Hi Daniel, On Thu, Jun 30, 2022 at 11:12:54PM +0200, Daniel Borkmann wrote: > On 6/25/22 6:12 PM, Xu Kuohai wrote: > > This patchset introduces bpf trampoline on arm64. A bpf trampoline converts > > native calling convention to bpf calling convention and is used to implement > > various bpf features, such as fentry, fexit, fmod_ret and struct_ops. > > > > The trampoline introduced does essentially the same thing as the bpf > > trampoline does on x86. > > > > Tested on raspberry pi 4b and qemu: > > > > #18 /1 bpf_tcp_ca/dctcp:OK > > #18 /2 bpf_tcp_ca/cubic:OK > > #18 /3 bpf_tcp_ca/invalid_license:OK > > #18 /4 bpf_tcp_ca/dctcp_fallback:OK > > #18 /5 bpf_tcp_ca/rel_setsockopt:OK > > #18 bpf_tcp_ca:OK > > #51 /1 dummy_st_ops/dummy_st_ops_attach:OK > > #51 /2 dummy_st_ops/dummy_init_ret_value:OK > > #51 /3 dummy_st_ops/dummy_init_ptr_arg:OK > > #51 /4 dummy_st_ops/dummy_multiple_args:OK > > #51 dummy_st_ops:OK > > #57 /1 fexit_bpf2bpf/target_no_callees:OK > > #57 /2 fexit_bpf2bpf/target_yes_callees:OK > > #57 /3 fexit_bpf2bpf/func_replace:OK > > #57 /4 fexit_bpf2bpf/func_replace_verify:OK > > #57 /5 fexit_bpf2bpf/func_sockmap_update:OK > > #57 /6 fexit_bpf2bpf/func_replace_return_code:OK > > #57 /7 fexit_bpf2bpf/func_map_prog_compatibility:OK > > #57 /8 fexit_bpf2bpf/func_replace_multi:OK > > #57 /9 fexit_bpf2bpf/fmod_ret_freplace:OK > > #57 fexit_bpf2bpf:OK > > #237 xdp_bpf2bpf:OK > > > > v6: > > - Since Mark is refactoring arm64 ftrace to support long jump and reduce the > > ftrace trampoline overhead, it's not clear how we'll attach bpf trampoline > > to regular kernel functions, so remove ftrace related patches for now. > > - Add long jump support for attaching bpf trampoline to bpf prog, since bpf > > trampoline and bpf prog are allocated via vmalloc, there is chance the > > distance exceeds the max branch range. > > - Collect ACK/Review-by, not sure if the ACK and Review-bys for bpf_arch_text_poke() > > should be kept, since the changes to it is not trivial > > - Update some commit messages and comments > > Given you've been taking a look and had objections in v5, would be great if you > can find some cycles for this v6. Mark's out at the moment, so I wouldn't hold this series up pending his ack. However, I agree that it would be good if _somebody_ from the Arm side can give it the once over, so I've added Jean-Philippe to cc in case he has time for a quick review. KP said he would also have a look, as he is interested in this series landing. Failing that, I'll try to look this week, but I'm off next week and I don't want this to miss the merge window on my account. Cheers, Will
