[821] | 1 | /* vi: set sw=4 ts=4: */
|
---|
| 2 | /*
|
---|
| 3 | * Mini init implementation for busybox
|
---|
| 4 | *
|
---|
| 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.
|
---|
| 8 | *
|
---|
[2725] | 9 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
---|
[821] | 10 | */
|
---|
| 11 |
|
---|
[2725] | 12 | //config:config INIT
|
---|
| 13 | //config: bool "init"
|
---|
| 14 | //config: default y
|
---|
| 15 | //config: select FEATURE_SYSLOG
|
---|
| 16 | //config: help
|
---|
| 17 | //config: init is the first program run when the system boots.
|
---|
| 18 | //config:
|
---|
[3621] | 19 | //config:config LINUXRC
|
---|
| 20 | //config: bool "Support running init from within an initrd (not initramfs)"
|
---|
| 21 | //config: default y
|
---|
| 22 | //config: select FEATURE_SYSLOG
|
---|
| 23 | //config: help
|
---|
| 24 | //config: Legacy support for running init under the old-style initrd. Allows
|
---|
| 25 | //config: the name linuxrc to act as init, and it doesn't assume init is PID 1.
|
---|
| 26 | //config:
|
---|
| 27 | //config: This does not apply to initramfs, which runs /init as PID 1 and
|
---|
| 28 | //config: requires no special support.
|
---|
| 29 | //config:
|
---|
[2725] | 30 | //config:config FEATURE_USE_INITTAB
|
---|
| 31 | //config: bool "Support reading an inittab file"
|
---|
| 32 | //config: default y
|
---|
[3621] | 33 | //config: depends on INIT || LINUXRC
|
---|
[2725] | 34 | //config: help
|
---|
| 35 | //config: Allow init to read an inittab file when the system boot.
|
---|
| 36 | //config:
|
---|
| 37 | //config:config FEATURE_KILL_REMOVED
|
---|
| 38 | //config: bool "Support killing processes that have been removed from inittab"
|
---|
| 39 | //config: default n
|
---|
| 40 | //config: depends on FEATURE_USE_INITTAB
|
---|
| 41 | //config: help
|
---|
| 42 | //config: When respawn entries are removed from inittab and a SIGHUP is
|
---|
| 43 | //config: sent to init, this option will make init kill the processes
|
---|
| 44 | //config: that have been removed.
|
---|
| 45 | //config:
|
---|
| 46 | //config:config FEATURE_KILL_DELAY
|
---|
| 47 | //config: int "How long to wait between TERM and KILL (0 - send TERM only)" if FEATURE_KILL_REMOVED
|
---|
| 48 | //config: range 0 1024
|
---|
| 49 | //config: default 0
|
---|
| 50 | //config: depends on FEATURE_KILL_REMOVED
|
---|
| 51 | //config: help
|
---|
| 52 | //config: With nonzero setting, init sends TERM, forks, child waits N
|
---|
| 53 | //config: seconds, sends KILL and exits. Setting it too high is unwise
|
---|
| 54 | //config: (child will hang around for too long and could actually kill
|
---|
| 55 | //config: the wrong process!)
|
---|
| 56 | //config:
|
---|
| 57 | //config:config FEATURE_INIT_SCTTY
|
---|
| 58 | //config: bool "Run commands with leading dash with controlling tty"
|
---|
| 59 | //config: default y
|
---|
[3621] | 60 | //config: depends on INIT || LINUXRC
|
---|
[2725] | 61 | //config: help
|
---|
| 62 | //config: If this option is enabled, init will try to give a controlling
|
---|
| 63 | //config: tty to any command which has leading hyphen (often it's "-/bin/sh").
|
---|
| 64 | //config: More precisely, init will do "ioctl(STDIN_FILENO, TIOCSCTTY, 0)".
|
---|
| 65 | //config: If device attached to STDIN_FILENO can be a ctty but is not yet
|
---|
| 66 | //config: a ctty for other session, it will become this process' ctty.
|
---|
| 67 | //config: This is not the traditional init behavour, but is often what you want
|
---|
| 68 | //config: in an embedded system where the console is only accessed during
|
---|
| 69 | //config: development or for maintenance.
|
---|
| 70 | //config: NB: using cttyhack applet may work better.
|
---|
| 71 | //config:
|
---|
| 72 | //config:config FEATURE_INIT_SYSLOG
|
---|
| 73 | //config: bool "Enable init to write to syslog"
|
---|
| 74 | //config: default y
|
---|
[3621] | 75 | //config: depends on INIT || LINUXRC
|
---|
[2725] | 76 | //config:
|
---|
| 77 | //config:config FEATURE_EXTRA_QUIET
|
---|
| 78 | //config: bool "Be _extra_ quiet on boot"
|
---|
| 79 | //config: default y
|
---|
[3621] | 80 | //config: depends on INIT || LINUXRC
|
---|
[2725] | 81 | //config: help
|
---|
| 82 | //config: Prevent init from logging some messages to the console during boot.
|
---|
| 83 | //config:
|
---|
| 84 | //config:config FEATURE_INIT_COREDUMPS
|
---|
| 85 | //config: bool "Support dumping core for child processes (debugging only)"
|
---|
| 86 | //config: default y
|
---|
[3621] | 87 | //config: depends on INIT || LINUXRC
|
---|
[2725] | 88 | //config: help
|
---|
| 89 | //config: If this option is enabled and the file /.init_enable_core
|
---|
| 90 | //config: exists, then init will call setrlimit() to allow unlimited
|
---|
| 91 | //config: core file sizes. If this option is disabled, processes
|
---|
| 92 | //config: will not generate any core files.
|
---|
| 93 | //config:
|
---|
| 94 | //config:config INIT_TERMINAL_TYPE
|
---|
| 95 | //config: string "Initial terminal type"
|
---|
| 96 | //config: default "linux"
|
---|
[3621] | 97 | //config: depends on INIT || LINUXRC
|
---|
[2725] | 98 | //config: help
|
---|
| 99 | //config: This is the initial value set by init for the TERM environment
|
---|
| 100 | //config: variable. This variable is used by programs which make use of
|
---|
| 101 | //config: extended terminal capabilities.
|
---|
| 102 | //config:
|
---|
| 103 | //config: Note that on Linux, init attempts to detect serial terminal and
|
---|
| 104 | //config: sets TERM to "vt102" if one is found.
|
---|
[3621] | 105 | //config:
|
---|
| 106 | //config:config FEATURE_INIT_MODIFY_CMDLINE
|
---|
| 107 | //config: bool "Modify the command-line to \"init\""
|
---|
| 108 | //config: default y
|
---|
| 109 | //config: depends on INIT || LINUXRC
|
---|
| 110 | //config: help
|
---|
| 111 | //config: When launched as PID 1 and after parsing its arguments, init
|
---|
| 112 | //config: wipes all the arguments but argv[0] and rewrites argv[0] to
|
---|
| 113 | //config: contain only "init", so that its command-line appears solely as
|
---|
| 114 | //config: "init" in tools such as ps.
|
---|
| 115 | //config: If this option is set to Y, init will keep its original behavior,
|
---|
| 116 | //config: otherwise, all the arguments including argv[0] will be preserved,
|
---|
| 117 | //config: be they parsed or ignored by init.
|
---|
| 118 | //config: The original command-line used to launch init can then be
|
---|
| 119 | //config: retrieved in /proc/1/cmdline on Linux, for example.
|
---|
[2725] | 120 |
|
---|
[3621] | 121 | //applet:IF_INIT(APPLET(init, BB_DIR_SBIN, BB_SUID_DROP))
|
---|
| 122 | //applet:IF_LINUXRC(APPLET_ODDNAME(linuxrc, init, BB_DIR_ROOT, BB_SUID_DROP, linuxrc))
|
---|
| 123 |
|
---|
| 124 | //kbuild:lib-$(CONFIG_INIT) += init.o
|
---|
| 125 | //kbuild:lib-$(CONFIG_LINUXRC) += init.o
|
---|
| 126 |
|
---|
[3232] | 127 | #define DEBUG_SEGV_HANDLER 0
|
---|
| 128 |
|
---|
[1765] | 129 | #include "libbb.h"
|
---|
[2725] | 130 | #include <syslog.h>
|
---|
| 131 | #include <sys/resource.h>
|
---|
| 132 | #ifdef __linux__
|
---|
[3232] | 133 | # include <linux/vt.h>
|
---|
| 134 | # include <sys/sysinfo.h>
|
---|
[2725] | 135 | #endif
|
---|
| 136 | #include "reboot.h" /* reboot() constants */
|
---|
[821] | 137 |
|
---|
[3232] | 138 | #if DEBUG_SEGV_HANDLER
|
---|
| 139 | # undef _GNU_SOURCE
|
---|
| 140 | # define _GNU_SOURCE 1
|
---|
| 141 | # undef __USE_GNU
|
---|
| 142 | # define __USE_GNU 1
|
---|
| 143 | # include <execinfo.h>
|
---|
| 144 | # include <sys/ucontext.h>
|
---|
| 145 | #endif
|
---|
| 146 |
|
---|
[2725] | 147 | /* Used only for sanitizing purposes in set_sane_term() below. On systems where
|
---|
| 148 | * the baud rate is stored in a separate field, we can safely disable them. */
|
---|
| 149 | #ifndef CBAUD
|
---|
| 150 | # define CBAUD 0
|
---|
| 151 | # define CBAUDEX 0
|
---|
[821] | 152 | #endif
|
---|
| 153 |
|
---|
[2725] | 154 | /* Was a CONFIG_xxx option. A lot of people were building
|
---|
| 155 | * not fully functional init by switching it on! */
|
---|
| 156 | #define DEBUG_INIT 0
|
---|
| 157 |
|
---|
[1765] | 158 | #define CONSOLE_NAME_SIZE 32
|
---|
[821] | 159 |
|
---|
[2725] | 160 | /* Default sysinit script. */
|
---|
[821] | 161 | #ifndef INIT_SCRIPT
|
---|
[3621] | 162 | # define INIT_SCRIPT "/etc/init.d/rcS"
|
---|
[821] | 163 | #endif
|
---|
| 164 |
|
---|
[2725] | 165 | /* Each type of actions can appear many times. They will be
|
---|
| 166 | * handled in order. RESTART is an exception, only 1st is used.
