Re: [RFC bpf-next 8/9] libbpf: support llvm-generated indirect jumps

[Eduard Zingerman <eddyz87@gmail.com>]

On Mon, 2025-07-07 at 17:49 -0700, Alexei Starovoitov wrote:
> On Mon, Jul 7, 2025 at 5:18 PM Eduard Zingerman <eddyz87@gmail.com> wrote:
> > 
> > On Mon, 2025-07-07 at 17:12 -0700, Alexei Starovoitov wrote:
> > 
> > [...]
> > 
> > > > check_cfg(), right, thank you.
> > > > But still, this feels like an artificial limitation.
> > > > Just because we have a check_cfg() pass as a separate thing we need
> > > > this hint.
> > > 
> > > and insn_successors().
> > > All of them have to work before the main verifier analysis.
> > 
> > Yeah, I see.
> > In theory, it shouldn't be hard to write a reaching definitions
> > analysis and make it do an additional pass once a connection between
> > gotox and a map is established.  And have this run before main
> > verification pass.
> 
> Yes. In theory :) But we don't have it today.
> Hence I don't understand the pushback to llvm-aid.
> If/when such dataflow analysis is available, we can drop llvm-aid.

No pushback, I forgot about changes needed in check_cfg() + I need to
rant a bit.