Re: [PATCH v9 09/12] x86, mpx: decode MPX instruction to get bound violation information

Thomas Gleixner
2014-10-24T12:36:10Z

On Sun, 12 Oct 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.

My question still stands why using the existing decoder is an
issue. Performance is a complete non issue in case of a bounds
violation and the interface argument is just silly, really.

Thanks,

tglx