Re: [PATCH] crypto: af_alg - add async support to algif_aead

[Tadeusz Struk]

Hi Stephan,
On 01/27/2016 10:26 PM, Stephan Mueller wrote:
>> +	for (i = 0; i < areq->tsgls; i++)
>> > +		put_page(sg_page(sg + i));
> Shouldn't here be the same logic as in put_sgl? I.e.
> 
>         for (i = 0; i < sgl->cur; i++) {
>                 if (!sg_page(sg + i))
>                         continue;
> 
>                 put_page(sg_page(sg + i));
>                 sg_assign_page(sg + i, NULL);
>         }
> 

Thanks for reviewing.
I don't think it is possible that there ever will be any gaps in the tsgl.
In fact if there is such a possibility then it is a serious problem, because
it would mean that we are sending NULL ptrs to the ciphers (see line 640):

	sg_mark_end(sgl->sg + sgl->cur - 1);
	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg,
			       used, ctx->iv);

I don't see any implementation checking for null in sgls. Most of them just do:

	for_each_sg(sgl, sg, nents, i)
		sg_virt(sg)...

So it would Oops there. I think this check in put_sgl is redundant.
Thanks,
-- 
TS