Re: [PATCH v3 1/2] bpf: Reject attaching fexit to functions annotated with __noreturn

[Yafang Shao <laoar.shao@xxxxxxxxx>]

On Wed, Feb 26, 2025 at 1:52 AM Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
>
> On Mon, Feb 24, 2025 at 07:46:05PM +0800, Yafang Shao wrote:
> > +BTF_SET_START(fexit_deny)
> > +#define NORETURN(fn) BTF_ID(func, fn)
> > +NORETURN(__fortify_panic)
> > +NORETURN(__ia32_sys_exit)
> > +NORETURN(__ia32_sys_exit_group)
>
> Why not just sync with the objtool noreturns.h?  Now we have two
> hard-coded lists instead of one.  These are guaranteed to diverge.

For details, refer to Alexei's response here:
https://lore.kernel.org/bpf/CAADnVQ+zLZKyrNGnGQDThasdS6cvM-FheN5Ttz23pF5ttbGasw@xxxxxxxxxxxxxx/.

We cannot simply reuse the objtool noreturns.h file because BTF is
limited to handling only existing functions.

--
Regards

Yafang