1 /* vi: set sw=4 ts=4: */
3 * Mini init implementation for busybox
5 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
6 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 * Adjusted by so many folks, it's impossible to keep track.
9 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
14 #include <sys/reboot.h>
15 #include <sys/syslog.h>
17 #define INIT_BUFFS_SIZE 256
18 #define CONSOLE_NAME_SIZE 32
19 #define MAXENV 16 /* Number of env. vars */
22 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
23 * before processes are spawned to set core file size as unlimited.
24 * This is for debugging only. Don't use this is production, unless
25 * you want core dumps lying about....
27 #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
28 #include <sys/resource.h>
30 #define INITTAB "/etc/inittab" /* inittab file location */
32 #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
35 /* Allowed init action types */
38 #define ASKFIRST 0x004
41 #define CTRLALTDEL 0x020
42 #define SHUTDOWN 0x040
45 #define STR_SYSINIT "\x01"
46 #define STR_RESPAWN "\x02"
47 #define STR_ASKFIRST "\x04"
48 #define STR_WAIT "\x08"
49 #define STR_ONCE "\x10"
50 #define STR_CTRLALTDEL "\x20"
51 #define STR_SHUTDOWN "\x40"
52 #define STR_RESTART "\x80"
54 /* Set up a linked list of init_actions, to be read from inittab */
56 struct init_action *next;
59 char terminal[CONSOLE_NAME_SIZE];
60 char command[INIT_BUFFS_SIZE];
63 /* Static variables */
64 static struct init_action *init_action_list = NULL;
66 static const char *log_console = VC_5;
67 static sig_atomic_t got_cont = 0;
73 #if ENABLE_FEATURE_EXTRA_QUIET
76 MAYBE_CONSOLE = L_CONSOLE,
79 #ifndef RB_HALT_SYSTEM
80 RB_HALT_SYSTEM = 0xcdef0123, /* FIXME: this overflows enum */
81 RB_ENABLE_CAD = 0x89abcdef,
83 RB_POWER_OFF = 0x4321fedc,
84 RB_AUTOBOOT = 0x01234567,
88 static const char *const environment[] = {
96 /* Function prototypes */
97 static void delete_init_action(struct init_action *a);
98 static void halt_reboot_pwoff(int sig) ATTRIBUTE_NORETURN;
100 /* TODO: move to libbb? */
101 static int waitfor(pid_t runpid)
103 return safe_waitpid(runpid, NULL, 0);
106 static void loop_forever(void) ATTRIBUTE_NORETURN;
107 static void loop_forever(void)
113 /* Print a message to the specified device.
114 * Device may be bitwise-or'd from L_LOG | L_CONSOLE */
115 #define messageD(...) do { if (ENABLE_DEBUG_INIT) message(__VA_ARGS__); } while (0)
116 static void message(int device, const char *fmt, ...)
117 __attribute__ ((format(printf, 2, 3)));
118 static void message(int device, const char *fmt, ...)
120 static int log_fd = -1;
126 va_start(arguments, fmt);
127 vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments);
129 msg[sizeof(msg) - 2] = '\0';
132 if (ENABLE_FEATURE_INIT_SYSLOG) {
133 /* Log the message to syslogd */
134 if (device & L_LOG) {
136 openlog(applet_name, 0, LOG_DAEMON);
137 syslog(LOG_INFO, "init: %s", msg + 1);
145 /* Take full control of the log tty, and never close it.
