1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)kern_exit.c 7.47 (Berkeley) 07/08/92 8 */ 9 10 #include "param.h" 11 #include "systm.h" 12 #include "map.h" 13 #include "ioctl.h" 14 #include "proc.h" 15 #include "tty.h" 16 #include "time.h" 17 #include "resource.h" 18 #include "kernel.h" 19 #include "buf.h" 20 #include "wait.h" 21 #include "file.h" 22 #include "vnode.h" 23 #include "syslog.h" 24 #include "malloc.h" 25 #include "resourcevar.h" 26 #include "ptrace.h" 27 28 #include "machine/cpu.h" 29 #ifdef COMPAT_43 30 #include "machine/reg.h" 31 #include "machine/psl.h" 32 #endif 33 34 #include "vm/vm.h" 35 #include "vm/vm_kern.h" 36 37 /* 38 * Exit system call: pass back caller's arg 39 */ 40 /* ARGSUSED */ 41 rexit(p, uap, retval) 42 struct proc *p; 43 struct args { 44 int rval; 45 } *uap; 46 int *retval; 47 { 48 49 exit(p, W_EXITCODE(uap->rval, 0)); 50 /* NOTREACHED */ 51 } 52 53 /* 54 * Exit: deallocate address space and other resources, 55 * change proc state to zombie, and unlink proc from allproc 56 * and parent's lists. Save exit status and rusage for wait(). 57 * Check for child processes and orphan them. 58 */ 59 exit(p, rv) 60 register struct proc *p; 61 int rv; 62 { 63 register struct proc *q, *nq; 64 register struct proc **pp; 65 register struct vmspace *vm; 66 int s; 67 68 if (p->p_pid == 1) 69 panic("init died (signal %d, exit %d)", 70 WTERMSIG(rv), WEXITSTATUS(rv)); 71 #ifdef PGINPROF 72 vmsizmon(); 73 #endif 74 if (p->p_flag & SPROFIL) 75 stopprofclock(p); 76 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 77 M_ZOMBIE, M_WAITOK); 78 /* 79 * If parent is waiting for us to exit or exec, 80 * SPPWAIT is set; we will wakeup the parent below. 81 */ 82 p->p_flag &= ~(STRC|SPPWAIT); 83 p->p_flag |= SWEXIT; 84 p->p_sigignore = ~0; 85 p->p_sig = 0; 86 untimeout(realitexpire, (caddr_t)p); 87 88 /* 89 * Close open files and release open-file table. 90 * This may block! 91 */ 92 fdfree(p); 93 94 /* The next two chunks should probably be moved to vmspace_exit. */ 95 vm = p->p_vmspace; 96 #ifdef SYSVSHM 97 if (vm->vm_shm) 98 shmexit(p); 99 #endif 100 /* 101 * Release user portion of address space. 102 * This releases references to vnodes, 103 * which could cause I/O if the file has been unlinked. 104 * Need to do this early enough that we can still sleep. 105 * Can't free the entire vmspace as the kernel stack 106 * may be mapped within that space also. 107 */ 108 if (vm->vm_refcnt == 1) 109 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 110 VM_MAXUSER_ADDRESS); 111 112 if (SESS_LEADER(p)) { 113 register struct session *sp = p->p_session; 114 115 if (sp->s_ttyvp) { 116 /* 117 * Controlling process. 118 * Signal foreground pgrp, 119 * drain controlling terminal 120 * and revoke access to controlling terminal. 121 */ 122 if (sp->s_ttyp->t_session == sp) { 123 if (sp->s_ttyp->t_pgrp) 124 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 125 (void) ttywait(sp->s_ttyp); 126 vgoneall(sp->s_ttyvp); 127 } 128 vrele(sp->s_ttyvp); 129 sp->s_ttyvp = NULL; 130 /* 131 * s_ttyp is not zero'd; we use this to indicate 132 * that the session once had a controlling terminal. 133 * (for logging and informational purposes) 134 */ 135 } 136 sp->s_leader = NULL; 137 } 138 fixjobc(p, p->p_pgrp, 0); 139 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 140 (void) acct(p); 141 #ifdef KTRACE 142 /* 143 * release trace file 144 */ 145 p->p_traceflag = 0; /* don't trace the vrele() */ 146 if (p->p_tracep) 147 vrele(p->p_tracep); 148 #endif 149 /* 150 * Remove proc from allproc queue and pidhash chain. 