Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Alexei Starovoitov says:

====================
pull-request: bpf 2021-01-07

We've added 4 non-merge commits during the last 10 day(s) which contain
a total of 4 files changed, 14 insertions(+), 7 deletions(-).

The main changes are:

1) Fix task_iter bug caused by the merge conflict resolution, from Yonghong.

2) Fix resolve_btfids for multiple type hierarchies, from Jiri.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpftool: Fix compilation failure for net.o with older glibc
  tools/resolve_btfids: Warn when having multiple IDs for single type
  bpf: Fix a task_iter bug caused by a merge conflict resolution
  selftests/bpf: Fix a compile error for BPF_F_BPRM_SECUREEXEC
====================

Link: https://lore.kernel.org/r/20210107221555.64959-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>