On Thu, Feb 21, 2019 at 05:39:26PM +0100, Alban Crequy wrote:
> From: Alban Crequy <al...@kinvolk.io>
>
> trie_delete_elem() was deleting an entry even though it was not matching
> if the prefixlen was correct. This patch adds a check on matchlen.
>
> Reproducer:
>
> $ sudo bpftool map create /sys/fs/bpf/mylpm type lpm_trie key 8 value 1
> entries 128 name mylpm flags 1
> $ sudo bpftool map update pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 aa bb
> cc dd value hex 01
> $ sudo bpftool map dump pinned /sys/fs/bpf/mylpm
> key: 10 00 00 00 aa bb cc dd value: 01
> Found 1 element
> $ sudo bpftool map delete pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 ff ff
> ff ff
> $ echo $?
> 0
> $ sudo bpftool map dump pinned /sys/fs/bpf/mylpm
> Found 0 elements
The change makes sense to me. Can you add this reproducer to
tools/testing/selftests/bpf/test_lpm_map.c?
Bug fix should be for the "bpf" tree instead of "bpf-next"
Fixes tag is also required, like
Fixes: e454cf595853 ("bpf: Implement map_delete_elem for BPF_MAP_TYPE_LPM_TRIE")
Cc: Craig Gallek <kr...@google.com>
>
> Signed-off-by: Alban Crequy <al...@kinvolk.io>
> ---
> kernel/bpf/lpm_trie.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
> index abf1002080df..93a5cbbde421 100644
> --- a/kernel/bpf/lpm_trie.c
> +++ b/kernel/bpf/lpm_trie.c
> @@ -471,6 +471,7 @@ static int trie_delete_elem(struct bpf_map *map, void
> *_key)
> }
>
> if (!node || node->prefixlen != key->prefixlen ||
> + node->prefixlen != matchlen ||
> (node->flags & LPM_TREE_NODE_FLAG_IM)) {
> ret = -ENOENT;
> goto out;
> --
> 2.20.1
>
