> On Fri, 2023-07-21 at 18:19 +0200, Jose E. Marchesi wrote: >> Hi Yonghong. >> >> This is from the v4 instructions proposal: >> >> ======== ===== ========================= ============ >> code value description notes >> ======== ===== ========================= ============ >> BPF_JA 0x00 PC += imm BPF_JMP32 only >> >> Is this instruction using source 1 instead of 0? Otherwise, it would >> have exactly the same encoding than the V3< JA instruction. Is that >> what is intended? >> >> TIA. >> > > Hi Jose, > > I think that assumption is that `BPF_JMP32 | BPF_JA` is currently free: > - documentation [1] implies that only `BPF_JMP` should be used for `BPF_JA` > (see "notes" column for the first line) > - BPF verifier rejects `BPF_JMP32 | BPF_JA` > - clang always generates `BPF_JMP | BPF_JA` Makes sense, thanks for the info. Do you know the precise pseudo-c assembly syntax to use for this instruction? > Thanks, > Eduard > > [1] https://www.kernel.org/doc/html/latest/bpf/instruction-set.html#jump-instructions