|
---|
| 167 | */
|
---|
| 168 | /* Start these actions first and wait for completion */
|
---|
| 169 | #define SYSINIT 0x01
|
---|
| 170 | /* Start these after SYSINIT and wait for completion */
|
---|
| 171 | #define WAIT 0x02
|
---|
| 172 | /* Start these after WAIT and *dont* wait for completion */
|
---|
| 173 | #define ONCE 0x04
|
---|
| 174 | /*
|
---|
| 175 | * NB: while SYSINIT/WAIT/ONCE are being processed,
|
---|
| 176 | * SIGHUP ("reread /etc/inittab") will be processed only after
|
---|
| 177 | * each group of actions. If new inittab adds, say, a SYSINIT action,
|
---|
| 178 | * it will not be run, since init is already "past SYSINIT stage".
|
---|
| 179 | */
|
---|
| 180 | /* Start these after ONCE are started, restart on exit */
|
---|
| 181 | #define RESPAWN 0x08
|
---|
| 182 | /* Like RESPAWN, but wait for <Enter> to be pressed on tty */
|
---|
| 183 | #define ASKFIRST 0x10
|
---|
| 184 | /*
|
---|
| 185 | * Start these on SIGINT, and wait for completion.
|
---|
| 186 | * Then go back to respawning RESPAWN and ASKFIRST actions.
|
---|
| 187 | * NB: kernel sends SIGINT to us if Ctrl-Alt-Del was pressed.
|
---|
| 188 | */
|
---|
| 189 | #define CTRLALTDEL 0x20
|
---|
| 190 | /*
|
---|
| 191 | * Start these before killing all processes in preparation for
|
---|
| 192 | * running RESTART actions or doing low-level halt/reboot/poweroff
|
---|
| 193 | * (initiated by SIGUSR1/SIGTERM/SIGUSR2).
|
---|
| 194 | * Wait for completion before proceeding.
|
---|
| 195 | */
|
---|
| 196 | #define SHUTDOWN 0x40
|
---|
| 197 | /*
|
---|
| 198 | * exec() on SIGQUIT. SHUTDOWN actions are started and waited for,
|
---|
| 199 | * then all processes are killed, then init exec's 1st RESTART action,
|
---|
| 200 | * replacing itself by it. If no RESTART action specified,
|
---|
| 201 | * SIGQUIT has no effect.
|
---|
| 202 | */
|
---|
| 203 | #define RESTART 0x80
|
---|
[821] | 204 |
|
---|
| 205 |
|
---|
[2725] | 206 | /* A linked list of init_actions, to be read from inittab */
|
---|
[821] | 207 | struct init_action {
|
---|
[1765] | 208 | struct init_action *next;
|
---|
[821] | 209 | pid_t pid;
|
---|
[2725] | 210 | uint8_t action_type;
|
---|
[1765] | 211 | char terminal[CONSOLE_NAME_SIZE];
|
---|
[3621] | 212 | char command[1];
|
---|
[821] | 213 | };
|
---|
| 214 |
|
---|
| 215 | static struct init_action *init_action_list = NULL;
|
---|
| 216 |
|
---|
[1765] | 217 | static const char *log_console = VC_5;
|
---|
[821] | 218 |
|
---|
| 219 | enum {
|
---|
[1765] | 220 | L_LOG = 0x1,
|
---|
| 221 | L_CONSOLE = 0x2,
|
---|
[821] | 222 | };
|
---|
| 223 |
|
---|
| 224 | /* Print a message to the specified device.
|
---|
[2725] | 225 | * "where" may be bitwise-or'd from L_LOG | L_CONSOLE
|
---|
| 226 | * NB: careful, we can be called after vfork!
|
---|
| 227 | */
|
---|
| 228 | #define dbg_message(...) do { if (DEBUG_INIT) message(__VA_ARGS__); } while (0)
|
---|
| 229 | static void message(int where, const char *fmt, ...)
|
---|
[821] | 230 | __attribute__ ((format(printf, 2, 3)));
|
---|
[2725] | 231 | static void message(int where, const char *fmt, ...)
|
---|
[821] | 232 | {
|
---|
[1765] | 233 | va_list arguments;
|
---|
[2725] | 234 | unsigned l;
|
---|
[1765] | 235 | char msg[128];
|
---|
| 236 |
|
---|
[821] | 237 | msg[0] = '\r';
|
---|
[1765] | 238 | va_start(arguments, fmt);
|
---|
[2725] | 239 | l = 1 + vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments);
|
---|
[3621] | 240 | if (l > sizeof(msg) - 2)
|
---|
| 241 | l = sizeof(msg) - 2;
|
---|
[1765] | 242 | va_end(arguments);
|
---|
[821] | 243 |
|
---|
[1765] | 244 | #if ENABLE_FEATURE_INIT_SYSLOG
|
---|
[2725] | 245 | msg[l] = '\0';
|
---|
| 246 | if (where & L_LOG) {
|
---|
| 247 | /* Log the message to syslogd */
|
---|
[1765] | 248 | openlog(applet_name, 0, LOG_DAEMON);
|
---|
[2725] | 249 | /* don't print "\r" */
|
---|
| 250 | syslog(LOG_INFO, "%s", msg + 1);
|
---|
[821] | 251 | closelog();
|
---|
| 252 | }
|
---|
| 253 | msg[l++] = '\n';
|
---|
[1765] | 254 | msg[l] = '\0';
|
---|
[821] | 255 | #else
|
---|
[2725] | 256 | {
|
---|
| 257 | static int log_fd = -1;
|
---|
| 258 |
|
---|
| 259 | msg[l++] = '\n';
|
---|
| 260 | msg[l] = '\0';
|
---|
| 261 | /* Take full control of the log tty, and never close it.
|
---|
| 262 | * It's mine, all mine! Muhahahaha! */
|
---|
| 263 | if (log_fd < 0) {
|
---|
| 264 | if (!log_console) {
|
---|
| 265 | log_fd = STDERR_FILENO;
|
---|
[1765] | 266 | } else {
|
---|
[2725] | 267 | log_fd = device_open(log_console, O_WRONLY | O_NONBLOCK | O_NOCTTY);
|
---|
| 268 | if (log_fd < 0) {
|
---|
| 269 | bb_error_msg("can't log to %s", log_console);
|
---|
| 270 | where = L_CONSOLE;
|
---|
| 271 | } else {
|
---|
| 272 | close_on_exec_on(log_fd);
|
---|
| 273 | }
|
---|
[1765] | 274 | }
|
---|
[821] | 275 | }
|
---|
[2725] | 276 | if (where & L_LOG) {
|
---|
| 277 | full_write(log_fd, msg, l);
|
---|
| 278 | if (log_fd == STDERR_FILENO)
|
---|
| 279 | return; /* don't print dup messages */
|
---|
| 280 | }
|
---|
[821] | 281 | }
|
---|
| 282 | #endif
|
---|
| 283 |
|
---|
[2725] | 284 | if (where & L_CONSOLE) {
|
---|
[1765] | 285 | /* Send console messages to console so people will see them. */
|
---|
[2725] | 286 | full_write(STDERR_FILENO, msg, l);
|
---|
[821] | 287 | }
|
---|
| 288 | }
|
---|
| 289 |
|
---|
[2725] | 290 | static void console_init(void)
|
---|
| 291 | {
|
---|
| 292 | #ifdef VT_OPENQRY
|
---|
| 293 | int vtno;
|
---|
| 294 | #endif
|
---|
| 295 | char *s;
|
---|
| 296 |
|
---|
| 297 | s = getenv("CONSOLE");
|
---|
| 298 | if (!s)
|
---|
| 299 | s = getenv("console");
|
---|
| 300 | if (s) {
|
---|
| 301 | int fd = open(s, O_RDWR | O_NONBLOCK | O_NOCTTY);
|
---|
| 302 | if (fd >= 0) {
|
---|
| 303 | dup2(fd, STDIN_FILENO);
|
---|
| 304 | dup2(fd, STDOUT_FILENO);
|
---|
| 305 | xmove_fd(fd, STDERR_FILENO);
|
---|
| 306 | }
|
---|
| 307 | dbg_message(L_LOG, "console='%s'", s);
|
---|
| 308 | } else {
|
---|
| 309 | /* Make sure fd 0,1,2 are not closed
|
---|
| 310 | * (so that they won't be used by future opens) */
|
---|
| 311 | bb_sanitize_stdio();
|
---|
| 312 | // Users report problems
|
---|
| 313 | // /* Make sure init can't be blocked by writing to stderr */
|
---|
| 314 | // fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK);
|
---|
| 315 | }
|
---|
| 316 |
|
---|
| 317 | s = getenv("TERM");
|
---|
| 318 | #ifdef VT_OPENQRY
|
---|
| 319 | if (ioctl(STDIN_FILENO, VT_OPENQRY, &vtno) != 0) {
|
---|
| 320 | /* Not a linux terminal, probably serial console.
|
---|
| 321 | * Force the TERM setting to vt102
|
---|
| 322 | * if TERM is set to linux (the default) */
|
---|
| 323 | if (!s || strcmp(s, "linux") == 0)
|
---|
| 324 | putenv((char*)"TERM=vt102");
|
---|
| 325 | if (!ENABLE_FEATURE_INIT_SYSLOG)
|
---|
| 326 | log_console = NULL;
|
---|
| 327 | } else
|
---|
| 328 | #endif
|
---|
| 329 | if (!s)
|
---|
| 330 | putenv((char*)"TERM=" CONFIG_INIT_TERMINAL_TYPE);
|
---|
| 331 | }
|
---|
| 332 |
|
---|
| 333 | /* Set terminal settings to reasonable defaults.
|
---|
| 334 | * NB: careful, we can be called after vfork! */
|
---|
[1765] | 335 | static void set_sane_term(void)
|
---|
[821] | 336 | {
|
---|
| 337 | struct termios tty;
|
---|
| 338 |
|
---|
| 339 | tcgetattr(STDIN_FILENO, &tty);
|
---|
| 340 |
|
---|
| 341 | /* set control chars */
|
---|
| 342 | tty.c_cc[VINTR] = 3; /* C-c */
|
---|
| 343 | tty.c_cc[VQUIT] = 28; /* C-\ */
|
---|
| 344 | tty.c_cc[VERASE] = 127; /* C-? */
|
---|
| 345 | tty.c_cc[VKILL] = 21; /* C-u */
|
---|
| 346 | tty.c_cc[VEOF] = 4; /* C-d */
|
---|
| 347 | tty.c_cc[VSTART] = 17; /* C-q */
|
---|
| 348 | tty.c_cc[VSTOP] = 19; /* C-s */
|
---|
| 349 | tty.c_cc[VSUSP] = 26; /* C-z */
|
---|
| 350 |
|
---|
[2725] | 351 | #ifdef __linux__
|
---|
| 352 | /* use line discipline 0 */
|
---|
[821] | 353 | tty.c_line = 0;
|
---|
[2725] | 354 | #endif
|
---|
[821] | 355 |
|
---|
| 356 | /* Make it be sane */
|
---|
[2725] | 357 | #ifndef CRTSCTS
|
---|
| 358 | # define CRTSCTS 0
|
---|
| 359 | #endif
|
---|
| 360 | /* added CRTSCTS to fix Debian bug 528560 */
|
---|
| 361 | tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD | CRTSCTS;
|
---|
[821] | 362 | tty.c_cflag |= CREAD | HUPCL | CLOCAL;
|
---|
| 363 |
|
---|
| 364 | /* input modes */
|
---|
| 365 | tty.c_iflag = ICRNL | IXON | IXOFF;
|
---|
| 366 |
|
---|
| 367 | /* output modes */
|
---|
| 368 | tty.c_oflag = OPOST | ONLCR;
|
---|
| 369 |
|
---|
| 370 | /* local modes */
|
---|
[2725] | 371 | tty.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
|
---|
[821] | 372 |
|
---|
[2725] | 373 | tcsetattr_stdin_TCSANOW(&tty);
|
---|
[821] | 374 | }
|
---|
| 375 |
|
---|
[2725] | 376 | /* Open the new terminal device.
|
---|
| 377 | * NB: careful, we can be called after vfork! */
|
---|
| 378 | static int open_stdio_to_tty(const char* tty_name)
|
---|
[821] | 379 | {
|
---|
[1765] | 380 | /* empty tty_name means "use init's tty", else... */
|
---|
| 381 | if (tty_name[0]) {
|
---|
[2725] | 382 | int fd;
|
---|
| 383 |
|
---|
| 384 | close(STDIN_FILENO);
|
---|
| 385 | /* fd can be only < 0 or 0: */
|
---|
| 386 | fd = device_open(tty_name, O_RDWR);
|
---|
| 387 | if (fd) {
|
---|
| 388 | message(L_LOG | L_CONSOLE, "can't open %s: %s",
|
---|
[1765] | 389 | tty_name, strerror(errno));
|
---|
[2725] | 390 | return 0; /* failure */
|
---|
[1765] | 391 | }
|
---|
[2725] | 392 | dup2(STDIN_FILENO, STDOUT_FILENO);
|
---|
| 393 | dup2(STDIN_FILENO, STDERR_FILENO);
|
---|
[821] | 394 | }
|
---|
[1765] | 395 | set_sane_term();
|
---|
[2725] | 396 | return 1; /* success */
|
---|
[821] | 397 | }
|
---|
| 398 |
|
---|
[2725] | 399 | static void reset_sighandlers_and_unblock_sigs(void)
|
---|
[821] | 400 | {
|
---|
[2725] | 401 | bb_signals(0
|
---|
| 402 | + (1 << SIGUSR1)
|
---|
| 403 | + (1 << SIGUSR2)
|
---|
| 404 | + (1 << SIGTERM)
|
---|
| 405 | + (1 << SIGQUIT)
|
---|
| 406 | + (1 << SIGINT)
|
---|
| 407 | + (1 << SIGHUP)
|
---|
| 408 | + (1 << SIGTSTP)
|
---|
| 409 | + (1 << SIGSTOP)
|
---|
| 410 | , SIG_DFL);
|
---|
| 411 | sigprocmask_allsigs(SIG_UNBLOCK);
|
---|
| 412 | }
|
---|
[821] | 413 |
|
---|
[2725] | 414 | /* Wrapper around exec:
|
---|
[3621] | 415 | * Takes string.
|
---|
[2725] | 416 | * If chars like '>' detected, execs '[-]/bin/sh -c "exec ......."'.
|
---|
| 417 | * Otherwise splits words on whitespace, deals with leading dash,
|
---|
| 418 | * and uses plain exec().
|
---|
| 419 | * NB: careful, we can be called after vfork!
|
---|
| 420 | */
|
---|
| 421 | static void init_exec(const char *command)
|
---|
| 422 | {
|
---|
[3621] | 423 | /* +8 allows to write VLA sizes below more efficiently: */
|
---|
| 424 | unsigned command_size = strlen(command) + 8;
|
---|
| 425 | /* strlen(command) + strlen("exec ")+1: */
|
---|
| 426 | char buf[command_size];
|
---|
| 427 | /* strlen(command) / 2 + 4: */
|
---|
| 428 | char *cmd[command_size / 2];
|
---|
| 429 | int dash;
|
---|
[821] | 430 |
|
---|
[3621] | 431 | dash = (command[0] == '-' /* maybe? && command[1] == '/' */);
|
---|
[3232] | 432 | command += dash;
|
---|
| 433 |
|
---|
[1765] | 434 | /* See if any special /bin/sh requiring characters are present */
|
---|
[2725] | 435 | if (strpbrk(command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
|
---|
[3232] | 436 | sprintf(buf, "exec %s", command); /* excluding "-" */
|
---|
[2725] | 437 | /* NB: LIBBB_DEFAULT_LOGIN_SHELL define has leading dash */
|
---|
| 438 | cmd[0] = (char*)(LIBBB_DEFAULT_LOGIN_SHELL + !dash);
|
---|
[1765] | 439 | cmd[1] = (char*)"-c";
|
---|
[2725] | 440 | cmd[2] = buf;
|
---|
[1765] | 441 | cmd[3] = NULL;
|
---|
[3232] | 442 | command = LIBBB_DEFAULT_LOGIN_SHELL + 1;
|
---|
[1765] | 443 | } else {
|
---|
| 444 | /* Convert command (char*) into cmd (char**, one word per string) */
|
---|
[2725] | 445 | char *word, *next;
|
---|
| 446 | int i = 0;
|
---|
[3232] | 447 | next = strcpy(buf, command - dash); /* command including "-" */
|
---|
| 448 | command = next + dash;
|
---|
[2725] | 449 | while ((word = strsep(&next, " \t")) != NULL) {
|
---|
| 450 | if (*word != '\0') { /* not two spaces/tabs together? */
|
---|
| 451 | cmd[i] = word;
|
---|
[1765] | 452 | i++;
|
---|
[821] | 453 | }
|
---|
| 454 | }
|
---|
[1765] | 455 | cmd[i] = NULL;
|
---|
| 456 | }
|
---|
[2725] | 457 | /* If we saw leading "-", it is interactive shell.
|
---|
| 458 | * Try harder to give it a controlling tty.
|
---|
[3232] | 459 | */
|
---|
| 460 | if (ENABLE_FEATURE_INIT_SCTTY && dash) {
|
---|
[2725] | 461 | /* _Attempt_ to make stdin a controlling tty. */
|
---|
[3232] | 462 | ioctl(STDIN_FILENO, TIOCSCTTY, 0 /*only try, don't steal*/);
|
---|
[2725] | 463 | }
|
---|
[3232] | 464 | /* Here command never contains the dash, cmd[0] might */
|
---|
| 465 | BB_EXECVP(command, cmd);
|
---|
| 466 | message(L_LOG | L_CONSOLE, "can't run '%s': %s", command, strerror(errno));
|
---|
[2725] | 467 | /* returns if execvp fails */
|
---|
| 468 | }
|
---|
[821] | 469 |
|
---|
[2725] | 470 | /* Used only by run_actions */
|
---|
| 471 | static pid_t run(const struct init_action *a)
|
---|
| 472 | {
|
---|
| 473 | pid_t pid;
|
---|
[821] | 474 |
|
---|
[2725] | 475 | /* Careful: don't be affected by a signal in vforked child */
|
---|
| 476 | sigprocmask_allsigs(SIG_BLOCK);
|
---|
| 477 | if (BB_MMU && (a->action_type & ASKFIRST))
|
---|
| 478 | pid = fork();
|
---|
| 479 | else
|
---|
| 480 | pid = vfork();
|
---|
| 481 | if (pid < 0)
|
---|
| 482 | message(L_LOG | L_CONSOLE, "can't fork");
|
---|
| 483 | if (pid) {
|
---|
| 484 | sigprocmask_allsigs(SIG_UNBLOCK);
|
---|
| 485 | return pid; /* Parent or error */
|
---|
| 486 | }
|
---|
[821] | 487 |
|
---|
[2725] | 488 | /* Child */
|
---|
[821] | 489 |
|
---|
[2725] | 490 | /* Reset signal handlers that were set by the parent process */
|
---|
| 491 | reset_sighandlers_and_unblock_sigs();
|
---|
[821] | 492 |
|
---|
[2725] | 493 | /* Create a new session and make ourself the process group leader */
|
---|
| 494 | setsid();
|
---|
| 495 |
|
---|
| 496 | /* Open the new terminal device */
|
---|
| 497 | if (!open_stdio_to_tty(a->terminal))
|
---|
| 498 | _exit(EXIT_FAILURE);
|
---|
| 499 |
|
---|
| 500 | /* NB: on NOMMU we can't wait for input in child, so
|
---|
| 501 | * "askfirst" will work the same as "respawn". */
|
---|
| 502 | if (BB_MMU && (a->action_type & ASKFIRST)) {
|
---|
[1765] | 503 | static const char press_enter[] ALIGN1 =
|
---|
| 504 | #ifdef CUSTOMIZED_BANNER
|
---|
| 505 | #include CUSTOMIZED_BANNER
|
---|
[821] | 506 | #endif
|
---|
[1765] | 507 | "\nPlease press Enter to activate this console. ";
|
---|
| 508 | char c;
|
---|
| 509 | /*
|
---|
| 510 | * Save memory by not exec-ing anything large (like a shell)
|
---|
| 511 | * before the user wants it. This is critical if swap is not
|
---|
| 512 | * enabled and the system has low memory. Generally this will
|
---|
| 513 | * be run on the second virtual console, and the first will
|
---|
| 514 | * be allowed to start a shell or whatever an init script
|
---|
| 515 | * specifies.
|
---|
| 516 | */
|
---|
[2725] | 517 | dbg_message(L_LOG, "waiting for enter to start '%s'"
|
---|
[1765] | 518 | "(pid %d, tty '%s')\n",
|
---|
[2725] | 519 | a->command, getpid(), a->terminal);
|
---|
| 520 | full_write(STDOUT_FILENO, press_enter, sizeof(press_enter) - 1);
|
---|
| 521 | while (safe_read(STDIN_FILENO, &c, 1) == 1 && c != '\n')
|
---|
| 522 | continue;
|
---|
[1765] | 523 | }
|
---|
[821] | 524 |
|
---|
[2725] | 525 | /*
|
---|
| 526 | * When a file named /.init_enable_core exists, setrlimit is called
|
---|
| 527 | * before processes are spawned to set core file size as unlimited.
|
---|
| 528 | * This is for debugging only. Don't use this is production, unless
|
---|
| 529 | * you want core dumps lying about....
