If not fn_name, mod_len does never get initialized which fails now with gcc15 on Alpine Linux edge: libbpf.c: In function 'find_kernel_btf_id.constprop': libbpf.c:10100:33: error: 'mod_len' may be used uninitialized [-Werror=maybe-uninitialized] 10100 | if (mod_name && strncmp(mod->name, mod_name, mod_len) != 0) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ libbpf.c:10070:21: note: 'mod_len' was declared here 10070 | int ret, i, mod_len; | ^~~~~~~ Signed-off-by: Achill Gilgenast <fossdd@xxxxxxxxxx> Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx> Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx> Link: https://lore.kernel.org/bpf/20250729094611.2065713-1-fossdd@xxxxxxxxxx/ --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e067cb5776bd..fb4d92c5c339 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10086,27 +10086,27 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd, int t btf__free(btf); if (err <= 0) { pr_warn("%s is not found in prog's BTF\n", name); goto out; } out: return err; } static int find_kernel_btf_id(struct bpf_object *obj, const char *attach_name, enum bpf_attach_type attach_type, int *btf_obj_fd, int *btf_type_id) { - int ret, i, mod_len; + int ret, i, mod_len = 0; const char *fn_name, *mod_name = NULL; fn_name = strchr(attach_name, ':'); if (fn_name) { mod_name = attach_name; mod_len = fn_name - mod_name; fn_name++; } if (!mod_name || strncmp(mod_name, "vmlinux", mod_len) == 0) { ret = find_attach_btf_id(obj->btf_vmlinux, mod_name ? fn_name : attach_name, attach_type); -- 2.50.1
