linux-kernel - Re: [PATCH 3/7] mtrr: Remove use

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20091209083437.GA27838@rere.qmqm.pl>
Date:	Wed, 9 Dec 2009 09:34:37 +0100
From:	Michał Mirosław <mirq-linux@...e.qmqm.pl>
To:	Yinghai Lu <yhlu.kernel@...il.com>
Cc:	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org
Subject: Re: [PATCH 3/7] mtrr: Remove use_intel()

On Wed, Dec 09, 2009 at 12:10:50AM -0800, Yinghai Lu wrote:
> 2009/12/8 Michał Mirosław <mirq-linux@...e.qmqm.pl>:
> > Remove use_intel() and use is_cpu(INTEL) instead.
> >
> > .use_intel_if is duplicating information already found in .vendor, as
> > the only combinations used are:
> >    generic: use_intel_if == 1, vendor == INTEL
> >    amd/cyrix/centaur: use_intel_if == 0, vendor != INTEL
> >
[...]
> can you check it with amd64 cpu?

Unfortunately I don't have any AMD machines right now.

Anyway, just to clarify why the change is a functional no-op: use_intel()
and is_cpu(X) don't check the detected CPU vendor ID but look into mtrr_ops
struct. For 64BIT build this means that use_intel() / is_cpu(INTEL) == true
when mtrr_if != NULL, and all other is_cpu() == false because no other
implementation could be choosen (amd/cyrix/centaur special cpu features are
possible only in 32BIT).

Best Regards,
Michał Mirosław
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/