6462151 iostat can hang if parent process has blocked SIGUSR1

1 files changed, 7 insertions, 0 deletions

diff --git a/usr/src/cmd/stat/iostat/iostat.c b/usr/src/cmd/stat/iostat/iostat.c
index c26080eed9..0507d21883 100644
--- a/usr/src/cmd/stat/iostat/iostat.c
+++ b/usr/src/cmd/stat/iostat/iostat.c
@@ -18,6 +18,7 @@
  *
  * CDDL HEADER END
  */
+
 /*
  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
@@ -1732,10 +1733,16 @@ set_timer(int interval)
 	itimerspec_t time_struct;
 	struct sigevent sig_struct;
 	struct sigaction act;
+	sigset_t sig_set;
 
 	bzero(&sig_struct, sizeof (struct sigevent));
 	bzero(&act, sizeof (struct sigaction));
 
+	/* Ensure that our signal is unblocked. */
+	(void) sigemptyset(&sig_set);
+	(void) sigaddset(&sig_set, SIGUSR1);
+	(void) sigprocmask(SIG_UNBLOCK, &sig_set, NULL);
+
 	/* Create timer */
 	sig_struct.sigev_notify = SIGEV_SIGNAL;
 	sig_struct.sigev_signo = SIGUSR1;