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 7.40 (Berkeley) 02/13/92 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 #ifdef KTRACE 136 /* 137 * release trace file 138 */ 139 p->p_traceflag = 0; /* don't trace the vrele() */ 140 if (p->p_tracep) 141 vrele(p->p_tracep); 142 #endif 143 /* 144 * Clear curproc after we've done all operations 145 * that could block, and before tearing down 146 * the rest of the process state. 147 */ 148 curproc = NULL; 149 if (--p->p_limit->p_refcnt == 0) 150 FREE(p->p_limit, M_SUBPROC); 151 152 /* 153 * Remove proc from allproc queue and pidhash chain. 154 * Place onto zombproc. Unlink from parent's child list. 155 */ 156 if (*p->p_prev = p->p_nxt) 157 p->p_nxt->p_prev = p->p_prev; 158 if (p->p_nxt = zombproc) 159 p->p_nxt->p_prev = &p->p_nxt; 160 p->p_prev = &zombproc; 161 zombproc = p; 162 p->p_stat = SZOMB; 163 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 164 if (*pp == p) { 165 *pp = p->p_hash; 166 goto done; 167 } 168 panic("exit"); 169 done: 170 171 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 172 wakeup((caddr_t) initproc); 173 for (q = p->p_cptr; q != NULL; q = nq) { 174 nq = q->p_osptr; 175 if (nq != NULL) 176 nq->p_ysptr = NULL; 177 if (initproc->p_cptr) 178 initproc->p_cptr->p_ysptr = q; 179 q->p_osptr = initproc->p_cptr; 180 q->p_ysptr = NULL; 181 initproc->p_cptr = q; 182 183 q->p_pptr = initproc; 184 /* 185 * Traced processes are killed 186 * since their existence means someone is screwing up. 187 */ 188 if (q->p_flag&STRC) { 189 q->p_flag &= ~STRC; 190 psignal(q, SIGKILL); 191 } 192 } 193 p->p_cptr = NULL; 194 195 /* 196 * Save exit status and final rusage info, 197 * adding in child rusage info and self times. 198 */ 199 p->p_xstat = rv; 200 *p->p_ru = p->p_stats->p_ru; 201 p->p_ru->ru_stime = p->p_stime; 202 p->p_ru->ru_utime = p->p_utime; 203 ruadd(p->p_ru, &p->p_stats->p_cru); 204 205 /* 206 * Notify parent that we're gone. 207 */ 208 psignal(p->p_pptr, SIGCHLD); 209 wakeup((caddr_t)p->p_pptr); 210 #if defined(tahoe) 211 /* move this to cpu_exit */ 212 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 213 #endif 214 /* 215 * Finally, call machine-dependent code to release the remaining 216 * resources including address space, the kernel stack and pcb. 217 * The address space is released by "vmspace_free(p->p_vmspace)"; 218 * This is machine-dependent, as we may have to change stacks 219 * or ensure that the current one isn't reallocated before we 220 * finish. cpu_exit will end with a call to swtch(), finishing 221 * our execution (pun intended). 222 */ 223 cpu_exit(p); 224 /* NOTREACHED */ 225 } 226 227 #ifdef COMPAT_43 228 owait(p, uap, retval) 229 struct proc *p; 230 register struct args { 231 int pid; 232 int *status; 233 int options; 234 struct rusage *rusage; 235 int compat; 236 } *uap; 237 int *retval; 238 { 239 240 #ifdef PSL_ALLCC 241 if ((p->p_md.md_regs[PS] & PSL_ALLCC) != PSL_ALLCC) { 242 uap->options = 0; 243 uap->rusage = 0; 244 } else { 245 uap->options = p->p_md.md_regs[R0]; 246 uap->rusage = (struct rusage *)p->p_md.md_regs[R1]; 247 } 248 #else 249 uap->options = 0; 250 uap->rusage = 0; 251 #endif 252 uap->pid = WAIT_ANY; 253 uap->status = 0; 254 