init: reinstate proper handling of !ENABLE_FEATURE_USE_INITTAB

diff --git a/init/init.c b/init/init.c
index 6ff9953..cea30c9 100644 (file)
--- a/init/init.c
+++ b/init/init.c
@@ -13,25 +13,15 @@
 #include <syslog.h>
 #include <paths.h>
 #include <sys/reboot.h>
+#include <sys/resource.h>
 
 /* Was a CONFIG_xxx option. A lot of people were building
  * not fully functional init by switching it on! */
 #define DEBUG_INIT 0
 
-#define COMMAND_SIZE 256
+#define COMMAND_SIZE      256
 #define CONSOLE_NAME_SIZE 32
-#define MAXENV 16              /* Number of env. vars */
 
-/*
- * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
- * before processes are spawned to set core file size as unlimited.
- * This is for debugging only.  Don't use this is production, unless
- * you want core dumps lying about....
- */
-#define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
-#include <sys/resource.h>
-
-#define INITTAB      "/etc/inittab"    /* inittab file location */
 #ifndef INIT_SCRIPT
 #define INIT_SCRIPT  "/etc/init.d/rcS" /* Default sysinit script. */
 #endif
@@ -56,7 +46,6 @@ struct init_action {
        char command[COMMAND_SIZE];
 };
 
-/* Static variables */
 static struct init_action *init_action_list = NULL;
 
 static const char *log_console = VC_5;
@@ -74,7 +63,6 @@ enum {
 #endif
 };
 
-/* Function prototypes */
 static void halt_reboot_pwoff(int sig) NORETURN;
 
 static void waitfor(pid_t pid)
@@ -445,9 +433,14 @@ static pid_t run(const struct init_action *a)
                        continue;
        }
 
+       /*
+        * When a file named /.init_enable_core exists, setrlimit is called
+        * before processes are spawned to set core file size as unlimited.
+        * This is for debugging only.  Don't use this is production, unless
+        * you want core dumps lying about....
+        */
        if (ENABLE_FEATURE_INIT_COREDUMPS) {
-               struct stat sb;
-               if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
+               if (access("/.init_enable_core", F_OK) == 0) {
                        struct rlimit limit;
                        limit.rlim_cur = RLIM_INFINITY;
                        limit.rlim_max = RLIM_INFINITY;
@@ -665,15 +658,14 @@ static void new_init_action(uint8_t action_type, const char *command, const char
  */
 static void parse_inittab(void)
 {
+#if ENABLE_FEATURE_USE_INITTAB
        char *token[4];
-       /* order must correspond to SYSINIT..RESTART constants */
-       static const char actions[] ALIGN1 =
-               "sysinit\0""respawn\0""askfirst\0""wait\0""once\0"
-               "ctrlaltdel\0""shutdown\0""restart\0";
-
-       parser_t *parser = config_open2(INITTAB, fopen_for_read);
-       /* No inittab file -- set up some default behavior */
-       if (parser == NULL) {
+       parser_t *parser = config_open2("/etc/inittab", fopen_for_read);
+
+       if (parser == NULL)
+#endif
+       {
+               /* No inittab file -- set up some default behavior */
                /* Reboot on Ctrl-Alt-Del */
                new_init_action(CTRLALTDEL, "reboot", "");
                /* Umount all filesystems on halt/reboot */
@@ -693,11 +685,17 @@ static void parse_inittab(void)
                new_init_action(SYSINIT, INIT_SCRIPT, "");
                return;
        }
+
+#if ENABLE_FEATURE_USE_INITTAB
        /* optional_tty:ignored_runlevel:action:command
         * Delims are not to be collapsed and need exactly 4 tokens
         */
        while (config_read(parser, token, 4, 0, "#:",
                                PARSE_NORMAL & ~(PARSE_TRIM | PARSE_COLLAPSE))) {
+               /* order must correspond to SYSINIT..RESTART constants */
+               static const char actions[] ALIGN1 =
+                       "sysinit\0""respawn\0""askfirst\0""wait\0""once\0"
+                       "ctrlaltdel\0""shutdown\0""restart\0";
                int action;
                char *tty = token[0];
 
@@ -721,6 +719,7 @@ static void parse_inittab(void)
                                parser->lineno);
        }
        config_close(parser);
+#endif
 }
 
 #if ENABLE_FEATURE_USE_INITTAB
@@ -794,6 +793,10 @@ int init_main(int argc UNUSED_PARAM, char **argv)
                }
                /* Set up sig handlers  -- be sure to
                 * clear all of these in run() */
+// TODO: handlers should just set a flag variable.
+// Move signal handling from handlers to main loop -
+// we have bad races otherwise.
+// E.g. parse_inittab() vs. delete_init_action()...
                signal(SIGQUIT, exec_restart_action);
                bb_signals(0
                        + (1 << SIGUSR1)  /* halt */
@@ -834,9 +837,9 @@ int init_main(int argc UNUSED_PARAM, char **argv)
        if (ENABLE_SWAPONOFF) {
                struct sysinfo info;
 
-               if (!sysinfo(&info) &&
-                       (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024)
-               {
+               if (sysinfo(&info) == 0
+                && (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024
+               ) {
                        message(L_CONSOLE, "Low memory, forcing swapon");
                        /* swapon -a requires /proc typically */
                        new_init_action(SYSINIT, "mount -t proc proc /proc", "");
@@ -877,7 +880,7 @@ int init_main(int argc UNUSED_PARAM, char **argv)
                        exit(EXIT_FAILURE);
                }
        }
-#endif /* CONFIG_SELINUX */
+#endif
 
        /* Make the command line just say "init"  - thats all, nothing else */
        strncpy(argv[0], "init", strlen(argv[0]));