diff options
| author | Hou Tao <houtao1@huawei.com> | 2024-12-06 19:06:14 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-12-06 09:14:25 -0800 |
| commit | 156c977c539e87e173f505b23989d7b0ec0bc7d8 (patch) | |
| tree | 1b3e5077c8522fe8112b843a9b54a8e593c4d06b | |
| parent | e2cf913314b9543f4479788443c7e9009c6c56d8 (diff) | |
bpf: Remove unnecessary check when updating LPM trie
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@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241206110622.1161752-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | kernel/bpf/lpm_trie.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index 9b60eda0f727..73fd593d3745 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -364,8 +364,7 @@ static long 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); |