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bd7d30bd1d
Add explicit padding before launch_time so xsk_tx_metadata has the same
layout on 32-bit and 64-bit systems.
On several architectures (csky, i386, nios2, m65k, openrisc, sh), the old
native 32-bit layout put launch_time at offset 12 and had a natural size of
20 bytes. Using sizeof(struct xsk_tx_metadata) as tx_metadata_len was already
rejected because the length must be a multiple of eight, so the
straightforward use of the interface was broken on those ABIs. Userspace
could still register a padded length of 24 bytes, though; mixing the old and
new layouts then silently reads launch_time from the wrong offset and
misprograms packet launch times. This intentionally replaces that
incompatible layout because the affected architectures are unlikely to
have any notable users. (x86_64 and arm64 have the most users and are _not_
affected)
Fixes: ca4419f15a ("xsk: Add launch time hardware offload support to XDP Tx metadata")
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260819160535.1472459-2-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>