From patchwork Tue Apr 28 05:49:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 220407 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, 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 87A48C83004 for ; Tue, 28 Apr 2020 05:50:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61AB2206A5 for ; Tue, 28 Apr 2020 05:50:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="QAUg5sta" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726401AbgD1Fub (ORCPT ); Tue, 28 Apr 2020 01:50:31 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:60956 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726329AbgD1Fub (ORCPT ); Tue, 28 Apr 2020 01:50:31 -0400 Received: from pps.filterd (m0148460.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 03S5oOP3005420 for ; Mon, 27 Apr 2020 22:50:30 -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=0XsjCOBMhNKDe5NDZMUP/D4zXoXfTqgtOkoHiqiV9QU=; b=QAUg5sta5rnH0zu1+kKkyzNZPiLUwy23LZe4sJSsiedQMeh6N9mFEEwVgaD57AX2QyDn zHHlZz/du/7vDWhbuPj24WqFxjLxhVfw+OzjJhriT678MzEzxEDTEAF8SdmjsmJAQ5yt ro1nc2o1VTmHa1tyC7H1rkz9fRrE3EsUvvo= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 30mjqn8spq-10 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 27 Apr 2020 22:50:29 -0700 Received: from intmgw003.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1847.3; Mon, 27 Apr 2020 22:49:53 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 8835D2EC3228; Mon, 27 Apr 2020 22:49:50 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v2 bpf-next 01/10] bpf: refactor bpf_link update handling Date: Mon, 27 Apr 2020 22:49:35 -0700 Message-ID: <20200428054944.4015462-2-andriin@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200428054944.4015462-1-andriin@fb.com> References: <20200428054944.4015462-1-andriin@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.676 definitions=2020-04-28_02:2020-04-27,2020-04-28 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 mlxscore=0 malwarescore=0 bulkscore=0 phishscore=0 clxscore=1015 mlxlogscore=914 spamscore=0 lowpriorityscore=0 impostorscore=0 suspectscore=8 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004280049 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Make bpf_link update support more generic by making it into another bpf_link_ops methods. This allows generic syscall handling code to be agnostic to various conditionally compiled features (e.g., the case of CONFIG_CGROUP_BPF). This also allows to keep link type-specific code to remain static within respective code base. Refactor existing bpf_cgroup_link code and take advantage of this. Signed-off-by: Andrii Nakryiko --- include/linux/bpf-cgroup.h | 12 ------------ include/linux/bpf.h | 3 ++- kernel/bpf/cgroup.c | 30 ++++++++++++++++++++++++++++-- kernel/bpf/syscall.c | 11 ++++------- kernel/cgroup/cgroup.c | 27 --------------------------- 5 files changed, 34 insertions(+), 49 deletions(-) diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index c11b413d5b1a..d2d969669564 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -100,8 +100,6 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, struct bpf_cgroup_link *link, enum bpf_attach_type type); -int __cgroup_bpf_replace(struct cgroup *cgrp, struct bpf_cgroup_link *link, - struct bpf_prog *new_prog); int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, union bpf_attr __user *uattr); @@ -112,8 +110,6 @@ int cgroup_bpf_attach(struct cgroup *cgrp, u32 flags); int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, enum bpf_attach_type type); -int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *old_prog, - struct bpf_prog *new_prog); int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, union bpf_attr __user *uattr); @@ -354,7 +350,6 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr, #else struct bpf_prog; -struct bpf_link; struct cgroup_bpf {}; static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; } static inline void