Messages in this thread | | | Date | Thu, 17 Jul 2014 08:48:51 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] x86-64, espfix: consider IRQs are off when initializing |
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On 07/17/2014 08:13 AM, Sasha Levin wrote: > When going through our initialization code (init_espfix_ap() ) we need to > keep in mind IRQs are off, and we need to handle it appropriately: > > - Do not allocate with __GFP_FS. > - No point in using a mutex. > > Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
I don't think this is safe. The whole point was that if we do GFP_ATOMIC we have to accept failure, and if we have a spin lock then sleeping is not permitted. It is unclear to me is sleeping is safe in this context even so, so we may still have a problem, but calling __get_free_page(GFP_ATOMIC) and then unconditionally use the results is not right.
-hpa
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