linux-kernel - Re: [PATCH v7 21/41] mm: Add guard pages around a shadow stack.

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Message-ID: <20230307103251.GAZAcS0zpon573Ox3N@fat_crate.local>
Date:   Tue, 7 Mar 2023 11:32:51 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
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Subject: Re: [PATCH v7 21/41] mm: Add guard pages around a shadow stack.

On Tue, Mar 07, 2023 at 01:29:50AM +0000, Edgecombe, Rick P wrote:
> On Mon, 2023-03-06 at 09:08 +0100, Borislav Petkov wrote:
> > Just typos:
> 
> All seem reasonable to me. Thanks. 
> 
> For using the log verbiage for the comment, it is quite big. Does
> something like this seem reasonable?

Yeah, it does. I wouldn't want to lose that explanation in a commit
message.

However, this special aspect pertains to the shstk implementation in x86
but the code is generic mm and such arch-specific comments are kinda
unfitting there.

I wonder if it would be better if you could stick that explanation
somewhere in arch/x86/ and only refer to it in a short comment above
VM_SHADOW_STACK check in stack_guard_start_gap()...

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette