diff options
| -rw-r--r-- | init/init.c | 172 |
1 files changed, 89 insertions, 83 deletions
diff --git a/init/init.c b/init/init.c index ed01e71..7ba8b67 100644 --- a/init/init.c +++ b/init/init.c @@ -95,18 +95,15 @@ enum { #endif }; -static void halt_reboot_pwoff(int sig) NORETURN; - /* Print a message to the specified device. * "where" may be bitwise-or'd from L_LOG | L_CONSOLE * NB: careful, we can be called after vfork! */ -#define messageD(...) do { if (DEBUG_INIT) message(__VA_ARGS__); } while (0) +#define dbg_message(...) do { if (DEBUG_INIT) message(__VA_ARGS__); } while (0) static void message(int where, const char *fmt, ...) __attribute__ ((format(printf, 2, 3))); static void message(int where, const char *fmt, ...) { - static int log_fd = -1; va_list arguments; unsigned l; char msg[128]; @@ -116,20 +113,23 @@ static void message(int where, const char *fmt, ...) l = 1 + vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments); if (l > sizeof(msg) - 1) l = sizeof(msg) - 1; - msg[l] = '\0'; va_end(arguments); - if (ENABLE_FEATURE_INIT_SYSLOG) { - if (where & L_LOG) { - /* Log the message to syslogd */ - openlog("init", 0, LOG_DAEMON); - /* don't print "\r" */ - syslog(LOG_INFO, "%s", msg + 1); - closelog(); - } - msg[l++] = '\n'; - msg[l] = '\0'; - } else { +#if ENABLE_FEATURE_INIT_SYSLOG + msg[l] = '\0'; + if (where & L_LOG) { + /* Log the message to syslogd */ + openlog("init", 0, LOG_DAEMON); + /* don't print "\r" */ + syslog(LOG_INFO, "%s", msg + 1); + closelog(); + } + msg[l++] = '\n'; + msg[l] = '\0'; +#else + { + static int log_fd = -1; + msg[l++] = '\n'; msg[l] = '\0'; /* Take full control of the log tty, and never close it. @@ -153,6 +153,7 @@ static void message(int where, const char *fmt, ...) return; /* don't print dup messages */ } } +#endif if (where & L_CONSOLE) { /* Send console messages to console so people will see them. */ @@ -199,7 +200,7 @@ static void console_init(void) dup2(fd, STDOUT_FILENO); xmove_fd(fd, STDERR_FILENO); } - messageD(L_LOG, "console='%s'", s); + dbg_message(L_LOG, "console='%s'", s); } else { /* Make sure fd 0,1,2 are not closed * (so that they won't be used by future opens) */ @@ -261,7 +262,7 @@ static void set_sane_term(void) /* Open the new terminal device. * NB: careful, we can be called after vfork! */ -static void open_stdio_to_tty(const char* tty_name, int exit_on_failure) +static int open_stdio_to_tty(const char* tty_name) { /* empty tty_name means "use init's tty", else... */ if (tty_name[0]) { @@ -273,19 +274,13 @@ static void open_stdio_to_tty(const char* tty_name, int exit_on_failure) if (fd) { message(L_LOG | L_CONSOLE, "can't open %s: %s", tty_name, strerror(errno)); - if (exit_on_failure) - _exit(EXIT_FAILURE); - if (DEBUG_INIT) - _exit(2); - /* NB: we don't reach this if we were called after vfork. - * Thus halt_reboot_pwoff() itself needs not be vfork-safe. - */ - halt_reboot_pwoff(SIGUSR1); /* halt the system */ + return 0; /* failure */ } dup2(STDIN_FILENO, STDOUT_FILENO); dup2(STDIN_FILENO, STDERR_FILENO); } set_sane_term(); + return 1; /* success */ } /* Wrapper around exec: @@ -369,7 +364,8 @@ static pid_t run(const struct init_action *a) setsid(); /* Open the new terminal device */ - open_stdio_to_tty(a->terminal, 1 /* - exit if open fails */); + if (!open_stdio_to_tty(a->terminal)) + _exit(EXIT_FAILURE); /* NB: on NOMMU we can't wait for input in