Messages in this thread | | | Date | Thu, 24 Jul 2008 13:27:28 -0700 | From | Suresh Siddha <> | Subject | Re: [patch] x64, fpu: fix possible FPU leakage in error conditions |
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On Thu, Jul 24, 2008 at 11:59:03AM -0700, Linus Torvalds wrote: > > On Thu, 24 Jul 2008, Suresh Siddha wrote: > > > > If we don't do init_fpu() + restore from the sane init state, process has > > to be killed, in the paranoid failing scenario of math_state_restore() > > Umm. I'm still not seeing why the right answer is not just to do "stts + > math_used = 0". > > And the specific case of math_state_restore(), that will also fix the > problem - next time around.
Ok.
> As far as I can tell, your patch causes serious problems in case > init_fpu() fails. Which it can do, afaik.
Only the first init_fpu() can fail (memory allocation failure). But here, it is def not the first time.
Anyhow, your suggestion is simple and clean. Will post the patch shortly.
I have to do clear_fpu() though(stts + math_used = 0 may not be enough).
thanks, suresh
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