Merge branch 'allow-bpf_map_sum_elem_count-for-all-program-types'

Merge branch 'allow-bpf_map_sum_elem_count-for-all-program-types'

Anton Protopopov says:

====================
allow bpf_map_sum_elem_count for all program types

This series is a follow up to the recent change [1] which added
per-cpu insert/delete statistics for maps. The bpf_map_sum_elem_count
kfunc presented in the original series was only available to tracing
programs, so let's make it available to all.

The first patch makes types listed in the reg2btf_ids[] array to be
considered trusted by kfuncs.

The second patch allows to treat CONST_PTR_TO_MAP as trusted pointers from
kfunc's point of view by adding it to the reg2btf_ids[] array.

The third patch adds missing const to the map argument of the
bpf_map_sum_elem_count kfunc.

The fourth patch registers the bpf_map_sum_elem_count for all programs,
and patches selftests correspondingly.

  [1] https://lore.kernel.org/bpf/20230705160139.19967-1-aspsk@isovalent.com/

v1 -> v2:
  * treat the whole reg2btf_ids array as trusted (Alexei)
====================

Link: https://lore.kernel.org/r/20230719092952.41202-1-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>