Re: Smatch check for Spectre stuff

From: Gustavo A. R. Silva
Date: Mon Apr 23 2018 - 09:09:30 EST




On 04/23/2018 07:45 AM, Peter Zijlstra wrote:
On Mon, Apr 23, 2018 at 07:31:03AM -0500, Gustavo A. R. Silva wrote:
Hi Peter,

On 04/20/2018 07:00 AM, Peter Zijlstra wrote:

Hi Dan,

awesome stuff...

So I fear that many are actually things we want to fix. Our policy was
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store.

I wonder if there is any thread where I can read the discussion about that
policy that you mention.

Could you share it here, please?

I think it was somewhere in the many spectre variant1 threads when Linus
Alexei and Dan W were hashing out the mitigation thing. I cannot quickly
find the specific email.

Clarifying that position was one reason for the patches I did, Linus and
Dan W are on Cc and I figure that if they all agree we should maybe add
a little something to Documentation/speculation.txt.



Yeah. I think it's important to mention that, so everybody is on the same page. In particular now that is very likely that many people will start writing patches to fix the rest of the issues Dan reported.

Thanks
--
Gustavo