Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 742 insertions, 0 deletions

diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c
new file mode 100644
index 000000000..6579bd19d
--- /dev/null
+++ b/drivers/hid/hid-hyperv.c
@@ -0,0 +1,742 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Copyright (c) 2009, Citrix Systems, Inc.
+ *  Copyright (c) 2010, Microsoft Corporation.
+ *  Copyright (c) 2011, Novell Inc.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/completion.h>
+#include <linux/input.h>
+#include <linux/hid.h>
+#include <linux/hiddev.h>
+#include <linux/hyperv.h>
+
+#if IS_ENABLED(CONFIG_HID_HYPERV_MOUSE_KUNIT_TEST)
+#include <kunit/test.h>
+#endif
+
+struct hv_input_dev_info {
+	unsigned int size;
+	unsigned short vendor;
+	unsigned short product;
+	unsigned short version;
+	unsigned short reserved[11];
+};
+
+/*
+ * Current version
+ *
+ * History:
+ * Beta, RC < 2008/1/22        1,0
+ * RC > 2008/1/22              2,0
+ */
+#define SYNTHHID_INPUT_VERSION_MAJOR	2
+#define SYNTHHID_INPUT_VERSION_MINOR	0
+#define SYNTHHID_INPUT_VERSION		(SYNTHHID_INPUT_VERSION_MINOR | \
+					 (SYNTHHID_INPUT_VERSION_MAJOR << 16))
+
+
+#pragma pack(push, 1)
+/*
+ * Message types in the synthetic input protocol
+ */
+enum synthhid_msg_type {
+	SYNTH_HID_PROTOCOL_REQUEST,
+	SYNTH_HID_PROTOCOL_RESPONSE,
+	SYNTH_HID_INITIAL_DEVICE_INFO,
+	SYNTH_HID_INITIAL_DEVICE_INFO_ACK,
+	SYNTH_HID_INPUT_REPORT,
+	SYNTH_HID_MAX
+};
+
+/*
+ * Basic message structures.
+ */
+struct synthhid_msg_hdr {
+	enum synthhid_msg_type type;
+	u32 size;
+};
+
+union synthhid_version {
+	struct {
+		u16 minor_version;
+		u16 major_version;
+	};
+	u32 version;
+};
+
+/*
+ * Protocol messages
+ */
+struct synthhid_protocol_request {
+	struct synthhid_msg_hdr header;
+	union synthhid_version version_requested;
+};
+
+struct synthhid_protocol_response {
+	struct synthhid_msg_hdr header;
+	union synthhid_version version_requested;
+	unsigned char approved;
+};
+
+struct synthhid_device_info {
+	struct synthhid_msg_hdr header;
+	struct hv_input_dev_info hid_dev_info;
+	struct hid_descriptor hid_descriptor;
+};
+
+struct synthhid_device_info_ack {
+	struct synthhid_msg_hdr header;
+	unsigned char reserved;
+};
+
+struct synthhid_input_report {
+	struct synthhid_msg_hdr header;
+	char buffer[];
+};
+
+#pragma pack(pop)
+
+#define INPUTVSC_SEND_RING_BUFFER_SIZE	VMBUS_RING_SIZE(36 * 1024)
+#define INPUTVSC_RECV_RING_BUFFER_SIZE	VMBUS_RING_SIZE(36 * 1024)
+
+
+enum pipe_prot_msg_type {
+	PIPE_MESSAGE_INVALID,
+	PIPE_MESSAGE_DATA,
+	PIPE_MESSAGE_MAXIMUM
+};
+
+
+struct pipe_prt_msg {
+	enum pipe_prot_msg_type type;
+	u32 size;
+	char data[];
+};
+
+struct  mousevsc_prt_msg {
+	enum pipe_prot_msg_type type;
+	u32 size;
+	union {
+		struct synthhid_protocol_request request;
+		struct synthhid_protocol_response response;
+		struct synthhid_device_info_ack ack;
+	};
+};
+
+/*
+ * Represents an mousevsc device
+ */
+struct mousevsc_dev {
+	struct hv_device	*device;
+	bool			init_complete;
+	bool			connected;
+	struct mousevsc_prt_msg	protocol_req;
+	struct mousevsc_prt_msg	protocol_resp;
+	/* Synchronize the request/response if needed */
+	struct completion	wait_event;
+	int			dev_info_status;
+
+	struct hid_descriptor	*hid_desc;
+	unsigned char		*report_desc;
+	u32			report_desc_size;
+	struct hv_input_dev_info hid_dev_info;
+	struct hid_device       *hid_device;
+	u8			input_buf[HID_MAX_BUFFER_SIZE];
+};
+
+
+static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
+{
+	struct mousevsc_dev *input_dev;
+
+	input_dev = kzalloc_obj(struct mousevsc_dev);
+
+	if (!input_dev)
+		return NULL;
+
+	input_dev->device = device;
+	hv_set_drvdata(device, input_dev);
