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Bluetooth: hci_event: Introduce handle_ev_vendor() for HCI_EV_VENDOR

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Introduce the hook to solve issues below:

msft_vendor_evt(), the current handler for all VSEs, is unsuitable
since:
- many VSEs are not MSFT ones;
- it always corrupts the non-MSFT VSEs by calling skb_pull_data()
  once the MSFT extension is enabled.

Several issues are caused by many transport drivers pre-processing
VSEs in their RX path, often an IRQ-disabled atomic context. Take
the two typical cases below as examples:

Case 1:
  // no btmon log, no way to reach userspace
  Step 1: handle and free @original_skb directly

Case 2:
  // hurts performance and consumes GFP_ATOMIC memory
  Step 1: cloned_skb = skb_clone(original_skb, GFP_ATOMIC);
  // the VSE is handled here
  Step 2: handle and free @cloned_skb
  Step 3: hci_recv_frame(hdev, original_skb);
  // already handled, but re-enters the stack's event-handling path
  Step 4: hci_event_packet(hdev, original_skb);

Fix by introducing the hook with usage:
1) the transport driver registers the hook for VSEs of interest;
2) the stack calls it in process context, handling the VSE like any
   other event:
   - if interested, handle the VSE - no need to free it - and
     return true;
   - otherwise return false.

Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This commit is contained in:
Zijun Hu
2026-08-01 23:31:41 -07:00
committed by Luiz Augusto von Dentz
parent 73c4c035ae
commit 0bd606b31d
2 changed files with 11 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
include/net/bluetooth/hci_core.h
View File

@@ -646,6 +646,8 @@ struct hci_dev {
int (*setup)(struct hci_dev *hdev);
int (*shutdown)(struct hci_dev *hdev);
int (*send)(struct hci_dev *hdev, struct sk_buff *skb);
/* Handle HCI_EV_VENDOR; return true if handled, false otherwise */
bool (*handle_ev_vendor)(struct hci_dev *hdev, struct sk_buff *skb);
void (*notify)(struct hci_dev *hdev, unsigned int evt);
void (*hw_error)(struct hci_dev *hdev, u8 code);
int (*post_init)(struct hci_dev *hdev);

10
net/bluetooth/hci_event.c
View File

@@ -7604,6 +7604,14 @@ static void hci_le_meta_evt(struct hci_dev *hdev, void *data,
subev->func(hdev, data, skb);
}
static void hci_vendor_evt(struct hci_dev *hdev, void *data, struct sk_buff *skb)
{
if (hdev->handle_ev_vendor && hdev->handle_ev_vendor(hdev, skb))
return;
msft_vendor_evt(hdev, data, skb);
}
static bool hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode,
u8 event, struct sk_buff *skb)
{
@@ -7831,7 +7839,7 @@ static const struct hci_ev {
HCI_EV_REQ_VL(HCI_EV_LE_META, hci_le_meta_evt,
sizeof(struct hci_ev_le_meta), HCI_MAX_EVENT_SIZE),
/* [0xff = HCI_EV_VENDOR] */
HCI_EV_VL(HCI_EV_VENDOR, msft_vendor_evt, 0, HCI_MAX_EVENT_SIZE),
HCI_EV_VL(HCI_EV_VENDOR, hci_vendor_evt, 0, HCI_MAX_EVENT_SIZE),
};
static void hci_event_func(struct hci_dev *hdev, u8 event, struct sk_buff *skb,