|
---|
| 530 | */
|
---|
| 531 | if (ENABLE_FEATURE_INIT_COREDUMPS) {
|
---|
| 532 | if (access("/.init_enable_core", F_OK) == 0) {
|
---|
[1765] | 533 | struct rlimit limit;
|
---|
| 534 | limit.rlim_cur = RLIM_INFINITY;
|
---|
| 535 | limit.rlim_max = RLIM_INFINITY;
|
---|
| 536 | setrlimit(RLIMIT_CORE, &limit);
|
---|
[821] | 537 | }
|
---|
[1765] | 538 | }
|
---|
[2725] | 539 |
|
---|
| 540 | /* Log the process name and args */
|
---|
| 541 | message(L_LOG, "starting pid %d, tty '%s': '%s'",
|
---|
[3232] | 542 | getpid(), a->terminal, a->command);
|
---|
[2725] | 543 |
|
---|
[1765] | 544 | /* Now run it. The new program will take over this PID,
|
---|
| 545 | * so nothing further in init.c should be run. */
|
---|
[2725] | 546 | init_exec(a->command);
|
---|
[1765] | 547 | /* We're still here? Some error happened. */
|
---|
| 548 | _exit(-1);
|
---|
[821] | 549 | }
|
---|
| 550 |
|
---|
[2725] | 551 | static struct init_action *mark_terminated(pid_t pid)
|
---|
[821] | 552 | {
|
---|
[2725] | 553 | struct init_action *a;
|
---|
[821] | 554 |
|
---|
[2725] | 555 | if (pid > 0) {
|
---|
[3621] | 556 | update_utmp_DEAD_PROCESS(pid);
|
---|
[2725] | 557 | for (a = init_action_list; a; a = a->next) {
|
---|
| 558 | if (a->pid == pid) {
|
---|
| 559 | a->pid = 0;
|
---|
| 560 | return a;
|
---|
| 561 | }
|
---|
| 562 | }
|
---|
| 563 | }
|
---|
| 564 | return NULL;
|
---|
| 565 | }
|
---|
| 566 |
|
---|
| 567 | static void waitfor(pid_t pid)
|
---|
| 568 | {
|
---|
| 569 | /* waitfor(run(x)): protect against failed fork inside run() */
|
---|
| 570 | if (pid <= 0)
|
---|
| 571 | return;
|
---|
| 572 |
|
---|
| 573 | /* Wait for any child (prevent zombies from exiting orphaned processes)
|
---|
| 574 | * but exit the loop only when specified one has exited. */
|
---|
[821] | 575 | while (1) {
|
---|
[2725] | 576 | pid_t wpid = wait(NULL);
|
---|
| 577 | mark_terminated(wpid);
|
---|
| 578 | /* Unsafe. SIGTSTP handler might have wait'ed it already */
|
---|
| 579 | /*if (wpid == pid) break;*/
|
---|
| 580 | /* More reliable: */
|
---|
| 581 | if (kill(pid, 0))
|
---|
[821] | 582 | break;
|
---|
[2725] | 583 | }
|
---|
| 584 | }
|
---|
| 585 |
|
---|
| 586 | /* Run all commands of a particular type */
|
---|
| 587 | static void run_actions(int action_type)
|
---|
| 588 | {
|
---|
| 589 | struct init_action *a;
|
---|
| 590 |
|
---|
| 591 | for (a = init_action_list; a; a = a->next) {
|
---|
| 592 | if (!(a->action_type & action_type))
|
---|
| 593 | continue;
|
---|
| 594 |
|
---|
| 595 | if (a->action_type & (SYSINIT | WAIT | ONCE | CTRLALTDEL | SHUTDOWN)) {
|
---|
| 596 | pid_t pid = run(a);
|
---|
| 597 | if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN))
|
---|
| 598 | waitfor(pid);
|
---|
| 599 | }
|
---|
| 600 | if (a->action_type & (RESPAWN | ASKFIRST)) {
|
---|
| 601 | /* Only run stuff with pid == 0. If pid != 0,
|
---|
| 602 | * it is already running
|
---|
| 603 | */
|
---|
| 604 | if (a->pid == 0)
|
---|
| 605 | a->pid = run(a);
|
---|
| 606 | }
|
---|
| 607 | }
|
---|
| 608 | }
|
---|
| 609 |
|
---|
| 610 | static void new_init_action(uint8_t action_type, const char *command, const char *cons)
|
---|
| 611 | {
|
---|
| 612 | struct init_action *a, **nextp;
|
---|
| 613 |
|
---|
| 614 | /* Scenario:
|
---|
| 615 | * old inittab:
|
---|
| 616 | * ::shutdown:umount -a -r
|
---|
| 617 | * ::shutdown:swapoff -a
|
---|
| 618 | * new inittab:
|
---|
| 619 | * ::shutdown:swapoff -a
|
---|
| 620 | * ::shutdown:umount -a -r
|
---|
| 621 | * On reload, we must ensure entries end up in correct order.
|
---|
| 622 | * To achieve that, if we find a matching entry, we move it
|
---|
| 623 | * to the end.
|
---|
| 624 | */
|
---|
| 625 | nextp = &init_action_list;
|
---|
| 626 | while ((a = *nextp) != NULL) {
|
---|
[3232] | 627 | /* Don't enter action if it's already in the list.
|
---|
[2725] | 628 | * This prevents losing running RESPAWNs.
|
---|
| 629 | */
|
---|
| 630 | if (strcmp(a->command, command) == 0
|
---|
| 631 | && strcmp(a->terminal, cons) == 0
|
---|
| 632 | ) {
|
---|
| 633 | /* Remove from list */
|
---|
| 634 | *nextp = a->next;
|
---|
| 635 | /* Find the end of the list */
|
---|
| 636 | while (*nextp != NULL)
|
---|
| 637 | nextp = &(*nextp)->next;
|
---|
| 638 | a->next = NULL;
|
---|
[3232] | 639 | goto append;
|
---|
[821] | 640 | }
|
---|
[2725] | 641 | nextp = &a->next;
|
---|
[821] | 642 | }
|
---|
[2725] | 643 |
|
---|
[3621] | 644 | a = xzalloc(sizeof(*a) + strlen(command));
|
---|
[3232] | 645 |
|
---|
[2725] | 646 | /* Append to the end of the list */
|
---|
[3232] | 647 | append:
|
---|
[2725] | 648 | *nextp = a;
|
---|
| 649 | a->action_type = action_type;
|
---|
[3621] | 650 | strcpy(a->command, command);
|
---|
[2725] | 651 | safe_strncpy(a->terminal, cons, sizeof(a->terminal));
|
---|
[3621] | 652 | dbg_message(L_LOG | L_CONSOLE, "command='%s' action=%x tty='%s'\n",
|
---|
[2725] | 653 | a->command, a->action_type, a->terminal);
|
---|
[821] | 654 | }
|
---|
| 655 |
|
---|
[2725] | 656 | /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
|
---|
| 657 | * then parse_inittab() simply adds in some default
|
---|
[3621] | 658 | * actions (i.e., runs INIT_SCRIPT and then starts a pair
|
---|
[2725] | 659 | * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
|
---|
| 660 | * _is_ defined, but /etc/inittab is missing, this
|
---|
| 661 | * results in the same set of default behaviors.
|
---|
| 662 | */
|
---|
| 663 | static void parse_inittab(void)
|
---|
[821] | 664 | {
|
---|
[2725] | 665 | #if ENABLE_FEATURE_USE_INITTAB
|
---|
| 666 | char *token[4];
|
---|
| 667 | parser_t *parser = config_open2("/etc/inittab", fopen_for_read);
|
---|
[821] | 668 |
|
---|
[2725] | 669 | if (parser == NULL)
|
---|
| 670 | #endif
|
---|
| 671 | {
|
---|
| 672 | /* No inittab file - set up some default behavior */
|
---|
[3621] | 673 | /* Sysinit */
|
---|
| 674 | new_init_action(SYSINIT, INIT_SCRIPT, "");
|
---|
| 675 | /* Askfirst shell on tty1-4 */
|
---|
| 676 | new_init_action(ASKFIRST, bb_default_login_shell, "");
|
---|
| 677 | //TODO: VC_1 instead of ""? "" is console -> ctty problems -> angry users
|
---|
| 678 | new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
|
---|
| 679 | new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
|
---|
| 680 | new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
|
---|
[2725] | 681 | /* Reboot on Ctrl-Alt-Del */
|
---|
| 682 | new_init_action(CTRLALTDEL, "reboot", "");
|
---|
| 683 | /* Umount all filesystems on halt/reboot */
|
---|
| 684 | new_init_action(SHUTDOWN, "umount -a -r", "");
|
---|
| 685 | /* Swapoff on halt/reboot */
|
---|
[3621] | 686 | new_init_action(SHUTDOWN, "swapoff -a", "");
|
---|
| 687 | /* Restart init when a QUIT is received */
|
---|
[2725] | 688 | new_init_action(RESTART, "init", "");
|
---|
| 689 | return;
|
---|
| 690 | }
|
---|
| 691 |
|
---|
| 692 | #if ENABLE_FEATURE_USE_INITTAB
|
---|
| 693 | /* optional_tty:ignored_runlevel:action:command
|
---|
| 694 | * Delims are not to be collapsed and need exactly 4 tokens
|
---|
| 695 | */
|
---|
| 696 | while (config_read(parser, token, 4, 0, "#:",
|
---|
| 697 | PARSE_NORMAL & ~(PARSE_TRIM | PARSE_COLLAPSE))) {
|
---|
| 698 | /* order must correspond to SYSINIT..RESTART constants */
|
---|
| 699 | static const char actions[] ALIGN1 =
|
---|
| 700 | "sysinit\0""wait\0""once\0""respawn\0""askfirst\0"
|
---|
| 701 | "ctrlaltdel\0""shutdown\0""restart\0";
|
---|
| 702 | int action;
|
---|
| 703 | char *tty = token[0];
|
---|
| 704 |
|
---|
| 705 | if (!token[3]) /* less than 4 tokens */
|
---|
| 706 | goto bad_entry;
|
---|
| 707 | action = index_in_strings(actions, token[2]);
|
---|
| 708 | if (action < 0 || !token[3][0]) /* token[3]: command */
|
---|
| 709 | goto bad_entry;
|
---|
| 710 | /* turn .*TTY -> /dev/TTY */
|
---|
| 711 | if (tty[0]) {
|
---|
| 712 | tty = concat_path_file("/dev/", skip_dev_pfx(tty));
|
---|
[821] | 713 | }
|
---|
[2725] | 714 | new_init_action(1 << action, token[3], tty);
|
---|
| 715 | if (tty[0])
