init: restore possibility to reload inittab even before we finish initialization

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/init/init.c b/init/init.c
index 5240e47a5..14136859f 100644
--- a/init/init.c
+++ b/init/init.c
@@ -40,9 +40,9 @@
 #define ONCE        0x04
 /*
  * NB: while SYSINIT/WAIT/ONCE are being processed,
- * SIGHUP ("reread /etc/inittab") will be ignored.
- * Rationale: it would be ambiguous whether SYSINIT/WAIT/ONCE
- * need to be rerun or not.
+ * SIGHUP ("reread /etc/inittab") will be processed only after
+ * each group of actions. If new inittab adds, say, a SYSINIT action,
+ * it will not be run, since init is already "past SYSINIT stage".
  */
 /* Start these after ONCE are started, restart on exit */
 #define RESPAWN     0x08
@@ -754,12 +754,12 @@ static void reload_inittab(void)
 
         /* Disable old entries */
         for (a = init_action_list; a; a = a->next)
-                a->action_type = ONCE;
+                a->action_type = 0;
 
         /* Append new entries, or modify existing entries
-         * (set a->action_type) if cmd and device name
+         * (incl. setting a->action_type) if cmd and device name
          * match new ones. End result: only entries with
-         * a->action_type == ONCE are stale.
+         * a->action_type == 0 are stale.
          */
         parse_inittab();
 
@@ -767,24 +767,26 @@ static void reload_inittab(void)
         /* Kill stale entries */
         /* Be nice and send SIGTERM first */
         for (a = init_action_list; a; a = a->next)
-                if (a->action_type == ONCE && a->pid != 0)
+                if (a->action_type == 0 && 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->action_type == ONCE && a->pid != 0)
+                                if (a->action_type == 0 && a->pid != 0)
                                         kill(a->pid, SIGKILL);
                         _exit(EXIT_SUCCESS);
                 }
         }
 #endif
 
-        /* Remove stale (ONCE) and not useful (SYSINIT,WAIT) entries */
+        /* Remove stale entries and SYSINIT entries.
+         * We never rerun SYSINIT entries anyway,
+         * removing them too saves a few bytes */
         nextp = &init_action_list;
         while ((a = *nextp) != NULL) {
-                if (a->action_type & (ONCE | SYSINIT | WAIT)) {
+                if ((a->action_type & ~SYSINIT) == 0) {
                         *nextp = a->next;
                         free(a);
                 } else {
@@ -943,6 +945,12 @@ int init_main(int argc UNUSED_PARAM, char **argv)
                 bb_signals_recursive_norestart((1 << SIGINT), record_signo);
         }
 
+        /* Set up "reread /etc/inittab" handler.
+         * Handler is set up without SA_RESTART, it will interrupt syscalls.
+         */
+        if (!DEBUG_INIT && ENABLE_FEATURE_USE_INITTAB)
+                bb_signals_recursive_norestart((1 << SIGHUP), record_signo);
+
         /* Now run everything that needs to be run */
         /* First run the sysinit command */
         run_actions(SYSINIT);
@@ -953,12 +961,6 @@ int init_main(int argc UNUSED_PARAM, char **argv)
         /* Next run anything to be run only once */
         run_actions(ONCE);
 
-        /* Set up "reread /etc/inittab" handler.
-         * Handler is set up without SA_RESTART, it will interrupt syscalls.
-         */
-        if (!DEBUG_INIT && ENABLE_FEATURE_USE_INITTAB)
-                bb_signals_recursive_norestart((1 << SIGHUP), record_signo);
-
         /* Now run the looping stuff for the rest of forever.
          */
         while (1) {