From patchwork Thu Feb 4 20:49:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 12068739 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=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 88BA1C433DB for ; Thu, 4 Feb 2021 20:51:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 394C864E24 for ; Thu, 4 Feb 2021 20:51:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229549AbhBDUuy (ORCPT ); Thu, 4 Feb 2021 15:50:54 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:12742 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229909AbhBDUuw (ORCPT ); Thu, 4 Feb 2021 15:50:52 -0500 Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 114KkRsr015925 for ; Thu, 4 Feb 2021 12:50:11 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=lXa7f3BdrIgby0kW++xbXBVSeOLBc2Pdxm/WmJbuD2k=; b=ERuynqQIdM4zDe4aUNCIt1HoL5ou5ble71iB+0UoBmo2VrHWen8OTdY3Vy+ZlYlfA7dQ TkAt/wuni1/mqXcmrHNpUPHvde+yqzGyLZgwkxmwXNXPa2vC6k7CTVFgk+TTEcGJN5Sl L3Y7qnKTLOGcflEufXH80/AY2scmi/q9lvI= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 36gfa1k8cr-8 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 04 Feb 2021 12:50:10 -0800 Received: from intmgw001.05.ash7.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Thu, 4 Feb 2021 12:50:08 -0800 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 10C2C62E1750; Thu, 4 Feb 2021 12:50:06 -0800 (PST) From: Song Liu To: , , CC: , , , , Song Liu Subject: [PATCH v4 bpf-next 0/4] introduce bpf_iter for task_vma Date: Thu, 4 Feb 2021 12:49:57 -0800 Message-ID: <20210204205002.4075937-1-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.737 definitions=2021-02-04_10:2021-02-04,2021-02-04 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 phishscore=0 impostorscore=0 mlxlogscore=760 priorityscore=1501 lowpriorityscore=0 clxscore=1015 mlxscore=0 suspectscore=0 bulkscore=0 adultscore=0 spamscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2102040128 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This set introduces bpf_iter for task_vma, which can be used to generate information similar to /proc/pid/maps. Patch 4/4 adds an example that mimics /proc/pid/maps. Current /proc//maps and /proc//smaps provide information of vma's of a process. However, these information are not flexible enough to cover all use cases. For example, if a vma cover mixed 2MB pages and 4kB pages (x86_64), there is no easy way to tell which address ranges are backed by 2MB pages. task_vma solves the problem by enabling the user to generate customize information based on the vma (and vma->vm_mm, vma->vm_file, etc.). Changes v3 => v4: 1. Avoid skipping vma by assigning invalid prev_vm_start in task_vma_seq_stop(). (Yonghong) 2. Move "again" label in task_vma_seq_get_next() save a check. (Yonghong) Changes v2 => v3: 1. Rewrite 1/4 so that we hold mmap_lock while calling BPF program. This enables the BPF program to access the real vma with BTF. (Alexei) 2. Fix the logic when the control is returned to user space. (Yonghong) 3. Revise commit log and cover letter. (Yonghong) Changes v1 => v2: 1. Small fixes in task_iter.c and the selftests. (Yonghong) Song Liu (4): bpf: introduce task_vma bpf_iter bpf: allow bpf_d_path in sleepable bpf_iter program libbpf: introduce section "iter.s/" for sleepable bpf_iter program selftests/bpf: add test for bpf_iter_task_vma kernel/bpf/task_iter.c | 215 +++++++++++++++++- kernel/trace/bpf_trace.c | 5 + tools/lib/bpf/libbpf.c | 5 + .../selftests/bpf/prog_tests/bpf_iter.c | 114 +++++++++- tools/testing/selftests/bpf/progs/bpf_iter.h | 8 + .../selftests/bpf/progs/bpf_iter_task_vma.c | 58 +++++ 6 files changed, 394 insertions(+), 11 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task_vma.c --- 2.24.1