On Thu, Mar 21, 2019 at 09:33:17AM +0100, Peter Zijlstra wrote:
I'm thinking this problem wasn't new.
> idtentry page_fault do_page_fault has_error_code=1
> call error_entry
> TRACE_IRQS_OFF
> call trace_hardirqs_off*
> <tracer stuff>
> <fault> # modifies CR2
CALL_enter_from_user_mode
__context_tracking_exit()
trace_user_exit(0)
#PF
> call do_page_fault
> address = read_cr2(); /* whoopsie */
And that also isn't fixed by your patch.
I'm trying to make idtentry put cr2 in rdx, such that do_page_fault()
takes address as a 3rd argument, but I'm still fighting that context
tracking nonsense.