+	init_completion(&input_dev->wait_event);
+	input_dev->init_complete = false;
+
+	return input_dev;
+}
+
+static void mousevsc_free_device(struct mousevsc_dev *device)
+{
+	kfree(device->hid_desc);
+	kfree(device->report_desc);
+	hv_set_drvdata(device->device, NULL);
+	kfree(device);
+}
+
+static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
+					    struct synthhid_device_info *device_info,
+					    u32 device_info_size)
+{
+	int ret = 0;
+	struct hid_descriptor *desc;
+	struct mousevsc_prt_msg ack;
+	size_t desc_offset;
+	size_t desc_size;
+
+	input_device->dev_info_status = -ENOMEM;
+
+	if (device_info_size < sizeof(*device_info)) {
+		input_device->dev_info_status = -EINVAL;
+		goto cleanup;
+	}
+
+	input_device->hid_dev_info = device_info->hid_dev_info;
+	desc = &device_info->hid_descriptor;
+	desc_offset = offsetof(struct synthhid_device_info, hid_descriptor);
+	desc_size = device_info_size - desc_offset;
+	if (desc->bLength == 0)
+		goto cleanup;
+	if (desc->bLength < sizeof(*desc) || desc->bLength > desc_size) {
+		input_device->dev_info_status = -EINVAL;
+		goto cleanup;
+	}
+
+	/* The pointer is not NULL when we resume from hibernation */
+	kfree(input_device->hid_desc);
+	input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
+
+	if (!input_device->hid_desc)
+		goto cleanup;
+
+	input_device->report_desc_size = le16_to_cpu(
+					desc->rpt_desc.wDescriptorLength);
+	if (input_device->report_desc_size == 0) {
+		input_device->dev_info_status = -EINVAL;
+		goto cleanup;
+	}
+	if (input_device->report_desc_size > desc_size - desc->bLength) {
+		input_device->dev_info_status = -EINVAL;
+		goto cleanup;
+	}
+
+	/* The pointer is not NULL when we resume from hibernation */
+	kfree(input_device->report_desc);
+	input_device->report_desc = kzalloc(input_device->report_desc_size,
+					  GFP_ATOMIC);
+
+	if (!input_device->report_desc) {
+		input_device->dev_info_status = -ENOMEM;
+		goto cleanup;
+	}
+
+	memcpy(input_device->report_desc,
+	       ((unsigned char *)desc) + desc->bLength,
+	       le16_to_cpu(desc->rpt_desc.wDescriptorLength));
+
+	/* Send the ack */
+	memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
+
+	ack.type = PIPE_MESSAGE_DATA;
+	ack.size = sizeof(struct synthhid_device_info_ack);
+
+	ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
+	ack.ack.header.size = 1;
+	ack.ack.reserved = 0;
+
+	if (IS_ENABLED(CONFIG_HID_HYPERV_MOUSE_KUNIT_TEST) &&
+	    !input_device->device) {
+		ret = 0;
+	} else {
+		ret = vmbus_sendpacket(input_device->device->channel,
+				       &ack,
+				       sizeof(struct pipe_prt_msg) +
+				       sizeof(struct synthhid_device_info_ack),
+				       (unsigned long)&ack,
+				       VM_PKT_DATA_INBAND,
+				       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	}
+
+	if (!ret)
+		input_device->dev_info_status = 0;
+
+cleanup:
+	complete(&input_device->wait_event);
+
+	return;
+}
+
+static void mousevsc_on_receive(struct hv_device *device,
+				struct vmpacket_descriptor *packet)
+{
+	struct pipe_prt_msg *pipe_msg;
+	struct synthhid_msg_hdr *hid_msg_hdr;
+	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
+	struct synthhid_input_report *input_report;
+	size_t len;
+
+	pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
+						(packet->offset8 << 3));
+
+	if (pipe_msg->type != PIPE_MESSAGE_DATA)
+		return;
+
+	hid_msg_hdr = (struct synthhid_msg_hdr *)pipe_msg->data;
+
+	switch (hid_msg_hdr->type) {
+	case SYNTH_HID_PROTOCOL_RESPONSE:
+		len = struct_size(pipe_msg, data, pipe_msg->size);
+
+		/*
+		 * While it will be impossible for us to protect against
+		 * malicious/buggy hypervisor/host, add a check here to
+		 * ensure we don't corrupt memory.
