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[0/2] Bluetooth: Avoid centralized adv handle tracking for extended features

Message ID 20210405233305.92431-1-danielwinkler@google.com
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Series Bluetooth: Avoid centralized adv handle tracking for extended features | expand

Message

Daniel Winkler April 5, 2021, 11:33 p.m. UTC 
Hi Maintainers,

This series addresses a race condition where an advertisement
registration can conflict with a software rotation advertisement
refresh. I found that this issue was only occurring with the new
extended MGMT advertising interface. A bad use of the
hdev->cur_adv_instance caused every new instance to be immediately sent
to the controller rather than queued for software rotation, opening a
path for the race to occur.

This series improves the way new extended advertising hci callbacks
track the relevant adv handle, removing the need for the
cur_adv_instance use. In a separate patch, the incorrect usage of
cur_adv_instance is removed, to align the extended MGMT commands to the
original add_advertising usage. The series was tested on both extended
and non-extended bluetooth controllers to confirm that the race
condition is resolved, and that multi- and single-advertising automated
test scenarios are still successful.

Thanks in advance,
Daniel


Daniel Winkler (2):
  Bluetooth: Use ext adv handle from requests in CCs
  Bluetooth: Do not set cur_adv_instance in adv param MGMT request

 net/bluetooth/hci_event.c | 16 +++++++---------
 net/bluetooth/mgmt.c      |  1 -
 2 files changed, 7 insertions(+), 10 deletions(-)

Comments

Marcel Holtmann April 6, 2021, 8:44 a.m. UTC | #1 
Hi Daniel,

> This series addresses a race condition where an advertisement

> registration can conflict with a software rotation advertisement

> refresh. I found that this issue was only occurring with the new

> extended MGMT advertising interface. A bad use of the

> hdev->cur_adv_instance caused every new instance to be immediately sent

> to the controller rather than queued for software rotation, opening a

> path for the race to occur.

> 

> This series improves the way new extended advertising hci callbacks

> track the relevant adv handle, removing the need for the

> cur_adv_instance use. In a separate patch, the incorrect usage of

> cur_adv_instance is removed, to align the extended MGMT commands to the

> original add_advertising usage. The series was tested on both extended

> and non-extended bluetooth controllers to confirm that the race

> condition is resolved, and that multi- and single-advertising automated

> test scenarios are still successful.

> 

> Thanks in advance,

> Daniel

> 

> 

> Daniel Winkler (2):

>  Bluetooth: Use ext adv handle from requests in CCs

>  Bluetooth: Do not set cur_adv_instance in adv param MGMT request

> 

> net/bluetooth/hci_event.c | 16 +++++++---------

> net/bluetooth/mgmt.c      |  1 -

> 2 files changed, 7 insertions(+), 10 deletions(-)


both patches have been applied to bluetooth-next tree.

Regards

Marcel