Regress for the dup2(2) vs accept(2) race.

Note that you need a new kernel otherwise this test will make your
machine panic!

3 files changed, 112 insertions, 2 deletions

diff --git a/regress/sys/kern/Makefile b/regress/sys/kern/Makefile
index 70077bf101e..0d0a08d69f8 100644
--- a/regress/sys/kern/Makefile
+++ b/regress/sys/kern/Makefile
@@ -1,6 +1,7 @@
-#	$OpenBSD: Makefile,v 1.70 2017/07/07 23:15:27 bluhm Exp $
+#	$OpenBSD: Makefile,v 1.71 2018/05/28 09:04:44 mpi Exp $
 
-SUBDIR+= __syscall access accept dup2 dup2_self exec_self execve exit extent
+SUBDIR+= __syscall access accept dup2 dup2_accept dup2_self
+SUBDIR+= exec_self execve exit extent
 SUBDIR+= fchdir
 SUBDIR+= fcntl_dup
 SUBDIR+= flock
diff --git a/regress/sys/kern/dup2_accept/Makefile b/regress/sys/kern/dup2_accept/Makefile
new file mode 100644
index 00000000000..80d56efa22a
--- /dev/null
+++ b/regress/sys/kern/dup2_accept/Makefile
@@ -0,0 +1,10 @@
+#	$OpenBSD: Makefile,v 1.1 2018/05/28 09:04:44 mpi Exp $
+
+PROG=	dup2_accept
+
+LIBPTHREAD=     /usr/lib/libpthread.a
+
+LDADD+=         -lpthread
+DPADD+=         ${LIBPTHREAD}
+
+.include <bsd.regress.mk>
diff --git a/regress/sys/kern/dup2_accept/dup2_accept.c b/regress/sys/kern/dup2_accept/dup2_accept.c
new file mode 100644
index 00000000000..102d2975ef6
--- /dev/null
+++ b/regress/sys/kern/dup2_accept/dup2_accept.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2018 Martin Pieuchot
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#include <assert.h>
+#include <err.h>
+#include <errno.h>
+#include <pthread.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <stdlib.h>
+
+/*
+ * Listen on localhost:TEST_PORT for a connection
+ */
+#define	TEST_PORT       9876
+
+static void *
+dupper(void *arg)
+{
+	struct sockaddr_in addr;
+	int s;
+
+	sleep(1);
+
+	s = socket(PF_INET, SOCK_STREAM, 0);
+	if (s == -1)
+		err(1, "socket");
+
+	assert(s == 5);
+
+	/*
+	 * Make sure that dup'ing a LARVAL file fails with EBUSY.
+	 *
+	 * Otherwise abort the program before calling connect(2),
+	 * this was previously panic'ing the kernel.
+	 */
+	if ((dup2(0, 4) != 4) && (errno != EBUSY))
+		err(1, "dup2");
+
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+	addr.sin_port = htons(TEST_PORT);
+
+	if (connect(5, (struct sockaddr *)&addr, sizeof(addr)) == -1)
+		err(1, "connect");
+
+	return NULL;
+}
+
+int
+main(void)
+{
+	struct sockaddr_in serv_addr;
+	struct sockaddr client_addr;
+	int error, s, len, fd;
+	pthread_t tr;
+
+	if ((error = pthread_create(&tr, NULL, dupper, NULL)))
+		errc(1, error, "pthread_create");
+
+	s = socket(PF_INET, SOCK_STREAM, 0);
+	if (s == -1)
+		err(1, "socket");
+
+	assert(s == 3);
+
+	memset(&serv_addr, 0, sizeof(serv_addr));
+	serv_addr.sin_family = AF_INET;
+        serv_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+        serv_addr.sin_port = htons(TEST_PORT);
+
+        if (bind(s, (struct sockaddr *)&serv_addr, sizeof(serv_addr)))
+		err(1, "bind");
+
+        if (listen(s, 3))
+        	err(1, "listen");
+
+	len = sizeof(client_addr);
+	fd = accept(s, &client_addr, &len);
+
+	return 0;
+}