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

Daniel Borkmann says:

====================
pull-request: bpf 2021-11-16

We've added 12 non-merge commits during the last 5 day(s) which contain
a total of 23 files changed, 573 insertions(+), 73 deletions(-).

The main changes are:

1) Fix pruning regression where verifier went overly conservative rejecting
   previsouly accepted programs, from Alexei Starovoitov and Lorenz Bauer.

2) Fix verifier TOCTOU bug when using read-only map's values as constant
   scalars during verification, from Daniel Borkmann.

3) Fix a crash due to a double free in XSK's buffer pool, from Magnus Karlsson.

4) Fix libbpf regression when cross-building runqslower, from Jean-Philippe Brucker.

5) Forbid use of bpf_ktime_get_coarse_ns() and bpf_timer_*() helpers in tracing
   programs due to deadlock possibilities, from Dmitrii Banshchikov.

6) Fix checksum validation in sockmap's udp_read_sock() callback, from Cong Wang.

7) Various BPF sample fixes such as XDP sta...