Messages in this thread | | | Date | Thu, 1 Mar 2018 17:50:19 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 12/31] x86/entry/32: Add PTI cr3 switch to non-NMI entry/exit points |
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On Thu, Mar 01, 2018 at 09:33:11AM -0500, Waiman Long wrote: > On 03/01/2018 08:34 AM, Joerg Roedel wrote: > I think that should fix the issue of debug exception from userspace. > > One thing that I am not certain about is whether debug exception can > happen even if the IF flag is cleared. If it can, debug exception should > be handled like NMI as the state of the CR3 can be indeterminate if the > exception happens in the entry/exit code.
I am actually not 100% sure where it can happen, from the code it can happen from anywhere, except when we are running on an espfix stack.
So I am not sure we need the same complex handling NMIs need wrt. to switching the cr3s.
Joerg
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