Re: [Xen-devel] [PATCH] Choose retpoline only when it is safe to use

[Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx>]

在 2018/2/6 16:59, Andrew Cooper 写道:
> On 06/02/2018 08:43, Zhenzhong Duan wrote:
> > When ( ibrs && thunk == THUNK_DEFAULT && !retpoline_safe() ) is true,
> > thunk is set to THUNK_JMP rather than THUNK_RETPOLINE.
> >
> > When (!ibrs && thunk == THUNK_DEFAULT && !retpoline_safe() ) is true,
> > we should do the same.
> >
> > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx>
> Why?  What improvement is this intended to give?
No improvement, I just feel if retpoline isn't safe, THUNK_JMP is better 
and safer.
Above first check is working that way.
> (IOW, the logic here is deliberate, and has a specific purpose.)
Ok, Just ignore the noise if it's deliberate.

--
thanks
zduan


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