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 7.35 (Berkeley) 06/27/91 8 */ 9 10 #include "param.h" 11 #include "systm.h" 12 #include "map.h" 13 #include "ioctl.h" 14 #include "tty.h" 15 #include "time.h" 16 #include "resource.h" 17 #include "kernel.h" 18 #include "proc.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 27 #include "machine/cpu.h" 28 #ifdef COMPAT_43 29 #include "machine/reg.h" 30 #include "machine/psl.h" 31 #endif 32 33 #include "vm/vm.h" 34 #include "vm/vm_kern.h" 35 36 /* 37 * Exit system call: pass back caller's arg 38 */ 39 /* ARGSUSED */ 40 rexit(p, uap, retval) 41 struct proc *p; 42 struct args { 43 int rval; 44 } *uap; 45 int *retval; 46 { 47 48 exit(p, W_EXITCODE(uap->rval, 0)); 49 /* NOTREACHED */ 50 } 51 52 /* 53 * Exit: deallocate address space and other resources, 54 * change proc state to zombie, and unlink proc from allproc 55 * and parent's lists. Save exit status and rusage for wait(). 56 * Check for child processes and orphan them. 57 */ 58 exit(p, rv) 59 register struct proc *p; 60 int rv; 61 { 62 register struct proc *q, *nq; 63 register struct proc **pp; 64 int s; 65 66 #ifdef PGINPROF 67 vmsizmon(); 68 #endif 69 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 70 M_ZOMBIE, M_WAITOK); 71 /* 72 * If parent is waiting for us to exit or exec, 73 * SPPWAIT is set; we will wakeup the parent below. 74 */ 75 p->p_flag &= ~(STRC|SPPWAIT); 76 p->p_flag |= SWEXIT; 77 p->p_sigignore = ~0; 78 p->p_sig = 0; 79 untimeout(realitexpire, (caddr_t)p); 80 81 /* 82 * Close open files and release open-file table. 83 * This may block! 84 */ 85 fdfree(p); 86 87 /* The next two chunks should probably be moved to vmspace_exit. */ 88 #ifdef SYSVSHM 89 if (p->p_vmspace->vm_shm) 90 shmexit(p); 91 #endif 92 /* 93 * Release user portion of address space. 94 * This releases references to vnodes, 95 * which could cause I/O if the file has been unlinked. 96 * Need to do this early enough that we can still sleep. 97 * Can't free the entire vmspace as the kernel stack 98 * may be mapped within that space also. 99 */ 100 if (p->p_vmspace->vm_refcnt == 1) 101 (void) vm_map_remove(&p->p_vmspace->vm_map, VM_MIN_ADDRESS, 102 VM_MAXUSER_ADDRESS); 103 104 if (p->p_pid == 1) 105 panic("init died"); 106 if (SESS_LEADER(p)) { 107 register struct session *sp = p->p_session; 108 109 if (sp->s_ttyvp) { 110 /* 111 * Controlling process. 112 * Signal foreground pgrp, 113 * drain controlling terminal 114 * and revoke access to controlling terminal. 115 */ 116 if (sp->s_ttyp->t_session == sp) { 117 if (sp->s_ttyp->t_pgrp) 118 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 119 (void) ttywait(sp->s_ttyp); 120 vgoneall(sp->s_ttyvp); 121 } 122 vrele(sp->s_ttyvp); 123 sp->s_ttyvp = NULL; 124 /* 125 * s_ttyp is not zero'd; we use this to indicate 126 * that the session once had a controlling terminal. 127 * (for logging and informational purposes) 128 */ 129 } 130 sp->s_leader = NULL; 131 } 132 fixjobc(p, p->p_pgrp, 0); 133 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 134 (void) acct(p); 135 if (--p->p_limit->p_refcnt == 0) 136 FREE(p->p_limit, M_SUBPROC); 137 #ifdef KTRACE 138 /* 139 * release trace file 140 */ 141 if (p->p_tracep) 142 vrele(p->p_tracep); 143 #endif 144 145 /* 146 * Remove proc from allproc queue and pidhash chain. 147 * Place onto zombproc. Unlink from parent's child list. 148 */ 149 if (*p->p_prev = p->p_nxt) 150 p->p_nxt->p_prev = p->p_prev; 151 if (p->p_nxt = zombproc) 152 p->p_nxt->p_prev = &p->p_nxt; 153 p->p_prev = &zombproc; 154 zombproc = p; 155 p->p_stat = SZOMB; 156 curproc = NULL; 157 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 158 if (*pp == p) { 159 *pp = p->p_hash; 160 goto done; 161 } 162 panic("exit"); 163 done: 164 165 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 166 wakeup((caddr_t) initproc); 167 for (q = p->p_cptr; q != NULL; q = nq) { 168 nq = q->p_osptr; 169 if (nq != NULL) 170 nq->p_ysptr = NULL; 171 if (initproc->p_cptr) 172 initproc->p_cptr->p_ysptr = q; 173 q->p_osptr = initproc->p_cptr; 174 q->p_ysptr = NULL; 175 initproc->p_cptr = q; 176 177 q->p_pptr = initproc; 178 /* 179 * Traced processes are killed 180 * since their existence means someone is screwing up. 181 */ 182 if (q->p_flag&STRC) { 183 q->p_flag &= ~STRC; 184 psignal(q, SIGKILL); 185 } 186 } 187 p->p_cptr = NULL; 188 189 /* 190 * Save exit status and final rusage info, 191 * adding in child rusage info and self times. 