146 * It's mine, all mine! Muhahahaha! */
151 log_fd = device_open(log_console, O_WRONLY | O_NONBLOCK | O_NOCTTY);
153 bb_error_msg("can't log to %s", log_console);
156 close_on_exec_on(log_fd);
160 if (device & L_LOG) {
161 full_write(log_fd, msg, l);
163 return; /* don't print dup messages */
167 if (device & L_CONSOLE) {
168 /* Send console messages to console so people will see them. */
169 full_write(2, msg, l);
173 /* From <linux/serial.h> */
174 struct serial_struct {
183 unsigned short close_delay;
185 char reserved_char[1];
187 unsigned short closing_wait; /* time to wait before closing */
188 unsigned short closing_wait2; /* no longer used... */
189 unsigned char *iomem_base;
190 unsigned short iomem_reg_shift;
191 unsigned int port_high;
192 unsigned long iomap_base; /* cookie passed into ioremap */
194 /* Paranoia (imagine 64bit kernel overwriting 32bit userspace stack) */
195 uint32_t bbox_reserved[16];
197 static void console_init(void)
199 struct serial_struct sr;
202 s = getenv("CONSOLE");
203 if (!s) s = getenv("console");
205 int fd = open(s, O_RDWR | O_NONBLOCK | O_NOCTTY);
210 while (fd > 2) close(fd--);
212 messageD(L_LOG, "console='%s'", s);
214 /* Make sure fd 0,1,2 are not closed */
219 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
220 /* Force the TERM setting to vt102 for serial console
221 * if TERM is set to linux (the default) */
222 if (!s || strcmp(s, "linux") == 0)
223 putenv((char*)"TERM=vt102");
224 if (!ENABLE_FEATURE_INIT_SYSLOG)
227 putenv((char*)"TERM=linux");
230 /* Set terminal settings to reasonable defaults */
231 static void set_sane_term(void)
235 tcgetattr(STDIN_FILENO, &tty);
237 /* set control chars */
238 tty.c_cc[VINTR] = 3; /* C-c */
239 tty.c_cc[VQUIT] = 28; /* C-\ */
240 tty.c_cc[VERASE] = 127; /* C-? */
241 tty.c_cc[VKILL] = 21; /* C-u */
242 tty.c_cc[VEOF] = 4; /* C-d */
243 tty.c_cc[VSTART] = 17; /* C-q */
244 tty.c_cc[VSTOP] = 19; /* C-s */
245 tty.c_cc[VSUSP] = 26; /* C-z */
247 /* use line dicipline 0 */
250 /* Make it be sane */
251 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
252 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
255 tty.c_iflag = ICRNL | IXON | IXOFF;
258 tty.c_oflag = OPOST | ONLCR;
262 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
264 tcsetattr(STDIN_FILENO, TCSANOW, &tty);
267 /* Open the new terminal device */
268 static void open_stdio_to_tty(const char* tty_name, int exit_on_failure)
270 /* empty tty_name means "use init's tty", else... */
274 /* fd can be only < 0 or 0: */
275 fd = device_open(tty_name, O_RDWR);
277 message(L_LOG | L_CONSOLE, "Can't open %s: %s",
278 tty_name, strerror(errno));
281 if (ENABLE_DEBUG_INIT)
283 halt_reboot_pwoff(SIGUSR1); /* halt the system */
291 /* Used only by run_actions */
292 static pid_t run(const struct init_action *a)
296 char *s, *tmpCmd, *cmdpath;
297 char *cmd[INIT_BUFFS_SIZE];
298 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
299 sigset_t nmask, omask;
301 /* Block sigchild while forking (why?) */
303 sigaddset(&nmask, SIGCHLD);
304 sigprocmask(SIG_BLOCK, &nmask, &omask);
306 sigprocmask(SIG_SETMASK, &omask, NULL);
309 message(L_LOG | L_CONSOLE, "Can't fork");
315 /* Reset signal handlers that were set by the parent process */
316 signal(SIGUSR1, SIG_DFL);
317 signal(SIGUSR2, SIG_DFL);
318 signal(SIGINT, SIG_DFL);
319 signal(SIGTERM, SIG_DFL);
320 signal(SIGHUP, SIG_DFL);
321 signal(SIGQUIT, SIG_DFL);
322 signal(SIGCONT, SIG_DFL);
323 signal(SIGSTOP, SIG_DFL);
324 signal(SIGTSTP, SIG_DFL);
326 /* Create a new session and make ourself the process
330 /* Open the new terminal device */
