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.
15 #include <sys/ioctl.h>
17 #include <sys/reboot.h>
20 # include <sys/syslog.h>
23 #define INIT_BUFFS_SIZE 256
24 #define CONSOLE_NAME_SIZE 32
25 #define MAXENV 16 /* Number of env. vars */
28 #define _PATH_STDPATH "/usr/bin:/bin:/usr/sbin:/sbin"
31 #if ENABLE_FEATURE_INIT_COREDUMPS
33 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
34 * before processes are spawned to set core file size as unlimited.
35 * This is for debugging only. Don't use this is production, unless
36 * you want core dumps lying about....
38 #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
39 #include <sys/resource.h>
42 #define INITTAB "/etc/inittab" /* inittab file location */
44 #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
47 /* Allowed init action types */
50 #define ASKFIRST 0x004
53 #define CTRLALTDEL 0x020
54 #define SHUTDOWN 0x040
57 /* A mapping between "inittab" action name strings and action type codes. */
58 struct init_action_type {
63 static const struct init_action_type actions[] = {
66 {"askfirst", ASKFIRST},
69 {"ctrlaltdel", CTRLALTDEL},
70 {"shutdown", SHUTDOWN},
75 /* Set up a linked list of init_actions, to be read from inittab */
77 struct init_action *next;
80 char command[INIT_BUFFS_SIZE];
81 char terminal[CONSOLE_NAME_SIZE];
84 /* Static variables */
85 static struct init_action *init_action_list = NULL;
88 static const char *log_console = VC_5;
90 #if !ENABLE_DEBUG_INIT
91 static sig_atomic_t got_cont = 0;
98 #if ENABLE_FEATURE_EXTRA_QUIET
101 MAYBE_CONSOLE = L_CONSOLE,
104 #ifndef RB_HALT_SYSTEM
105 RB_HALT_SYSTEM = 0xcdef0123, /* FIXME: this overflows enum */
106 RB_ENABLE_CAD = 0x89abcdef,
108 RB_POWER_OFF = 0x4321fedc,
109 RB_AUTOBOOT = 0x01234567,
113 static const char * const environment[] = {
115 "PATH=" _PATH_STDPATH,
121 /* Function prototypes */
122 static void delete_init_action(struct init_action *a);
123 static int waitfor(const struct init_action *a, pid_t pid);
124 #if !ENABLE_DEBUG_INIT
125 static void shutdown_signal(int sig);
128 #if !ENABLE_DEBUG_INIT
129 static void loop_forever(void)
136 /* Print a message to the specified device.
137 * Device may be bitwise-or'd from L_LOG | L_CONSOLE */
138 #if ENABLE_DEBUG_INIT
139 #define messageD message
141 #define messageD(...) do {} while (0)
143 static void message(int device, const char *fmt, ...)
144 __attribute__ ((format(printf, 2, 3)));
145 static void message(int device, const char *fmt, ...)
148 static int log_fd = -1;
156 va_start(arguments, fmt);
157 vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments);
159 msg[sizeof(msg) - 2] = '\0';
163 /* Log the message to syslogd */
164 if (device & L_LOG) {
166 openlog(applet_name, 0, LOG_DAEMON);
167 syslog(LOG_INFO, "init: %s", msg + 1);
175 /* Take full control of the log tty, and never close it.
