From patchwork Mon May 4 06:25:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 220008 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=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 7F0C9C47257 for ; Mon, 4 May 2020 06:26:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DB15206EB for ; Mon, 4 May 2020 06:26:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="Y7JrDcCF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727863AbgEDG0D (ORCPT ); Mon, 4 May 2020 02:26:03 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:33290 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727822AbgEDGZ6 (ORCPT ); Mon, 4 May 2020 02:25:58 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.42/8.16.0.42) with SMTP id 0446ORVO015653 for ; Sun, 3 May 2020 23:25:57 -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=yekViGAMl9ig5D/9YjXrMssEWo+VghpxRRZ4nA9+Xv8=; b=Y7JrDcCFYOyj7NB+ROOi++ZqtPS6jNpjMUay3N02ZH4tkUsMrI0q90GX7g9pA5xsgTwR 2D/K0cbtVJY7FXygwNjQtqHuKpKrSlMXl+Bd8V7xi5LLcDX2Yei4QiH7QMIOfoUNlajt KRHisN5k3RAb3IBiWCVuFaNawq9Nq10M3e4= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0089730.ppops.net with ESMTP id 30s4byf1p2-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Sun, 03 May 2020 23:25:56 -0700 Received: from intmgw001.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1847.3; Sun, 3 May 2020 23:25:56 -0700 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id C01C63702037; Sun, 3 May 2020 23:25:54 -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 v2 07/20] bpf: create file bpf iterator Date: Sun, 3 May 2020 23:25:54 -0700 Message-ID: <20200504062554.2047969-1-yhs@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200504062547.2047304-1-yhs@fb.com> References: <20200504062547.2047304-1-yhs@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=2020-05-04_02:2020-05-01,2020-05-04 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 bulkscore=0 adultscore=0 phishscore=0 priorityscore=1501 mlxscore=0 spamscore=0 malwarescore=0 suspectscore=0 mlxlogscore=945 clxscore=1015 impostorscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005040054 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org To produce a file bpf iterator, the fd must be corresponding to a link_fd assocciated with a trace/iter program. When the pinned file is opened, a seq_file will be generated. Signed-off-by: Yonghong Song --- include/linux/bpf.h | 2 ++ kernel/bpf/bpf_iter.c | 17 ++++++++++++++++- kernel/bpf/inode.c | 5 ++++- 3 files changed, 22 insertions(+), 2 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 9108d1a9b934..26daf85cba10 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1022,6 +1022,7 @@ static inline void bpf_enable_instrumentation(void) extern const struct file_operations bpf_map_fops; extern const struct file_operations bpf_prog_fops; +extern const struct file_operations bpf_iter_fops; #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ extern const struct bpf_prog_ops _name ## _prog_ops; \ @@ -1144,6 +1145,7 @@ int bpf_iter_reg_target(struct bpf_iter_reg *reg_info); bool bpf_iter_prog_supported(struct bpf_prog *prog); int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); int bpf_iter_new_fd(struct bpf_link *link); +bool bpf_link_is_iter(struct bpf_link *link); int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value); int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value); diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 2a9f939be6e6..8bd787f3db6f 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -41,6 +41,8 @@ static DEFINE_MUTEX(link_mutex); /* incremented on every opened seq_file */ static atomic64_t session_id; +static int prepare_seq_file(struct file *file, struct bpf_iter_link *link); + /* bpf_seq_read, a customized and simpler version for bpf iterator. * no_llseek is assumed for this file. * The following are differences from seq_read(): @@ -169,6 +171,13 @@ static ssize_t bpf_seq_read(struct file *file, char __user *buf, size_t size, goto Done; } +static int iter_open(struct inode *inode, struct file *file) +{ + struct bpf_iter_link *link = inode->i_private; + + return prepare_seq_file(file, link); +} + static int iter_release(struct inode *inode, struct file *file) { struct bpf_iter_priv_data *iter_priv; @@ -188,7 +197,8 @@ static int iter_release(struct inode *inode, struct file *file) return seq_release_private(inode, file); } -static const struct file_operations bpf_iter_fops = { +const struct file_operations bpf_iter_fops = { + .open = iter_open, .llseek = no_llseek, .read = bpf_seq_read, .release = iter_release, @@ -290,6 +300,11 @@ static const struct bpf_link_ops bpf_iter_link_lops = { .update_prog = bpf_iter_link_replace, }; +bool bpf_link_is_iter(struct bpf_link *link) +{ + return link->ops == &bpf_iter_link_lops; +} + int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { struct bpf_link_primer link_primer; diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index 95087d9f4ed3..fb878ba3f22f 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -358,8 +358,11 @@ static int bpf_mkmap(struct dentry *dentry, umode_t mode, void *arg) static int bpf_mklink(struct dentry *dentry, umode_t mode, void *arg) { + struct bpf_link *link = arg; + return bpf_mkobj_ops(dentry, mode, arg, &bpf_link_iops, - &bpffs_obj_fops); + bpf_link_is_iter(link) ? + &bpf_iter_fops : &bpffs_obj_fops); } static struct dentry *