From: Simon Horman <horms@kernel.org>
To: Stanislav Fomichev <sdf.kernel@gmail.com>
Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, anthony.l.nguyen@intel.com,
przemyslaw.kitszel@intel.com, andrew+netdev@lunn.ch,
saeedm@nvidia.com, tariqt@nvidia.com, mbloch@nvidia.com,
maxime.chevallier@bootlin.com, mcoquelin.stm32@gmail.com,
alexandre.torgue@foss.st.com, aleksander.lobakin@intel.com,
magnus.karlsson@intel.com, maciej.fijalkowski@intel.com,
sdf@fomichev.me, ast@kernel.org, daniel@iogearbox.net,
hawk@kernel.org, john.fastabend@gmail.com, witu@nvidia.com,
martin.lau@kernel.org, yoong.siang.song@intel.com,
rohan.g.thomas@intel.com, intel-wired-lan@lists.osuosl.org,
linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org, bpf@vger.kernel.org,
leon@kernel.org
Subject: Re: [PATCH net v2 1/3] xsk: align TX metadata layout across ABIs
Date: Mon, 17 Aug 2026 11:17:20 +0100 [thread overview]
Message-ID: <20260817101720.GX265046@horms.kernel.org> (raw)
In-Reply-To: <20260813190800.222527-2-sdf@fomichev.me>
On Thu, Aug 13, 2026 at 12:07:58PM -0700, Stanislav Fomichev wrote:
> Add explicit padding before launch_time so xsk_tx_metadata has the same
> layout on 32-bit and 64-bit systems.
>
> On i386 and m68k, 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 while the interface is still new.
>
> Fixes: ca4419f15abd ("xsk: Add launch time hardware offload support to XDP Tx metadata")
> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Simon Horman <horms@kernel.org>
WARNING: multiple messages have this Message-ID (diff)
From: Simon Horman <horms@kernel.org>
To: Stanislav Fomichev <sdf.kernel@gmail.com>
Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, anthony.l.nguyen@intel.com,
przemyslaw.kitszel@intel.com, andrew+netdev@lunn.ch,
saeedm@nvidia.com, tariqt@nvidia.com, mbloch@nvidia.com,
maxime.chevallier@bootlin.com, mcoquelin.stm32@gmail.com,
alexandre.torgue@foss.st.com, aleksander.lobakin@intel.com,
magnus.karlsson@intel.com, maciej.fijalkowski@intel.com,
sdf@fomichev.me, ast@kernel.org, daniel@iogearbox.net,
hawk@kernel.org, john.fastabend@gmail.com, witu@nvidia.com,
martin.lau@kernel.org, yoong.siang.song@intel.com,
rohan.g.thomas@intel.com, intel-wired-lan@lists.osuosl.org,
linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org, bpf@vger.kernel.org,
leon@kernel.org
Subject: Re: [Intel-wired-lan] [PATCH net v2 1/3] xsk: align TX metadata layout across ABIs
Date: Mon, 17 Aug 2026 11:17:20 +0100 [thread overview]
Message-ID: <20260817101720.GX265046@horms.kernel.org> (raw)
In-Reply-To: <20260813190800.222527-2-sdf@fomichev.me>
On Thu, Aug 13, 2026 at 12:07:58PM -0700, Stanislav Fomichev wrote:
> Add explicit padding before launch_time so xsk_tx_metadata has the same
> layout on 32-bit and 64-bit systems.
>
> On i386 and m68k, 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 while the interface is still new.
>
> Fixes: ca4419f15abd ("xsk: Add launch time hardware offload support to XDP Tx metadata")
> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Simon Horman <horms@kernel.org>
next prev parent reply other threads:[~2026-08-17 10:17 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-13 19:07 [PATCH net v2 0/3] xsk: pre-existing AF_XDP TX metadata fixes from Sashiko Stanislav Fomichev
2026-08-13 19:07 ` [Intel-wired-lan] " Stanislav Fomichev
2026-08-13 19:07 ` [PATCH net v2 1/3] xsk: align TX metadata layout across ABIs Stanislav Fomichev
2026-08-13 19:07 ` [Intel-wired-lan] " Stanislav Fomichev
2026-08-17 10:17 ` Simon Horman [this message]
2026-08-17 10:17 ` Simon Horman
2026-08-17 12:59 ` Arnd Bergmann
2026-08-17 12:59 ` [Intel-wired-lan] " Arnd Bergmann
2026-08-13 19:07 ` [Intel-wired-lan] [PATCH net v2 2/3] xsk: honor XDP_TX_METADATA in zero-copy path Stanislav Fomichev
2026-08-13 19:07 ` Stanislav Fomichev
2026-08-13 19:08 ` [Intel-wired-lan] [PATCH net v2 3/3] net: stmmac: skip queueMaxSDU check for AF_XDP Stanislav Fomichev
2026-08-13 19:08 ` Stanislav Fomichev
2026-08-17 10:17 ` Simon Horman
2026-08-17 10:17 ` [Intel-wired-lan] " Simon Horman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260817101720.GX265046@horms.kernel.org \
--to=horms@kernel.org \
--cc=aleksander.lobakin@intel.com \
--cc=alexandre.torgue@foss.st.com \
--cc=andrew+netdev@lunn.ch \
--cc=anthony.l.nguyen@intel.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=hawk@kernel.org \
--cc=intel-wired-lan@lists.osuosl.org \
--cc=john.fastabend@gmail.com \
--cc=kuba@kernel.org \
--cc=leon@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
--cc=linux-stm32@st-md-mailman.stormreply.com \
--cc=maciej.fijalkowski@intel.com \
--cc=magnus.karlsson@intel.com \
--cc=martin.lau@kernel.org \
--cc=maxime.chevallier@bootlin.com \
--cc=mbloch@nvidia.com \
--cc=mcoquelin.stm32@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=przemyslaw.kitszel@intel.com \
--cc=rohan.g.thomas@intel.com \
--cc=saeedm@nvidia.com \
--cc=sdf.kernel@gmail.com \
--cc=sdf@fomichev.me \
--cc=tariqt@nvidia.com \
--cc=witu@nvidia.com \
--cc=yoong.siang.song@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.