Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> writes: > On Thu, Feb 1, 2024 at 2:56 AM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: >> >> > will be destroyed. So we implemented mixing bpf2bpf and tailcalls >> > similar to x86_64, i.e. using a non-callee saved register to transfer > ... >> Iiuc, this still needs a respin as per the ongoing discussions. Also, >> if you have worked on BPF selftests which exercise the corner case >> around a6, please include them in the series as well for coverage. > > Hold on, folks. > I'm not sure it's such a code idea to support tailcalls from subprogs > in risc-v. > They're broken on x86-64 and so far several attempts to fix them > were not successful. > If we don't have a fix soon we will disable this feature completely > in the verifier. > In general tailcalling from subprogs is a niche use case. > If there are users they should transition to tail call from main prog only. > > See > https://lore.kernel.org/bpf/CAADnVQJ1szry9P00wweVDu4d0AQoM_49qT-_ueirvggAiCZrpw@xxxxxxxxxxxxxx/ Got it. ...and it's broken on arm64 as well?
