Re: [dpdk-dev] [PATCH 2/2] app/testpmd: fix hot-unplug detaching

[Kevin Traynor <ktraynor@redhat.com>]

On 16/02/2020 09:47, Thomas Monjalon wrote:
> 16/02/2020 09:09, Matan Azrad:
>> Hi Thomas
>>
>> Thanks for the patches, I Saw it just now.
>>  please see small comment below:
>>
>>  From: Thomas Monjalon
>>> There is a possible race condition in the hotplug path in rmv_port_callback().
>>> If a port is created between
>>> close_port(port_id) and detach_port_device(port_id), then the port_id will
>>> have been reallocated to a different device which will be wrongly detached.
>>>
>>> Since a check was added in detach_port_device() for manual detach case,
>>> the hotplug path was even more broken.
>>> It became impossible to run because the new check prevented to run
>>> detach_port_device() after the port is closed.
>>>
>>> The solution for both issues is to not rely on the port_id for detaching the
>>> rte_device.
>>> The function detach_port_device() is split to allow calling
>>> detach_device() directly with the rte_device pointer, saved before closing
>>> the port.
>>>
>>> Fixes: 43d0e304980a ("app/testpmd: fix invalid port detaching")
>>
>> If you fix the race, Don't you think you need to add fixes line for the patch which created the race?
> 
> Yes, you're right, I forgot it.
> It is too late now unfortunately, but we may request to backport it
> properly in 18.11 as well.
> 
> Please Kevin, add this tag so it will be part of 18.11:
> 
> Fixes: cbb4c648c5df ("ethdev: use device handle to detach")
> 

Ack. Will adjust the tag when applying, thanks.

>>> Cc: stable@dpdk.org
> 
> 
>