151 * Place onto zombproc. Unlink from parent's child list. 152 */ 153 if (*p->p_prev = p->p_nxt) 154 p->p_nxt->p_prev = p->p_prev; 155 if (p->p_nxt = zombproc) 156 p->p_nxt->p_prev = &p->p_nxt; 157 p->p_prev = &zombproc; 158 zombproc = p; 159 p->p_stat = SZOMB; 160 161 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 162 if (*pp == p) { 163 *pp = p->p_hash; 164 goto done; 165 } 166 panic("exit"); 167 done: 168 169 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 170 wakeup((caddr_t) initproc); 171 for (q = p->p_cptr; q != NULL; q = nq) { 172 nq = q->p_osptr; 173 if (nq != NULL) 174 nq->p_ysptr = NULL; 175 if (initproc->p_cptr) 176 initproc->p_cptr->p_ysptr = q; 177 q->p_osptr = initproc->p_cptr; 178 q->p_ysptr = NULL; 179 initproc->p_cptr = q; 180 181 q->p_pptr = initproc; 182 /* 183 * Traced processes are killed 184 * since their existence means someone is screwing up. 185 */ 186 if (q->p_flag&STRC) { 187 q->p_flag &= ~STRC; 188 psignal(q, SIGKILL); 189 } 190 } 191 p->p_cptr = NULL; 192 193 /* 194 * Save exit status and final rusage info, adding in child rusage 195 * info and self times. 196 */ 197 p->p_xstat = rv; 198 *p->p_ru = p->p_stats->p_ru; 199 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 200 ruadd(p->p_ru, &p->p_stats->p_cru); 201 202 /* 203 * Notify parent that we're gone. 204 */ 205 psignal(p->p_pptr, SIGCHLD); 206 wakeup((caddr_t)p->p_pptr); 207 #if defined(tahoe) 208 /* move this to cpu_exit */ 209 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 210 #endif 211 /* 212 * Clear curproc after we've done all operations 213 * that could block, and before tearing down the rest 214 * of the process state that might be used from clock, etc. 215 * Also, can't clear curproc while we're still runnable, 216 * as we're not on a run queue (we are current, just not 217 * a proper proc any longer!). 218 * 219 * Other substructures are freed from wait(). 220 */ 221 curproc = NULL; 222 if (--p->p_limit->p_refcnt == 0) 223 FREE(p->p_limit, M_SUBPROC); 224 225 /* 226 * Finally, call machine-dependent code to release the remaining 227 * resources including address space, the kernel stack and pcb. 228 * The address space is released by "vmspace_free(p->p_vmspace)"; 229 * This is machine-dependent, as we may have to change stacks 230 * or ensure that the current one isn't reallocated before we 231 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 232 * our execution (pun intended). 233 */ 234 cpu_exit(p); 235 /* NOTREACHED */ 236 } 237 238 #ifdef COMPAT_43 239 owait(p, uap, retval) 240 struct proc *p; 241 register struct args { 242 int pid; 243 int *status; 244 int options; 245 struct rusage *rusage; 246 int compat; 247 } *uap; 248 int *retval; 249 { 250 251 #ifdef PSL_ALLCC 252 if ((p->p_md.md_regs[PS] & PSL_ALLCC) != PSL_ALLCC) { 253 uap->options = 0; 254 uap->rusage = 0; 255 } else { 256 uap->options = p->p_md.md_regs[R0]; 257 uap->rusage = (struct rusage *)p->p_md.md_regs[R1]; 258 } 259 #else 260 uap->options = 0; 261 uap->rusage = 0; 262 #endif 263 uap->pid = WAIT_ANY; 264 uap->status = 0; 265 uap->compat = 1; 266 return (wait1(p, uap, retval)); 267 } 268 269 wait4(p, uap, retval) 270 struct proc *p; 271 struct args { 272 int pid; 273 int *status; 274 int options; 275 struct rusage *rusage; 276 int compat; 277 } *uap; 278 int *retval; 279 { 280 281 uap->compat = 0; 282 return (wait1(p, uap, retval)); 283 } 284 #else 285 #define wait1 wait4 286 #endif 287 288 /* 289 * Wait: check child processes to see if any have exited, 290 * stopped under trace, or (optionally) stopped by a signal. 291 * Pass back status and deallocate exited child's proc structure. 