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, 438 insertions, 0 deletions

diff --git a/net/bluetooth/mgmt_util.c b/net/bluetooth/mgmt_util.c
new file mode 100644
index 000000000..6ea107c0e
--- /dev/null
+++ b/net/bluetooth/mgmt_util.c
@@ -0,0 +1,438 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+   BlueZ - Bluetooth protocol stack for Linux
+
+   Copyright (C) 2015  Intel Corporation
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
+   CLAIM, OR ANY SPECIAL 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.
+
+   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
+   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
+   SOFTWARE IS DISCLAIMED.
+*/
+
+#include <linux/unaligned.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <net/bluetooth/hci_mon.h>
+#include <net/bluetooth/mgmt.h>
+
+#include "mgmt_util.h"
+
+static struct sk_buff *create_monitor_ctrl_event(__le16 index, u32 cookie,
+						 u16 opcode, u16 len, void *buf)
+{
+	struct hci_mon_hdr *hdr;
+	struct sk_buff *skb;
+
+	skb = bt_skb_alloc(6 + len, GFP_ATOMIC);
+	if (!skb)
+		return NULL;
+
+	put_unaligned_le32(cookie, skb_put(skb, 4));
+	put_unaligned_le16(opcode, skb_put(skb, 2));
+
+	if (buf)
+		skb_put_data(skb, buf, len);
+
+	__net_timestamp(skb);
+
+	hdr = skb_push(skb, HCI_MON_HDR_SIZE);
+	hdr->opcode = cpu_to_le16(HCI_MON_CTRL_EVENT);
+	hdr->index = index;
+	hdr->len = cpu_to_le16(skb->len - HCI_MON_HDR_SIZE);
+
+	return skb;
+}
+
+struct sk_buff *mgmt_alloc_skb(struct hci_dev *hdev, u16 opcode,
+			       unsigned int size)
+{
+	struct sk_buff *skb;
+
+	skb = alloc_skb(sizeof(struct mgmt_hdr) + size, GFP_KERNEL);
+	if (!skb)
+		return skb;
+
+	skb_reserve(skb, sizeof(struct mgmt_hdr));
+	bt_cb(skb)->mgmt.hdev = hdev;
+	bt_cb(skb)->mgmt.opcode = opcode;
+
+	return skb;
+}
+
+int mgmt_send_event_skb(unsigned short channel, struct sk_buff *skb, int flag,
+			struct sock *skip_sk)
+{
+	struct hci_dev *hdev;
+	struct mgmt_hdr *hdr;
+	int len;
+
+	if (!skb)
+		return -EINVAL;
+
+	len = skb->len;
+	hdev = bt_cb(skb)->mgmt.hdev;
+
+	/* Time stamp */
+	__net_timestamp(skb);
+
+	/* Send just the data, without headers, to the monitor */
+	if (channel == HCI_CHANNEL_CONTROL)
+		hci_send_monitor_ctrl_event(hdev, bt_cb(skb)->mgmt.opcode,
+					    skb->data, skb->len,
+					    skb_get_ktime(skb), flag, skip_sk);
+
+	hdr = skb_push(skb, sizeof(*hdr));
+	hdr->opcode = cpu_to_le16(bt_cb(skb)->mgmt.opcode);
+	if (hdev)
+		hdr->index = cpu_to_le16(hdev->id);
+	else
+		hdr->index = cpu_to_le16(MGMT_INDEX_NONE);
+	hdr->len = cpu_to_le16(len);
+
+	hci_send_to_channel(channel, skb, flag, skip_sk);
+
+	kfree_skb(skb);
+	return 0;
+}
+
+int mgmt_send_event(u16 event, struct hci_dev *hdev, unsigned short channel,
+		    void *data, u16 data_len, int flag, struct sock *skip_sk)
+{
+	struct sk_buff *skb;
+
+	skb = mgmt_alloc_skb(hdev, event, data_len);
+	if (!skb)
+		return -ENOMEM;
+
+	if (data)
+		skb_put_data(skb, data, data_len);
+
+	return mgmt_send_event_skb(channel, skb, flag, skip_sk);
+}
+
+int mgmt_cmd_status(struct sock *sk, u16 index, u16 cmd, u8 status)
+{
+	struct sk_buff *skb, *mskb;
+	struct mgmt_hdr *hdr;
+	struct mgmt_ev_cmd_status *ev;
+	int err;
+
+	BT_DBG("sock %p, index %u, cmd %u, status %u", sk, index, cmd, status);