+		 */
+		if (WARN_ON(len > sizeof(struct mousevsc_prt_msg)))
+			break;
+
+		memcpy(&input_dev->protocol_resp, pipe_msg, len);
+		complete(&input_dev->wait_event);
+		break;
+
+	case SYNTH_HID_INITIAL_DEVICE_INFO:
+		if (WARN_ON_ONCE(pipe_msg->size <
+				 sizeof(struct synthhid_device_info)))
+			break;
+
+		/*
+		 * Parse out the device info into device attr,
+		 * hid desc and report desc
+		 */
+		mousevsc_on_receive_device_info(input_dev,
+						(struct synthhid_device_info *)pipe_msg->data,
+						pipe_msg->size);
+		break;
+	case SYNTH_HID_INPUT_REPORT:
+		input_report =
+			(struct synthhid_input_report *)pipe_msg->data;
+		if (!input_dev->init_complete)
+			break;
+
+		len = min(input_report->header.size,
+			  (u32)sizeof(input_dev->input_buf));
+		memcpy(input_dev->input_buf, input_report->buffer, len);
+		hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
+				 input_dev->input_buf, len, 1);
+
+		pm_wakeup_hard_event(&input_dev->device->device);
+
+		break;
+	default:
+		pr_err("unsupported hid msg type - type %d len %d\n",
+		       hid_msg_hdr->type, hid_msg_hdr->size);
+		break;
+	}
+
+}
+
+static void mousevsc_on_channel_callback(void *context)
+{
+	struct hv_device *device = context;
+	struct vmpacket_descriptor *desc;
+
+	foreach_vmbus_pkt(desc, device->channel) {
+		switch (desc->type) {
+		case VM_PKT_COMP:
+			break;
+
+		case VM_PKT_DATA_INBAND:
+			mousevsc_on_receive(device, desc);
+			break;
+
+		default:
+			pr_err("Unhandled packet type %d, tid %llx len %d\n",
+			       desc->type, desc->trans_id, desc->len8 * 8);
+			break;
+		}
+	}
+}
+
+static int mousevsc_connect_to_vsp(struct hv_device *device)
+{
+	int ret = 0;
+	unsigned long t;
+	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
+	struct mousevsc_prt_msg *request;
+	struct mousevsc_prt_msg *response;
+
+	reinit_completion(&input_dev->wait_event);
+
+	request = &input_dev->protocol_req;
+	memset(request, 0, sizeof(struct mousevsc_prt_msg));
+
+	request->type = PIPE_MESSAGE_DATA;
+	request->size = sizeof(struct synthhid_protocol_request);
+	request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
+	request->request.header.size = sizeof(unsigned int);
+	request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
+
+	ret = vmbus_sendpacket(device->channel, request,
+				sizeof(struct pipe_prt_msg) +
+				sizeof(struct synthhid_protocol_request),
+				(unsigned long)request,
+				VM_PKT_DATA_INBAND,
+				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
+	if (!t) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	response = &input_dev->protocol_resp;
+
+	if (!response->response.approved) {
+		pr_err("synthhid protocol request failed (version %d)\n",
+		       SYNTHHID_INPUT_VERSION);
+		ret = -ENODEV;
+		goto cleanup;
+	}
+
+	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
+	if (!t) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	/*
+	 * We should have gotten the device attr, hid desc and report
+	 * desc at this point
+	 */
+	ret = input_dev->dev_info_status;
+
+cleanup:
+	return ret;
+}
+
+static int mousevsc_hid_parse(struct hid_device *hid)
+{
+	struct hv_device *dev = hid_get_drvdata(hid);
+	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
+
+	return hid_parse_report(hid, input_dev->report_desc,
+				input_dev->report_desc_size);
+}
+
+static int mousevsc_hid_open(struct hid_device *hid)
+{
+	return 0;
+}
+
+static int mousevsc_hid_start(struct hid_device *hid)
+{
+	return 0;
+}
+
+static void mousevsc_hid_close(struct hid_device *hid)
+{
+}
+
+static void mousevsc_hid_stop(struct hid_device *hid)
