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, 1206 insertions, 0 deletions

diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
new file mode 100644
index 000000000..ded68568e
--- /dev/null
+++ b/net/bluetooth/msft.c
@@ -0,0 +1,1206 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Google Corporation
+ */
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <net/bluetooth/mgmt.h>
+
+#include "mgmt_util.h"
+#include "msft.h"
+
+#define MSFT_RSSI_THRESHOLD_VALUE_MIN		-127
+#define MSFT_RSSI_THRESHOLD_VALUE_MAX		20
+#define MSFT_RSSI_LOW_TIMEOUT_MAX		0x3C
+
+#define MSFT_OP_READ_SUPPORTED_FEATURES		0x00
+struct msft_cp_read_supported_features {
+	__u8   sub_opcode;
+} __packed;
+
+struct msft_rp_read_supported_features {
+	__u8   status;
+	__u8   sub_opcode;
+	__le64 features;
+	__u8   evt_prefix_len;
+	__u8   evt_prefix[];
+} __packed;
+
+#define MSFT_OP_LE_MONITOR_ADVERTISEMENT	0x03
+#define MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN	0x01
+struct msft_le_monitor_advertisement_pattern {
+	__u8 length;
+	__u8 data_type;
+	__u8 start_byte;
+	__u8 pattern[];
+};
+
+struct msft_le_monitor_advertisement_pattern_data {
+	__u8 count;
+	__u8 data[];
+};
+
+struct msft_cp_le_monitor_advertisement {
+	__u8 sub_opcode;
+	__s8 rssi_high;
+	__s8 rssi_low;
+	__u8 rssi_low_interval;
+	__u8 rssi_sampling_period;
+	__u8 cond_type;
+	__u8 data[];
+} __packed;
+
+struct msft_rp_le_monitor_advertisement {
+	__u8 status;
+	__u8 sub_opcode;
+	__u8 handle;
+} __packed;
+
+#define MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT	0x04
+struct msft_cp_le_cancel_monitor_advertisement {
+	__u8 sub_opcode;
+	__u8 handle;
+} __packed;
+
+struct msft_rp_le_cancel_monitor_advertisement {
+	__u8 status;
+	__u8 sub_opcode;
+} __packed;
+
+#define MSFT_OP_LE_SET_ADVERTISEMENT_FILTER_ENABLE	0x05
+struct msft_cp_le_set_advertisement_filter_enable {
+	__u8 sub_opcode;
+	__u8 enable;
+} __packed;
+
+struct msft_rp_le_set_advertisement_filter_enable {
+	__u8 status;
+	__u8 sub_opcode;
+} __packed;
+
+#define MSFT_EV_LE_MONITOR_DEVICE	0x02
+struct msft_ev_le_monitor_device {
+	__u8     addr_type;
+	bdaddr_t bdaddr;
+	__u8     monitor_handle;
+	__u8     monitor_state;
+} __packed;
+
+struct msft_monitor_advertisement_handle_data {
+	__u8  msft_handle;
+	__u16 mgmt_handle;
+	__s8 rssi_high;
+	__s8 rssi_low;
+	__u8 rssi_low_interval;
+	__u8 rssi_sampling_period;
+	__u8 cond_type;
+	struct list_head list;
+};
+
+enum monitor_addr_filter_state {
+	AF_STATE_IDLE,
+	AF_STATE_ADDING,
+	AF_STATE_ADDED,
+	AF_STATE_REMOVING,
+};
+
+#define MSFT_MONITOR_ADVERTISEMENT_TYPE_ADDR	0x04
+struct msft_monitor_addr_filter_data {
+	__u8     msft_handle;
+	__u8     pattern_handle; /* address filters pertain to */
+	__u16    mgmt_handle;
+	int      state;
+	__s8     rssi_high;
+	__s8     rssi_low;
+	__u8     rssi_low_interval;
+	__u8     rssi_sampling_period;
+	__u8     addr_type;
+	bdaddr_t bdaddr;
+	struct list_head list;
+};
+
+struct msft_data {
+	__u64 features;
+	__u8  evt_prefix_len;
+	__u8  *evt_prefix;
+	struct list_head handle_map;
+	struct list_head address_filters;
+	__u8 resuming;
+	__u8 suspending;
+	__u8 filter_enabled;
+	/* To synchronize add/remove address filter and monitor device event.*/
+	struct mutex filter_lock;
+};
+
+bool msft_monitor_supported(struct hci_dev *hdev)
+{
+	return !!(msft_get_features(hdev) & MSFT_FEATURE_MASK_LE_ADV_MONITOR);
+}
+
+static bool read_supported_features(struct hci_dev *hdev,
+				    struct msft_data *msft)
+{
+	struct msft_cp_read_supported_features cp;
+	struct msft_rp_read_supported_features *rp;
+	struct sk_buff *skb;
+
+	cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES;
+
+	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
+			     HCI_CMD_TIMEOUT);
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "Failed to read MSFT supported features (%ld)",
+			   PTR_ERR(skb));
+		return false;
+	}
+
+	if (skb->len < sizeof(*rp)) {
+		bt_dev_err(hdev, "MSFT supported features length mismatch");
+		goto failed;
+	}
+
+	rp = (struct msft_rp_read_supported_features *)skb->data;
+
+	if (rp->sub_opcode != MSFT_OP_READ_SUPPORTED_FEATURES)
+		goto failed;
+
+	if (skb->len < sizeof(*rp) + rp->evt_prefix_len) {
+		bt_dev_err(hdev, "MSFT event prefix length mismatch");
+		goto failed;
+	}
+
+	if (rp->evt_prefix_len > 0) {
+		msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len,
+					   GFP_KERNEL);
+		if (!msft->evt_prefix)
+			goto failed;
+	}
+
+	msft->evt_prefix_len = rp->evt_prefix_len;
+	msft->features = __le64_to_cpu(rp->features);
+
+	if (msft->features & MSFT_FEATURE_MASK_CURVE_VALIDITY)
+		hdev->msft_curve_validity = true;
+
+	kfree_skb(skb);
+	return true;
+
+failed:
+	kfree_skb(skb);
+	return false;
+}
+
+/* is_mgmt = true matches the handle exposed to userspace via mgmt.
