Block SIGHUP before killing init(8), to avoid a race condition which may

kill the current process and hang the system when attempting reboot.

PR:		bin/64664
Reviewed by:	ssouhal, phk (historic)
MFC after:	30 days

1 files changed, 3 insertions, 3 deletions

diff --git a/sbin/reboot/reboot.c b/sbin/reboot/reboot.c
index 0a52ba4..29790b4 100644
--- a/sbin/reboot/reboot.c
+++ b/sbin/reboot/reboot.c
@@ -151,13 +151,13 @@ main(int argc, char *argv[])
 	if (!nflag)
 		sync();
 
+	/* Ignore the SIGHUP we get when our parent shell dies. */
+	(void)signal(SIGHUP, SIG_IGN);
+
 	/* Just stop init -- if we fail, we'll restart it. */
 	if (kill(1, SIGTSTP) == -1)
 		err(1, "SIGTSTP init");
 
-	/* Ignore the SIGHUP we get when our parent shell dies. */
-	(void)signal(SIGHUP, SIG_IGN);
-
 	/* Send a SIGTERM first, a chance to save the buffers. */
 	if (kill(-1, SIGTERM) == -1 && errno != ESRCH)
 		err(1, "SIGTERM processes");