Re: [PATCH v8 07/10] x86, mpx: decode MPX instruction to get bound violation information

From: Thomas Gleixner
Date: Thu Sep 11 2014 - 18:18:31 EST


On Thu, 11 Sep 2014, Qiaowei Ren wrote:

> This patch sets bound violation fields of siginfo struct in #BR
> exception handler by decoding the user instruction and constructing
> the faulting pointer.
>
> This patch does't use the generic decoder, and implements a limited
> special-purpose decoder to decode MPX instructions, simply because the
> generic decoder is very heavyweight not just in terms of performance
> but in terms of interface -- because it has to.

And why is that an argument to add another special purpose decoder?

If a bound violation happens it is completely irrelevant whether the
decoder is heavyweight or not.

So unless you come up with a convincing argument why the generic
decoder is the wrong place, this won't happen.

Thanks,

tglx
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