Re: [PATCH] crypto: add key wrapping block chaining mode

[Stephan Mueller <smueller@chronox.de>]

Am Donnerstag, 23. April 2015, 09:39:28 schrieb Herbert Xu:

Hi Herbert,

> On Wed, Apr 22, 2015 at 02:44:08PM +0200, Stephan Mueller wrote:
> > > Where does this 8-byte alignment requirement come from?
> > 
> > Well, I am accessing the data in 8-byte chunks. Moreover, in the
> > scatterwalk copy functions, I search through the scatterlists in 8 byte
> > increments. If, say, a scatterwalk is not a multiple of 8 bytes, the
> > scatterwalk logic will not process the last chunk of memory.
> 
> Alignment refers to whether the address can handle a load of a
> given size by the CPU, it does not mean that the length will
> be a multiple of the alignment.  Alignment is only required if
> you do a load of the given size.
> 
> For example if you read a u64 then on many architectures that
> will require an alignment of 8.  Vice versa if you only do byte
> loads then you do not need to specify the alignment.
> 
> I don't see any u64 loads in your code.

Ok, I will remove it.
> 
> Cheers,


-- 
Ciao
Stephan