Messages in this thread | | | Date | Sun, 11 Feb 2001 21:30:53 +0100 | From | Manfred Spraul <> | Subject | Re: [RFC] framework for fpu usage in kernel |
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Alan Cox wrote: > > > memcopy is a really generic function, and calling it saves the current > > fpu state into thread.i387.f{,x}save. IMHO that's wrong, memcopy must > > save into a local buffer like raid5 checksumming. > > The mmx copy is only done in task context. There are a whole variety > of _horrible_ problems doing it in interrupt space so based on the > considerable number of problems with prior attempts to get it right on > IRQ and copyuser cases I didnt bother > Even task context is dangerous:
What if a drm module wants to use the fpu and then uses memcpy() after modifying the ftp registers?
-- Manfred - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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