2018-11-08 05:52:50

by Zumeng Chen

[permalink] [raw]
Subject: [PATCH 1/1] Bluetooth: make the balance of judgement condition to fix a false report

This patch is to balance the condition scope between hci_get_cmd_complete and
hci_event_packet about orig_skb as follows:

if (req_complete_skb || event == HCI_EV_CMD_STATUS ||
event == HCI_EV_CMD_COMPLETE)
orig_skb = skb_clone(skb, GFP_KERNEL);

And hci_get_cmd_complete will bt_dev_err out when HCI_EV_CMD_STATUS, so a lot
of asymmetric conditions are triggered. Since both of them are the entry into
hci_get_cmd_complete, we'd better get STATUS into judge the false out there.

Signed-off-by: Zumeng Chen <[email protected]>
---

Hi expert,

This issue existed whether or not T_DBG had been changed into bt_dev_err, which
just shows the issue explicitly. I noticed actually that opcode doesn't match
ev->opcode either at the same time. And there might be some logic issue about
HCI_EV_CMD_COMPLETE between protocol and drivers. I'm not familar with the whole
bluetooth protocol, and not gonna to dig more, so all yours guys~

Cheers,
Zumeng

net/bluetooth/hci_event.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 235b5aa..d848663 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -5217,7 +5217,8 @@ static bool hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode,
return true;
}

- if (hdr->evt != HCI_EV_CMD_COMPLETE) {
+ if (!((hdr->evt == HCI_EV_CMD_COMPLETE) ||
+ (hdr->evt == HCI_EV_CMD_STATUS))) {
bt_dev_err(hdev, "last event is not cmd complete (0x%2.2x)",
hdr->evt);
return false;
--
2.7.4



2018-11-14 07:55:14

by Marcel Holtmann

[permalink] [raw]
Subject: Re: [PATCH 1/1] Bluetooth: make the balance of judgement condition to fix a false report

Hi Zumeng,

> This patch is to balance the condition scope between hci_get_cmd_complete and
> hci_event_packet about orig_skb as follows:
>
> if (req_complete_skb || event == HCI_EV_CMD_STATUS ||
> event == HCI_EV_CMD_COMPLETE)
> orig_skb = skb_clone(skb, GFP_KERNEL);
>
> And hci_get_cmd_complete will bt_dev_err out when HCI_EV_CMD_STATUS, so a lot
> of asymmetric conditions are triggered. Since both of them are the entry into
> hci_get_cmd_complete, we'd better get STATUS into judge the false out there.
>
> Signed-off-by: Zumeng Chen <[email protected]>
> ---
>
> Hi expert,
>
> This issue existed whether or not T_DBG had been changed into bt_dev_err, which
> just shows the issue explicitly. I noticed actually that opcode doesn't match
> ev->opcode either at the same time. And there might be some logic issue about
> HCI_EV_CMD_COMPLETE between protocol and drivers. I'm not familar with the whole
> bluetooth protocol, and not gonna to dig more, so all yours guys~
>
> Cheers,
> Zumeng
>
> net/bluetooth/hci_event.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 235b5aa..d848663 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -5217,7 +5217,8 @@ static bool hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode,
> return true;
> }
>
> - if (hdr->evt != HCI_EV_CMD_COMPLETE) {
> + if (!((hdr->evt == HCI_EV_CMD_COMPLETE) ||
> + (hdr->evt == HCI_EV_CMD_STATUS))) {

this indentation is messed up. Also some braces are not needed.

if (!(hdr->evt == HCI_EV_CMD_COMPLETE ||
hdr->evt == HCI_EV_CMD_STATUS)) {

> bt_dev_err(hdev, "last event is not cmd complete (0x%2.2x)",
> hdr->evt);
> return false;

Regards

Marcel


2018-11-15 01:35:13

by Zumeng Chen

[permalink] [raw]
Subject: [PATCH 1/1 v2] Bluetooth: make the balance of judgement condition to fix a false report

This patch is to balance the condition scope between hci_get_cmd_complete and
hci_event_packet about orig_skb as follows:

if (req_complete_skb || event == HCI_EV_CMD_STATUS ||
event == HCI_EV_CMD_COMPLETE)
orig_skb = skb_clone(skb, GFP_KERNEL);

And hci_get_cmd_complete will bt_dev_err out when HCI_EV_CMD_STATUS, so a lot
of asymmetric conditions are triggered. Since both of them are the entry into
hci_get_cmd_complete, we'd better get STATUS into judge the false out there.

Signed-off-by: Zumeng Chen <[email protected]>
---

v2: remove redundant braces and adjust the indentation.

Cheers,
Zumeng

net/bluetooth/hci_event.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 235b5aa..1d2a8fe 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -5217,7 +5217,8 @@ static bool hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode,
return true;
}

- if (hdr->evt != HCI_EV_CMD_COMPLETE) {
+ if (!(hdr->evt == HCI_EV_CMD_COMPLETE ||
+ hdr->evt == HCI_EV_CMD_STATUS)) {
bt_dev_err(hdev, "last event is not cmd complete (0x%2.2x)",
hdr->evt);
return false;
--
2.7.4


2018-11-26 11:26:15

by Luiz Augusto von Dentz

[permalink] [raw]
Subject: Re: [PATCH 1/1 v2] Bluetooth: make the balance of judgement condition to fix a false report

Hi Marcel,
On Thu, Nov 15, 2018 at 3:37 AM Zumeng Chen <[email protected]> wrote:
>
> This patch is to balance the condition scope between hci_get_cmd_complete and
> hci_event_packet about orig_skb as follows:
>
> if (req_complete_skb || event == HCI_EV_CMD_STATUS ||
> event == HCI_EV_CMD_COMPLETE)
> orig_skb = skb_clone(skb, GFP_KERNEL);
>
> And hci_get_cmd_complete will bt_dev_err out when HCI_EV_CMD_STATUS, so a lot
> of asymmetric conditions are triggered. Since both of them are the entry into
> hci_get_cmd_complete, we'd better get STATUS into judge the false out there.
>
> Signed-off-by: Zumeng Chen <[email protected]>
> ---
>
> v2: remove redundant braces and adjust the indentation.
>
> Cheers,
> Zumeng
>
> net/bluetooth/hci_event.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 235b5aa..1d2a8fe 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -5217,7 +5217,8 @@ static bool hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode,
> return true;
> }
>
> - if (hdr->evt != HCI_EV_CMD_COMPLETE) {
> + if (!(hdr->evt == HCI_EV_CMD_COMPLETE ||
> + hdr->evt == HCI_EV_CMD_STATUS)) {
> bt_dev_err(hdev, "last event is not cmd complete (0x%2.2x)",
> hdr->evt);
> return false;
> --
> 2.7.4

It appears we need this also for enabling vendor_diag with intel controllers:

[399314.236288] hci_cmd_status_evt:3138: hci0 opcode 0xfc43
[399314.236291] Bluetooth: hci0: last event is not cmd complete (0x0f)
[399314.236359] Bluetooth: hci0: Changing Intel diagnostic mode failed (-16)


--
Luiz Augusto von Dentz