From cba41bb78d70aad98d8e61e019fd48c561f7f396 Mon Sep 17 00:00:00 2001 From: Rhys Rustad-Elliott Date: Fri, 2 Jun 2023 19:02:02 +0000 Subject: bpf: Fix elem_size not being set for inner maps Commit d937bc3449fa ("bpf: make uniform use of array->elem_size everywhere in arraymap.c") changed array_map_gen_lookup to use array->elem_size instead of round_up(map->value_size, 8) as the element size when generating code to access a value in an array map. array->elem_size, however, is not set by bpf_map_meta_alloc when initializing an BPF_MAP_TYPE_ARRAY_OF_MAPS or BPF_MAP_TYPE_HASH_OF_MAPS. This results in array_map_gen_lookup incorrectly outputting code that always accesses index 0 in the array (as the index will be calculated via a multiplication with the element size, which is incorrectly set to 0). Set elem_size on the bpf_array object when allocating an array or hash of maps to fix this. Fixes: d937bc3449fa ("bpf: make uniform use of array->elem_size everywhere in arraymap.c") Signed-off-by: Rhys Rustad-Elliott Link: https://lore.kernel.org/r/20230602190110.47068-2-me@rhysre.net Signed-off-by: Martin KaFai Lau --- kernel/bpf/map_in_map.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index 2c5c64c2a53b..cd5eafaba97e 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -69,9 +69,13 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) /* Misc members not needed in bpf_map_meta_equal() check. */ inner_map_meta->ops = inner_map->ops; if (inner_map->ops == &array_map_ops) { + struct bpf_array *inner_array_meta = + container_of(inner_map_meta, struct bpf_array, map); + struct bpf_array *inner_array = container_of(inner_map, struct bpf_array, map); + + inner_array_meta->index_mask = inner_array->index_mask; + inner_array_meta->elem_size = inner_array->elem_size; inner_map_meta->bypass_spec_v1 = inner_map->bypass_spec_v1; - container_of(inner_map_meta, struct bpf_array, map)->index_mask = - container_of(inner_map, struct bpf_array, map)->index_mask; } fdput(f); -- cgit v1.2.3-58-ga151