+
+	skb = alloc_skb(sizeof(*hdr) + sizeof(*ev), GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = skb_put(skb, sizeof(*hdr));
+
+	hdr->opcode = cpu_to_le16(MGMT_EV_CMD_STATUS);
+	hdr->index = cpu_to_le16(index);
+	hdr->len = cpu_to_le16(sizeof(*ev));
+
+	ev = skb_put(skb, sizeof(*ev));
+	ev->status = status;
+	ev->opcode = cpu_to_le16(cmd);
+
+	mskb = create_monitor_ctrl_event(hdr->index, hci_sock_get_cookie(sk),
+					 MGMT_EV_CMD_STATUS, sizeof(*ev), ev);
+	if (mskb)
+		skb->tstamp = mskb->tstamp;
+	else
+		__net_timestamp(skb);
+
+	err = sock_queue_rcv_skb(sk, skb);
+	if (err < 0)
+		kfree_skb(skb);
+
+	if (mskb) {
+		hci_send_to_channel(HCI_CHANNEL_MONITOR, mskb,
+				    HCI_SOCK_TRUSTED, NULL);
+		kfree_skb(mskb);
+	}
+
+	return err;
+}
+
+int mgmt_cmd_complete(struct sock *sk, u16 index, u16 cmd, u8 status,
+		      void *rp, size_t rp_len)
+{
+	struct sk_buff *skb, *mskb;
+	struct mgmt_hdr *hdr;
+	struct mgmt_ev_cmd_complete *ev;
+	int err;
+
+	BT_DBG("sock %p", sk);
+
+	skb = alloc_skb(sizeof(*hdr) + sizeof(*ev) + rp_len, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = skb_put(skb, sizeof(*hdr));
+
+	hdr->opcode = cpu_to_le16(MGMT_EV_CMD_COMPLETE);
+	hdr->index = cpu_to_le16(index);
+	hdr->len = cpu_to_le16(sizeof(*ev) + rp_len);
+
+	ev = skb_put(skb, sizeof(*ev) + rp_len);
+	ev->opcode = cpu_to_le16(cmd);
+	ev->status = status;
+
+	if (rp)
+		memcpy(ev->data, rp, rp_len);
+
+	mskb = create_monitor_ctrl_event(hdr->index, hci_sock_get_cookie(sk),
+					 MGMT_EV_CMD_COMPLETE,
+					 sizeof(*ev) + rp_len, ev);
+	if (mskb)
+		skb->tstamp = mskb->tstamp;
+	else
+		__net_timestamp(skb);
+
+	err = sock_queue_rcv_skb(sk, skb);
+	if (err < 0)
+		kfree_skb(skb);
+
+	if (mskb) {
+		hci_send_to_channel(HCI_CHANNEL_MONITOR, mskb,
+				    HCI_SOCK_TRUSTED, NULL);
+		kfree_skb(mskb);
+	}
+
+	return err;
+}
+
+struct mgmt_pending_cmd *mgmt_pending_find(unsigned short channel, u16 opcode,
+					   struct hci_dev *hdev)
+{
+	struct mgmt_pending_cmd *cmd, *tmp;
+
+	mutex_lock(&hdev->mgmt_pending_lock);
+
+	list_for_each_entry_safe(cmd, tmp, &hdev->mgmt_pending, list) {
+		if (hci_sock_get_channel(cmd->sk) != channel)
+			continue;
+
+		if (cmd->opcode == opcode) {
+			mutex_unlock(&hdev->mgmt_pending_lock);
+			return cmd;
+		}
+	}
+
+	mutex_unlock(&hdev->mgmt_pending_lock);
+
+	return NULL;
+}
+
+void mgmt_pending_foreach(u16 opcode, struct hci_dev *hdev, bool remove,
+			  void (*cb)(struct mgmt_pending_cmd *cmd, void *data),
+			  void *data)
+{
+	struct mgmt_pending_cmd *cmd, *tmp;
+
+	mutex_lock(&hdev->mgmt_pending_lock);
+
+	list_for_each_entry_safe(cmd, tmp, &hdev->mgmt_pending, list) {
+		if (opcode > 0 && cmd->opcode != opcode)
+			continue;
+
+		if (remove)
+			list_del(&cmd->list);
+
+		cb(cmd, data);
+
+		if (remove)
+			mgmt_pending_free(cmd);
+	}
+
+	mutex_unlock(&hdev->mgmt_pending_lock);
+}
+
+struct mgmt_pending_cmd *mgmt_pending_new(struct sock *sk, u16 opcode,
+					  struct hci_dev *hdev,
+					  void *data, u16 len)
+{
+	struct mgmt_pending_cmd *cmd;
+
+	cmd = kzalloc_obj(*cmd);
+	if (!cmd)
+		return NULL;
+
+	cmd->opcode = opcode;
+	cmd->hdev = hdev;
+
+	cmd->param = kmemdup(data, len, GFP_KERNEL);
+	if (!cmd->param) {
+		kfree(cmd);
+		return NULL;
+	}
+
+	cmd->param_len = len;
+
+	cmd->sk = sk;
