lkml.org 
[lkml]   [2019]   [Jan]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 15/22] x86/entry: Add TIF_NEED_FPU_LOAD
On Wed, Jan 09, 2019 at 12:47:37PM +0100, Sebastian Andrzej Siewior wrote:
> Add TIF_NEED_FPU_LOAD. This is reserved for loading the FPU registers
> before returning to userland. This flag must not be set for systems
> without a FPU.
> If this flag is cleared, the CPU's FPU register hold the current content
> of current()'s FPU register. The in-memory copy (union fpregs_state) is
> not valid.
> If this flag is set, then all of CPU's FPU register may hold a random
> value (except for PKRU) and it is required to load the content of the
> FPU register on return to userland.

This definitely needs to be written somewhere in

arch/x86/include/asm/fpu/internal.h

or where we decide to put the FPU handling rules.

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

\
 
 \ /
  Last update: 2019-01-30 12:57    [W:0.562 / U:0.308 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site