Patch from Dan Langlois <dan@somanetworks.com> Support SIGSTOP/SIGCONT

for wierd situations when people want init to actualy stop doing
anything for a while...

1 files changed, 31 insertions, 0 deletions

diff --git a/init/init.c b/init/init.c
index 8e2368306..d0beb2a9a 100644
--- a/init/init.c
+++ b/init/init.c
@@ -181,6 +181,7 @@ static char *log           = VC_5;
 static int  kernelVersion  = 0;
 static char termType[32]   = "TERM=linux";
 static char console[32]    = _PATH_CONSOLE;
+sig_atomic_t got_cont = 0;
 
 static void delete_initAction(initAction * action);
 
@@ -473,6 +474,9 @@ static pid_t run(char *command, char *terminal, int get_enter)
                 signal(SIGINT, SIG_DFL);
                 signal(SIGTERM, SIG_DFL);
                 signal(SIGHUP, SIG_DFL);
+                signal(SIGCONT, SIG_DFL);
+                signal(SIGSTOP, SIG_DFL);
+                signal(SIGTSTP, SIG_DFL);
 
                 if ((fd = device_open(terminal, O_RDWR)) < 0) {
                         if (stat(terminal, &sb) != 0) {
@@ -652,6 +656,9 @@ static void shutdown_system(void)
         sigaddset(&block_signals, SIGUSR2);
         sigaddset(&block_signals, SIGINT);
         sigaddset(&block_signals, SIGTERM);
+        sigaddset(&block_signals, SIGCONT);
+        sigaddset(&block_signals, SIGSTOP);
+        sigaddset(&block_signals, SIGTSTP);
         sigprocmask(SIG_BLOCK, &block_signals, NULL);
 
         /* Allow Ctrl-Alt-Del to reboot system. */
@@ -726,6 +733,27 @@ static void ctrlaltdel_signal(int sig)
         run_actions(CTRLALTDEL);
 }
 
+/*
+ *      The SIGSTOP & SIGTSTP handler
+ */
+static void stop_handler(int sig)
+{
+        int     saved_errno = errno;
+
+        got_cont = 0;
+        while(!got_cont) pause();
+        got_cont = 0;
+        errno = saved_errno;
+}
+
+/*
+ *  The SIGCONT handler
+ */ 
+static void cont_handler(int sig)
+{
+        got_cont = 1;
+}
+
 #endif                                                  /* ! DEBUG_INIT */
 
 static void new_initAction(initActionEnum action, char *process, char *cons)
@@ -925,6 +953,9 @@ extern int init_main(int argc, char **argv)
         signal(SIGUSR2, halt_signal);
         signal(SIGINT, ctrlaltdel_signal);
         signal(SIGTERM, reboot_signal);
+        signal(SIGCONT, cont_handler);
+        signal(SIGSTOP, stop_handler);
+        signal(SIGTSTP, stop_handler);
 
         /* Turn off rebooting via CTL-ALT-DEL -- we get a 
          * SIGINT on CAD so we can shut things down gracefully... */