+	sock_hold(sk);
+
+	return cmd;
+}
+
+struct mgmt_pending_cmd *mgmt_pending_add(struct sock *sk, u16 opcode,
+					  struct hci_dev *hdev,
+					  void *data, u16 len)
+{
+	struct mgmt_pending_cmd *cmd;
+
+	cmd = mgmt_pending_new(sk, opcode, hdev, data, len);
+	if (!cmd)
+		return NULL;
+
+	mutex_lock(&hdev->mgmt_pending_lock);
+	list_add_tail(&cmd->list, &hdev->mgmt_pending);
+	mutex_unlock(&hdev->mgmt_pending_lock);
+
+	return cmd;
+}
+
+void mgmt_pending_free(struct mgmt_pending_cmd *cmd)
+{
+	sock_put(cmd->sk);
+	kfree(cmd->param);
+	kfree(cmd);
+}
+
+void mgmt_pending_remove(struct mgmt_pending_cmd *cmd)
+{
+	mutex_lock(&cmd->hdev->mgmt_pending_lock);
+	list_del(&cmd->list);
+	mutex_unlock(&cmd->hdev->mgmt_pending_lock);
+
+	mgmt_pending_free(cmd);
+}
+
+bool __mgmt_pending_listed(struct hci_dev *hdev, struct mgmt_pending_cmd *cmd)
+{
+	struct mgmt_pending_cmd *tmp;
+
+	lockdep_assert_held(&hdev->mgmt_pending_lock);
+
+	if (!cmd)
+		return false;
+
+	list_for_each_entry(tmp, &hdev->mgmt_pending, list) {
+		if (cmd == tmp)
+			return true;
+	}
+
+	return false;
+}
+
+bool mgmt_pending_listed(struct hci_dev *hdev, struct mgmt_pending_cmd *cmd)
+{
+	bool listed;
+
+	mutex_lock(&hdev->mgmt_pending_lock);
+	listed = __mgmt_pending_listed(hdev, cmd);
+	mutex_unlock(&hdev->mgmt_pending_lock);
+
+	return listed;
+}
+
+bool mgmt_pending_valid(struct hci_dev *hdev, struct mgmt_pending_cmd *cmd)
+{
+	bool listed;
+
+	if (!cmd)
+		return false;
+
+	mutex_lock(&hdev->mgmt_pending_lock);
+
+	listed = __mgmt_pending_listed(hdev, cmd);
+	if (listed)
+		list_del(&cmd->list);
+
+	mutex_unlock(&hdev->mgmt_pending_lock);
+
+	return listed;
+}
+
+void mgmt_mesh_foreach(struct hci_dev *hdev,
+		       void (*cb)(struct mgmt_mesh_tx *mesh_tx, void *data),
+		       void *data, struct sock *sk)
+{
+	struct mgmt_mesh_tx *mesh_tx, *tmp;
+
+	list_for_each_entry_safe(mesh_tx, tmp, &hdev->mesh_pending, list) {
+		if (!sk || mesh_tx->sk == sk)
+			cb(mesh_tx, data);
+	}
+}
+
+struct mgmt_mesh_tx *mgmt_mesh_next(struct hci_dev *hdev, struct sock *sk)
+{
+	struct mgmt_mesh_tx *mesh_tx;
+
+	if (list_empty(&hdev->mesh_pending))
+		return NULL;
+
+	list_for_each_entry(mesh_tx, &hdev->mesh_pending, list) {
+		if (!sk || mesh_tx->sk == sk)
+			return mesh_tx;
+	}
+
+	return NULL;
+}
+
+struct mgmt_mesh_tx *mgmt_mesh_find(struct hci_dev *hdev, u8 handle)
+{
+	struct mgmt_mesh_tx *mesh_tx;
+
+	if (list_empty(&hdev->mesh_pending))
+		return NULL;
+
+	list_for_each_entry(mesh_tx, &hdev->mesh_pending, list) {
+		if (mesh_tx->handle == handle)
+			return mesh_tx;
+	}
+
+	return NULL;
+}
+
+struct mgmt_mesh_tx *mgmt_mesh_add(struct sock *sk, struct hci_dev *hdev,
+				   void *data, u16 len)
+{
+	struct mgmt_mesh_tx *mesh_tx;
+
+	mesh_tx = kzalloc_obj(*mesh_tx);
+	if (!mesh_tx)
+		return NULL;
+
+	hdev->mesh_send_ref++;
+	if (!hdev->mesh_send_ref)
+		hdev->mesh_send_ref++;
+
+	mesh_tx->handle = hdev->mesh_send_ref;
+	mesh_tx->index = hdev->id;
+	memcpy(mesh_tx->param, data, len);
+	mesh_tx->param_len = len;
+	mesh_tx->sk = sk;
+	sock_hold(sk);
+
+	list_add_tail(&mesh_tx->list, &hdev->mesh_pending);
+
+	return mesh_tx;
+}
+
+void mgmt_mesh_remove(struct mgmt_mesh_tx *mesh_tx)
+{
+	list_del(&mesh_tx->list);
+	sock_put(mesh_tx->sk);
+	kfree(mesh_tx);
+}