|
---|
| 716 | free(tty);
|
---|
| 717 | continue;
|
---|
| 718 | bad_entry:
|
---|
| 719 | message(L_LOG | L_CONSOLE, "Bad inittab entry at line %d",
|
---|
| 720 | parser->lineno);
|
---|
[821] | 721 | }
|
---|
[2725] | 722 | config_close(parser);
|
---|
| 723 | #endif
|
---|
[821] | 724 | }
|
---|
| 725 |
|
---|
[2725] | 726 | static void pause_and_low_level_reboot(unsigned magic) NORETURN;
|
---|
| 727 | static void pause_and_low_level_reboot(unsigned magic)
|
---|
[821] | 728 | {
|
---|
| 729 | pid_t pid;
|
---|
[2725] | 730 |
|
---|
| 731 | /* Allow time for last message to reach serial console, etc */
|
---|
| 732 | sleep(1);
|
---|
| 733 |
|
---|
| 734 | /* We have to fork here, since the kernel calls do_exit(EXIT_SUCCESS)
|
---|
| 735 | * in linux/kernel/sys.c, which can cause the machine to panic when
|
---|
| 736 | * the init process exits... */
|
---|
[1765] | 737 | pid = vfork();
|
---|
| 738 | if (pid == 0) { /* child */
|
---|
[821] | 739 | reboot(magic);
|
---|
[2725] | 740 | _exit(EXIT_SUCCESS);
|
---|
[821] | 741 | }
|
---|
[2725] | 742 | while (1)
|
---|
| 743 | sleep(1);
|
---|
[821] | 744 | }
|
---|
| 745 |
|
---|
[2725] | 746 | static void run_shutdown_and_kill_processes(void)
|
---|
[821] | 747 | {
|
---|
[2725] | 748 | /* Run everything to be run at "shutdown". This is done _prior_
|
---|
[821] | 749 | * to killing everything, in case people wish to use scripts to
|
---|
| 750 | * shut things down gracefully... */
|
---|
| 751 | run_actions(SHUTDOWN);
|
---|
| 752 |
|
---|
[1765] | 753 | message(L_CONSOLE | L_LOG, "The system is going down NOW!");
|
---|
| 754 |
|
---|
[821] | 755 | /* Send signals to every process _except_ pid 1 */
|
---|
| 756 | kill(-1, SIGTERM);
|
---|
[2725] | 757 | message(L_CONSOLE | L_LOG, "Sent SIG%s to all processes", "TERM");
|
---|
[1765] | 758 | sync();
|
---|
[821] | 759 | sleep(1);
|
---|
| 760 |
|
---|
| 761 | kill(-1, SIGKILL);
|
---|
[2725] | 762 | message(L_CONSOLE, "Sent SIG%s to all processes", "KILL");
|
---|
[1765] | 763 | sync();
|
---|
[2725] | 764 | /*sleep(1); - callers take care about making a pause */
|
---|
[821] | 765 | }
|
---|
| 766 |
|
---|
[2725] | 767 | /* Signal handling by init:
|
---|
| 768 | *
|
---|
| 769 | * For process with PID==1, on entry kernel sets all signals to SIG_DFL
|
---|
| 770 | * and unmasks all signals. However, for process with PID==1,
|
---|
| 771 | * default action (SIG_DFL) on any signal is to ignore it,
|
---|
| 772 | * even for special signals SIGKILL and SIGCONT.
|
---|
| 773 | * Also, any signal can be caught or blocked.
|
---|
| 774 | * (but SIGSTOP is still handled specially, at least in 2.6.20)
|
---|
| 775 | *
|
---|
| 776 | * We install two kinds of handlers, "immediate" and "delayed".
|
---|
| 777 | *
|
---|
| 778 | * Immediate handlers execute at any time, even while, say, sysinit
|
---|
| 779 | * is running.
|
---|
| 780 | *
|
---|
| 781 | * Delayed handlers just set a flag variable. The variable is checked
|
---|
| 782 | * in the main loop and acted upon.
|
---|
| 783 | *
|
---|
| 784 | * halt/poweroff/reboot and restart have immediate handlers.
|
---|
| 785 | * They only traverse linked list of struct action's, never modify it,
|
---|
| 786 | * this should be safe to do even in signal handler. Also they
|
---|
| 787 | * never return.
|
---|
| 788 | *
|
---|
| 789 | * SIGSTOP and SIGTSTP have immediate handlers. They just wait
|
---|
| 790 | * for SIGCONT to happen.
|
---|
| 791 | *
|
---|
| 792 | * SIGHUP has a delayed handler, because modifying linked list
|
---|
| 793 | * of struct action's from a signal handler while it is manipulated
|
---|
| 794 | * by the program may be disastrous.
|
---|
| 795 | *
|
---|
| 796 | * Ctrl-Alt-Del has a delayed handler. Not a must, but allowing
|
---|
| 797 | * it to happen even somewhere inside "sysinit" would be a bit awkward.
|
---|
| 798 | *
|
---|
| 799 | * There is a tiny probability that SIGHUP and Ctrl-Alt-Del will collide
|
---|
| 800 | * and only one will be remembered and acted upon.
|
---|
| 801 | */
|
---|
[821] | 802 |
|
---|
[3621] | 803 | /* The SIGPWR/SIGUSR[12]/SIGTERM handler */
|
---|
[2725] | 804 | static void halt_reboot_pwoff(int sig) NORETURN;
|
---|
| 805 | static void halt_reboot_pwoff(int sig)
|
---|
[821] | 806 | {
|
---|
[1765] | 807 | const char *m;
|
---|
[2725] | 808 | unsigned rb;
|
---|
[821] | 809 |
|
---|
[2725] | 810 | /* We may call run() and it unmasks signals,
|
---|
| 811 | * including the one masked inside this signal handler.
|
---|
| 812 | * Testcase which would start multiple reboot scripts:
|
---|
| 813 | * while true; do reboot; done
|
---|
| 814 | * Preventing it:
|
---|
| 815 | */
|
---|
| 816 | reset_sighandlers_and_unblock_sigs();
|
---|
[821] | 817 |
|
---|
[2725] | 818 | run_shutdown_and_kill_processes();
|
---|
| 819 |
|
---|
[1765] | 820 | m = "halt";
|
---|
| 821 | rb = RB_HALT_SYSTEM;
|
---|
[821] | 822 | if (sig == SIGTERM) {
|
---|
| 823 | m = "reboot";
|
---|
| 824 | rb = RB_AUTOBOOT;
|
---|
| 825 | } else if (sig == SIGUSR2) {
|
---|
| 826 | m = "poweroff";
|
---|
| 827 | rb = RB_POWER_OFF;
|
---|
| 828 | }
|
---|
[2725] | 829 | message(L_CONSOLE, "Requesting system %s", m);
|
---|
| 830 | pause_and_low_level_reboot(rb);
|
---|
| 831 | /* not reached */
|
---|
[821] | 832 | }
|
---|
| 833 |
|
---|
[2725] | 834 | /* Handler for QUIT - exec "restart" action,
|
---|
| 835 | * else (no such action defined) do nothing */
|
---|
[3621] | 836 | static void exec_restart_action(void)
|
---|
[821] | 837 | {
|
---|
[2725] | 838 | struct init_action *a;
|
---|
[821] | 839 |
|
---|
[2725] | 840 | for (a = init_action_list; a; a = a->next) {
|
---|
| 841 | if (!(a->action_type & RESTART))
|
---|
| 842 | continue;
|
---|
[821] | 843 |
|
---|
[2725] | 844 | /* Starting from here, we won't return.
|
---|
| 845 | * Thus don't need to worry about preserving errno
|
---|
| 846 | * and such.
|
---|
| 847 | */
|
---|
[821] | 848 |
|
---|
[2725] | 849 | reset_sighandlers_and_unblock_sigs();
|
---|
[821] | 850 |
|
---|
[2725] | 851 | run_shutdown_and_kill_processes();
|
---|
[821] | 852 |
|
---|
[2725] | 853 | #ifdef RB_ENABLE_CAD
|
---|
| 854 | /* Allow Ctrl-Alt-Del to reboot the system.
|
---|
| 855 | * This is how kernel sets it up for init, we follow suit.
|
---|
| 856 | */
|
---|
| 857 | reboot(RB_ENABLE_CAD); /* misnomer */
|
---|
| 858 | #endif
|
---|
[821] | 859 |
|
---|
[2725] | 860 | if (open_stdio_to_tty(a->terminal)) {
|
---|
| 861 | dbg_message(L_CONSOLE, "Trying to re-exec %s", a->command);
|
---|
| 862 | /* Theoretically should be safe.
|
---|
| 863 | * But in practice, kernel bugs may leave
|
---|
| 864 | * unkillable processes, and wait() may block forever.
|
---|
| 865 | * Oh well. Hoping "new" init won't be too surprised
|
---|
| 866 | * by having children it didn't create.
|
---|
| 867 | */
|
---|
| 868 | //while (wait(NULL) > 0)
|
---|
| 869 | // continue;
|
---|
| 870 | init_exec(a->command);
|
---|
[821] | 871 | }
|
---|
[2725] | 872 | /* Open or exec failed */
|
---|
| 873 | pause_and_low_level_reboot(RB_HALT_SYSTEM);
|
---|
| 874 | /* not reached */
|
---|
[821] | 875 | }
|
---|
| 876 | }
|
---|
| 877 |
|
---|
[2725] | 878 | /* The SIGSTOP/SIGTSTP handler
|
---|
| 879 | * NB: inside it, all signals except SIGCONT are masked
|
---|
| 880 | * via appropriate setup in sigaction().
|
---|
| 881 | */
|
---|
| 882 | static void stop_handler(int sig UNUSED_PARAM)
|
---|
[821] | 883 | {
|
---|
[2725] | 884 | smallint saved_bb_got_signal;
|
---|
| 885 | int saved_errno;
|
---|
[821] | 886 |
|
---|
[2725] | 887 | saved_bb_got_signal = bb_got_signal;
|
---|
| 888 | saved_errno = errno;
|
---|
| 889 | signal(SIGCONT, record_signo);
|
---|
| 890 |
|
---|
| 891 | while (1) {
|
---|
| 892 | pid_t wpid;
|
---|
| 893 |
|
---|
| 894 | if (bb_got_signal == SIGCONT)
|
---|
[821] | 895 | break;
|
---|
[2725] | 896 | /* NB: this can accidentally wait() for a process
|
---|
| 897 | * which we waitfor() elsewhere! waitfor() must have
|
---|
| 898 | * code which is resilient against this.
