Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model
From: Josh Poimboeuf <hidden>
Date: 2016-05-04 17:02:40
Also in:
linux-s390, lkml
From: Josh Poimboeuf <hidden>
Date: 2016-05-04 17:02:40
Also in:
linux-s390, lkml
On Wed, May 04, 2016 at 02:39:40PM +0200, Petr Mladek wrote:
On Thu 2016-04-28 15:44:48, Josh Poimboeuf wrote:quoted
Change livepatch to use a basic per-task consistency model. This is the foundation which will eventually enable us to patch those ~10% of security patches which change function or data semantics. This is the biggest remaining piece needed to make livepatch more generally useful.I spent a lot of time with checking the memory barriers. It seems that they are basically correct. Let me use my own words to show how I understand it. I hope that it will help others with review.
[...snip a ton of useful comments...] Thanks, this will help a lot! I'll try to incorporate your barrier comments into the code. I also agree that kpatch_patch_task() is poorly named. I was trying to make it clear to external callers that "hey, the task is getting patched now!", but it's internally inconsistent with livepatch code because we make a distinction between patching and unpatching. Maybe I'll do: klp_update_task_patch_state() -- Josh