+ * is_mgmt = false matches the handle used by the msft controller.
+ * This function requires the caller holds hdev->lock
+ */
+static struct msft_monitor_advertisement_handle_data *msft_find_handle_data
+				(struct hci_dev *hdev, u16 handle, bool is_mgmt)
+{
+	struct msft_monitor_advertisement_handle_data *entry;
+	struct msft_data *msft = hdev->msft_data;
+
+	list_for_each_entry(entry, &msft->handle_map, list) {
+		if (is_mgmt && entry->mgmt_handle == handle)
+			return entry;
+		if (!is_mgmt && entry->msft_handle == handle)
+			return entry;
+	}
+
+	return NULL;
+}
+
+/* This function requires the caller holds msft->filter_lock */
+static struct msft_monitor_addr_filter_data *msft_find_address_data
+			(struct hci_dev *hdev, u8 addr_type, bdaddr_t *addr,
+			 u8 pattern_handle)
+{
+	struct msft_monitor_addr_filter_data *entry;
+	struct msft_data *msft = hdev->msft_data;
+
+	list_for_each_entry(entry, &msft->address_filters, list) {
+		if (entry->pattern_handle == pattern_handle &&
+		    addr_type == entry->addr_type &&
+		    !bacmp(addr, &entry->bdaddr))
+			return entry;
+	}
+
+	return NULL;
+}
+
+/* This function requires the caller holds hdev->lock */
+static int msft_monitor_device_del(struct hci_dev *hdev, __u16 mgmt_handle,
+				   bdaddr_t *bdaddr, __u8 addr_type,
+				   bool notify)
+{
+	struct monitored_device *dev, *tmp;
+	int count = 0;
+
+	list_for_each_entry_safe(dev, tmp, &hdev->monitored_devices, list) {
+		/* mgmt_handle == 0 indicates remove all devices, whereas,
+		 * bdaddr == NULL indicates remove all devices matching the
+		 * mgmt_handle.
+		 */
+		if ((!mgmt_handle || dev->handle == mgmt_handle) &&
+		    (!bdaddr || (!bacmp(bdaddr, &dev->bdaddr) &&
+				 addr_type == dev->addr_type))) {
+			if (notify && dev->notified) {
+				mgmt_adv_monitor_device_lost(hdev, dev->handle,
+							     &dev->bdaddr,
+							     dev->addr_type);
+			}
+
+			list_del(&dev->list);
+			kfree(dev);
+			count++;
+		}
+	}
+
+	return count;
+}
+
+static int msft_le_monitor_advertisement_cb(struct hci_dev *hdev, u16 opcode,
+					    struct adv_monitor *monitor,
+					    struct sk_buff *skb)
+{
+	struct msft_rp_le_monitor_advertisement *rp;
+	struct msft_monitor_advertisement_handle_data *handle_data;
+	struct msft_data *msft = hdev->msft_data;
+	int status = 0;
+
+	hci_dev_lock(hdev);
+
+	rp = (struct msft_rp_le_monitor_advertisement *)skb->data;
+	if (skb->len < sizeof(*rp)) {
+		status = HCI_ERROR_UNSPECIFIED;
+		goto unlock;
+	}
+
+	status = rp->status;
+	if (status)
+		goto unlock;
+
+	handle_data = kmalloc_obj(*handle_data);
+	if (!handle_data) {
+		status = HCI_ERROR_UNSPECIFIED;
+		goto unlock;
+	}
+
+	handle_data->mgmt_handle = monitor->handle;
+	handle_data->msft_handle = rp->handle;
+	handle_data->cond_type   = MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN;
+	INIT_LIST_HEAD(&handle_data->list);
+	list_add(&handle_data->list, &msft->handle_map);
+
+	monitor->state = ADV_MONITOR_STATE_OFFLOADED;
+
+unlock:
+	if (status && msft->resuming)
+		hci_free_adv_monitor(hdev, monitor);
+
+	hci_dev_unlock(hdev);
+
+	return status;
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+static void msft_remove_addr_filters_sync(struct hci_dev *hdev, u8 handle)
+{
+	struct msft_monitor_addr_filter_data *address_filter, *n;
+	struct msft_cp_le_cancel_monitor_advertisement cp;
+	struct msft_data *msft = hdev->msft_data;
+	struct list_head head;
+	struct sk_buff *skb;
+
+	INIT_LIST_HEAD(&head);
+
+	/* Cancel all corresponding address monitors */
+	mutex_lock(&msft->filter_lock);
+
+	list_for_each_entry_safe(address_filter, n, &msft->address_filters,
+				 list) {
+		if (address_filter->pattern_handle != handle)
+			continue;
+
+		list_del(&address_filter->list);
+
+		/* Keep the address filter and let
+		 * msft_add_address_filter_sync() remove and free the address
+		 * filter.
