Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Guo Ren]

On Tue, Feb 1, 2022 at 3:45 PM Christoph Hellwig <hch@xxxxxx> wrote:
>
> On Mon, Jan 31, 2022 at 09:50:58PM +0800, Guo Ren wrote:
> > On Mon, Jan 31, 2022 at 8:26 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> > >
> > > Given that most rv64 implementations can't run in rv32 mode, what is the
> > > failure mode if someone tries it with the compat mode enabled?
> > A static linked simple hello_world could still run on a non-compat
> > support hardware. But most rv32 apps would meet different userspace
> > segment faults.
> >
> > Current code would let the machine try the rv32 apps without detecting
> > whether hw support or not.
>
> Hmm, we probably want some kind of check for not even offer running
> rv32 binaries.  I guess trying to write UXL some time during early
> boot and catching the resulting exception would be the way to go?

Emm... I think it's unnecessary. Free rv32 app running won't cause
system problem, just as a wrong elf running. They are U-mode
privileged.
>
> >
> >
> > --
> > Best Regards
> >  Guo Ren
> >
> > ML: https://lore.kernel.org/linux-csky/
> ---end quoted text---



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/