On Thu, Nov 2, 2023 at 6:44 AM Vadim Fedorenko <vadim.fedorenko@xxxxxxxxx> wrote: > > On 01/11/2023 23:41, Martin KaFai Lau wrote: > > On 11/1/23 3:50 PM, Vadim Fedorenko wrote: > >>>> +static void *__bpf_dynptr_data_ptr(const struct bpf_dynptr_kern *ptr) > >>>> +{ > >>>> + enum bpf_dynptr_type type; > >>>> + > >>>> + if (!ptr->data) > >>>> + return NULL; > >>>> + > >>>> + type = bpf_dynptr_get_type(ptr); > >>>> + > >>>> + switch (type) { > >>>> + case BPF_DYNPTR_TYPE_LOCAL: > >>>> + case BPF_DYNPTR_TYPE_RINGBUF: > >>>> + return ptr->data + ptr->offset; > >>>> + case BPF_DYNPTR_TYPE_SKB: > >>>> + return skb_pointer_if_linear(ptr->data, ptr->offset, > >>>> __bpf_dynptr_size(ptr)); > >>>> + case BPF_DYNPTR_TYPE_XDP: > >>>> + { > >>>> + void *xdp_ptr = bpf_xdp_pointer(ptr->data, ptr->offset, > >>>> __bpf_dynptr_size(ptr)); > >>> > >>> I suspect what it is doing here (for skb and xdp in particular) is > >>> very similar to bpf_dynptr_slice. Please check if > >>> bpf_dynptr_slice(ptr, 0, NULL, sz) will work. > >>> > >> > >> Well, yes, it's simplified version of bpf_dynptr_slice. The problem is > >> that bpf_dynptr_slice bpf_kfunc which cannot be used in another > >> bpf_kfunc. Should I refactor the code to use it in both places? Like > > > > Sorry, scrolled too fast in my earlier reply :( > > > > I am not aware of this limitation. What error does it have? > > The bpf_dynptr_slice_rdwr kfunc() is also calling the bpf_dynptr_slice() > > kfunc. > > > >> create __bpf_dynptr_slice() which will be internal part of bpf_kfunc? > > Apparently Song has a patch to expose these bpf_dynptr_slice* functions > ton in-kernel users. > > https://lore.kernel.org/bpf/20231024235551.2769174-2-song@xxxxxxxxxx/ > > Should I wait for it to be merged before sending next version? If you need something from another developer it's best to ask them explicitly :) In this case Song can respin with just that change that you need.