jfb2 writes in Bug 119:

The init applet will restart (re-exec) itsself when it
receives a SIGHUP. However, just before it enters its
main loop, it resets SIGHUP to either re-load the inittab
(or ignore it if no inittab is used). Thus preventing
the re-exec option from being triggerable.

This patch adds a signal handler for SIGQUIT for init that
always causes init to re-exec itsself (along with killing
anything else that might be still running).


git-svn-id: svn://busybox.net/trunk/busybox@10120 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 4 insertions, 0 deletions

diff --git a/init/init.c b/init/init.c
index 0c8dc89dc..850851173 100644
--- a/init/init.c
+++ b/init/init.c
@@ -453,6 +453,7 @@ static pid_t run(const struct init_action *a)
                 signal(SIGINT, SIG_DFL);
                 signal(SIGTERM, SIG_DFL);
                 signal(SIGHUP, SIG_DFL);
+                signal(SIGQUIT, SIG_DFL);
                 signal(SIGCONT, SIG_DFL);
                 signal(SIGSTOP, SIG_DFL);
                 signal(SIGTSTP, SIG_DFL);
@@ -693,6 +694,7 @@ static void shutdown_system(void)
         /* first disable all our signals */
         sigemptyset(&block_signals);
         sigaddset(&block_signals, SIGHUP);
+        sigaddset(&block_signals, SIGQUIT);
         sigaddset(&block_signals, SIGCHLD);
         sigaddset(&block_signals, SIGUSR1);
         sigaddset(&block_signals, SIGUSR2);
@@ -737,6 +739,7 @@ static void exec_signal(int sig)
                         /* unblock all signals, blocked in shutdown_system() */
                         sigemptyset(&unblock_signals);
                         sigaddset(&unblock_signals, SIGHUP);
+                        sigaddset(&unblock_signals, SIGQUIT);
                         sigaddset(&unblock_signals, SIGCHLD);
                         sigaddset(&unblock_signals, SIGUSR1);
                         sigaddset(&unblock_signals, SIGUSR2);
@@ -1097,6 +1100,7 @@ extern int init_main(int argc, char **argv)
         /* Set up sig handlers  -- be sure to
          * clear all of these in run() */
         signal(SIGHUP, exec_signal);
+        signal(SIGQUIT, exec_signal);
         signal(SIGUSR1, halt_signal);
         signal(SIGUSR2, halt_signal);
         signal(SIGINT, ctrlaltdel_signal);