cgroup_bpf_offline(struct cgroup *cgrp) {} @@ -378,13 +373,6 @@ static inline int cgroup_bpf_link_attach(const union bpf_attr *attr, return -EINVAL; } -static inline int cgroup_bpf_replace(struct bpf_link *link, - struct bpf_prog *old_prog, - struct bpf_prog *new_prog) -{ - return -EINVAL; -} - static inline int cgroup_bpf_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) { diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 10960cfabea4..81c8620cb4c4 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1093,7 +1093,8 @@ struct bpf_link { struct bpf_link_ops { void (*release)(struct bpf_link *link); void (*dealloc)(struct bpf_link *link); - + int (*update_prog)(struct bpf_link *link, struct bpf_prog *new_prog, + struct bpf_prog *old_prog); }; void bpf_link_init(struct bpf_link *link, const struct bpf_link_ops *ops, diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index fc7c7002fd37..0b284da05d0f 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -557,8 +557,9 @@ static void replace_effective_prog(struct cgroup *cgrp, * * Must be called with cgroup_mutex held. */ -int __cgroup_bpf_replace(struct cgroup *cgrp, struct bpf_cgroup_link *link, - struct bpf_prog *new_prog) +static int __cgroup_bpf_replace(struct cgroup *cgrp, + struct bpf_cgroup_link *link, + struct bpf_prog *new_prog) { struct list_head *progs = &cgrp->bpf.progs[link->type]; struct bpf_prog *old_prog; @@ -583,6 +584,30 @@ int __cgroup_bpf_replace(struct cgroup *cgrp, struct bpf_cgroup_link *link, return 0; } +static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog, + struct bpf_prog *old_prog) +{ + struct bpf_cgroup_link *cg_link; + int ret; + + cg_link = container_of(link, struct bpf_cgroup_link, link); + + mutex_lock(&cgroup_mutex); + /* link might have been auto-released by dying cgroup, so fail */ + if (!cg_link->cgroup) { + ret = -EINVAL; + goto out_unlock; + } + if (old_prog && link->prog != old_prog) { + ret = -EPERM; + goto out_unlock; + } + ret = __cgroup_bpf_replace(cg_link->cgroup, cg_link, new_prog); +out_unlock: + mutex_unlock(&cgroup_mutex); + return ret; +} + static struct bpf_prog_list *find_detach_entry(struct list_head *progs, struct bpf_prog *prog, struct bpf_cgroup_link *link, @@ -811,6 +836,7 @@ static void bpf_cgroup_link_dealloc(struct bpf_link *link) const struct bpf_link_ops bpf_cgroup_link_lops = { .release = bpf_cgroup_link_release, .dealloc = bpf_cgroup_link_dealloc, + .update_prog = cgroup_bpf_replace, }; int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 7626b8024471..f5358e1462eb 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3645,13 +3645,10 @@ static int link_update(union bpf_attr *attr) goto out_put_progs; } -#ifdef CONFIG_CGROUP_BPF - if (link->ops == &bpf_cgroup_link_lops) { - ret = cgroup_bpf_replace(link, old_prog, new_prog); - goto out_put_progs; - } -#endif - ret = -EINVAL; + if (link->ops->update_prog) + ret = link->ops->update_prog(link, new_prog, old_prog); + else + ret = EINVAL; out_put_progs: if (old_prog) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 06b5ea9d899d..557a9b9d2244 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -6508,33 +6508,6 @@ int cgroup_bpf_attach(struct cgroup *cgrp, return ret; } -int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *old_prog, - struct bpf_prog *new_prog) -{ - struct bpf_cgroup_link *cg_link; - int ret; - - if (link->ops != &bpf_cgroup_link_lops) - return -EINVAL; - - cg_link = container_of(link, struct bpf_cgroup_link, link); - - mutex_lock(&cgroup_mutex); - /* link might have been auto-released by dying cgroup, so fail */ - if (!cg_link->cgroup) { - ret = -EINVAL; - goto out_unlock; - } - if (old_prog && link->prog != old_prog) { - ret = -EPERM; - goto out_unlock; - } - ret = __cgroup_bpf_replace(cg_link->cgroup, cg_link, new_prog); -out_unlock: - mutex_unlock(&cgroup_mutex); - return ret; -} - int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, enum bpf_attach_type type) {