ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 607 insertions, 0 deletions

diff --git a/drivers/firewire/node-tree-test.c b/drivers/firewire/node-tree-test.c
new file mode 100644
index 000000000..5e6bb5853
--- /dev/null
+++ b/drivers/firewire/node-tree-test.c
@@ -0,0 +1,607 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// node-tree-test.c - An application of Kunit to test node tree.
+//
+// Copyright (c) 2026 Takashi Sakamoto
+//
+// This file can not be built independently since it is intentionally included in core-topology.c.
+
+#include <kunit/test.h>
+#include <kunit/test-bug.h>
+#include <kunit/device.h>
+
+struct private_data {
+	struct fw_card *card;
+	unsigned int release_count;
+};
+
+static int node_tree_test_init(struct kunit *test)
+{
+	struct private_data *data;
+
+	data = kunit_kzalloc(test, sizeof(*data), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, data);
+
+	data->card = kunit_kzalloc(test, sizeof(struct fw_card), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, data->card);
+
+	data->card->device = kunit_device_register(test, "dummy-device");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, data->card->device);
+
+	test->priv = data;
+
+	return 0;
+}
+
+static void node_tree_test_exit(struct kunit *test)
+{
+	struct private_data *data = test->priv;
+
+	kunit_device_unregister(test, data->card->device);
+	kunit_kfree(test, data->card);
+	kunit_kfree(test, data);
+}
+
+static void release_fw_node(struct fw_card *card, struct fw_node *node, struct fw_node *parent)
+{
+	struct private_data *data = kunit_get_current_test()->priv;
+
+	fw_node_put(node);
+	++data->release_count;
+}
+
+static void node_tree_test_two_nodes(struct kunit *test)
+{
+	//       root
+	// ++============++
+	// ||    phy 1   ||
+	// ||  P0 P1 P2  ||
+	// ++===|==|==|==++
+	//            |
+	//      +-----+
+	//      |
+	// ++===|==x==x==++
+	// ||  P0 P1 P2  ||
+	// ||    phy 0   ||
+	// ++============++
+	//
+	static const u32 self_id_sequence[] = {
+		0x80000080,
+		0x8100005e,
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x01;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NOT_NULL(test, card->local_node);
+	KUNIT_EXPECT_PTR_EQ(test, card->local_node, card->root_node);
+
+	struct fw_node *node = card->root_node;
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x01);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[2]);
+
+	struct fw_node *parent = node;
+	node = parent->ports[2];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x00);
+	KUNIT_EXPECT_EQ(test, node->port_count, 1);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+
+	++card->color;
+	for_each_fw_node(card, card->root_node, release_fw_node);
+	KUNIT_EXPECT_EQ(test, data->release_count, 2);
+}
+
+static void node_tree_test_two_nodes_1394a(struct kunit *test)
+{
+	//         root
+	// ++===============++
+	// ||      phy 0    ||
+	// ||  P0 P1 P2 P3  ||
+	// ++===|==|==|==|==++
+	//            |
+	//         +--+
+	//         |
+	// ++===|==|==|==|==|==++
+	// ||  P0 P1 P2 P3 P4  ||
+	// ||       phy 1      ||
+	// ++==================++
+	//
+	// NOTE: Just for Self-ID Packets Zero and One.
