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, 253 insertions, 0 deletions

diff --git a/net/bluetooth/hci_codec.c b/net/bluetooth/hci_codec.c
new file mode 100644
index 000000000..5bc5003c3
--- /dev/null
+++ b/net/bluetooth/hci_codec.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (C) 2021 Intel Corporation */
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include "hci_codec.h"
+
+static int hci_codec_list_add(struct list_head *list,
+			      struct hci_op_read_local_codec_caps *sent,
+			      struct hci_rp_read_local_codec_caps *rp,
+			      void *caps,
+			      __u32 len)
+{
+	struct codec_list *entry;
+
+	entry = kzalloc(sizeof(*entry) + len, GFP_KERNEL);
+	if (!entry)
+		return -ENOMEM;
+
+	entry->id = sent->id;
+	if (sent->id == 0xFF) {
+		entry->cid = __le16_to_cpu(sent->cid);
+		entry->vid = __le16_to_cpu(sent->vid);
+	}
+	entry->transport = sent->transport;
+	entry->len = len;
+	entry->num_caps = 0;
+	if (rp) {
+		entry->num_caps = rp->num_caps;
+		memcpy(entry->caps, caps, len);
+	}
+	list_add(&entry->list, list);
+
+	return 0;
+}
+
+void hci_codec_list_clear(struct list_head *codec_list)
+{
+	struct codec_list *c, *n;
+
+	list_for_each_entry_safe(c, n, codec_list, list) {
+		list_del(&c->list);
+		kfree(c);
+	}
+}
+
+static void hci_read_codec_capabilities(struct hci_dev *hdev, __u8 transport,
+					struct hci_op_read_local_codec_caps
+					*cmd)
+{
+	__u8 i;
+
+	for (i = 0; i < TRANSPORT_TYPE_MAX; i++) {
+		if (transport & BIT(i)) {
+			struct hci_rp_read_local_codec_caps *rp;
+			struct hci_codec_caps *caps;
+			struct sk_buff *skb;
+			__u8 j;
+			__u32 len;
+
+			cmd->transport = i;
+
+			/* If Read_Codec_Capabilities command is not supported
+			 * then just add codec to the list without caps
+			 */
+			if (!(hdev->commands[45] & 0x08)) {
+				hci_dev_lock(hdev);
+				hci_codec_list_add(&hdev->local_codecs, cmd,
+						   NULL, NULL, 0);
+				hci_dev_unlock(hdev);
+				continue;
+			}
+
+			skb = __hci_cmd_sync_sk(hdev, HCI_OP_READ_LOCAL_CODEC_CAPS,
+						sizeof(*cmd), cmd, 0, HCI_CMD_TIMEOUT, NULL);
+			if (IS_ERR(skb)) {
+				bt_dev_err(hdev, "Failed to read codec capabilities (%ld)",
+					   PTR_ERR(skb));
+				continue;
+			}
+
+			if (skb->len < sizeof(*rp))
+				goto error;
+
+			rp = (void *)skb->data;
+
+			if (rp->status)
+				goto error;
+
+			if (!rp->num_caps) {
+				len = 0;
+				/* this codec doesn't have capabilities */
+				goto skip_caps_parse;
+			}
+
+			skb_pull(skb, sizeof(*rp));
+
+			for (j = 0, len = 0; j < rp->num_caps; j++) {
+				caps = (void *)skb->data;
+				if (skb->len < sizeof(*caps))
+					goto error;
+				if (skb->len < sizeof(caps->len) + caps->len)
+					goto error;
+				len += sizeof(caps->len) + caps->len;
+				skb_pull(skb,  sizeof(caps->len) + caps->len);
+			}
+
+skip_caps_parse:
+			hci_dev_lock(hdev);
+			hci_codec_list_add(&hdev->local_codecs, cmd, rp,
+					   (__u8 *)rp + sizeof(*rp), len);
+			hci_dev_unlock(hdev);
+error:
+			kfree_skb(skb);
+		}
+	}
+}
+
+void hci_read_supported_codecs(struct hci_dev *hdev)
+{
+	struct sk_buff *skb;
+	struct hci_rp_read_local_supported_codecs *rp;
+	struct hci_std_codecs *std_codecs;
+	struct hci_vnd_codecs *vnd_codecs;
+	struct hci_op_read_local_codec_caps caps;
