Commit 6a886de0 authored by Hengqi Chen's avatar Hengqi Chen Committed by Andrii Nakryiko
Browse files

libbpf: Add btf__type_cnt() and btf__raw_data() APIs 

Add btf__type_cnt() and btf__raw_data() APIs and deprecate
btf__get_nr_type() and btf__get_raw_data() since the old APIs
don't follow the libbpf naming convention for getters which
omit 'get' in the name (see [0]). btf__raw_data() is just an
alias to the existing btf__get_raw_data(). btf__type_cnt()
now returns the number of all types of the BTF object
including 'void'.

  [0] Closes: https://github.com/libbpf/libbpf/issues/279



Signed-off-by: default avatarHengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022130623.1548429-2-hengqi.chen@gmail.com
parent 1000298c

tools/lib/bpf/btf.c

+22 −14
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ struct btf { 
	 * representation is broken up into three independently allocated

	 * memory regions to be able to modify them independently.

	 * raw_data is nulled out at that point, but can be later allocated

	 * and cached again if user calls btf__get_raw_data(), at which point

	 * and cached again if user calls btf__raw_data(), at which point

	 * raw_data will contain a contiguous copy of header, types, and

	 * strings:

	 *
@@ -435,6 +435,11 @@ __u32 btf__get_nr_types(const struct btf *btf) 
	return btf->start_id + btf->nr_types - 1;

}



__u32 btf__type_cnt(const struct btf *btf)

{

	return btf->start_id + btf->nr_types;

}



const struct btf *btf__base_btf(const struct btf *btf)

{

	return btf->base_btf;
@@ -466,8 +471,8 @@ static int determine_ptr_size(const struct btf *btf) 
	if (btf->base_btf && btf->base_btf->ptr_sz > 0)

		return btf->base_btf->ptr_sz;



	n = btf__get_nr_types(btf);

	for (i = 1; i <= n; i++) {

	n = btf__type_cnt(btf);

	for (i = 1; i < n; i++) {

		t = btf__type_by_id(btf, i);

		if (!btf_is_int(t))

			continue;
@@ -684,12 +689,12 @@ int btf__resolve_type(const struct btf *btf, __u32 type_id) 


__s32 btf__find_by_name(const struct btf *btf, const char *type_name)

{

	__u32 i, nr_types = btf__get_nr_types(btf);

	__u32 i, nr_types = btf__type_cnt(btf);



	if (!strcmp(type_name, "void"))

		return 0;



	for (i = 1; i <= nr_types; i++) {

	for (i = 1; i < nr_types; i++) {

		const struct btf_type *t = btf__type_by_id(btf, i);

		const char *name = btf__name_by_offset(btf, t->name_off);
@@ -703,12 +708,12 @@ __s32 btf__find_by_name(const struct btf *btf, const char *type_name) 
static __s32 btf_find_by_name_kind(const struct btf *btf, int start_id,

				   const char *type_name, __u32 kind)

{

	__u32 i, nr_types = btf__get_nr_types(btf);

	__u32 i, nr_types = btf__type_cnt(btf);



	if (kind == BTF_KIND_UNKN || !strcmp(type_name, "void"))

		return 0;



	for (i = start_id; i <= nr_types; i++) {

	for (i = start_id; i < nr_types; i++) {

		const struct btf_type *t = btf__type_by_id(btf, i);

		const char *name;
@@ -781,7 +786,7 @@ static struct btf *btf_new_empty(struct btf *base_btf) 


	if (base_btf) {

		btf->base_btf = base_btf;

		btf->start_id = btf__get_nr_types(base_btf) + 1;

		btf->start_id = btf__type_cnt(base_btf);

		btf->start_str_off = base_btf->hdr->str_len;

	}
@@ -831,7 +836,7 @@ static struct btf *btf_new(const void *data, __u32 size, struct btf *base_btf) 


	if (base_btf) {

		btf->base_btf = base_btf;

		btf->start_id = btf__get_nr_types(base_btf) + 1;

		btf->start_id = btf__type_cnt(base_btf);

		btf->start_str_off = base_btf->hdr->str_len;

	}
@@ -1224,7 +1229,7 @@ static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endi 
	return NULL;

}



const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size)

const void *btf__raw_data(const struct btf *btf_ro, __u32 *size)

{

	struct btf *btf = (struct btf *)btf_ro;

