Block all signals before sending SIGTERM to all non-system processes.

This ensures that we reach the call to reboot(2) without being killed
by some other process.  OK deraadt@ nicm@

diff --git a/sbin/reboot/reboot.c b/sbin/reboot/reboot.c
index bcf03e0..dc5f96d 100644 (file)
--- a/sbin/reboot/reboot.c
+++ b/sbin/reboot/reboot.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: reboot.c,v 1.30 2009/10/27 23:59:34 deraadt Exp $     */
+/*     $OpenBSD: reboot.c,v 1.31 2010/07/23 20:14:23 millert Exp $     */
 /*     $NetBSD: reboot.c,v 1.8 1995/10/05 05:36:22 mycroft Exp $       */
 
 /*
@@ -62,6 +62,7 @@ main(int argc, char *argv[])
        struct passwd *pw;
        int ch, howto, lflag, nflag, pflag, qflag;
        char *p, *user;
+       sigset_t mask;
 
        p = __progname;
 
@@ -192,6 +193,13 @@ main(int argc, char *argv[])
                }
        }
 
+       /*
+        * Point of no return, block all signals so we are sure to
+        * reach the call to reboot(2) unmolested.
+        */
+       sigfillset(&mask);
+       sigprocmask(SIG_BLOCK, &mask, NULL);
+
        /* Send a SIGTERM first, a chance to save the buffers. */
        if (kill(-1, SIGTERM) == -1) {
                /*