From db5fe62b6d9977304b864f961dae71232091b26c Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 2 Nov 2010 20:13:03 +0100 Subject: init: if PID!=1, show clearer error message. move usage text closer to main() Signed-off-by: Denys Vlasenko --- init/init.c | 271 ++++++++++++++++++++++++++++++------------------------------ 1 file changed, 137 insertions(+), 134 deletions(-) (limited to 'init/init.c') diff --git a/init/init.c b/init/init.c index a7bbd5e64..0a0d503b5 100644 --- a/init/init.c +++ b/init/init.c @@ -108,138 +108,6 @@ //config: Note that on Linux, init attempts to detect serial terminal and //config: sets TERM to "vt102" if one is found. -//usage:#define init_trivial_usage -//usage: "" -//usage:#define init_full_usage "\n\n" -//usage: "Init is the parent of all processes" -//usage: -//usage:#define init_notes_usage -//usage: "This version of init is designed to be run only by the kernel.\n" -//usage: "\n" -//usage: "BusyBox init doesn't support multiple runlevels. The runlevels field of\n" -//usage: "the /etc/inittab file is completely ignored by BusyBox init. If you want\n" -//usage: "runlevels, use sysvinit.\n" -//usage: "\n" -//usage: "BusyBox init works just fine without an inittab. If no inittab is found,\n" -//usage: "it has the following default behavior:\n" -//usage: "\n" -//usage: " ::sysinit:/etc/init.d/rcS\n" -//usage: " ::askfirst:/bin/sh\n" -//usage: " ::ctrlaltdel:/sbin/reboot\n" -//usage: " ::shutdown:/sbin/swapoff -a\n" -//usage: " ::shutdown:/bin/umount -a -r\n" -//usage: " ::restart:/sbin/init\n" -//usage: "\n" -//usage: "if it detects that /dev/console is _not_ a serial console, it will also run:\n" -//usage: "\n" -//usage: " tty2::askfirst:/bin/sh\n" -//usage: " tty3::askfirst:/bin/sh\n" -//usage: " tty4::askfirst:/bin/sh\n" -//usage: "\n" -//usage: "If you choose to use an /etc/inittab file, the inittab entry format is as follows:\n" -//usage: "\n" -//usage: " :::\n" -//usage: "\n" -//usage: " :\n" -//usage: "\n" -//usage: " WARNING: This field has a non-traditional meaning for BusyBox init!\n" -//usage: " The id field is used by BusyBox init to specify the controlling tty for\n" -//usage: " the specified process to run on. The contents of this field are\n" -//usage: " appended to \"/dev/\" and used as-is. There is no need for this field to\n" -//usage: " be unique, although if it isn't you may have strange results. If this\n" -//usage: " field is left blank, the controlling tty is set to the console. Also\n" -//usage: " note that if BusyBox detects that a serial console is in use, then only\n" -//usage: " entries whose controlling tty is either the serial console or /dev/null\n" -//usage: " will be run. BusyBox init does nothing with utmp. We don't need no\n" -//usage: " stinkin' utmp.\n" -//usage: "\n" -//usage: " :\n" -//usage: "\n" -//usage: " The runlevels field is completely ignored.\n" -//usage: "\n" -//usage: " :\n" -//usage: "\n" -//usage: " Valid actions include: sysinit, respawn, askfirst, wait,\n" -//usage: " once, restart, ctrlaltdel, and shutdown.\n" -//usage: "\n" -//usage: " The available actions can be classified into two groups: actions\n" -//usage: " that are run only once, and actions that are re-run when the specified\n" -//usage: " process exits.\n" -//usage: "\n" -//usage: " Run only-once actions:\n" -//usage: "\n" -//usage: " 'sysinit' is the first item run on boot. init waits until all\n" -//usage: " sysinit actions are completed before continuing. Following the\n" -//usage: " completion of all sysinit actions, all 'wait' actions are run.