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 8.8 (Berkeley) 08/22/94 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 LIST_REMOVE(p, p_list); 169 LIST_INSERT_HEAD(&zombproc, p, p_list); 170 p->p_stat = SZOMB; 171 172 LIST_REMOVE(p, p_hash); 173 174 q = p->p_children.lh_first; 175 if (q) /* only need this if any child is S_ZOMB */ 176 wakeup((caddr_t) initproc); 177 for (; q != 0; q = nq) { 178 nq = q->p_sibling.le_next; 179 LIST_REMOVE(q, p_sibling); 180 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling); 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 & P_TRACED) { 187 q->p_flag &= ~P_TRACED; 188 psignal(q, SIGKILL); 189 } 190 } 191 192 /* 193 * Save exit status and final rusage info, adding in child rusage 194 * info and self times. 195 */ 196 p->p_xstat = rv; 197 *p->p_ru = p->p_stats->p_ru; 198 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 199 ruadd(p->p_ru, &p->p_stats->p_cru); 200 201 /* 202 * Notify parent that we're gone. 203 */ 204 psignal(p->p_pptr, SIGCHLD); 205 wakeup((caddr_t)p->p_pptr); 206 #if defined(tahoe) 207 /* move this to cpu_exit */ 208 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 209 #endif 210 /* 211 * Clear curproc after we've done all operations 212 * that could block, and before tearing down the rest 213 * of the process state that might be used from clock, etc. 214 * Also, can't clear curproc while we're still runnable, 215 * as we're not on a run queue (we are current, just not 216 * a proper proc any longer!). 217 * 218 * Other substructures are freed from wait(). 219 */ 220 curproc = NULL; 221 if (--p->p_limit->p_refcnt == 0) 222 FREE(p->p_limit, M_SUBPROC); 223 224 /* 225 * Finally, call machine-dependent code to release the remaining 226 * resources including address space, the kernel stack and pcb. 227 * The address space is released by "vmspace_free(p->p_vmspace)"; 228 * This is machine-dependent, as we may have to change stacks 229 * or ensure that the current one isn't reallocated before we 230 * finish. cpu_exit will end with a call to cpu_swtch(), finishing 231 * our execution (pun intended). 232 */ 233 cpu_exit(p); 234 } 235 236 struct wait_args { 237 int pid; 238 int *status; 239 int options; 240 struct rusage *rusage; 241 #ifdef COMPAT_43 242 int compat; /* pseudo */ 243 #endif 244 }; 245 246 #ifdef COMPAT_43 247 #if defined(hp300) || defined(luna68k) 248 #include <machine/frame.h> 249 #define GETPS(rp) ((struct frame *)(rp))->f_sr 250 #else 251 #define GETPS(rp) (rp)[PS] 252 #endif 253 254 owait(p, uap, retval) 255 struct proc *p; 256 register struct wait_args *uap; 257 int *retval; 258 { 259 260 #ifdef PSL_ALLCC 261 if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { 262 uap->options = 0; 263 uap->rusage = NULL; 264 } else { 265 uap->options = p->p_md.md_regs[R0]; 266 uap->rusage = (struct rusage *)p->p_md.md_regs[R1]; 267 } 268 #else 269 uap->options = 0; 270 uap->rusage = NULL; 271 #endif 272 uap->pid = WAIT_ANY; 273 uap->status = NULL; 274 uap->compat = 1; 275 return (wait1(p, uap, retval)); 276 } 277 278 wait4(p, uap, retval) 279 struct proc *p; 280 struct wait_args *uap; 281 int *retval; 282 { 283 284 uap->compat = 0; 285 return (wait1(p, uap, retval)); 286 } 287 #else 288 #define wait1 wait4 289 #endif 290 291 int 292 wait1(q, uap, retval) 293 register struct proc *q; 294 register struct wait_args *uap; 295 int retval[]; 296 { 297 register int nfound; 298 register struct proc *p, *t; 299 int status, error; 300 301 if (uap->pid == 0) 302 uap->pid = -q->p_pgid; 303 #ifdef notyet 304 if (uap->options &~ (WUNTRACED|WNOHANG)) 305 return (EINVAL); 306 #endif 307 loop: 308 nfound = 0; 309 for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 310 if (uap->pid != WAIT_ANY && 311 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 312 continue; 313 nfound++; 314 if (p->p_stat == SZOMB) { 315 retval[0] = p->p_pid; 316 #ifdef COMPAT_43 317 if (uap->compat) 318 retval[1] = p->p_xstat; 319 else 320 #endif 321 if (uap->status) { 322 status = p->p_xstat; /* convert to int */ 323 if (error = copyout((caddr_t)&status, 324 (caddr_t)uap->status, sizeof(status))) 325 return (error); 326 } 327 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 328 (caddr_t)uap->rusage, sizeof (struct rusage)))) 329 return (error); 330 /* 331 * If we got the child via a ptrace 'attach', 332 * we need to give it back to the old parent. 333 */ 334 if (p->p_oppid && (t = pfind(p->p_oppid))) { 335 p->p_oppid = 0; 336 proc_reparent(p, t); 337 psignal(t, SIGCHLD); 338 wakeup((caddr_t)t); 339 return (0); 340 } 341 p->p_xstat = 0; 342 ruadd(&q->p_stats->p_cru, p->p_ru); 343 FREE(p->p_ru, M_ZOMBIE); 344 345 /* 346 * Decrement the count of procs running with this uid. 347 */ 348 (void)chgproccnt(p->p_cred->p_ruid, -1); 349 350 /* 351 * Free up credentials. 352 */ 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 * Release reference to text vnode 360 */ 361 if (p->p_textvp) 362 vrele(p->p_textvp); 363 364 /* 365 * Finally finished with old proc entry. 366 * Unlink it from its process group and free it. 367 */ 368 leavepgrp(p); 369 LIST_REMOVE(p, p_list); /* off zombproc */ 370 LIST_REMOVE(p, p_sibling); 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 & P_WAITED) == 0 && 383 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 384 p->p_flag |= P_WAITED; 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 { 420 421 if (child->p_pptr == parent) 422 return; 423 424 LIST_REMOVE(child, p_sibling); 425 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 426 child->p_pptr = parent; 427 } 428