bndmov MPX instructions in dynamic linker breaks valgrind

[Florian Weimer]

On 08/06/2014 11:18 PM, Roland McGrath wrote:
> Because of Intel's assurance that the new opcode values are harmless NOPs,
> we didn't put any provision in the source for building a libc without the
> MPX support.

How confident are we that existing silicon is able to decode these NOPs 
efficiently?  Executing them as NOPs is just one part—if there's a 
significant performance hit, we have a problem as well.

-- 
Florian Weimer / Red Hat Product Security