331 open_stdio_to_tty(a->terminal, 1 /* - exit if open fails*/);
333 #ifdef BUT_RUN_ACTIONS_ALREADY_DOES_WAITING
334 /* If the init Action requires us to wait, then force the
335 * supplied terminal to be the controlling tty. */
336 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
337 /* Now fork off another process to just hang around */
340 message(L_LOG | L_CONSOLE, "Can't fork");
345 /* Parent - wait till the child is done */
346 signal(SIGINT, SIG_IGN);
347 signal(SIGTSTP, SIG_IGN);
348 signal(SIGQUIT, SIG_IGN);
349 signal(SIGCHLD, SIG_DFL);
352 /* See if stealing the controlling tty back is necessary */
353 if (tcgetpgrp(0) != getpid())
356 /* Use a temporary process to steal the controlling tty. */
359 message(L_LOG | L_CONSOLE, "Can't fork");
364 ioctl(0, TIOCSCTTY, 1);
371 /* Child - fall though to actually execute things */
375 /* See if any special /bin/sh requiring characters are present */
376 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
377 cmd[0] = (char*)DEFAULT_SHELL;
378 cmd[1] = (char*)"-c";
379 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
382 /* Convert command (char*) into cmd (char**, one word per string) */
383 strcpy(buf, a->command);
385 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
386 if (*tmpCmd != '\0') {
397 * Interactive shells want to see a dash in argv[0]. This
398 * typically is handled by login, argv will be setup this
399 * way if a dash appears at the front of the command path
402 if (*cmdpath == '-') {
403 /* skip over the dash */
406 #ifdef WHY_WE_DO_THIS_SHELL_MUST_HANDLE_THIS_ITSELF
407 /* find the last component in the command pathname */
408 s = bb_get_last_path_component_nostrip(cmdpath);
409 /* make a new argv[0] */
410 cmd[0] = malloc(strlen(s) + 2);
411 if (cmd[0] == NULL) {
412 message(L_LOG | L_CONSOLE, bb_msg_memory_exhausted);
416 strcpy(cmd[0] + 1, s);
420 /* _Attempt_ to make stdin a controlling tty. */
421 if (ENABLE_FEATURE_INIT_SCTTY)
422 ioctl(0, TIOCSCTTY, 0 /*only try, don't steal*/);
425 if (a->action & ASKFIRST) {
426 static const char press_enter[] ALIGN1 =
427 #ifdef CUSTOMIZED_BANNER
428 #include CUSTOMIZED_BANNER
430 "\nPlease press Enter to activate this console. ";
433 * Save memory by not exec-ing anything large (like a shell)
434 * before the user wants it. This is critical if swap is not
435 * enabled and the system has low memory. Generally this will
436 * be run on the second virtual console, and the first will
437 * be allowed to start a shell or whatever an init script
440 messageD(L_LOG, "waiting for enter to start '%s'"
441 "(pid %d, tty '%s')\n",
442 cmdpath, getpid(), a->terminal);
443 full_write(1, press_enter, sizeof(press_enter) - 1);
444 while (safe_read(0, &c, 1) == 1 && c != '\n')
448 /* Log the process name and args */
449 message(L_LOG, "starting pid %d, tty '%s': '%s'",
450 getpid(), a->terminal, cmdpath);
452 if (ENABLE_FEATURE_INIT_COREDUMPS) {
454 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
457 limit.rlim_cur = RLIM_INFINITY;
458 limit.rlim_max = RLIM_INFINITY;
459 setrlimit(RLIMIT_CORE, &limit);
463 /* Now run it. The new program will take over this PID,
464 * so nothing further in init.c should be run. */
465 BB_EXECVP(cmdpath, cmd);
467 /* We're still here? Some error happened. */
468 message(L_LOG | L_CONSOLE, "Cannot run '%s': %s",
469 cmdpath, strerror(errno));
473 /* Run all commands of a particular type */
474 static void run_actions(int action)
476 struct init_action *a, *tmp;
478 for (a = init_action_list; a; a = tmp) {
480 if (a->action == action) {
481 // Pointless: run() will error out if open of device fails.
