Index: user/pho/stress2/misc/sctp2.sh
===================================================================
--- user/pho/stress2/misc/sctp2.sh	(revision 358736)
+++ user/pho/stress2/misc/sctp2.sh	(revision 358737)
@@ -1,167 +1,170 @@
 #!/bin/sh
 
 # Based on https://gist.github.com/zonque/7d03568eab14a2bb57cb by
 # Daniel Mack github@zonque.org
 
 # Modified version of sctp.sh by Michael Tuexen <tuexen@freebsd.org>:
 # * Use loopback as the address of the server on both side initialized using
 #   htonl(INADDR_LOOPBACK).
 # * Negotiate only 1 stream in both directions since only one stream is used.
 # * Don't use initmsg.sinit_max_instreams as an argument in listen(), which
 #   does not make sense.
 #   Use an arbitrary positive integer, 5 in this case.
 # * Initialize flags before calling sctp_recvmsg().
 
 # "panic: Don't own TCB lock" seen:
 # https://people.freebsd.org/~pho/stress/log/sctp2.txt
 
+# "panic: soclose: SS_NOFDREF on enter" seen:
+# https://people.freebsd.org/~pho/stress/log/sctp2-2.txt
+
 # $FreeBSD$
 
 cat > /tmp/sctp2.c <<EOF
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <unistd.h>
 #include <arpa/inet.h>
 #include <libgen.h>
 #include <netinet/in.h>
 #include <netinet/sctp.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 static int my_port_num;
 
 static void
 die(const char *s)
 {
 	perror(s);
 	exit(1);
 }
 
 static void
 server(void)
 {
 	struct sctp_sndrcvinfo sndrcvinfo;
 	struct sockaddr_in servaddr = {
 		.sin_family = AF_INET,
 		.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
 		.sin_port = htons(my_port_num),
 	};
 	struct sctp_initmsg initmsg = {
 		.sinit_num_ostreams = 1,
 		.sinit_max_instreams = 1,
 		.sinit_max_attempts = 4,
 	};
 	int listen_fd, conn_fd, flags, ret, in;
 
 	listen_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP);
 	if (listen_fd < 0)
 		die("socket");
 
 	ret = bind(listen_fd, (struct sockaddr *) &servaddr, sizeof(servaddr));
 	if (ret < 0)
 		die("bind");
 
 	ret = setsockopt(listen_fd, IPPROTO_SCTP, SCTP_INITMSG, &initmsg,
 			sizeof(initmsg));
 	if (ret < 0)
 		die("setsockopt");
 
 	ret = listen(listen_fd, 5);
 	if (ret < 0)
 		die("listen");
 
 	for (;;) {
 		char buffer[1024];
 
 		printf("Waiting for connection\n");
 		fflush(stdout);
 
 		conn_fd = accept(listen_fd, (struct sockaddr *) NULL, NULL);
 		if(conn_fd < 0)
 			die("accept()");
 
 		printf("New client connected\n");
 		fflush(stdout);
 
 		flags = 0;
 		in = sctp_recvmsg(conn_fd, buffer, sizeof(buffer), NULL, 0,
 				&sndrcvinfo, &flags);
 		if (in > 0) {
 			printf("Received data: %s\n", buffer);
 			fflush(stdout);
 		}
 
 		close(conn_fd);
 	}
 }
 
 static void
 client(void)
 {
 	struct sockaddr_in servaddr = {
 		.sin_family = AF_INET,
 		.sin_port = htons(my_port_num),
 		.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
 	};
 	int conn_fd, ret;
 	const char *msg = "Hello, Server!";
 
 	conn_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP);
 	if (conn_fd < 0)
 		die("socket()");
 
 	ret = connect(conn_fd, (struct sockaddr *) &servaddr, sizeof(servaddr));
 	if (ret < 0)
 		die("connect()");
 
 	ret = sctp_sendmsg(conn_fd, (void *) msg, strlen(msg) + 1, NULL, 0, 0, 0, 0, 0, 0 );
 	if (ret < 0)
 		die("sctp_sendmsg");
 
 	close(conn_fd);
 }
 
 int
 main(int argc __unused, char *argv[])
 {
 
 	my_port_num = atoi(argv[1]);
 	if (strstr(basename(argv[0]), "server"))
 		server();
 	else
 		client();
 
 	return (0);
 }
 EOF
 
 cc -o /tmp/server -Wall -Wextra -O2 /tmp/sctp2.c || exit
 ln -sf /tmp/server /tmp/client
 
 parallel=100
 for i in `jot $parallel 62324`; do
 	/tmp/server $i > /dev/null &
 done
 (cd ../testcases/swap; ./swap -t 1m -i 20 -l 100) &
 sleep 2
 
 start=`date +%s`
 while [ $((`date +%s` - start)) -lt 60 ]; do
 	pids=
 	for i in `jot 50`; do
 		for j in `jot $parallel 62324`; do
 			/tmp/client $j &
 			pids="$pids $!"
 		done
 	done
 	for i in $pids; do
 		wait $i
 	done
 done
 pkill server
 wait
 while pkill swap; do :; done
 wait
 rm -f /tmp/sctp2.c /tmp/server /tmp/client
 exit 0