[PATCH bpf-next 2/4] libbpf: simplify BTF initialization logic
From: Andrii Nakryiko <hidden>
Date: 2020-01-17 06:08:14
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Current implementation of bpf_object's BTF initialization is very convoluted and thus prone to errors. It doesn't have to be like that. This patch simplifies it significantly. This code also triggered static analysis issues over logically dead code due to redundant error checks. This simplification should fix that as well. Signed-off-by: Andrii Nakryiko <redacted> --- tools/lib/bpf/libbpf.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 3afaca9bce1d..3b0b88c3377d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c@@ -2297,16 +2297,18 @@ static int bpf_object__init_btf(struct bpf_object *obj, Elf_Data *btf_data, Elf_Data *btf_ext_data) { - bool btf_required = bpf_object__is_btf_mandatory(obj); - int err = 0; + int err = -ENOENT; if (btf_data) { obj->btf = btf__new(btf_data->d_buf, btf_data->d_size); if (IS_ERR(obj->btf)) { + err = PTR_ERR(obj->btf); + obj->btf = NULL; pr_warn("Error loading ELF section %s: %d.\n", BTF_ELF_SEC, err); goto out; } + err = 0; } if (btf_ext_data) { if (!obj->btf) {
@@ -2324,18 +2326,9 @@ static int bpf_object__init_btf(struct bpf_object *obj, } } out: - if (err || IS_ERR(obj->btf)) { - if (btf_required) - err = err ? : PTR_ERR(obj->btf); - else - err = 0; - if (!IS_ERR_OR_NULL(obj->btf)) - btf__free(obj->btf); - obj->btf = NULL; - } - if (btf_required && !obj->btf) { + if (err && bpf_object__is_btf_mandatory(obj)) { pr_warn("BTF is required, but is missing or corrupted.\n"); - return err == 0 ? -ENOENT : err; + return err; } return 0; }
--
2.17.1