linux-kernel - Re: [PATCH 3/3] x86, AMD: Disable wrongly set X86_FEATURE_LAHF

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: <4A9AE5B1.80305@zytor.com>
Date:	Sun, 30 Aug 2009 13:48:49 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Borislav Petkov <petkovbb@...glemail.com>, mingo@...hat.com,
	linux-kernel@...r.kernel.org, kjwinchester@...il.com,
	tglx@...utronix.de, borislav.petkov@....com,
	linux-tip-commits@...r.kernel.org
Subject: Re: [PATCH 3/3] x86, AMD: Disable wrongly set X86_FEATURE_LAHF_LM
 CPUID bit

On 08/30/2009 01:29 PM, Borislav Petkov wrote:
> 
> Ok, what do we want actually? We have rdmsr_safe and rdmsrl_safe where
> the last one engineers the 2 u32s into a u64. My gut feeling would opt
> for the 2 32bit values instead of one 64bit since they're naturally
> returned into %eax:%edx. And in the most cases we need only one of the
> values. However, the MSRs themselves are 64bit... Hmmm...
> 

The 2x32 bit interface is the legacy interface.  It turned out to be a
bad idea, but it's hard to clean up all the users.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
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/