Gabriele Monaco [off-list ref] writes:

The RVGenerator class can find the RV directory (kernel/trace/rv) in the
kernel tree to do some auto patching. This works by assuming PWD is
either the kernel tree or tools/verification, which isn't always the
case (e.g. when running from selftests).

Make discovery more robust by relying on the absolute path of the
current script and traversing backwards the right number of times.
This should work from any location if rvgen is in the kernel tree.

Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>

With or without Thomas's suggestion:
Reviewed-by: Nam Cao <redacted>