From b7d7f3e185b6e643dcd49d1486b11cade8519008 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 16 Jan 2020 22:07:59 -0800 Subject: [PATCH] libbpf: Simplify BTF initialization logic 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 Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200117060801.1311525-3-andriin@fb.com --- 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; }