Commit 7723256b authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

libbpf: Introduce bpf_map__initial_value(). 



Introduce bpf_map__initial_value() to read initial contents
of mmaped data/rodata/bss maps.
Note that bpf_map__set_initial_value() doesn't allow modifying
kconfig map while bpf_map__initial_value() allows reading
its values.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-17-alexei.starovoitov@gmail.com
parent 30f51aed

tools/lib/bpf/libbpf.c

+8 −0
Original line number Diff line number Diff line
@@ -9755,6 +9755,14 @@ int bpf_map__set_initial_value(struct bpf_map *map, 
	return 0;

}



const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize)

{

	if (!map->mmaped)

		return NULL;

	*psize = map->def.value_size;

	return map->mmaped;

}



bool bpf_map__is_offload_neutral(const struct bpf_map *map)

{

	return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;

tools/lib/bpf/libbpf.h

+1 −0
Original line number Diff line number Diff line
@@ -471,6 +471,7 @@ LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv, 
LIBBPF_API void *bpf_map__priv(const struct bpf_map *map);

LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,

					  const void *data, size_t size);

LIBBPF_API const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);

LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);

LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);

LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);

tools/lib/bpf/libbpf.map

+1 −0
Original line number Diff line number Diff line
@@ -359,6 +359,7 @@ LIBBPF_0.4.0 { 
		bpf_linker__finalize;

		bpf_linker__free;

		bpf_linker__new;

		bpf_map__initial_value;

		bpf_map__inner_map;

		bpf_object__gen_loader;

		bpf_object__set_kversion;