x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 657 insertions, 0 deletions

diff --git a/sound/soc/sof/sof-client.c b/sound/soc/sof/sof-client.c
new file mode 100644
index 000000000..64da8df15
--- /dev/null
+++ b/sound/soc/sof/sof-client.c
@@ -0,0 +1,657 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright(c) 2022 Intel Corporation
+//
+// Authors: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
+//	    Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
+//
+
+#include <linux/debugfs.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <sound/sof/ipc4/header.h>
+#include "ops.h"
+#include "sof-client.h"
+#include "sof-priv.h"
+#include "ipc3-priv.h"
+#include "ipc4-priv.h"
+
+/**
+ * struct sof_ipc_event_entry - IPC client event description
+ * @ipc_msg_type:	IPC msg type of the event the client is interested
+ * @cdev:		sof_client_dev of the requesting client
+ * @callback:		Callback function of the client
+ * @list:		item in SOF core client event list
+ */
+struct sof_ipc_event_entry {
+	u32 ipc_msg_type;
+	struct sof_client_dev *cdev;
+	sof_client_event_callback callback;
+	struct list_head list;
+};
+
+/**
+ * struct sof_state_event_entry - DSP panic event subscription entry
+ * @cdev:		sof_client_dev of the requesting client
+ * @callback:		Callback function of the client
+ * @list:		item in SOF core client event list
+ */
+struct sof_state_event_entry {
+	struct sof_client_dev *cdev;
+	sof_client_fw_state_callback callback;
+	struct list_head list;
+};
+
+/**
+ * struct sof_client_dev_entry - client device entry for internal management use
+ * @sdev:	pointer to SOF core device struct
+ * @list:	item in SOF core client dev list
+ * @client_dev: SOF client device
+ */
+struct sof_client_dev_entry {
+	struct snd_sof_dev *sdev;
+	struct list_head list;
+
+	struct sof_client_dev client_dev;
+};
+
+#define cdev_to_centry(cdev) \
+	container_of(cdev, struct sof_client_dev_entry, client_dev)
+
+static void sof_client_auxdev_release(struct device *dev)
+{
+	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
+	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
+	struct sof_client_dev_entry *centry = cdev_to_centry(cdev);
+
+	kfree(cdev->auxdev.dev.platform_data);
+	kfree(centry);
+}
+
+static int sof_client_dev_add_data(struct sof_client_dev *cdev, const void *data,
+				   size_t size)
+{
+	void *d = NULL;
+
+	if (data) {
+		d = kmemdup(data, size, GFP_KERNEL);
+		if (!d)
+			return -ENOMEM;
+	}
+
+	cdev->auxdev.dev.platform_data = d;
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST)
+static int sof_register_ipc_flood_test(struct snd_sof_dev *sdev)
+{
+	int ret = 0;
+	int i;
+
+	if (sdev->pdata->ipc_type != SOF_IPC_TYPE_3)
+		return 0;
+
+	for (i = 0; i < CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST_NUM; i++) {
+		ret = sof_client_dev_register(sdev, "ipc_flood", i, NULL, 0);
+		if (ret < 0)
+			break;
+	}
+
+	if (ret) {
+		for (; i >= 0; --i)
+			sof_client_dev_unregister(sdev, "ipc_flood", i);
+	}
+
+	return ret;
+}
+
+static void sof_unregister_ipc_flood_test(struct snd_sof_dev *sdev)
+{
+	int i;
+
+	for (i = 0; i < CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST_NUM; i++)
+		sof_client_dev_unregister(sdev, "ipc_flood", i);
+}
+#else
+static inline int sof_register_ipc_flood_test(struct snd_sof_dev *sdev)
+{
+	return 0;
+}
+
+static inline void sof_unregister_ipc_flood_test(struct snd_sof_dev *sdev) {}
+#endif /* CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST */
+
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_MSG_INJECTOR)
+static int sof_register_ipc_msg_injector(struct snd_sof_dev *sdev)
+{
