Re: [PATCH v2 2/5] objtool: Fix ORC unwinding in non-JIT BPF generated code

From: Alexei Starovoitov
Date: Fri Jun 14 2019 - 20:12:50 EST


On Fri, Jun 14, 2019 at 5:02 PM Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
>
> On Fri, Jun 14, 2019 at 04:30:15PM -0700, Alexei Starovoitov wrote:
> > On Fri, Jun 14, 2019 at 4:17 PM Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> > >
> > > On Fri, Jun 14, 2019 at 02:22:59PM -0700, Alexei Starovoitov wrote:
> > > > On Fri, Jun 14, 2019 at 2:19 PM Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> > > > > > > > >
> > > > > > > > > +#define JUMP_TABLE_SYM_PREFIX "jump_table."
> > > > > > > >
> > > > > > > > since external tool will be looking at it should it be named
> > > > > > > > "bpf_jump_table." to avoid potential name conflicts?
> > > > > > > > Or even more unique name?
> > > > > > > > Like "bpf_interpreter_jump_table." ?
> > > > > > >
> > > > > > > No, the point is that it's a generic feature which can also be used any
> > > > > > > non-BPF code which might also have a jump table.
> > > > > >
> > > > > > and you're proposing to name all such jump tables in the kernel
> > > > > > as static foo jump_table[] ?
> > > > >
> > > > > That's the idea.
> > > >
> > > > Then it needs much wider discussion.
> > >
> > > Why would it need wider discussion? It only has one user. If you
> > > honestly believe that it will be controversial to require future users
> > > to call a static jump table "jump_table" then we can have that
> > > discussion when it comes up.
> >
> > It's clearly controversial.
> > I nacked it already on pointless name change
> > from "jumptable" to "jump_table" and now you're saying
> > that no one will complain about "jump_table" name
> > for all jump tables in the kernel that will ever appear?
>
> Let me get this straight. You're saying that "jumptable" and
> "bpf_interpreter_jump_table" are both acceptable.
>
> But NACK to "jump_table".
>
> Ok...

Correct. I think I explained the reasons behind, right?