Re: [Fwd: Re: [RFA 3/5] Prec: x86 segment register support: target]

[Hui Zhu <teawater at gmail dot com>]

On Wed, May 5, 2010 at 10:46, Hui Zhu <teawater@gmail.com> wrote:
> On Fri, Apr 30, 2010 at 19:07, Hui Zhu <teawater@gmail.com> wrote:
>> On Fri, Apr 30, 2010 at 17:33, Mark Kettenis <mark.kettenis@xs4all.nl> wrote:
>>>> From: Hui Zhu <teawater@gmail.com>
>>>> Date: Fri, 30 Apr 2010 14:29:09 +0800
>>>>
>>>> On Thu, Mar 25, 2010 at 10:14, Hui Zhu <teawater@gmail.com> wrote:
>>>> > On Thu, Mar 25, 2010 at 02:44, Doug Evans <dje@google.com> wrote:
>>>> >>
>>>> >> On Mon, Mar 22, 2010 at 7:59 PM, Hui Zhu <teawater@gmail.com> wrote:
>>>> >> > On Tue, Mar 23, 2010 at 02:47, Doug Evans <dje@google.com> wrote:
>>>> >> >> On Mon, Mar 22, 2010 at 11:26 AM, Michael Snyder <msnyder@vmware.com> wrote:
>>>> >> >>> I'd just like to point out that while all this sounds great,
>>>> >> >>> it shouldn't be a prerequisite to the original task of just
>>>> >> >>> getting prec to record the segments and offsets correctly.
>>>> >> >>>
>>>> >> >>> Maybe we should split these two tasks, so that Teawater can
>>>> >> >>> go ahead and accomplish his.
>>>> >> >>
>>>> >> >> To the extent that they can be split, IWBN alright.
>>>> >> >>
>>>> >> >> I wonder if the interface is sufficient though (setting aside where to
>>>> >> >> put it and how it will look).
>>>> >> >> Any particular o/s might not provide sufficient hooks of course.
>>>> >> >> linux's modify_ldt, AIUI, let's one change more than just foo_base.
>>>> >> >> NativeClient http://code.google.com/p/nativeclient/ uses it, for example.
>>>> >> >>
>>>> >> >
>>>> >> > Thanks Doug.
>>>> >> >
>>>> >> > I suggest we support segment base step by step.
>>>> >> > When the OS that support it will show the xxx_base to user, the
>>>> >> > unsupport OS will show nothing.
>>>> >> >
>>>> >> > What do you think about it?
>>>> >>
>>>> >> Is supporting segment base sufficient?
>>>> >> Or do you also need to support, e.g., segment limit and flags too?
>>>> >> There may be more, but they're the two that come to mind.
>>>> >> [That's what I was referring to regarding whether the interface was sufficient.]
>>>> >
>>>> > Prec just need the base to get the insn memory operate address. ?Do
>>>> > you think we need other message of segment?
>>>> >
>>>> > If need, do we need divide all message like eflags?
>>>> >
>>>> > Thanks,
>>>> > Hui
>>>> >
>>>>
>>>> Hi all,
>>>>
>>>> X86 looks stab now. ?Shall we wake up this patch?
>>>
>>> Thanks for the reminder.
>>>
>>> Let me first ask a question. ?What do people expect out of this? ?Do
>>> they really want support for fully segmented code, or is it just for
>>> small deviations like accessing per-thread storage through %fs/%gs?
>>>
>>
>> Prec must know the each base of segment register.
>>
>> If you don't like it. ?What about the old way that I use? ?It doesn't
>> add anything to reg list.
>> But for the each way, we need add interface to the target part that
>> prec can get the value.
>>
>> Thanks,
>> Hui
>>
>
> Ping.
>
> Thanks,
> Hui
>

Ping.

Thanks,
Hui