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 X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85AE7C43331 for ; Wed, 13 Nov 2019 03:15:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 528D4222BD for ; Wed, 13 Nov 2019 03:15:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="GNR5vsJN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726980AbfKMDPd (ORCPT ); Tue, 12 Nov 2019 22:15:33 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:62416 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726953AbfKMDPd (ORCPT ); Tue, 12 Nov 2019 22:15:33 -0500 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xAD38gOp007308 for ; Tue, 12 Nov 2019 19:15:32 -0800 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-type; s=facebook; bh=eQvAR0KsDAU7VVhlbgUlS3DZ+EoDvMFnLdJUpY5bPx0=; b=GNR5vsJNtT+A5sLHCrFCqy1hgGDNxWfUeADudP86sxaVC293FTeb74zmjM1jSTeEWZdG WEiiGEt8UfB5/Pu00JSH/kj25MDb2PXHP+dyQxdfub9moU4xXBpufLZP1J3VNV+RETRV eqlg7+zV2dhA0Akl+GFtWja9ILY9JvHFYqA= Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2w7pr2nu0k-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Tue, 12 Nov 2019 19:15:32 -0800 Received: from 2401:db00:12:9028:face:0:29:0 (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::127) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Tue, 12 Nov 2019 19:15:30 -0800 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id A57BD2EC1B1D; Tue, 12 Nov 2019 19:15:27 -0800 (PST) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v3 bpf-next 2/3] libbpf: make global data internal arrays mmap()-able, if possible Date: Tue, 12 Nov 2019 19:15:17 -0800 Message-ID: <20191113031518.155618-3-andriin@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191113031518.155618-1-andriin@fb.com> References: <20191113031518.155618-1-andriin@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-11-12_10:2019-11-11,2019-11-12 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 phishscore=0 suspectscore=8 clxscore=1015 adultscore=0 mlxlogscore=999 lowpriorityscore=0 malwarescore=0 spamscore=0 priorityscore=1501 mlxscore=0 bulkscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1911130026 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add detection of BPF_F_MMAPABLE flag support for arrays and add it as an extra flag to internal global data maps, if supported by kernel. This allows users to memory-map global data and use it without BPF map operations, greatly simplifying user experience. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 96ef18cfeffb..7e2be1288fa1 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -142,6 +142,8 @@ struct bpf_capabilities { __u32 btf_func:1; /* BTF_KIND_VAR and BTF_KIND_DATASEC support */ __u32 btf_datasec:1; + /* BPF_F_MMAPABLE is supported for arrays */ + __u32 array_mmap:1; }; /* @@ -856,8 +858,6 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, pr_warn("failed to alloc map name\n"); return -ENOMEM; } - pr_debug("map '%s' (global data): at sec_idx %d, offset %zu.\n", - map_name, map->sec_idx, map->sec_offset); def = &map->def; def->type = BPF_MAP_TYPE_ARRAY; @@ -865,6 +865,12 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, def->value_size = data->d_size; def->max_entries = 1; def->map_flags = type == LIBBPF_MAP_RODATA ? BPF_F_RDONLY_PROG : 0; + if (obj->caps.array_mmap) + def->map_flags |= BPF_F_MMAPABLE; + + pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n", + map_name, map->sec_idx, map->sec_offset, def->map_flags); + if (data_buff) { *data_buff = malloc(data->d_size); if (!*data_buff) { @@ -2160,6 +2166,27 @@ static int bpf_object__probe_btf_datasec(struct bpf_object *obj) return 0; } +static int bpf_object__probe_array_mmap(struct bpf_object *obj) +{ + struct bpf_create_map_attr attr = { + .map_type = BPF_MAP_TYPE_ARRAY, + .map_flags = BPF_F_MMAPABLE, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1, + }; + int fd; + + fd = bpf_create_map_xattr(&attr); + if (fd >= 0) { + obj->caps.array_mmap = 1; + close(fd); + return 1; + } + + return 0; +} + static int bpf_object__probe_caps(struct bpf_object *obj) { @@ -2168,6 +2195,7 @@ bpf_object__probe_caps(struct bpf_object *obj) bpf_object__probe_global_data, bpf_object__probe_btf_func, bpf_object__probe_btf_datasec, + bpf_object__probe_array_mmap, }; int i, ret; -- 2.17.1