|
---|
| 899 | */
|
---|
| 900 | wpid = wait_any_nohang(NULL);
|
---|
| 901 | mark_terminated(wpid);
|
---|
| 902 | sleep(1);
|
---|
[821] | 903 | }
|
---|
[2725] | 904 |
|
---|
| 905 | signal(SIGCONT, SIG_DFL);
|
---|
| 906 | errno = saved_errno;
|
---|
| 907 | bb_got_signal = saved_bb_got_signal;
|
---|
[821] | 908 | }
|
---|
| 909 |
|
---|
[2725] | 910 | #if ENABLE_FEATURE_USE_INITTAB
|
---|
| 911 | static void reload_inittab(void)
|
---|
[821] | 912 | {
|
---|
[2725] | 913 | struct init_action *a, **nextp;
|
---|
[821] | 914 |
|
---|
[2725] | 915 | message(L_LOG, "reloading /etc/inittab");
|
---|
[821] | 916 |
|
---|
[2725] | 917 | /* Disable old entries */
|
---|
| 918 | for (a = init_action_list; a; a = a->next)
|
---|
| 919 | a->action_type = 0;
|
---|
[821] | 920 |
|
---|
[2725] | 921 | /* Append new entries, or modify existing entries
|
---|
| 922 | * (incl. setting a->action_type) if cmd and device name
|
---|
| 923 | * match new ones. End result: only entries with
|
---|
| 924 | * a->action_type == 0 are stale.
|
---|
| 925 | */
|
---|
| 926 | parse_inittab();
|
---|
[821] | 927 |
|
---|
[2725] | 928 | #if ENABLE_FEATURE_KILL_REMOVED
|
---|
| 929 | /* Kill stale entries */
|
---|
| 930 | /* Be nice and send SIGTERM first */
|
---|
| 931 | for (a = init_action_list; a; a = a->next)
|
---|
| 932 | if (a->action_type == 0 && a->pid != 0)
|
---|
| 933 | kill(a->pid, SIGTERM);
|
---|
| 934 | if (CONFIG_FEATURE_KILL_DELAY) {
|
---|
| 935 | /* NB: parent will wait in NOMMU case */
|
---|
| 936 | if ((BB_MMU ? fork() : vfork()) == 0) { /* child */
|
---|
| 937 | sleep(CONFIG_FEATURE_KILL_DELAY);
|
---|
| 938 | for (a = init_action_list; a; a = a->next)
|
---|
| 939 | if (a->action_type == 0 && a->pid != 0)
|
---|
| 940 | kill(a->pid, SIGKILL);
|
---|
| 941 | _exit(EXIT_SUCCESS);
|
---|
[821] | 942 | }
|
---|
[2725] | 943 | }
|
---|
| 944 | #endif
|
---|
[821] | 945 |
|
---|
[2725] | 946 | /* Remove stale entries and SYSINIT entries.
|
---|
| 947 | * We never rerun SYSINIT entries anyway,
|
---|
[3621] | 948 | * removing them too saves a few bytes
|
---|
| 949 | */
|
---|
[2725] | 950 | nextp = &init_action_list;
|
---|
| 951 | while ((a = *nextp) != NULL) {
|
---|
[3621] | 952 | /*
|
---|
| 953 | * Why pid == 0 check?
|
---|
| 954 | * Process can be removed from inittab and added *later*.
|
---|
| 955 | * If we delete its entry but process still runs,
|
---|
| 956 | * duplicate is spawned when the entry is re-added.
|
---|
| 957 | */
|
---|
| 958 | if ((a->action_type & ~SYSINIT) == 0 && a->pid == 0) {
|
---|
[2725] | 959 | *nextp = a->next;
|
---|
| 960 | free(a);
|
---|
[821] | 961 | } else {
|
---|
[2725] | 962 | nextp = &a->next;
|
---|
[821] | 963 | }
|
---|
[2725] | 964 | }
|
---|
[821] | 965 |
|
---|
[2725] | 966 | /* Not needed: */
|
---|
| 967 | /* run_actions(RESPAWN | ASKFIRST); */
|
---|
| 968 | /* - we return to main loop, which does this automagically */
|
---|
[821] | 969 | }
|
---|
[2725] | 970 | #endif
|
---|
[821] | 971 |
|
---|
[2725] | 972 | static int check_delayed_sigs(void)
|
---|
[821] | 973 | {
|
---|
[2725] | 974 | int sigs_seen = 0;
|
---|
[821] | 975 |
|
---|
[2725] | 976 | while (1) {
|
---|
| 977 | smallint sig = bb_got_signal;
|
---|
[821] | 978 |
|
---|
[2725] | 979 | if (!sig)
|
---|
| 980 | return sigs_seen;
|
---|
| 981 | bb_got_signal = 0;
|
---|
| 982 | sigs_seen = 1;
|
---|
| 983 | #if ENABLE_FEATURE_USE_INITTAB
|
---|
| 984 | if (sig == SIGHUP)
|
---|
| 985 | reload_inittab();
|
---|
| 986 | #endif
|
---|
| 987 | if (sig == SIGINT)
|
---|
| 988 | run_actions(CTRLALTDEL);
|
---|
[3621] | 989 | if (sig == SIGQUIT) {
|
---|
| 990 | exec_restart_action();
|
---|
| 991 | /* returns only if no restart action defined */
|
---|
| 992 | }
|
---|
| 993 | if ((1 << sig) & (0
|
---|
| 994 | #ifdef SIGPWR
|
---|
| 995 | + (1 << SIGPWR)
|
---|
| 996 | #endif
|
---|
| 997 | + (1 << SIGUSR1)
|
---|
| 998 | + (1 << SIGUSR2)
|
---|
| 999 | + (1 << SIGTERM)
|
---|
| 1000 | )) {
|
---|
| 1001 | halt_reboot_pwoff(sig);
|
---|
| 1002 | }
|
---|
[821] | 1003 | }
|
---|
| 1004 | }
|
---|
| 1005 |
|
---|
[3232] | 1006 | #if DEBUG_SEGV_HANDLER
|
---|
| 1007 | static
|
---|
| 1008 | void handle_sigsegv(int sig, siginfo_t *info, void *ucontext)
|
---|
| 1009 | {
|
---|
| 1010 | long ip;
|
---|
| 1011 | ucontext_t *uc;
|
---|
| 1012 |
|
---|
| 1013 | uc = ucontext;
|
---|
| 1014 | ip = uc->uc_mcontext.gregs[REG_EIP];
|
---|
| 1015 | fdprintf(2, "signal:%d address:0x%lx ip:0x%lx\n",
|
---|
| 1016 | sig,
|
---|
| 1017 | /* this is void*, but using %p would print "(null)"
|
---|
| 1018 | * even for ptrs which are not exactly 0, but, say, 0x123:
|
---|
| 1019 | */
|
---|
| 1020 | (long)info->si_addr,
|
---|
| 1021 | ip);
|
---|
| 1022 | {
|
---|
| 1023 | /* glibc extension */
|
---|
| 1024 | void *array[50];
|
---|
| 1025 | int size;
|
---|
| 1026 | size = backtrace(array, 50);
|
---|
| 1027 | backtrace_symbols_fd(array, size, 2);
|
---|
| 1028 | }
|
---|
| 1029 | for (;;) sleep(9999);
|
---|
| 1030 | }
|
---|
| 1031 | #endif
|
---|
| 1032 |
|
---|
[3621] | 1033 | static void sleep_much(void)
|
---|
| 1034 | {
|
---|
| 1035 | sleep(30 * 24*60*60);
|
---|
| 1036 | }
|
---|
| 1037 |
|
---|
[2725] | 1038 | int init_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
| 1039 | int init_main(int argc UNUSED_PARAM, char **argv)
|
---|
[821] | 1040 | {
|
---|
[2725] | 1041 | if (argv[1] && strcmp(argv[1], "-q") == 0) {
|
---|
[1765] | 1042 | return kill(1, SIGHUP);
|
---|
[821] | 1043 | }
|
---|
| 1044 |
|
---|
[3232] | 1045 | #if DEBUG_SEGV_HANDLER
|
---|
| 1046 | {
|
---|
| 1047 | struct sigaction sa;
|
---|
| 1048 | memset(&sa, 0, sizeof(sa));
|
---|
| 1049 | sa.sa_sigaction = handle_sigsegv;
|
---|
| 1050 | sa.sa_flags = SA_SIGINFO;
|
---|
| 1051 | sigaction(SIGSEGV, &sa, NULL);
|
---|
| 1052 | sigaction(SIGILL, &sa, NULL);
|
---|
| 1053 | sigaction(SIGFPE, &sa, NULL);
|
---|
| 1054 | sigaction(SIGBUS, &sa, NULL);
|
---|
| 1055 | }
|
---|
| 1056 | #endif
|
---|
| 1057 |
|
---|
[2725] | 1058 | if (!DEBUG_INIT) {
|
---|
| 1059 | /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
|
---|
| 1060 | if (getpid() != 1
|
---|
[3621] | 1061 | && (!ENABLE_LINUXRC || applet_name[0] != 'l') /* not linuxrc? */
|
---|
[2725] | 1062 | ) {
|
---|
| 1063 | bb_error_msg_and_die("must be run as PID 1");
|
---|
| 1064 | }
|
---|
| 1065 | #ifdef RB_DISABLE_CAD
|
---|
| 1066 | /* Turn off rebooting via CTL-ALT-DEL - we get a
|
---|
| 1067 | * SIGINT on CAD so we can shut things down gracefully... */
|
---|
| 1068 | reboot(RB_DISABLE_CAD); /* misnomer */
|
---|
[821] | 1069 | #endif
|
---|
[2725] | 1070 | }
|
---|
[821] | 1071 |
|
---|
[2725] | 1072 | /* If, say, xmalloc would ever die, we don't want to oops kernel
|
---|
| 1073 | * by exiting.
|
---|
[3621] | 1074 | * NB: we set die_func *after* PID 1 check and bb_show_usage.
|
---|
[2725] | 1075 | * Otherwise, for example, "init u" ("please rexec yourself"
|
---|
| 1076 | * command for sysvinit) will show help text (which isn't too bad),
|
---|
| 1077 | * *and sleep forever* (which is bad!)