482 ///* a->terminal of "" means "init's console" */
483 //if (a->terminal[0] && access(a->terminal, R_OK | W_OK)) {
484 // //message(L_LOG | L_CONSOLE, "Device %s cannot be opened in RW mode", a->terminal /*, strerror(errno)*/);
485 // delete_init_action(a);
487 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
489 delete_init_action(a);
490 } else if (a->action & ONCE) {
492 delete_init_action(a);
493 } else if (a->action & (RESPAWN | ASKFIRST)) {
494 /* Only run stuff with pid==0. If they have
495 * a pid, that means it is still running */
504 static void init_reboot(unsigned long magic)
507 /* We have to fork here, since the kernel calls do_exit(0) in
508 * linux/kernel/sys.c, which can cause the machine to panic when
509 * the init process is killed.... */
511 if (pid == 0) { /* child */
518 static void kill_all_processes(void)
520 sigset_t block_signals;
522 /* run everything to be run at "shutdown". This is done _prior_
523 * to killing everything, in case people wish to use scripts to
524 * shut things down gracefully... */
525 run_actions(SHUTDOWN);
527 /* first disable all our signals */
528 sigfillset(&block_signals);
529 /*sigemptyset(&block_signals);
530 sigaddset(&block_signals, SIGHUP);
531 sigaddset(&block_signals, SIGQUIT);
532 sigaddset(&block_signals, SIGCHLD);
533 sigaddset(&block_signals, SIGUSR1);
534 sigaddset(&block_signals, SIGUSR2);
535 sigaddset(&block_signals, SIGINT);
536 sigaddset(&block_signals, SIGTERM);
537 sigaddset(&block_signals, SIGCONT);
538 sigaddset(&block_signals, SIGSTOP);
539 sigaddset(&block_signals, SIGTSTP);*/
540 sigprocmask(SIG_BLOCK, &block_signals, NULL);
542 message(L_CONSOLE | L_LOG, "The system is going down NOW!");
544 /* Allow Ctrl-Alt-Del to reboot system. */
545 init_reboot(RB_ENABLE_CAD);
547 /* Send signals to every process _except_ pid 1 */
548 message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "TERM");
553 message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "KILL");
559 static void halt_reboot_pwoff(int sig)
564 kill_all_processes();
568 if (sig == SIGTERM) {
571 } else if (sig == SIGUSR2) {
575 message(L_CONSOLE | L_LOG, "Requesting system %s", m);
576 /* allow time for last message to reach serial console */
582 /* Handler for HUP and QUIT - exec "restart" action,
583 * else (no such action defined) do nothing */
584 static void exec_restart_action(int sig ATTRIBUTE_UNUSED)
586 struct init_action *a, *tmp;
587 sigset_t unblock_signals;
589 for (a = init_action_list; a; a = tmp) {
591 if (a->action & RESTART) {
592 kill_all_processes();
594 /* unblock all signals (blocked in kill_all_processes()) */
595 sigfillset(&unblock_signals);
596 /*sigemptyset(&unblock_signals);
597 sigaddset(&unblock_signals, SIGHUP);
598 sigaddset(&unblock_signals, SIGQUIT);
599 sigaddset(&unblock_signals, SIGCHLD);
600 sigaddset(&unblock_signals, SIGUSR1);
601 sigaddset(&unblock_signals, SIGUSR2);
602 sigaddset(&unblock_signals, SIGINT);
603 sigaddset(&unblock_signals, SIGTERM);
604 sigaddset(&unblock_signals, SIGCONT);
605 sigaddset(&unblock_signals, SIGSTOP);
606 sigaddset(&unblock_signals, SIGTSTP);*/
607 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
609 /* Open the new terminal device */
610 open_stdio_to_tty(a->terminal, 0 /* - halt if open fails */);
612 messageD(L_CONSOLE | L_LOG, "Trying to re-exec %s", a->command);
613 BB_EXECLP(a->command, a->command, NULL);
615 message(L_CONSOLE | L_LOG, "Cannot run '%s': %s",
616 a->command, strerror(errno));
618 init_reboot(RB_HALT_SYSTEM);
624 static void ctrlaltdel_signal(int sig ATTRIBUTE_UNUSED)
626 run_actions(CTRLALTDEL);
629 /* The SIGSTOP & SIGTSTP handler */
630 static void stop_handler(int sig ATTRIBUTE_UNUSED)
632 int saved_errno = errno;
641 /* The SIGCONT handler */
642 static void cont_handler(int sig ATTRIBUTE_UNUSED)
647 static void new_init_action(uint8_t action, const char *command, const char *cons)
649 struct init_action *new_action, *a, *last;
651 if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST))
654 /* Append to the end of the list */
655 for (a = last = init_action_list; a; a = a->next) {
656 /* don't enter action if it's already in the list,
657 * but do overwrite existing actions */
658 if ((strcmp(a->command, command) == 0)
659 && (strcmp(a->terminal, cons) == 0)
667 new_action = xzalloc(sizeof(struct init_action));
669 last->next = new_action;
671 init_action_list = new_action;
673 strcpy(new_action->command, command);
674 new_action->action = action;
675 strcpy(new_action->terminal, cons);
676 messageD(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n",
677 new_action->command, new_action->action, new_action->terminal);
680 static void delete_init_action(struct init_action *action)
682 struct init_action *a, *b = NULL;
684 for (a = init_action_list; a; b = a, a = a->next) {
687 init_action_list = a->next;
697 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
698 * then parse_inittab() simply adds in some default
699 * actions(i.e., runs INIT_SCRIPT and then starts a pair
700 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
701 * _is_ defined, but /etc/inittab is missing, this
702 * results in the same set of default behaviors.
