If the leftmost parent node of the tree has does not have a child on the left side, then trie_get_next_key (and bpftool map dump) will not look at the child on the right. This leads to the traversal missing elements. Lookup is not affected. Update selftest to handle this case. Reproducer: bpftool map create /sys/fs/bpf/lpm type lpm_trie key 6 \ value 1 entries 256 name test_lpm flags 1 bpftool map update pinned /sys/fs/bpf/lpm key 8 0 0 0 0 0 value 1 bpftool map update pinned /sys/fs/bpf/lpm key 16 0 0 0 0 128 value 2 bpftool map dump pinned /sys/fs/bpf/lpm Returns only 1 element. (2 expected)
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| @@ -716,9 +716,14 @@ find_leftmost: · 715 unmodified lines | |||
| 716 | * have exact two children, so this function will never return NULL. | 716 | * have exact two children, so this function will never return NULL. |
| 717 | */ | 717 | */ |
| 718 | for (node = search_root; node;) { | 718 | for (node = search_root; node;) { |
| 719 | if (!(node->flags & LPM_TREE_NODE_FLAG_IM)) | 719 | if (node->flags & LPM_TREE_NODE_FLAG_IM) { |
| 720 | node = rcu_dereference(node->child[0]); | ||
| 721 | } else { | ||
| 720 | next_node = node; | 722 | next_node = node; |
| 721 | node = rcu_dereference(node->child[0]); | 723 | node = rcu_dereference(node->child[0]); |
| 724 | if (!node) | ||
| 725 | node = rcu_dereference(next_node->child[1]); | ||
| 726 | } | ||
| 722 | } | 727 | } |
| 723 | do_copy: | 728 | do_copy: |
| 724 | next_key->prefixlen = next_node->prefixlen; | 729 | next_key->prefixlen = next_node->prefixlen; |