+		 */
+		if (address_filter->state == AF_STATE_ADDING) {
+			address_filter->state = AF_STATE_REMOVING;
+			continue;
+		}
+
+		/* Keep the address filter and let
+		 * msft_cancel_address_filter_sync() remove and free the address
+		 * filter
+		 */
+		if (address_filter->state == AF_STATE_REMOVING)
+			continue;
+
+		list_add_tail(&address_filter->list, &head);
+	}
+
+	mutex_unlock(&msft->filter_lock);
+
+	list_for_each_entry_safe(address_filter, n, &head, list) {
+		list_del(&address_filter->list);
+
+		cp.sub_opcode = MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT;
+		cp.handle = address_filter->msft_handle;
+
+		skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
+				     HCI_CMD_TIMEOUT);
+		if (IS_ERR(skb)) {
+			kfree(address_filter);
+			continue;
+		}
+
+		kfree_skb(skb);
+
+		bt_dev_dbg(hdev, "MSFT: Canceled device %pMR address filter",
+			   &address_filter->bdaddr);
+
+		kfree(address_filter);
+	}
+}
+
+static int msft_le_cancel_monitor_advertisement_cb(struct hci_dev *hdev,
+						   u16 opcode,
+						   struct adv_monitor *monitor,
+						   struct sk_buff *skb)
+{
+	struct msft_rp_le_cancel_monitor_advertisement *rp;
+	struct msft_monitor_advertisement_handle_data *handle_data;
+	struct msft_data *msft = hdev->msft_data;
+	int status = 0;
+	u8 msft_handle;
+
+	rp = (struct msft_rp_le_cancel_monitor_advertisement *)skb->data;
+	if (skb->len < sizeof(*rp)) {
+		status = HCI_ERROR_UNSPECIFIED;
+		goto done;
+	}
+
+	status = rp->status;
+	if (status)
+		goto done;
+
+	hci_dev_lock(hdev);
+
+	handle_data = msft_find_handle_data(hdev, monitor->handle, true);
+
+	if (handle_data) {
+		if (monitor->state == ADV_MONITOR_STATE_OFFLOADED)
+			monitor->state = ADV_MONITOR_STATE_REGISTERED;
+
+		/* Do not free the monitor if it is being removed due to
+		 * suspend. It will be re-monitored on resume.
+		 */
+		if (!msft->suspending) {
+			hci_free_adv_monitor(hdev, monitor);
+
+			/* Clear any monitored devices by this Adv Monitor */
+			msft_monitor_device_del(hdev, handle_data->mgmt_handle,
+						NULL, 0, false);
+		}
+
+		msft_handle = handle_data->msft_handle;
+
+		list_del(&handle_data->list);
+		kfree(handle_data);
+
+		hci_dev_unlock(hdev);
+
+		msft_remove_addr_filters_sync(hdev, msft_handle);
+	} else {
+		hci_dev_unlock(hdev);
+	}
+
+done:
+	return status;
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+static int msft_remove_monitor_sync(struct hci_dev *hdev,
+				    struct adv_monitor *monitor)
+{
+	struct msft_cp_le_cancel_monitor_advertisement cp;
+	struct msft_monitor_advertisement_handle_data *handle_data;
+	struct sk_buff *skb;
+
+	handle_data = msft_find_handle_data(hdev, monitor->handle, true);
+
+	/* If no matched handle, just remove without telling controller */
+	if (!handle_data)
+		return -ENOENT;
+
+	cp.sub_opcode = MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT;
+	cp.handle = handle_data->msft_handle;
+
+	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
+			     HCI_CMD_TIMEOUT);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	return msft_le_cancel_monitor_advertisement_cb(hdev, hdev->msft_opcode,
+						       monitor, skb);
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+int msft_suspend_sync(struct hci_dev *hdev)
+{
+	struct msft_data *msft = hdev->msft_data;
+	struct adv_monitor *monitor;
+	int handle = 0;
+
+	if (!msft || !msft_monitor_supported(hdev))
+		return 0;
+
+	msft->suspending = true;
+
+	while (1) {
+		monitor = idr_get_next(&hdev->adv_monitors_idr, &handle);
+		if (!monitor)
+			break;
+
+		msft_remove_monitor_sync(hdev, monitor);
+
+		handle++;
+	}
+
+	/* All monitors have been removed */
+	msft->suspending = false;
+
+	return 0;
+}
+
+static bool msft_monitor_rssi_valid(struct adv_monitor *monitor)
+{
+	struct adv_rssi_thresholds *r = &monitor->rssi;
+
+	if (r->high_threshold < MSFT_RSSI_THRESHOLD_VALUE_MIN ||
+	    r->high_threshold > MSFT_RSSI_THRESHOLD_VALUE_MAX ||
+	    r->low_threshold < MSFT_RSSI_THRESHOLD_VALUE_MIN ||
+	    r->low_threshold > MSFT_RSSI_THRESHOLD_VALUE_MAX)
+		return false;
+
+	/* High_threshold_timeout is not supported,
+	 * once high_threshold is reached, events are immediately reported.
+	 */
+	if (r->high_threshold_timeout != 0)
+		return false;
+
+	if (r->low_threshold_timeout > MSFT_RSSI_LOW_TIMEOUT_MAX)
+		return false;
+
+	/* Sampling period from 0x00 to 0xFF are all allowed */
+	return true;
+}
+
+static bool msft_monitor_pattern_valid(struct adv_monitor *monitor)
+{
+	return msft_monitor_rssi_valid(monitor);
+	/* No additional check needed for pattern-based monitor */
+}
+
+static int msft_add_monitor_sync(struct hci_dev *hdev,
+				 struct adv_monitor *monitor)
+{
+	struct msft_cp_le_monitor_advertisement *cp;
+	struct msft_le_monitor_advertisement_pattern_data *pattern_data;
+	struct msft_monitor_advertisement_handle_data *handle_data;
+	struct msft_le_monitor_advertisement_pattern *pattern;
+	struct adv_pattern *entry;
+	size_t total_size = sizeof(*cp) + sizeof(*pattern_data);
+	ptrdiff_t offset = 0;
+	u8 pattern_count = 0;
+	struct sk_buff *skb;
+	int err;
+
+	if (!msft_monitor_pattern_valid(monitor))
+		return -EINVAL;
+
+	list_for_each_entry(entry, &monitor->patterns, list) {
+		pattern_count++;
+		total_size += sizeof(*pattern) + entry->length;
+	}
+
+	cp = kmalloc(total_size, GFP_KERNEL);
+	if (!cp)
+		return -ENOMEM;
+
+	cp->sub_opcode = MSFT_OP_LE_MONITOR_ADVERTISEMENT;
+	cp->rssi_high = monitor->rssi.high_threshold;
+	cp->rssi_low = monitor->rssi.low_threshold;
+	cp->rssi_low_interval = (u8)monitor->rssi.low_threshold_timeout;
+	cp->rssi_sampling_period = monitor->rssi.sampling_period;
+
+	cp->cond_type = MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN;
+
+	pattern_data = (void *)cp->data;
+	pattern_data->count = pattern_count;
+
+	list_for_each_entry(entry, &monitor->patterns, list) {
+		pattern = (void *)(pattern_data->data + offset);
+		/* the length also includes data_type and offset */
+		pattern->length = entry->length + 2;
+		pattern->data_type = entry->ad_type;
+		pattern->start_byte = entry->offset;
+		memcpy(pattern->pattern, entry->value, entry->length);
+		offset += sizeof(*pattern) + entry->length;
+	}
+
+	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, total_size, cp,
+			     HCI_CMD_TIMEOUT);
+
+	if (IS_ERR(skb)) {
+		err = PTR_ERR(skb);
+		goto out_free;
+	}
+
+	err = msft_le_monitor_advertisement_cb(hdev, hdev->msft_opcode,
+					       monitor, skb);
+	if (err)
+		goto out_free;
+
+	handle_data = msft_find_handle_data(hdev, monitor->handle, true);
+	if (!handle_data) {
+		err = -ENODATA;
+		goto out_free;
+	}
+
+	handle_data->rssi_high	= cp->rssi_high;
+	handle_data->rssi_low	= cp->rssi_low;
+	handle_data->rssi_low_interval	  = cp->rssi_low_interval;
+	handle_data->rssi_sampling_period = cp->rssi_sampling_period;
+
+out_free:
+	kfree(cp);
+	return err;
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+static void reregister_monitor(struct hci_dev *hdev)
+{
+	struct adv_monitor *monitor;
+	struct msft_data *msft = hdev->msft_data;
+	int handle = 0;
+
+	if (!msft)
+		return;
+
+	msft->resuming = true;
+
+	while (1) {
+		monitor = idr_get_next(&hdev->adv_monitors_idr, &handle);
+		if (!monitor)
+			break;
+
+		msft_add_monitor_sync(hdev, monitor);
+
+		handle++;
+	}
+
+	/* All monitors have been reregistered */
+	msft->resuming = false;
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+int msft_resume_sync(struct hci_dev *hdev)
+{
+	struct msft_data *msft = hdev->msft_data;
+
+	if (!msft || !msft_monitor_supported(hdev))
+		return 0;
+
+	hci_dev_lock(hdev);
+
+	/* Clear already tracked devices on resume. Once the monitors are
+	 * reregistered, devices in range will be found again after resume.
