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: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022130623.1548429-2-hengqi.chen@gmail.com
This commit is contained in:
Hengqi Chen
2021-10-22 21:06:19 +08:00
committed by Andrii Nakryiko
parent eb10610a3b
commit 596c9a2d77
6 changed files with 64 additions and 50 deletions

View File

@@ -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 @@ err_out:
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;