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, 258 insertions, 0 deletions

diff --git a/sound/soc/sof/sof-client-probes-ipc3.c b/sound/soc/sof/sof-client-probes-ipc3.c
new file mode 100644
index 000000000..a3e382d61
--- /dev/null
+++ b/sound/soc/sof/sof-client-probes-ipc3.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright(c) 2019-2022 Intel Corporation
+//
+// Author: Cezary Rojewski <cezary.rojewski@intel.com>
+//
+// Code moved to this file by:
+//  Jyri Sarha <jyri.sarha@intel.com>
+//
+
+#include <linux/stddef.h>
+#include <sound/soc.h>
+#include <sound/sof/header.h>
+#include "sof-client.h"
+#include "sof-client-probes.h"
+
+struct sof_probe_dma {
+	unsigned int stream_tag;
+	unsigned int dma_buffer_size;
+} __packed;
+
+struct sof_ipc_probe_dma_add_params {
+	struct sof_ipc_cmd_hdr hdr;
+	unsigned int num_elems;
+	struct sof_probe_dma dma[];
+} __packed;
+
+struct sof_ipc_probe_info_params {
+	struct sof_ipc_reply rhdr;
+	unsigned int num_elems;
+	union {
+		DECLARE_FLEX_ARRAY(struct sof_probe_dma, dma);
+		DECLARE_FLEX_ARRAY(struct sof_probe_point_desc, desc);
+	};
+} __packed;
+
+struct sof_ipc_probe_point_add_params {
+	struct sof_ipc_cmd_hdr hdr;
+	unsigned int num_elems;
+	struct sof_probe_point_desc desc[];
+} __packed;
+
+struct sof_ipc_probe_point_remove_params {
+	struct sof_ipc_cmd_hdr hdr;
+	unsigned int num_elems;
+	unsigned int buffer_id[];
+} __packed;
+
+/**
+ * ipc3_probes_init - initialize data probing
+ * @cdev:		SOF client device
+ * @stream_tag:		Extractor stream tag
+ * @buffer_size:	DMA buffer size to set for extractor
+ *
+ * Host chooses whether extraction is supported or not by providing
+ * valid stream tag to DSP. Once specified, stream described by that
+ * tag will be tied to DSP for extraction for the entire lifetime of
+ * probe.
+ *
+ * Probing is initialized only once and each INIT request must be
+ * matched by DEINIT call.
+ */
+static int ipc3_probes_init(struct sof_client_dev *cdev, u32 stream_tag,
+			    size_t buffer_size)
+{
+	struct sof_ipc_probe_dma_add_params *msg;
+	size_t size = struct_size(msg, dma, 1);
+	int ret;
+
+	msg = kmalloc(size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+	msg->hdr.size = size;
+	msg->hdr.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_INIT;
+	msg->num_elems = 1;
+	msg->dma[0].stream_tag = stream_tag;
+	msg->dma[0].dma_buffer_size = buffer_size;
+
+	ret = sof_client_ipc_tx_message_no_reply(cdev, msg);
+	kfree(msg);
+	return ret;
+}
+
+/**
+ * ipc3_probes_deinit - cleanup after data probing
+ * @cdev:		SOF client device
+ *
+ * Host sends DEINIT request to free previously initialized probe
+ * on DSP side once it is no longer needed. DEINIT only when there
+ * are no probes connected and with all injectors detached.
