Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 23 May 2022 18:19:54 -0400 | From | Michael Mullin <> | Subject | Re: [PATCH] bpftool: mmaped fields missing map structure in generated skeletons |
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On Mon, May 23, 2022 at 03:02:31PM -0700, Andrii Nakryiko wrote: > On Mon, May 23, 2022 at 1:26 PM Michael Mullin <masmullin@gmail.com> wrote: > > > > When generating a skeleton which has an mmaped map field, bpftool's > > output is missing the map structure. This causes a compile break when > > the generated skeleton is compiled as the field belongs to the internal > > struct maps, not directly to the obj. > > > > Signed-off-by: Michael Mullin <masmullin@gmail.com> > > --- > > tools/bpf/bpftool/gen.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c > > index f158dc1c2149..b49293795ba0 100644 > > --- a/tools/bpf/bpftool/gen.c > > +++ b/tools/bpf/bpftool/gen.c > > @@ -853,7 +853,7 @@ codegen_maps_skeleton(struct bpf_object *obj, size_t map_cnt, bool mmaped) > > i, bpf_map__name(map), i, ident); > > /* memory-mapped internal maps */ > > if (mmaped && is_internal_mmapable_map(map, ident, sizeof(ident))) { > > - printf("\ts->maps[%zu].mmaped = (void **)&obj->%s;\n", > > + printf("\ts->maps[%zu].mmaped = (void **)&obj->maps.%s;\n", > > That's not right. maps.my_map is struct bpf_map *, but mmaped is > supposed to be a blob of memory that is memory-mapped into map. > > Can you elaborate on how you trigger that compilation error with a > small example?
I have an a very small example on github. I have added some sed fixes to my Makefile make my sample program compile. https://github.com/masmullin2000/libbpf-sample/tree/main/c/simple
https://github.com/masmullin2000/libbpf-sample/tree/02c7f945bf9027daedec04f485a320ba2df28204/c/simple contains broken code.
I apologize if this is an incorrect way to share external code. I haven't found the proper way to share example code from kernelnewbies.org
> > > i, ident); > > } > > i++; > > -- > > 2.36.1 > >
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