On Fri, Jan 28, 2022 at 9:09 PM Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > On Fri, Jan 28, 2022 at 10:51 AM Matteo Croce > <mcroce@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Fri, Jan 28, 2022 at 6:31 AM Alexei Starovoitov > > <alexei.starovoitov@xxxxxxxxx> wrote: > > > > > > On Mon, Dec 20, 2021 at 10:34 PM Yonghong Song <yhs@xxxxxx> wrote: > > > > > > > > > > > > https://reviews.llvm.org/D116063 improved the error message as below > > > > to make it a little bit more evident what is the problem: > > > > > > > > $ clang -target bpf -O2 -g -c bug.c > > > > > > > > fatal error: error in backend: SubroutineType not supported for > > > > BTF_TYPE_ID_REMOTE reloc > > > > > > Hi Matteo, > > > > > > Are you still working on a test? > > > What's a timeline to repost the patch set? > > > > > > Thanks! > > > > Hi Alexei, > > > > The change itself is ready, I'm just stuck at writing a test which > > will effectively calls __bpf_core_types_are_compat() with some > > recursion. > > I guess that I have to generate a BTF_KIND_FUNC_PROTO type somehow, so > > __bpf_core_types_are_compat() is called again to check the prototipe > > arguments type. > > I tried with these two, with no luck: > > > > // 1 > > typedef int (*func_proto_typedef)(struct sk_buff *); > > bpf_core_type_exists(func_proto_typedef); > > > > // 2 > > void func_proto(int, unsigned int); > > bpf_core_type_id_kernel(func_proto); > > > > Which is a simple way to generate a BTF_KIND_FUNC_PROTO BTF field? > > What do you mean 'no luck'? > Have you tried what progs/test_core_reloc_type_id.c is doing? > typedef int (*func_proto_typedef)(long); > bpf_core_type_id_kernel(func_proto_typedef); > > Without macros: > typedef int (*func_proto_typedef)(long); > > int test() { > return __builtin_btf_type_id(*(typeof(func_proto_typedef) *)0, 1); > } > int test2() { > return __builtin_preserve_type_info(*(typeof(func_proto_typedef) *)0, 0); > } > > > compiles fine and generates relos. Yes, I tried that one. We reach bpf_core_apply_relo_insn() but not bpf_core_spec_match(), since cands->len is 0. [ 16.424821] bpf_core_apply_relo_insn:1202 cands->len: 0 That's a very simple raw_tracepoint/sys_enter program: -- per aspera ad upstream
