On Thu, May 21, 2026 at 9:00 PM Maciej Fijalkowski
[off-list ref] wrote:

On Thu, May 21, 2026 at 08:41:08PM +0800, Jason Xing wrote:

quoted

On Thu, May 21, 2026 at 8:24 PM Maciej Fijalkowski
[off-list ref] wrote:

quoted

On Wed, May 20, 2026 at 08:42:39AM +0800, Jason Xing wrote:

quoted

From: Jason Xing <kernelxing@tencent.com>

The series is the product of previous review from sashiko[1].

1) META
patch 1: address TOCTOU around metadata.

2) PUBLISH of CQ
patch 2: make sure xsk_addr->addrs[] can be published to cq when
         overflow occurs.
patch 3: keep cleaning up the continuation descs (more than 17) and
         publish its address when overflow occurs.
patch 4: like patch 3, but only handles the invalid descs cases.

[1]: https://lore.kernel.org/all/20260502200722.53960-1-kerneljasonxing@gmail.com/ (local)

---
V4
Link: https://lore.kernel.org/all/20260517063311.28921-1-kerneljasonxing@gmail.com/ (local)
1. correct the description of xmit path in patch 3 (sashiko)
2. move set logic into xmit path in patch 3 (Stan)

V3
Link: https://lore.kernel.org/all/20260515123018.80147-1-kerneljasonxing@gmail.com/ (local)
1. avoid breaking previous usage of sendto, and siliently handle
overflow case (Stan, sashiko)
2. add one particular exception process in patch 4 (sashiko)
3. adjust the selftest to make sure it passes in either virutal or
physical machines, which includes add usleep to support physical machine.

V2
Link: https://lore.kernel.org/all/20260510012310.88570-1-kerneljasonxing@gmail.com/ (local)
1. adjust selftests (Jakub)
2. add READ_ONCE in patch 1 (Stan)

FWIW I still get test failures (yes with patch 5 applied). PTAL.

Thanks for the test. But I've tried with ixgbe driver...

I noticed there are some flaky tests which have nothing to do with the
series. Can you confirm that it's not caused because of the series?

That explains the different results as i am using i40e/ice which have
multi-buffer support whereas ixgbe does not even support mbuf at XDP.
Broken tests are from mbuf cases.

That's weird. I never expected the failed tests to be about multi-buffer.

Are they the same as the output you attached last time? Or something
new? Could you please share it so that I can investigate the root
cause?

Thanks,
Jason

quoted

Thanks,
Jason

quoted

quoted

Jason Xing (5):
  xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()
  xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx
  xsk: drain continuation descs after overflow in xsk_build_skb()
  xsk: drain continuation descs on invalid descriptor in
    __xsk_generic_xmit()
  selftests/xsk: drain CQ to wait for TX completion

 include/net/xdp_sock.h                        |  1 +
 net/xdp/xsk.c                                 | 44 +++++++++++++----
 .../selftests/bpf/prog_tests/test_xsk.c       | 48 +++++++++++--------
 3 files changed, 63 insertions(+), 30 deletions(-)

--
2.43.7