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From: David Hildenbrand <david@redhat.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
	Ryan Roberts <ryan.roberts@arm.com>,
	Matthew Wilcox <willy@infradead.org>
Subject: Re: The future of PageAnonExclusive
Date: Wed, 11 Dec 2024 14:48:28 +0100	[thread overview]
Message-ID: <b153a96d-c777-49f7-8aa5-018fb41fb79f@redhat.com> (raw)
In-Reply-To: <oelikmopexm66p7pthwrt5qw6w4ro3hduc6thefvxdhcx2l27v@bxln22rb55hx>

On 11.12.24 14:42, Kirill A. Shutemov wrote:
> On Wed, Dec 11, 2024 at 12:56:11PM +0100, David Hildenbrand wrote:
>>> (C) Encode it in the PTE.
>>>
>>>        pte_write() -> PAE
>>>
>>>        !pte_write() && pte_dirty() -> PAE
>>>
>>>        !pte_write && !pte_dirty() -> !PAE
> 
> You are late to the party. On x86, !pte_write() && pte_dirty() is shadow
> stack.
> 

Hah, no, it works! :)

On x86 we use this fancy savedirty bit to handle that internally, such 
that pte_write/pte_dirty keep working as expected on shadow stacks.

-- 
Cheers,

David / dhildenb



  reply	other threads:[~2024-12-11 13:48 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-11 11:55 David Hildenbrand
2024-12-11 11:56 ` David Hildenbrand
2024-12-11 13:42   ` Kirill A. Shutemov
2024-12-11 13:48     ` David Hildenbrand [this message]
2024-12-11 14:25   ` Ryan Roberts
2024-12-11 14:49     ` David Hildenbrand
2024-12-11 15:45       ` Matthew Wilcox
2024-12-11 15:50         ` David Hildenbrand
2024-12-11 16:11           ` Matthew Wilcox
2024-12-11 16:15             ` David Hildenbrand

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