Re: [PATCH 12/31] x86/entry/32: Add PTI cr3 switch to non-NMI entry/exit points

[Dave Hansen]

On 03/01/2018 10:24 AM, Brian Gerst wrote:
> 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.

It can happen with IF cleared.  I ran into it during PTI development
more than once.  That's why the debug fault code uses paranoid_entry on
64-bit just like the NMI code.