[PATCH bpf-next 4/6] bpftool: Support 24-bit vlen

Alan Maguire
2026-04-14T19:51:09Z

Adjust btf_vlen() usage to handle 24-bit vlen.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
---
tools/bpf/bpftool/btf.c | 17 ++++++-----------
tools/bpf/bpftool/gen.c | 16 +++++++++-------
2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index 2e899e940034..6ef908adf3a4 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -179,8 +179,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
case BTF_KIND_STRUCT:
case BTF_KIND_UNION: {
const struct btf_member *m = (const void *)(t + 1);
- __u16 vlen = BTF_INFO_VLEN(t->info);
- int i;
+ __u32 i, vlen = BTF_INFO_VLEN(t->info);

if (json_output) {
jsonw_uint_field(w, "size", t->size);
@@ -225,9 +224,8 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
}
case BTF_KIND_ENUM: {
const struct btf_enum *v = (const void *)(t + 1);
- __u16 vlen = BTF_INFO_VLEN(t->info);
+ __u32 i, vlen = BTF_INFO_VLEN(t->info);
const char *encoding;
- int i;

encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
if (json_output) {
@@ -263,9 +261,8 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
}
case BTF_KIND_ENUM64: {
const struct btf_enum64 *v = btf_enum64(t);
- __u16 vlen = btf_vlen(t);
+ __u32 i, vlen = btf_vlen(t);
const char *encoding;
- int i;

encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
if (json_output) {
@@ -325,8 +322,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
}
case BTF_KIND_FUNC_PROTO: {
const struct btf_param *p = (const void *)(t + 1);
- __u16 vlen = BTF_INFO_VLEN(t->info);
- int i;
+ __u32 i, vlen = BTF_INFO_VLEN(t->info);

if (json_output) {
jsonw_uint_field(w, "ret_type_id", t->type);
@@ -369,8 +365,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
case BTF_KIND_DATASEC: {
const struct btf_var_secinfo *v = (const void *)(t + 1);
const struct btf_type *vt;
- __u16 vlen = BTF_INFO_VLEN(t->info);
- int i;
+ __u32 i, vlen = BTF_INFO_VLEN(t->info);

if (json_output) {
jsonw_uint_field(w, "size", t->size);
@@ -675,7 +670,7 @@ static __u64 btf_name_hasher(__u64 hash, const struct btf *btf, __u32 name_off)
static __u64 btf_type_disambig_hash(const struct btf *btf, __u32 id, bool include_members)
{
const struct btf_type *t = btf__type_by_id(btf, id);
- int i;
+ __u32 i;
size_t hash = 0;

hash = btf_name_hasher(hash, btf, t->name_off);
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 2f9e10752e28..def7497e39c9 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -2094,7 +2094,8 @@ btfgen_mark_type(struct btfgen_info *info, unsigned int type_id, bool follow_poi
struct btf_type *cloned_type;
struct btf_param *param;
struct btf_array *array;
- int err, i;
+ __u32 i;
+ int err;

if (type_id == 0)
return 0;
@@ -2229,7 +2230,8 @@ static int btfgen_mark_type_match(struct btfgen_info *info, __u32 type_id, bool
const struct btf_type *btf_type;
struct btf *btf = info->src_btf;
struct btf_type *cloned_type;
- int i, err;
+ int err;
+ __u32 i;

if (type_id == 0)
return 0;
@@ -2249,7 +2251,7 @@ static int btfgen_mark_type_match(struct btfgen_info *info, __u32 type_id, bool
case BTF_KIND_STRUCT:
case BTF_KIND_UNION: {
struct btf_member *m = btf_members(btf_type);
- __u16 vlen = btf_vlen(btf_type);
+ __u32 vlen = btf_vlen(btf_type);

if (behind_ptr)
break;
@@ -2286,7 +2288,7 @@ static int btfgen_mark_type_match(struct btfgen_info *info, __u32 type_id, bool
break;
}
case BTF_KIND_FUNC_PROTO: {
- __u16 vlen = btf_vlen(btf_type);
+ __u32 vlen = btf_vlen(btf_type);
struct btf_param *param;

/* mark ret type */
@@ -2492,8 +2494,9 @@ static struct btf *btfgen_get_btf(struct btfgen_info *info)
{
struct btf *btf_new = NULL;
unsigned int *ids = NULL;
- unsigned int i, n = btf__type_cnt(info->marked_btf);
+ unsigned int n = btf__type_cnt(info->marked_btf);
int err = 0;
+ __u32 i;

btf_new = btf__new_empty();
if (!btf_new) {
@@ -2523,8 +2526,7 @@ static struct btf *btfgen_get_btf(struct btfgen_info *info)
/* add members for struct and union */
if (btf_is_composite(type)) {
struct btf_member *cloned_m, *m;
- unsigned short vlen;
- int idx_src;
+ unsigned int vlen, idx_src;

name = btf__str_by_offset(info->src_btf, type->name_off);

--
2.39.3