192 */ 193 p->p_xstat = rv; 194 *p->p_ru = p->p_stats->p_ru; 195 p->p_ru->ru_stime = p->p_stime; 196 p->p_ru->ru_utime = p->p_utime; 197 ruadd(p->p_ru, &p->p_stats->p_cru); 198 199 /* 200 * Notify parent that we're gone. 201 */ 202 psignal(p->p_pptr, SIGCHLD); 203 wakeup((caddr_t)p->p_pptr); 204 #if defined(tahoe) 205 /* move this to cpu_exit */ 206 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 207 #endif 208 /* 209 * Finally, call machine-dependent code to release the remaining 210 * resources including address space, the kernel stack and pcb. 211 * The address space is released by "vmspace_free(p->p_vmspace)"; 212 * This is machine-dependent, as we may have to change stacks 213 * or ensure that the current one isn't reallocated before we 214 * finish. cpu_exit will end with a call to swtch(), finishing 215 * our execution (pun intended). 216 */ 217 cpu_exit(p); 218 /* NOTREACHED */ 219 } 220 221 #ifdef COMPAT_43 222 owait(p, uap, retval) 223 struct proc *p; 224 register struct args { 225 int pid; 226 int *status; 227 int options; 228 struct rusage *rusage; 229 int compat; 230 } *uap; 231 int *retval; 232 { 233 234 if ((p->p_regs[PS] & PSL_ALLCC) != PSL_ALLCC) { 235 uap->options = 0; 236 uap->rusage = 0; 237 } else { 238 uap->options = p->p_regs[R0]; 239 uap->rusage = (struct rusage *)p->p_regs[R1]; 240 } 241 uap->pid = WAIT_ANY; 242 uap->status = 0; 243 uap->compat = 1; 244 return (wait1(p, uap, retval)); 245 } 246 247 wait4(p, uap, retval) 248 struct proc *p; 249 struct args { 250 int pid; 251 int *status; 252 int options; 253 struct rusage *rusage; 254 int compat; 255 } *uap; 256 int *retval; 257 { 258 259 uap->compat = 0; 260 return (wait1(p, uap, retval)); 261 } 262 #else 263 #define wait1 wait4 264 #endif 265 266 /* 267 * Wait: check child processes to see if any have exited, 268 * stopped under trace, or (optionally) stopped by a signal. 269 * Pass back status and deallocate exited child's proc structure. 270 */ 271 wait1(q, uap, retval) 272 register struct proc *q; 273 register struct args { 274 int pid; 275 int *status; 276 int options; 277 struct rusage *rusage; 278 #ifdef COMPAT_43 279 int compat; 280 #endif 281 } *uap; 282 int retval[]; 283 { 284 register int nfound; 285 register struct proc *p; 286 int status, error; 287 288 if (uap->pid == 0) 289 uap->pid = -q->p_pgid; 290 #ifdef notyet 291 if (uap->options &~ (WUNTRACED|WNOHANG)) 292 return (EINVAL); 293 #endif 294 loop: 295 nfound = 0; 296 for (p = q->p_cptr; p; p = p->p_osptr) { 297 if (uap->pid != WAIT_ANY && 298 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 299 continue; 300 nfound++; 301 if (p->p_stat == SZOMB) { 302 retval[0] = p->p_pid; 303 #ifdef COMPAT_43 304 if (uap->compat) 305 retval[1] = p->p_xstat; 306 else 307 #endif 308 if (uap->status) { 309 status = p->p_xstat; /* convert to int */ 310 if (error = copyout((caddr_t)&status, 311 (caddr_t)uap->status, sizeof(status))) 312 return (error); 313 } 314 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 315 (caddr_t)uap->rusage, sizeof (struct rusage)))) 316 return (error); 317 p->p_xstat = 0; 318 ruadd(&q->p_stats->p_cru, p->p_ru); 319 FREE(p->p_ru, M_ZOMBIE); 320 if (--p->p_cred->p_refcnt == 0) { 321 crfree(p->p_cred->pc_ucred); 322 FREE(p->p_cred, M_SUBPROC); 323 } 324 325 /* 326 * Finally finished with old proc entry. 327 * Unlink it from its process group and free it. 328 */ 329 leavepgrp(p); 330 if (*p->p_prev = p->p_nxt) /* off zombproc */ 331 p->p_nxt->p_prev = p->p_prev; 332 if (q = p->p_ysptr) 333 q->p_osptr = p->p_osptr; 334 if (q = p->p_osptr) 335 q->p_ysptr = p->p_ysptr; 336 if ((q = p->p_pptr)->p_cptr == p) 337 q->p_cptr = p->p_osptr; 338 339 /* 340 * Give machine-dependent layer a chance 341 * to free anything that cpu_exit couldn't 342 * release while still running in process context. 343 */ 344 cpu_wait(p); 345 FREE(p, M_PROC); 346 nprocs--; 347 return (0); 348 } 349 if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 && 350 (p->p_flag & STRC || uap->options & WUNTRACED)) { 351 p->p_flag |= SWTED; 352 retval[0] = p->p_pid; 353 #ifdef COMPAT_43 354 if (uap->compat) { 355 retval[1] = W_STOPCODE(p->p_xstat); 356 error = 0; 357 } else 358 #endif 359 if (uap->status) { 360 status = W_STOPCODE(p->p_xstat); 361 error = copyout((caddr_t)&status, 362 (caddr_t)uap->status, sizeof(status)); 363 } else 364 error = 0; 365 return (error); 366 } 367 } 368 if (nfound == 0) 369 return (ECHILD); 370 if (uap->options & WNOHANG) { 371 retval[0] = 0; 372 return (0); 373 } 374 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 375 return (error); 376 goto loop; 377 } 378