1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * %sccs.include.redist.c% 11 * 12 * @(#)kern_exit.c 8.7 (Berkeley) 02/12/94 13 */ 14 15 #include <sys/param.h> 16 #include <sys/systm.h> 17 #include <sys/map.h> 18 #include <sys/ioctl.h> 19 #include <sys/proc.h> 20 #include <sys/tty.h> 21 #include <sys/time.h> 22 #include <sys/resource.h> 23 #include <sys/kernel.h> 24 #include <sys/buf.h> 25 #include <sys/wait.h> 26 #include <sys/file.h> 27 #include <sys/vnode.h> 28 #include <sys/syslog.h> 29 #include <sys/malloc.h> 30 #include <sys/resourcevar.h> 31 #include <sys/ptrace.h> 32 33 #include <machine/cpu.h> 34 #ifdef COMPAT_43 35 #include <machine/reg.h> 36 #include <machine/psl.h> 37 #endif 38 39 #include <vm/vm.h> 40 #include <vm/vm_kern.h> 41 42 __dead void cpu_exit __P((struct proc *)); 43 __dead void exit1 __P((struct proc *, int)); 44 45 /* 46 * exit -- 47 * Death of process. 48 */ 49 struct rexit_args { 50 int rval; 51 }; 52 __dead void 53 exit(p, uap, retval) 54 struct proc *p; 55 struct rexit_args *uap; 56 int *retval; 57 { 58 59 exit1(p, W_EXITCODE(uap->rval, 0)); 60 /* NOTREACHED */ 61 } 62 63 /* 64 * Exit: deallocate address space and other resources, change proc state 65 * to zombie, and unlink proc from allproc and parent's lists. Save exit 66 * status and rusage for wait(). Check for child processes and orphan them. 67 */ 68 __dead void 69 exit1(p, rv) 70 register struct proc *p; 71 int rv; 72 { 73 register struct proc *q, *nq; 74 register struct proc **pp; 75 register struct vmspace *vm; 76 77 if (p->p_pid == 1) 78 panic("init died (signal %d, exit %d)", 79 WTERMSIG(rv), WEXITSTATUS(rv)); 80 #ifdef PGINPROF 81 vmsizmon(); 82 #endif 83 if (p->p_flag & P_PROFIL) 84 stopprofclock(p); 85 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 86 M_ZOMBIE, M_WAITOK); 87 /* 88 * If parent is waiting for us to exit or exec, 89 * P_PPWAIT is set; we will wakeup the parent below. 90 */ 91 p->p_flag &= ~(P_TRACED | P_PPWAIT); 92 p->p_flag |= P_WEXIT; 93 p->p_sigignore = ~0; 94 p->p_siglist = 0; 95 untimeout(realitexpire, (caddr_t)p); 96 97 /* 98 * Close open files and release open-file table. 99 * This may block! 100 */ 101 fdfree(p); 102 103 /* The next two chunks should probably be moved to vmspace_exit. */ 104 vm = p->p_vmspace; 105 #ifdef SYSVSHM 106 if (vm->vm_shm) 107 shmexit(p); 108 #endif 109 /* 110 * Release user portion of address space. 111 * This releases references to vnodes, 112 * which could cause I/O if the file has been unlinked. 113 * Need to do this early enough that we can still sleep. 114 * Can't free the entire vmspace as the kernel stack 115 * may be mapped within that space also. 116 */ 117 if (vm->vm_refcnt == 1) 118 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 119 VM_MAXUSER_ADDRESS); 120 121 if (SESS_LEADER(p)) { 122 register struct session *sp = p->p_session; 123 124 if (sp->s_ttyvp) { 125 /* 126 * Controlling process. 127 * Signal foreground pgrp, 128 * drain controlling terminal 129 * and revoke access to controlling terminal. 130 */ 131 if (sp->s_ttyp->t_session == sp) { 132 if (sp->s_ttyp->t_pgrp) 133 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 134 (void) ttywait(sp->s_ttyp); 135 /* 136 * The tty could have been revoked 137 * if we blocked. 138 */ 139 if (sp->s_ttyvp) 140 vgoneall(sp->s_ttyvp); 141 } 142 if (sp->s_ttyvp) 143 vrele(sp->s_ttyvp); 144 sp->s_ttyvp = NULL; 145 /* 146 * s_ttyp is not zero'd; we use this to indicate 147 * that the session once had a controlling terminal. 148 * (for logging and informational purposes) 149 */ 150 } 151 sp->s_leader = NULL; 152 } 153 fixjobc(p, p->p_pgrp, 0); 154 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 155 (void)acct_process(p); 156 #ifdef KTRACE 157 /* 158 * release trace file 159 */ 160 p->p_traceflag = 0; /* don't trace the vrele() */ 161 if (p->p_tracep) 162 vrele(p->p_tracep); 163 #endif 164 /* 165 * Remove proc from allproc queue and pidhash chain. 