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From: Arjan van de Ven <arjan@infradead.org>
To: Dongdong Deng <libfetion@gmail.com>
Cc: linux-kernel@vger.kernel.org, ananth@in.ibm.com,
	anil.s.keshavamurthy@intel.com, davem@davemloft.net,
	mhiramat@redhat.com, jkenisto@us.ibm.com
Subject: Re: Did we really need to clear the IF flag at prepare_singlestep() of  x86 kprobes?
Date: Tue, 12 Jan 2010 08:06:00 -0800	[thread overview]
Message-ID: <20100112080600.392c14cd@infradead.org> (raw)
In-Reply-To: <ce2c83091001120309q19d58b45kc27610fc31ce01dc@mail.gmail.com>

On Tue, 12 Jan 2010 19:09:35 +0800
Dongdong Deng <libfetion@gmail.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, 
visit http://www.lesswatts.org

  reply	other threads:[~2010-01-12 16:06 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-12 11:09 Did we really need to clear the IF flag at prepare_singlestep() of x86 kprobes? Dongdong Deng
2010-01-12 16:06 ` Arjan van de Ven [this message]
2010-01-13  5:25   ` Dongdong Deng
2010-01-13  6:18 ` Masami Hiramatsu
2010-01-14  6:45   ` Dongdong Deng
2010-01-14 20:06     ` Masami Hiramatsu

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