From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanislav Fomichev Subject: [PATCH bpf-next v2 1/2] bpf: libbpf: retry program creation without the name Date: Tue, 20 Nov 2018 15:15:09 -0800 Message-ID: <20181120231510.46332-1-sdf@google.com> References: <20181120230445.os6ikxaqhq777xao@ast-mbp.dhcp.thefacebook.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: daniel@iogearbox.net, Stanislav Fomichev To: netdev@vger.kernel.org, ast@kernel.org Return-path: Received: from mail-ua1-f74.google.com ([209.85.222.74]:36901 "EHLO mail-ua1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725889AbeKUJqx (ORCPT ); Wed, 21 Nov 2018 04:46:53 -0500 Received: by mail-ua1-f74.google.com with SMTP id k15so787991uaq.4 for ; Tue, 20 Nov 2018 15:15:14 -0800 (PST) In-Reply-To: <20181120230445.os6ikxaqhq777xao@ast-mbp.dhcp.thefacebook.com> Sender: netdev-owner@vger.kernel.org List-ID: [Recent commit 23499442c319 ("bpf: libbpf: retry map creation without the name") fixed this issue for maps, let's do the same for programs.] Since commit 88cda1c9da02 ("bpf: libbpf: Provide basic API support to specify BPF obj name"), libbpf unconditionally sets bpf_attr->name for programs. Pre v4.14 kernels don't know about programs names and return an error about unexpected non-zero data. Retry bpf_load_program_xattr without a program name to cover older kernels. Signed-off-by: Stanislav Fomichev --- tools/lib/bpf/libbpf.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index cb6565d79603..2ea14dfa28fc 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1401,6 +1401,18 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, ret = bpf_load_program_xattr(&load_attr, log_buf, BPF_LOG_BUF_SIZE); + if (ret < 0 && errno == E2BIG && load_attr.name) { + /* Retry the same operation, but without the name. + * Pre v4.14 kernels don't support prog names. + */ + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); + pr_warning("Error in bpf_load_program_xattr(%s):%s(%d). Retrying without name.\n", + prog->name, cp, errno); + load_attr.name = NULL; + ret = bpf_load_program_xattr(&load_attr, log_buf, + BPF_LOG_BUF_SIZE); + } + if (ret >= 0) { *pfd = ret; ret = 0; -- 2.19.1.1215.g8438c0b245-goog