Index: tests/sys/net/routing/rtsock_config.h
===================================================================
--- tests/sys/net/routing/rtsock_config.h
+++ tests/sys/net/routing/rtsock_config.h
@@ -126,8 +126,15 @@
 	inet_ntop(AF_INET6, &c->net6.sin6_addr, c->net6_str, INET6_ADDRSTRLEN);
 	inet_ntop(AF_INET6, &c->addr6.sin6_addr, c->addr6_str, INET6_ADDRSTRLEN);
 
+	ATF_CHECK_ERRNO(0, true);
+
 	if (co->num_interfaces > 0) {
-		kldload("if_epair");
+		if (kldload("if_epair") == -1) {
+			/* Any errno other than EEXIST is fatal. */
+			ATF_REQUIRE_ERRNO(EEXIST, true);
+			/* Clear errno for the following tests. */
+			errno = 0;
+		}
 		ATF_REQUIRE_KERNEL_MODULE("if_epair");
 
 		c->ifnames = calloc(co->num_interfaces, sizeof(char *));
Index: tests/sys/net/routing/test_rtsock_l3.c
===================================================================
--- tests/sys/net/routing/test_rtsock_l3.c
+++ tests/sys/net/routing/test_rtsock_l3.c
@@ -64,6 +64,7 @@
 
 	ret = iface_enable_ipv6(c->ifname);
 	ATF_REQUIRE_MSG(ret == 0, "Unable to enable IPv6 on %s", c->ifname);
+	ATF_REQUIRE_ERRNO(0, true);
 
 	return (c);
 }
@@ -79,6 +80,7 @@
 	ret = iface_setup_addr(c->ifname, c->addr6_str, c->plen6);
 
 	c->rtsock_fd = rtsock_setup_socket();
+	ATF_REQUIRE_ERRNO(0, true);
 
 	return (c);
 }
@@ -90,11 +92,13 @@
 	int ret;
 
 	c = config_setup(tc, NULL);
+	ATF_REQUIRE(c != NULL);
 
 	jump_vnet(c, tc);
 
 	ret = iface_turn_up(c->ifname);
 	ATF_REQUIRE_MSG(ret == 0, "Unable to turn up %s", c->ifname);
+	ATF_REQUIRE_ERRNO(0, true);
 
 	return (c);
 }
@@ -112,6 +116,7 @@
 	ATF_REQUIRE_MSG(ret == 0, "ifconfig failed");
 
 	c->rtsock_fd = rtsock_setup_socket();
+	ATF_REQUIRE_ERRNO(0, true);
 
 	return (c);
 }
@@ -365,7 +370,7 @@
 	    (struct sockaddr *)&c->mask4, NULL);
 	rtsock_update_rtm_len(rtm);
 
-	ATF_CHECK_ERRNO(EINVAL, write(c->rtsock_fd, rtm, rtm->rtm_msglen));
+	ATF_CHECK_ERRNO(EINVAL, write(c->rtsock_fd, rtm, rtm->rtm_msglen) == -1);
 }
 
 ATF_TC_CLEANUP(rtm_get_v4_empty_dst_failure, tc)
@@ -373,16 +378,17 @@
 	CLEANUP_AFTER_TEST;
 }
 
-ATF_TC_WITH_CLEANUP(rtm_get_v4_hostbits_failure);
-ATF_TC_HEAD(rtm_get_v4_hostbits_failure, tc)
+ATF_TC_WITH_CLEANUP(rtm_get_v4_hostbits_success);
+ATF_TC_HEAD(rtm_get_v4_hostbits_success, tc)
 {
 	DESCRIBE_ROOT_TEST("Tests RTM_GET with prefix with some hosts-bits set");
 }
 
-ATF_TC_BODY(rtm_get_v4_hostbits_failure, tc)
+ATF_TC_BODY(rtm_get_v4_hostbits_success, tc)
 {
 	DECLARE_TEST_VARS;
 
+	errno = 0;
 	c = presetup_ipv4(tc);
 
 	/* Q the same prefix */
@@ -390,10 +396,11 @@
 	    (struct sockaddr *)&c->mask4, NULL);
 	rtsock_update_rtm_len(rtm);
 
-	ATF_CHECK_ERRNO(ESRCH, write(c->rtsock_fd, rtm, rtm->rtm_msglen));
+	ATF_REQUIRE_ERRNO(0, true);
+	ATF_CHECK_ERRNO(0, write(c->rtsock_fd, rtm, rtm->rtm_msglen) > 0);
 }
 
-ATF_TC_CLEANUP(rtm_get_v4_hostbits_failure, tc)
+ATF_TC_CLEANUP(rtm_get_v4_hostbits_success, tc)
 {
 	CLEANUP_AFTER_TEST;
 }
@@ -440,10 +447,10 @@
 	CLEANUP_AFTER_TEST;
 }
 
-RTM_DECLARE_ROOT_TEST(rtm_add_v4_no_rtf_host_failure,
-    "Tests failure with netmask sa and RTF_HOST inconsistency");
+RTM_DECLARE_ROOT_TEST(rtm_add_v4_no_rtf_host_success,
+    "Tests success with netmask sa and RTF_HOST inconsistency");
 
-ATF_TC_BODY(rtm_add_v4_no_rtf_host_failure, tc)
+ATF_TC_BODY(rtm_add_v4_no_rtf_host_success, tc)
 {
 	DECLARE_TEST_VARS;
 
@@ -460,8 +467,8 @@
 	rtsock_update_rtm_len(rtm);
 
 	/* RTF_HOST is NOT specified, while netmask is empty */
-
-	ATF_CHECK_ERRNO(EINVAL, write(c->rtsock_fd, rtm, rtm->rtm_msglen));
+	ATF_REQUIRE_ERRNO(0, true);
+	ATF_CHECK_ERRNO(0, write(c->rtsock_fd, rtm, rtm->rtm_msglen) > 0);
 }
 
 ATF_TC_WITH_CLEANUP(rtm_del_v4_prefix_nogw_success);
@@ -1387,9 +1394,9 @@
 {
 	ATF_TP_ADD_TC(tp, rtm_get_v4_exact_success);
 	ATF_TP_ADD_TC(tp, rtm_get_v4_lpm_success);
-	ATF_TP_ADD_TC(tp, rtm_get_v4_hostbits_failure);
+	ATF_TP_ADD_TC(tp, rtm_get_v4_hostbits_success);
 	ATF_TP_ADD_TC(tp, rtm_get_v4_empty_dst_failure);
-	ATF_TP_ADD_TC(tp, rtm_add_v4_no_rtf_host_failure);
+	ATF_TP_ADD_TC(tp, rtm_add_v4_no_rtf_host_success);
 	ATF_TP_ADD_TC(tp, rtm_add_v4_gw_direct_success);
 	ATF_TP_ADD_TC(tp, rtm_del_v4_prefix_nogw_success);
 	ATF_TP_ADD_TC(tp, rtm_add_v6_gu_gw_gu_direct_success);