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From: "H. Peter Anvin" <hpa@zytor.com>
To: Joe Damato <ice799@gmail.com>
Cc: linux-x86_64@vger.kernel.org, w@1wt.eu, mingo@elte.hu,
	jeremy@goop.org, linux-newbie@vger.kernel.org,
	kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] x86: Add getter/setter static inlines for x86 descriptors
Date: Sun, 29 Mar 2009 14:28:00 -0700	[thread overview]
Message-ID: <49CFE7E0.80500@zytor.com> (raw)
In-Reply-To: <76c37743d20e5737eadc747cbdddbc2beb11f074.1238361501.git.ice799@gmail.com>

Joe Damato wrote:
> Static inline getters/setters have been provided to encourage consumers not to touch the internals of 32bit x86 descriptors directly.
> 
> Signed-off-by: Joe Damato <ice799@gmail.com>

Okay, what is the motivation for this?

This is a serious question.  The x86 descriptors are so complex that
it's not clear to me that this restriction makes the code any more
clear.  Especially not with things like:

-		cpu->arch.gdt[i].b |= 0x00000100;
+		desc_set_hi(tmp,  desc_get_hi(tmp) | 0x00000100);

This isn't an improvement.  If you're doing to so something like this,
you need to actually implement the *intent* here.

	-hpa

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


  reply	other threads:[~2009-03-29 21:32 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-29 21:21 [PATCH 0/2] x86: Remove direct access to internal x86 descriptor fields Joe Damato
2009-03-29 21:21 ` [PATCH 1/2] x86: Add getter/setter static inlines for x86 descriptors Joe Damato
2009-03-29 21:28   ` H. Peter Anvin [this message]
2009-03-29 21:50     ` Joe Damato
2009-03-29 22:10       ` H. Peter Anvin
2009-03-29 21:21 ` [PATCH 2/2] x86: Replace direct access to descriptor fields with getter/setters Joe Damato

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