+	__u8 i;
+
+	skb = __hci_cmd_sync_sk(hdev, HCI_OP_READ_LOCAL_CODECS, 0, NULL,
+				0, HCI_CMD_TIMEOUT, NULL);
+
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "Failed to read local supported codecs (%ld)",
+			   PTR_ERR(skb));
+		return;
+	}
+
+	if (skb->len < sizeof(*rp))
+		goto error;
+
+	rp = (void *)skb->data;
+
+	if (rp->status)
+		goto error;
+
+	skb_pull(skb, sizeof(rp->status));
+
+	std_codecs = (void *)skb->data;
+
+	/* validate codecs length before accessing */
+	if (skb->len < flex_array_size(std_codecs, codec, std_codecs->num)
+	    + sizeof(std_codecs->num))
+		goto error;
+
+	/* enumerate codec capabilities of standard codecs */
+	memset(&caps, 0, sizeof(caps));
+	for (i = 0; i < std_codecs->num; i++) {
+		caps.id = std_codecs->codec[i];
+		caps.direction = 0x00;
+		hci_read_codec_capabilities(hdev,
+					    LOCAL_CODEC_ACL_MASK | LOCAL_CODEC_SCO_MASK, &caps);
+	}
+
+	skb_pull(skb, flex_array_size(std_codecs, codec, std_codecs->num)
+		 + sizeof(std_codecs->num));
+
+	vnd_codecs = (void *)skb->data;
+
+	/* validate vendor codecs length before accessing */
+	if (skb->len <
+	    flex_array_size(vnd_codecs, codec, vnd_codecs->num)
+	    + sizeof(vnd_codecs->num))
+		goto error;
+
+	/* enumerate vendor codec capabilities */
+	for (i = 0; i < vnd_codecs->num; i++) {
+		caps.id = 0xFF;
+		caps.cid = vnd_codecs->codec[i].cid;
+		caps.vid = vnd_codecs->codec[i].vid;
+		caps.direction = 0x00;
+		hci_read_codec_capabilities(hdev,
+					    LOCAL_CODEC_ACL_MASK | LOCAL_CODEC_SCO_MASK, &caps);
+	}
+
+error:
+	kfree_skb(skb);
+}
+
+void hci_read_supported_codecs_v2(struct hci_dev *hdev)
+{
+	struct sk_buff *skb;
+	struct hci_rp_read_local_supported_codecs_v2 *rp;
+	struct hci_std_codecs_v2 *std_codecs;
+	struct hci_vnd_codecs_v2 *vnd_codecs;
+	struct hci_op_read_local_codec_caps caps;
+	__u8 i;
+
+	skb = __hci_cmd_sync_sk(hdev, HCI_OP_READ_LOCAL_CODECS_V2, 0, NULL,
+				0, HCI_CMD_TIMEOUT, NULL);
+
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "Failed to read local supported codecs (%ld)",
+			   PTR_ERR(skb));
+		return;
+	}
+
+	if (skb->len < sizeof(*rp))
+		goto error;
+
+	rp = (void *)skb->data;
+
+	if (rp->status)
+		goto error;
+
+	skb_pull(skb, sizeof(rp->status));
+
+	std_codecs = (void *)skb->data;
+
+	/* check for payload data length before accessing */
+	if (skb->len < flex_array_size(std_codecs, codec, std_codecs->num)
+	    + sizeof(std_codecs->num))
+		goto error;
+
+	memset(&caps, 0, sizeof(caps));
+
+	for (i = 0; i < std_codecs->num; i++) {
+		caps.id = std_codecs->codec[i].id;
+		hci_read_codec_capabilities(hdev, std_codecs->codec[i].transport,
+					    &caps);
+	}
+
+	skb_pull(skb, flex_array_size(std_codecs, codec, std_codecs->num)
+		 + sizeof(std_codecs->num));
+
+	vnd_codecs = (void *)skb->data;
+
+	/* check for payload data length before accessing */
+	if (skb->len <
+	    flex_array_size(vnd_codecs, codec, vnd_codecs->num)
+	    + sizeof(vnd_codecs->num))
+		goto error;
+
+	for (i = 0; i < vnd_codecs->num; i++) {
+		caps.id = 0xFF;
+		caps.cid = vnd_codecs->codec[i].cid;
+		caps.vid = vnd_codecs->codec[i].vid;
+		hci_read_codec_capabilities(hdev, vnd_codecs->codec[i].transport,
+					    &caps);
+	}
+
+error:
+	kfree_skb(skb);
+}