Date:   Thu, 23 Dec 2021 09:53:18 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Remi Pommarel <repk@triplefau.lt>
Cc:     netdev@vger.kernel.org, Roopa Prabhu <roopa@nvidia.com>,
        Nikolay Aleksandrov <nikolay@nvidia.com>,
        Arnd Bergmann <arnd@arndb.de>,
        "David S. Miller" <davem@davemloft.net>,
        bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net 2/2] net: bridge: Get SIOCGIFBR/SIOCSIFBR ioctl
 working in compat mode
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        <20211223085944.55b43857@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net>
        <YcS25oqoo+xnAIIW@pilgrim>
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On Thu, 23 Dec 2021 18:50:30 +0100 Remi Pommarel wrote:
> On Thu, Dec 23, 2021 at 08:59:44AM -0800, Jakub Kicinski wrote:
> > On Thu, 23 Dec 2021 16:31:39 +0100 Remi Pommarel wrote:  
> > > In compat mode SIOC{G,S}IFBR ioctls were only supporting
> > > BRCTL_GET_VERSION returning an artificially version to spur userland
> > > tool to use SIOCDEVPRIVATE instead. But some userland tools ignore that
> > > and use SIOC{G,S}IFBR unconditionally as seen with busybox's brctl.
> > > 
> > > Example of non working 32-bit brctl with CONFIG_COMPAT=y:
> > > $ brctl show
> > > brctl: SIOCGIFBR: Invalid argument
> > > 
> > > Example of fixed 32-bit brctl with CONFIG_COMPAT=y:
> > > $ brctl show
> > > bridge name     bridge id               STP enabled     interfaces
> > > br0
> > > 
> > > Signed-off-by: Remi Pommarel <repk@triplefau.lt>
> > > Co-developed-by: Arnd Bergmann <arnd@arndb.de>
> > > Signed-off-by: Arnd Bergmann <arnd@arndb.de>  
> > 
> > Since Arnd said this is not supposed to be backported I presume it
> > should go to net-next?  
> 
> Yes, out of curiosity, is it appropriate to mix "[PATCH net]" and
> "[PATCH net-next]" in the same serie ?

It's not, mixing makes it quite hard to know what's needed where.
Also hard to automate things on our end. Let me pick out the first
patch, I'll be sending a PR to Linus shortly and then merge net into
net-next. At which point you'll be able to rebase on top of net-next
and resend just the second patch for net-next..