+	return sof_client_dev_register(sdev, "msg_injector", 0, NULL, 0);
+}
+
+static void sof_unregister_ipc_msg_injector(struct snd_sof_dev *sdev)
+{
+	sof_client_dev_unregister(sdev, "msg_injector", 0);
+}
+#else
+static inline int sof_register_ipc_msg_injector(struct snd_sof_dev *sdev)
+{
+	return 0;
+}
+
+static inline void sof_unregister_ipc_msg_injector(struct snd_sof_dev *sdev) {}
+#endif /* CONFIG_SND_SOC_SOF_DEBUG_IPC_MSG_INJECTOR */
+
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_KERNEL_INJECTOR)
+static int sof_register_ipc_kernel_injector(struct snd_sof_dev *sdev)
+{
+	/* Only IPC3 supported right now */
+	if (sdev->pdata->ipc_type != SOF_IPC_TYPE_3)
+		return 0;
+
+	return sof_client_dev_register(sdev, "kernel_injector", 0, NULL, 0);
+}
+
+static void sof_unregister_ipc_kernel_injector(struct snd_sof_dev *sdev)
+{
+	sof_client_dev_unregister(sdev, "kernel_injector", 0);
+}
+#else
+static inline int sof_register_ipc_kernel_injector(struct snd_sof_dev *sdev)
+{
+	return 0;
+}
+
+static inline void sof_unregister_ipc_kernel_injector(struct snd_sof_dev *sdev) {}
+#endif /* CONFIG_SND_SOC_SOF_DEBUG_IPC_KERNEL_INJECTOR */
+
+int sof_register_clients(struct snd_sof_dev *sdev)
+{
+	int ret;
+
+	if (sdev->dspless_mode_selected)
+		return 0;
+
+	/* Register platform independent client devices */
+	ret = sof_register_ipc_flood_test(sdev);
+	if (ret) {
+		dev_err(sdev->dev, "IPC flood test client registration failed\n");
+		return ret;
+	}
+
+	ret = sof_register_ipc_msg_injector(sdev);
+	if (ret) {
+		dev_err(sdev->dev, "IPC message injector client registration failed\n");
+		goto err_msg_injector;
+	}
+
+	ret = sof_register_ipc_kernel_injector(sdev);
+	if (ret) {
+		dev_err(sdev->dev, "IPC kernel injector client registration failed\n");
+		goto err_kernel_injector;
+	}
+
+	/* Platform dependent client device registration */
+
+	if (sof_ops(sdev) && sof_ops(sdev)->register_ipc_clients)
+		ret = sof_ops(sdev)->register_ipc_clients(sdev);
+
+	if (!ret)
+		return 0;
+
+	sof_unregister_ipc_kernel_injector(sdev);
+
+err_kernel_injector:
+	sof_unregister_ipc_msg_injector(sdev);
+
+err_msg_injector:
+	sof_unregister_ipc_flood_test(sdev);
+
+	return ret;
+}
+
+void sof_unregister_clients(struct snd_sof_dev *sdev)
+{
+	if (sof_ops(sdev) && sof_ops(sdev)->unregister_ipc_clients)
+		sof_ops(sdev)->unregister_ipc_clients(sdev);
+
+	sof_unregister_ipc_kernel_injector(sdev);
+	sof_unregister_ipc_msg_injector(sdev);
+	sof_unregister_ipc_flood_test(sdev);
+}
+
+int sof_client_dev_register(struct snd_sof_dev *sdev, const char *name, u32 id,
+			    const void *data, size_t size)
+{
+	struct sof_client_dev_entry *centry;
+	struct auxiliary_device *auxdev;
+	struct sof_client_dev *cdev;
+	int ret;
+
+	centry = kzalloc_obj(*centry);
+	if (!centry)
+		return -ENOMEM;
+
+	cdev = &centry->client_dev;
+
+	centry->sdev = sdev;
+	auxdev = &cdev->auxdev;
+	auxdev->name = name;
+	auxdev->dev.parent = sdev->dev;
+	auxdev->dev.release = sof_client_auxdev_release;
+	auxdev->id = id;
+
+	ret = sof_client_dev_add_data(cdev, data, size);
+	if (ret < 0)
+		goto err_dev_add_data;
+
+	ret = auxiliary_device_init(auxdev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "failed to initialize client dev %s.%d\n", name, id);
+		goto err_dev_init;
+	}
+
+	ret = auxiliary_device_add(&cdev->auxdev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "failed to add client dev %s.%d\n", name, id);
+		/*
+		 * sof_client_auxdev_release() will be invoked to free up memory
+		 * allocations through put_device()
+		 */
+		auxiliary_device_uninit(&cdev->auxdev);
+		return ret;
+	}
+
+	/* add to list of SOF client devices */
+	scoped_guard(mutex, &sdev->ipc_client_mutex)
