From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39A01C43334 for ; Thu, 2 Jun 2022 08:55:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232571AbiFBIza (ORCPT ); Thu, 2 Jun 2022 04:55:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232557AbiFBIz3 (ORCPT ); Thu, 2 Jun 2022 04:55:29 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8273929C107; Thu, 2 Jun 2022 01:55:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 14A8EB81EFC; Thu, 2 Jun 2022 08:55:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DBC5C385A5; Thu, 2 Jun 2022 08:55:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1654160125; bh=r78DM0Wp+cO4uP5J+DDcSdxZzpS4QO/M9XYiEnYZJd8=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=HkN82rYCiYxiTa4GlCFcPgghdGCvF1ItoParmyyYidK2QTEsvMOqiV653dpSAFbHD mxtGG2oH91TIGW/ZvbTKqUdU/LUbMc1AKpzkjpYurILBDLJeOLj8PxMzMvoKn2q/CI 2MR7w7DIzil6spbOIWPQs6PfC4z7EVSFpGUiQvFnsi+sIwEK8x34l4coGMGMHctmi2 ph0pMPK8h1+ZhjxAKz4j+Cq2hZO3dZzjup4ny297kAbryFuOhq90/LTCrkc4DeDYSW 5I+uh+ClobcJAG4Kvx9avtxOuYGhTfLw4JTbT0IK5mdYyoiWhp3VlvIsTTmvtQT/6S Cz3Wt5ziLfSxw== Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id C0E30405243; Thu, 2 Jun 2022 10:55:20 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Zhengchao Shao , bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net, kuba@kernel.org, hawk@kernel.org, john.fastabend@gmail.com, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, kpsingh@kernel.org Cc: weiyongjun1@huawei.com, shaozhengchao@huawei.com, yuehaibing@huawei.com Subject: Re: [PATCH v5,bpf-next] samples/bpf: check detach prog exist or not in xdp_fwd In-Reply-To: <20220602011915.264431-1-shaozhengchao@huawei.com> References: <20220602011915.264431-1-shaozhengchao@huawei.com> X-Clacks-Overhead: GNU Terry Pratchett Date: Thu, 02 Jun 2022 10:55:20 +0200 Message-ID: <87v8tjsavb.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Zhengchao Shao writes: > Before detach the prog, we should check detach prog exist or not. > > Signed-off-by: Zhengchao Shao You missed one 'return errno', see below: > --- > samples/bpf/xdp_fwd_user.c | 55 +++++++++++++++++++++++++++++++++----- > 1 file changed, 49 insertions(+), 6 deletions(-) > > diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c > index 1828487bae9a..d321e6aa9364 100644 > --- a/samples/bpf/xdp_fwd_user.c > +++ b/samples/bpf/xdp_fwd_user.c > @@ -47,17 +47,60 @@ static int do_attach(int idx, int prog_fd, int map_fd, const char *name) > return err; > } > > -static int do_detach(int idx, const char *name) > +static int do_detach(int ifindex, const char *ifname, const char *app_name) > { > - int err; > + LIBBPF_OPTS(bpf_xdp_attach_opts, opts); > + struct bpf_prog_info prog_info = {}; > + char prog_name[BPF_OBJ_NAME_LEN]; > + __u32 info_len, curr_prog_id; > + int prog_fd; > + int err = 1; > + > + if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) { > + printf("ERROR: bpf_xdp_query_id failed (%s)\n", > + strerror(errno)); > + return err; > + } > > - err = bpf_xdp_detach(idx, xdp_flags, NULL); > - if (err < 0) > - printf("ERROR: failed to detach program from %s\n", name); > + if (!curr_prog_id) { > + printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n", > + xdp_flags, ifname); > + return err; > + } > > + info_len = sizeof(prog_info); > + prog_fd = bpf_prog_get_fd_by_id(curr_prog_id); > + if (prog_fd < 0) { > + printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n", > + strerror(errno)); > + return errno; This should just be 'return prog_fd' to propagate the error... -Toke