linux-kernel - Re: [PATCH v5 2/2] mm/arm64: override mkold_clean

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date: Fri, 12 Apr 2024 12:21:22 +0100
From: Ryan Roberts <ryan.roberts@....com>
To: Lance Yang <ioworker0@...il.com>
Cc: akpm@...ux-foundation.org, david@...hat.com, 21cnbao@...il.com,
 mhocko@...e.com, fengwei.yin@...el.com, zokeefe@...gle.com,
 shy828301@...il.com, xiehuan09@...il.com, wangkefeng.wang@...wei.com,
 songmuchun@...edance.com, peterx@...hat.com, minchan@...nel.org,
 linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 2/2] mm/arm64: override mkold_clean_ptes() batch helper

On 12/04/2024 03:09, Lance Yang wrote:
> On Thu, Apr 11, 2024 at 9:17 PM Ryan Roberts <ryan.roberts@....com> wrote:
>>
>> On 08/04/2024 05:24, Lance Yang wrote:
>>> The per-pte get_and_clear/modify/set approach would result in
>>> unfolding/refolding for contpte mappings on arm64. So we need
>>> to override mkold_clean_ptes() for arm64 to avoid it.
>>
>> IIRC, in the last version, I suggested copying the wrprotect_ptes() pattern to
>> correctly iterate over contpte blocks. I meant for you to take it as inspiration
>> but looks like you have done a carbon copy, including lots of things that are
>> unneeded here. That's my fault for not being clear - sorry!
> 
> My bad. I must have misunderstood your intention.

Not at all - it was my bad. wrprotect_ptes() is nothing like what I eventually
suggested below, so sorry for the bad steer.