+{
+}
+
+static int mousevsc_hid_raw_request(struct hid_device *hid,
+				    unsigned char report_num,
+				    __u8 *buf, size_t len,
+				    unsigned char rtype,
+				    int reqtype)
+{
+	return 0;
+}
+
+static int mousevsc_hid_probe(struct hid_device *hid_dev, const struct hid_device_id *id)
+{
+	int ret;
+
+	ret = hid_parse(hid_dev);
+	if (ret) {
+		hid_err(hid_dev, "parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
+	if (ret) {
+		hid_err(hid_dev, "hw start failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct hid_ll_driver mousevsc_ll_driver = {
+	.parse = mousevsc_hid_parse,
+	.open = mousevsc_hid_open,
+	.close = mousevsc_hid_close,
+	.start = mousevsc_hid_start,
+	.stop = mousevsc_hid_stop,
+	.raw_request = mousevsc_hid_raw_request,
+};
+
+static const struct hid_device_id mousevsc_devices[] = {
+	{ HID_DEVICE(BUS_VIRTUAL, HID_GROUP_ANY, 0x045E, 0x0621) },
+	{ }
+};
+
+static struct hid_driver mousevsc_hid_driver = {
+	.name = "hid-hyperv",
+	.id_table = mousevsc_devices,
+	.probe = mousevsc_hid_probe,
+};
+
+static int mousevsc_probe(struct hv_device *device,
+			const struct hv_vmbus_device_id *dev_id)
+{
+	int ret;
+	struct mousevsc_dev *input_dev;
+	struct hid_device *hid_dev;
+
+	input_dev = mousevsc_alloc_device(device);
+
+	if (!input_dev)
+		return -ENOMEM;
+
+	ret = vmbus_open(device->channel,
+		INPUTVSC_SEND_RING_BUFFER_SIZE,
+		INPUTVSC_RECV_RING_BUFFER_SIZE,
+		NULL,
+		0,
+		mousevsc_on_channel_callback,
+		device
+		);
+
+	if (ret)
+		goto probe_err0;
+
+	ret = mousevsc_connect_to_vsp(device);
+
+	if (ret)
+		goto probe_err1;
+
+	/* workaround SA-167 */
+	if (input_dev->report_desc[14] == 0x25)
+		input_dev->report_desc[14] = 0x29;
+
+	hid_dev = hid_allocate_device();
+	if (IS_ERR(hid_dev)) {
+		ret = PTR_ERR(hid_dev);
+		goto probe_err1;
+	}
+
+	hid_dev->ll_driver = &mousevsc_ll_driver;
+	hid_dev->bus = BUS_VIRTUAL;
+	hid_dev->vendor = input_dev->hid_dev_info.vendor;
+	hid_dev->product = input_dev->hid_dev_info.product;
+	hid_dev->version = input_dev->hid_dev_info.version;
+	input_dev->hid_device = hid_dev;
+
+	sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
+
+	hid_set_drvdata(hid_dev, device);
+
+	ret = hid_add_device(hid_dev);
+	if (ret)
+		goto probe_err2;
+
+	device_init_wakeup(&device->device, true);
+
+	input_dev->connected = true;
+	input_dev->init_complete = true;
+
+	return ret;
+
+probe_err2:
+	hid_destroy_device(hid_dev);
+
+probe_err1:
+	vmbus_close(device->channel);
+
+probe_err0:
+	mousevsc_free_device(input_dev);
+
+	return ret;
+}
+
+
+static void mousevsc_remove(struct hv_device *dev)
+{
+	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
+
+	device_init_wakeup(&dev->device, false);
+	vmbus_close(dev->channel);
+	hid_hw_stop(input_dev->hid_device);
+	hid_destroy_device(input_dev->hid_device);
+	mousevsc_free_device(input_dev);
+}
+
+static int mousevsc_suspend(struct hv_device *dev)
+{
+	vmbus_close(dev->channel);
+
+	return 0;
+}
+
+static int mousevsc_resume(struct hv_device *dev)
+{
+	int ret;
+
+	ret = vmbus_open(dev->channel,
+			 INPUTVSC_SEND_RING_BUFFER_SIZE,
+			 INPUTVSC_RECV_RING_BUFFER_SIZE,
+			 NULL, 0,
+			 mousevsc_on_channel_callback,
+			 dev);
+	if (ret)
+		return ret;
+
+	ret = mousevsc_connect_to_vsp(dev);
+	return ret;
+}
+
+static const struct hv_vmbus_device_id id_table[] = {
+	/* Mouse guid */
+	{ HV_MOUSE_GUID, },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+static struct  hv_driver mousevsc_drv = {
+	.name = KBUILD_MODNAME,
+	.id_table = id_table,
+	.probe = mousevsc_probe,
