Re: [PATCH] Re: SSE related security hole

Andrea Arcangeli
2002-04-20T17:27:55Z

On Sat, Apr 20, 2002 at 09:27:11AM -0700, Linus Torvalds wrote:
> If Intel makes the SSE3 registers twice as wide (or creates new ones), the
> xorps trick simply will not work.

Then the thing is different, I expected SSE3 not to mess the xmm layout.
If you just know SSE3 would break with the xorps the fxrestor way is
better. Anyways the problems I have about the implementation remains
(memset and duplicate efforts with ptrace in creating the empty fpu
state).

If they tell you the xmm registers won't change with SSE3 instead I
still prefer the xorps, that's 3bytes x 8 registers = 24 bytes of
icachce, compared to throwing away 512bytes/32 = 16 dcache cachelines so
it should be significantly faster.

Andrea