netlink: specs: nlctrl: fix the policy attribute numbering

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mask and pad are declared the wrong way round, giving mask 11 and
pad 12, while enum netlink_policy_type_attr has
NL_POLICY_TYPE_ATTR_PAD at 11 and NL_POLICY_TYPE_ATTR_MASK at 12.

The kernel emits the mask for every NLA_POLICY_MASK() attribute, so a
Python YNL client parsing a policy dump maps it onto pad and throws it
away - 30 of them in ethtool's policy alone.  In the other direction the
64-bit alignment padding, which the kernel does emit on architectures
without efficient unaligned access, is decoded as a u64 mask and blows
up the whole dump. But those architectures are rare.

The generated C parser is not affected, it keys the attributes off the
uAPI symbol names rather than off the values the spec derives.

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20260916021516.1701760-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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Jakub Kicinski 2026-09-15 19:15:15 -07:00

parent 29f4b46371

commit 0fa13b71c3

1 changed files with 3 additions and 3 deletions

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Documentation/netlink/specs/nlctrl.yaml

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