Re: [PATCH 3/4] sparc: fix accurate exception reporting in copy_{from_to}_user for Niagara

[Rene Rebe <rene@exactcode.com>]

From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

> On Tue, 2025-09-02 at 18:51 +0200, Rene Rebe wrote:
> > From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
> > 
> > > Hi Rene,
> > > 
> > > On Tue, 2025-09-02 at 18:40 +0200, Rene Rebe wrote:
> > > > Hi,
> > > > 
> > > > From: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
> > > > 
> > > > > Fixes: 7ae3aaf53f16 ("sparc64: Convert NGcopy_{from,to}_user to accurate exception reporting.")
> > > > > Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
> > > > 
> > > > Tested-by: René Rebe <rene@exactcode.com> # UltraSparc T4 SPARC T4-1 Server
> > > 
> > > Thanks for the testing! However, this actually needs to be tested on a SPARC T1
> > > as both T2 and T4 have their own implementation that is being used. Testing on a
> > > T4 will therefore not invoke this particular code unless you modify the kernel in
> > > head_64.S to employ the Niagara 1 code on Niagara 4.
> > 
> > Ah right, sorry, IIRC you wrote that :-/
> > 
> > > Do you happen to have a SPARC T1?
> > 
> > Unfortuantely not. A T2 user might have one, but I could also modify
> > the kernel and use the less optimized T1 code if that helps, ...
> 
> I have done that already to test the Niagara 1 code on Niagara 4.
> 
> However, it would be nice to test on a real T1. Unfortunately, I haven't found
> anyone yet who got one. If you could ask your users, that would be great.

someone in our Discord probably has one in the basement or attic, but
the chances of them turning just that system on the next days or weeks
is probably rather slim.

I guess testing all the "popular" systems: vintage collected
workstations and affortable more modern higher performance T4 servers
is all we got for the near future for this patches.

       René

> Otherwise, we will have to go with the current level of testing.
> 
> Adrian
> 
> -- 
>  .''`.  John Paul Adrian Glaubitz
> : :' :  Debian Developer
> `. `'   Physicist
>   `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

-- 
  René Rebe, ExactCODE GmbH, Berlin, Germany
  https://exactcode.com | https://t2linux.com | https://rene.rebe.de