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Message-ID: <7f392b4e-9970-42d4-8204-2aa967a5375d@sirena.org.uk>
Date: Fri, 1 Nov 2024 22:39:15 +0000
From: Mark Brown <broonie@...nel.org>
To: "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
Cc: "debug@...osinc.com" <debug@...osinc.com>,
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Subject: Re: [PATCH RFC/RFT v2 2/2] kernel: converge common shadow stack flow
agnostic to arch
On Fri, Nov 01, 2024 at 09:50:27PM +0000, Edgecombe, Rick P wrote:
> On Wed, 2024-10-16 at 14:57 -0700, Deepak Gupta wrote:
> > - * The maximum distance INCSSP can move the SSP is 2040 bytes, before
> > - * it would read the memory. Therefore a single page gap will be enough
> > - * to prevent any operation from shifting the SSP to an adjacent stack,
> > - * since it would have to land in the gap at least once, causing a
> > - * fault.
> I want to take a deeper look at this series once I can apply and test it, but
> can we maybe make this comment more generic and keep it? I think it is similar
> reasoning for arm (?), is there anything situation like this for risc-v? Or
> rather, why does risc-v have the guard gaps?
Yes, for arm64 you can only move the pointer in single frames so a
single page is enough.
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