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4ae8a05b1

Denis Vlasenko

2009-01-31

FAILED Duration: 35s

Subject

init: fix a bug where on reload order of entries might be wrong

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No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

init/init.c +89 -83

init/init.c+89 -83

@@ -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 */