Re: [bpf-next v8 0/5] emit ENDBR/BTI instructions for indirect jump targets

[Xu Kuohai]

On 3/10/2026 1:34 AM, Anton Protopopov wrote:
> On 26/03/09 10:00PM, Xu Kuohai wrote:
> > On architectures with CFI protection enabled that require landing pad
> > instructions at indirect jump targets, such as x86 with CET/IBT eanbled
>                                                                    ^ enabled
> > and arm64 with BTI enabled, kernel panics when an indirect jump lands on
> > a target witout landing pad. Therefore, the JIT must emit landing pad
>             ^ without
> > instructions for indirect jump targets.
> >
> > The verifier already recognizes which instructions are indirect jump
> > targets during the verification phase. So we can stores this information
>                                                     ^ store
> > in env->insn_aux_data and pass it to the JIT as new parameter, so the JIT
> > knows which instructions are indirect jump targets.
> >
> > During JIT, constants blinding is performed. It rewrites the private copy
> > of instructions for the JITed program, but it does not adjust the global
> > env->insn_aux_data array. As a result, after constants blinding, the
> > instruction indexes used by JIT may no longer match the indexes in
> > env->insn_aux_data, so the JIT can not lookup env->insn_aux_data directly.
> >
> > To avoid this mistach, and considering that all existing arch-specific JITs
>                  ^ mismatch?

I'll fix them and run a spelling check before sending the next version, thanks.