Re: [PATCH bpf-next 2/3] bpf: mark bpf_cast_to_kern_ctx and bpf_rdonly_cast as KF_NOCSR

[Eduard Zingerman <eddyz87@gmail.com>]

On Thu, 2024-08-15 at 14:25 -0700, Andrii Nakryiko wrote:
> On Mon, Aug 12, 2024 at 4:44 PM Eduard Zingerman <eddyz87@gmail.com> wrote:
> > 
> > do_misc_fixups() relaces bpf_cast_to_kern_ctx() and bpf_rdonly_cast()
> > by a single instruction "r0 = r1". This clearly follows nocsr contract.
> > Mark these two functions as KF_NOCSR, in order to use them in
> > selftests checking KF_NOCSR behaviour for kfuncs.
> > 
> > Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
> > ---
> >  kernel/bpf/helpers.c  | 4 ++--
> >  kernel/bpf/verifier.c | 3 ++-
> >  2 files changed, 4 insertions(+), 3 deletions(-)
> 
> Isn't it now "bpf fastcall" and not "nocsr"? Shouldn't the flag and
> verifier code reflect this updated terminology?

Here is a pull request for LLVM that lands the feature under
the new bpf_fastcall name: https://github.com/llvm/llvm-project/pull/101228
I hope that it would be approved today or tomorrow (more like tomorrow).

Kernel side uses NOCSR in all places.
I can add a first patch to the series, renaming all NOCSR to bpf_fastcall,
now that it looks like llvm upstream won't object the name.

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