Merge branch 'bpf-vsock-fix-poll-and-close'

Michal Luczaj says:

====================
bpf, vsock: Fix poll() and close()

Two small fixes for vsock: poll() missing a queue check, and close() not
invoking sockmap cleanup.

Signed-off-by: Michal Luczaj <mhal@rbox.co>
Acked-by: John Fastabend <john.fastabend@gmail.com>
---
====================

Link: https://patch.msgid.link/20241118-vsock-bpf-poll-close-v1-0-f1b9669cacdc@rbox.co
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

net/vmw_vsock/af_vsock.c

@@ -117,12 +117,14 @@
 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
 static void vsock_sk_destruct(struct sock *sk);
 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
+static void vsock_close(struct sock *sk, long timeout);
 
 /* Protocol family. */
 struct proto vsock_proto = {
 	.name = "AF_VSOCK",
 	.owner = THIS_MODULE,
 	.obj_size = sizeof(struct vsock_sock),
+	.close = vsock_close,
 #ifdef CONFIG_BPF_SYSCALL
 	.psock_update_sk_prot = vsock_bpf_update_proto,
 #endif
@@ -797,39 +799,37 @@ static bool sock_type_connectible(u16 type)
 
 static void __vsock_release(struct sock *sk, int level)
 {
-	if (sk) {
-		struct sock *pending;
-		struct vsock_sock *vsk;
-
-		vsk = vsock_sk(sk);
-		pending = NULL;	/* Compiler warning. */
+	struct vsock_sock *vsk;
+	struct sock *pending;
 
-		/* When "level" is SINGLE_DEPTH_NESTING, use the nested
-		 * version to avoid the warning "possible recursive locking
-		 * detected". When "level" is 0, lock_sock_nested(sk, level)
-		 * is the same as lock_sock(sk).
-		 */
-		lock_sock_nested(sk, level);
+	vsk = vsock_sk(sk);
+	pending = NULL;	/* Compiler warning. */
 
-		if (vsk->transport)
-			vsk->transport->release(vsk);
-		else if (sock_type_connectible(sk->sk_type))
-			vsock_remove_sock(vsk);
+	/* When "level" is SINGLE_DEPTH_NESTING, use the nested
+	 * version to avoid the warning "possible recursive locking
+	 * detected". When "level" is 0, lock_sock_nested(sk, level)
+	 * is the same as lock_sock(sk).
+	 */
+	lock_sock_nested(sk, level);
 
-		sock_orphan(sk);
-		sk->sk_shutdown = SHUTDOWN_MASK;
+	if (vsk->transport)
+		vsk->transport->release(vsk);
+	else if (sock_type_connectible(sk->sk_type))
+		vsock_remove_sock(vsk);
 
-		skb_queue_purge(&sk->sk_receive_queue);
+	sock_orphan(sk);
+	sk->sk_shutdown = SHUTDOWN_MASK;
 
-		/* Clean up any sockets that never were accepted. */
-		while ((pending = vsock_dequeue_accept(sk)) != NULL) {
-			__vsock_release(pending, SINGLE_DEPTH_NESTING);
-			sock_put(pending);
-		}
+	skb_queue_purge(&sk->sk_receive_queue);
 
-		release_sock(sk);
-		sock_put(sk);
+	/* Clean up any sockets that never were accepted. */
+	while ((pending = vsock_dequeue_accept(sk)) != NULL) {
+		__vsock_release(pending, SINGLE_DEPTH_NESTING);
+		sock_put(pending);
 	}
+
+	release_sock(sk);
+	sock_put(sk);
 }
 
 static void vsock_sk_destruct(struct sock *sk)
@@ -901,9 +901,22 @@ void vsock_data_ready(struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(vsock_data_ready);
 
+/* Dummy callback required by sockmap.
+ * See unconditional call of saved_close() in sock_map_close().
+ */
+static void vsock_close(struct sock *sk, long timeout)
+{
+}
+
 static int vsock_release(struct socket *sock)
 {
-	__vsock_release(sock->sk, 0);
+	struct sock *sk = sock->sk;
+
+	if (!sk)
+		return 0;
+
+	sk->sk_prot->close(sk, 0);
+	__vsock_release(sk, 0);
 	sock->sk = NULL;
 	sock->state = SS_FREE;
 
@@ -1054,6 +1067,9 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock,
 		mask |= EPOLLRDHUP;
 	}
 
