linux-kernel - Re: [PATCH 05/21] x86/mm/pat: mirror direct map changes to ASI

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: <DFU660CYC3H5.3L7IVBXG8AIY1@google.com>
Date: Wed, 21 Jan 2026 09:45:22 +0000
From: Brendan Jackman <jackmanb@...gle.com>
To: Borislav Petkov <bp@...en8.de>, Brendan Jackman <jackmanb@...gle.com>
Cc: Dave Hansen <dave.hansen@...el.com>, Andy Lutomirski <luto@...nel.org>, 
	Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, "Liam R. Howlett" <Liam.Howlett@...cle.com>, 
	Suren Baghdasaryan <surenb@...gle.com>, Michal Hocko <mhocko@...e.com>, 
	Johannes Weiner <hannes@...xchg.org>, Zi Yan <ziy@...dia.com>, 
	Axel Rasmussen <axelrasmussen@...gle.com>, Yuanchu Xie <yuanchu@...gle.com>, 
	Roman Gushchin <roman.gushchin@...ux.dev>, <peterz@...radead.org>, 
	<dave.hansen@...ux.intel.com>, <mingo@...hat.com>, <tglx@...utronix.de>, 
	<akpm@...ux-foundation.org>, <david@...hat.com>, <derkling@...gle.com>, 
	<junaids@...gle.com>, <linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>, 
	<reijiw@...gle.com>, <rientjes@...gle.com>, <rppt@...nel.org>, 
	<vbabka@...e.cz>, <x86@...nel.org>, Yosry Ahmed <yosry.ahmed@...ux.dev>
Subject: Re: [PATCH 05/21] x86/mm/pat: mirror direct map changes to ASI

On Tue Jan 20, 2026 at 4:37 PM UTC, Borislav Petkov wrote:
> On Thu, Oct 02, 2025 at 05:08:59PM +0000, Brendan Jackman wrote:
>> OK, then it probably just sounds wrong to me because I'm steeped in the
>> current jargon. For v2 I'll try just dropping "[un]restricted".
>
> So AFAIU, we have two address spaces - the full one - which has *everything*
> mapped in and the limited one, with things removed from it. Right?
>
> So calling the unrestricted "the full address space" makes sense to me. I.e.,
> it has *everything* in it.
>
> And then there's the subset of the full address space which has holes in it.
> Looking at Merriam Webster, it suggests those antonyms to "complete":
>
> partial, incomplete, reduced, abbreviated, diminished.
>
> Yahaa, they all make sense.
>
> "partial address space" sounds good to me. "Reduced" even better. So having
> the full and the reduced address space would make the nomenclature very easy,
> IMO. 
>
> Thoughts?

Full/partial sounds like good naming for the address spaces, but that
doesn't help with the issue that we have two related concepts that we
need jargon for:

1. Address spaces (current patch's terminology: restricted/unrestricted)

2. The property of some memory being mapped or unmapped in the
   "restricted"/"partial"/"sensitive" address space (current patch's
   terminology: sensitive/nonsensitive).

IIUC Dave's complaint wasn't that the word choices don't work for their
respective concepts. His issue was that we have separte jargon for 1 and
2 even though they are closely entangled concepts. Since I'm now
convinced that "sensitive/nonsensitive" makes sense for both, I think we
should stick to that.