Re: [PATCH v11 1/2] crypto: AF_ALG: add AEAD support

From: Herbert Xu
Date: Sun Jan 25 2015 - 23:33:00 EST


On Mon, Jan 26, 2015 at 05:26:33AM +0100, Stephan Mueller wrote:
> Am Montag, 26. Januar 2015, 10:55:50 schrieb Herbert Xu:
>
> Hi Herbert,
>
> > On Wed, Jan 21, 2015 at 02:19:17AM +0100, Stephan Mueller wrote:
> > > + /* use the existing memory in an allocated page */
> > > + if (ctx->merge) {
> > > + sg = sgl->sg + sgl->cur - 1;
> > > + len = min_t(unsigned long, len,
> > > + PAGE_SIZE - sg->offset - sg->length);
> > > + err = memcpy_from_msg(page_address(sg_page(sg)) +
> > > + sg->offset + sg->length,
> > > + msg, len);
> > > + if (err)
> > > + goto unlock;
> > > +
> > > + sg->length += len;
> > > + ctx->merge = (sg->offset + sg->length) &
> > > + (PAGE_SIZE - 1);
> > > +
> > > + ctx->used += len;
> > > + copied += len;
> > > + size -= len;
> >
> > Need to add a continue here to recheck size != 0.
>
> Why would that be needed?
>
> When size is still != 0 (i.e. the existing buffer is completely filled, we
> have still some remaining data), we fall through to the while loop that
> generates a new buffer.

Because when size == 0 you should exit the loop. IOW if the new
data is completely merged you should get out and not continue.

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