176 * It's mine, all mine! Muhahahaha! */
181 log_fd = device_open(log_console, O_WRONLY | O_NONBLOCK | O_NOCTTY);
183 bb_error_msg("can't log to %s", log_console);
186 fcntl(log_fd, F_SETFD, FD_CLOEXEC);
190 if (device & L_LOG) {
191 full_write(log_fd, msg, l);
193 return; /* don't print dup messages */
197 if (device & L_CONSOLE) {
198 /* Send console messages to console so people will see them. */
199 full_write(2, msg, l);
203 /* Set terminal settings to reasonable defaults */
204 static void set_term(void)
208 tcgetattr(STDIN_FILENO, &tty);
210 /* set control chars */
211 tty.c_cc[VINTR] = 3; /* C-c */
212 tty.c_cc[VQUIT] = 28; /* C-\ */
213 tty.c_cc[VERASE] = 127; /* C-? */
214 tty.c_cc[VKILL] = 21; /* C-u */
215 tty.c_cc[VEOF] = 4; /* C-d */
216 tty.c_cc[VSTART] = 17; /* C-q */
217 tty.c_cc[VSTOP] = 19; /* C-s */
218 tty.c_cc[VSUSP] = 26; /* C-z */
220 /* use line dicipline 0 */
223 /* Make it be sane */
224 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
225 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
228 tty.c_iflag = ICRNL | IXON | IXOFF;
231 tty.c_oflag = OPOST | ONLCR;
235 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
237 tcsetattr(STDIN_FILENO, TCSANOW, &tty);
240 /* From <linux/serial.h> */
241 struct serial_struct {
250 unsigned short close_delay;
252 char reserved_char[1];
254 unsigned short closing_wait; /* time to wait before closing */
255 unsigned short closing_wait2; /* no longer used... */
256 unsigned char *iomem_base;
257 unsigned short iomem_reg_shift;
258 unsigned int port_high;
259 unsigned long iomap_base; /* cookie passed into ioremap */
261 /* Paranoia (imagine 64bit kernel overwriting 32bit userspace stack) */
262 uint32_t bbox_reserved[16];
264 static void console_init(void)
266 struct serial_struct sr;
269 s = getenv("CONSOLE");
270 if (!s) s = getenv("console");
272 int fd = open(s, O_RDWR | O_NONBLOCK | O_NOCTTY);
277 while (fd > 2) close(fd--);
279 messageD(L_LOG, "console='%s'", s);
283 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
284 /* Force the TERM setting to vt102 for serial console --
285 * if TERM is set to linux (the default) */
286 if (!s || strcmp(s, "linux") == 0)
287 putenv((char*)"TERM=vt102");
292 putenv((char*)"TERM=linux");
295 static void fixup_argv(int argc, char **argv, const char *new_argv0)
299 /* Fix up argv[0] to be certain we claim to be init */
300 len = strlen(argv[0]);
301 strncpy(argv[0], new_argv0, len);
303 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
306 memset(argv[len], 0, strlen(argv[len]));
311 /* Open the new terminal device */
312 static void open_stdio_to_tty(const char* tty_name, int fail)
314 /* empty tty_name means "use init's tty", else... */
317 if ((device_open(tty_name, O_RDWR)) < 0) {
318 dup2(1, 0); /* restore fd #0 - avoid nasty surprises */
319 message(L_LOG | L_CONSOLE, "can't open %s: %s",
320 tty_name, strerror(errno));
323 #if !ENABLE_DEBUG_INIT
324 shutdown_signal(SIGUSR1);
337 static pid_t run(const struct init_action *a)
341 char *s, *tmpCmd, *cmdpath;
342 char *cmd[INIT_BUFFS_SIZE];
343 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
344 sigset_t nmask, omask;
345 static const char press_enter[] =
346 #ifdef CUSTOMIZED_BANNER
347 #include CUSTOMIZED_BANNER
349 "\nPlease press Enter to activate this console. ";
351 /* Block sigchild while forking. */
353 sigaddset(&nmask, SIGCHLD);
354 sigprocmask(SIG_BLOCK, &nmask, &omask);
356 if ((pid = fork()) == 0) {
358 sigprocmask(SIG_SETMASK, &omask, NULL);
360 /* Reset signal handlers that were set by the parent process */
361 signal(SIGUSR1, SIG_DFL);
362 signal(SIGUSR2, SIG_DFL);
363 signal(SIGINT, SIG_DFL);
364 signal(SIGTERM, SIG_DFL);
365 signal(SIGHUP, SIG_DFL);
366 signal(SIGQUIT, SIG_DFL);
367 signal(SIGCONT, SIG_DFL);
368 signal(SIGSTOP, SIG_DFL);
369 signal(SIGTSTP, SIG_DFL);
371 /* Create a new session and make ourself the process
375 /* Open the new terminal device */
376 open_stdio_to_tty(a->terminal, 1);
378 /* If the init Action requires us to wait, then force the
379 * supplied terminal to be the controlling tty. */
380 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
382 /* Now fork off another process to just hang around */
