linux-kernel - Re: Did we really need to clear the IF flag at prepare

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Date:	Tue, 12 Jan 2010 08:06:00 -0800
From:	Arjan van de Ven <arjan@...radead.org>
To:	Dongdong Deng <libfetion@...il.com>
Cc:	linux-kernel@...r.kernel.org, ananth@...ibm.com,
	anil.s.keshavamurthy@...el.com, davem@...emloft.net,
	mhiramat@...hat.com, jkenisto@...ibm.com
Subject: Re: Did we really need to clear the IF flag at prepare_singlestep()
 of  x86 kprobes?

On Tue, 12 Jan 2010 19:09:35 +0800
Dongdong Deng <libfetion@...il.com> wrote:

> Hi Kprobe experts,
> 
> I have a doubt about the handling "X86_EFLAGS_IF" at
> prepare_singlestep(), Could you give me some suggestions?


iirc it was a security thing; we used to have some exploits
due to the linux-abi entry points which caused a mess, and this
was put there as defensive programming.

I could totally misremember this as well of course.


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
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