+	 */
+	hdev->advmon_pend_notify = false;
+	msft_monitor_device_del(hdev, 0, NULL, 0, true);
+
+	hci_dev_unlock(hdev);
+
+	reregister_monitor(hdev);
+
+	return 0;
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+void msft_do_open(struct hci_dev *hdev)
+{
+	struct msft_data *msft = hdev->msft_data;
+
+	if (hdev->msft_opcode == HCI_OP_NOP)
+		return;
+
+	if (!msft) {
+		bt_dev_err(hdev, "MSFT extension not registered");
+		return;
+	}
+
+	bt_dev_dbg(hdev, "Initialize MSFT extension");
+
+	/* Reset existing MSFT data before re-reading */
+	kfree(msft->evt_prefix);
+	msft->evt_prefix = NULL;
+	msft->evt_prefix_len = 0;
+	msft->features = 0;
+
+	if (!read_supported_features(hdev, msft)) {
+		hdev->msft_data = NULL;
+		kfree(msft);
+		return;
+	}
+
+	if (msft_monitor_supported(hdev)) {
+		msft->resuming = true;
+		msft_set_filter_enable(hdev, true);
+		/* Monitors get removed on power off, so we need to explicitly
+		 * tell the controller to re-monitor.
+		 */
+		reregister_monitor(hdev);
+	}
+}
+
+void msft_do_close(struct hci_dev *hdev)
+{
+	struct msft_data *msft = hdev->msft_data;
+	struct msft_monitor_advertisement_handle_data *handle_data, *tmp;
+	struct msft_monitor_addr_filter_data *address_filter, *n;
+	struct adv_monitor *monitor;
+
+	if (!msft)
+		return;
+
+	bt_dev_dbg(hdev, "Cleanup of MSFT extension");
+
+	/* The controller will silently remove all monitors on power off.
+	 * Therefore, remove handle_data mapping and reset monitor state.
+	 */
+	list_for_each_entry_safe(handle_data, tmp, &msft->handle_map, list) {
+		monitor = idr_find(&hdev->adv_monitors_idr,
+				   handle_data->mgmt_handle);
+
+		if (monitor && monitor->state == ADV_MONITOR_STATE_OFFLOADED)
+			monitor->state = ADV_MONITOR_STATE_REGISTERED;
+
+		list_del(&handle_data->list);
+		kfree(handle_data);
+	}
+
+	mutex_lock(&msft->filter_lock);
+	list_for_each_entry_safe(address_filter, n, &msft->address_filters,
+				 list) {
+		list_del(&address_filter->list);
+		kfree(address_filter);
+	}
+	mutex_unlock(&msft->filter_lock);
+
+	hci_dev_lock(hdev);
+
+	/* Clear any devices that are being monitored and notify device lost */
+	hdev->advmon_pend_notify = false;
+	msft_monitor_device_del(hdev, 0, NULL, 0, true);
+
+	hci_dev_unlock(hdev);
+}
+
+static int msft_cancel_address_filter_sync(struct hci_dev *hdev, void *data)
+{
+	struct msft_monitor_addr_filter_data *address_filter = data;
+	struct msft_cp_le_cancel_monitor_advertisement cp;
+	struct msft_data *msft = hdev->msft_data;
+	struct sk_buff *skb;
+	int err = 0;
+
+	if (!msft) {
+		bt_dev_err(hdev, "MSFT: msft data is freed");
+		return -EINVAL;
+	}
+
+	/* The address filter has been removed by hci dev close */
+	if (!test_bit(HCI_UP, &hdev->flags))
+		return 0;
+
+	mutex_lock(&msft->filter_lock);
+	list_del(&address_filter->list);
+	mutex_unlock(&msft->filter_lock);
+
+	cp.sub_opcode = MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT;
+	cp.handle = address_filter->msft_handle;
+
+	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
+			     HCI_CMD_TIMEOUT);
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "MSFT: Failed to cancel address (%pMR) filter",
+			   &address_filter->bdaddr);
+		err = PTR_ERR(skb);
+		goto done;
+	}
+	kfree_skb(skb);
+
+	bt_dev_dbg(hdev, "MSFT: Canceled device %pMR address filter",
+		   &address_filter->bdaddr);
+
+done:
+	kfree(address_filter);
+
+	return err;
+}
+
+void msft_register(struct hci_dev *hdev)
+{
+	struct msft_data *msft = NULL;
+
+	bt_dev_dbg(hdev, "Register MSFT extension");
+
+	msft = kzalloc_obj(*msft);
+	if (!msft) {
+		bt_dev_err(hdev, "Failed to register MSFT extension");
+		return;
+	}
+
+	INIT_LIST_HEAD(&msft->handle_map);
+	INIT_LIST_HEAD(&msft->address_filters);
+	hdev->msft_data = msft;
+	mutex_init(&msft->filter_lock);