|
---|
| 1078 | */
|
---|
[3621] | 1079 | die_func = sleep_much;
|
---|
[1765] | 1080 |
|
---|
[821] | 1081 | /* Figure out where the default console should be */
|
---|
| 1082 | console_init();
|
---|
[1765] | 1083 | set_sane_term();
|
---|
[2725] | 1084 | xchdir("/");
|
---|
[821] | 1085 | setsid();
|
---|
[1765] | 1086 |
|
---|
[2725] | 1087 | /* Make sure environs is set to something sane */
|
---|
| 1088 | putenv((char *) "HOME=/");
|
---|
| 1089 | putenv((char *) bb_PATH_root_path);
|
---|
| 1090 | putenv((char *) "SHELL=/bin/sh");
|
---|
| 1091 | putenv((char *) "USER=root"); /* needed? why? */
|
---|
[1765] | 1092 |
|
---|
[2725] | 1093 | if (argv[1])
|
---|
| 1094 | xsetenv("RUNLEVEL", argv[1]);
|
---|
| 1095 |
|
---|
| 1096 | #if !ENABLE_FEATURE_EXTRA_QUIET
|
---|
[821] | 1097 | /* Hello world */
|
---|
[2725] | 1098 | message(L_CONSOLE | L_LOG, "init started: %s", bb_banner);
|
---|
| 1099 | #endif
|
---|
[821] | 1100 |
|
---|
[3621] | 1101 | #if 0
|
---|
| 1102 | /* It's 2013, does anyone really still depend on this? */
|
---|
| 1103 | /* If you do, consider adding swapon to sysinit actions then! */
|
---|
[2725] | 1104 | /* struct sysinfo is linux-specific */
|
---|
[3621] | 1105 | # ifdef __linux__
|
---|
[821] | 1106 | /* Make sure there is enough memory to do something useful. */
|
---|
[3621] | 1107 | /*if (ENABLE_SWAPONOFF) - WRONG: we may have non-bbox swapon*/ {
|
---|
[821] | 1108 | struct sysinfo info;
|
---|
| 1109 |
|
---|
[2725] | 1110 | if (sysinfo(&info) == 0
|
---|
| 1111 | && (info.mem_unit ? info.mem_unit : 1) * (long long)info.totalram < 1024*1024
|
---|
| 1112 | ) {
|
---|
[1765] | 1113 | message(L_CONSOLE, "Low memory, forcing swapon");
|
---|
[821] | 1114 | /* swapon -a requires /proc typically */
|
---|
[1765] | 1115 | new_init_action(SYSINIT, "mount -t proc proc /proc", "");
|
---|
[821] | 1116 | /* Try to turn on swap */
|
---|
[1765] | 1117 | new_init_action(SYSINIT, "swapon -a", "");
|
---|
[821] | 1118 | run_actions(SYSINIT); /* wait and removing */
|
---|
| 1119 | }
|
---|
| 1120 | }
|
---|
[3621] | 1121 | # endif
|
---|
[2725] | 1122 | #endif
|
---|
[821] | 1123 |
|
---|
| 1124 | /* Check if we are supposed to be in single user mode */
|
---|
[2725] | 1125 | if (argv[1]
|
---|
| 1126 | && (strcmp(argv[1], "single") == 0 || strcmp(argv[1], "-s") == 0 || LONE_CHAR(argv[1], '1'))
|
---|
[1765] | 1127 | ) {
|
---|
[2725] | 1128 | /* ??? shouldn't we set RUNLEVEL="b" here? */
|
---|
[821] | 1129 | /* Start a shell on console */
|
---|
| 1130 | new_init_action(RESPAWN, bb_default_login_shell, "");
|
---|
| 1131 | } else {
|
---|
[2725] | 1132 | /* Not in single user mode - see what inittab says */
|
---|
[821] | 1133 |
|
---|
| 1134 | /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
|
---|
| 1135 | * then parse_inittab() simply adds in some default
|
---|
[3621] | 1136 | * actions (i.e., INIT_SCRIPT and a pair
|
---|
| 1137 | * of "askfirst" shells) */
|
---|
[821] | 1138 | parse_inittab();
|
---|
| 1139 | }
|
---|
| 1140 |
|
---|
[1765] | 1141 | #if ENABLE_SELINUX
|
---|
[821] | 1142 | if (getenv("SELINUX_INIT") == NULL) {
|
---|
| 1143 | int enforce = 0;
|
---|
| 1144 |
|
---|
[1765] | 1145 | putenv((char*)"SELINUX_INIT=YES");
|
---|
[821] | 1146 | if (selinux_init_load_policy(&enforce) == 0) {
|
---|
[1765] | 1147 | BB_EXECVP(argv[0], argv);
|
---|
[821] | 1148 | } else if (enforce > 0) {
|
---|
| 1149 | /* SELinux in enforcing mode but load_policy failed */
|
---|
[2725] | 1150 | message(L_CONSOLE, "can't load SELinux Policy. "
|
---|
[1765] | 1151 | "Machine is in enforcing mode. Halting now.");
|
---|
[2725] | 1152 | return EXIT_FAILURE;
|
---|
[821] | 1153 | }
|
---|
| 1154 | }
|
---|
[2725] | 1155 | #endif
|
---|
[821] | 1156 |
|
---|
[3621] | 1157 | if (ENABLE_FEATURE_INIT_MODIFY_CMDLINE) {
|
---|
| 1158 | /* Make the command line just say "init" - that's all, nothing else */
|
---|
| 1159 | strncpy(argv[0], "init", strlen(argv[0]));
|
---|
| 1160 | /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
|
---|
| 1161 | while (*++argv)
|
---|
| 1162 | nuke_str(*argv);
|
---|
| 1163 | }
|
---|
[821] | 1164 |
|
---|
[2725] | 1165 | /* Set up signal handlers */
|
---|
| 1166 | if (!DEBUG_INIT) {
|
---|
| 1167 | struct sigaction sa;
|
---|
| 1168 |
|
---|
| 1169 | /* Stop handler must allow only SIGCONT inside itself */
|
---|
| 1170 | memset(&sa, 0, sizeof(sa));
|
---|
| 1171 | sigfillset(&sa.sa_mask);
|
---|
| 1172 | sigdelset(&sa.sa_mask, SIGCONT);
|
---|
| 1173 | sa.sa_handler = stop_handler;
|
---|
| 1174 | /* NB: sa_flags doesn't have SA_RESTART.
|
---|
| 1175 | * It must be able to interrupt wait().
|
---|
| 1176 | */
|
---|
| 1177 | sigaction_set(SIGTSTP, &sa); /* pause */
|
---|
| 1178 | /* Does not work as intended, at least in 2.6.20.
|
---|
| 1179 | * SIGSTOP is simply ignored by init:
|
---|
| 1180 | */
|
---|
| 1181 | sigaction_set(SIGSTOP, &sa); /* pause */
|
---|
| 1182 |
|
---|
[3621] | 1183 | /* These signals must interrupt wait(),
|
---|
[2725] | 1184 | * setting handler without SA_RESTART flag.
|
---|
| 1185 | */
|
---|
[3621] | 1186 | bb_signals_recursive_norestart(0
|
---|
| 1187 | + (1 << SIGINT) /* Ctrl-Alt-Del */
|
---|
| 1188 | + (1 << SIGQUIT) /* re-exec another init */
|
---|
| 1189 | #ifdef SIGPWR
|
---|
| 1190 | + (1 << SIGPWR) /* halt */
|
---|
| 1191 | #endif
|
---|
| 1192 | + (1 << SIGUSR1) /* halt */
|
---|
| 1193 | + (1 << SIGTERM) /* reboot */
|
---|
| 1194 | + (1 << SIGUSR2) /* poweroff */
|
---|
| 1195 | #if ENABLE_FEATURE_USE_INITTAB
|
---|
| 1196 | + (1 << SIGHUP) /* reread /etc/inittab */
|
---|
| 1197 | #endif
|
---|
| 1198 | , record_signo);
|
---|
[2725] | 1199 | }
|
---|
| 1200 |
|
---|
[821] | 1201 | /* Now run everything that needs to be run */
|
---|
| 1202 | /* First run the sysinit command */
|
---|
| 1203 | run_actions(SYSINIT);
|
---|
[2725] | 1204 | check_delayed_sigs();
|
---|
[821] | 1205 | /* Next run anything that wants to block */
|
---|
| 1206 | run_actions(WAIT);
|
---|
[2725] | 1207 | check_delayed_sigs();
|
---|
[821] | 1208 | /* Next run anything to be run only once */
|
---|
| 1209 | run_actions(ONCE);
|
---|
| 1210 |
|
---|
[2725] | 1211 | /* Now run the looping stuff for the rest of forever.
|
---|
| 1212 | */
|
---|
[821] | 1213 | while (1) {
|
---|
[2725] | 1214 | int maybe_WNOHANG;
|
---|
[821] | 1215 |
|
---|
[2725] | 1216 | maybe_WNOHANG = check_delayed_sigs();
|
---|
[821] | 1217 |
|
---|
[2725] | 1218 | /* (Re)run the respawn/askfirst stuff */
|
---|
| 1219 | run_actions(RESPAWN | ASKFIRST);
|
---|
| 1220 | maybe_WNOHANG |= check_delayed_sigs();
|
---|
| 1221 |
|
---|
| 1222 | /* Don't consume all CPU time - sleep a bit */
|
---|
[821] | 1223 | sleep(1);
|
---|
[2725] | 1224 | maybe_WNOHANG |= check_delayed_sigs();
|
---|
[821] | 1225 |
|
---|
[2725] | 1226 | /* Wait for any child process(es) to exit.
|
---|
| 1227 | *
|
---|
| 1228 | * If check_delayed_sigs above reported that a signal
|
---|
| 1229 | * was caught, wait will be nonblocking. This ensures
|
---|
| 1230 | * that if SIGHUP has reloaded inittab, respawn and askfirst
|
---|
| 1231 | * actions will not be delayed until next child death.
|
---|
| 1232 | */
|
---|
| 1233 | if (maybe_WNOHANG)
|
---|
| 1234 | maybe_WNOHANG = WNOHANG;
|
---|
| 1235 | while (1) {
|
---|
| 1236 | pid_t wpid;
|
---|
| 1237 | struct init_action *a;
|
---|
| 1238 |
|
---|
| 1239 | /* If signals happen _in_ the wait, they interrupt it,
|
---|
| 1240 | * bb_signals_recursive_norestart set them up that way
|
---|
| 1241 | */
|
---|
| 1242 | wpid = waitpid(-1, NULL, maybe_WNOHANG);
|
---|
| 1243 | if (wpid <= 0)
|
---|
| 1244 | break;
|
---|
| 1245 |
|
---|
| 1246 | a = mark_terminated(wpid);
|
---|
| 1247 | if (a) {
|
---|
| 1248 | message(L_LOG, "process '%s' (pid %d) exited. "
|
---|
| 1249 | "Scheduling for restart.",
|
---|
| 1250 | a->command, wpid);
|
---|
[821] | 1251 | }
|
---|
[2725] | 1252 | /* See if anyone else is waiting to be reaped */
|
---|
| 1253 | maybe_WNOHANG = WNOHANG;
|
---|
[821] | 1254 | }
|
---|
[2725] | 1255 | } /* while (1) */
|
---|
[821] | 1256 | }
|
---|
[2725] | 1257 |
|
---|
| 1258 | //usage:#define linuxrc_trivial_usage NOUSAGE_STR
|
---|
| 1259 | //usage:#define linuxrc_full_usage ""
|
---|
| 1260 |
|
---|
| 1261 | //usage:#define init_trivial_usage
|
---|
| 1262 | //usage: ""
|
---|
| 1263 | //usage:#define init_full_usage "\n\n"
|
---|
[3621] | 1264 | //usage: "Init is the first process started during boot. It never exits."
