Re: [GIT PULL] x86/mm changes for v4.21

Peter Zijlstra
2019-02-07T14:01:52Z

On Thu, Feb 07, 2019 at 11:50:52AM +0000, Linus Torvalds wrote:
> If you re-generate the canonical address in __cpa_addr(), now we'll
> actually have the real virtual address around for a lot of code-paths
> (pte lookup etc), which was what people wanted to avoid in the first
> place.

Note that it's an 'unsigned long' address, not an actual pointer, and
(afaict) non of the code paths use it as a pointer. This _should_ avoid
the CPU from following said pointer and doing a deref on it.

But yes, I didn't go all the way down, maybe I missed some.