+	static const u32 self_id_sequence[] = {
+		0x80000065, 0x80814000,
+		0x8100005d, 0x81810000,
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x01;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NOT_NULL(test, card->local_node);
+	KUNIT_EXPECT_PTR_EQ(test, card->local_node, card->root_node);
+
+	struct fw_node *node = card->root_node;
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x01);
+	KUNIT_EXPECT_EQ(test, node->port_count, 4);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[2]);
+	KUNIT_EXPECT_NULL(test, node->ports[3]);
+
+	struct fw_node *parent = node;
+	node = parent->ports[2];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x00);
+	KUNIT_EXPECT_EQ(test, node->port_count, 5);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[1], parent);
+	KUNIT_EXPECT_NULL(test, node->ports[2]);
+	KUNIT_EXPECT_NULL(test, node->ports[3]);
+	KUNIT_EXPECT_NULL(test, node->ports[4]);
+
+	++card->color;
+	for_each_fw_node(card, card->root_node, release_fw_node);
+	KUNIT_EXPECT_EQ(test, data->release_count, 2);
+}
+
+static void node_tree_test_three_nodes_case0(struct kunit *test)
+{
+	//       root
+	// ++============++
+	// ||    phy 2   ||
+	// ||  P0 P1 P2  ||
+	// ++===|==|==|==++
+	//      |     |
+	//      +--+  +-----------------+
+	//         |                    |
+	// ++===|==|==x==++  ++===|==|==|==++
+	// ||  P0 P1 P2  ||  ||  P0 P1 P2  ||
+	// ||    phy 0   ||  ||    phy 1   ||
+	// ++============++  ++============++
+	//
+	static const u32 self_id_sequence[] = {
+		0x80000060,
+		0x81000058,
+		0x820000dc,
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x02;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NOT_NULL(test, card->local_node);
+	KUNIT_EXPECT_PTR_EQ(test, card->local_node, card->root_node);
+
+	struct fw_node *node = card->root_node;
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x02);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[2]);
+
+	struct fw_node *parent = node;
+	node = parent->ports[0];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x00);
+	KUNIT_EXPECT_EQ(test, node->port_count, 2);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[1], parent);
+
+	node = parent->ports[2];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x01);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[2], parent);
+
+	++card->color;
+	for_each_fw_node(card, card->root_node, release_fw_node);
+	KUNIT_EXPECT_EQ(test, data->release_count, 3);
+}
+
+static void node_tree_test_three_nodes_case1(struct kunit *test)
+{
+	//       root
+	// ++============++
+	// ||    phy 2   ||
+	// ||  P0 P1 P2  ||
+	// ++===|==|==x==++
+	//         |
+	//         |  +-----------+
+	//         |  |           |
+	// ++===|==|==|==++  ++===|==x==x==++
+	// ||  P0 P1 P2  ||  ||  P0 P1 P2  ||
+	// ||    phy 1   ||  ||    phy 0   ||
+	// ++============++  ++============++
+	//
+	static const u32 self_id_sequence[] = {
+		0x80000080,
+		0x8100006c,
+		0x82000070,
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x02;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NOT_NULL(test, card->local_node);
+	KUNIT_EXPECT_PTR_EQ(test, card->local_node, card->root_node);
+
+	struct fw_node *node = card->root_node;
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x02);
+	KUNIT_EXPECT_EQ(test, node->port_count, 2);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[1]);
+
+	struct fw_node *parent = node;
+	node = parent->ports[1];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x01);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[1], parent);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[2]);
+
+	parent = node;
+	node = parent->ports[2];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x00);
+	KUNIT_EXPECT_EQ(test, node->port_count, 1);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+
+	++card->color;
+	for_each_fw_node(card, card->root_node, release_fw_node);
+	KUNIT_EXPECT_EQ(test, data->release_count, 3);
+}
+
+static void node_tree_test_four_nodes_case0(struct kunit *test)
+{
+	//       root
+	// ++============++
+	// ||    phy 3   ||
+	// ||  P0 P1 P2  ||
+	// ++===|==|==|==++
+	//         |
+	//         |  +-----------+  +--------------+
+	//         |  |           |  |              |
+	// ++===|==|==|==++  ++===|==|==x==++  ++===|==x==x==++
+	// ||  P0 P1 P2  ||  ||  P0 P1 P2  ||  ||  P0 P1 P2  ||
+	// ||    phy 2   ||  ||    phy 1   ||  ||    phy 0   ||
+	// ++============++  ++============++  ++============++
+	//
+	static const u32 self_id_sequence[] = {
+		0x80000080,
+		0x810000b0,
+		0x8200006c,
+		0x83000074,
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x03;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NOT_NULL(test, card->local_node);
+	KUNIT_EXPECT_PTR_EQ(test, card->local_node, card->root_node);
+
+	struct fw_node *node = card->root_node;
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x03);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NULL(test, node->ports[2]);
+
+	struct fw_node *parent = node;
+	node = parent->ports[1];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x02);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[1], parent);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[2]);
+
+	parent = node;
+	node = parent->ports[2];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x01);
+	KUNIT_EXPECT_EQ(test, node->port_count, 2);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[1]);
+
+	parent = node;
+	node = parent->ports[1];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x00);
+	KUNIT_EXPECT_EQ(test, node->port_count, 1);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+
+	++card->color;
