[PATCH bpf-next v3 2/6] resolve_btfids: Factor out load_btf()

Ihor Solodrai
2025-12-05T22:31:48Z

Increase the lifetime of parsed BTF in resolve_btfids by factoring
load_btf() routine out of symbols_resolve() and storing the base_btf
and btf pointers in the struct object.

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
---
tools/bpf/resolve_btfids/main.c | 47 ++++++++++++++++++++++++---------
1 file changed, 34 insertions(+), 13 deletions(-)

diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index 164f0c941f04..b4caae1170dd 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -116,6 +116,9 @@ struct object {
const char *btf_path;
const char *base_btf_path;

+ struct btf *btf;
+ struct btf *base_btf;
+
struct {
int fd;
Elf *elf;
@@ -529,16 +532,10 @@ static int symbols_collect(struct object *obj)
return 0;
}

-static int symbols_resolve(struct object *obj)
+static int load_btf(struct object *obj)
{
- int nr_typedefs = obj->nr_typedefs;
- int nr_structs = obj->nr_structs;
- int nr_unions = obj->nr_unions;
- int nr_funcs = obj->nr_funcs;
- struct btf *base_btf = NULL;
- int err, type_id;
- struct btf *btf;
- __u32 nr_types;
+ struct btf *base_btf = NULL, *btf = NULL;
+ int err;

if (obj->base_btf_path) {
base_btf = btf__parse(obj->base_btf_path, NULL);
@@ -546,7 +543,7 @@ static int symbols_resolve(struct object *obj)
if (err) {
pr_err("FAILED: load base BTF from %s: %s\n",
obj->base_btf_path, strerror(-err));
- return -1;
+ goto out_err;
}
}

@@ -555,9 +552,30 @@ static int symbols_resolve(struct object *obj)
if (err) {
pr_err("FAILED: load BTF from %s: %s\n",
obj->btf_path ?: obj->path, strerror(-err));
- goto out;
+ goto out_err;
}

+ obj->base_btf = base_btf;
+ obj->btf = btf;
+
+ return 0;
+
+out_err:
+ btf__free(base_btf);
+ btf__free(btf);
+ return err;
+}
+
+static int symbols_resolve(struct object *obj)
+{
+ int nr_typedefs = obj->nr_typedefs;
+ int nr_structs = obj->nr_structs;
+ int nr_unions = obj->nr_unions;
+ int nr_funcs = obj->nr_funcs;
+ struct btf *btf = obj->btf;
+ int err, type_id;
+ __u32 nr_types;
+
err = -1;
nr_types = btf__type_cnt(btf);

@@ -615,8 +633,6 @@ static int symbols_resolve(struct object *obj)

err = 0;
out:
- btf__free(base_btf);
- btf__free(btf);
return err;
}

@@ -824,6 +840,9 @@ int main(int argc, const char **argv)
if (symbols_collect(&obj))
goto out;

+ if (load_btf(&obj))
+ goto out;
+
if (symbols_resolve(&obj))
goto out;

@@ -833,6 +852,8 @@ int main(int argc, const char **argv)
if (!(fatal_warnings && warnings))
err = 0;
out:
+ btf__free(obj.base_btf);
+ btf__free(obj.btf);
if (obj.efile.elf) {
elf_end(obj.efile.elf);
close(obj.efile.fd);
--
2.52.0