrp) 185 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 186 (void) ttywait(sp->s_ttyp); 187 /* 188 * The tty could have been revoked 189 * if we blocked. 190 */ 191 if (sp->s_ttyvp) 192 VOP_REVOKE(sp->s_ttyvp, REVOKEALL); 193 } 194 if (sp->s_ttyvp) 195 vrele(sp->s_ttyvp); 196 sp->s_ttyvp = NULL; 197 /* 198 * s_ttyp is not zero'd; we use this to indicate 199 * that the session once had a controlling terminal. 200 * (for logging and informational purposes) 201 */ 202 } 203 sp->s_leader = NULL; 204 } 205 fixjobc(p, p->p_pgrp, 0); 206 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 207 (void)acct_process(p); 208 #ifdef KTRACE 209 /* 210 * release trace file 211 */ 212 p->p_traceflag = 0; /* don't trace the vrele() */ 213 if (p->p_tracep) 214 vrele(p->p_tracep); 215 #endif 216 /* 217 * Remove proc from allproc queue and pidhash chain. 218 * Place onto zombproc. Unlink from parent's child list. 219 */ 220 LIST_REMOVE(p, p_list); 221 LIST_INSERT_HEAD(&zombproc, p, p_list); 222 p->p_stat = SZOMB; 223 224 LIST_REMOVE(p, p_hash); 225 226 q = p->p_children.lh_first; 227 if (q) /* only need this if any child is S_ZOMB */ 228 wakeup((caddr_t)initproc); 229 for (; q != 0; q = nq) { 230 nq = q->p_sibling.le_next; 231 proc_reparent(q, initproc); 232 /* 233 * Traced processes are killed 234 * since their existence means someone is screwing up. 235 */ 236 if (q->p_flag & P_TRACED) { 237 q->p_flag &= ~(P_TRACED|P_WAITED|P_FSTRACE); 238 psignal(q, SIGKILL); 239 } 240 } 241 242 /* 243 * Save exit status and final rusage info, adding in child rusage 244 * info and self times. 245 */ 246 p->p_xstat = rv; 247 *p->p_ru = p->p_stats->p_ru; 248 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 249 ruadd(p->p_ru, &p->p_stats->p_cru); 250 251 /* 252 * Notify parent that we're gone. 253 */ 254 if ((p->p_flag & P_FSTRACE) == 0) 255 psignal(p->p_pptr, SIGCHLD); 256 wakeup((caddr_t)p->p_pptr); 257 258 /* 259 * Clear curproc after we've done all operations 260 * that could block, and before tearing down the rest 261 * of the process state that might be used from clock, etc. 262 * Also, can't clear curproc while we're still runnable, 263 * as we're not on a run queue (we are current, just not 264 * a proper proc any longer!). 265 * 266 * Other substructures are freed from wait(). 267 */ 268 curproc = NULL; 269 if (--p->p_limit->p_refcnt == 0) 270 FREE(p->p_limit, M_SUBPROC); 271 272 /* 273 * Finally, call machine-dependent code to release the remaining 274 * resources including address space, the kernel stack and pcb. 275 * The address space is released by "vmspace_free(p->p_vmspace)"; 276 * This is machine-dependent, as we may have to change stacks 277 * or ensure that the current one isn't reallocated before we 278 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 279 * our execution (pun intended). 280 */ 281 cpu_exit(p); 282 } 283 284 int 285 sys_wait4(q, v, retval) 286 register struct proc *q; 287 void *v; 288 register_t *retval; 289 { 290 register struct sys_wait4_args /* { 291 syscallarg(int) pid; 292 syscallarg(int *) status; 293 syscallarg(int) options; 294 syscallarg(struct rusage *) rusage; 295 } */ *uap = v; 296 register int nfound; 297 register struct proc *p, *t; 298 int status, error; 299 300 if (SCARG(uap, pid) == 0) 301 SCARG(uap, pid) = -q->p_pgid; 302 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG)) 303 return (EINVAL); 304 305 loop: 306 nfound = 0; 307 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 308 if (SCARG(uap, pid) != WAIT_ANY && 309 p->p_pid != SCARG(uap, pid) && 310 p->p_pgid != -SCARG(uap, pid)) 311 continue; 312 nfound++; 313 if (p->p_stat == SZOMB) { 314 retval[0] = p->p_pid; 315 316 if (SCARG(uap, status)) { 317 status = p->p_xstat; /* convert to int */ 318 error = copyout((caddr_t)&status, 319 (caddr_t)SCARG(uap, status), 320 sizeof(status)); 321 if (error) 322 return (error); 323 } 324 if (SCARG(uap, rusage) && 325 (error = copyout((caddr_t)p->p_ru, 326 (caddr_t)SCARG(uap, rusage), 327 sizeof (struct rusage)))) 328 return (error); 329 /* 330 * If we got the child via ptrace(2) or procfs, and 331 * the parent is different (meaning the process was 332 * attached, rather than run as a child), then we need 333 * to give it back to the old parent, and send the 334 * parent a SIGCHLD. The rest of the cleanup will be 335 * done when the old parent waits on the child. 336 */ 337 if ((p->p_flag & P_TRACED) && 338 p->p_oppid != p->p_pptr->p_pid) { 339 t = pfind(p->p_oppid); 340 proc_reparent(p, t ? t : initproc); 341 p->p_oppid = 0; 342 p->p_flag &= ~(P_TRACED|P_WAITED|P_FSTRACE); 343 psignal(p->p_pptr, SIGCHLD); 344 wakeup((caddr_t)p->p_pptr); 345 return (0); 346 } 347 p->p_xstat = 0; 348 ruadd(&q->p_stats->p_cru, p->p_ru); 349 FREE(p->p_ru, M_ZOMBIE); 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 * Decrement the count of procs running with this uid. 361 */ 362 (void)chgproccnt(p->p_cred->p_ruid, -1); 363 364 /* 365 * Free up credentials. 366 */ 367 if (--p->p_cred->p_refcnt == 0) { 368 crfree(p->p_cred->pc_ucred); 369 FREE(p->p_cred, M_SUBPROC); 370 } 371 372 /* 373 * Release reference to text vnode 374 */ 375 if (p->p_textvp) 376 vrele(p->p_textvp); 377 378 /* 379 * Give machine-dependent layer a chance 380 * to free anything that cpu_exit couldn't 381 * release while still running in process context. 382 */ 383 cpu_wait(p); 384 FREE(p, M_PROC); 385 nprocs--; 386 return (0); 387 } 388 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 389 (p->p_flag & P_TRACED || SCARG(uap, options) & WUNTRACED)) { 390 p->p_flag |= P_WAITED; 391 retval[0] = p->p_pid; 392 393 if (SCARG(uap, status)) { 394 status = W_STOPCODE(p->p_xstat); 395 error = copyout((caddr_t)&status, 396 (caddr_t)SCARG(uap, status), 397 sizeof(status)); 398 } else 399 error = 0; 400 return (error); 401 } 402 } 403 if (nfound == 0) 404 return (ECHILD); 405 if (SCARG(uap, options) & WNOHANG) { 406 retval[0] = 0; 407 return (0); 408 } 409 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) != 0) 410 return (error); 411 goto loop; 412 } 413 414 /* 415 * make process 'parent' the new parent of process 'child'. 416 */ 417 void 418 proc_reparent(child, parent) 419 register struct proc *child; 420 register struct proc *parent; 421 { 422 423 if (child->p_pptr == parent) 424 return; 425 426 LIST_REMOVE(child, p_sibling); 427 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 428 child->p_pptr = parent; 429 } 430