Re: [PATCH] arm64: bpf: fix JIT stack setup

[Shi, Yang]

On 11/9/2015 12:00 PM, Z Lim wrote:
> On Mon, Nov 9, 2015 at 10:08 AM, Shi, Yang <yang.shi@xxxxxxxxxx> wrote:
> > I added it to stay align with ARMv8 AAPCS to maintain the correct FP during
> > function call. It makes us get correct stack backtrace.
> >
> > I think we'd better to keep compliant with ARMv8 AAPCS in BPF JIT prologue
> > too.
> >
> > If nobody thinks it is necessary, we definitely could remove that change.
>
> Oh no, I don't think anyone will say it's unnecessary!
> I agree the A64_FP-related change is a good idea, so stack unwinding works.
>
> How about splitting this into two patches? One for the BPF-related
> bug, and another for A64 FP-handling.

I'm not sure if this is a good approach or not. IMHO, they are kind of 
atomic. Without A64 FP-handling, that fix looks incomplete and 
introduces another problem (stack backtrace).

Thanks,
Yang

> Thanks again for tracking this down and improving things overall for arm64 :)
>
> > Thanks,
> > Yang

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