Merge branch 'bpf-prog-map-ID'

Martin KaFai Lau says:

====================
Introduce bpf ID

This patch series:
1) Introduce ID for both bpf_prog and bpf_map.
2) Add bpf commands to iterate the prog IDs and map
   IDs of the system.
3) Add bpf commands to get a prog/map fd from an ID
4) Add bpf command to get prog/map info from a fd.
   The prog/map info is a jump start in this patchset
   and it is not meant to be a complete list.  They can
   be extended in the future patches.

v3:
- I suspect v2 may not have applied cleanly.
  In particular, patch 1 has conflict with a recent
  change in struct bpf_prog_aux introduced at a similar time frame:
  8726679a

 ("bpf: teach verifier to track stack depth")
  v3 should have fixed it.

v2:
Compiler warning fixes:
- Remove lockdep_is_held() usage.  Add comment
  to explain the lock situation instead.
- Add static for idr related variables
- Add __user to the uattr param in bpf_prog_get_info_by_fd()
  and bpf_map_get_info_by_fd().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>