From: Hou Tao <houtao1@xxxxxxxxxx> commit 156c977c539e87e173f505b23989d7b0ec0bc7d8 upstream. When "node->prefixlen == matchlen" is true, it means that the node is fully matched. If "node->prefixlen == key->prefixlen" is false, it means the prefix length of key is greater than the prefix length of node, otherwise, matchlen will not be equal with node->prefixlen. However, it also implies that the prefix length of node must be less than max_prefixlen. Therefore, "node->prefixlen == trie->max_prefixlen" will always be false when the check of "node->prefixlen == key->prefixlen" returns false. Remove this unnecessary comparison. Reviewed-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> Acked-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx> Link: https://lore.kernel.org/r/20241206110622.1161752-2-houtao@xxxxxxxxxxxxxxx Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> Signed-off-by: Alexey Nepomnyashih <sdl@xxxxxxxx> --- kernel/bpf/lpm_trie.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index fd6e31e72290..6c96241f49a4 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -358,8 +358,7 @@ static int trie_update_elem(struct bpf_map *map, matchlen = longest_prefix_match(trie, node, key); if (node->prefixlen != matchlen || - node->prefixlen == key->prefixlen || - node->prefixlen == trie->max_prefixlen) + node->prefixlen == key->prefixlen) break; next_bit = extract_bit(key->data, node->prefixlen); -- 2.43.0
