bpf: Relax max_entries check for most of the inner map types

Most of the maps do not use max_entries during verification time.
Thus, those map_meta_equal() do not need to enforce max_entries
when it is inserted as an inner map during runtime.  The max_entries
check is removed from the default implementation bpf_map_meta_equal().

The prog_array_map and xsk_map are exception.  Its map_gen_lookup
uses max_entries to generate inline lookup code.  Thus, they will
implement its own map_meta_equal() to enforce max_entries.
Since there are only two cases now, the max_entries check
is not refactored and stays in its own .c file.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200828011813.1970516-1-kafai@fb.com
This commit is contained in:
Martin KaFai Lau
2020-08-27 18:18:13 -07:00
committed by Daniel Borkmann
parent f4d0525921
commit 134fede4ee
3 changed files with 17 additions and 4 deletions

View File

@@ -75,8 +75,7 @@ bool bpf_map_meta_equal(const struct bpf_map *meta0,
return meta0->map_type == meta1->map_type &&
meta0->key_size == meta1->key_size &&
meta0->value_size == meta1->value_size &&
meta0->map_flags == meta1->map_flags &&
meta0->max_entries == meta1->max_entries;
meta0->map_flags == meta1->map_flags;
}
void *bpf_map_fd_get_ptr(struct bpf_map *map,