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=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 9B351C54FD0 for ; Mon, 27 Apr 2020 20:13:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DC662070B for ; Mon, 27 Apr 2020 20:13:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="KnHOEaT6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726877AbgD0UNF (ORCPT ); Mon, 27 Apr 2020 16:13:05 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:28250 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726845AbgD0UMy (ORCPT ); Mon, 27 Apr 2020 16:12:54 -0400 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 03RK1sOj011056 for ; Mon, 27 Apr 2020 13:12:52 -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=HqSdaGb829zK+zJhBFX9+xDvXanr5rLzppBntb0/dCo=; b=KnHOEaT6AYX1LbHTOc+cpfEyGkvlB4WxxUgkC2o9L3UrKBVsHnzftCyyOvo3VA9zL1yX 2MfxiFiDSLL30UbTCAXMDb5MFSaIVbWWjIkFAYCV7YGCT38zkA3dA0bclgREPmfGcLPg DUbK23YcibuJR88PQ6FqZq+UvcdDMm+t+RM= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 30mk1gdyeq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 27 Apr 2020 13:12:52 -0700 Received: from intmgw003.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::d) 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 13:12:51 -0700 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id C96BB3700871; Mon, 27 Apr 2020 13:12:47 -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 v1 11/19] bpf: add task and task/file targets Date: Mon, 27 Apr 2020 13:12:47 -0700 Message-ID: <20200427201247.2995622-1-yhs@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200427201235.2994549-1-yhs@fb.com> References: <20200427201235.2994549-1-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=2.50.10434:6.0.138,18.0.676 definitions=2020-04-27_15:2020-04-27,2020-04-27 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 impostorscore=0 suspectscore=0 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 mlxscore=0 malwarescore=0 bulkscore=0 spamscore=0 adultscore=0 clxscore=1015 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004270161 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Only the tasks belonging to "current" pid namespace are enumerated. For task/file target, the bpf program will have access to struct task_struct *task u32 fd struct file *file where fd/file is an open file for the task. Signed-off-by: Yonghong Song --- kernel/bpf/Makefile | 2 +- kernel/bpf/task_iter.c | 319 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 320 insertions(+), 1 deletion(-) create mode 100644 kernel/bpf/task_iter.c diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index b2b5eefc5254..37b2d8620153 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -2,7 +2,7 @@ obj-y :=3D core.o CFLAGS_core.o +=3D $(call cc-disable-warning, override-init) =20 -obj-$(CONFIG_BPF_SYSCALL) +=3D syscall.o verifier.o inode.o helpers.o tn= um.o bpf_iter.o map_iter.o +obj-$(CONFIG_BPF_SYSCALL) +=3D syscall.o verifier.o inode.o helpers.o tn= um.o bpf_iter.o map_iter.o task_iter.o obj-$(CONFIG_BPF_SYSCALL) +=3D hashtab.o arraymap.o percpu_freelist.o bp= f_lru_list.o lpm_trie.o map_in_map.o obj-$(CONFIG_BPF_SYSCALL) +=3D local_storage.o queue_stack_maps.o obj-$(CONFIG_BPF_SYSCALL) +=3D disasm.o diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c new file mode 100644 index 000000000000..ee29574e427d --- /dev/null +++ b/kernel/bpf/task_iter.c @@ -0,0 +1,319 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ + +#include +#include +#include +#include +#include +#include + +struct bpf_iter_seq_task_info { + struct pid_namespace *ns; + struct task_struct *task; + u32 id; +}; + +static struct task_struct *task_seq_get_next(struct pid_namespace *ns, u= 32 *id) +{ + struct task_struct *task =3D NULL; + struct pid *pid; + + rcu_read_lock(); + pid =3D idr_get_next(&ns->idr, id); + if (pid) + task =3D get_pid_task(pid, PIDTYPE_PID); + rcu_read_unlock(); + + return task; +} + +static void *task_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct bpf_iter_seq_task_info *info =3D seq->private; + struct task_struct *task; + u32 id =3D info->id; + + if (*pos =3D=3D 0) + info->ns =3D task_active_pid_ns(current); + + task =3D task_seq_get_next(info->ns, &id); + if (!task) + return NULL; + + ++*pos; + info->task =3D task; + info->id =3D id; + + return task; +} + +static void *task_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct bpf_iter_seq_task_info *info =3D seq->private; + struct task_struct *task; + + ++*pos; + ++info->id; + task =3D task_seq_get_next(info->ns, &info->id); + if (!task) + return NULL; + + put_task_struct(info->task); + info->task =3D task; + return task; +} + +struct bpf_iter__task { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct task_struct *, task); +}; + +int __init __bpf_iter__task(struct bpf_iter_meta *meta, struct task_stru= ct *task) +{ + return 0; +} + +static int task_seq_show(struct seq_file *seq, void *v) +{ + struct bpf_iter_meta meta; + struct bpf_iter__task ctx; + struct bpf_prog *prog; + int ret =3D 0; + + prog =3D bpf_iter_get_prog(seq, sizeof(struct bpf_iter_seq_task_info), + &meta.session_id, &meta.seq_num, + v =3D=3D (void *)0); + if (prog) { + meta.seq =3D seq; + ctx.meta =3D &meta; + ctx.task =3D v; + ret =3D bpf_iter_run_prog(prog, &ctx); + } + + return ret =3D=3D 0 ? 