# Re: skb\_splice\_bits() and large chunks in pipe (was Re: xfs\_file\_splice\_read: possible circular locking dependency detected

- From: Herbert Xu \<herbert@gondor.apana.org.au\>
- Date: 2016-09-20 09:51:22 
- List: netdev
- Page: https://ratatoskr.run/netdev/2016/09/112436
- Thread: https://ratatoskr.run/linux-fsdevel/2016/09/112441/t.md

```text
Al Viro [ref] wrote:
>
>        * shoved into scatterlist, which gets fed into crypto/*.c machinery.
> No way for a pipe_buffer stuff to get there, fortunately, because I would
> be very surprised if it works correctly with compound pages and large
> ranges in those.

FWIW the crypto API has always been supposed to handle SG entries
that cross page boundaries.  There were a couple of bugs in this
area but AFAIK they've all been fixed.

Of course I cannot guarantee that every crypto driver also handles
it correctly, but at least we have a few test vectors which test
the page-crossing case specifically.

Cheers,
-- 
Email: Herbert Xu [ref]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
```