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=-9.8 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,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 7FD4BC54E49 for ; Thu, 7 May 2020 05:40:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60F3A207DD for ; Thu, 7 May 2020 05:40:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="MhtiO8G2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726661AbgEGFk3 (ORCPT ); Thu, 7 May 2020 01:40:29 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:19582 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726134AbgEGFj0 (ORCPT ); Thu, 7 May 2020 01:39:26 -0400 Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0475YWYh006840 for ; Wed, 6 May 2020 22:39:25 -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=wuGOVWNZN+b7BwsJWWJzocwxX0Kb1JsXdXMhgR12GxQ=; b=MhtiO8G22CHGXV0iJc01+cVSofGyXIabxXZskjkseotPJnMn/AN1dqZex9I1ve6RDG3d IwdtK/k5YIxkl1F2l3YZbxS0owzayKiJbhQGcR5jC6Z3Ozt+lQOYQayeE8LIRrfzVTSe 7tmdy02q2TNEl2CuM5RIKY1dtg46SZdfFu8= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 30uxuxm2qv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 06 May 2020 22:39:25 -0700 Received: from intmgw002.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1847.3; Wed, 6 May 2020 22:39:24 -0700 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id 5BE1D3701B99; Wed, 6 May 2020 22:39:19 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Yonghong Song Smtp-Origin-Hostname: devbig003.ftw2.facebook.com To: Andrii Nakryiko , , Martin KaFai Lau , CC: Alexei Starovoitov , Daniel Borkmann , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next v3 04/21] bpf: support bpf tracing/iter programs for BPF_LINK_UPDATE Date: Wed, 6 May 2020 22:39:19 -0700 Message-ID: <20200507053919.1542666-1-yhs@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200507053915.1542140-1-yhs@fb.com> References: <20200507053915.1542140-1-yhs@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.676 definitions=2020-05-07_02:2020-05-05,2020-05-07 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 lowpriorityscore=0 adultscore=0 malwarescore=0 bulkscore=0 spamscore=0 clxscore=1015 impostorscore=0 priorityscore=1501 mlxlogscore=999 mlxscore=0 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005070043 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Added BPF_LINK_UPDATE support for tracing/iter programs. This way, a file based bpf iterator, which holds a reference to the link, can have its bpf program updated without creating new files. Acked-by: Andrii Nakryiko Signed-off-by: Yonghong Song --- kernel/bpf/bpf_iter.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 03f5832909db..0542a243b78c 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -23,6 +23,9 @@ struct bpf_iter_link { static struct list_head targets =3D LIST_HEAD_INIT(targets); static DEFINE_MUTEX(targets_mutex); =20 +/* protect bpf_iter_link changes */ +static DEFINE_MUTEX(link_mutex); + int bpf_iter_reg_target(struct bpf_iter_reg *reg_info) { struct bpf_iter_target_info *tinfo; @@ -111,9 +114,37 @@ static void bpf_iter_link_dealloc(struct bpf_link *l= ink) kfree(iter_link); } =20 +static int bpf_iter_link_replace(struct bpf_link *link, + struct bpf_prog *new_prog, + struct bpf_prog *old_prog) +{ + int ret =3D 0; + + mutex_lock(&link_mutex); + if (old_prog && link->prog !=3D old_prog) { + ret =3D -EPERM; + goto out_unlock; + } + + if (link->prog->type !=3D new_prog->type || + link->prog->expected_attach_type !=3D new_prog->expected_attach_typ= e || + link->prog->aux->attach_btf_id !=3D new_prog->aux->attach_btf_id) { + ret =3D -EINVAL; + goto out_unlock; + } + + old_prog =3D xchg(&link->prog, new_prog); + bpf_prog_put(old_prog); + +out_unlock: + mutex_unlock(&link_mutex); + return ret; +} + static const struct bpf_link_ops bpf_iter_link_lops =3D { .release =3D bpf_iter_link_release, .dealloc =3D bpf_iter_link_dealloc, + .update_prog =3D bpf_iter_link_replace, }; =20 int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *pr= og) --=20 2.24.1