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Date:   Tue, 18 Oct 2022 10:20:12 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Joao Moreira <joao@overdrivepizza.com>
Cc:     David Laight <David.Laight@aculab.com>,
        'Peter Zijlstra' <peterz@infradead.org>, x86@kernel.org,
        Sami Tolvanen <samitolvanen@google.com>,
        linux-kernel@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH] x86/ibt: Implement FineIBT
Message-ID: <202210181013.923F8809@keescook>
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 <3edb387ea335085dcb6dd49f1d9c9ce6@overdrivepizza.com>
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On Tue, Oct 18, 2022 at 08:58:24AM -0700, Joao Moreira wrote:
> > Does the hash value for kCFI only depend on the function type?
> > Or is there something like a attribute that can also be included?
> 
> Hi David -- does this sound like what you are asking about?
> 
> https://github.com/ClangBuiltLinux/linux/issues/1736
> 
> If yes, then it is something in our todo list :) I think Sami is handling
> it.

I was hoping someone with prior experience with Call Graph Detaching to
solve Transitive Clustering Relaxation[1] could assist? ;)

-Kees

[1] https://www.blackhat.com/docs/asia-17/materials/asia-17-Moreira-Drop-The-Rop-Fine-Grained-Control-Flow-Integrity-For-The-Linux-Kernel.pdf

-- 
Kees Cook