383 if ((pid = fork()) < 0) {
384 message(L_LOG | L_CONSOLE, "can't fork");
390 /* We are the parent -- wait till the child is done */
391 signal(SIGINT, SIG_IGN);
392 signal(SIGTSTP, SIG_IGN);
393 signal(SIGQUIT, SIG_IGN);
394 signal(SIGCHLD, SIG_DFL);
397 /* See if stealing the controlling tty back is necessary */
398 if (tcgetpgrp(0) != getpid())
401 /* Use a temporary process to steal the controlling tty. */
402 if ((pid = fork()) < 0) {
403 message(L_LOG | L_CONSOLE, "can't fork");
408 ioctl(0, TIOCSCTTY, 1);
415 /* Now fall though to actually execute things */
418 /* See if any special /bin/sh requiring characters are present */
419 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
420 cmd[0] = (char *)DEFAULT_SHELL;
421 cmd[1] = (char*)"-c";
422 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
425 /* Convert command (char*) into cmd (char**, one word per string) */
426 strcpy(buf, a->command);
428 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
429 if (*tmpCmd != '\0') {
440 * Interactive shells want to see a dash in argv[0]. This
441 * typically is handled by login, argv will be setup this
442 * way if a dash appears at the front of the command path
445 if (*cmdpath == '-') {
446 /* skip over the dash */
449 /* find the last component in the command pathname */
450 s = bb_get_last_path_component(cmdpath);
452 /* make a new argv[0] */
453 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
454 message(L_LOG | L_CONSOLE, bb_msg_memory_exhausted);
458 strcpy(cmd[0] + 1, s);
460 #if ENABLE_FEATURE_INIT_SCTTY
461 /* Establish this process as session leader and
462 * (attempt) to make the tty (if any) a controlling tty.
465 ioctl(0, TIOCSCTTY, 0 /*don't steal it*/);
469 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
470 if (a->action & ASKFIRST) {
473 * Save memory by not exec-ing anything large (like a shell)
474 * before the user wants it. This is critical if swap is not
475 * enabled and the system has low memory. Generally this will
476 * be run on the second virtual console, and the first will
477 * be allowed to start a shell or whatever an init script
480 messageD(L_LOG, "Waiting for enter to start '%s'"
481 "(pid %d, tty '%s')\n",
482 cmdpath, getpid(), a->terminal);
483 full_write(1, press_enter, sizeof(press_enter) - 1);
484 while (read(0, &c, 1) == 1 && c != '\n')
489 /* Log the process name and args */
490 message(L_LOG, "starting pid %d, tty '%s': '%s'",
491 getpid(), a->terminal, cmdpath);
493 #if ENABLE_FEATURE_INIT_COREDUMPS
496 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
499 limit.rlim_cur = RLIM_INFINITY;
500 limit.rlim_max = RLIM_INFINITY;
501 setrlimit(RLIMIT_CORE, &limit);
506 /* Now run it. The new program will take over this PID,
507 * so nothing further in init.c should be run. */
508 BB_EXECVP(cmdpath, cmd);
510 /* We're still here? Some error happened. */
511 message(L_LOG | L_CONSOLE, "Cannot run '%s': %s",
512 cmdpath, strerror(errno));
515 sigprocmask(SIG_SETMASK, &omask, NULL);
519 static int waitfor(const struct init_action *a, pid_t pid)
524 runpid = (NULL == a)? pid : run(a);
526 wpid = waitpid(runpid, &status, 0);
529 if (wpid == -1 && errno == ECHILD) {
530 /* we missed its termination */
533 /* FIXME other errors should maybe trigger an error, but allow
534 * the program to continue */
539 /* Run all commands of a particular type */
540 static void run_actions(int action)
542 struct init_action *a, *tmp;
544 for (a = init_action_list; a; a = tmp) {
546 if (a->action == action) {
547 /* a->terminal of "" means "init's console" */
548 if (a->terminal[0] && access(a->terminal, R_OK | W_OK)) {
549 delete_init_action(a);
550 } else if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
552 delete_init_action(a);
553 } else if (a->action & ONCE) {
555 delete_init_action(a);
556 } else if (a->action & (RESPAWN | ASKFIRST)) {
557 /* Only run stuff with pid==0. If they have
558 * a pid, that means it is still running */
567 #if !ENABLE_DEBUG_INIT
568 static void init_reboot(unsigned long magic)
571 /* We have to fork here, since the kernel calls do_exit(0) in
572 * linux/kernel/sys.c, which can cause the machine to panic when
573 * the init process is killed.... */
575 if (pid == 0) { /* child */
579 waitpid(pid, NULL, 0);
582 static void shutdown_system(void)
584 sigset_t block_signals;
586 /* run everything to be run at "shutdown". This is done _prior_
587 * to killing everything, in case people wish to use scripts to
588 * shut things down gracefully... */
589 run_actions(SHUTDOWN);
591 /* first disable all our signals */
592 sigemptyset(&block_signals);
593 sigaddset(&block_signals, SIGHUP);
594 sigaddset(&block_signals, SIGQUIT);
595 sigaddset(&block_signals, SIGCHLD);
596 sigaddset(&block_signals, SIGUSR1);
597 sigaddset(&block_signals, SIGUSR2);
598 sigaddset(&block_signals, SIGINT);
599 sigaddset(&block_signals, SIGTERM);
600 sigaddset(&block_signals, SIGCONT);
601 sigaddset(&block_signals, SIGSTOP);
602 sigaddset(&block_signals, SIGTSTP);
603 sigprocmask(SIG_BLOCK, &block_signals, NULL);
605 message(L_CONSOLE | L_LOG, "The system is going down NOW!");
607 /* Allow Ctrl-Alt-Del to reboot system. */
608 init_reboot(RB_ENABLE_CAD);
610 /* Send signals to every process _except_ pid 1 */
611 message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "TERM");
616 message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "KILL");
622 static void exec_signal(int sig ATTRIBUTE_UNUSED)
624 struct init_action *a, *tmp;
625 sigset_t unblock_signals;
627 for (a = init_action_list; a; a = tmp) {
629 if (a->action & RESTART) {
632 /* unblock all signals, blocked in shutdown_system() */
633 sigemptyset(&unblock_signals);
634 sigaddset(&unblock_signals, SIGHUP);
635 sigaddset(&unblock_signals, SIGQUIT);
636 sigaddset(&unblock_signals, SIGCHLD);
637 sigaddset(&unblock_signals, SIGUSR1);
638 sigaddset(&unblock_signals, SIGUSR2);
639 sigaddset(&unblock_signals, SIGINT);
640 sigaddset(&unblock_signals, SIGTERM);
641 sigaddset(&unblock_signals, SIGCONT);
642 sigaddset(&unblock_signals, SIGSTOP);
643 sigaddset(&unblock_signals, SIGTSTP);
644 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
646 /* Open the new terminal device */
647 open_stdio_to_tty(a->terminal, 0);
649 messageD(L_CONSOLE | L_LOG, "Trying to re-exec %s", a->command);
650 BB_EXECLP(a->command, a->command, NULL);
652 message(L_CONSOLE | L_LOG, "Cannot run '%s': %s",
653 a->command, strerror(errno));
655 init_reboot(RB_HALT_SYSTEM);
661 static void shutdown_signal(int sig)
670 if (sig == SIGTERM) {
673 } else if (sig == SIGUSR2) {
677 message(L_CONSOLE | L_LOG, "Requesting system %s", m);
678 /* allow time for last message to reach serial console */
684 static void ctrlaltdel_signal(int sig ATTRIBUTE_UNUSED)
686 run_actions(CTRLALTDEL);
689 /* The SIGSTOP & SIGTSTP handler */
690 static void stop_handler(int sig ATTRIBUTE_UNUSED)
692 int saved_errno = errno;
701 /* The SIGCONT handler */
702 static void cont_handler(int sig ATTRIBUTE_UNUSED)
707 #endif /* !ENABLE_DEBUG_INIT */
709 static void new_init_action(int action, const char *command, const char *cons)
711 struct init_action *new_action, *a, *last;
713 if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST))
716 /* Append to the end of the list */
717 for (a = last = init_action_list; a; a = a->next) {
718 /* don't enter action if it's already in the list,
719 * but do overwrite existing actions */
720 if ((strcmp(a->command, command) == 0)
721 && (strcmp(a->terminal, cons) == 0)
729 new_action = xzalloc(sizeof(struct init_action));
731 last->next = new_action;
733 init_action_list = new_action;
735 strcpy(new_action->command, command);
736 new_action->action = action;
737 strcpy(new_action->terminal, cons);
738 messageD(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n",
739 new_action->command, new_action->action, new_action->terminal);
742 static void delete_init_action(struct init_action *action)
744 struct init_action *a, *b = NULL;
746 for (a = init_action_list; a; b = a, a = a->next) {
749 init_action_list = a->next;
759 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
760 * then parse_inittab() simply adds in some default
761 * actions(i.e., runs INIT_SCRIPT and then starts a pair
762 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
763 * _is_ defined, but /etc/inittab is missing, this
764 * results in the same set of default behaviors.
766 static void parse_inittab(void)
768 #if ENABLE_FEATURE_USE_INITTAB
770 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
771 char tmpConsole[CONSOLE_NAME_SIZE];
772 char *id, *runlev, *action, *command, *eol;
773 const struct init_action_type *a = actions;
775 file = fopen(INITTAB, "r");
777 /* No inittab file -- set up some default behavior */
779 /* Reboot on Ctrl-Alt-Del */
780 new_init_action(CTRLALTDEL, "reboot", "");
781 /* Umount all filesystems on halt/reboot */
782 new_init_action(SHUTDOWN, "umount -a -r", "");
783 /* Swapoff on halt/reboot */
784 if (ENABLE_SWAPONOFF) new_init_action(SHUTDOWN, "swapoff -a", "");
785 /* Prepare to restart init when a HUP is received */
786 new_init_action(RESTART, "init", "");
787 /* Askfirst shell on tty1-4 */
788 new_init_action(ASKFIRST, bb_default_login_shell, "");
789 new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
790 new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
791 new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
793 new_init_action(SYSINIT, INIT_SCRIPT, "");
796 #if ENABLE_FEATURE_USE_INITTAB
799 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
800 /* Skip leading spaces */
801 for (id = buf; *id == ' ' || *id == '\t'; id++);
803 /* Skip the line if it's a comment */
804 if (*id == '#' || *id == '\n')
807 /* Trim the trailing \n */
809 eol = strrchr(id, '\n');
813 /* Keep a copy around for posterity's sake (and error msgs) */
814 strcpy(lineAsRead, buf);
816 /* Separate the ID field from the runlevels */
817 runlev = strchr(id, ':');
818 if (runlev == NULL || *(runlev + 1) == '\0') {
819 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
826 /* Separate the runlevels from the action */
827 action = strchr(runlev, ':');
828 if (action == NULL || *(action + 1) == '\0') {
829 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
836 /* Separate the action from the command */
837 command = strchr(action, ':');
838 if (command == NULL || *(command + 1) == '\0') {
839 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
846 /* Ok, now process it */
847 for (a = actions; a->name != 0; a++) {
848 if (strcmp(a->name, action) == 0) {
850 if(strncmp(id, "/dev/", 5) == 0)
852 strcpy(tmpConsole, "/dev/");
853 safe_strncpy(tmpConsole + 5, id,
854 sizeof(tmpConsole) - 5);
857 new_init_action(a->action, command, id);
862 /* Choke on an unknown action */
863 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
867 #endif /* FEATURE_USE_INITTAB */
870 #if ENABLE_FEATURE_USE_INITTAB
871 static void reload_signal(int sig ATTRIBUTE_UNUSED)
873 struct init_action *a, *tmp;
875 message(L_LOG, "reloading /etc/inittab");
877 /* disable old entrys */
878 for (a = init_action_list; a; a = a->next ) {
884 /* remove unused entrys */
885 for (a = init_action_list; a; a = tmp) {
887 if (a->action & (ONCE | SYSINIT | WAIT ) &&
889 delete_init_action(a);
892 run_actions(RESPAWN);
894 #endif /* FEATURE_USE_INITTAB */
896 int init_main(int argc, char **argv);
897 int init_main(int argc, char **argv)
899 struct init_action *a;
902 die_sleep = 30 * 24*60*60; /* if xmalloc will ever die... */
904 if (argc > 1 && !strcmp(argv[1], "-q")) {
905 return kill(1, SIGHUP);
907 #if !ENABLE_DEBUG_INIT
908 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
910 && (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc"))
914 /* Set up sig handlers -- be sure to
915 * clear all of these in run() */
916 signal(SIGHUP, exec_signal);
917 signal(SIGQUIT, exec_signal);
918 signal(SIGUSR1, shutdown_signal);
919 signal(SIGUSR2, shutdown_signal);
920 signal(SIGINT, ctrlaltdel_signal);
921 signal(SIGTERM, shutdown_signal);
922 signal(SIGCONT, cont_handler);
923 signal(SIGSTOP, stop_handler);
924 signal(SIGTSTP, stop_handler);
926 /* Turn off rebooting via CTL-ALT-DEL -- we get a
927 * SIGINT on CAD so we can shut things down gracefully... */
928 init_reboot(RB_DISABLE_CAD);
931 /* Figure out where the default console should be */
937 const char * const *e;
938 /* Make sure environs is set to something sane */
939 for (e = environment; *e; e++)
943 if (argc > 1) setenv("RUNLEVEL", argv[1], 1);
946 message(MAYBE_CONSOLE | L_LOG, "init started: %s", bb_msg_full_version);
948 /* Make sure there is enough memory to do something useful. */
949 if (ENABLE_SWAPONOFF) {
952 if (!sysinfo(&info) &&
953 (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024)
955 message(L_CONSOLE, "Low memory, forcing swapon");
956 /* swapon -a requires /proc typically */
957 new_init_action(SYSINIT, "mount -t proc proc /proc", "");
958 /* Try to turn on swap */
959 new_init_action(SYSINIT, "swapon -a", "");
960 run_actions(SYSINIT); /* wait and removing */
964 /* Check if we are supposed to be in single user mode */
966 && (!strcmp(argv[1], "single") || !strcmp(argv[1], "-s") || LONE_CHAR(argv[1], '1'))
968 /* Start a shell on console */
969 new_init_action(RESPAWN, bb_default_login_shell, "");
971 /* Not in single user mode -- see what inittab says */
973 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
974 * then parse_inittab() simply adds in some default
975 * actions(i.e., runs INIT_SCRIPT and then starts a pair
976 * of "askfirst" shells */
981 if (getenv("SELINUX_INIT") == NULL) {
984 putenv("SELINUX_INIT=YES");
985 if (selinux_init_load_policy(&enforce) == 0) {
986 BB_EXECVP(argv[0], argv);
987 } else if (enforce > 0) {
988 /* SELinux in enforcing mode but load_policy failed */
989 /* At this point, we probably can't open /dev/console, so log() won't work */
990 message(L_CONSOLE, "Cannot load SELinux Policy. "
991 "Machine is in enforcing mode. Halting now.");
995 #endif /* CONFIG_SELINUX */
997 /* Make the command line just say "init" -- thats all, nothing else */
998 fixup_argv(argc, argv, "init");
1000 /* Now run everything that needs to be run */
1002 /* First run the sysinit command */
1003 run_actions(SYSINIT);
1005 /* Next run anything that wants to block */
1008 /* Next run anything to be run only once */
1011 #if ENABLE_FEATURE_USE_INITTAB
1012 /* Redefine SIGHUP to reread /etc/inittab */
1013 signal(SIGHUP, reload_signal);
1015 signal(SIGHUP, SIG_IGN);
1016 #endif /* FEATURE_USE_INITTAB */
1018 /* Now run the looping stuff for the rest of forever */
1020 /* run the respawn stuff */
1021 run_actions(RESPAWN);
1023 /* run the askfirst stuff */
1024 run_actions(ASKFIRST);
1026 /* Don't consume all CPU time -- sleep a bit */
1029 /* Wait for a child process to exit */
1032 /* Find out who died and clean up their corpse */
1033 for (a = init_action_list; a; a = a->next) {
1034 if (a->pid == wpid) {
1035 /* Set the pid to 0 so that the process gets
1036 * restarted by run_actions() */
1038 message(L_LOG, "process '%s' (pid %d) exited. "
1039 "Scheduling it for restart.",
1043 /* see if anyone else is waiting to be reaped */
1044 wpid = waitpid(-1, NULL, WNOHANG);