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` Thanks, Eduard [1] https://www.kernel.org/doc/html/latest/bpf/instruction-set.html#jump-instructions
