Date: Sun, 7 Jan 2018 14:01:38 +0000
From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: Kiernan Hager <kah.listaddress@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Avoid speculative indirect calls in kernel
Message-ID: <20180107140138.08a7e8e3@alans-desktop>
In-Reply-To: <CAL9bgJ942ekzyCrposr-xPeTNyh==d2JMO5LvvwuSOKQ38BgBw@mail.gmail.com>
References: <20180103230934.15788-1-andi@firstfloor.org>
        <CA+55aFzCocoK+4kxAUEhaxxba4RTv3ewBmhiZ8Osc9iDkBtCEQ@mail.gmail.com>
        <e64025e6-9c4f-703d-cb69-29eeb9cc16bd@redhat.com>
        <20180104015920.1ad7b9d3@alans-desktop>
        <e3a0fa73-1328-aa42-13ea-c670c8d4ac87@redhat.com>
        <1515054014.12987.75.camel@amazon.co.uk>
        <403e65be-cfd1-fd08-0401-2e26470b63d4@redhat.com>
        <4dde456c-fd15-e768-8876-5844c8b7c455@redhat.com>
        <alpine.DEB.2.20.1801050153290.2127@nanos>
        <CAL9bgJ8XNJgCtxR6+M+Vm9eDBVZ4Dyi_-Lt-Q1ei9N=TE2c6cg@mail.gmail.com>
        <CAL9bgJ942ekzyCrposr-xPeTNyh==d2JMO5LvvwuSOKQ38BgBw@mail.gmail.com>
Organization: Intel Corporation
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org

> I disagree. When there are patches that slow execution down up to 30%,
> I want to be able to mark a binary as "trusted" so that I can run it

It's not a binary that is trusted - it's a binary in a given use case.
You could easily have the same binary being run in two situations on the
same box at the same time and run just one of them 'trusted'.