|
---|
| 1265 | //usage: IF_FEATURE_USE_INITTAB(
|
---|
| 1266 | //usage: "\n""It (re)spawns children according to /etc/inittab."
|
---|
| 1267 | //usage: )
|
---|
| 1268 | //usage: IF_NOT_FEATURE_USE_INITTAB(
|
---|
| 1269 | //usage: "\n""This version of init doesn't use /etc/inittab,"
|
---|
| 1270 | //usage: "\n""has fixed set of processed to run."
|
---|
| 1271 | //usage: )
|
---|
[2725] | 1272 | //usage:
|
---|
| 1273 | //usage:#define init_notes_usage
|
---|
| 1274 | //usage: "This version of init is designed to be run only by the kernel.\n"
|
---|
| 1275 | //usage: "\n"
|
---|
| 1276 | //usage: "BusyBox init doesn't support multiple runlevels. The runlevels field of\n"
|
---|
| 1277 | //usage: "the /etc/inittab file is completely ignored by BusyBox init. If you want\n"
|
---|
| 1278 | //usage: "runlevels, use sysvinit.\n"
|
---|
| 1279 | //usage: "\n"
|
---|
| 1280 | //usage: "BusyBox init works just fine without an inittab. If no inittab is found,\n"
|
---|
| 1281 | //usage: "it has the following default behavior:\n"
|
---|
| 1282 | //usage: "\n"
|
---|
| 1283 | //usage: " ::sysinit:/etc/init.d/rcS\n"
|
---|
| 1284 | //usage: " ::askfirst:/bin/sh\n"
|
---|
| 1285 | //usage: " ::ctrlaltdel:/sbin/reboot\n"
|
---|
| 1286 | //usage: " ::shutdown:/sbin/swapoff -a\n"
|
---|
| 1287 | //usage: " ::shutdown:/bin/umount -a -r\n"
|
---|
| 1288 | //usage: " ::restart:/sbin/init\n"
|
---|
| 1289 | //usage: " tty2::askfirst:/bin/sh\n"
|
---|
| 1290 | //usage: " tty3::askfirst:/bin/sh\n"
|
---|
| 1291 | //usage: " tty4::askfirst:/bin/sh\n"
|
---|
| 1292 | //usage: "\n"
|
---|
| 1293 | //usage: "If you choose to use an /etc/inittab file, the inittab entry format is as follows:\n"
|
---|
| 1294 | //usage: "\n"
|
---|
| 1295 | //usage: " <id>:<runlevels>:<action>:<process>\n"
|
---|
| 1296 | //usage: "\n"
|
---|
| 1297 | //usage: " <id>:\n"
|
---|
| 1298 | //usage: "\n"
|
---|
| 1299 | //usage: " WARNING: This field has a non-traditional meaning for BusyBox init!\n"
|
---|
| 1300 | //usage: " The id field is used by BusyBox init to specify the controlling tty for\n"
|
---|
| 1301 | //usage: " the specified process to run on. The contents of this field are\n"
|
---|
| 1302 | //usage: " appended to \"/dev/\" and used as-is. There is no need for this field to\n"
|
---|
| 1303 | //usage: " be unique, although if it isn't you may have strange results. If this\n"
|
---|
[3621] | 1304 | //usage: " field is left blank, then the init's stdin/out will be used.\n"
|
---|
[2725] | 1305 | //usage: "\n"
|
---|
| 1306 | //usage: " <runlevels>:\n"
|
---|
| 1307 | //usage: "\n"
|
---|
| 1308 | //usage: " The runlevels field is completely ignored.\n"
|
---|
| 1309 | //usage: "\n"
|
---|
| 1310 | //usage: " <action>:\n"
|
---|
| 1311 | //usage: "\n"
|
---|
| 1312 | //usage: " Valid actions include: sysinit, respawn, askfirst, wait,\n"
|
---|
| 1313 | //usage: " once, restart, ctrlaltdel, and shutdown.\n"
|
---|
| 1314 | //usage: "\n"
|
---|
| 1315 | //usage: " The available actions can be classified into two groups: actions\n"
|
---|
| 1316 | //usage: " that are run only once, and actions that are re-run when the specified\n"
|
---|
| 1317 | //usage: " process exits.\n"
|
---|
| 1318 | //usage: "\n"
|
---|
| 1319 | //usage: " Run only-once actions:\n"
|
---|
| 1320 | //usage: "\n"
|
---|
| 1321 | //usage: " 'sysinit' is the first item run on boot. init waits until all\n"
|
---|
| 1322 | //usage: " sysinit actions are completed before continuing. Following the\n"
|
---|
| 1323 | //usage: " completion of all sysinit actions, all 'wait' actions are run.\n"
|
---|
| 1324 | //usage: " 'wait' actions, like 'sysinit' actions, cause init to wait until\n"
|
---|
| 1325 | //usage: " the specified task completes. 'once' actions are asynchronous,\n"
|
---|
| 1326 | //usage: " therefore, init does not wait for them to complete. 'restart' is\n"
|
---|
| 1327 | //usage: " the action taken to restart the init process. By default this should\n"
|
---|
| 1328 | //usage: " simply run /sbin/init, but can be a script which runs pivot_root or it\n"
|
---|
| 1329 | //usage: " can do all sorts of other interesting things. The 'ctrlaltdel' init\n"
|
---|
| 1330 | //usage: " actions are run when the system detects that someone on the system\n"
|
---|
| 1331 | //usage: " console has pressed the CTRL-ALT-DEL key combination. Typically one\n"
|
---|
| 1332 | //usage: " wants to run 'reboot' at this point to cause the system to reboot.\n"
|
---|
| 1333 | //usage: " Finally the 'shutdown' action specifies the actions to taken when\n"
|
---|
| 1334 | //usage: " init is told to reboot. Unmounting filesystems and disabling swap\n"
|
---|
| 1335 | //usage: " is a very good here.\n"
|
---|
| 1336 | //usage: "\n"
|
---|
| 1337 | //usage: " Run repeatedly actions:\n"
|
---|
| 1338 | //usage: "\n"
|
---|
| 1339 | //usage: " 'respawn' actions are run after the 'once' actions. When a process\n"
|
---|
| 1340 | //usage: " started with a 'respawn' action exits, init automatically restarts\n"
|
---|
| 1341 | //usage: " it. Unlike sysvinit, BusyBox init does not stop processes from\n"
|
---|
| 1342 | //usage: " respawning out of control. The 'askfirst' actions acts just like\n"
|
---|
| 1343 | //usage: " respawn, except that before running the specified process it\n"
|
---|
| 1344 | //usage: " displays the line \"Please press Enter to activate this console.\"\n"
|
---|
| 1345 | //usage: " and then waits for the user to press enter before starting the\n"
|
---|
| 1346 | //usage: " specified process.\n"
|
---|
| 1347 | //usage: "\n"
|
---|
| 1348 | //usage: " Unrecognized actions (like initdefault) will cause init to emit an\n"
|
---|
| 1349 | //usage: " error message, and then go along with its business. All actions are\n"
|
---|
| 1350 | //usage: " run in the order they appear in /etc/inittab.\n"
|
---|
| 1351 | //usage: "\n"
|
---|
| 1352 | //usage: " <process>:\n"
|
---|
| 1353 | //usage: "\n"
|
---|
| 1354 | //usage: " Specifies the process to be executed and its command line.\n"
|
---|
| 1355 | //usage: "\n"
|
---|
| 1356 | //usage: "Example /etc/inittab file:\n"
|
---|
| 1357 | //usage: "\n"
|
---|
| 1358 | //usage: " # This is run first except when booting in single-user mode\n"
|
---|
| 1359 | //usage: " #\n"
|
---|
| 1360 | //usage: " ::sysinit:/etc/init.d/rcS\n"
|
---|
| 1361 | //usage: " \n"
|
---|
| 1362 | //usage: " # /bin/sh invocations on selected ttys\n"
|
---|
| 1363 | //usage: " #\n"
|
---|
| 1364 | //usage: " # Start an \"askfirst\" shell on the console (whatever that may be)\n"
|
---|
| 1365 | //usage: " ::askfirst:-/bin/sh\n"
|
---|
| 1366 | //usage: " # Start an \"askfirst\" shell on /dev/tty2-4\n"
|
---|
| 1367 | //usage: " tty2::askfirst:-/bin/sh\n"
|
---|
| 1368 | //usage: " tty3::askfirst:-/bin/sh\n"
|
---|
| 1369 | //usage: " tty4::askfirst:-/bin/sh\n"
|
---|
| 1370 | //usage: " \n"
|
---|
| 1371 | //usage: " # /sbin/getty invocations for selected ttys\n"
|
---|
| 1372 | //usage: " #\n"
|
---|
| 1373 | //usage: " tty4::respawn:/sbin/getty 38400 tty4\n"
|
---|
| 1374 | //usage: " tty5::respawn:/sbin/getty 38400 tty5\n"
|
---|
| 1375 | //usage: " \n"
|
---|
| 1376 | //usage: " \n"
|
---|
| 1377 | //usage: " # Example of how to put a getty on a serial line (for a terminal)\n"
|
---|
| 1378 | //usage: " #\n"
|
---|
| 1379 | //usage: " #::respawn:/sbin/getty -L ttyS0 9600 vt100\n"
|
---|
| 1380 | //usage: " #::respawn:/sbin/getty -L ttyS1 9600 vt100\n"
|
---|
| 1381 | //usage: " #\n"
|
---|
| 1382 | //usage: " # Example how to put a getty on a modem line\n"
|
---|
| 1383 | //usage: " #::respawn:/sbin/getty 57600 ttyS2\n"
|
---|
| 1384 | //usage: " \n"
|
---|
| 1385 | //usage: " # Stuff to do when restarting the init process\n"
|
---|
| 1386 | //usage: " ::restart:/sbin/init\n"
|
---|
| 1387 | //usage: " \n"
|
---|
| 1388 | //usage: " # Stuff to do before rebooting\n"
|
---|
| 1389 | //usage: " ::ctrlaltdel:/sbin/reboot\n"
|
---|
| 1390 | //usage: " ::shutdown:/bin/umount -a -r\n"
|
---|
| 1391 | //usage: " ::shutdown:/sbin/swapoff -a\n"
|
---|