+}
+
+void msft_release(struct hci_dev *hdev)
+{
+	struct msft_data *msft = hdev->msft_data;
+
+	if (!msft)
+		return;
+
+	bt_dev_dbg(hdev, "Unregister MSFT extension");
+
+	hdev->msft_data = NULL;
+
+	kfree(msft->evt_prefix);
+	mutex_destroy(&msft->filter_lock);
+	kfree(msft);
+}
+
+/* This function requires the caller holds hdev->lock */
+static void msft_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr,
+			      __u8 addr_type, __u16 mgmt_handle)
+{
+	struct monitored_device *dev;
+
+	dev = kmalloc_obj(*dev);
+	if (!dev) {
+		bt_dev_err(hdev, "MSFT vendor event %u: no memory",
+			   MSFT_EV_LE_MONITOR_DEVICE);
+		return;
+	}
+
+	bacpy(&dev->bdaddr, bdaddr);
+	dev->addr_type = addr_type;
+	dev->handle = mgmt_handle;
+	dev->notified = false;
+
+	INIT_LIST_HEAD(&dev->list);
+	list_add(&dev->list, &hdev->monitored_devices);
+	hdev->advmon_pend_notify = true;
+}
+
+/* This function requires the caller holds hdev->lock */
+static void msft_device_lost(struct hci_dev *hdev, bdaddr_t *bdaddr,
+			     __u8 addr_type, __u16 mgmt_handle)
+{
+	if (!msft_monitor_device_del(hdev, mgmt_handle, bdaddr, addr_type,
+				     true)) {
+		bt_dev_err(hdev, "MSFT vendor event %u: dev %pMR not in list",
+			   MSFT_EV_LE_MONITOR_DEVICE, bdaddr);
+	}
+}
+
+static void *msft_skb_pull(struct hci_dev *hdev, struct sk_buff *skb,
+			   u8 ev, size_t len)
+{
+	void *data;
+
+	data = skb_pull_data(skb, len);
+	if (!data)
+		bt_dev_err(hdev, "Malformed MSFT vendor event: 0x%02x", ev);
+
+	return data;
+}
+
+static int msft_add_address_filter_sync(struct hci_dev *hdev, void *data)
+{
+	struct msft_monitor_addr_filter_data *address_filter = data;
+	struct msft_rp_le_monitor_advertisement *rp;
+	struct msft_cp_le_monitor_advertisement *cp;
+	struct msft_data *msft = hdev->msft_data;
+	struct sk_buff *skb = NULL;
+	bool remove = false;
+	size_t size;
+
+	if (!msft) {
+		bt_dev_err(hdev, "MSFT: msft data is freed");
+		return -EINVAL;
+	}
+
+	/* The address filter has been removed by hci dev close */
+	if (!test_bit(HCI_UP, &hdev->flags))
+		return -ENODEV;
+
+	/* We are safe to use the address filter from now on.
+	 * msft_monitor_device_evt() wouldn't delete this filter because it's
+	 * not been added by now.
+	 * And all other functions that requiring hci_req_sync_lock wouldn't
+	 * touch this filter before this func completes because it's protected
+	 * by hci_req_sync_lock.
+	 */
+
+	if (address_filter->state == AF_STATE_REMOVING) {
+		mutex_lock(&msft->filter_lock);
+		list_del(&address_filter->list);
+		mutex_unlock(&msft->filter_lock);
+		kfree(address_filter);
+		return 0;
+	}
+
+	size = sizeof(*cp) +
+	       sizeof(address_filter->addr_type) +
+	       sizeof(address_filter->bdaddr);
+	cp = kzalloc(size, GFP_KERNEL);
+	if (!cp) {
+		bt_dev_err(hdev, "MSFT: Alloc cmd param err");
+		remove = true;
+		goto done;
+	}
+
+	cp->sub_opcode           = MSFT_OP_LE_MONITOR_ADVERTISEMENT;
+	cp->rssi_high		 = address_filter->rssi_high;
+	cp->rssi_low		 = address_filter->rssi_low;
+	cp->rssi_low_interval    = address_filter->rssi_low_interval;
+	cp->rssi_sampling_period = address_filter->rssi_sampling_period;
+	cp->cond_type            = MSFT_MONITOR_ADVERTISEMENT_TYPE_ADDR;
+	cp->data[0]              = address_filter->addr_type;
+	memcpy(&cp->data[1], &address_filter->bdaddr,
+	       sizeof(address_filter->bdaddr));
+
+	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, size, cp,
+			     HCI_CMD_TIMEOUT);
+	kfree(cp);
+
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "Failed to enable address %pMR filter",
+			   &address_filter->bdaddr);
+		skb = NULL;
+		remove = true;
+		goto done;
+	}
+
+	rp = skb_pull_data(skb, sizeof(*rp));
+	if (!rp || rp->sub_opcode != MSFT_OP_LE_MONITOR_ADVERTISEMENT ||
+	    rp->status)
