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.