704 static void parse_inittab(void)
707 char buf[INIT_BUFFS_SIZE];
709 if (ENABLE_FEATURE_USE_INITTAB)
710 file = fopen(INITTAB, "r");
714 /* No inittab file -- set up some default behavior */
716 /* Reboot on Ctrl-Alt-Del */
717 new_init_action(CTRLALTDEL, "reboot", "");
718 /* Umount all filesystems on halt/reboot */
719 new_init_action(SHUTDOWN, "umount -a -r", "");
720 /* Swapoff on halt/reboot */
721 if (ENABLE_SWAPONOFF)
722 new_init_action(SHUTDOWN, "swapoff -a", "");
723 /* Prepare to restart init when a HUP is received */
724 new_init_action(RESTART, "init", "");
725 /* Askfirst shell on tty1-4 */
726 new_init_action(ASKFIRST, bb_default_login_shell, "");
727 new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
728 new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
729 new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
731 new_init_action(SYSINIT, INIT_SCRIPT, "");
736 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
737 static const char actions[] =
738 STR_SYSINIT "sysinit\0"
739 STR_RESPAWN "respawn\0"
740 STR_ASKFIRST "askfirst\0"
743 STR_CTRLALTDEL "ctrlaltdel\0"
744 STR_SHUTDOWN "shutdown\0"
745 STR_RESTART "restart\0"
747 char tmpConsole[CONSOLE_NAME_SIZE];
748 char *id, *runlev, *action, *command;
751 /* Skip leading spaces */
752 id = skip_whitespace(buf);
753 /* Skip the line if it's a comment */
754 if (*id == '#' || *id == '\n')
756 /* Trim the trailing '\n' */
757 *strchrnul(id, '\n') = '\0';
759 /* Line is: "id:runlevel_ignored:action:command" */
760 runlev = strchr(id, ':');
761 if (runlev == NULL /*|| runlev[1] == '\0' - not needed */)
763 action = strchr(runlev + 1, ':');
764 if (action == NULL /*|| action[1] == '\0' - not needed */)
766 command = strchr(action + 1, ':');
767 if (command == NULL || command[1] == '\0')
770 *command = '\0'; /* action => ":action\0" now */
771 for (a = actions; a[0]; a += strlen(a) + 1) {
772 if (strcmp(a + 1, action + 1) == 0) {
775 if (strncmp(id, "/dev/", 5) == 0)
777 strcpy(tmpConsole, "/dev/");
778 safe_strncpy(tmpConsole + 5, id,
779 sizeof(tmpConsole) - 5);
782 new_init_action((uint8_t)a[0], command + 1, id);
787 /* Choke on an unknown action */
789 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", id);
795 static void reload_signal(int sig ATTRIBUTE_UNUSED)
797 struct init_action *a, *tmp;
799 message(L_LOG, "reloading /etc/inittab");
801 /* disable old entrys */
802 for (a = init_action_list; a; a = a->next) {
808 if (ENABLE_FEATURE_KILL_REMOVED) {
809 /* Be nice and send SIGTERM first */
810 for (a = init_action_list; a; a = a->next) {
812 if ((a->action & ONCE) && pid != 0) {
816 #if CONFIG_FEATURE_KILL_DELAY
817 if (fork() == 0) { /* child */
818 sleep(CONFIG_FEATURE_KILL_DELAY);
819 for (a = init_action_list; a; a = a->next) {
821 if ((a->action & ONCE) && pid != 0) {
830 /* remove unused entrys */
831 for (a = init_action_list; a; a = tmp) {
833 if ((a->action & (ONCE | SYSINIT | WAIT)) && a->pid == 0) {
834 delete_init_action(a);
837 run_actions(RESPAWN);
840 int init_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
841 int init_main(int argc, char **argv)
843 struct init_action *a;
846 die_sleep = 30 * 24*60*60; /* if xmalloc will ever die... */
848 if (argc > 1 && !strcmp(argv[1], "-q")) {
849 return kill(1, SIGHUP);
852 if (!ENABLE_DEBUG_INIT) {
853 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
855 && (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc"))
859 /* Set up sig handlers -- be sure to