\n" -//usage: " 'wait' actions, like 'sysinit' actions, cause init to wait until\n" -//usage: " the specified task completes. 'once' actions are asynchronous,\n" -//usage: " therefore, init does not wait for them to complete. 'restart' is\n" -//usage: " the action taken to restart the init process. By default this should\n" -//usage: " simply run /sbin/init, but can be a script which runs pivot_root or it\n" -//usage: " can do all sorts of other interesting things. The 'ctrlaltdel' init\n" -//usage: " actions are run when the system detects that someone on the system\n" -//usage: " console has pressed the CTRL-ALT-DEL key combination. Typically one\n" -//usage: " wants to run 'reboot' at this point to cause the system to reboot.\n" -//usage: " Finally the 'shutdown' action specifies the actions to taken when\n" -//usage: " init is told to reboot. Unmounting filesystems and disabling swap\n" -//usage: " is a very good here.\n" -//usage: "\n" -//usage: " Run repeatedly actions:\n" -//usage: "\n" -//usage: " 'respawn' actions are run after the 'once' actions. When a process\n" -//usage: " started with a 'respawn' action exits, init automatically restarts\n" -//usage: " it. Unlike sysvinit, BusyBox init does not stop processes from\n" -//usage: " respawning out of control. The 'askfirst' actions acts just like\n" -//usage: " respawn, except that before running the specified process it\n" -//usage: " displays the line \"Please press Enter to activate this console.\"\n" -//usage: " and then waits for the user to press enter before starting the\n" -//usage: " specified process.\n" -//usage: "\n" -//usage: " Unrecognized actions (like initdefault) will cause init to emit an\n" -//usage: " error message, and then go along with its business. All actions are\n" -//usage: " run in the order they appear in /etc/inittab.\n" -//usage: "\n" -//usage: " :\n" -//usage: "\n" -//usage: " Specifies the process to be executed and its command line.\n" -//usage: "\n" -//usage: "Example /etc/inittab file:\n" -//usage: "\n" -//usage: " # This is run first except when booting in single-user mode\n" -//usage: " #\n" -//usage: " ::sysinit:/etc/init.d/rcS\n" -//usage: " \n" -//usage: " # /bin/sh invocations on selected ttys\n" -//usage: " #\n" -//usage: " # Start an \"askfirst\" shell on the console (whatever that may be)\n" -//usage: " ::askfirst:-/bin/sh\n" -//usage: " # Start an \"askfirst\" shell on /dev/tty2-4\n" -//usage: " tty2::askfirst:-/bin/sh\n" -//usage: " tty3::askfirst:-/bin/sh\n" -//usage: " tty4::askfirst:-/bin/sh\n" -//usage: " \n" -//usage: " # /sbin/getty invocations for selected ttys\n" -//usage: " #\n" -//usage: " tty4::respawn:/sbin/getty 38400 tty4\n" -//usage: " tty5::respawn:/sbin/getty 38400 tty5\n" -//usage: " \n" -//usage: " \n" -//usage: " # Example of how to put a getty on a serial line (for a terminal)\n" -//usage: " #\n" -//usage: " #::respawn:/sbin/getty -L ttyS0 9600 vt100\n" -//usage: " #::respawn:/sbin/getty -L ttyS1 9600 vt100\n" -//usage: " #\n" -//usage: " # Example how to put a getty on a modem line\n" -//usage: " #::respawn:/sbin/getty 57600 ttyS2\n" -//usage: " \n" -//usage: " # Stuff to do when restarting the init process\n" -//usage: " ::restart:/sbin/init\n" -//usage: " \n" -//usage: " # Stuff to do before rebooting\n" -//usage: " ::ctrlaltdel:/sbin/reboot\n" -//usage: " ::shutdown:/bin/umount -a -r\n" -//usage: " ::shutdown:/sbin/swapoff -a\n" - #include "libbb.h" #include #include @@ -1095,9 +963,9 @@ int init_main(int argc UNUSED_PARAM, char **argv) if (!DEBUG_INIT) { /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */ if (getpid() != 1 - && (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc")) + && (!ENABLE_FEATURE_INITRD || applet_name[0] != 'l') /* not linuxrc? */ ) { - bb_show_usage(); + bb_error_msg_and_die("must be run as PID 1"); } #ifdef RB_DISABLE_CAD /* Turn off rebooting via CTL-ALT-DEL - we get a @@ -1286,3 +1154,138 @@ int init_main(int argc UNUSED_PARAM, char **argv) } } /* while (1) */ } + +//usage:#define linuxrc_trivial_usage NOUSAGE_STR +//usage:#define linuxrc_full_usage "" + +//usage:#define init_trivial_usage +//usage: "" +//usage:#define init_full_usage "\n\n" +//usage: "Init is the parent of all processes" +//usage: +//usage:#define init_notes_usage +//usage: "This version of init is designed to be run only by the kernel.\n" +//usage: "\n" +//usage: "BusyBox init doesn't support multiple runlevels. The runlevels field of\n" +//usage: "the /etc/inittab file is completely ignored by BusyBox init. If you want\n" +//usage: "runlevels, use sysvinit.\n" +//usage: "\n" +//usage: "BusyBox init works just fine without an inittab. If no inittab is found,\n" +//usage: "it has the following default behavior:\n" +//usage: "\n" +//usage: " ::sysinit:/etc/init.d/rcS\n" +//usage: " ::askfirst:/bin/sh\n" +//usage: " ::ctrlaltdel:/sbin/reboot\n" +//usage: " ::shutdown:/sbin/swapoff -a\n" +//usage: " ::shutdown:/bin/umount -a -r\n" +//usage: " ::restart:/sbin/init\n" +//usage: "\n" +//usage: "if it detects that /dev/console is _not_ a serial console, it will also run:\n" +//usage: "\n" +//usage: " tty2::askfirst:/bin/sh\n" +//usage: " tty3::askfirst:/bin/sh\n" +//usage: " tty4::askfirst:/bin/sh\n" +//usage: "\n" +//usage: "If you choose to use an /etc/inittab file, the inittab entry format is as follows:\n" +//usage: "\n" +//usage: " :::\n" +//usage: "\n" +//usage: " :\n" +//usage: "\n" +//usage: " WARNING: This field has a non-traditional meaning for BusyBox init!\n" +//usage: " The id field is used by BusyBox init to specify the controlling tty for\n" +//usage: " the specified process to run on. The contents of this field are\n" +//usage: " appended to \"/dev/\" and used as-is. There is no need for this field to\n" +//usage: " be unique, although if it isn't you may have strange results. If this\n" +//usage: " field is left blank, the controlling tty is set to the console. Also\n" +//usage: " note that if BusyBox detects that a serial console is in use, then only\n" +//usage: " entries whose controlling tty is either the serial console or /dev/null\n" +//usage: " will be run. BusyBox init does nothing with utmp. We don't need no\n" +//usage: " stinkin' utmp.\n" +//usage: "\n" +//usage: " :\n" +//usage: "\n" +//usage: " The runlevels field is completely ignored.\n" +//usage: "\n" +//usage: " :\n" +//usage: "\n" +//usage: " Valid actions include: sysinit, respawn, askfirst, wait,\n" +//usage: " once, restart, ctrlaltdel, and shutdown.\n" +//usage: "\n" +//usage: " The available actions can be classified into two groups: actions\n" +//usage: " that are run only once, and actions that are re-run when the specified\n" +//usage: " process exits.\n" +//usage: "\n" +//usage: " Run only-once actions:\n" +//usage: "\n" +//usage: " 'sysinit' is the first item run on boot. init waits until all\n" +//usage: " sysinit actions are completed before continuing. Following the\n" +//usage: " completion of all sysinit actions, all 'wait' actions are run.