Commit 74753e14 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Andrii Nakryiko
Browse files

libbpf: Replace btf__type_by_id() with btf_type_by_id(). 



To prepare relo_core.c to be compiled in the kernel and the user space
replace btf__type_by_id with btf_type_by_id.

In libbpf btf__type_by_id and btf_type_by_id have different behavior.

bpf_core_apply_relo_insn() needs behavior of uapi btf__type_by_id
vs internal btf_type_by_id, but type_id range check is already done
in bpf_core_apply_relo(), so it's safe to replace it everywhere.
The kernel btf_type_by_id() does the check anyway. It doesn't hurt.

Suggested-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-2-alexei.starovoitov@gmail.com
parent 64b5b97b

tools/lib/bpf/btf.c

+1 −1
Original line number Diff line number Diff line
@@ -454,7 +454,7 @@ const struct btf *btf__base_btf(const struct btf *btf) 
}



/* internal helper returning non-const pointer to a type */

struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id)

struct btf_type *btf_type_by_id(const struct btf *btf, __u32 type_id)

{

	if (type_id == 0)

		return &btf_void;

tools/lib/bpf/libbpf_internal.h

+1 −1
Original line number Diff line number Diff line
@@ -172,7 +172,7 @@ static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size) 
struct btf;

struct btf_type;



struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id);

struct btf_type *btf_type_by_id(const struct btf *btf, __u32 type_id);

const char *btf_kind_str(const struct btf_type *t);

const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id);

tools/lib/bpf/relo_core.c

+8 −11
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ static bool is_flex_arr(const struct btf *btf, 
		return false;



	/* has to be the last member of enclosing struct */

	t = btf__type_by_id(btf, acc->type_id);

	t = btf_type_by_id(btf, acc->type_id);

	return acc->idx == btf_vlen(t) - 1;

}
@@ -388,7 +388,7 @@ static int bpf_core_match_member(const struct btf *local_btf, 
		return 0;



	local_id = local_acc->type_id;

	local_type = btf__type_by_id(local_btf, local_id);

	local_type = btf_type_by_id(local_btf, local_id);

	local_member = btf_members(local_type) + local_acc->idx;

	local_name = btf__name_by_offset(local_btf, local_member->name_off);
@@ -580,7 +580,7 @@ static int bpf_core_calc_field_relo(const char *prog_name, 
		return -EUCLEAN; /* request instruction poisoning */



	acc = &spec->spec[spec->len - 1];

	t = btf__type_by_id(spec->btf, acc->type_id);

	t = btf_type_by_id(spec->btf, acc->type_id);



	/* a[n] accessor needs special handling */

	if (!acc->name) {
@@ -729,7 +729,7 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo, 
	case BPF_ENUMVAL_VALUE:

		if (!spec)

			return -EUCLEAN; /* request instruction poisoning */

		t = btf__type_by_id(spec->btf, spec->spec[0].type_id);

		t = btf_type_by_id(spec->btf, spec->spec[0].type_id);

		e = btf_enum(t) + spec->spec[0].idx;

		*val = e->val;

		break;
@@ -805,8 +805,8 @@ static int bpf_core_calc_relo(const char *prog_name, 
		if (res->orig_sz != res->new_sz) {

			const struct btf_type *orig_t, *new_t;



			orig_t = btf__type_by_id(local_spec->btf, res->orig_type_id);

			new_t = btf__type_by_id(targ_spec->btf, res->new_type_id);

			orig_t = btf_type_by_id(local_spec->btf, res->orig_type_id);

			new_t = btf_type_by_id(targ_spec->btf, res->new_type_id);



			/* There are two use cases in which it's safe to

			 * adjust load/store's mem size:
@@ -1054,7 +1054,7 @@ static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec) 
	int i;



	type_id = spec->root_type_id;

	t = btf__type_by_id(spec->btf, type_id);

	t = btf_type_by_id(spec->btf, type_id);

	s = btf__name_by_offset(spec->btf, t->name_off);



	libbpf_print(level, "[%u] %s %s", type_id, btf_kind_str(t), str_is_empty(s) ? "<anon>" : s);
@@ -1158,10 +1158,7 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, 
	int i, j, err;



	local_id = relo->type_id;

	local_type = btf__type_by_id(local_btf, local_id);

	if (!local_type)

		return -EINVAL;



	local_type = btf_type_by_id(local_btf, local_id);

	local_name = btf__name_by_offset(local_btf, local_type->name_off);

	if (!local_name)

		return -EINVAL;