Merge branch 'sample-bpf-loader-fixes'

Jesper Dangaard Brouer says:

====================
Improve bpf ELF-loader under samples/bpf

This series improves and fixes bpf ELF loader and programs under
samples/bpf.  The bpf_load.c created some hard to debug issues when
the struct (bpf_map_def) used in the ELF maps section format changed
in commit fb30d4b71214 ("bpf: Add tests for map-in-map").

This was hotfixed in commit 409526bea3c3 ("samples/bpf: bpf_load.c
detect and abort if ELF maps section size is wrong") by detecting the
issue and aborting the program.

In most situations the bpf-loader should be able to handle these kind
of changes to the struct size.  This patch series aim to do proper
backward and forward compabilility handling when loading ELF files.

This series also adjust the callback that was introduced in commit
9fd63d05f3e8 ("bpf: Allow bpf sample programs (*_user.c) to change
bpf_map_def") to use the new bpf_map_data structure, before more users
start to use this callback.

Hoping these changes can make the merge window, as above mentioned
commits have not been merged yet, and it would be good to avoid users
hitting these issues.
====================

Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>