bpf: fix wrong exposure of map_flags into fdinfo for lpm (a316338c) · Commits · 戴 / test

trie_alloc() always needs to have BPF_F_NO_PREALLOC passed in via attr->map_flags, since it does not support preallocation yet. We check the flag, but we never copy the flag into trie->map.map_flags, which is later on exposed into fdinfo and used by loaders such as iproute2. Latter uses this in bpf_map_selfcheck_pinned() to test whether a pinned map has the same spec as the one from the BPF obj file and if not, bails out, which is currently the case for lpm since it exposes always 0 as flags. Also copy over flags in array_map_alloc() and stack_map_alloc(). They always have to be 0 right now, but we should make sure to not miss to copy them over at a later point in time when we add actual flags for them to use. Fixes: ("bpf: add a longest prefix match trie map implementation") Reported-by:

Jarno Rajahalme <jarno@covalent.io> Signed-off-by:

Daniel Borkmann <daniel@iogearbox.net> Acked-by:

Alexei Starovoitov <ast@kernel.org> Signed-off-by:

David S. Miller <davem@davemloft.net>

kernel/bpf/arraymap.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,7 @@ static struct bpf_map array_map_alloc(union bpf_attr attr)
		array->map.key_size = attr->key_size;
		array->map.value_size = attr->value_size;
		array->map.max_entries = attr->max_entries;
		array->map.map_flags = attr->map_flags;
		array->elem_size = elem_size;

		if (!percpu)

kernel/bpf/lpm_trie.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -432,6 +432,7 @@ static struct bpf_map trie_alloc(union bpf_attr attr)
		trie->map.key_size = attr->key_size;
		trie->map.value_size = attr->value_size;
		trie->map.max_entries = attr->max_entries;
		trie->map.map_flags = attr->map_flags;
		trie->data_size = attr->key_size -
		offsetof(struct bpf_lpm_trie_key, data);
		trie->max_prefixlen = trie->data_size * 8;

kernel/bpf/stackmap.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -88,6 +88,7 @@ static struct bpf_map stack_map_alloc(union bpf_attr attr)
		smap->map.key_size = attr->key_size;
		smap->map.value_size = value_size;
		smap->map.max_entries = attr->max_entries;
		smap->map.map_flags = attr->map_flags;
		smap->n_buckets = n_buckets;
		smap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;

Admin message