From: Jesper Dangaard Brouer <[email protected]>
Date: Fri, 28 Apr 2017 16:25:04 +0200
> The struct bpf_map_def was extended in commit fb30d4b71214 ("bpf: Add tests
> for map-in-map") with member unsigned int inner_map_idx. This changed the
> size
> of the maps section in the generated ELF _kern.o files.
>
> Unfortunately the loader in bpf_load.c does not detect or handle this. Thus,
> older _kern.o files became incompatible, and caused hard-to-debug errors
> where the syscall validation rejected BPF_MAP_CREATE request.
>
> This patch only detect the situation and aborts load_bpf_file(). It also
> add code comments warning people that read this loader for inspiration
> for these pitfalls.
>
> Fixes: fb30d4b71214 ("bpf: Add tests for map-in-map")
> Signed-off-by: Jesper Dangaard Brouer <[email protected]>
Applied.