uap->compat = 1; 255 return (wait1(p, uap, retval)); 256 } 257 258 wait4(p, uap, retval) 259 struct proc *p; 260 struct args { 261 int pid; 262 int *status; 263 int options; 264 struct rusage *rusage; 265 int compat; 266 } *uap; 267 int *retval; 268 { 269 270 uap->compat = 0; 271 return (wait1(p, uap, retval)); 272 } 273 #else 274 #define wait1 wait4 275 #endif 276 277 /* 278 * Wait: check child processes to see if any have exited, 279 * stopped under trace, or (optionally) stopped by a signal. 280 * Pass back status and deallocate exited child's proc structure. 281 */ 282 wait1(q, uap, retval) 283 register struct proc *q; 284 register struct args { 285 int pid; 286 int *status; 287 int options; 288 struct rusage *rusage; 289 #ifdef COMPAT_43 290 int compat; 291 #endif 292 } *uap; 293 int retval[]; 294 { 295 register int nfound; 296 register struct proc *p; 297 int status, error; 298 299 if (uap->pid == 0) 300 uap->pid = -q->p_pgid; 301 #ifdef notyet 302 if (uap->options &~ (WUNTRACED|WNOHANG)) 303 return (EINVAL); 304 #endif 305 loop: 306 nfound = 0; 307 for (p = q->p_cptr; p; p = p->p_osptr) { 308 if (uap->pid != WAIT_ANY && 309 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 310 continue; 311 nfound++; 312 if (p->p_stat == SZOMB) { 313 retval[0] = p->p_pid; 314 #ifdef COMPAT_43 315 if (uap->compat) 316 retval[1] = p->p_xstat; 317 else 318 #endif 319 if (uap->status) { 320 status = p->p_xstat; /* convert to int */ 321 if (error = copyout((caddr_t)&status, 322 (caddr_t)uap->status, sizeof(status))) 323 return (error); 324 } 325 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 326 (caddr_t)uap->rusage, sizeof (struct rusage)))) 327 return (error); 328 p->p_xstat = 0; 329 ruadd(&q->p_stats->p_cru, p->p_ru); 330 FREE(p->p_ru, M_ZOMBIE); 331 if (--p->p_cred->p_refcnt == 0) { 332 crfree(p->p_cred->pc_ucred); 333 FREE(p->p_cred, M_SUBPROC); 334 } 335 336 /* 337 * Finally finished with old proc entry. 338 * Unlink it from its process group and free it. 339 */ 340 leavepgrp(p); 341 if (*p->p_prev = p->p_nxt) /* off zombproc */ 342 p->p_nxt->p_prev = p->p_prev; 343 if (q = p->p_ysptr) 344 q->p_osptr = p->p_osptr; 345 if (q = p->p_osptr) 346 q->p_ysptr = p->p_ysptr; 347 if ((q = p->p_pptr)->p_cptr == p) 348 q->p_cptr = p->p_osptr; 349 350 /* 351 * Give machine-dependent layer a chance 352 * to free anything that cpu_exit couldn't 353 * release while still running in process context. 354 */ 355 cpu_wait(p); 356 FREE(p, M_PROC); 357 nprocs--; 358 return (0); 359 } 360 if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 && 361 (p->p_flag & STRC || uap->options & WUNTRACED)) { 362 p->p_flag |= SWTED; 363 retval[0] = p->p_pid; 364 #ifdef COMPAT_43 365 if (uap->compat) { 366 retval[1] = W_STOPCODE(p->p_xstat); 367 error = 0; 368 } else 369 #endif 370 if (uap->status) { 371 status = W_STOPCODE(p->p_xstat); 372 error = copyout((caddr_t)&status, 373 (caddr_t)uap->status, sizeof(status)); 374 } else 375 error = 0; 376 return (error); 377 } 378 } 379 if (nfound == 0) 380 return (ECHILD); 381 if (uap->options & WNOHANG) { 382 retval[0] = 0; 383 return (0); 384 } 385 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 386 return (error); 387 goto loop; 388 } 389