aboutsummaryrefslogtreecommitdiff
path: root/init
diff options
context:
space:
mode:
authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2009-01-31 18:55:54 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2009-01-31 18:55:54 +0000
commit4ae8a05b131836184eb32c440a6bf814ff81b069 (patch)
treef64538f2ec02df64b8cf37016df31113684858bb /init
parente35af567900ec2a7abb17e09cc5b5641f7faafe7 (diff)
downloadbusybox-4ae8a05b131836184eb32c440a6bf814ff81b069.tar.gz
busybox-4ae8a05b131836184eb32c440a6bf814ff81b069.tar.bz2
init: fix a bug where on reload order of entries might be wrong
function old new delta run_shutdown_and_kill_processes - 97 +97 pause_and_low_level_reboot - 48 +48 run_actions 81 107 +26 restart_handler 56 81 +25 new_init_action 137 150 +13 run 576 579 +3 open_stdio_to_tty 110 98 -12 check_delayed_sigs 195 170 -25 waitfor 354 318 -36 low_level_reboot 53 - -53 kill_all_processes 115 - -115 ------------------------------------------------------------------------------ (add/remove: 2/2 grow/shrink: 4/3 up/down: 212/-241) Total: -29 bytes
Diffstat (limited to 'init')
-rw-r--r--init/init.c172
1 files changed, 89 insertions, 83 deletions
diff --git a/init/init.c b/init/init.c
index ed01e71c0..7ba8b67ec 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 */