Re: [PATCH v2 net-next 4/5] bpf/verifier: remove varlen_map_value_access flag

On 08/23/2017 04:10 PM, Edward Cree wrote:

The optimisation it does is broken when the 'new' register value has a
  variable offset and the 'old' was constant.  I broke it with my pointer
  types unification (see Fixes tag below), before which the 'new' value
  would have type PTR_TO_MAP_VALUE_ADJ and would thus not compare equal;
  other changes in that patch mean that its original behaviour (ignore
  min/max values) cannot be restored.
Tests on a sample set of cilium programs show no change in count of
  processed instructions.

Fixes: f1174f77b50c ("bpf/verifier: rework value tracking")
Signed-off-by: Edward Cree <redacted>

Acked-by: Daniel Borkmann <daniel@iogearbox.net>