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Commit a316338c authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

bpf: fix wrong exposure of map_flags into fdinfo for lpm 



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: b95a5c4d ("bpf: add a longest prefix match trie map implementation")
Reported-by: default avatarJarno Rajahalme <jarno@covalent.io>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 41703a73

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;