On 03/22/2017 06:00 PM, Martin KaFai Lau wrote:
Fix in verifier: For the same bpf_map_lookup_elem() instruction (i.e. "call 1"), a broken case is "a different type of map could be used for the same lookup instruction". For example, an array in one case and a hashmap in another. We have to resort to the old dynamic call behavior in this case. The fix is to check for collision on insn_aux->map_ptr. If there is collision, don't inline the map lookup.Please see the "do_reg_lookup()" in test_map_in_map_kern.c in the later patch for how-to trigger the above case. Simplifications on array_map_gen_lookup(): 1. Calculate elem_size from map->value_size. It removes the need for 'struct bpf_array' which makes the later map-in-map implementation easier. 2. Remove the 'elem_size == 1' test Fixes: 81ed18ab3098 ("bpf: add helper inlining infra and optimize map_array lookup") Signed-off-by: Martin KaFai Lau <ka...@fb.com> Acked-by: Alexei Starovoitov <a...@kernel.org>
Ok, makes sense (could have been split into two actually). Acked-by: Daniel Borkmann <dan...@iogearbox.net>
