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).
diff --git a/init/init.c b/init/init.c
index 0c8dc89..8508511 100644
--- a/init/init.c
+++ b/init/init.c
@@ -453,6 +453,7 @@
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 @@
/* 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 @@
/* 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 @@
/* 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);