166 * Place onto zombproc. Unlink from parent's child list. 167 */ 168 if (*p->p_prev = p->p_next) 169 p->p_next->p_prev = p->p_prev; 170 if (p->p_next = zombproc) 171 p->p_next->p_prev = &p->p_next; 172 p->p_prev = &zombproc; 173 zombproc = p; 174 p->p_stat = SZOMB; 175 176 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 177 if (*pp == p) { 178 *pp = p->p_hash; 179 goto done; 180 } 181 panic("exit"); 182 done: 183 184 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 185 wakeup((caddr_t) initproc); 186 for (q = p->p_cptr; q != NULL; q = nq) { 187 nq = q->p_osptr; 188 if (nq != NULL) 189 nq->p_ysptr = NULL; 190 if (initproc->p_cptr) 191 initproc->p_cptr->p_ysptr = q; 192 q->p_osptr = initproc->p_cptr; 193 q->p_ysptr = NULL; 194 initproc->p_cptr = q; 195 196 q->p_pptr = initproc; 197 /* 198 * Traced processes are killed 199 * since their existence means someone is screwing up. 200 */ 201 if (q->p_flag & P_TRACED) { 202 q->p_flag &= ~P_TRACED; 203 psignal(q, SIGKILL); 204 } 205 } 206 p->p_cptr = NULL; 207 208 /* 209 * Save exit status and final rusage info, adding in child rusage 210 * info and self times. 211 */ 212 p->p_xstat = rv; 213 *p->p_ru = p->p_stats->p_ru; 214 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 215 ruadd(p->p_ru, &p->p_stats->p_cru); 216 217 /* 218 * Notify parent that we're gone. 219 */ 220 psignal(p->p_pptr, SIGCHLD); 221 wakeup((caddr_t)p->p_pptr); 222 #if defined(tahoe) 223 /* move this to cpu_exit */ 224 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 225 #endif 226 /* 227 * Clear curproc after we've done all operations 228 * that could block, and before tearing down the rest 229 * of the process state that might be used from clock, etc. 230 * Also, can't clear curproc while we're still runnable, 231 * as we're not on a run queue (we are current, just not 232 * a proper proc any longer!). 233 * 234 * Other substructures are freed from wait(). 235 */ 236 curproc = NULL; 237 if (--p->p_limit->p_refcnt == 0) 238 FREE(p->p_limit, M_SUBPROC); 239 240 /* 241 * Finally, call machine-dependent code to release the remaining 242 * resources including address space, the kernel stack and pcb. 243 * The address space is released by "vmspace_free(p->p_vmspace)"; 244 * This is machine-dependent, as we may have to change stacks 245 * or ensure that the current one isn't reallocated before we 246 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 247 * our execution (pun intended). 248 */ 249 cpu_exit(p); 250 } 251 252 struct wait_args { 253 int pid; 254 int *status; 255 int options; 256 struct rusage *rusage; 257 #ifdef COMPAT_43 258 int compat; /* pseudo */ 259 #endif 260 }; 261 262 #ifdef COMPAT_43 263 #if defined(hp300) || defined(luna68k) 264 #include <machine/frame.h> 265 #define GETPS(rp) ((struct frame *)(rp))->f_sr 266 #else 267 #define GETPS(rp) (rp)[PS] 268 #endif 269 270 owait(p, uap, retval) 271 struct proc *p; 272 register struct wait_args *uap; 273 int *retval; 274 { 275 276 #ifdef PSL_ALLCC 277 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 278 uap->options = 0; 279 uap->rusage = NULL; 280 } else { 281 uap->options = p->p_md.md_regs[R0]; 282 uap->rusage = (struct rusage *)p->p_md.md_regs[R1]; 283 } 284 #else 285 uap->options = 0; 286 uap->rusage = NULL; 287 #endif 288 uap->pid = WAIT_ANY; 289 uap->status = NULL; 290 uap->compat = 1; 291 return (wait1(p, uap, retval)); 292 } 293 294 wait4(p, uap, retval) 295 struct proc *p; 296 struct wait_args *uap; 297 int *retval; 298 { 299 300 uap->compat = 0; 301 return (wait1(p, uap, retval)); 302 } 303 #else 304 #define wait1 wait4 305 #endif 306 307 int 308 wait1(q, uap, retval) 309 register