On 08.05.2017 16:09, Thomas Garnier wrote:
Just to correct my answer here as well: Although we experimented with fixed
mappings for per-cpu addresses, the current patch does not incorporate this
yet, so it indeed still leaks. However, it is not a severe problem. The
mapping of the required (per-cpu) variables would be at a fixed location in
the user CR3, instead of the ones that are used in the kernel.
Why do you think it should be at a fixed location in the user CR3? I
see that you just mirror the entries. You also mirror
__entry_text_start / __entry_text_end which is part of the binary so
will leak the base address of the kernel. Maybe I am missing
something.
As I said, the current patch does not incorporate this yet, so yes, this part currently still leaks because we did not
implement it yet.