0 : -EINVAL; +} + +static void task_seq_stop(struct seq_file *seq, void *v) +{ + struct bpf_iter_seq_task_info *info =3D seq->private; + + if (!v) + task_seq_show(seq, v); + + if (info->task) { + put_task_struct(info->task); + info->task =3D NULL; + } +} + +static const struct seq_operations task_seq_ops =3D { + .start =3D task_seq_start, + .next =3D task_seq_next, + .stop =3D task_seq_stop, + .show =3D task_seq_show, +}; + +struct bpf_iter_seq_task_file_info { + struct pid_namespace *ns; + struct task_struct *task; + struct files_struct *files; + u32 id; + u32 fd; +}; + +static struct file *task_file_seq_get_next(struct pid_namespace *ns, u32= *id, + int *fd, struct task_struct **task, + struct files_struct **fstruct) +{ + struct files_struct *files; + struct task_struct *tk; + u32 sid =3D *id; + int sfd; + + /* If this function returns a non-NULL file object, + * it held a reference to the files_struct and file. + * Otherwise, it does not hold any reference. + */ +again: + if (*fstruct) { + files =3D *fstruct; + sfd =3D *fd; + } else { + tk =3D task_seq_get_next(ns, &sid); + if (!tk) + return NULL; + + files =3D get_files_struct(tk); + put_task_struct(tk); + if (!files) { + sid =3D ++(*id); + *fd =3D 0; + goto again; + } + *fstruct =3D files; + *task =3D tk; + if (sid =3D=3D *id) { + sfd =3D *fd; + } else { + *id =3D sid; + sfd =3D 0; + } + } + + rcu_read_lock(); + for (; sfd < files_fdtable(files)->max_fds; sfd++) { + struct file *f; + + f =3D fcheck_files(files, sfd); + if (!f) + continue; + *fd =3D sfd; + get_file(f); + rcu_read_unlock(); + return f; + } + + /* the current task is done, go to the next task */ + rcu_read_unlock(); + put_files_struct(files); + *fstruct =3D NULL; + sid =3D ++(*id); + *fd =3D 0; + goto again; +} + +static void *task_file_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct bpf_iter_seq_task_file_info *info =3D seq->private; + struct files_struct *files =3D NULL; + struct task_struct *task =3D NULL; + struct file *file; + u32 id =3D info->id; + int fd =3D info->fd; + + if (*pos =3D=3D 0) + info->ns =3D task_active_pid_ns(current); + + file =3D task_file_seq_get_next(info->ns, &id, &fd, &task, &files); + if (!file) { + info->files =3D NULL; + return NULL; + } + + ++*pos; + info->id =3D id; + info->fd =3D fd; + info->task =3D task; + info->files =3D files; + + return file; +} + +static void *task_file_seq_next(struct seq_file *seq, void *v, loff_t *p= os) +{ + struct bpf_iter_seq_task_file_info *info =3D seq->private; + struct files_struct *files =3D info->files; + struct task_struct *task =3D info->task; + struct file *file; + u32 id =3D info->id; + + ++*pos; + ++info->fd; + fput((struct file *)v); + file =3D task_file_seq_get_next(info->ns, &id, &info->fd, &task, &files= ); + if (!file) { + info->files =3D NULL; + return NULL; + } + + info->id =3D id; + info->task =3D task; + info->files =3D files; + + return file; +} + +struct bpf_iter__task_file { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct task_struct *, task); + u32 fd; + __bpf_md_ptr(struct file *, file); +}; + +int __init __bpf_iter__task_file(struct bpf_iter_meta *meta, + struct task_struct *task, u32 fd, + struct file *file) +{ + return 0; +} + +static int task_file_seq_show(struct seq_file *seq, void *v) +{ + struct bpf_iter_seq_task_file_info *info =3D seq->private; + struct bpf_iter__task_file ctx; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + int ret =3D 0; + + prog =3D bpf_iter_get_prog(seq, sizeof(struct bpf_iter_seq_task_file_in= fo), + &meta.session_id, &meta.seq_num, v =3D=3D (void *)0); + if (prog) { + meta.seq =3D seq; + ctx.meta =3D &meta; + ctx.task =3D info->task; + ctx.fd =3D info->fd; + ctx.file =3D v; + ret =3D bpf_iter_run_prog(prog, &ctx); + } + + return ret =3D=3D 0 ? 0 : -EINVAL; +} + +static void task_file_seq_stop(struct seq_file *seq, void *v) +{ + struct bpf_iter_seq_task_file_info *info =3D seq->private; + + if (v) + fput((struct file *)v); + else + task_file_seq_show(seq, v); + + if (info->files) { + put_files_struct(info->files); + info->files =3D NULL; + } +} + +static const struct seq_operations task_file_seq_ops =3D { + .start =3D task_file_seq_start, + .next =3D task_file_seq_next, + .stop =3D task_file_seq_stop, + .show =3D task_file_seq_show, +}; + +static int __init task_iter_init(void) +{ + struct bpf_iter_reg task_file_reg_info =3D { + .target =3D "task_file", + .target_func_name =3D "__bpf_iter__task_file", + .seq_ops =3D &task_file_seq_ops, + .seq_priv_size =3D sizeof(struct bpf_iter_seq_task_file_info), + .target_feature =3D 0, + }; + struct bpf_iter_reg task_reg_info =3D { + .target =3D "task", + .target_func_name =3D "__bpf_iter__task", + .seq_ops =3D &task_seq_ops, + .seq_priv_size =3D sizeof(struct bpf_iter_seq_task_info), + .target_feature =3D 0, + }; + int ret; + + ret =3D bpf_iter_reg_target(&task_reg_info); + if (ret) + return ret; + + return bpf_iter_reg_target(&task_file_reg_info); +} +late_initcall(task_iter_init); --=20 2.24.1