+		remove = true;
+
+done:
+	mutex_lock(&msft->filter_lock);
+
+	if (remove) {
+		bt_dev_warn(hdev, "MSFT: Remove address (%pMR) filter",
+			    &address_filter->bdaddr);
+		list_del(&address_filter->list);
+		kfree(address_filter);
+	} else {
+		address_filter->state = AF_STATE_ADDED;
+		address_filter->msft_handle = rp->handle;
+		bt_dev_dbg(hdev, "MSFT: Address %pMR filter enabled",
+			   &address_filter->bdaddr);
+	}
+	mutex_unlock(&msft->filter_lock);
+
+	kfree_skb(skb);
+
+	return 0;
+}
+
+/* This function requires the caller holds msft->filter_lock */
+static struct msft_monitor_addr_filter_data *msft_add_address_filter
+		(struct hci_dev *hdev, u8 addr_type, bdaddr_t *bdaddr,
+		 struct msft_monitor_advertisement_handle_data *handle_data)
+{
+	struct msft_monitor_addr_filter_data *address_filter = NULL;
+	struct msft_data *msft = hdev->msft_data;
+	int err;
+
+	address_filter = kzalloc_obj(*address_filter);
+	if (!address_filter)
+		return NULL;
+
+	address_filter->state             = AF_STATE_ADDING;
+	address_filter->msft_handle       = 0xff;
+	address_filter->pattern_handle    = handle_data->msft_handle;
+	address_filter->mgmt_handle       = handle_data->mgmt_handle;
+	address_filter->rssi_high         = handle_data->rssi_high;
+	address_filter->rssi_low          = handle_data->rssi_low;
+	address_filter->rssi_low_interval = handle_data->rssi_low_interval;
+	address_filter->rssi_sampling_period = handle_data->rssi_sampling_period;
+	address_filter->addr_type            = addr_type;
+	bacpy(&address_filter->bdaddr, bdaddr);
+
+	/* With the above AF_STATE_ADDING, duplicated address filter can be
+	 * avoided when receiving monitor device event (found/lost) frequently
+	 * for the same device.
+	 */
+	list_add_tail(&address_filter->list, &msft->address_filters);
+
+	err = hci_cmd_sync_queue(hdev, msft_add_address_filter_sync,
+				 address_filter, NULL);
+	if (err < 0) {
+		bt_dev_err(hdev, "MSFT: Add address %pMR filter err", bdaddr);
+		list_del(&address_filter->list);
+		kfree(address_filter);
+		return NULL;
+	}
+
+	bt_dev_dbg(hdev, "MSFT: Add device %pMR address filter",
+		   &address_filter->bdaddr);
+
+	return address_filter;
+}
+
+/* This function requires the caller holds hdev->lock */
+static void msft_monitor_device_evt(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct msft_monitor_addr_filter_data *n, *address_filter = NULL;
+	struct msft_ev_le_monitor_device *ev;
+	struct msft_monitor_advertisement_handle_data *handle_data;
+	struct msft_data *msft = hdev->msft_data;
+	u16 mgmt_handle = 0xffff;
+	u8 addr_type;
+
+	ev = msft_skb_pull(hdev, skb, MSFT_EV_LE_MONITOR_DEVICE, sizeof(*ev));
+	if (!ev)
+		return;
+
+	bt_dev_dbg(hdev,
+		   "MSFT vendor event 0x%02x: handle 0x%04x state %d addr %pMR",
+		   MSFT_EV_LE_MONITOR_DEVICE, ev->monitor_handle,
+		   ev->monitor_state, &ev->bdaddr);
+
+	handle_data = msft_find_handle_data(hdev, ev->monitor_handle, false);
+
+	if (!hci_test_quirk(hdev, HCI_QUIRK_USE_MSFT_EXT_ADDRESS_FILTER)) {
+		if (!handle_data)
+			return;
+		mgmt_handle = handle_data->mgmt_handle;
+		goto report_state;
+	}
+
+	if (handle_data) {
+		/* Don't report any device found/lost event from pattern
+		 * monitors. Pattern monitor always has its address filters for
+		 * tracking devices.
+		 */
+
+		address_filter = msft_find_address_data(hdev, ev->addr_type,
+							&ev->bdaddr,
+							handle_data->msft_handle);
+		if (address_filter)
+			return;
+
+		if (ev->monitor_state && handle_data->cond_type ==
+				MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN)
+			msft_add_address_filter(hdev, ev->addr_type,
+						&ev->bdaddr, handle_data);
+
+		return;
+	}
+
+	/* This device event is not from pattern monitor.
+	 * Report it if there is a corresponding address_filter for it.
