selftests/xsk: fail single test instead of all tests

In a number of places at en error, exit_with_error() is called that
terminates the whole test suite. This is not always desirable as it
would be more logical to only fail that test and then go along with
the other ones. So change this in a number of places in which I
thought it would be more logical to just fail the test in
question. Examples of this are in code that is only used by a single
test.

Also delete a pointless if-statement in receive_pkts() that has an
exit_with_error() in it. It can never occur since the return value is
an unsigned and the test is for less than zero.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230914084900.492-10-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/xskxceiver.c

@@ -947,36 +947,42 @@ static bool is_pkt_valid(struct pkt *pkt, void *buffer, u64 addr, u32 len)
 	return true;
 }
 
-static void kick_tx(struct xsk_socket_info *xsk)
+static int kick_tx(struct xsk_socket_info *xsk)
 {
 	int ret;
 
 	ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0);
 	if (ret >= 0)
-		return;
+		return TEST_PASS;
 	if (errno == ENOBUFS || errno == EAGAIN || errno == EBUSY || errno == ENETDOWN) {
 		usleep(100);
-		return;
+		return TEST_PASS;
 	}
-	exit_with_error(errno);
+	return TEST_FAILURE;
 }
 
-static void kick_rx(struct xsk_socket_info *xsk)
+static int kick_rx(struct xsk_socket_info *xsk)
 {
 	int ret;
 
 	ret = recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);
 	if (ret < 0)
-		exit_with_error(errno);
+		return TEST_FAILURE;
+
+	return TEST_PASS;
 }
 
 static int complete_pkts(struct xsk_socket_info *xsk, int batch_size)
 {
 	unsigned int rcvd;
 	u32 idx;
+	int ret;
 
-	if (xsk_ring_prod__needs_wakeup(&xsk->tx))
-		kick_tx(xsk);
+	if (xsk_ring_prod__needs_wakeup(&xsk->tx)) {
+		ret = kick_tx(xsk);
+		if (ret)
+			return TEST_FAILURE;
+	}
 
 	rcvd = xsk_ring_cons__peek(&xsk->umem->cq, batch_size, &idx);
 	if (rcvd) {
@@ -1024,11 +1030,14 @@ static int receive_pkts(struct test_spec *test, struct pollfd *fds)
 			return TEST_FAILURE;
 		}
 
-		kick_rx(xsk);
+		ret = kick_rx(xsk);
+		if (ret)
+			return TEST_FAILURE;
+
 		if (ifobj->use_poll) {
 			ret = poll(fds, 1, POLL_TMOUT);
 			if (ret < 0)
-				exit_with_error(errno);
+				return TEST_FAILURE;
 
 			if (!ret) {
 				if (!is_umem_valid(test->ifobj_tx))
@@ -1049,12 +1058,10 @@ static int receive_pkts(struct test_spec *test, struct pollfd *fds)
 		if (ifobj->use_fill_ring) {
 			ret = xsk_ring_prod__reserve(&umem->fq, rcvd, &idx_fq);
 			while (ret != rcvd) {
-				if (ret < 0)
-					exit_with_error(-ret);
 				if (xsk_ring_prod__needs_wakeup(&umem->fq)) {
 					ret = poll(fds, 1, POLL_TMOUT);
 					if (ret < 0)
-						exit_with_error(errno);
+						return TEST_FAILURE;
 				}
 				ret = xsk_ring_prod__reserve(&umem->fq, rcvd, &idx_fq);
 			}
@@ -1138,7 +1145,9 @@ static int __send_pkts(struct ifobject *ifobject, struct pollfd *fds, bool timeo
 	buffer_len = pkt_get_buffer_len(umem, pkt_stream->max_pkt_len);
 	/* pkts_in_flight might be negative if many invalid packets are sent */
 	if (pkts_in_flight >= (int)((umem_size(umem) - BATCH_SIZE * buffer_len) / buffer_len)) {
-		kick_tx(xsk);
+		ret = kick_tx(xsk);
+		if (ret)
+			return TEST_FAILURE;
 		return TEST_CONTINUE;
 	}
 
@@ -1321,7 +1330,9 @@ static int validate_rx_dropped(struct ifobject *ifobject)
 	struct xdp_statistics stats;
 	int err;
 
-	kick_rx(ifobject->xsk);
+	err = kick_rx(ifobject->xsk);
+	if (err)
+		return TEST_FAILURE;
 
 	err = get_xsk_stats(xsk, &stats);
 	if (err)
@@ -1347,7 +1358,9 @@ static int validate_rx_full(struct ifobject *ifobject)
 	int err;
 
 	usleep(1000);
-	kick_rx(ifobject->xsk);
+	err = kick_rx(ifobject->xsk);
+	if (err)
+		return TEST_FAILURE;
 
 	err = get_xsk_stats(xsk, &stats);
 	if (err)
@@ -1366,7 +1379,9 @@ static int validate_fill_empty(struct ifobject *ifobject)
 	int err;
 
 	usleep(1000);
-	kick_rx(ifobject->xsk);
+	err = kick_rx(ifobject->xsk);
+	if (err)
+		return TEST_FAILURE;
 
 	err = get_xsk_stats(xsk, &stats);
 	if (err)
@@ -1775,7 +1790,7 @@ static int testapp_bidirectional(struct test_spec *test)
 	return res;
 }
 
-static void swap_xsk_resources(struct ifobject *ifobj_tx, struct ifobject *ifobj_rx)
+static int swap_xsk_resources(struct ifobject *ifobj_tx, struct ifobject *ifobj_rx)
 {
 	int ret;
 
@@ -1786,7 +1801,9 @@ static void swap_xsk_resources(struct ifobject *ifobj_tx, struct ifobject *ifobj
 
 	ret = xsk_update_xskmap(ifobj_rx->xskmap, ifobj_rx->xsk->xsk);
 	if (ret)
-		exit_with_error(errno);
+		return TEST_FAILURE;
+
+	return TEST_PASS;
 }
 
 static int testapp_xdp_prog_cleanup(struct test_spec *test)
@@ -1796,7 +1813,8 @@ static int testapp_xdp_prog_cleanup(struct test_spec *test)
 	if (testapp_validate_traffic(test))
 		return TEST_FAILURE;
 
-	swap_xsk_resources(test->ifobj_tx, test->ifobj_rx);
+	if (swap_xsk_resources(test->ifobj_tx, test->ifobj_rx))
+		return TEST_FAILURE;
 	return testapp_validate_traffic(test);
 }
 
@@ -1997,11 +2015,15 @@ static int testapp_xdp_metadata_copy(struct test_spec *test)
 	test->ifobj_rx->use_metadata = true;
 
 	data_map = bpf_object__find_map_by_name(skel_rx->obj, "xsk_xdp_.bss");
-	if (!data_map || !bpf_map__is_internal(data_map))
-		exit_with_error(ENOMEM);
+	if (!data_map || !bpf_map__is_internal(data_map)) {
+		ksft_print_msg("Error: could not find bss section of XDP program\n");
+		return TEST_FAILURE;
+	}
 
-	if (bpf_map_update_elem(bpf_map__fd(data_map), &key, &count, BPF_ANY))
-		exit_with_error(errno);
+	if (bpf_map_update_elem(bpf_map__fd(data_map), &key, &count, BPF_ANY)) {
+		ksft_print_msg("Error: could not update count element\n");
+		return TEST_FAILURE;
+	}
 
 	return testapp_validate_traffic(test);
 }