From: Hou Tao <houtao1@huawei.com> stable inclusion from stable-v6.6.66 commit c5325e6e4b6d78827578c19e33436d1ff78449da category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBFB6E Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit eae6a075e9537dd69891cf77ca5a88fa8a28b4a1 ] Add the currently missing handling for the BPF_EXIST and BPF_NOEXIST flags. These flags can be specified by users and are relevant since LPM trie supports exact matches during update. Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") 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/20241206110622.1161752-4-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Tengda Wu <wutengda2@huawei.com> --- kernel/bpf/lpm_trie.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index daf8ffcfcdac..0b1931ad3b1d 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -368,6 +368,10 @@ static long trie_update_elem(struct bpf_map *map, * simply assign the @new_node to that slot and be done. */ if (!node) { + if (flags == BPF_EXIST) { + ret = -ENOENT; + goto out; + } rcu_assign_pointer(*slot, new_node); goto out; } @@ -376,18 +380,31 @@ static long trie_update_elem(struct bpf_map *map, * which already has the correct data array set. */ if (node->prefixlen == matchlen) { + if (!(node->flags & LPM_TREE_NODE_FLAG_IM)) { + if (flags == BPF_NOEXIST) { + ret = -EEXIST; + goto out; + } + trie->n_entries--; + } else if (flags == BPF_EXIST) { + ret = -ENOENT; + goto out; + } + new_node->child[0] = node->child[0]; new_node->child[1] = node->child[1]; - if (!(node->flags & LPM_TREE_NODE_FLAG_IM)) - trie->n_entries--; - rcu_assign_pointer(*slot, new_node); free_node = node; goto out; } + if (flags == BPF_EXIST) { + ret = -ENOENT; + goto out; + } + /* If the new node matches the prefix completely, it must be inserted * as an ancestor. Simply insert it between @node and *@slot. */ -- 2.34.1