Re: [PATCH v2] igc: fix page fault in XDP TX timestamps handling

[Florian Bezdeka]

On Wed, 2026-02-25 at 10:58 +0100, Zdenek Bouska wrote:
> If an XDP application that requested TX timestamping is shutting down
> while the link of the interface in use is still up the following kernel
> splat is reported:
> 
> [  883.803618] [   T1554] BUG: unable to handle page fault for address: ffffcfb6200fd008
> ...
> [  883.803650] [   T1554] Call Trace:
> [  883.803652] [   T1554]  <TASK>
> [  883.803654] [   T1554]  igc_ptp_tx_tstamp_event+0xdf/0x160 [igc]
> [  883.803660] [   T1554]  igc_tsync_interrupt+0x2d5/0x300 [igc]
> ...
> 
> During shutdown of the TX ring the xsk_meta pointers are left behind, so
> that the IRQ handler is trying to touch them.
> 
> This issue is now being fixed by cleaning up the stale xsk meta data on
> TX shutdown. TX timestamps on other queues remain unaffected.
> 
> Fixes: 15fd021bc427 ("igc: Add Tx hardware timestamp request for AF_XDP zero-copy packet")
> Signed-off-by: Zdenek Bouska <zdenek.bouska@xxxxxxxxxxx>
> ---
> Changes in v2:
> - Moved 'adapter' variable declaration into the if block (Vinicius)
> - Link to v1: https://lore.kernel.org/r/20260224-igc-fix-xdp-tx-tstamp-pagefault-v1-1-7c729ef61ee5@xxxxxxxxxxx
> ---

Reviewed-by: Florian Bezdeka <florian.bezdeka@xxxxxxxxxxx>