Re: [PATCH net] net: bridge: fix ioctl old_deviceless bridge argument

Remi Pommarel
2021-12-23T13:28:47Z

On Thu, Dec 23, 2021 at 12:38:14PM +0100, Arnd Bergmann wrote:
> On Thu, Dec 23, 2021 at 12:00 PM Remi Pommarel <repk@triplefau.lt> wrote:
> >
> > On Wed, Dec 22, 2021 at 10:52:20PM +0100, Arnd Bergmann wrote:
> > > On Wed, Dec 22, 2021 at 8:13 PM Remi Pommarel <repk@triplefau.lt> wrote:
> > [...]
> > >
> > > The intention of my broken patch was to make it work for compat mode as I did
> > > in br_dev_siocdevprivate(), as this is now the only bit that remains broken.
> > >
> > > This could be done along the lines of the patch below, if you see any value in
> > > it. (not tested, probably not quite right).
> >
> > Oh ok, because SIOC{S,G}IFBR compat ioctl was painfully done with
> > old_bridge_ioctl() I didn't think those needed compat. So I adapted and
> > fixed your patch to get that working.
>
> Ok, thanks!
>
> > Here is my test results.
> >
> > With my initial patch only :
> > - 64bit busybox's brctl (working)
> > # brctl show
> > bridge name bridge id STP enabled interfaces
> > br0 8000.000000000000 n
> >
> > - CONFIG_COMPAT=y + 32bit busybox's brctl (not working)
> > # brctl show
> > brctl: SIOCGIFBR: Invalid argument
> >
> > With both my intial patch and the one below :
> > - 64bit busybox's brctl (working)
> > # brctl show
> > bridge name bridge id STP enabled interfaces
> > br0 8000.000000000000 n
> >
> > - CONFIG_COMPAT=y + 32bit busybox's brctl (working)
> > # brctl show
> > bridge name bridge id STP enabled interfaces
> > br0 8000.000000000000 n
> >
> > If you think this has enough value to fix those compatility issues I can
> > either send the below patch as a V2 replacing my initial one for net
> > or sending it as a separate patch for net-next. What would you rather
> > like ?
>
> If 32-bit busybox still uses those ioctls in moderately recent
> versions, then it's probably worth doing this, but that would
> be up to the bridge maintainers.
>
> Your patch looks good to me, I see you caught a few mistakes
> in my prototype. I would however suggest basing it on top of
> your original fix, so that can be applied first and backported
> to stable kernels, while the new patch would go on top and
> not get backported.
>
> If that works with everyone, please submit those two, and add
> these tags to the second patch:
>
> Co-developed-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Ok thanks a lot, will send a new patch serie with both patches so
that bridge maintainers could only pick one or both patches.

--
Remi