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authorJakub Kicinski <kuba@kernel.org>2023-03-23 16:03:33 -0700
committerJakub Kicinski <kuba@kernel.org>2023-03-23 16:03:33 -0700
commit1b4ae19e432dfec785d980993c09593cbb182754 (patch)
treeac92de509d9e09f042292218b03c2c551386b3f6 /Documentation
parent2e63a2dfe73fd00e48b615ef1274a44299f57c5f (diff)
parent915efd8a446b74442039d31689d5d863caf82517 (diff)
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>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/networking/xdp-rx-metadata.rst7
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::