child, so * "askfirst" will work the same as "respawn". */ @@ -388,7 +384,7 @@ static pid_t run(const struct init_action *a) * be allowed to start a shell or whatever an init script * specifies. */ - messageD(L_LOG, "waiting for enter to start '%s'" + dbg_message(L_LOG, "waiting for enter to start '%s'" "(pid %d, tty '%s')\n", a->command, getpid(), a->terminal); full_write(STDOUT_FILENO, press_enter, sizeof(press_enter) - 1); @@ -422,21 +418,6 @@ static pid_t run(const struct init_action *a) _exit(-1); } -static void delete_init_action(struct init_action *action) -{ - struct init_action *a, **nextp; - - nextp = &init_action_list; - while ((a = *nextp) != NULL) { - if (a == action) { - *nextp = a->next; - free(a); - break; - } - nextp = &a->next; - } -} - static struct init_action *mark_terminated(int pid) { struct init_action *a; @@ -497,36 +478,44 @@ static void new_init_action(uint8_t action_type, const char *command, const char { struct init_action *a, **nextp; -//BUG -//old: -//::shutdown:umount -a -r -//::shutdown:swapoff -a -//new: swapped: -//::shutdown:swapoff -a -//::shutdown:umount -a -r -//on SIGHUP, new one will be loaded, but order will be wrong. + /* Scenario: + * old inittab: + * ::shutdown:umount -a -r + * ::shutdown:swapoff -a + * new inittab: + * ::shutdown:swapoff -a + * ::shutdown:umount -a -r + * On reload, we must ensure entries end up in correct order. + * To achieve that, if we find a matching entry, we move it + * to the end. + */ nextp = &init_action_list; while ((a = *nextp) != NULL) { /* Don't enter action if it's already in the list, - * just overwrite existing one's type. * This prevents losing running RESPAWNs. */ if ((strcmp(a->command, command) == 0) && (strcmp(a->terminal, cons) == 0) ) { - a->action_type = action_type; - return; + /* Remove from list */ + *nextp = a->next; + /* Find the end of the list */ + while (*nextp != NULL) + nextp = &(*nextp)->next; + a->next = NULL; + break; } nextp = &a->next; } + if (!a) + a = xzalloc(sizeof(*a)); /* Append to the end of the list */ - a = xzalloc(sizeof(*a)); *nextp = a; a->action_type = action_type; safe_strncpy(a->command, command, sizeof(a->command)); safe_strncpy(a->terminal, cons, sizeof(a->terminal)); - messageD(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n", + dbg_message(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n", a->command, a->action_type, a->terminal); } @@ -603,8 +592,8 @@ static void parse_inittab(void) #endif } -static void low_level_reboot(unsigned magic) NORETURN; -static void low_level_reboot(unsigned magic) +static void pause_and_low_level_reboot(unsigned magic) NORETURN; +static void pause_and_low_level_reboot(unsigned magic) { pid_t pid; @@ -619,12 +608,11 @@ static void low_level_reboot(unsigned magic) reboot(magic); _exit(EXIT_SUCCESS); } - waitfor(pid); while (1) sleep(1); } -static void kill_all_processes(void) +static void run_shutdown_and_kill_processes(void) { /* Run everything to be run at "shutdown". This is done _prior_ * to killing everything, in case people wish to use scripts to @@ -633,19 +621,16 @@ static void kill_all_processes(void) message(L_CONSOLE | L_LOG, "The system is going down NOW!"); - /* Allow Ctrl-Alt-Del to reboot system. */ - reboot(RB_ENABLE_CAD); /* misnomer */ - /* Send signals to every process _except_ pid 1 */ - message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "TERM"); kill(-1, SIGTERM); + message(L_CONSOLE | L_LOG, "Sent SIG%s to all processes", "TERM"); sync(); sleep(1); - message(L_CONSOLE, "Sending SIG%s to all processes", "KILL"); kill(-1, SIGKILL); + message(L_CONSOLE, "Sent SIG%s to all processes", "KILL"); sync(); - sleep(1); + /*sleep(1); - callers take care about making a pause */ } /* Signal handling by init: @@ -684,12 +669,13 @@ static void kill_all_processes(void) * and only one will be remebered and acted upon. */ +static void halt_reboot_pwoff(int sig) NORETURN; static void halt_reboot_pwoff(int sig) { const char *m; unsigned rb; - kill_all_processes(); + run_shutdown_and_kill_processes(); m = "halt"; rb = RB_HALT_SYSTEM; @@ -701,7 +687,7 @@ static void halt_reboot_pwoff(int sig) rb = RB_POWER_OFF; } message(L_CONSOLE, "Requesting system %s", m); - low_level_reboot(rb); + pause_and_low_level_reboot(rb); /* not reached */ } @@ -752,11 +738,21 @@ static void restart_handler(int sig UNUSED_PARAM) * Thus don't need to worry about preserving errno * and such. */ - kill_all_processes(); - open_stdio_to_tty(a->terminal, 0 /* - halt if open fails */); - messageD(L_CONSOLE, "Trying to re-exec %s", a->command); - init_exec(a->command); - low_level_reboot(RB_HALT_SYSTEM); + run_shutdown_and_kill_processes(); + + /* Allow Ctrl-Alt-Del to reboot the system. + * This is how kernel sets it up for init, we follow suit. + */ + reboot(RB_ENABLE_CAD); /* misnomer */ + + if (open_stdio_to_tty(a->terminal)) { + dbg_message(L_CONSOLE, "Trying to re-exec %s", a->command); + while (wait(NULL) > 0) + continue; + init_exec(a->command); + } + /* Open or exec failed */ + pause_and_low_level_reboot(RB_HALT_SYSTEM); /* not reached */ } } @@ -764,40 +760,50 @@ static void restart_handler(int sig UNUSED_PARAM) #if ENABLE_FEATURE_USE_INITTAB static void reload_inittab(void) { - struct init_action *a, *tmp; + struct init_action *a, **nextp; message(L_LOG, "reloading /etc/inittab"); /* Disable old entries */ - for (a = init_action_list; a; a = a->next) { + for (a = init_action_list; a; a = a->next) a->action_type = ONCE; - } + /* Append new entries, or modify existing entries + * (set a->action_type) if cmd and device name + * match new ones. End result: only entries with + * a->action_type == ONCE are stale. + */ parse_inittab(); if (ENABLE_FEATURE_KILL_REMOVED) { + /* Kill stale entries */ /* Be nice and send SIGTERM first */ for (a = init_action_list; a; a = a->next) - if (a->pid != 0) + if (a->action_type == ONCE && a->pid != 0) kill(a->pid, SIGTERM); if (CONFIG_FEATURE_KILL_DELAY) { /* NB: parent will wait in NOMMU case */ if ((BB_MMU ? fork() : vfork()) == 0) { /* child */ sleep(CONFIG_FEATURE_KILL_DELAY); for (a = init_action_list; a; a = a->next) - if (a->pid != 0) + if (a->action_type == ONCE && a->pid != 0) kill(a->pid, SIGKILL); _exit(EXIT_SUCCESS); } } } - /* Remove old and unused entries */ - for (a = init_action_list; a; a = tmp) { - tmp = a->next; - if (a->action_type & (ONCE | SYSINIT | WAIT)) - delete_init_action(a); + /* Remove stale (ONCE) and not useful (SYSINIT,WAIT) entries */ + nextp = &init_action_list; + while ((a = *nextp) != NULL) { + if (a->action_type & (ONCE | SYSINIT | WAIT)) { + *nextp = a->next; + free(a); + } else { + nextp = &a->next; + } } + /* Not needed: */ /* run_actions(RESPAWN | ASKFIRST); */ /* - we return to main loop, which does this automagically */ |