On Tue, May 02, 2017 at 02:31:56PM +0200, Jesper Dangaard Brouer wrote:
> This patch does proper parsing of the ELF "maps" section, in-order to
> be both backwards and forwards compatible with changes to the map
> definition struct bpf_map_def, which gets compiled into the ELF file.
>
> The assumption is that new features with value zero, means that they
> are not in-use. For backward compatibility where loading an ELF file
> with a smaller struct bpf_map_def, only copy objects ELF size, leaving
> rest of loaders struct zero. For forward compatibility where ELF file
> have a larger struct bpf_map_def, only copy loaders own struct size
> and verify that rest of the larger struct is zero, assuming this means
> the newer feature was not activated, thus it should be safe for this
> older loader to load this newer ELF file.
>
> Fixes: fb30d4b71214 ("bpf: Add tests for map-in-map")
> Fixes: 409526bea3c3 ("samples/bpf: bpf_load.c detect and abort if ELF maps
> section size is wrong")
> Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com>
I would just merge patches 2 and 3 to reduce churn,
but it looks like great improvement already.
Acked-by: Alexei Starovoitov <a...@kernel.org>
