Re: [PATCH] Make math_state_restore() save and restore the interrupt flag

From: Linus Torvalds
Date: Sat Feb 01 2014 - 20:38:36 EST


On Sat, Feb 1, 2014 at 5:35 PM, Suresh Siddha <sbsiddha@xxxxxxxxx> wrote:
> On Sat, Feb 1, 2014 at 5:26 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
>> Even "b" does that, no?
>
> oh right. It needs an else. only for non-eager fpu case we should do stts()

It definitely does not want an else, I think.

If tsk_used_math() is false, or if the FPU restore failed, we
*definitely* need that stts(). Otherwise we'd return to user mode with
random contents in the FP state, and let user mode muck around with
it.

No?

Linus
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