Re: [PATCH] Re: SSE related security hole

Linus Torvalds (torvalds@transmeta.com)
Sat, 20 Apr 2002 10:38:59 -0700 (PDT)


On Sat, 20 Apr 2002, Andrea Arcangeli wrote:
>
> 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).

Hey, send a clean patch and it will definitely get fixed.. I don't
disagree with that part, although actual numbers are always good to have.

> 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.

Oh, if they promise to not add registers we have an easy time, I agree.

Linus

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