860 * clear all of these in run() */
861 signal(SIGHUP, exec_restart_action);
862 signal(SIGQUIT, exec_restart_action);
863 signal(SIGUSR1, halt_reboot_pwoff); /* halt */
864 signal(SIGUSR2, halt_reboot_pwoff); /* poweroff */
865 signal(SIGTERM, halt_reboot_pwoff); /* reboot */
866 signal(SIGINT, ctrlaltdel_signal);
867 signal(SIGCONT, cont_handler);
868 signal(SIGSTOP, stop_handler);
869 signal(SIGTSTP, stop_handler);
871 /* Turn off rebooting via CTL-ALT-DEL -- we get a
872 * SIGINT on CAD so we can shut things down gracefully... */
873 init_reboot(RB_DISABLE_CAD);
876 /* Figure out where the default console should be */
882 const char *const *e;
883 /* Make sure environs is set to something sane */
884 for (e = environment; *e; e++)
888 if (argc > 1) setenv("RUNLEVEL", argv[1], 1);
891 message(MAYBE_CONSOLE | L_LOG, "init started: %s", bb_banner);
893 /* Make sure there is enough memory to do something useful. */
894 if (ENABLE_SWAPONOFF) {
897 if (!sysinfo(&info) &&
898 (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024)
900 message(L_CONSOLE, "Low memory, forcing swapon");
901 /* swapon -a requires /proc typically */
902 new_init_action(SYSINIT, "mount -t proc proc /proc", "");
903 /* Try to turn on swap */
904 new_init_action(SYSINIT, "swapon -a", "");
905 run_actions(SYSINIT); /* wait and removing */
909 /* Check if we are supposed to be in single user mode */
911 && (!strcmp(argv[1], "single") || !strcmp(argv[1], "-s") || LONE_CHAR(argv[1], '1'))
913 /* Start a shell on console */
914 new_init_action(RESPAWN, bb_default_login_shell, "");
916 /* Not in single user mode -- see what inittab says */
918 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
919 * then parse_inittab() simply adds in some default
920 * actions(i.e., runs INIT_SCRIPT and then starts a pair
921 * of "askfirst" shells */
926 if (getenv("SELINUX_INIT") == NULL) {
929 putenv((char*)"SELINUX_INIT=YES");
930 if (selinux_init_load_policy(&enforce) == 0) {
931 BB_EXECVP(argv[0], argv);
932 } else if (enforce > 0) {
933 /* SELinux in enforcing mode but load_policy failed */
934 message(L_CONSOLE, "Cannot load SELinux Policy. "
935 "Machine is in enforcing mode. Halting now.");
939 #endif /* CONFIG_SELINUX */
941 /* Make the command line just say "init" - thats all, nothing else */
942 strncpy(argv[0], "init", strlen(argv[0]));
943 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
945 memset(*argv, 0, strlen(*argv));
947 /* Now run everything that needs to be run */
949 /* First run the sysinit command */
950 run_actions(SYSINIT);
952 /* Next run anything that wants to block */
955 /* Next run anything to be run only once */
958 /* Redefine SIGHUP to reread /etc/inittab */
959 if (ENABLE_FEATURE_USE_INITTAB)
960 signal(SIGHUP, reload_signal);
962 signal(SIGHUP, SIG_IGN);
964 /* Now run the looping stuff for the rest of forever */
966 /* run the respawn stuff */
967 run_actions(RESPAWN);
969 /* run the askfirst stuff */
970 run_actions(ASKFIRST);
972 /* Don't consume all CPU time -- sleep a bit */
975 /* Wait for any child process to exit */
978 /* Find out who died and clean up their corpse */
979 for (a = init_action_list; a; a = a->next) {
980 if (a->pid == wpid) {
981 /* Set the pid to 0 so that the process gets
982 * restarted by run_actions() */
984 message(L_LOG, "process '%s' (pid %d) exited. "
985 "Scheduling it for restart.",
989 /* see if anyone else is waiting to be reaped */
990 wpid = wait_any_nohang(NULL);