292 */ 293 wait1(q, uap, retval) 294 register struct proc *q; 295 register struct args { 296 int pid; 297 int *status; 298 int options; 299 struct rusage *rusage; 300 #ifdef COMPAT_43 301 int compat; 302 #endif 303 } *uap; 304 int retval[]; 305 { 306 register int nfound; 307 register struct proc *p, *t; 308 int status, error; 309 310 if (uap->pid == 0) 311 uap->pid = -q->p_pgid; 312 #ifdef notyet 313 if (uap->options &~ (WUNTRACED|WNOHANG)) 314 return (EINVAL); 315 #endif 316 loop: 317 nfound = 0; 318 for (p = q->p_cptr; p; p = p->p_osptr) { 319 if (uap->pid != WAIT_ANY && 320 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 321 continue; 322 nfound++; 323 if (p->p_stat == SZOMB) { 324 retval[0] = p->p_pid; 325 #ifdef COMPAT_43 326 if (uap->compat) 327 retval[1] = p->p_xstat; 328 else 329 #endif 330 if (uap->status) { 331 status = p->p_xstat; /* convert to int */ 332 if (error = copyout((caddr_t)&status, 333 (caddr_t)uap->status, sizeof(status))) 334 return (error); 335 } 336 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 337 (caddr_t)uap->rusage, sizeof (struct rusage)))) 338 return (error); 339 /* 340 * If we got the child via a ptrace 'attach', 341 * we need to give it back to the old parent. 342 */ 343 if (p->p_oppid && (t = pfind(p->p_oppid))) { 344 p->p_oppid = 0; 345 proc_reparent(p, t); 346 psignal(t, SIGCHLD); 347 wakeup((caddr_t)t); 348 return (0); 349 } 350 p->p_xstat = 0; 351 ruadd(&q->p_stats->p_cru, p->p_ru); 352 FREE(p->p_ru, M_ZOMBIE); 353 if (--p->p_cred->p_refcnt == 0) { 354 crfree(p->p_cred->pc_ucred); 355 FREE(p->p_cred, M_SUBPROC); 356 } 357 358 /* 359 * Finally finished with old proc entry. 360 * Unlink it from its process group and free it. 361 */ 362 leavepgrp(p); 363 if (*p->p_prev = p->p_nxt) /* off zombproc */ 364 p->p_nxt->p_prev = p->p_prev; 365 if (q = p->p_ysptr) 366 q->p_osptr = p->p_osptr; 367 if (q = p->p_osptr) 368 q->p_ysptr = p->p_ysptr; 369 if ((q = p->p_pptr)->p_cptr == p) 370 q->p_cptr = p->p_osptr; 371 372 /* 373 * Give machine-dependent layer a chance 374 * to free anything that cpu_exit couldn't 375 * release while still running in process context. 376 */ 377 cpu_wait(p); 378 FREE(p, M_PROC); 379 nprocs--; 380 return (0); 381 } 382 if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 && 383 (p->p_flag & STRC || uap->options & WUNTRACED)) { 384 p->p_flag |= SWTED; 385 retval[0] = p->p_pid; 386 #ifdef COMPAT_43 387 if (uap->compat) { 388 retval[1] = W_STOPCODE(p->p_xstat); 389 error = 0; 390 } else 391 #endif 392 if (uap->status) { 393 status = W_STOPCODE(p->p_xstat); 394 error = copyout((caddr_t)&status, 395 (caddr_t)uap->status, sizeof(status)); 396 } else 397 error = 0; 398 return (error); 399 } 400 } 401 if (nfound == 0) 402 return (ECHILD); 403 if (uap->options & WNOHANG) { 404 retval[0] = 0; 405 return (0); 406 } 407 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 408 return (error); 409 goto loop; 410 } 411 412 /* 413 * make process 'parent' the new parent of process 'child'. 414 */ 415 void 416 proc_reparent(child, parent) 417 register struct proc *child; 418 register struct proc *parent; 419 { 420 register struct proc *o; 421 register struct proc *y; 422 423 if (child->p_pptr == parent) 424 return; 425 426 /* fix up the child linkage for the old parent */ 427 o = child->p_osptr; 428 y = child->p_ysptr; 429 if (y) 430 y->p_osptr = o; 431 if (o) 432 o->p_ysptr = y; 433 if (child->p_pptr->p_cptr == child) 434 child->p_pptr->p_cptr = o; 435 436 /* fix up child linkage for new parent */ 437 o = parent->p_cptr; 438 if (o) 439 o->p_ysptr = child; 440 child->p_osptr = o; 441 child->p_ysptr = NULL; 442 parent->p_cptr = child; 443 child->p_pptr = parent; 444 } 445