netdev - Re: [PATCH net-next v2 1/3] net: add check for current MAC address in dev_set_mac

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Message-ID: <99cc9c67-4027-70f8-3ff5-ab5ed5f8be73@intel.com>
Date: Tue, 20 Jun 2023 18:23:56 +0200
From: Piotr Gardocki <piotrx.gardocki@...el.com>
To: Jakub Kicinski <kuba@...nel.org>, Gal Pressman <gal@...dia.com>
CC: <netdev@...r.kernel.org>, <intel-wired-lan@...ts.osuosl.org>,
	<przemyslaw.kitszel@...el.com>, <michal.swiatkowski@...ux.intel.com>,
	<pmenzel@...gen.mpg.de>, <maciej.fijalkowski@...el.com>,
	<anthony.l.nguyen@...el.com>, <simon.horman@...igine.com>,
	<aleksander.lobakin@...el.com>
Subject: Re: [PATCH net-next v2 1/3] net: add check for current MAC address in
 dev_set_mac_address

On 20.06.2023 17:59, Jakub Kicinski wrote:
> On Tue, 20 Jun 2023 13:42:14 +0300 Gal Pressman wrote:
>>> I checked it, you're right. When the addr_assign_type is PERM or RANDOM
>>> and user or some driver sets the same MAC address the type doesn't change
>>> to NET_ADDR_SET. In my testing I didn't notice issues with that, but I'm
>>> sure there are cases I didn't cover. Did you discover any useful cases
>>> that broke after this patch or did you just notice it in code?  
>>
>> This behavior change was caught in our regression tests.
> 
> Why was the regression test written this way?
> 
> I guess we won't flip it back to PERM if user sets a completely
> different address temporarily and then back to PERM - so for consistency
> going to SET even when the addr doesn't change may be reasonable.
> 
> Piotr, you'll need to send a new followup patch on top of net-next.

Thanks, I'll prepare, test and send new patch tomorrow.