libbpf: extract BTF loading logic

As a preparation for adding BTF-based BPF map loading, extract .BTF and
.BTF.ext loading logic.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e725fa86b189343385db16f432bf9d1500e3bea1..49d3a808e754ac9ae5d3b3b01f12198aa11c75c3 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1078,6 +1078,58 @@ static void bpf_object__sanitize_btf_ext(struct bpf_object *obj)
        }
 }
 
+static int bpf_object__load_btf(struct bpf_object *obj,
+                               Elf_Data *btf_data,
+                               Elf_Data *btf_ext_data)
+{
+       int err = 0;
+
+       if (btf_data) {
+               obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
+               if (IS_ERR(obj->btf)) {
+                       pr_warning("Error loading ELF section %s: %d.\n",
+                                  BTF_ELF_SEC, err);
+                       goto out;
+               }
+               err = btf__finalize_data(obj, obj->btf);
+               if (err) {
+                       pr_warning("Error finalizing %s: %d.\n",
+                                  BTF_ELF_SEC, err);
+                       goto out;
+               }
+               bpf_object__sanitize_btf(obj);
+               err = btf__load(obj->btf);
+               if (err) {
+                       pr_warning("Error loading %s into kernel: %d.\n",
+                                  BTF_ELF_SEC, err);
+                       goto out;
+               }
+       }
+       if (btf_ext_data) {
+               if (!obj->btf) {
+                       pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
+                                BTF_EXT_ELF_SEC, BTF_ELF_SEC);
+                       goto out;
+               }
+               obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
+                                           btf_ext_data->d_size);
+               if (IS_ERR(obj->btf_ext)) {
+                       pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
+                                  BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ext));
+                       obj->btf_ext = NULL;
+                       goto out;
+               }
+               bpf_object__sanitize_btf_ext(obj);
+       }
+out:
+       if (err || IS_ERR(obj->btf)) {
+               if (!IS_ERR_OR_NULL(obj->btf))
+                       btf__free(obj->btf);
+               obj->btf = NULL;
+       }
+       return 0;
+}
+
 static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 {
        Elf *elf = obj->efile.elf;
@@ -1212,44 +1264,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
                pr_warning("Corrupted ELF file: index of strtab invalid\n");
                return -LIBBPF_ERRNO__FORMAT;
        }
-       if (btf_data) {
-               obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
-               if (IS_ERR(obj->btf)) {
-                       pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
-                                  BTF_ELF_SEC, PTR_ERR(obj->btf));
-                       obj->btf = NULL;
-               } else {
-                       err = btf__finalize_data(obj, obj->btf);
-                       if (!err) {
-                               bpf_object__sanitize_btf(obj);
-                               err = btf__load(obj->btf);
-                       }
-                       if (err) {
-                               pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n",
-                                          BTF_ELF_SEC, err);
-                               btf__free(obj->btf);
-                               obj->btf = NULL;
-                               err = 0;
-                       }
-               }
-       }
-       if (btf_ext_data) {
-               if (!obj->btf) {
-                       pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
-                                BTF_EXT_ELF_SEC, BTF_ELF_SEC);
-               } else {
-                       obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
-                                                   btf_ext_data->d_size);
-                       if (IS_ERR(obj->btf_ext)) {
-                               pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
-                                          BTF_EXT_ELF_SEC,
-                                          PTR_ERR(obj->btf_ext));
-                               obj->btf_ext = NULL;
-                       } else {
-                               bpf_object__sanitize_btf_ext(obj);
-                       }
-               }
-       }
+       err = bpf_object__load_btf(obj, btf_data, btf_ext_data);
+       if (err)
+               return err;
        if (bpf_object__has_maps(obj)) {
                err = bpf_object__init_maps(obj, flags);
                if (err)