lkml.org 
[lkml]   [2002]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Re: SSE related security hole


On Sat, 20 Apr 2002, Andrea Arcangeli wrote:
>
> I mean, if they change the registers layout, and so if they require a
> different empty FPU state, they must as well add yet another bitflag to
> enable SSE3, if they don't the chip isn't backwards compatible.

I have unofficial confirmation from Intel that the way to architecturally
initialize the FPU state is indeed something like

memset(&fxsave, 0, sizeof(struct i387_fxsave_struct));
fxsave.cwd = 0x37f;
fxsave.mxcsr = 0x1f80;
fxrstor(&fxsave);

and the person in question is trying to make sure this is documented so
that we won't be bitten by this in the future.

Linus

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:25    [W:0.186 / U:0.740 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site