+		list_add(&centry->list, &sdev->ipc_client_list);
+
+	return 0;
+
+err_dev_init:
+	kfree(cdev->auxdev.dev.platform_data);
+
+err_dev_add_data:
+	kfree(centry);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_dev_register, "SND_SOC_SOF_CLIENT");
+
+void sof_client_dev_unregister(struct snd_sof_dev *sdev, const char *name, u32 id)
+{
+	struct sof_client_dev_entry *centry;
+
+	guard(mutex)(&sdev->ipc_client_mutex);
+
+	/*
+	 * sof_client_auxdev_release() will be invoked to free up memory
+	 * allocations through put_device()
+	 */
+	list_for_each_entry(centry, &sdev->ipc_client_list, list) {
+		struct sof_client_dev *cdev = &centry->client_dev;
+
+		if (!strcmp(cdev->auxdev.name, name) && cdev->auxdev.id == id) {
+			list_del(&centry->list);
+			auxiliary_device_delete(&cdev->auxdev);
+			auxiliary_device_uninit(&cdev->auxdev);
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_dev_unregister, "SND_SOC_SOF_CLIENT");
+
+int sof_client_ipc_tx_message(struct sof_client_dev *cdev, void *ipc_msg,
+			      void *reply_data, size_t reply_bytes)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	if (sdev->pdata->ipc_type == SOF_IPC_TYPE_3) {
+		struct sof_ipc_cmd_hdr *hdr = ipc_msg;
+
+		return sof_ipc_tx_message(sdev->ipc, ipc_msg, hdr->size,
+					  reply_data, reply_bytes);
+	} else if (sdev->pdata->ipc_type == SOF_IPC_TYPE_4) {
+		struct sof_ipc4_msg *msg = ipc_msg;
+
+		return sof_ipc_tx_message(sdev->ipc, ipc_msg, msg->data_size,
+					  reply_data, reply_bytes);
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_ipc_tx_message, "SND_SOC_SOF_CLIENT");
+
+int sof_client_ipc_rx_message(struct sof_client_dev *cdev, void *ipc_msg, void *msg_buf)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	if (IS_ENABLED(CONFIG_SND_SOC_SOF_IPC3) &&
+	    sdev->pdata->ipc_type == SOF_IPC_TYPE_3) {
+		struct sof_ipc_cmd_hdr *hdr = ipc_msg;
+
+		if (hdr->size < sizeof(hdr)) {
+			dev_err(sdev->dev, "The received message size is invalid\n");
+			return -EINVAL;
+		}
+
+		sof_ipc3_do_rx_work(sdev, ipc_msg, msg_buf);
+		return 0;
+	}
+
+	return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_ipc_rx_message, "SND_SOC_SOF_CLIENT");
+
+int sof_client_ipc_set_get_data(struct sof_client_dev *cdev, void *ipc_msg,
+				bool set)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	if (sdev->pdata->ipc_type == SOF_IPC_TYPE_3) {
+		struct sof_ipc_cmd_hdr *hdr = ipc_msg;
+
+		return sof_ipc_set_get_data(sdev->ipc, ipc_msg, hdr->size, set);
+	} else if (sdev->pdata->ipc_type == SOF_IPC_TYPE_4) {
+		struct sof_ipc4_msg *msg = ipc_msg;
+
+		return sof_ipc_set_get_data(sdev->ipc, ipc_msg, msg->data_size,
+					    set);
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_ipc_set_get_data, "SND_SOC_SOF_CLIENT");
+
+#ifdef CONFIG_SND_SOC_SOF_IPC4
+struct sof_ipc4_fw_module *sof_client_ipc4_find_module(struct sof_client_dev *c, const guid_t *uuid)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(c);
+
+	if (sdev->pdata->ipc_type == SOF_IPC_TYPE_4)
+		return sof_ipc4_find_module_by_uuid(sdev, uuid);
+	dev_err(sdev->dev, "Only supported with IPC4\n");
+
+	return NULL;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_ipc4_find_module, "SND_SOC_SOF_CLIENT");
+
+struct snd_sof_widget *sof_client_ipc4_find_swidget_by_id(struct sof_client_dev *cdev,
+							  u32 module_id, int instance_id)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	if (sdev->pdata->ipc_type == SOF_IPC_TYPE_4)
+		return sof_ipc4_find_swidget_by_ids(sdev, module_id, instance_id);
+	dev_err(sdev->dev, "Only supported with IPC4\n");
+
+	return NULL;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_ipc4_find_swidget_by_id, "SND_SOC_SOF_CLIENT");
