xsk: Require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len

[ Upstream commit d5e726d914 ]

Julian reports that commit 341ac980ea ("xsk: Support tx_metadata_len")
can break existing use cases which don't zero-initialize xdp_umem_reg
padding. Introduce new XDP_UMEM_TX_METADATA_LEN to make sure we
interpret the padding as tx_metadata_len only when being explicitly
asked.

Fixes: 341ac980ea ("xsk: Support tx_metadata_len")
Reported-by: Julian Schindel <mail@arctic-alpaca.de>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20240713015253.121248-2-sdf@fomichev.me
Signed-off-by: Sasha Levin <sashal@kernel.org>

This commit is contained in:

Stanislav Fomichev

2024-07-12 18:52:51 -07:00

committed by

Greg Kroah-Hartman

parent ec4eea14d7

commit 35dd37536e

3 changed files with 20 additions and 9 deletions

									
										include/uapi/linux/if_xdp.h
									
		+4
		
												View File
												
				@@ -41,6 +41,10 @@

				 */

				#define XDP_UMEM_TX_SW_CSUM		(1 << 1)

				/* Request to reserve tx_metadata_len bytes of per-chunk metadata.

				 */

				#define XDP_UMEM_TX_METADATA_LEN	(1 << 2)

				struct sockaddr_xdp {

					__u16 sxdp_family;

					__u16 sxdp_flags;