+	for_each_fw_node(card, card->root_node, release_fw_node);
+	KUNIT_EXPECT_EQ(test, data->release_count, 4);
+}
+
+static void node_tree_test_four_nodes_case1(struct kunit *test)
+{
+	//       root
+	// ++============++
+	// ||    phy 3   ||
+	// ||  P0 P1 P2  ||
+	// ++===|==|==x==++
+	//      |
+	//      |  +--------------------------------+
+	//      |  |  +-----------+                 |
+	// ++===|==|==|==++  ++===|==x==x==++  ++===|==|==|==++
+	// ||  P0 P1 P2  ||  ||  P0 P1 P2  ||  ||  P0 P1 P2  ||
+	// ||    phy 2   ||  ||    phy 1   ||  ||    phy 0   ||
+	// ++============++  ++============++  ++============++
+	//
+	static const u32 self_id_sequence[] = {
+		0x80000094,
+		0x81000080,
+		0x820000bc,
+		0x830000d0,
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x03;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NOT_NULL(test, card->local_node);
+	KUNIT_EXPECT_PTR_EQ(test, card->local_node, card->root_node);
+
+	struct fw_node *node = card->root_node;
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x03);
+	KUNIT_EXPECT_EQ(test, node->port_count, 2);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+
+	struct fw_node *parent = node;
+	node = parent->ports[0];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x02);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[2]);
+
+	parent = node;
+	node = parent->ports[2];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x01);
+	KUNIT_EXPECT_EQ(test, node->port_count, 1);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+
+	node = parent->ports[1];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x00);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NULL(test, node->ports[2]);
+
+	++card->color;
+	for_each_fw_node(card, card->root_node, release_fw_node);
+	KUNIT_EXPECT_EQ(test, data->release_count, 4);
+}
+
+static void node_tree_test_four_nodes_case2(struct kunit *test)
+{
+	//       root
+	// ++============++
+	// ||    phy 3   ||
+	// ||  P0 P1 P2  ||
+	// ++===|==|==|==++
+	//      |     |
+	//      |     +-----------------------------+
+	//      |  +--------------+                 |
+	// ++===|==|==x==++  ++===|==|==|==++  ++===|==x==x==++
+	// ||  P0 P1 P2  ||  ||  P0 P1 P2  ||  ||  P0 P1 P2  ||
+	// ||    phy 1   ||  ||    phy 0   ||  ||    phy 2   ||
+	// ++============++  ++============++  ++============++
+	//
+	static const u32 self_id_sequence[] = {
+		0x80000094,
+		0x810000b0,
+		0x82000080,
+		0x830000dc,
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x03;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NOT_NULL(test, card->local_node);
+	KUNIT_EXPECT_PTR_EQ(test, card->local_node, card->root_node);
+
+	struct fw_node *node = card->root_node;
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x03);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[2]);
+
+	struct fw_node *parent = node;
+	node = parent->ports[2];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x02);
+	KUNIT_EXPECT_EQ(test, node->port_count, 1);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+
+	node = parent->ports[0];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x01);
+	KUNIT_EXPECT_EQ(test, node->port_count, 2);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[1]);
+
+	parent = node;
+	node = parent->ports[1];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x00);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NULL(test, node->ports[2]);
+
+	++card->color;
+	for_each_fw_node(card, card->root_node, release_fw_node);
+	KUNIT_EXPECT_EQ(test, data->release_count, 4);
+}
+
+static void node_tree_test_four_nodes_case3(struct kunit *test)
+{
+	//       root
+	// ++============++
+	// ||    phy 3   ||
+	// ||  P0 P1 P2  ||
+	// ++===|==|==|==++
+	//      |  |  +--------------------------------+
+	//      |  +--------------------+              |
+	//      |                       |              |
+	// ++===|==|==x==++  ++===|==|==|==++  ++===|==|==x==++
+	// ||  P0 P1 P2  ||  ||  P0 P1 P2  ||  ||  P0 P1 P2  ||
+	// ||    phy 0   ||  ||    phy 1   ||  ||    phy 2   ||
+	// ++============++  ++============++  ++============++
+	//
+	static const u32 self_id_sequence[] = {
+		0x80000090,
+		0x81000058,
+		0x82000060,
+		0x830000fc,
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x03;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NOT_NULL(test, card->local_node);
+	KUNIT_EXPECT_PTR_EQ(test, card->local_node, card->root_node);
+
+	struct fw_node *node = card->root_node;
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x03);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_NOT_NULL(test, node->ports[2]);
+
+	struct fw_node *parent = node;
+	node = parent->ports[2];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x02);
+	KUNIT_EXPECT_EQ(test, node->port_count, 2);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[1], parent);
+
+	node = parent->ports[1];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x01);
+	KUNIT_EXPECT_EQ(test, node->port_count, 3);
+	KUNIT_EXPECT_NULL(test, node->ports[0]);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[2], parent);
+
+	node = parent->ports[0];
+	KUNIT_EXPECT_EQ(test, node->node_id, LOCAL_BUS | 0x00);
+	KUNIT_EXPECT_EQ(test, node->port_count, 2);
+	KUNIT_EXPECT_PTR_EQ(test, node->ports[0], parent);
+	KUNIT_EXPECT_NULL(test, node->ports[1]);
+
+	++card->color;
+	for_each_fw_node(card, card->root_node, release_fw_node);
+	KUNIT_EXPECT_EQ(test, data->release_count, 4);
+}
+
+static void node_tree_test_invalid_extended_self_id_sequence(struct kunit *test)
+{
+	// Use the same node tree as node_tree_test_four_nodes_case1, except for the invalid
+	// content of self ID packet for the phy 3.