struct proc *q; 310 register struct wait_args *uap; 311 int retval[]; 312 { 313 register int nfound; 314 register struct proc *p, *t; 315 int status, error; 316 317 if (uap->pid == 0) 318 uap->pid = -q->p_pgid; 319 #ifdef notyet 320 if (uap->options &~ (WUNTRACED|WNOHANG)) 321 return (EINVAL); 322 #endif 323 loop: 324 nfound = 0; 325 for (p = q->p_cptr; p; p = p->p_osptr) { 326 if (uap->pid != WAIT_ANY && 327 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 328 continue; 329 nfound++; 330 if (p->p_stat == SZOMB) { 331 retval[0] = p->p_pid; 332 #ifdef COMPAT_43 333 if (uap->compat) 334 retval[1] = p->p_xstat; 335 else 336 #endif 337 if (uap->status) { 338 status = p->p_xstat; /* convert to int */ 339 if (error = copyout((caddr_t)&status, 340 (caddr_t)uap->status, sizeof(status))) 341 return (error); 342 } 343 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 344 (caddr_t)uap->rusage, sizeof (struct rusage)))) 345 return (error); 346 /* 347 * If we got the child via a ptrace 'attach', 348 * we need to give it back to the old parent. 349 */ 350 if (p->p_oppid && (t = pfind(p->p_oppid))) { 351 p->p_oppid = 0; 352 proc_reparent(p, t); 353 psignal(t, SIGCHLD); 354 wakeup((caddr_t)t); 355 return (0); 356 } 357 p->p_xstat = 0; 358 ruadd(&q->p_stats->p_cru, p->p_ru); 359 FREE(p->p_ru, M_ZOMBIE); 360 361 /* 362 * Decrement the count of procs running with this uid. 363 */ 364 (void)chgproccnt(p->p_cred->p_ruid, -1); 365 366 /* 367 * Free up credentials. 368 */ 369 if (--p->p_cred->p_refcnt == 0) { 370 crfree(p->p_cred->pc_ucred); 371 FREE(p->p_cred, M_SUBPROC); 372 } 373 374 /* 375 * Release reference to text vnode 376 */ 377 if (p->p_textvp) 378 vrele(p->p_textvp); 379 380 /* 381 * Finally finished with old proc entry. 382 * Unlink it from its process group and free it. 383 */ 384 leavepgrp(p); 385 if (*p->p_prev = p->p_next) /* off zombproc */ 386 p->p_next->p_prev = p->p_prev; 387 if (q = p->p_ysptr) 388 q->p_osptr = p->p_osptr; 389 if (q = p->p_osptr) 390 q->p_ysptr = p->p_ysptr; 391 if ((q = p->p_pptr)->p_cptr == p) 392 q->p_cptr = p->p_osptr; 393 394 /* 395 * Give machine-dependent layer a chance 396 * to free anything that cpu_exit couldn't 397 * release while still running in process context. 398 */ 399 cpu_wait(p); 400 FREE(p, M_PROC); 401 nprocs--; 402 return (0); 403 } 404 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 405 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 406 p->p_flag |= P_WAITED; 407 retval[0] = p->p_pid; 408 #ifdef COMPAT_43 409 if (uap->compat) { 410 retval[1] = W_STOPCODE(p->p_xstat); 411 error = 0; 412 } else 413 #endif 414 if (uap->status) { 415 status = W_STOPCODE(p->p_xstat); 416 error = copyout((caddr_t)&status, 417 (caddr_t)uap->status, sizeof(status)); 418 } else 419 error = 0; 420 return (error); 421 } 422 } 423 if (nfound == 0) 424 return (ECHILD); 425 if (uap->options & WNOHANG) { 426 retval[0] = 0; 427 return (0); 428 } 429 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 430 return (error); 431 goto loop; 432 } 433 434 /* 435 * make process 'parent' the new parent of process 'child'. 436 */ 437 void 438 proc_reparent(child, parent) 439 register struct proc *child; 440 register struct proc *parent; 441 { 442 register struct proc *o; 443 register struct proc *y; 444 445 if (child->p_pptr == parent) 446 return; 447 448 /* fix up the child linkage for the old parent */ 449 o = child->p_osptr; 450 y = child->p_ysptr; 451 if (y) 452 y->p_osptr = o; 453 if (o) 454 o->p_ysptr = y; 455 if (child->p_pptr->p_cptr == child) 456 child->p_pptr->p_cptr = o; 457 458 /* fix up child linkage for new parent */ 459 o = parent->p_cptr; 460 if (o) 461 o->p_ysptr = child; 462 child->p_osptr = o; 463 child->p_ysptr = NULL; 464 parent->p_cptr = child; 465 child->p_pptr = parent; 466 } 467