libbpf: Simplify BTF initialization logic (b7d7f3e1) · Commits · 戴 / test

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 <andriin@fb.com> Signed-off-by:

Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200117060801.1311525-3-andriin@fb.com

tools/lib/bpf/libbpf.c

+6 −13

Original line number	Diff line number	Diff line
		@@ -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;
		}

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