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From: "Manfred Spraul" <manfred@colorfullife.com>
To: "Daniel Jacobowitz" <dan@debian.org>
Cc: <linux-kernel@vger.kernel.org>, "Andrew Morton" <akpm@zip.com.au>
Subject: Re: [PATCH?] Crash in 2.4.17/ptrace
Date: Mon, 28 Jan 2002 22:33:35 +0100
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> >
> > Not with this patch, I'm afraid.  For your testing purposes you
> > could just remove the VALID_PAGE() test in
mm/memory.c:get_page_map(),
> > and then gdb should be able to get at the framebuffer.
>
> I'm sure there's a good reason to not do that in general.  Mind
> enlightening me?

Please don't do it at all.
The test is there to ensure that there is a 'struct page' for address
found in the pages tables.
For framebuffers addresses, there is no page structure, and then the
page reference count updates read/write to random memory.

--
    Manfred

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