Re: [PATCH 08/10] x86/xsaves: Fix PTRACE frames for XSAVES

From: Dave Hansen
Date: Mon Feb 22 2016 - 17:19:15 EST


On 02/22/2016 12:48 PM, Yu-cheng Yu wrote:
> It should have been:
>
> xsave->header.xfeatures = xfeatures |
> (xsave->header.xfeatures & XFEATURE_MASK_SUPERVISOR);
>
> I'll fix it.

Can we break it out to make it more clear?

/*
* The state that came in from userspace was user-state only.
* Mask all the user states out of 'xfeatures'.
*/
xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR;
/*
* add back in the features that came in from userspace
*/
xsave->header.xfeatures |= xfeatures