Re: [PATCH bpf-next 1/2] bpf, x86: patch tail-call fentry slot on non-IBT JITs

[Alexei Starovoitov]

On Fri, Mar 27, 2026 at 7:16 AM Takeru Hayasaka <hayatake396@xxxxxxxxx> wrote:
>
> x86 tail-call fentry patching mirrors CALL text pokes to the tail-call
> landing slot.
>
> The helper that locates that mirrored slot assumes an ENDBR-prefixed
> landing, which works on IBT JITs but fails on non-IBT JITs where the
> landing starts directly with the 5-byte patch slot.

tailcalls are deprecated. We should go the other way and
disable them ibt jit instead.
The less interaction between fentry and tailcall the better.

pw-bot: cr