Re: [kernel-hardening] Re: x86: PIE support and option to extend KASLR randomization

From: Rik van Riel
Date: Tue Aug 15 2017 - 09:42:49 EST


On Tue, 2017-08-15 at 08:15 -0400, Jordan Glover wrote:
> Hello,
> I write to put different perspective into the topic. I'm glad that
> kernel developers care about performance optimizations and I see how
> 10% overhead can be a problem for some. On the other hand last ten
> years gave us 1000% faster hardware which trumps anything software
> can do. For many users like us performance isn't a problem, we have
> plenty of it and if we haven't we can buy it. It can be money
> problem, not software engineering problem.

CPUs stopped getting faster at a dramatic rate, though,
while network cards continue to get faster.

In some areas, the kernel is more squeezed for CPU cycles
today than it has ever been before.

Ingo is suggesting that the security enhancement be
implemented in a way that doesn't come with a 10% performance
gain. There are other ways to relocate a kernel than with PIE.