kernel/exit.c

/* */
This source file includes following definitions.
generate
send_sig
notify_parent
release
bad_task_ptr
audit_ptree
session_of_pgrp
kill_pg
kill_sl
kill_proc
sys_kill
is_orphaned_pgrp
has_stopped_jobs
forget_original_parent
__exit_files
exit_files
__exit_fs
exit_fs
__exit_sighand
exit_sighand
exit_mm
exit_notify
do_exit
sys_exit
sys_wait4
sys_waitpid
   1 /*
   2  *  linux/kernel/exit.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6 
   7 #undef DEBUG_PROC_TREE
   8 
   9 #include <linux/wait.h>
  10 #include <linux/errno.h>
  11 #include <linux/signal.h>
  12 #include <linux/sched.h>
  13 #include <linux/kernel.h>
  14 #include <linux/resource.h>
  15 #include <linux/mm.h>
  16 #include <linux/tty.h>
  17 #include <linux/malloc.h>
  18 
  19 #include <asm/segment.h>
  20 extern void sem_exit (void);
  21 extern void acct_process (long exitcode);
  22 extern void kerneld_exit(void);
  23 
  24 int getrusage(struct task_struct *, int, struct rusage *);
  25 
  26 static int generate(unsigned long sig, struct task_struct * p)
     /*  */
  27 {
  28         unsigned long mask = 1 << (sig-1);
  29         struct sigaction * sa = sig + p->sig->action - 1;
  30 
  31         /* always generate signals for traced processes ??? */
  32         if (!(p->flags & PF_PTRACED)) {
  33                 /* don't bother with ignored signals (but SIGCHLD is special) */
  34                 if (sa->sa_handler == SIG_IGN && sig != SIGCHLD)
  35                         return 0;
  36                 /* some signals are ignored by default.. (but SIGCONT already did its deed) */
  37                 if ((sa->sa_handler == SIG_DFL) &&
  38                     (sig == SIGCONT || sig == SIGCHLD || sig == SIGWINCH || sig == SIGURG))
  39                         return 0;
  40         }
  41         p->signal |= mask;
  42         if (p->state == TASK_INTERRUPTIBLE && (p->signal & ~p->blocked))
  43                 wake_up_process(p);
  44         return 1;
  45 }
  46 
  47 int send_sig(unsigned long sig,struct task_struct * p,int priv)
     /*  */
  48 {
  49         if (!p || sig > 32)
  50                 return -EINVAL;
  51         if (!priv && ((sig != SIGCONT) || (current->session != p->session)) &&
  52             (current->euid != p->euid) && (current->euid != p->uid) && !suser())
  53                 return -EPERM;
  54         if (!sig)
  55                 return 0;
  56         /*
  57          * Forget it if the process is already zombie'd.
  58          */
  59         if (!p->sig)
  60                 return 0;
  61         if ((sig == SIGKILL) || (sig == SIGCONT)) {
  62                 if (p->state == TASK_STOPPED)
  63                         wake_up_process(p);
  64                 p->exit_code = 0;
  65                 p->signal &= ~( (1<<(SIGSTOP-1)) | (1<<(SIGTSTP-1)) |
  66                                 (1<<(SIGTTIN-1)) | (1<<(SIGTTOU-1)) );
  67         }
  68         if (sig == SIGSTOP || sig == SIGTSTP || sig == SIGTTIN || sig == SIGTTOU)
  69                 p->signal &= ~(1<<(SIGCONT-1));
  70         /* Actually generate the signal */
  71         generate(sig,p);
  72         return 0;
  73 }
  74 
  75 void notify_parent(struct task_struct * tsk)
     /*  */
  76 {
  77         if (tsk->p_pptr == task[smp_num_cpus])          /* Init */
  78                 tsk->exit_signal = SIGCHLD;
  79         send_sig(tsk->exit_signal, tsk->p_pptr, 1);
  80         wake_up_interruptible(&tsk->p_pptr->wait_chldexit);
  81 }
  82 
  83 void release(struct task_struct * p)
     /*  */
  84 {
  85         int i;
  86 
  87         if (!p)
  88                 return;
  89         if (p == current) {
  90                 printk("task releasing itself\n");
  91                 return;
  92         }
  93         for (i=1 ; i<NR_TASKS ; i++)
  94                 if (task[i] == p) {
  95                         nr_tasks--;
  96                         task[i] = NULL;
  97                         REMOVE_LINKS(p);
  98                         release_thread(p);
  99                         if (STACK_MAGIC != *(unsigned long *)p->kernel_stack_page)
 100                                 printk(KERN_ALERT "release: %s kernel stack corruption. Aiee\n", p->comm);
 101                         free_kernel_stack(p->kernel_stack_page);
 102                         current->cmin_flt += p->min_flt + p->cmin_flt;
 103                         current->cmaj_flt += p->maj_flt + p->cmaj_flt;
 104                         current->cnswap += p->nswap + p->cnswap;
 105                         kfree(p);
 106                         return;
 107                 }
 108         panic("trying to release non-existent task");
 109 }
 110 
 111 #ifdef DEBUG_PROC_TREE
 112 /*
 113  * Check to see if a task_struct pointer is present in the task[] array
 114  * Return 0 if found, and 1 if not found.
 115  */
 116 int bad_task_ptr(struct task_struct *p)
     /*  */
 117 {
 118         int     i;
 119 
 120         if (!p)
 121                 return 0;
 122         for (i=0 ; i<NR_TASKS ; i++)
 123                 if (task[i] == p)
 124                         return 0;
 125         return 1;
 126 }
 127         
 128 /*
 129  * This routine scans the pid tree and makes sure the rep invariant still
 130  * holds.  Used for debugging only, since it's very slow....
 131  *
 132  * It looks a lot scarier than it really is.... we're doing nothing more
 133  * than verifying the doubly-linked list found in p_ysptr and p_osptr, 
 134  * and checking it corresponds with the process tree defined by p_cptr and 
 135  * p_pptr;
 136  */
 137 void audit_ptree(void)
     /*  */
 138 {
 139         int     i;
 140 
 141         for (i=1 ; i<NR_TASKS ; i++) {
 142                 if (!task[i])
 143                         continue;
 144                 if (bad_task_ptr(task[i]->p_pptr))
 145                         printk("Warning, pid %d's parent link is bad\n",
 146                                 task[i]->pid);
 147                 if (bad_task_ptr(task[i]->p_cptr))
 148                         printk("Warning, pid %d's child link is bad\n",
 149                                 task[i]->pid);
 150                 if (bad_task_ptr(task[i]->p_ysptr))
 151                         printk("Warning, pid %d's ys link is bad\n",
 152                                 task[i]->pid);
 153                 if (bad_task_ptr(task[i]->p_osptr))
 154                         printk("Warning, pid %d's os link is bad\n",
 155                                 task[i]->pid);
 156                 if (task[i]->p_pptr == task[i])
 157                         printk("Warning, pid %d parent link points to self\n",
 158                                 task[i]->pid);
 159                 if (task[i]->p_cptr == task[i])
 160                         printk("Warning, pid %d child link points to self\n",
 161                                 task[i]->pid);
 162                 if (task[i]->p_ysptr == task[i])
 163                         printk("Warning, pid %d ys link points to self\n",
 164                                 task[i]->pid);
 165                 if (task[i]->p_osptr == task[i])
 166                         printk("Warning, pid %d os link points to self\n",
 167                                 task[i]->pid);
 168                 if (task[i]->p_osptr) {
 169                         if (task[i]->p_pptr != task[i]->p_osptr->p_pptr)
 170                                 printk(
 171                         "Warning, pid %d older sibling %d parent is %d\n",
 172                                 task[i]->pid, task[i]->p_osptr->pid,
 173                                 task[i]->p_osptr->p_pptr->pid);
 174                         if (task[i]->p_osptr->p_ysptr != task[i])
 175                                 printk(
 176                 "Warning, pid %d older sibling %d has mismatched ys link\n",
 177                                 task[i]->pid, task[i]->p_osptr->pid);
 178                 }
 179                 if (task[i]->p_ysptr) {
 180                         if (task[i]->p_pptr != task[i]->p_ysptr->p_pptr)
 181                                 printk(
 182                         "Warning, pid %d younger sibling %d parent is %d\n",
 183                                 task[i]->pid, task[i]->p_osptr->pid,
 184                                 task[i]->p_osptr->p_pptr->pid);
 185                         if (task[i]->p_ysptr->p_osptr != task[i])
 186                                 printk(
 187                 "Warning, pid %d younger sibling %d has mismatched os link\n",
 188                                 task[i]->pid, task[i]->p_ysptr->pid);
 189                 }
 190                 if (task[i]->p_cptr) {
 191                         if (task[i]->p_cptr->p_pptr != task[i])
 192                                 printk(
 193                         "Warning, pid %d youngest child %d has mismatched parent link\n",
 194                                 task[i]->pid, task[i]->p_cptr->pid);
 195                         if (task[i]->p_cptr->p_ysptr)
 196                                 printk(
 197                         "Warning, pid %d youngest child %d has non-NULL ys link\n",
 198                                 task[i]->pid, task[i]->p_cptr->pid);
 199                 }
 200         }
 201 }
 202 #endif /* DEBUG_PROC_TREE */
 203 
 204 /*
 205  * This checks not only the pgrp, but falls back on the pid if no
 206  * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
 207  * without this...
