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Date: Thu, 8 Feb 2018 20:52:40 +0000
From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: tedheadster <tedheadster@gmail.com>
Cc: whiteheadm@acm.org, David Laight <David.Laight@aculab.com>,
        Arnd
 Bergmann <arnd@arndb.de>,
        Ondrej Zary <linux@rainbow-software.org>,
        David
 Woodhouse <dwmw2@infradead.org>,
        Guenter Roeck <linux@roeck-us.net>,
        Greg
 Kroah-Hartman <gregkh@linuxfoundation.org>,
        Hugh Dickins
 <hughd@google.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Jiri Kosina
 <jikos@kernel.org>, Borislav Petkov <bp@alien8.de>,
        Kees Cook
 <keescook@chromium.org>, Jamie Iles <jamie@jamieiles.com>,
        Eduardo Valentin
 <eduval@amazon.com>,
        Laura Abbott <labbott@redhat.com>, Rik van Riel
 <riel@surriel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linux Kernel
 Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [BUG] x86 : i486 reporting to be vulnerable to
 Meltdown/Spectre_V1/Spectre_V2
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> > Also worth nothing that the difference between the cpu and memory
> > speeds is much lower - so far fewer instructions could be speculatively
> > executed while waiting a cache miss.

But they also have more instructions that take a lot of clocks and are
easier to stall - eg by doing things like opening and mmapping
a framebuffer and then doing a floating point double store to it
misaligned.

Meltdown we can at least reasonably test but spectre is hard.

Alan