netdev - Re: [PATCH net] net: mscc: ocelot: install MAC addresses in .ndo_set_rx

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ae82dc10-11af-e48a-a317-fc60cda3b993@gmail.com>
Date:   Fri, 4 Dec 2020 09:34:54 -0800
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Vladimir Oltean <vladimir.oltean@....com>,
        "David S . Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>
Cc:     netdev@...r.kernel.org, UNGLinuxDriver@...rochip.com,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Horatiu Vultur <horatiu.vultur@...rochip.com>,
        "Allan W . Nielsen" <allan.nielsen@...rochip.com>,
        Claudiu Manoil <claudiu.manoil@....com>,
        Steen Hegelund <steen.hegelund@...rochip.com>
Subject: Re: [PATCH net] net: mscc: ocelot: install MAC addresses in
 .ndo_set_rx_mode from process context



On 12/4/2020 9:09 AM, Vladimir Oltean wrote:
> Currently ocelot_set_rx_mode calls ocelot_mact_learn directly, which has
> a very nice ocelot_mact_wait_for_completion at the end. Introduced in
> commit 639c1b2625af ("net: mscc: ocelot: Register poll timeout should be
> wall time not attempts"), this function uses readx_poll_timeout which
> triggers a lot of lockdep warnings and is also dangerous to use from
> atomic context, leading to lockups and panics.
> 
> Steen Hegelund added a poll timeout of 100 ms for checking the MAC
> table, a duration which is clearly absurd to poll in atomic context.
> So we need to defer the MAC table access to process context, which we do
> via a dynamically allocated workqueue which contains all there is to
> know about the MAC table operation it has to do.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@....com>

Reviewed-by: Florian Fainelli <f.fainelli@...il.com>

Did you want to have a Fixes tag to help identify how far back this
needs to be back ported?
-- 
Florian