Commit 95678395 authored by Kui-Feng Lee's avatar Kui-Feng Lee Committed by Martin KaFai Lau
Browse files

bpf: get type information with BTF_ID_LIST 



Get ready to remove bpf_struct_ops_init() in the future. By using
BTF_ID_LIST, it is possible to gather type information while building
instead of runtime.

Signed-off-by: default avatarKui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240119225005.668602-3-thinker.li@gmail.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 3b1f89e7

kernel/bpf/bpf_struct_ops.c

+8 −9
Original line number Diff line number Diff line
@@ -108,7 +108,12 @@ const struct bpf_prog_ops bpf_struct_ops_prog_ops = { 
#endif

};



static const struct btf_type *module_type;

BTF_ID_LIST(st_ops_ids)

BTF_ID(struct, module)



enum {

	IDX_MODULE_ID,

};



static void bpf_struct_ops_init_one(struct bpf_struct_ops *st_ops,

				    struct btf *btf,
@@ -197,7 +202,6 @@ static void bpf_struct_ops_init_one(struct bpf_struct_ops *st_ops, 
void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)

{

	struct bpf_struct_ops *st_ops;

	s32 module_id;

	u32 i;



	/* Ensure BTF type is emitted for "struct bpf_struct_ops_##_name" */
@@ -205,13 +209,6 @@ void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log) 
#include "bpf_struct_ops_types.h"

#undef BPF_STRUCT_OPS_TYPE



	module_id = btf_find_by_name_kind(btf, "module", BTF_KIND_STRUCT);

	if (module_id < 0) {

		pr_warn("Cannot find struct module in %s\n", btf_get_name(btf));

		return;

	}

	module_type = btf_type_by_id(btf, module_id);



	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {

		st_ops = bpf_struct_ops[i];

		bpf_struct_ops_init_one(st_ops, btf, log);
@@ -387,6 +384,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, 
	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;

	const struct bpf_struct_ops *st_ops = st_map->st_ops;

	struct bpf_struct_ops_value *uvalue, *kvalue;

	const struct btf_type *module_type;

	const struct btf_member *member;

	const struct btf_type *t = st_ops->type;

	struct bpf_tramp_links *tlinks;
@@ -434,6 +432,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, 
	image = st_map->image;

	image_end = st_map->image + PAGE_SIZE;



	module_type = btf_type_by_id(btf_vmlinux, st_ops_ids[IDX_MODULE_ID]);

	for_each_member(i, t, member) {

		const struct btf_type *mtype, *ptype;

		struct bpf_prog *prog;