 208  */
 209 int session_of_pgrp(int pgrp)
     /*  */
 210 {
 211         struct task_struct *p;
 212         int fallback;
 213 
 214         fallback = -1;
 215         for_each_task(p) {
 216                 if (p->session <= 0)
 217                         continue;
 218                 if (p->pgrp == pgrp)
 219                         return p->session;
 220                 if (p->pid == pgrp)
 221                         fallback = p->session;
 222         }
 223         return fallback;
 224 }
 225 
 226 /*
 227  * kill_pg() sends a signal to a process group: this is what the tty
 228  * control characters do (^C, ^Z etc)
 229  */
 230 int kill_pg(int pgrp, int sig, int priv)
     /*  */
 231 {
 232         struct task_struct *p;
 233         int err,retval = -ESRCH;
 234         int found = 0;
 235 
 236         if (sig<0 || sig>32 || pgrp<=0)
 237                 return -EINVAL;
 238         for_each_task(p) {
 239                 if (p->pgrp == pgrp) {
 240                         if ((err = send_sig(sig,p,priv)) != 0)
 241                                 retval = err;
 242                         else
 243                                 found++;
 244                 }
 245         }
 246         return(found ? 0 : retval);
 247 }
 248 
 249 /*
 250  * kill_sl() sends a signal to the session leader: this is used
 251  * to send SIGHUP to the controlling process of a terminal when
 252  * the connection is lost.
 253  */
 254 int kill_sl(int sess, int sig, int priv)
     /*  */
 255 {
 256         struct task_struct *p;
 257         int err,retval = -ESRCH;
 258         int found = 0;
 259 
 260         if (sig<0 || sig>32 || sess<=0)
 261                 return -EINVAL;
 262         for_each_task(p) {
 263                 if (p->session == sess && p->leader) {
 264                         if ((err = send_sig(sig,p,priv)) != 0)
 265                                 retval = err;
 266                         else
 267                                 found++;
 268                 }
 269         }
 270         return(found ? 0 : retval);
 271 }
 272 
 273 int kill_proc(int pid, int sig, int priv)
     /*  */
 274 {
 275         struct task_struct *p;
 276 
 277         if (sig<0 || sig>32)
 278                 return -EINVAL;
 279         for_each_task(p) {
 280                 if (p && p->pid == pid)
 281                         return send_sig(sig,p,priv);
 282         }
 283         return(-ESRCH);
 284 }
 285 
 286 /*
 287  * POSIX specifies that kill(-1,sig) is unspecified, but what we have
 288  * is probably wrong.  Should make it like BSD or SYSV.
