From: "Jason A. Donenfeld" <Jason@xxxxxxxxx> Date: Thu, 3 Nov 2016 08:24:57 +0100 > Hi Herbert, > > On Thu, Nov 3, 2016 at 1:49 AM, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote: >> FWIW I'd rather live with a 6% slowdown than having two different >> code paths in the generic code. Anyone who cares about 6% would >> be much better off writing an assembly version of the code. > > Please think twice before deciding that the generic C "is allowed to > be slow". In any event no piece of code should be doing 32-bit word reads from addresses like "x + 3" without, at a very minimum, going through the kernel unaligned access handlers. Yet that is what the generic C poly1305 code is doing, all over the place. We know explicitly that these offsets will not be 32-bit aligned, so it is required that we use the helpers, or alternatively do things to avoid these unaligned accesses such as using temporary storage when the HAVE_EFFICIENT_UNALIGNED_ACCESS kconfig value is not set. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
