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From: "H. Peter Anvin" <hpa-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
To: Neil Horman <nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>,
	dev-VfR2kkLFssw@public.gmane.org
Subject: Re: [PATCH v5] eal_common_cpuflags: Fix %rbx corruption, and simplify the code
Date: Tue, 25 Mar 2014 13:51:04 -0700	[thread overview]
Message-ID: <5331EC38.2070901@linux.intel.com> (raw)
In-Reply-To: <1395777179-4345-1-git-send-email-nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>

On 03/25/2014 12:52 PM, Neil Horman wrote:
> Neil Horman reported that on x86-64 the upper half of %rbx would get
> clobbered when the code was compiled PIC or PIE, because the
> i386-specific code to preserve %ebx was incorrectly compiled.
> 
> However, the code is really way more complex than it needs to be.  For
> one thing, the CPUID instruction only needs %eax (leaf) and %ecx
> (subleaf) as parameters, and since we are testing for bits, we might
> as well list the bits explicitly.  Furthermore, we can use an array
> rather than doing a switch statement inside a structure.
> 
> Reported-by: Neil Horman <nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>
> Signed-off-by: H. Peter Anvin <hpa-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Signed-off-by: Neil Horman <nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>
> 

Looks good to me.

Reviewed-by: H. Peter Anvin <hpa-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

	-hpa

  parent reply	other threads:[~2014-03-25 20:51 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1395330830-1310-1-git-send-email-hpa@linux.intel.com>
     [not found] ` <1395330830-1310-1-git-send-email-hpa-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2014-03-20 16:39   ` [RFC UNTESTED PATCH] eal_common_cpuflags: Fix %rbx corruption, and simplify the code Neil Horman
     [not found]     ` <20140320163921.GC7721-B26myB8xz7F8NnZeBjwnZQMhkBWG/bsMQH7oEaQurus@public.gmane.org>
2014-03-20 17:02       ` Thomas Monjalon
2014-03-20 18:04       ` Neil Horman
     [not found]         ` <20140320180443.GE7721-B26myB8xz7F8NnZeBjwnZQMhkBWG/bsMQH7oEaQurus@public.gmane.org>
2014-03-20 18:59           ` Neil Horman
2014-03-21 14:49       ` [PATCH v2] " Neil Horman
     [not found]         ` <1395413340-27392-1-git-send-email-nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>
2014-03-21 15:03           ` H. Peter Anvin
     [not found]             ` <532C54C6.2060202-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2014-03-21 17:48               ` Neil Horman
     [not found]                 ` <20140321174839.GB21998-B26myB8xz7F8NnZeBjwnZQMhkBWG/bsMQH7oEaQurus@public.gmane.org>
2014-03-24 11:18                   ` Thomas Monjalon
2014-03-24 17:44       ` [PATCH v3] " Neil Horman
     [not found]         ` <1395683088-19687-1-git-send-email-nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>
2014-03-24 18:09           ` H. Peter Anvin
     [not found]             ` <533074F0.3060204-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2014-03-24 19:52               ` Neil Horman
     [not found]                 ` <20140324195206.GG19368-B26myB8xz7F8NnZeBjwnZQMhkBWG/bsMQH7oEaQurus@public.gmane.org>
2014-03-24 20:47                   ` H. Peter Anvin
     [not found]                     ` <533099FB.5030702-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2014-03-25 10:41                       ` Neil Horman
2014-03-25 17:03       ` [PATCH v4] " Neil Horman
     [not found]         ` <1395767000-28709-1-git-send-email-nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>
2014-03-25 17:06           ` Chris Wright
2014-03-25 17:37           ` H. Peter Anvin
2014-03-25 19:52       ` [PATCH v5] " Neil Horman
     [not found]         ` <1395777179-4345-1-git-send-email-nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>
2014-03-25 20:51           ` H. Peter Anvin [this message]
     [not found]             ` <5331EC38.2070901-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2014-04-02 11:16               ` Neil Horman
     [not found]                 ` <20140402111643.GB6974-0o1r3XBGOEbbgkc5XkKeNuvMHUBZFtU3YPYVAmT7z5s@public.gmane.org>
2014-04-02 11:53                   ` Thomas Monjalon
2014-04-02 12:42               ` Thomas Monjalon
2014-04-15 14:09 De Lara Guarch, Pablo
     [not found] ` <E115CCD9D858EF4F90C690B0DCB4D8970829CEB8-kPTMFJFq+rELt2AQoY/u9bfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2014-04-15 14:56   ` Neil Horman
     [not found]     ` <20140415145612.GE3557-B26myB8xz7F8NnZeBjwnZQMhkBWG/bsMQH7oEaQurus@public.gmane.org>
2014-04-16  8:36       ` De Lara Guarch, Pablo
  -- strict thread matches above, loose matches on Subject: below --
2014-04-16  8:58 De Lara Guarch, Pablo
     [not found] ` <E115CCD9D858EF4F90C690B0DCB4D8970829D14A-kPTMFJFq+rELt2AQoY/u9bfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2014-04-16  9:06   ` Thomas Monjalon
2014-04-16 10:49   ` Neil Horman
     [not found]     ` <20140416104955.GA26829-B26myB8xz7F8NnZeBjwnZQMhkBWG/bsMQH7oEaQurus@public.gmane.org>
2014-04-16 11:09       ` De Lara Guarch, Pablo
     [not found]         ` <E115CCD9D858EF4F90C690B0DCB4D8970829D24B-kPTMFJFq+rELt2AQoY/u9bfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2014-04-16 12:53           ` Neil Horman

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