 289  */
 290 asmlinkage int sys_kill(int pid,int sig)
     /*  */
 291 {
 292         int err, retval = 0, count = 0;
 293 
 294         if (!pid)
 295                 return(kill_pg(current->pgrp,sig,0));
 296         if (pid == -1) {
 297                 struct task_struct * p;
 298                 for_each_task(p) {
 299                         if (p->pid > 1 && p != current) {
 300                                 ++count;
 301                                 if ((err = send_sig(sig,p,0)) != -EPERM)
 302                                         retval = err;
 303                         }
 304                 }
 305                 return(count ? retval : -ESRCH);
 306         }
 307         if (pid < 0) 
 308                 return(kill_pg(-pid,sig,0));
 309         /* Normal kill */
 310         return(kill_proc(pid,sig,0));
 311 }
 312 
 313 /*
 314  * Determine if a process group is "orphaned", according to the POSIX
 315  * definition in 2.2.2.52.  Orphaned process groups are not to be affected
 316  * by terminal-generated stop signals.  Newly orphaned process groups are 
 317  * to receive a SIGHUP and a SIGCONT.
 318  * 
 319  * "I ask you, have you ever known what it is to be an orphan?"
 320  */
 321 int is_orphaned_pgrp(int pgrp)
     /*  */
 322 {
 323         struct task_struct *p;
 324 
 325         for_each_task(p) {
 326                 if ((p->pgrp != pgrp) || 
 327                     (p->state == TASK_ZOMBIE) ||
 328                     (p->p_pptr->pid == 1))
 329                         continue;
 330                 if ((p->p_pptr->pgrp != pgrp) &&
 331                     (p->p_pptr->session == p->session))
 332                         return 0;
 333         }
 334         return(1);      /* (sighing) "Often!" */
 335 }
 336 
 337 static inline int has_stopped_jobs(int pgrp)
     /*  */
 338 {
 339         struct task_struct * p;
 340 
 341         for_each_task(p) {
 342                 if (p->pgrp != pgrp)
 343                         continue;
 344                 if (p->state == TASK_STOPPED)
 345                         return(1);
 346         }
 347         return(0);
 348 }
 349 
 350 static inline void forget_original_parent(struct task_struct * father)
     /*  */
 351 {
 352         struct task_struct * p;
 353 
 354         for_each_task(p) {
 355                 if (p->p_opptr == father)
 356                         if (task[smp_num_cpus]) /* init */
 357                                 p->p_opptr = task[smp_num_cpus];
 358                         else
 359                                 p->p_opptr = task[0];
 360         }
 361 }
 362 
 363 static inline void __exit_files(struct task_struct *tsk)
     /*  */
 364 {
 365         struct files_struct * files = tsk->files;
 366 
 367         if (files) {
 368                 tsk->files = NULL;
 369                 if (!--files->count) {
 370                         int i;
 371                         for (i=0 ; i<NR_OPEN ; i++) {
 372                                 struct file * filp = files->fd[i];
 373                                 if (!filp)
 374                                         continue;
 375                                 files->fd[i] = NULL;
 376                                 close_fp(filp);
 377                         }
 378                         kfree(files);
 379                 }
 380         }
 381 }
 382 
 383 void exit_files(struct task_struct *tsk)
     /*  */
 384 {
 385   __exit_files(tsk);
 386 }
 387 
 388 static inline void __exit_fs(struct task_struct *tsk)
     /*  */
 389 {
 390         struct fs_struct * fs = tsk->fs;
 391 
 392         if (fs) {
 393                 tsk->fs = NULL;
 394                 if (!--fs->count) {
 395                         iput(fs->root);
 396                         iput(fs->pwd);
 397                         kfree(fs);
 398                 }
 399         }
 400 }
 401 
 402 void exit_fs(struct task_struct *tsk)
     /*  */
 403 {
 404   __exit_fs(tsk);
 405 }
 406 
 407 static inline void __exit_sighand(struct task_struct *tsk)
     /*  */
 408 {
 409         struct signal_struct * sig = tsk->sig;
 410 
 411         if (sig) {
 412                 tsk->sig = NULL;
 413                 if (!--sig->count) {
 414                         kfree(sig);
 415                 }
 416         }
 417 }
 418 
 419 void exit_sighand(struct task_struct *tsk)
     /*  */
 420 {
 421   __exit_sighand(tsk);
 422 }
 423 
 424 static inline void exit_mm(void)
     /*  */
 425 {
 426         struct mm_struct * mm = current->mm;
 427 
 428         current->swappable = 0;
 429         if (mm) {
 430                 if (!--mm->count) {
 431                         exit_mmap(mm);
 432                         free_page_tables(current);
 433                         kfree(mm);
 434                 }
 435                 current->mm = NULL;
 436         }
 437 }
 438 
 439 /* 
 440  * Send signals to all our closest relatives so that they know
 441  * to properly mourn us..