+#endif
+
+int sof_suspend_clients(struct snd_sof_dev *sdev, pm_message_t state)
+{
+	const struct auxiliary_driver *adrv;
+	struct sof_client_dev_entry *centry;
+
+	guard(mutex)(&sdev->ipc_client_mutex);
+
+	list_for_each_entry(centry, &sdev->ipc_client_list, list) {
+		struct sof_client_dev *cdev = &centry->client_dev;
+
+		/* Skip devices without loaded driver */
+		if (!cdev->auxdev.dev.driver)
+			continue;
+
+		adrv = to_auxiliary_drv(cdev->auxdev.dev.driver);
+		if (adrv->suspend)
+			adrv->suspend(&cdev->auxdev, state);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(sof_suspend_clients, "SND_SOC_SOF_CLIENT");
+
+int sof_resume_clients(struct snd_sof_dev *sdev)
+{
+	const struct auxiliary_driver *adrv;
+	struct sof_client_dev_entry *centry;
+
+	guard(mutex)(&sdev->ipc_client_mutex);
+
+	list_for_each_entry(centry, &sdev->ipc_client_list, list) {
+		struct sof_client_dev *cdev = &centry->client_dev;
+
+		/* Skip devices without loaded driver */
+		if (!cdev->auxdev.dev.driver)
+			continue;
+
+		adrv = to_auxiliary_drv(cdev->auxdev.dev.driver);
+		if (adrv->resume)
+			adrv->resume(&cdev->auxdev);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(sof_resume_clients, "SND_SOC_SOF_CLIENT");
+
+struct dentry *sof_client_get_debugfs_root(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	return sdev->debugfs_root;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_debugfs_root, "SND_SOC_SOF_CLIENT");
+
+/* DMA buffer allocation in client drivers must use the core SOF device */
+struct device *sof_client_get_dma_dev(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	return sdev->dev;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_dma_dev, "SND_SOC_SOF_CLIENT");
+
+const struct sof_ipc_fw_version *sof_client_get_fw_version(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	return &sdev->fw_ready.version;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_fw_version, "SND_SOC_SOF_CLIENT");
+
+size_t sof_client_get_ipc_max_payload_size(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	return sdev->ipc->max_payload_size;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_ipc_max_payload_size, "SND_SOC_SOF_CLIENT");
+
+enum sof_ipc_type sof_client_get_ipc_type(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	return sdev->pdata->ipc_type;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_ipc_type, "SND_SOC_SOF_CLIENT");
+
+int sof_client_boot_dsp(struct sof_client_dev *cdev)
+{
+	return snd_sof_boot_dsp_firmware(sof_client_dev_to_sof_dev(cdev));
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_boot_dsp, "SND_SOC_SOF_CLIENT");
+
+/* module refcount management of SOF core */
+int sof_client_core_module_get(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	if (!try_module_get(sdev->dev->driver->owner))
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_core_module_get, "SND_SOC_SOF_CLIENT");
+
+void sof_client_core_module_put(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	module_put(sdev->dev->driver->owner);
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_core_module_put, "SND_SOC_SOF_CLIENT");
+
+/* IPC event handling */
+void sof_client_ipc_rx_dispatcher(struct snd_sof_dev *sdev, void *msg_buf)
+{
+	struct sof_ipc_event_entry *event;
+	u32 msg_type;
+
+	if (sdev->pdata->ipc_type == SOF_IPC_TYPE_3) {
+		struct sof_ipc_cmd_hdr *hdr = msg_buf;
+
+		msg_type = hdr->cmd & SOF_GLB_TYPE_MASK;
+	} else if (sdev->pdata->ipc_type == SOF_IPC_TYPE_4) {
+		struct sof_ipc4_msg *msg = msg_buf;
+
+		msg_type = SOF_IPC4_NOTIFICATION_TYPE_GET(msg->primary);
+	} else {
+		dev_dbg_once(sdev->dev, "Not supported IPC version: %d\n",
+			     sdev->pdata->ipc_type);
+		return;
+	}
+
+	guard(mutex)(&sdev->client_event_handler_mutex);
+	list_for_each_entry(event, &sdev->ipc_rx_handler_list, list) {
+		if (event->ipc_msg_type == msg_type)
+			event->callback(event->cdev, msg_buf);
+	}
+}
+
+int sof_client_register_ipc_rx_handler(struct sof_client_dev *cdev,
+				       u32 ipc_msg_type,
+				       sof_client_event_callback callback)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+	struct sof_ipc_event_entry *event;
+
+	if (!callback)
+		return -EINVAL;
+
+	if (sdev->pdata->ipc_type == SOF_IPC_TYPE_3) {
+		if (!(ipc_msg_type & SOF_GLB_TYPE_MASK))
+			return -EINVAL;
+	} else if (sdev->pdata->ipc_type == SOF_IPC_TYPE_4) {
+		if (!(ipc_msg_type & SOF_IPC4_NOTIFICATION_TYPE_MASK))
+			return -EINVAL;
+	} else {
+		dev_warn(sdev->dev, "%s: Not supported IPC version: %d\n",
+			 __func__, sdev->pdata->ipc_type);
+		return -EINVAL;
+	}
+
+	event = kmalloc_obj(*event);
+	if (!event)
+		return -ENOMEM;
+
+	event->ipc_msg_type = ipc_msg_type;
+	event->cdev = cdev;
+	event->callback = callback;
+
+	/* add to list of SOF client devices */
+	guard(mutex)(&sdev->client_event_handler_mutex);
+	list_add(&event->list, &sdev->ipc_rx_handler_list);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_register_ipc_rx_handler, "SND_SOC_SOF_CLIENT");
+
+void sof_client_unregister_ipc_rx_handler(struct sof_client_dev *cdev,
+					  u32 ipc_msg_type)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+	struct sof_ipc_event_entry *event;
+
+	guard(mutex)(&sdev->ipc_client_mutex);
+
+	list_for_each_entry(event, &sdev->ipc_rx_handler_list, list) {
+		if (event->cdev == cdev && event->ipc_msg_type == ipc_msg_type) {
+			list_del(&event->list);
+			kfree(event);
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_unregister_ipc_rx_handler, "SND_SOC_SOF_CLIENT");
+
+/*DSP state notification and query */
+void sof_client_fw_state_dispatcher(struct snd_sof_dev *sdev)
+{
+	struct sof_state_event_entry *event;
+
+	guard(mutex)(&sdev->ipc_client_mutex);
+
+	list_for_each_entry(event, &sdev->fw_state_handler_list, list)
+		event->callback(event->cdev, sdev->fw_state);
+}
+
+int sof_client_register_fw_state_handler(struct sof_client_dev *cdev,
+					 sof_client_fw_state_callback callback)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+	struct sof_state_event_entry *event;
+
+	if (!callback)
+		return -EINVAL;
+
+	event = kmalloc_obj(*event);
+	if (!event)
+		return -ENOMEM;
+
+	event->cdev = cdev;
+	event->callback = callback;
+
+	/* add to list of SOF client devices */
+	guard(mutex)(&sdev->client_event_handler_mutex);
+	list_add(&event->list, &sdev->fw_state_handler_list);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_register_fw_state_handler, "SND_SOC_SOF_CLIENT");
+
+void sof_client_unregister_fw_state_handler(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+	struct sof_state_event_entry *event;
+
+	guard(mutex)(&sdev->ipc_client_mutex);
+
+	list_for_each_entry(event, &sdev->fw_state_handler_list, list) {
+		if (event->cdev == cdev) {
+			list_del(&event->list);
+			kfree(event);
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_unregister_fw_state_handler, "SND_SOC_SOF_CLIENT");
+
+enum sof_fw_state sof_client_get_fw_state(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	return sdev->fw_state;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_fw_state, "SND_SOC_SOF_CLIENT");
+
+struct snd_sof_dev *sof_client_dev_to_sof_dev(struct sof_client_dev *cdev)
+{
+	struct sof_client_dev_entry *centry = cdev_to_centry(cdev);
+
+	return centry->sdev;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_dev_to_sof_dev, "SND_SOC_SOF_CLIENT");