MFC r261748:

So, it turns out SIGCHLD is discarded by default, so we have to set up
a dummy handler to make it interrupt an ioctl(2) or select(2).

This makes those short-lived iscsid(8) zombies disappear.

Sponsored by:	The FreeBSD Foundation

1 files changed, 28 insertions, 0 deletions

diff --git a/usr.sbin/iscsid/iscsid.c b/usr.sbin/iscsid/iscsid.c
index c22d7fd..7504eb9 100644
--- a/usr.sbin/iscsid/iscsid.c
+++ b/usr.sbin/iscsid/iscsid.c
@@ -394,6 +394,32 @@ set_timeout(int timeout)
 }
 
 static void
+sigchld_handler(int dummy __unused)
+{
+
+	/*
+	 * The only purpose of this handler is to make SIGCHLD
+	 * interrupt the ISCSIDWAIT ioctl(2), so we can call
+	 * wait_for_children().
+	 */
+}
+
+static void
+register_sigchld(void)
+{
+	struct sigaction sa;
+	int error;
+
+	bzero(&sa, sizeof(sa));
+	sa.sa_handler = sigchld_handler;
+	sigfillset(&sa.sa_mask);
+	error = sigaction(SIGCHLD, &sa, NULL);
+	if (error != 0)
+		log_err(1, "sigaction");
+
+}
+
+static void
 handle_request(int iscsi_fd, const struct iscsi_daemon_request *request, int timeout)
 {
 	struct connection *conn;
@@ -522,6 +548,8 @@ main(int argc, char **argv)
 
 	pidfile_write(pidfh);
 
+	register_sigchld();
+
 	for (;;) {
 		log_debugx("waiting for request from the kernel");