Re: [PATCH v4 0/10] x86/xsaves: Fix XSAVES known issues

[Dave Hansen]

On 04/29/2016 01:07 PM, Yu-cheng Yu wrote:
> On Fri, Apr 29, 2016 at 01:03:43PM -0700, Dave Hansen wrote:
>>> That's not feasible.  Think of dynamic libraries or just-in-time 
>>> compilers.  What instruction set does /usr/bin/java use, for
>>> instance? :)
> The java argument is true. In that case or when the bitmask is
> missing, we can allocate for all supported features.

Remember, execve() doesn't replace the task_struct.  How do we resize
the task_struct at execve() time?  If /bin/bash doesn't use AVX, then
fork()s and execve()s an AVX-using program, what do we do?