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Date: Wed, 30 Nov 2011 19:57:51 +0100
From: Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH v7 3.2-rc2 8/30] x86: analyze instruction and determine
	fixups.
Message-ID: <20111130185751.GA8160@redhat.com>
References: <20111118110631.10512.73274.sendpatchset@srdronam.in.ibm.com> <20111118110808.10512.72719.sendpatchset@srdronam.in.ibm.com>
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To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>, Linus Torvalds <torvalds@linux-foundation.org>, Andrew Morton <akpm@linux-foundation.org>, LKML <linux-kernel@vger.kernel.org>, Linux-mm <linux-mm@kvack.org>, Ingo Molnar <mingo@elte.hu>, Andi Kleen <andi@firstfloor.org>, Christoph Hellwig <hch@infradead.org>, Steven Rostedt <rostedt@goodmis.org>, Roland McGrath <roland@hack.frob.com>, Thomas Gleixner <tglx@linutronix.de>, Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>, Arnaldo Carvalho de Melo <acme@infradead.org>, Anton Arapov <anton@redhat.com>, Ananth N Mavinakayanahalli <ananth@in.ibm.com>, Jim Keniston <jkenisto@linux.vnet.ibm.com>, Stephen Wilson <wilsons@start.ca>

On 11/18, Srikar Dronamraju wrote:
>
> +static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe,
> +							struct insn *insn)
> +{
> [...snip...]
> +	if (insn->immediate.nbytes) {
> +		cursor++;
> +		memmove(cursor, cursor + insn->displacement.nbytes,
> +						insn->immediate.nbytes);
> +	}
> +	return;
> +}

Of course I don not understand this code. But it seems that it can
rewrite uprobe->insn ?

If yes, don't we need to save the original insn for unregister_uprobe?

Oleg.

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