Re: [PATCH 09/16] ps3disk: use memcpy_{from,to}_bvec

[Herbert Xu]

On Fri, Jun 11, 2021 at 09:07:43PM -0700, Ira Weiny wrote:
>
> More recently this was added:
> 
> 7e34e0bbc644 crypto: omap-crypto - fix userspace copied buffer access
> 
> I'm CC'ing Tero and Herbert to see why they added the SLAB check.

Probably because the generic Crypto API has the same check.  This
all goes back to

commit 4f3e797ad07d52d34983354a77b365dfcd48c1b4
Author: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Date:   Mon Feb 9 14:22:14 2009 +1100

    crypto: scatterwalk - Avoid flush_dcache_page on slab pages

    It's illegal to call flush_dcache_page on slab pages on a number
    of architectures.  So this patch avoids doing so if PageSlab is
    true.

    In future we can move the flush_dcache_page call to those page
    cache users that actually need it.

    Reported-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>

But I can't find any emails discussing this so let me ask Dave
directly and see if he can tell us what the issue was or might
have been.

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt