linux-kernel - Re: [PATCH RFC] mm: userfaultfd: correct dirty flags set for both present and swap pte

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

Message-ID: <aBzMf6H9Lad6CaFQ@x1.local>
Date: Thu, 8 May 2025 11:23:43 -0400
From: Peter Xu <peterx@...hat.com>
To: Barry Song <21cnbao@...il.com>
Cc: akpm@...ux-foundation.org, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, Barry Song <v-songbaohua@...o.com>,
	David Hildenbrand <david@...hat.com>,
	Suren Baghdasaryan <surenb@...gle.com>,
	Lokesh Gidra <lokeshgidra@...gle.com>
Subject: Re: [PATCH RFC] mm: userfaultfd: correct dirty flags set for both
 present and swap pte

On Thu, May 08, 2025 at 09:07:35PM +1200, Barry Song wrote:
> From: Barry Song <v-songbaohua@...o.com>
> 
> As David pointed out, what truly matters for mremap and userfaultfd
> move operations is the soft dirty bit. The current comment and
> implementation—which always sets the dirty bit for present PTEs
> and fails to set the soft dirty bit for swap PTEs—are incorrect.
> This patch updates the behavior to correctly set the soft dirty bit
> for both present and swap PTEs in accordance with mremap.
> 
> Reported-by: David Hildenbrand <david@...hat.com>
> Closes: https://lore.kernel.org/linux-mm/02f14ee1-923f-47e3-a994-4950afb9afcc@redhat.com/
> Cc: Peter Xu <peterx@...hat.com>
> Cc: Suren Baghdasaryan <surenb@...gle.com>
> Cc: Lokesh Gidra <lokeshgidra@...gle.com>
> Signed-off-by: Barry Song <v-songbaohua@...o.com>

Acked-by: Peter Xu <peterx@...hat.com>

-- 
Peter Xu