	__u32 data_sz;
@@ -1232,7 +1237,7 @@ const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size) 


	data = btf_get_raw_data(btf, &data_sz, btf->swapped_endian);

	if (!data)

		return errno = -ENOMEM, NULL;

		return errno = ENOMEM, NULL;



	btf->raw_size = data_sz;

	if (btf->swapped_endian)
@@ -1243,6 +1248,9 @@ const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size) 
	return data;

}



__attribute__((alias("btf__raw_data")))

const void *btf__get_raw_data(const struct btf *btf, __u32 *size);



const char *btf__str_by_offset(const struct btf *btf, __u32 offset)

{

	if (offset < btf->start_str_off)
@@ -1651,7 +1659,7 @@ int btf__add_btf(struct btf *btf, const struct btf *src_btf) 
	old_strs_len = btf->hdr->str_len;



	data_sz = src_btf->hdr->type_len;

	cnt = btf__get_nr_types(src_btf);

	cnt = btf__type_cnt(src_btf) - 1;



	/* pre-allocate enough memory for new types */

	t = btf_add_type_mem(btf, data_sz);
@@ -1968,7 +1976,7 @@ int btf__add_union(struct btf *btf, const char *name, __u32 byte_sz) 


static struct btf_type *btf_last_type(struct btf *btf)

{

	return btf_type_by_id(btf, btf__get_nr_types(btf));

	return btf_type_by_id(btf, btf__type_cnt(btf) - 1);

}



/*
@@ -3174,7 +3182,7 @@ static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext, 
		goto done;

	}



	type_cnt = btf__get_nr_types(btf) + 1;

	type_cnt = btf__type_cnt(btf);

	d->map = malloc(sizeof(__u32) * type_cnt);

	if (!d->map) {

		err = -ENOMEM;

tools/lib/bpf/btf.h

+4 −0
Original line number Diff line number Diff line
@@ -132,7 +132,9 @@ LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, 
				   const char *type_name);

LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,

					const char *type_name, __u32 kind);

LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__type_cnt() instead; note that btf__get_nr_types() == btf__type_cnt() - 1")

LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);

LIBBPF_API __u32 btf__type_cnt(const struct btf *btf);

LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);

LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,

						  __u32 id);
@@ -145,7 +147,9 @@ LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); 
LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);

LIBBPF_API int btf__fd(const struct btf *btf);

LIBBPF_API void btf__set_fd(struct btf *btf, int fd);

LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__raw_data() instead")

LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);

LIBBPF_API const void *btf__raw_data(const struct btf *btf, __u32 *size);

LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);

LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);

LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,

tools/lib/bpf/btf_dump.c

+4 −4
Original line number Diff line number Diff line
@@ -188,7 +188,7 @@ struct btf_dump *btf_dump__new(const struct btf *btf, 


static int btf_dump_resize(struct btf_dump *d)

{

	int err, last_id = btf__get_nr_types(d->btf);

	int err, last_id = btf__type_cnt(d->btf) - 1;



	if (last_id <= d->last_id)

		return 0;
@@ -262,7 +262,7 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id) 
{

	int err, i;



	if (id > btf__get_nr_types(d->btf))

	if (id >= btf__type_cnt(d->btf))

		return libbpf_err(-EINVAL);



	err = btf_dump_resize(d);
@@ -294,11 +294,11 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id) 
 */

static int btf_dump_mark_referenced(struct btf_dump *d)

{

	int i, j, n = btf__get_nr_types(d->btf);

	int i, j, n = btf__type_cnt(d->btf);

	const struct btf_type *t;

	__u16 vlen;



	for (i = d->last_id + 1; i <= n; i++) {

	for (i = d->last_id + 1; i < n; i++) {

		t = btf__type_by_id(d->btf, i);

		vlen = btf_vlen(t);

tools/lib/bpf/libbpf.c

+18 −18
Original line number Diff line number Diff line
@@ -2497,8 +2497,8 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict, 
		return -EINVAL;

	}



	nr_types = btf__get_nr_types(obj->btf);

	for (i = 1; i <= nr_types; i++) {

	nr_types = btf__type_cnt(obj->btf);

	for (i = 1; i < nr_types; i++) {

		t = btf__type_by_id(obj->btf, i);

		if (!btf_is_datasec(t))

			continue;
@@ -2579,7 +2579,7 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) 
	struct btf_type *t;

	int i, j, vlen;



	for (i = 1; i <= btf__get_nr_types(btf); i++) {

	for (i = 1; i < btf__type_cnt(btf); i++) {

		t = (struct btf_type *)btf__type_by_id(btf, i);



		if ((!has_datasec && btf_is_var(t)) || (!has_decl_tag && btf_is_decl_tag(t))) {
@@ -2763,9 +2763,9 @@ static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf, 
static int btf_finalize_data(struct bpf_object *obj, struct btf *btf)

