On Mon, 25 Aug 2025 15:46:02 -0700 Stanislav Fomichev wrote:

quoted

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skb_frag_address can return NULL for unreadable frags.  

Is it safe to assume that drivers will ensure frags to be readable? It
seems at least mlx5 does.

I did a quick check and found other xdp kfuncs using
skb_frag_address() without checking the return.  

The unreadable frags will always be unredabale to the host. This is TCP
device memory, the memory on the accelerators that is not mapped onto
the CPU. Any attempts to read that memory should gracefully error out.

Can you also pls fix that other one? (not as part of the series should
be ok)

But we don't support mixing XDP with unreadable mem today.
Is the concern just for future proofing?