[kernel PATCH v1 0/1] Fix get clock info

[kernel PATCH v1 0/1] Fix get clock info

[Zhengping Jiang]

Similar to get conn info function, the function to get clock info also
need to set connection data.

Fixes: 5a75013746640 ("Bluetooth: hci_sync: Convert MGMT_OP_GET_CLOCK_INFO")

Changes in v1:
- Fix input connection data

Zhengping Jiang (1):
  Bluetooth: Fix get clock info

 net/bluetooth/mgmt.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

-- 
2.37.0.170.g444d1eabd0-goog

[kernel PATCH v1 1/1] Bluetooth: Fix get clock info

[Zhengping Jiang]

If connection exists, set the connection data before calling
get_clock_info_sync, so it can be verified the connection is still
connected, before retrieving clock info.

Signed-off-by: Zhengping Jiang <jiangzp@google.com>
---

Changes in v1:
- Fix input connection data

 net/bluetooth/mgmt.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index ef8371975c4eb..947d700574c54 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -6971,11 +6971,16 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
 	}
 
 	cmd = mgmt_pending_new(sk, MGMT_OP_GET_CLOCK_INFO, hdev, data, len);
-	if (!cmd)
+	if (!cmd) {
 		err = -ENOMEM;
-	else
+	} else {
+		if (conn) {
+			hci_conn_hold(conn);
+			cmd->user_data = hci_conn_get(conn);
+		}
 		err = hci_cmd_sync_queue(hdev, get_clock_info_sync, cmd,
 					 get_clock_info_complete);
+	}
 
 	if (err < 0) {
 		err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_GET_CLOCK_INFO,
@@ -6984,12 +6989,8 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
 		if (cmd)
 			mgmt_pending_free(cmd);
 
-	} else if (conn) {
-		hci_conn_hold(conn);
-		cmd->user_data = hci_conn_get(conn);
 	}
 
-
 unlock:
 	hci_dev_unlock(hdev);
 	return err;
-- 
2.37.0.170.g444d1eabd0-goog

RE: Fix get clock info

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 1096 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=661636

---Test result---

Test Summary:
CheckPatch                    PASS      1.88 seconds
GitLint                       PASS      1.06 seconds
SubjectPrefix                 PASS      0.90 seconds
BuildKernel                   PASS      35.95 seconds
BuildKernel32                 PASS      30.80 seconds
Incremental Build with patchesPASS      42.99 seconds
TestRunner: Setup             PASS      517.95 seconds
TestRunner: l2cap-tester      PASS      17.38 seconds
TestRunner: bnep-tester       PASS      6.03 seconds
TestRunner: mgmt-tester       PASS      98.29 seconds
TestRunner: rfcomm-tester     PASS      9.52 seconds
TestRunner: sco-tester        PASS      9.18 seconds
TestRunner: smp-tester        PASS      9.26 seconds
TestRunner: userchan-tester   PASS      6.15 seconds



---
Regards,
Linux Bluetooth

Re: [kernel PATCH v1 1/1] Bluetooth: Fix get clock info

[Luiz Augusto von Dentz]

Hi Zhengping,

On Wed, Jul 20, 2022 at 4:36 PM Zhengping Jiang <jiangzp@google.com> wrote:
>
> If connection exists, set the connection data before calling
> get_clock_info_sync, so it can be verified the connection is still
> connected, before retrieving clock info.
>
> Signed-off-by: Zhengping Jiang <jiangzp@google.com>
> ---
>
> Changes in v1:
> - Fix input connection data
>
>  net/bluetooth/mgmt.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index ef8371975c4eb..947d700574c54 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -6971,11 +6971,16 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
>         }
>
>         cmd = mgmt_pending_new(sk, MGMT_OP_GET_CLOCK_INFO, hdev, data, len);
> -       if (!cmd)
> +       if (!cmd) {
>                 err = -ENOMEM;
> -       else
> +       } else {
> +               if (conn) {
> +                       hci_conn_hold(conn);
> +                       cmd->user_data = hci_conn_get(conn);
> +               }
>                 err = hci_cmd_sync_queue(hdev, get_clock_info_sync, cmd,
>                                          get_clock_info_complete);
> +       }

Having seconds though if this is actually the right thing to do,
hci_cmd_sync_queue will queue the command so get_clock_info_sync
shouldn't execute immediately if that happens that actually would be
quite a problem since we are holding the hci_dev_lock so if the
callback executes and blocks waiting a command that would likely cause
a deadlock because no command can be completed while hci_dev_lock is
being held, in fact I don't really like the idea of holding hci_conn
reference either since we are doing a lookup by address on
get_clock_info_sync Id probably just remove this code as it seem
unnecessary.

Btw, there are tests for this command in mgmt-tester so if this is
actually attempting to fix a problem Id like to have a test to
reproduce it.

>         if (err < 0) {
>                 err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_GET_CLOCK_INFO,
> @@ -6984,12 +6989,8 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
>                 if (cmd)
>                         mgmt_pending_free(cmd);
>
> -       } else if (conn) {
> -               hci_conn_hold(conn);
> -               cmd->user_data = hci_conn_get(conn);
>         }
>
> -
>  unlock:
>         hci_dev_unlock(hdev);
>         return err;
> --
> 2.37.0.170.g444d1eabd0-goog
>


-- 
Luiz Augusto von Dentz

Re: [kernel PATCH v1 1/1] Bluetooth: Fix get clock info

[Luiz Augusto von Dentz]

Hi Zhengping,

On Thu, Jul 21, 2022 at 3:20 PM Luiz Augusto von Dentz
<luiz.dentz@gmail.com> wrote:
>
> Hi Zhengping,
>
> On Wed, Jul 20, 2022 at 4:36 PM Zhengping Jiang <jiangzp@google.com> wrote:
> >
> > If connection exists, set the connection data before calling
> > get_clock_info_sync, so it can be verified the connection is still
> > connected, before retrieving clock info.
> >
> > Signed-off-by: Zhengping Jiang <jiangzp@google.com>
> > ---
> >
> > Changes in v1:
> > - Fix input connection data
> >
> >  net/bluetooth/mgmt.c | 13 +++++++------
> >  1 file changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> > index ef8371975c4eb..947d700574c54 100644
> > --- a/net/bluetooth/mgmt.c
> > +++ b/net/bluetooth/mgmt.c
> > @@ -6971,11 +6971,16 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
> >         }
> >
> >         cmd = mgmt_pending_new(sk, MGMT_OP_GET_CLOCK_INFO, hdev, data, len);
> > -       if (!cmd)
> > +       if (!cmd) {
> >                 err = -ENOMEM;
> > -       else
> > +       } else {
> > +               if (conn) {
> > +                       hci_conn_hold(conn);
> > +                       cmd->user_data = hci_conn_get(conn);
> > +               }
> >                 err = hci_cmd_sync_queue(hdev, get_clock_info_sync, cmd,
> >                                          get_clock_info_complete);
> > +       }
>
> Having seconds though if this is actually the right thing to do,
> hci_cmd_sync_queue will queue the command so get_clock_info_sync
> shouldn't execute immediately if that happens that actually would be
> quite a problem since we are holding the hci_dev_lock so if the
> callback executes and blocks waiting a command that would likely cause
> a deadlock because no command can be completed while hci_dev_lock is
> being held, in fact I don't really like the idea of holding hci_conn
> reference either since we are doing a lookup by address on
> get_clock_info_sync Id probably just remove this code as it seem
> unnecessary.
>
> Btw, there are tests for this command in mgmt-tester so if this is
> actually attempting to fix a problem Id like to have a test to
> reproduce it.

Looks at the other change you submitted that has a similar code
pattern I did the following change:

https://gist.github.com/Vudentz/91cd57373d5b0116e2c34b6fb6adaa07

And mgmt-tester seems to run just fine with these changes.

>
> >         if (err < 0) {
> >                 err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_GET_CLOCK_INFO,
> > @@ -6984,12 +6989,8 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
> >                 if (cmd)
> >                         mgmt_pending_free(cmd);
> >
> > -       } else if (conn) {
> > -               hci_conn_hold(conn);
> > -               cmd->user_data = hci_conn_get(conn);
> >         }
> >
> > -
> >  unlock:
> >         hci_dev_unlock(hdev);
> >         return err;
> > --
> > 2.37.0.170.g444d1eabd0-goog
> >
>
>
> --
> Luiz Augusto von Dentz



-- 
Luiz Augusto von Dentz

Re: [kernel PATCH v1 1/1] Bluetooth: Fix get clock info

[Zhengping Jiang]

Hi Luiz,

Thanks for the rework. This patch looks good. The function to get
connection info was causing test regression in some hardware
platforms, but not always. We don't currently have a test for getting
clock info here. I was submitting the patch because it is using the
same pattern as getting conn info.
I tested the new patch and it is working well, so we can abandon my patch.

Best,
Zhengping

On Thu, Jul 21, 2022 at 3:41 PM Luiz Augusto von Dentz
<luiz.dentz@gmail.com> wrote:
>
> Hi Zhengping,
>
> On Thu, Jul 21, 2022 at 3:20 PM Luiz Augusto von Dentz
> <luiz.dentz@gmail.com> wrote:
> >
> > Hi Zhengping,
> >
> > On Wed, Jul 20, 2022 at 4:36 PM Zhengping Jiang <jiangzp@google.com> wrote:
> > >
> > > If connection exists, set the connection data before calling
> > > get_clock_info_sync, so it can be verified the connection is still
> > > connected, before retrieving clock info.
> > >
> > > Signed-off-by: Zhengping Jiang <jiangzp@google.com>
> > > ---
> > >
> > > Changes in v1:
> > > - Fix input connection data
> > >
> > >  net/bluetooth/mgmt.c | 13 +++++++------
> > >  1 file changed, 7 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> > > index ef8371975c4eb..947d700574c54 100644
> > > --- a/net/bluetooth/mgmt.c
> > > +++ b/net/bluetooth/mgmt.c
> > > @@ -6971,11 +6971,16 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
> > >         }
> > >
> > >         cmd = mgmt_pending_new(sk, MGMT_OP_GET_CLOCK_INFO, hdev, data, len);
> > > -       if (!cmd)
> > > +       if (!cmd) {
> > >                 err = -ENOMEM;
> > > -       else
> > > +       } else {
> > > +               if (conn) {
> > > +                       hci_conn_hold(conn);
> > > +                       cmd->user_data = hci_conn_get(conn);
> > > +               }
> > >                 err = hci_cmd_sync_queue(hdev, get_clock_info_sync, cmd,
> > >                                          get_clock_info_complete);
> > > +       }
> >
> > Having seconds though if this is actually the right thing to do,
> > hci_cmd_sync_queue will queue the command so get_clock_info_sync
> > shouldn't execute immediately if that happens that actually would be
> > quite a problem since we are holding the hci_dev_lock so if the
> > callback executes and blocks waiting a command that would likely cause
> > a deadlock because no command can be completed while hci_dev_lock is
> > being held, in fact I don't really like the idea of holding hci_conn
> > reference either since we are doing a lookup by address on
> > get_clock_info_sync Id probably just remove this code as it seem
> > unnecessary.
> >
> > Btw, there are tests for this command in mgmt-tester so if this is
> > actually attempting to fix a problem Id like to have a test to
> > reproduce it.
>
> Looks at the other change you submitted that has a similar code
> pattern I did the following change:
>
> https://gist.github.com/Vudentz/91cd57373d5b0116e2c34b6fb6adaa07
>
> And mgmt-tester seems to run just fine with these changes.
>
> >
> > >         if (err < 0) {
> > >                 err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_GET_CLOCK_INFO,
> > > @@ -6984,12 +6989,8 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
> > >                 if (cmd)
> > >                         mgmt_pending_free(cmd);
> > >
> > > -       } else if (conn) {
> > > -               hci_conn_hold(conn);
> > > -               cmd->user_data = hci_conn_get(conn);
> > >         }
> > >
> > > -
> > >  unlock:
> > >         hci_dev_unlock(hdev);
> > >         return err;
> > > --
> > > 2.37.0.170.g444d1eabd0-goog
> > >
> >
> >
> > --
> > Luiz Augusto von Dentz
>
>
>
> --
> Luiz Augusto von Dentz