{

	int err = 0;

	__u32 i, n = btf__get_nr_types(btf);

	__u32 i, n = btf__type_cnt(btf);



	for (i = 1; i <= n; i++) {

	for (i = 1; i < n; i++) {

		struct btf_type *t = btf_type_by_id(btf, i);



		/* Loader needs to fix up some of the things compiler
@@ -2905,8 +2905,8 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) 
		if (!prog->mark_btf_static || !prog_is_subprog(obj, prog))

			continue;



		n = btf__get_nr_types(obj->btf);

		for (j = 1; j <= n; j++) {

		n = btf__type_cnt(obj->btf);

		for (j = 1; j < n; j++) {

			t = btf_type_by_id(obj->btf, j);

			if (!btf_is_func(t) || btf_func_linkage(t) != BTF_FUNC_GLOBAL)

				continue;
@@ -2926,7 +2926,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) 
		__u32 sz;



		/* clone BTF to sanitize a copy and leave the original intact */

		raw_data = btf__get_raw_data(obj->btf, &sz);

		raw_data = btf__raw_data(obj->btf, &sz);

		kern_btf = btf__new(raw_data, sz);

		err = libbpf_get_error(kern_btf);

		if (err)
@@ -2939,7 +2939,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) 


	if (obj->gen_loader) {

		__u32 raw_size = 0;

		const void *raw_data = btf__get_raw_data(kern_btf, &raw_size);

		const void *raw_data = btf__raw_data(kern_btf, &raw_size);



		if (!raw_data)

			return -ENOMEM;
@@ -3350,8 +3350,8 @@ static int find_extern_btf_id(const struct btf *btf, const char *ext_name) 
	if (!btf)

		return -ESRCH;



	n = btf__get_nr_types(btf);

	for (i = 1; i <= n; i++) {

	n = btf__type_cnt(btf);

	for (i = 1; i < n; i++) {

		t = btf__type_by_id(btf, i);



		if (!btf_is_var(t) && !btf_is_func(t))
@@ -3382,8 +3382,8 @@ static int find_extern_sec_btf_id(struct btf *btf, int ext_btf_id) { 
	if (!btf)

		return -ESRCH;



	n = btf__get_nr_types(btf);

	for (i = 1; i <= n; i++) {

	n = btf__type_cnt(btf);

	for (i = 1; i < n; i++) {

		t = btf__type_by_id(btf, i);



		if (!btf_is_datasec(t))
@@ -3467,8 +3467,8 @@ static int find_int_btf_id(const struct btf *btf) 
	const struct btf_type *t;

	int i, n;



	n = btf__get_nr_types(btf);

	for (i = 1; i <= n; i++) {

	n = btf__type_cnt(btf);

	for (i = 1; i < n; i++) {

		t = btf__type_by_id(btf, i);



		if (btf_is_int(t) && btf_int_bits(t) == 32)
@@ -5076,8 +5076,8 @@ static int bpf_core_add_cands(struct bpf_core_cand *local_cand, 
	size_t targ_essent_len;

	int n, i;



	n = btf__get_nr_types(targ_btf);

	for (i = targ_start_id; i <= n; i++) {

	n = btf__type_cnt(targ_btf);

	for (i = targ_start_id; i < n; i++) {

		t = btf__type_by_id(targ_btf, i);

		if (btf_kind(t) != btf_kind(local_cand->t))

			continue;
@@ -5252,7 +5252,7 @@ bpf_core_find_cands(struct bpf_object *obj, const struct btf *local_btf, __u32 l 
		err = bpf_core_add_cands(&local_cand, local_essent_len,

					 obj->btf_modules[i].btf,

					 obj->btf_modules[i].name,

					 btf__get_nr_types(obj->btf_vmlinux) + 1,

					 btf__type_cnt(obj->btf_vmlinux),

					 cands);

		if (err)

			goto err_out;

tools/lib/bpf/libbpf.map

+2 −0
Original line number Diff line number Diff line
@@ -395,4 +395,6 @@ LIBBPF_0.6.0 { 
		bpf_object__prev_program;

		btf__add_btf;

		btf__add_decl_tag;

		btf__raw_data;

		btf__type_cnt;

} LIBBPF_0.5.0;