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 8.6 (Berkeley) 01/21/94 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 vgoneall(sp->s_ttyvp); 136 } 137 vrele(sp->s_ttyvp); 138 sp->s_ttyvp = NULL; 139 /* 140 * s_ttyp is not zero'd; we use this to indicate 141 * that the session once had a controlling terminal. 142 * (for logging and informational purposes) 143 */ 144 } 145 sp->s_leader = NULL; 146 } 147 fixjobc(p, p->p_pgrp, 0); 148 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 149 (void)acct_process(p); 150 #ifdef KTRACE 151 /* 152 * release trace file 153 */ 154 p->p_traceflag = 0; /* don't trace the vrele() */ 155 if (p->p_tracep) 156 vrele(p->p_tracep); 157 #endif 158 /* 159 * Remove proc from allproc queue and pidhash chain. 160 * Place onto zombproc. Unlink from parent's child list. 161 */ 162 if (*p->p_prev = p->p_next) 163 p->p_next->p_prev = p->p_prev; 164 if (p->p_next = zombproc) 165 p->p_next->p_prev = &p->p_next; 166 p->p_prev = &zombproc; 167 zombproc = p; 168 p->p_stat = SZOMB; 169 170 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 171 if (*pp == p) { 172 *pp = p->p_hash; 173 goto done; 174 } 175 panic("exit"); 176 done: 177 178 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 179 wakeup((caddr_t) initproc); 180 for (q = p->p_cptr; q != NULL; q = nq) { 181 nq = q->p_osptr; 182 if (nq != NULL) 183 nq->p_ysptr = NULL; 184 if (initproc->p_cptr) 185 initproc->p_cptr->p_ysptr = q; 186 q->p_osptr = initproc->p_cptr; 187 q->p_ysptr = NULL; 188 initproc->p_cptr = q; 189 190 q->p_pptr = initproc; 191 /* 192 * Traced processes are killed 193 * since their existence means someone is screwing up. 194 */ 195 if (q->p_flag & P_TRACED) { 196 q->p_flag &= ~P_TRACED; 197 psignal(q, SIGKILL); 198 } 199 } 200 p->p_cptr = NULL; 201 202 /* 203 * Save exit status and final rusage info, adding in child rusage 204 * info and self times. 205 */ 206 p->p_xstat = rv; 207 *p->p_ru = p->p_stats->p_ru; 208 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 209 ruadd(p->p_ru, &p->p_stats->p_cru); 210 211 /* 212 * Notify parent that we're gone. 213 */ 214 psignal(p->p_pptr, SIGCHLD); 215 wakeup((caddr_t)p->p_pptr); 216 #if defined(tahoe) 217 /* move this to cpu_exit */ 218 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 219 #endif 220 /* 221 * Clear curproc after we've done all operations 222 * that could block, and before tearing down the rest 223 * of the process state that might be used from clock, etc. 224 * Also, can't clear curproc while we're still runnable, 225 * as we're not on a run queue (we are current, just not 226 * a proper proc any longer!). 227 * 228 * Other substructures are freed from wait(). 229 */ 230 curproc = NULL; 231 if (--p->p_limit->p_refcnt == 0) 232 FREE(p->p_limit, M_SUBPROC); 233 234 /* 235 * Finally, call machine-dependent code to release the remaining 236 * resources including address space, the kernel stack and pcb. 237 * The address space is released by "vmspace_free(p->p_vmspace)"; 238 * This is machine-dependent, as we may have to change stacks 239 * or ensure that the current one isn't reallocated before we 240 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 241 * our execution (pun intended). 242 */ 243 cpu_exit(p); 244 } 245 246 struct wait_args { 247 int pid; 248 int *status; 249 int options; 250 struct rusage *rusage; 251 #ifdef COMPAT_43 252 int compat; /* pseudo */ 253 #endif 254 }; 255 256 #ifdef COMPAT_43 257 #if defined(hp300) || defined(luna68k) 258 #include <machine/frame.h> 259 #define GETPS(rp) ((struct frame *)(rp))->f_sr 260 #else 261 #define GETPS(rp) (rp)[PS] 262 #endif 263 264 owait(p, uap, retval) 265 struct proc *p; 266 register struct wait_args *uap; 267 int *retval; 268 { 269 270 #ifdef PSL_ALLCC 271 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 272 uap->options = 0; 273 uap->rusage = NULL; 274 } else { 275 uap->options = p->p_md.md_regs[R0]; 276 uap->rusage = (struct rusage *)p->p_md.md_regs[R1]; 277 } 278 #else 279 uap->options = 0; 280 uap->rusage = NULL; 281 #endif 282 uap->pid = WAIT_ANY; 283 uap->status = NULL; 284 uap->compat = 1; 285 return (wait1(p, uap, retval)); 286 } 287 288 wait4(p, uap, retval) 289 struct proc *p; 290 struct wait_args *uap; 291 int *retval; 292 { 293 294 uap->compat = 0; 295 return (wait1(p, uap, retval)); 296 } 297 #else 298 #define wait1 wait4 299 #endif 300 301 int 302 wait1(q, uap, retval) 303 register struct proc *q; 304 register struct wait_args *uap; 305 int retval[]; 306 { 307 register int nfound; 308 register struct proc *p, *t; 309 int status, error; 310 311 if (uap->pid == 0) 312 uap->pid = -q->p_pgid; 313 #ifdef notyet 314 if (uap->options &~ (WUNTRACED|WNOHANG)) 315 return (EINVAL); 316 #endif 317 loop: 318 nfound = 0; 319 for (p = q->p_cptr; p; p = p->p_osptr) { 320 if (uap->pid != WAIT_ANY && 321 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 322 continue; 323 nfound++; 324 if (p->p_stat == SZOMB) { 325 retval[0] = p->p_pid; 326 #ifdef COMPAT_43 327 if (uap->compat) 328 retval[1] = p->p_xstat; 329 else 330 #endif 331 if (uap->status) { 332 status = p->p_xstat; /* convert to int */ 333 if (error = copyout((caddr_t)&status, 334 (caddr_t)uap->status, sizeof(status))) 335 return (error); 336 } 337 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 338 (caddr_t)uap->rusage, sizeof (struct rusage)))) 339 return (error); 340 /* 341 * If we got the child via a ptrace 'attach', 342 * we need to give it back to the old parent. 343 */ 344 if (p->p_oppid && (t = pfind(p->p_oppid))) { 345 p->p_oppid = 0; 346 proc_reparent(p, t); 347 psignal(t, SIGCHLD); 348 wakeup((caddr_t)t); 349 return (0); 350 } 351 p->p_xstat = 0; 352 ruadd(&q->p_stats->p_cru, p->p_ru); 353 FREE(p->p_ru, M_ZOMBIE); 354 355 /* 356 * Decrement the count of procs running with this uid. 357 */ 358 (void)chgproccnt(p->p_cred->p_ruid, -1); 359 360 /* 361 * Free up credentials. 362 */ 363 if (--p->p_cred->p_refcnt == 0) { 364 crfree(p->p_cred->pc_ucred); 365 FREE(p->p_cred, M_SUBPROC); 366 } 367 368 /* 369 * Release reference to text vnode 370 */ 371 if (p->p_textvp) 372 vrele(p->p_textvp); 373 374 /* 375 * Finally finished with old proc entry. 376 * Unlink it from its process group and free it. 377 */ 378 leavepgrp(p); 379 if (*p->p_prev = p->p_next) /* off zombproc */ 380 p->p_next->p_prev = p->p_prev; 381 if (q = p->p_ysptr) 382 q->p_osptr = p->p_osptr; 383 if (q = p->p_osptr) 384 q->p_ysptr = p->p_ysptr; 385 if ((q = p->p_pptr)->p_cptr == p) 386 q->p_cptr = p->p_osptr; 387 388 /* 389 * Give machine-dependent layer a chance 390 * to free anything that cpu_exit couldn't 391 * release while still running in process context. 392 */ 393 cpu_wait(p); 394 FREE(p, M_PROC); 395 nprocs--; 396 return (0); 397 } 398 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 && 399 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 400 p->p_flag |= P_WAITED; 401 retval[0] = p->p_pid; 402 #ifdef COMPAT_43 403 if (uap->compat) { 404 retval[1] = W_STOPCODE(p->p_xstat); 405 error = 0; 406 } else 407 #endif 408 if (uap->status) { 409 status = W_STOPCODE(p->p_xstat); 410 error = copyout((caddr_t)&status, 411 (caddr_t)uap->status, sizeof(status)); 412 } else 413 error = 0; 414 return (error); 415 } 416 } 417 if (nfound == 0) 418 return (ECHILD); 419 if (uap->options & WNOHANG) { 420 retval[0] = 0; 421 return (0); 422 } 423 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 424 return (error); 425 goto loop; 426 } 427 428 /* 429 * make process 'parent' the new parent of process 'child'. 430 */ 431 void 432 proc_reparent(child, parent) 433 register struct proc *child; 434 register struct proc *parent; 435 { 436 register struct proc *o; 437 register struct proc *y; 438 439 if (child->p_pptr == parent) 440 return; 441 442 /* fix up the child linkage for the old parent */ 443 o = child->p_osptr; 444 y = child->p_ysptr; 445 if (y) 446 y->p_osptr = o; 447 if (o) 448 o->p_ysptr = y; 449 if (child->p_pptr->p_cptr == child) 450 child->p_pptr->p_cptr = o; 451 452 /* fix up child linkage for new parent */ 453 o = parent->p_cptr; 454 if (o) 455 o->p_ysptr = child; 456 child->p_osptr = o; 457 child->p_ysptr = NULL; 458 parent->p_cptr = child; 459 child->p_pptr = parent; 460 } 461