linux-kernel - Re: [PATCH mm-new 2/3] mm: clean up and expose is_guard_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] [day] [month] [year] [list]

Message-ID: <ee7e0841-e9b6-4a91-8b6c-43252432516c@redhat.com>
Date: Wed, 17 Sep 2025 12:32:22 +0200
From: David Hildenbrand <david@...hat.com>
To: Lance Yang <lance.yang@...ux.dev>, akpm@...ux-foundation.org,
 lorenzo.stoakes@...cle.com
Cc: ziy@...dia.com, baolin.wang@...ux.alibaba.com, Liam.Howlett@...cle.com,
 npache@...hat.com, ryan.roberts@....com, dev.jain@....com,
 baohua@...nel.org, ioworker0@...il.com, linux-kernel@...r.kernel.org,
 linux-mm@...ck.org, Kairui Song <kasong@...cent.com>
Subject: Re: [PATCH mm-new 2/3] mm: clean up and expose is_guard_pte_marker()

On 14.09.25 16:35, Lance Yang wrote:
> From: Lance Yang <lance.yang@...ux.dev>
> 
> is_guard_pte_marker() performs a redundant check because it calls both
> is_pte_marker() and is_guard_swp_entry(), both of which internally check
> for a PTE marker.
> 
> is_guard_pte_marker()
>   |- is_pte_marker()
>   |   `- is_pte_marker_entry()  // First check
>   `- is_guard_swp_entry()
>       `- is_pte_marker_entry()  // Second, redundant check
> 
> While a modern compiler could likely optimize this away, let's have clean
> code and not rely on it ;)
> 
> Also, make it available for hugepage collapsing code.
> 
> Cc: Kairui Song <kasong@...cent.com>
> Signed-off-by: Lance Yang <lance.yang@...ux.dev>
> ---

Acked-by: David Hildenbrand <david@...hat.com>

-- 
Cheers

David / dhildenb