[PATCH] arm64: bpf: fix JIT stack setup

Shi, Yang yang.shi at linaro.org
Tue Nov 10 11:46:42 PST 2015

On 11/9/2015 12:00 PM, Z Lim wrote:
> On Mon, Nov 9, 2015 at 10:08 AM, Shi, Yang <yang.shi at linaro.org> 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 again for tracking this down and improving things overall for arm64 :)
>> Thanks,
>> Yang

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