+	if (sk_is_readable(sk))
+		mask |= EPOLLIN | EPOLLRDNORM;
+
 	if (sock->type == SOCK_DGRAM) {
 		/* For datagram sockets we can read if there is something in
 		 * the queue and write as long as the socket isn't shutdown for

tools/testing/selftests/bpf/prog_tests/sockmap_basic.c

@@ -108,6 +108,35 @@ static void test_sockmap_create_update_free(enum bpf_map_type map_type)
 	close(s);
 }
 
+static void test_sockmap_vsock_delete_on_close(void)
+{
+	int err, c, p, map;
+	const int zero = 0;
+
+	err = create_pair(AF_VSOCK, SOCK_STREAM, &c, &p);
+	if (!ASSERT_OK(err, "create_pair(AF_VSOCK)"))
+		return;
+
+	map = bpf_map_create(BPF_MAP_TYPE_SOCKMAP, NULL, sizeof(int),
+			     sizeof(int), 1, NULL);
+	if (!ASSERT_GE(map, 0, "bpf_map_create")) {
+		close(c);
+		goto out;
+	}
+
+	err = bpf_map_update_elem(map, &zero, &c, BPF_NOEXIST);
+	close(c);
+	if (!ASSERT_OK(err, "bpf_map_update"))
+		goto out;
+
+	err = bpf_map_update_elem(map, &zero, &p, BPF_NOEXIST);
+	ASSERT_OK(err, "after close(), bpf_map_update");
+
+out:
+	close(p);
+	close(map);
+}
+
 static void test_skmsg_helpers(enum bpf_map_type map_type)
 {
 	struct test_skmsg_load_helpers *skel;
@@ -937,12 +966,58 @@ static void test_sockmap_same_sock(void)
 	test_sockmap_pass_prog__destroy(skel);
 }
 
+static void test_sockmap_skb_verdict_vsock_poll(void)
+{
+	struct test_sockmap_pass_prog *skel;
+	int err, map, conn, peer;
+	struct bpf_program *prog;
+	struct bpf_link *link;
+	char buf = 'x';
+	int zero = 0;
+
+	skel = test_sockmap_pass_prog__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		return;
+
+	if (create_pair(AF_VSOCK, SOCK_STREAM, &conn, &peer))
+		goto destroy;
+
+	prog = skel->progs.prog_skb_verdict;
+	map = bpf_map__fd(skel->maps.sock_map_rx);
+	link = bpf_program__attach_sockmap(prog, map);
+	if (!ASSERT_OK_PTR(link, "bpf_program__attach_sockmap"))
+		goto close;
+
+	err = bpf_map_update_elem(map, &zero, &conn, BPF_ANY);
+	if (!ASSERT_OK(err, "bpf_map_update_elem"))
+		goto detach;
+
+	if (xsend(peer, &buf, 1, 0) != 1)
+		goto detach;
+
+	err = poll_read(conn, IO_TIMEOUT_SEC);
+	if (!ASSERT_OK(err, "poll"))
+		goto detach;
+
+	if (xrecv_nonblock(conn, &buf, 1, 0) != 1)
+		FAIL("xrecv_nonblock");
+detach:
+	bpf_link__detach(link);
+close:
+	xclose(conn);
+	xclose(peer);
+destroy:
+	test_sockmap_pass_prog__destroy(skel);
+}
+
 void test_sockmap_basic(void)
 {
 	if (test__start_subtest("sockmap create_update_free"))
 		test_sockmap_create_update_free(BPF_MAP_TYPE_SOCKMAP);
 	if (test__start_subtest("sockhash create_update_free"))
 		test_sockmap_create_update_free(BPF_MAP_TYPE_SOCKHASH);
+	if (test__start_subtest("sockmap vsock delete on close"))
+		test_sockmap_vsock_delete_on_close();
 	if (test__start_subtest("sockmap sk_msg load helpers"))
 		test_skmsg_helpers(BPF_MAP_TYPE_SOCKMAP);
 	if (test__start_subtest("sockhash sk_msg load helpers"))
@@ -997,4 +1072,6 @@ void test_sockmap_basic(void)
 		test_skmsg_helpers_with_link(BPF_MAP_TYPE_SOCKMAP);
 	if (test__start_subtest("sockhash sk_msg attach sockhash helpers with link"))
 		test_skmsg_helpers_with_link(BPF_MAP_TYPE_SOCKHASH);
+	if (test__start_subtest("sockmap skb_verdict vsock poll"))
+		test_sockmap_skb_verdict_vsock_poll();
 }