+	static const u32 self_id_sequence[] = {
+		0x80000094,
+		0x81000080,
+		0x820000bc,
+		0x830000d1, // Invalid.
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x03;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NULL(test, card->local_node);
+}
+
+static void node_tree_test_invalid_phy_id(struct kunit *test)
+{
+	// Use the same node tree as node_tree_test_four_nodes_case1, except for the invalid
+	// phy ID for phy 3.
+	static const u32 self_id_sequence[] = {
+		0x80000094,
+		0x81000080,
+		0x820000bc,
+		0x8f0000d0, // Invalid.
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x03;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NULL(test, card->local_node);
+}
+
+static void node_tree_test_invalid_child_port_count(struct kunit *test)
+{
+	// Use the same node tree as node_tree_test_four_nodes_case1, except for the invalid
+	// count of child ports for phy 3.
+	static const u32 self_id_sequence[] = {
+		0x80000094,
+		0x81000080,
+		0x820000bc,
+		0x830000fc, // Invalid.
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x03;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NULL(test, card->local_node);
+}
+
+static void node_tree_test_invalid_parent_port_count(struct kunit *test)
+{
+	// Use the same node tree as node_tree_test_four_nodes_case1, except for the invalid
+	// count of parent ports for phy 3.
+	static const u32 self_id_sequence[] = {
+		0x80000094,
+		0x81000080,
+		0x820000bc,
+		0x830000e8, // Invalid.
+	};
+	struct private_data *data = test->priv;
+	struct fw_card *card = data->card;
+
+	card->node_id = LOCAL_BUS | 0x03;
+
+	card->local_node = build_tree(card, self_id_sequence, ARRAY_SIZE(self_id_sequence), 123);
+	KUNIT_EXPECT_NULL(test, card->local_node);
+}
+
+static struct kunit_case node_tree_test_cases[] = {
+	KUNIT_CASE(node_tree_test_two_nodes),
+	KUNIT_CASE(node_tree_test_two_nodes_1394a),
+	KUNIT_CASE(node_tree_test_three_nodes_case0),
+	KUNIT_CASE(node_tree_test_three_nodes_case1),
+	KUNIT_CASE(node_tree_test_four_nodes_case0),
+	KUNIT_CASE(node_tree_test_four_nodes_case1),
+	KUNIT_CASE(node_tree_test_four_nodes_case2),
+	KUNIT_CASE(node_tree_test_four_nodes_case3),
+	KUNIT_CASE(node_tree_test_invalid_extended_self_id_sequence),
+	KUNIT_CASE(node_tree_test_invalid_phy_id),
+	KUNIT_CASE(node_tree_test_invalid_child_port_count),
+	KUNIT_CASE(node_tree_test_invalid_parent_port_count),
+	{}
+};
+
+static struct kunit_suite node_tree_test_suite = {
+	.name = "firewire-node-tree",
+	.init = node_tree_test_init,
+	.exit = node_tree_test_exit,
+	.test_cases = node_tree_test_cases,
+};
+kunit_test_suite(node_tree_test_suite);