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 BFD72C64EC4 for ; Fri, 10 Mar 2023 04:39:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229521AbjCJEjh (ORCPT ); Thu, 9 Mar 2023 23:39:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229614AbjCJEjf (ORCPT ); Thu, 9 Mar 2023 23:39:35 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6375BFCF19 for ; Thu, 9 Mar 2023 20:39:34 -0800 (PST) Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 32A04CDP014226 for ; Thu, 9 Mar 2023 20:39:34 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=meta.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=s2048-2021-q4; bh=QycvHnbgwUnbcrYZODcnV5jg7n0J31oe6EYS4gId2cU=; b=JxJtK8GfeOpKI7+E2D77AokazPQ44zWWpxrFnWLe4SdEGlNNMnk1djR3l1Ddk366LevV dHLKvet2S4m05XmHcQAah8ElHo0iIPoReuSE3C6hdZ0fiGa0HwC9+9anS77oK/Ik5yw6 UOU5Z6pBgyvc3TbMr8QuDv0MiMOtRpx1LmnH94kljBv180MaG2yxARRUvq/SLYOIKRS1 5KH8VRjSBgDIWPxy3WpfFW4gcc+nJRw6Crjby+oqkyHp2XLNzcKYCQ8WJSxFNDI5YnT2 6F3zc0/6SqA8MAVLlDK37kl8Er88sY+cYkjidubT8f8ipWcreaqnky6B+mW3EKZoEr/d 4A== Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3p7sp5992u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 09 Mar 2023 20:39:34 -0800 Received: from twshared19568.39.frc1.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.17; Thu, 9 Mar 2023 20:39:33 -0800 Received: by devbig931.frc1.facebook.com (Postfix, from userid 460691) id DBDC96F6C2CE; Thu, 9 Mar 2023 20:39:25 -0800 (PST) From: Kui-Feng Lee To: , , , , , , CC: Kui-Feng Lee Subject: [PATCH bpf-next v6 6/8] libbpf: Update a bpf_link with another struct_ops. Date: Thu, 9 Mar 2023 20:38:11 -0800 Message-ID: <20230310043812.3087672-7-kuifeng@meta.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230310043812.3087672-1-kuifeng@meta.com> References: <20230310043812.3087672-1-kuifeng@meta.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: cxwJMemtx7U3FaOrzNBJLX-Z5uOYL_Q4 X-Proofpoint-GUID: cxwJMemtx7U3FaOrzNBJLX-Z5uOYL_Q4 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-10_01,2023-03-09_01,2023-02-09_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Introduce bpf_link__update_map(), which allows to atomically update underlying struct_ops implementation for given struct_ops BPF link Signed-off-by: Kui-Feng Lee --- tools/lib/bpf/libbpf.c | 30 ++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf.map | 1 + 3 files changed, 32 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6dbae7ffab48..63ec1f8fe8a0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -11659,6 +11659,36 @@ struct bpf_link *bpf_map__attach_struct_ops(cons= t struct bpf_map *map) return &link->link; } =20 +/* + * Swap the back struct_ops of a link with a new struct_ops map. + */ +int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *ma= p) +{ + struct bpf_link_struct_ops *st_ops_link; + __u32 zero =3D 0; + int err, fd; + + if (!bpf_map__is_struct_ops(map) || map->fd < 0) + return -EINVAL; + + st_ops_link =3D container_of(link, struct bpf_link_struct_ops, link); + /* Ensure the type of a link is correct */ + if (st_ops_link->map_fd < 0) + return -EINVAL; + + err =3D bpf_map_update_elem(map->fd, &zero, map->st_ops->kern_vdata, 0)= ; + if (err && err !=3D -EBUSY) + return err; + + fd =3D bpf_link_update(link->fd, map->fd, NULL); + if (fd < 0) + return fd; + + st_ops_link->map_fd =3D map->fd; + + return 0; +} + typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(struct perf_ev= ent_header *hdr, void *private_data); =20 diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index db4992a036f8..1615e55e2e79 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -719,6 +719,7 @@ bpf_program__attach_freplace(const struct bpf_program= *prog, struct bpf_map; =20 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_= map *map); +LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct = bpf_map *map); =20 struct bpf_iter_attach_opts { size_t sz; /* size of this struct for forward/backward compatibility */ diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 50dde1f6521e..cc05be376257 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -387,6 +387,7 @@ LIBBPF_1.2.0 { global: bpf_btf_get_info_by_fd; bpf_link_get_info_by_fd; + bpf_link__update_map; bpf_map_get_info_by_fd; bpf_prog_get_info_by_fd; } LIBBPF_1.1.0; --=20 2.34.1