+ */
+static int ipc3_probes_deinit(struct sof_client_dev *cdev)
+{
+	struct sof_ipc_cmd_hdr msg;
+
+	msg.size = sizeof(msg);
+	msg.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_DEINIT;
+
+	return sof_client_ipc_tx_message_no_reply(cdev, &msg);
+}
+
+static int ipc3_probes_info(struct sof_client_dev *cdev, unsigned int cmd,
+			    void **params, size_t *num_params,
+			    enum sof_probe_info_type type)
+{
+	size_t max_msg_size = sof_client_get_ipc_max_payload_size(cdev);
+	struct device *dev = &cdev->auxdev.dev;
+	struct sof_ipc_probe_info_params msg = {{{0}}};
+	struct sof_ipc_probe_info_params *reply;
+	size_t bytes, elem_size, payload_size;
+	int ret;
+
+	*params = NULL;
+	*num_params = 0;
+
+	if (type != PROBES_INFO_ACTIVE_PROBES) {
+		dev_err(dev, "%s: info type %u not supported", __func__, type);
+		return -EOPNOTSUPP;
+	}
+
+	reply = kzalloc(max_msg_size, GFP_KERNEL);
+	if (!reply)
+		return -ENOMEM;
+	msg.rhdr.hdr.size = sizeof(msg);
+	msg.rhdr.hdr.cmd = SOF_IPC_GLB_PROBE | cmd;
+
+	ret = sof_client_ipc_tx_message(cdev, &msg, reply, max_msg_size);
+	if (ret < 0 || reply->rhdr.error < 0)
+		goto exit;
+
+	payload_size = reply->rhdr.hdr.size;
+	if (payload_size < offsetof(struct sof_ipc_probe_info_params, dma)) {
+		ret = -EINVAL;
+		goto exit;
+	}
+
+	if (!reply->num_elems)
+		goto exit;
+
+	if (cmd == SOF_IPC_PROBE_DMA_INFO)
+		elem_size = sizeof(reply->dma[0]);
+	else
+		elem_size = sizeof(reply->desc[0]);
+
+	payload_size -= offsetof(struct sof_ipc_probe_info_params, dma);
+	if (reply->num_elems > payload_size / elem_size) {
+		dev_err(dev, "%s: invalid probe info element count %u\n",
+			__func__, reply->num_elems);
+		ret = -EINVAL;
+		goto exit;
+	}
+
+	bytes = reply->num_elems * elem_size;
+	*params = kmemdup(&reply->dma[0], bytes, GFP_KERNEL);
+	if (!*params) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	*num_params = reply->num_elems;
+
+exit:
+	kfree(reply);
+	return ret;
+}
+
+/**
+ * ipc3_probes_points_info - retrieve list of probe points
+ * @cdev:		SOF client device
+ * @desc:	Returned list of active probes
+ * @num_desc:	Returned count of active probes
+ * @type:	Either PROBES_INFO_ACTIVE_PROBES or PROBES_INFO_AVAILABE_PROBES
+ *
+ * If type is PROBES_INFO_ACTIVE_PROBES, host sends PROBE_POINT_INFO
+ * request to obtain list of active probe points, valid for
+ * disconnection when given probe is no longer required.
+ *
+ * Type PROBES_INFO_AVAILABE_PROBES is not yet supported.
+ */
+static int ipc3_probes_points_info(struct sof_client_dev *cdev,
+				   struct sof_probe_point_desc **desc,
+				   size_t *num_desc,
+				   enum sof_probe_info_type type)
+{
+	return ipc3_probes_info(cdev, SOF_IPC_PROBE_POINT_INFO,
+				(void **)desc, num_desc, type);
+}
+
+/**
+ * ipc3_probes_points_add - connect specified probes
+ * @cdev:		SOF client device
+ * @desc:	List of probe points to connect
+ * @num_desc:	Number of elements in @desc
+ *
+ * Dynamically connects to provided set of endpoints. Immediately
+ * after connection is established, host must be prepared to
+ * transfer data from or to target stream given the probing purpose.
+ *
+ * Each probe point should be removed using PROBE_POINT_REMOVE
+ * request when no longer needed.
+ */
+static int ipc3_probes_points_add(struct sof_client_dev *cdev,
+				  struct sof_probe_point_desc *desc,
+				  size_t num_desc)
+{
+	struct sof_ipc_probe_point_add_params *msg;
+	size_t size = struct_size(msg, desc, num_desc);
+	int ret;
+
+	msg = kmalloc(size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+	msg->hdr.size = size;
+	msg->num_elems = num_desc;
+	msg->hdr.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_POINT_ADD;
+	memcpy(&msg->desc[0], desc, size - sizeof(*msg));
+
+	ret = sof_client_ipc_tx_message_no_reply(cdev, msg);
+	kfree(msg);
+	return ret;
+}
+
+/**
+ * ipc3_probes_points_remove - disconnect specified probes
+ * @cdev:		SOF client device
+ * @buffer_id:		List of probe points to disconnect
+ * @num_buffer_id:	Number of elements in @desc
+ *
+ * Removes previously connected probes from list of active probe
+ * points and frees all resources on DSP side.
+ */
+static int ipc3_probes_points_remove(struct sof_client_dev *cdev,
+				     unsigned int *buffer_id,
+				     size_t num_buffer_id)
+{
+	struct sof_ipc_probe_point_remove_params *msg;
+	size_t size = struct_size(msg, buffer_id, num_buffer_id);
+	int ret;
+
+	msg = kmalloc(size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+	msg->hdr.size = size;
+	msg->num_elems = num_buffer_id;
+	msg->hdr.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_POINT_REMOVE;
+	memcpy(&msg->buffer_id[0], buffer_id, size - sizeof(*msg));
+
+	ret = sof_client_ipc_tx_message_no_reply(cdev, msg);
+	kfree(msg);
+	return ret;
+}
+
+const struct sof_probes_ipc_ops ipc3_probe_ops =  {
+	.init = ipc3_probes_init,
+	.deinit = ipc3_probes_deinit,
+	.points_info = ipc3_probes_points_info,
+	.points_add = ipc3_probes_points_add,
+	.points_remove = ipc3_probes_points_remove,
+};