remove set_fs for riscv

[Christoph Hellwig]

On Mon, Sep 07, 2020 at 12:14:59AM +0200, Arnd Bergmann wrote:
> I've had a first pass at this now, see
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=arm-kill-set_fs
> 
> There are a couple of things in there that ended up uglier than I was
> hoping for, and it's completely untested beyond compilation. Is this
> roughly what you had in mind? I can do some testing then and post
> it to the Arm mailing list.

Looks sensible.  The OABI hacks a are a little ugly, but so would be
every other alternative.

Note that you don't need to add a TASK_SIZE_MAX definition to arm if you
base it on my series as that provides a default one.  I also think with
these changes arm/nommu should be able to use UACCESS_MEMCPY.