From patchwork Tue Aug 18 22:23:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 1347320 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=Y2iQsCWN; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BWQRK5hQlz9sPf for ; Wed, 19 Aug 2020 08:23:25 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726945AbgHRWXX (ORCPT ); Tue, 18 Aug 2020 18:23:23 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:11470 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726617AbgHRWXU (ORCPT ); Tue, 18 Aug 2020 18:23:20 -0400 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 07IMGeKM018046 for ; Tue, 18 Aug 2020 15:23:19 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=DIX4+I0+fka6sL2luSu5jA+zuSBAZrayhWkigZrpy0A=; b=Y2iQsCWNVJKOOWESKz2E9my53eV1+5a6dDFcdYcXC0AySG1p2n7lcRRhXqITVwfeFG/B HFXXAYdIGaWJL5+iPH9OK5d9mKDXqqGnnVUoYa9C/gzg6IBmWP8lk805C6I/fXp+vIa2 tNZ8vX0tkugVw9Xr3U8jSOkPlHFhXx1AQ0A= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 3304p3dbth-9 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 18 Aug 2020 15:23:19 -0700 Received: from intmgw003.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 18 Aug 2020 15:23:16 -0700 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id 2AC1037050C9; Tue, 18 Aug 2020 15:23:12 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Yonghong Song Smtp-Origin-Hostname: devbig003.ftw2.facebook.com To: , CC: Alexei Starovoitov , Daniel Borkmann , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf v2 3/3] bpftool: handle EAGAIN error code properly in pids collection Date: Tue, 18 Aug 2020 15:23:12 -0700 Message-ID: <20200818222312.2181675-1-yhs@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200818222309.2181236-1-yhs@fb.com> References: <20200818222309.2181236-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-08-18_16:2020-08-18,2020-08-18 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxlogscore=549 spamscore=0 mlxscore=0 clxscore=1015 suspectscore=8 adultscore=0 bulkscore=0 impostorscore=0 phishscore=0 priorityscore=1501 malwarescore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008180160 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When the error code is EAGAIN, the kernel signals the user space should retry the read() operation for bpf iterators. Let us do it. Signed-off-by: Yonghong Song Acked-by: Andrii Nakryiko --- tools/bpf/bpftool/pids.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c index e3b116325403..df7d8ec76036 100644 --- a/tools/bpf/bpftool/pids.c +++ b/tools/bpf/bpftool/pids.c @@ -134,6 +134,8 @@ int build_obj_refs_table(struct obj_refs_table *table, enum bpf_obj_type type) while (true) { ret = read(fd, buf, sizeof(buf)); if (ret < 0) { + if (errno == EAGAIN) + continue; err = -errno; p_err("failed to read PID iterator output: %d", err); goto out;