+	 */
+	list_for_each_entry(n, &msft->address_filters, list) {
+		if (n->state == AF_STATE_ADDED &&
+		    n->msft_handle == ev->monitor_handle) {
+			mgmt_handle = n->mgmt_handle;
+			address_filter = n;
+			break;
+		}
+	}
+
+	if (!address_filter) {
+		bt_dev_warn(hdev, "MSFT: Unexpected device event %pMR, %u, %u",
+			    &ev->bdaddr, ev->monitor_handle, ev->monitor_state);
+		return;
+	}
+
+report_state:
+	switch (ev->addr_type) {
+	case ADDR_LE_DEV_PUBLIC:
+		addr_type = BDADDR_LE_PUBLIC;
+		break;
+
+	case ADDR_LE_DEV_RANDOM:
+		addr_type = BDADDR_LE_RANDOM;
+		break;
+
+	default:
+		bt_dev_err(hdev,
+			   "MSFT vendor event 0x%02x: unknown addr type 0x%02x",
+			   MSFT_EV_LE_MONITOR_DEVICE, ev->addr_type);
+		return;
+	}
+
+	if (ev->monitor_state) {
+		msft_device_found(hdev, &ev->bdaddr, addr_type, mgmt_handle);
+	} else {
+		if (address_filter && address_filter->state == AF_STATE_ADDED) {
+			address_filter->state = AF_STATE_REMOVING;
+			hci_cmd_sync_queue(hdev,
+					   msft_cancel_address_filter_sync,
+					   address_filter,
+					   NULL);
+		}
+		msft_device_lost(hdev, &ev->bdaddr, addr_type, mgmt_handle);
+	}
+}
+
+void msft_vendor_evt(struct hci_dev *hdev, void *data, struct sk_buff *skb)
+{
+	struct msft_data *msft = hdev->msft_data;
+	u8 *evt_prefix;
+	u8 *evt;
+
+	if (!msft)
+		return;
+
+	/* When the extension has defined an event prefix, check that it
+	 * matches, and otherwise just return.
+	 */
+	if (msft->evt_prefix_len > 0) {
+		evt_prefix = msft_skb_pull(hdev, skb, 0, msft->evt_prefix_len);
+		if (!evt_prefix)
+			return;
+
+		if (memcmp(evt_prefix, msft->evt_prefix, msft->evt_prefix_len))
+			return;
+	}
+
+	/* Every event starts at least with an event code and the rest of
+	 * the data is variable and depends on the event code.
+	 */
+	if (skb->len < 1)
+		return;
+
+	evt = msft_skb_pull(hdev, skb, 0, sizeof(*evt));
+	if (!evt)
+		return;
+
+	hci_dev_lock(hdev);
+
+	switch (*evt) {
+	case MSFT_EV_LE_MONITOR_DEVICE:
+		mutex_lock(&msft->filter_lock);
+		msft_monitor_device_evt(hdev, skb);
+		mutex_unlock(&msft->filter_lock);
+		break;
+
+	default:
+		bt_dev_dbg(hdev, "MSFT vendor event 0x%02x", *evt);
+		break;
+	}
+
+	hci_dev_unlock(hdev);
+}
+
+__u64 msft_get_features(struct hci_dev *hdev)
+{
+	struct msft_data *msft = hdev->msft_data;
+
+	return msft ? msft->features : 0;
+}
+
+static void msft_le_set_advertisement_filter_enable_cb(struct hci_dev *hdev,
+						       void *user_data,
+						       u8 status)
+{
+	struct msft_cp_le_set_advertisement_filter_enable *cp = user_data;
+	struct msft_data *msft = hdev->msft_data;
+
+	/* Error 0x0C would be returned if the filter enabled status is
+	 * already set to whatever we were trying to set.
+	 * Although the default state should be disabled, some controller set
+	 * the initial value to enabled. Because there is no way to know the
+	 * actual initial value before sending this command, here we also treat
+	 * error 0x0C as success.
+	 */
+	if (status != 0x00 && status != 0x0C)
+		return;
+
+	hci_dev_lock(hdev);
+
+	msft->filter_enabled = cp->enable;
+
+	if (status == 0x0C)
+		bt_dev_warn(hdev, "MSFT filter_enable is already %s",
+			    cp->enable ? "on" : "off");
+
+	hci_dev_unlock(hdev);
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+int msft_add_monitor_pattern(struct hci_dev *hdev, struct adv_monitor *monitor)
+{
+	struct msft_data *msft = hdev->msft_data;
+
+	if (!msft)
+		return -EOPNOTSUPP;
+
+	if (msft->resuming || msft->suspending)
+		return -EBUSY;
+
+	return msft_add_monitor_sync(hdev, monitor);
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor)
+{
+	struct msft_data *msft = hdev->msft_data;
+
+	if (!msft)
+		return -EOPNOTSUPP;
+
+	if (msft->resuming || msft->suspending)
+		return -EBUSY;
+
+	return msft_remove_monitor_sync(hdev, monitor);
+}
+
+int msft_set_filter_enable(struct hci_dev *hdev, bool enable)
+{
+	struct msft_cp_le_set_advertisement_filter_enable cp;
+	struct msft_data *msft = hdev->msft_data;
+	int err;
+
+	if (!msft)
+		return -EOPNOTSUPP;
+
+	cp.sub_opcode = MSFT_OP_LE_SET_ADVERTISEMENT_FILTER_ENABLE;
+	cp.enable = enable;
+	err = __hci_cmd_sync_status(hdev, hdev->msft_opcode, sizeof(cp), &cp,
+				    HCI_CMD_TIMEOUT);
+
+	msft_le_set_advertisement_filter_enable_cb(hdev, &cp, err);
+
+	return 0;
+}
+
+bool msft_curve_validity(struct hci_dev *hdev)
+{
+	return hdev->msft_curve_validity;
+}