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Date: Mon, 16 Mar 2015 16:03:45 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Eugene Shatokhin <eugene.shatokhin@rosalab.ru>,
        Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH] kprobes/x86: Return correct length in
 __copy_instruction()
Message-ID: <20150316150345.GA18641@gmail.com>
References: <1425899954-24380-1-git-send-email-eugene.shatokhin@rosalab.ru>
 <54FE5E14.8090303@hitachi.com>
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* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> (2015/03/09 20:19), Eugene Shatokhin wrote:
> > On x86-64, __copy_instruction() always returns 0 (error) if the
> > instruction uses %rip-relative addressing. This is because
> > kernel_insn_init() is called the second time for 'insn' instance
> > in such cases and sets all its fields to 0.
> > 
> > Because of this, trying to place a Kprobe on such instruction will
> > fail, register_kprobe() will return -EINVAL.
> 
> Oops, good catch!
> 
> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Mind resending it with your SOB, as I wasn't Cc:-ed on the original 
submission?

Thanks,

	Ingo