\n" +//usage: " 'wait' actions, like 'sysinit' actions, cause init to wait until\n" +//usage: " the specified task completes. 'once' actions are asynchronous,\n" +//usage: " therefore, init does not wait for them to complete. 'restart' is\n" +//usage: " the action taken to restart the init process. By default this should\n" +//usage: " simply run /sbin/init, but can be a script which runs pivot_root or it\n" +//usage: " can do all sorts of other interesting things. The 'ctrlaltdel' init\n" +//usage: " actions are run when the system detects that someone on the system\n" +//usage: " console has pressed the CTRL-ALT-DEL key combination. Typically one\n" +//usage: " wants to run 'reboot' at this point to cause the system to reboot.\n" +//usage: " Finally the 'shutdown' action specifies the actions to taken when\n" +//usage: " init is told to reboot. Unmounting filesystems and disabling swap\n" +//usage: " is a very good here.\n" +//usage: "\n" +//usage: " Run repeatedly actions:\n" +//usage: "\n" +//usage: " 'respawn' actions are run after the 'once' actions. When a process\n" +//usage: " started with a 'respawn' action exits, init automatically restarts\n" +//usage: " it. Unlike sysvinit, BusyBox init does not stop processes from\n" +//usage: " respawning out of control. The 'askfirst' actions acts just like\n" +//usage: " respawn, except that before running the specified process it\n" +//usage: " displays the line \"Please press Enter to activate this console.\"\n" +//usage: " and then waits for the user to press enter before starting the\n" +//usage: " specified process.\n" +//usage: "\n" +//usage: " Unrecognized actions (like initdefault) will cause init to emit an\n" +//usage: " error message, and then go along with its business. All actions are\n" +//usage: " run in the order they appear in /etc/inittab.\n" +//usage: "\n" +//usage: " :\n" +//usage: "\n" +//usage: " Specifies the process to be executed and its command line.\n" +//usage: "\n" +//usage: "Example /etc/inittab file:\n" +//usage: "\n" +//usage: " # This is run first except when booting in single-user mode\n" +//usage: " #\n" +//usage: " ::sysinit:/etc/init.d/rcS\n" +//usage: " \n" +//usage: " # /bin/sh invocations on selected ttys\n" +//usage: " #\n" +//usage: " # Start an \"askfirst\" shell on the console (whatever that may be)\n" +//usage: " ::askfirst:-/bin/sh\n" +//usage: " # Start an \"askfirst\" shell on /dev/tty2-4\n" +//usage: " tty2::askfirst:-/bin/sh\n" +//usage: " tty3::askfirst:-/bin/sh\n" +//usage: " tty4::askfirst:-/bin/sh\n" +//usage: " \n" +//usage: " # /sbin/getty invocations for selected ttys\n" +//usage: " #\n" +//usage: " tty4::respawn:/sbin/getty 38400 tty4\n" +//usage: " tty5::respawn:/sbin/getty 38400 tty5\n" +//usage: " \n" +//usage: " \n" +//usage: " # Example of how to put a getty on a serial line (for a terminal)\n" +//usage: " #\n" +//usage: " #::respawn:/sbin/getty -L ttyS0 9600 vt100\n" +//usage: " #::respawn:/sbin/getty -L ttyS1 9600 vt100\n" +//usage: " #\n" +//usage: " # Example how to put a getty on a modem line\n" +//usage: " #::respawn:/sbin/getty 57600 ttyS2\n" +//usage: " \n" +//usage: " # Stuff to do when restarting the init process\n" +//usage: " ::restart:/sbin/init\n" +//usage: " \n" +//usage: " # Stuff to do before rebooting\n" +//usage: " ::ctrlaltdel:/sbin/reboot\n" +//usage: " ::shutdown:/bin/umount -a -r\n" +//usage: " ::shutdown:/sbin/swapoff -a\n" -- cgit v1.2.3