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From: William Lee Irwin III <wli@holomorphy.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: __init poisoning for i386, too
Date: Fri, 8 Oct 2004 04:08:45 -0700	[thread overview]
Message-ID: <20041008110845.GC9106@holomorphy.com> (raw)
In-Reply-To: <ck4b39$fmp$1@terminus.zytor.com>

At some point in the past, I wrote:
>> Any chance we could:
>> (a) set the stuff to 0x0f0b so illegal instructions come of it; jumps are
>> 	most often aligned to something > 16 bits anyway
>> (b) poison __initdata, memsetting to some bit pattern oopsable to dereference

On Thu, Oct 07, 2004 at 09:05:45PM +0000, H. Peter Anvin wrote:
> What's wrong with using 0xCC (breakpoint instruction)?
> If you want an illegal instruction, 0xFF 0xFF is an illegal
> instruction, so filling memory with 0xFF will do what you want.

That sounds better than what I suggested.


-- wli

  reply	other threads:[~2004-10-08 11:09 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-06 22:18 __init poisoning for i386, too Pavel Machek
2004-10-06 22:29 ` Andrew Morton
2004-10-07  8:22   ` Geert Uytterhoeven
2004-10-06 23:56 ` Nigel Cunningham
2004-10-07  8:02   ` Pavel Machek
2004-10-07  6:16 ` William Lee Irwin III
2004-10-07 21:05   ` H. Peter Anvin
2004-10-08 11:08     ` William Lee Irwin III [this message]
2004-10-08 11:23       ` Ryan Cumming
     [not found] <20041006221854.GA1622@elf.ucw.cz.suse.lists.linux.kernel>
     [not found] ` <20041007061610.GU9106@holomorphy.com.suse.lists.linux.kernel>
2004-10-07 11:28   ` Andi Kleen

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