+	.remove = mousevsc_remove,
+	.suspend = mousevsc_suspend,
+	.resume = mousevsc_resume,
+	.driver = {
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+
+static int __init mousevsc_init(void)
+{
+	int ret;
+
+	ret = hid_register_driver(&mousevsc_hid_driver);
+	if (ret)
+		return ret;
+
+	ret = vmbus_driver_register(&mousevsc_drv);
+	if (ret)
+		hid_unregister_driver(&mousevsc_hid_driver);
+
+	return ret;
+}
+
+static void __exit mousevsc_exit(void)
+{
+	vmbus_driver_unregister(&mousevsc_drv);
+	hid_unregister_driver(&mousevsc_hid_driver);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
+
+#if IS_ENABLED(CONFIG_HID_HYPERV_MOUSE_KUNIT_TEST)
+static struct mousevsc_dev *mousevsc_kunit_alloc_dev(struct kunit *test)
+{
+	struct mousevsc_dev *input_dev;
+
+	input_dev = kunit_kzalloc(test, sizeof(*input_dev), GFP_KERNEL);
+	if (!input_dev)
+		return NULL;
+
+	init_completion(&input_dev->wait_event);
+
+	return input_dev;
+}
+
+static void mousevsc_device_info_zero_blength(struct kunit *test)
+{
+	struct synthhid_device_info *info;
+	struct mousevsc_dev *input_dev;
+
+	input_dev = mousevsc_kunit_alloc_dev(test);
+	KUNIT_ASSERT_NOT_NULL(test, input_dev);
+	info = kunit_kzalloc(test, sizeof(*info), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, info);
+
+	info->hid_descriptor.bLength = 0;
+
+	mousevsc_on_receive_device_info(input_dev, info, sizeof(*info));
+
+	KUNIT_EXPECT_EQ(test, input_dev->dev_info_status, -ENOMEM);
+}
+
+static void mousevsc_device_info_valid_descriptor(struct kunit *test)
+{
+	struct synthhid_device_info *info;
+	struct mousevsc_dev *input_dev;
+	u8 *report;
+
+	input_dev = mousevsc_kunit_alloc_dev(test);
+	KUNIT_ASSERT_NOT_NULL(test, input_dev);
+	info = kunit_kzalloc(test, sizeof(*info) + 4, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, info);
+
+	info->hid_descriptor.bLength = sizeof(struct hid_descriptor);
+	info->hid_descriptor.rpt_desc.wDescriptorLength = cpu_to_le16(4);
+	report = ((u8 *)&info->hid_descriptor) + info->hid_descriptor.bLength;
+	memset(report, 0x42, 4);
+
+	mousevsc_on_receive_device_info(input_dev, info, sizeof(*info) + 4);
+
+	KUNIT_EXPECT_EQ(test, input_dev->dev_info_status, 0);
+	KUNIT_EXPECT_EQ(test, input_dev->report_desc_size, 4);
+	KUNIT_EXPECT_MEMEQ(test, input_dev->report_desc, report, 4);
+
+	kfree(input_dev->hid_desc);
+	kfree(input_dev->report_desc);
+}
+
+static void mousevsc_device_info_report_desc_oob(struct kunit *test)
+{
+	struct synthhid_device_info *info;
+	struct mousevsc_dev *input_dev;
+	u8 *report;
+
+	input_dev = mousevsc_kunit_alloc_dev(test);
+	KUNIT_ASSERT_NOT_NULL(test, input_dev);
+	info = kunit_kzalloc(test, sizeof(*info) + 8, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, info);
+
+	info->hid_descriptor.bLength = sizeof(struct hid_descriptor);
+	info->hid_descriptor.rpt_desc.wDescriptorLength = cpu_to_le16(64);
+	report = ((u8 *)&info->hid_descriptor) + info->hid_descriptor.bLength;
+	memset(report, 0x42, 8);
+
+	mousevsc_on_receive_device_info(input_dev, info, sizeof(*info) + 8);
+
+	KUNIT_EXPECT_EQ(test, input_dev->dev_info_status, -EINVAL);
+
+	kfree(input_dev->hid_desc);
+}
+
+static struct kunit_case mousevsc_test_cases[] = {
+	KUNIT_CASE(mousevsc_device_info_zero_blength),
+	KUNIT_CASE(mousevsc_device_info_valid_descriptor),
+	KUNIT_CASE(mousevsc_device_info_report_desc_oob),
+	{}
+};
+
+static struct kunit_suite mousevsc_test_suite = {
+	.name = "hid_hyperv_mouse",
+	.test_cases = mousevsc_test_cases,
+};
+
+kunit_test_suite(mousevsc_test_suite);
+#endif
+
+module_init(mousevsc_init);
+module_exit(mousevsc_exit);