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Date:   Wed, 19 Oct 2022 13:38:17 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Josh Poimboeuf <jpoimboe@kernel.org>
Cc:     Kees Cook <keescook@chromium.org>, x86@kernel.org,
        Sami Tolvanen <samitolvanen@google.com>,
        Joao Moreira <joao@overdrivepizza.com>,
        linux-kernel@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH] x86/ibt: Implement FineIBT
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On Tue, Oct 18, 2022 at 04:31:48PM -0700, Josh Poimboeuf wrote:

> Is there a reason not to default to FineIBT if the hardware supports it?

Not really; and that's the default implemented here. Kees seems to think
the kCFI thing is a little more resillient against attacks where the
attacker can write code -- but IMO that's a bit of a lost cause.

Being able to run kCFI on IBT hardware is useful for
development/debugging purposes though.