Re: [PATCH bpf-next v2 4/4] selftest: bpf: Test copying a sockmap and sockhash

[Martin KaFai Lau]

On Tue, Sep 29, 2020 at 10:21:05AM +0100, Lorenz Bauer wrote:
> On Tue, 29 Sep 2020 at 07:06, Martin KaFai Lau <kafai@xxxxxx> wrote:
> 
> ...
> 
> > > +     /* We need a temporary buffer on the stack, since the verifier doesn't
> > > +      * let us use the pointer from the context as an argument to the helper.
> > Is it something that can be improved later?
> >
> > others LGTM.
> 
> Yeah, I think so. We'd need to do something similar to your
> sock_common work for PTR_TO_RDONLY_BUF_OR_NULL. The fact that the
> pointer is read only makes it a bit more difficult I think. After
I thought the key arg should be used as read-only in the map's helper.
or there is map type's helper that modifies the key?

> that, a user could just plug the key into map_update_elem directly.
> Alternatively, allow specialising map_ops per context.