Subject: Re: [PATCH 1/3] x86: record relocation offset
From: James Bottomley <James.Bottomley@suse.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>,
       Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>,
       Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
       Peter Zijlstra <peterz@infradead.org>,
       Frederic Weisbecker <fweisbec@gmail.com>,
       Paul Mackerras <paulus@samba.org>, "Frank Ch. Eigler" <fche@redhat.com>,
       linux-kernel@vger.kernel.org
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References: <vxv6sfpjggfx6v68yv1eecrx.1262215615671@email.android.com>
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Date: Wed, 30 Dec 2009 17:41:46 -0600
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On Wed, 2009-12-30 at 15:26 -0800, H. Peter Anvin wrote:
> Modules are a completely separate thing - they are linked (not even
> just relocated) at insertion time, so they need to be tracked
> separately.

The reasons I gave was why _text relocation didn't work properly for
systemtap.  The first paragraph was just giving a precis of history
explaining to Arnaldo why he remembered there was a problem with _text
based relocations.

> The statement that a _text-based relocation is insufficient is false.
> The entire x86-32 monolithic kernel is relocated as a unit.  The
> x86-64 kernel, too, is relocated as a unit, but using the page tables,
> which means it always runs at the compile-time-selected virtual
> address.

Confused now ... you just repeated what I said in the second paragraph,
but made it sound like you are disagreeing?

James


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