Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 31 Oct 2018 13:38:37 -0700
From: Andy Lutomirski <>
To: Peter Zijlstra <>
Cc: Igor Stoppa <>,
 Matthew Wilcox <>, Tycho Andersen <>,
 Kees Cook <>, Mimi Zohar <>,
 Dave Chinner <>, James Morris <>,
 Michal Hocko <>,
 Kernel Hardening <>,
 linux-integrity <>,
 linux-security-module <>,
 Igor Stoppa <>,
 Dave Hansen <>,
 Jonathan Corbet <>, Laura Abbott <>,
 Randy Dunlap <>,
 Mike Rapoport <>,
 "open list:DOCUMENTATION" <>,
 LKML <>, Thomas Gleixner <>
Subject: Re: [PATCH 10/17] prmem: documentation

> On Oct 31, 2018, at 3:11 AM, Peter Zijlstra <> wrote:
>> On Wed, Oct 31, 2018 at 12:15:46AM +0200, Igor Stoppa wrote:
>> On 30/10/2018 23:02, Andy Lutomirski wrote:
>>> But I dislike allowing regular writes in the protected region. We
>>> really only need four write primitives:
>>> 1. Just write one value.  Call at any time (except NMI).
>>> 2. Just copy some bytes. Same as (1) but any number of bytes.
>>> 3,4: Same as 1 and 2 but must be called inside a special rare write
>>> region. This is purely an optimization.
>> Atomic? RCU?
> RCU can be done, that's not really a problem. Atomics otoh are a
> problem. Having pointers makes them just work.
> Andy; I understand your reason for not wanting them, but I really don't
> want to duplicate everything. Is there something we can do with static
> analysis to make you more comfortable with the pointer thing?

I’m sure we could do something with static analysis, but I think seeing a real use case where all this fanciness makes sense would be good.

And I don’t know if s390 *can* have an efficient implementation that uses pointers. OTOH they have all kinds of magic stuff, so who knows?

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.