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Date: Sun, 9 Oct 2011 15:31:40 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@elte.hu>,
        Steven Rostedt <rostedt@goodmis.org>, Linux-mm <linux-mm@kvack.org>,
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        Thomas Gleixner <tglx@linutronix.de>,
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        Andrew Morton <akpm@linux-foundation.org>,
        Jim Keniston <jkenisto@linux.vnet.ibm.com>,
        Roland McGrath <roland@hack.frob.com>,
        Andi Kleen <andi@firstfloor.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 3.1.0-rc4-tip 12/26]   Uprobes: Handle breakpoint
	and Singlestep
Message-ID: <20111009133139.GA28332@redhat.com>
References: <20110920115938.25326.93059.sendpatchset@srdronam.in.ibm.com> <20110920120221.25326.74714.sendpatchset@srdronam.in.ibm.com> <20111007182834.GA1655@redhat.com>
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On 10/07, Oleg Nesterov wrote:
>
> What if the forking task (current) is in UTASK_BP_HIT state?
> ...
>
> And what if we step into a syscall insn?
> ...

And I guess there would be a lot more problems here. But, looking
at is_prefix_bad() I see the nice comment:

	* opcodes we'll probably never support:
	* 0f - lar, lsl, syscall, clts, sysret, sysenter, sysexit, invd, wbinvd, ud2

This answers my questions.

> Please simply ignore my email if you think everything is fine.

Yep.

Oleg.