 442  */
 443 static void exit_notify(void)
     /*  */
 444 {
 445         struct task_struct * p;
 446 
 447         forget_original_parent(current);
 448         /* 
 449          * Check to see if any process groups have become orphaned
 450          * as a result of our exiting, and if they have any stopped
 451          * jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
 452          *
 453          * Case i: Our father is in a different pgrp than we are
 454          * and we were the only connection outside, so our pgrp
 455          * is about to become orphaned.
 456          */
 457         if ((current->p_pptr->pgrp != current->pgrp) &&
 458             (current->p_pptr->session == current->session) &&
 459             is_orphaned_pgrp(current->pgrp) &&
 460             has_stopped_jobs(current->pgrp)) {
 461                 kill_pg(current->pgrp,SIGHUP,1);
 462                 kill_pg(current->pgrp,SIGCONT,1);
 463         }
 464         /* Let father know we died */
 465         notify_parent(current);
 466         
 467         /*
 468          * This loop does two things:
 469          * 
 470          * A.  Make init inherit all the child processes
 471          * B.  Check to see if any process groups have become orphaned
 472          *      as a result of our exiting, and if they have any stopped
 473          *      jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
 474          */
 475         while ((p = current->p_cptr) != NULL) {
 476                 current->p_cptr = p->p_osptr;
 477                 p->p_ysptr = NULL;
 478                 p->flags &= ~(PF_PTRACED|PF_TRACESYS);
 479                 if (task[smp_num_cpus] && task[smp_num_cpus] != current) /* init */
 480                         p->p_pptr = task[smp_num_cpus];
 481                 else
 482                         p->p_pptr = task[0];
 483                 p->p_osptr = p->p_pptr->p_cptr;
 484                 p->p_osptr->p_ysptr = p;
 485                 p->p_pptr->p_cptr = p;
 486                 if (p->state == TASK_ZOMBIE)
 487                         notify_parent(p);
 488                 /*
 489                  * process group orphan check
 490                  * Case ii: Our child is in a different pgrp 
 491                  * than we are, and it was the only connection
 492                  * outside, so the child pgrp is now orphaned.
 493                  */
 494                 if ((p->pgrp != current->pgrp) &&
 495                     (p->session == current->session) &&
 496                     is_orphaned_pgrp(p->pgrp) &&
 497                     has_stopped_jobs(p->pgrp)) {
 498                         kill_pg(p->pgrp,SIGHUP,1);
 499                         kill_pg(p->pgrp,SIGCONT,1);
 500                 }
 501         }
 502         if (current->leader)
 503                 disassociate_ctty(1);
 504 }
 505 
 506 NORET_TYPE void do_exit(long code)
     /*  */
 507 {
 508         if (intr_count) {
 509                 printk("Aiee, killing interrupt handler\n");
 510                 intr_count = 0;
 511         }
 512 fake_volatile:
 513         acct_process(code);
 514         current->flags |= PF_EXITING;
 515         del_timer(&current->real_timer);
 516         sem_exit();
 517         kerneld_exit();
 518         exit_mm();
 519         __exit_files(current);
 520         __exit_fs(current);
 521         __exit_sighand(current);
 522         exit_thread();
 523         current->state = TASK_ZOMBIE;
 524         current->exit_code = code;
 525         exit_notify();
 526 #ifdef DEBUG_PROC_TREE
 527         audit_ptree();
 528 #endif
 529         if (current->exec_domain && current->exec_domain->use_count)
 530                 (*current->exec_domain->use_count)--;
 531         if (current->binfmt && current->binfmt->use_count)
 532                 (*current->binfmt->use_count)--;
 533         schedule();
 534 /*
 535  * In order to get rid of the "volatile function does return" message
 536  * I did this little loop that confuses gcc to think do_exit really
 537  * is volatile. In fact it's schedule() that is volatile in some
 538  * circumstances: when current->state = ZOMBIE, schedule() never
 539  * returns.
 540  *
 541  * In fact the natural way to do all this is to have the label and the
 542  * goto right after each other, but I put the fake_volatile label at
 543  * the start of the function just in case something /really/ bad
 544  * happens, and the schedule returns. This way we can try again. I'm
 545  * not paranoid: it's just that everybody is out to get me.
