Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2023-03-23

We've added 8 non-merge commits during the last 13 day(s) which contain
a total of 21 files changed, 238 insertions(+), 161 deletions(-).

The main changes are:

1) Fix verification issues in some BPF programs due to their stack usage
   patterns, from Eduard Zingerman.

2) Fix to add missing overflow checks in xdp_umem_reg and return an error
   in such case, from Kal Conley.

3) Fix and undo poisoning of strlcpy in libbpf given it broke builds for
   libcs which provided the former like uClibc-ng, from Jesus Sanchez-Palencia.

4) Fix insufficient bpf_jit_limit default to avoid users running into hard
   to debug seccomp BPF errors, from Daniel Borkmann.

5) Fix driver return code when they don't support a bpf_xdp_metadata kfunc
   to make it unambiguous from other errors, from Jesper Dangaard Brouer.

6) Two BPF selftest fixes to address compilation errors from recent changes
   in kernel structures, from Alexei Starovoitov.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  xdp: bpf_xdp_metadata use EOPNOTSUPP for no driver support
  bpf: Adjust insufficient default bpf_jit_limit
  xsk: Add missing overflow check in xdp_umem_reg
  selftests/bpf: Fix progs/test_deny_namespace.c issues.
  selftests/bpf: Fix progs/find_vma_fail1.c build error.
  libbpf: Revert poisoning of strlcpy
  selftests/bpf: Tests for uninitialized stack reads
  bpf: Allow reads from uninit stack
====================

Link: https://lore.kernel.org/r/20230323225221.6082-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst
index aac63fc2d08b..25ce72af81c2 100644
--- a/Documentation/networking/xdp-rx-metadata.rst
+++ b/Documentation/networking/xdp-rx-metadata.rst
@@ -23,10 +23,13 @@ metadata is supported, this set will grow:
 An XDP program can use these kfuncs to read the metadata into stack
 variables for its own consumption. Or, to pass the metadata on to other
 consumers, an XDP program can store it into the metadata area carried
-ahead of the packet.
+ahead of the packet. Not all packets will necessary have the requested
+metadata available in which case the driver returns ``-ENODATA``.
 
 Not all kfuncs have to be implemented by the device driver; when not
-implemented, the default ones that return ``-EOPNOTSUPP`` will be used.
+implemented, the default ones that return ``-EOPNOTSUPP`` will be used
+to indicate the device driver have not implemented this kfunc.
+
 
 Within an XDP frame, the metadata layout (accessed via ``xdp_buff``) is
 as follows::