BPF_R1
BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
BPF_R1 = r1; \