 546  */
 547         goto fake_volatile;
 548 }
 549 
 550 asmlinkage int sys_exit(int error_code)
     /*  */
 551 {
 552         do_exit((error_code&0xff)<<8);
 553 }
 554 
 555 asmlinkage int sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
     /*  */
 556 {
 557         int flag, retval;
 558         struct wait_queue wait = { current, NULL };
 559         struct task_struct *p;
 560 
 561         if (stat_addr) {
 562                 flag = verify_area(VERIFY_WRITE, stat_addr, sizeof(*stat_addr));
 563                 if (flag)
 564                         return flag;
 565         }
 566         if (ru) {
 567                 flag = verify_area(VERIFY_WRITE, ru, sizeof(*ru));
 568                 if (flag)
 569                         return flag;
 570         }
 571         add_wait_queue(&current->wait_chldexit,&wait);
 572 repeat:
 573         flag=0;
 574         for (p = current->p_cptr ; p ; p = p->p_osptr) {
 575                 if (pid>0) {
 576                         if (p->pid != pid)
 577                                 continue;
 578                 } else if (!pid) {
 579                         if (p->pgrp != current->pgrp)
 580                                 continue;
 581                 } else if (pid != -1) {
 582                         if (p->pgrp != -pid)
 583                                 continue;
 584                 }
 585                 /* wait for cloned processes iff the __WCLONE flag is set */
 586                 if ((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
 587                         continue;
 588                 flag = 1;
 589                 switch (p->state) {
 590                         case TASK_STOPPED:
 591                                 if (!p->exit_code)
 592                                         continue;
 593                                 if (!(options & WUNTRACED) && !(p->flags & PF_PTRACED))
 594                                         continue;
 595                                 if (ru != NULL)
 596                                         getrusage(p, RUSAGE_BOTH, ru);
 597                                 if (stat_addr)
 598                                         put_user((p->exit_code << 8) | 0x7f,
 599                                                 stat_addr);
 600                                 p->exit_code = 0;
 601                                 retval = p->pid;
 602                                 goto end_wait4;
 603                         case TASK_ZOMBIE:
 604                                 current->cutime += p->utime + p->cutime;
 605                                 current->cstime += p->stime + p->cstime;
 606                                 if (ru != NULL)
 607                                         getrusage(p, RUSAGE_BOTH, ru);
 608                                 if (stat_addr)
 609                                         put_user(p->exit_code, stat_addr);
 610                                 retval = p->pid;
 611                                 if (p->p_opptr != p->p_pptr) {
 612                                         REMOVE_LINKS(p);
 613                                         p->p_pptr = p->p_opptr;
 614                                         SET_LINKS(p);
 615                                         notify_parent(p);
 616                                 } else
 617                                         release(p);
 618 #ifdef DEBUG_PROC_TREE
 619                                 audit_ptree();
 620 #endif
 621                                 goto end_wait4;
 622                         default:
 623                                 continue;
 624                 }
 625         }
 626         if (flag) {
 627                 retval = 0;
 628                 if (options & WNOHANG)
 629                         goto end_wait4;
 630                 current->state=TASK_INTERRUPTIBLE;
 631                 schedule();
 632                 current->signal &= ~(1<<(SIGCHLD-1));
 633                 retval = -ERESTARTSYS;
 634                 if (current->signal & ~current->blocked)
 635                         goto end_wait4;
 636                 goto repeat;
 637         }
 638         retval = -ECHILD;
 639 end_wait4:
 640         remove_wait_queue(&current->wait_chldexit,&wait);
 641         return retval;
 642 }
 643 
 644 #ifndef __alpha__
 645 
 646 /*
 647  * sys_waitpid() remains for compatibility. waitpid() should be
 648  * implemented by calling sys_wait4() from libc.a.
 649  */
 650 asmlinkage int sys_waitpid(pid_t pid,unsigned int * stat_addr, int options)
     /*  */
 651 {
 652         return sys_wait4(pid, stat_addr, options, NULL);
 653 }
 654 
 655 #endif
/* */
root/kernel/exit.c

DEFINITIONS
