libbpf: Prevent loading vmlinux BTF twice (192b6638) · Commits · 戴 / test

tools/lib/bpf/libbpf.c

+22 −11

Original line number	Diff line number	Diff line
		@@ -2504,11 +2504,24 @@ static inline bool libbpf_prog_needs_vmlinux_btf(struct bpf_program *prog)

		static int bpf_object__load_vmlinux_btf(struct bpf_object *obj)
		{
		bool need_vmlinux_btf = false;
		struct bpf_program *prog;
		int err;

		/* CO-RE relocations need kernel BTF */
		if (obj->btf_ext && obj->btf_ext->field_reloc_info.len)
		need_vmlinux_btf = true;

		bpf_object__for_each_program(prog, obj) {
		if (libbpf_prog_needs_vmlinux_btf(prog)) {
		need_vmlinux_btf = true;
		break;
		}
		}

		if (!need_vmlinux_btf)
		return 0;

		obj->btf_vmlinux = libbpf_find_kernel_btf();
		if (IS_ERR(obj->btf_vmlinux)) {
		err = PTR_ERR(obj->btf_vmlinux);
		@@ -2518,10 +2531,6 @@ static int bpf_object__load_vmlinux_btf(struct bpf_object *obj)
		}
		return 0;
		}
		}

		return 0;
		}

		static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
		{
		@@ -4945,8 +4954,8 @@ bpf_core_reloc_fields(struct bpf_object obj, const char targ_btf_path)
		if (targ_btf_path)
		targ_btf = btf__parse_elf(targ_btf_path, NULL);
		else
		targ_btf = libbpf_find_kernel_btf();
		if (IS_ERR(targ_btf)) {
		targ_btf = obj->btf_vmlinux;
		if (IS_ERR_OR_NULL(targ_btf)) {
		pr_warn("failed to get target BTF: %ld\n", PTR_ERR(targ_btf));
		return PTR_ERR(targ_btf);
		}
		@@ -4987,6 +4996,8 @@ bpf_core_reloc_fields(struct bpf_object obj, const char targ_btf_path)
		}

		out:
		/* obj->btf_vmlinux is freed at the end of object load phase */
		if (targ_btf != obj->btf_vmlinux)
		btf__free(targ_btf);
		if (!IS_ERR_OR_NULL(cand_cache)) {
		hashmap__for_each_entry(cand_cache, entry, i) {