Hi Daniel,
On 01/05/2017 09:04 PM, Daniel Mack wrote:
On 01/05/2017 05:25 PM, Daniel Borkmann wrote:
On 12/29/2016 06:28 PM, Daniel Mack wrote:
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
new file mode 100644
index 0000000..8b6a61d
--- /dev/null
+++ b/kernel/bpf/lpm_trie.c
[..]
+static struct bpf_map *trie_alloc(union bpf_attr *attr)
+{
+ struct lpm_trie *trie;
+
+ /* check sanity of attributes */
+ if (attr->max_entries == 0 || attr->map_flags ||
+ attr->key_size < sizeof(struct bpf_lpm_trie_key) + 1 ||
+ attr->key_size > sizeof(struct bpf_lpm_trie_key) + 256 ||
+ attr->value_size != sizeof(u64))
+ return ERR_PTR(-EINVAL);
The correct attr->map_flags test here would need to be ...
attr->map_flags != BPF_F_NO_PREALLOC
... since in this case we don't have any prealloc pool, and
should that come one day that test could be relaxed again.
+ trie = kzalloc(sizeof(*trie), GFP_USER | __GFP_NOWARN);
+ if (!trie)
+ return NULL;
+
+ /* copy mandatory map attributes */
+ trie->map.map_type = attr->map_type;
+ trie->map.key_size = attr->key_size;
+ trie->map.value_size = attr->value_size;
+ trie->map.max_entries = attr->max_entries;
You also need to fill in trie->map.pages as that is eventually
used to charge memory against in bpf_map_charge_memlock(), right
now that would remain as 0 meaning the map is not accounted for.
Hmm, okay. The nodes are, however, allocated dynamically at runtime in
this case. That means that we have trie->map.pages on each allocation,
right?
The current scheme (f.e. htab_map_alloc() has some details, although
probably not too obvious) that was done charges worst-case cost up front,
so it would be in trie_alloc() where you fill map.pages and map_create()
will later account for them.
Thanks,
Daniel
