From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x2251FRXadew3RiksCppPnzk8jsuVVlf4uYAETXJx2NcZ2WPr6TcYJQM/KqhCdYvdm47P4c3P ARC-Seal: i=1; a=rsa-sha256; t=1518555887; cv=none; d=google.com; s=arc-20160816; b=K0uDyt0rHMAKMipXuB6DScK95TSZm7N24McbWUWwiCaaXFzzqyJMMYV1dz4w5JqF71 5gvqRkfx08hRP+pRdaV0iGykM4WPfOviTfuYInw+GyP7OWt66WBlGxi7nC1bXqETgTv3 yVe86fyNWDq7ezBLXeP7UjypsAK9QvnNTBj9ACKHIUV0OMm0eiR3OjkbOhrkTms1O+GZ vU4a4qfk29a/0Q3CoLIer5uaB7c7RYDAq+MkvzvcK63g0iajmQ8NwL9dx3AxVkvxCEw7 0i7lg4LVpKGu46XbEsHnJ77ZdqjA6z9WbWMuZzntDvqcv/QpUpDPi/4ZEHNEJEF1rmQq Mwtw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:arc-authentication-results; bh=DVOR2TbPhXMke7RIvyEthGIjHJsqiz9p3KKRGoERABo=; b=hDYazZjyPb5wsaI34ZBC8XTyV7mNTHv1nmNtFBCyPqwWOSehgXikV+SRgWx7n1BKtW TJTplaVLFzDmYLoQjGFa9bC+mjkd7z8DS86D2MytrSQKW1JHih+fr2ZU6Je28SM9V9KY 2Ii3e37NihsBDLkR7l5KNWxPgOzfR5W7EAop2wStDLL2qbY83NB9IRLISBE0+YgnfiZM tULdOuF2ioGzRpX6onsO5c2AH1aMDlKWcgftPJKQ8oRlU0WJJoXLevVEF7O8mS9CrSAh TVaK9RgH2VgEb1dlrVeUcH4sgOqyzILwM5QVBWTdrkDKd8p4jYTNq3FNCa01oQXjIRGY kgbA== ARC-Authentication-Results: i=1; mx.google.com; spf=neutral (google.com: 195.113.26.193 is neither permitted nor denied by best guess record for domain of pavel@ucw.cz) smtp.mailfrom=pavel@ucw.cz Authentication-Results: mx.google.com; spf=neutral (google.com: 195.113.26.193 is neither permitted nor denied by best guess record for domain of pavel@ucw.cz) smtp.mailfrom=pavel@ucw.cz Date: Tue, 13 Feb 2018 22:04:48 +0100 From: Pavel Machek To: Alan Cox Cc: tedheadster , whiteheadm@acm.org, David Laight , Arnd Bergmann , Ondrej Zary , David Woodhouse , Guenter Roeck , Greg Kroah-Hartman , Hugh Dickins , Dave Hansen , Jiri Kosina , Borislav Petkov , Kees Cook , Jamie Iles , Eduardo Valentin , Laura Abbott , Rik van Riel , Thomas Gleixner , Linux Kernel Mailing List Subject: Re: [BUG] x86 : i486 reporting to be vulnerable to Meltdown/Spectre_V1/Spectre_V2 Message-ID: <20180213210448.GB6569@amd> References: <1517950494.3677.30.camel@infradead.org> <201802070918.18978.linux@rainbow-software.org> <20180208134908.4b516794@alans-desktop> <63ca28c5acb64de5ba33a81b6da5c507@AcuMS.aculab.com> <20180208205240.0c53631f@alans-desktop> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="zx4FCpZtqtKETZ7O" Content-Disposition: inline In-Reply-To: <20180208205240.0c53631f@alans-desktop> User-Agent: Mutt/1.5.23 (2014-03-12) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1591354140743903681?= X-GMAIL-MSGID: =?utf-8?q?1592321258578962845?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: --zx4FCpZtqtKETZ7O Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu 2018-02-08 20:52:40, Alan Cox wrote: > > > Also worth nothing that the difference between the cpu and memory > > > speeds is much lower - so far fewer instructions could be speculative= ly > > > executed while waiting a cache miss. >=20 > 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. >=20 > Meltdown we can at least reasonably test but spectre is hard. Do you have pointer for simple meltdown test? I've got https://github.com/IAIK/meltdown.git but could not get it to work even on machines that should be vulnerable. Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --zx4FCpZtqtKETZ7O Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlqDUvAACgkQMOfwapXb+vJOxwCcD6LBvq0LQ4K+5eB5YrMtAcB0 fFgAnjHZFKzAx94oBpJSDeDyy6waCEjA =mScl -----END PGP SIGNATURE----- --zx4FCpZtqtKETZ7O--