Re: [RFC PATCH bpf 1/6] bpf: Disallow interpreter fallback for user BPF_ADDR_SPACE_CAST insn

[Leon Hwang]

On 1/7/26 09:26, Tiezhu Yang wrote:
[...]
> 
> Hi all,
> 
> Alexei said in another thread like this:
> 
> ```
>> [3] https://lore.kernel.org/bpf/20260615025316.24429-1-
> yangtiezhu@xxxxxxxxxxx/
> 
> I don't think we need such fallback in patch [3].
> ```
> https://lore.kernel.org/bpf/DJMRIZ5PDWP4.12OOZ8H881H6O@xxxxxxxxx/
> 
> Should I just drop my previous patch? To be honest, I'm not sure how to
> solve the issue mentioned in it. Is that a real problem, and does it
> need to be fixed? What is the next step?
> 

It is a real issue.

Instead of fixing up helper calls, it seems better to prevent
interpreter fallback if the prog has any JIT-inlineable helper call.

Thanks,
Leon