From patchwork Tue Sep 29 08:47:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 11805295 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 85856139A for ; Tue, 29 Sep 2020 08:48:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F32E207F7 for ; Tue, 29 Sep 2020 08:48:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="jWx7A5yx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727774AbgI2IsV (ORCPT ); Tue, 29 Sep 2020 04:48:21 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:42590 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725826AbgI2IsV (ORCPT ); Tue, 29 Sep 2020 04:48:21 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 08T8indt001277 for ; Tue, 29 Sep 2020 01:48:20 -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=+R97lXwFg5naeDERa3Nxp06DjosuYccCbTRkixjpzwk=; b=jWx7A5yxI7pwxL197DHpT1LA9P52/UERynmySILZ97gxEL9IUMfgIMTBk7R5jg7m5mOT kPrhaFOjFTyqTObtGHezJg3E7NjoDc1AbxMKX1h1YWWNlEHI7ddA7IZean46jVh3x9/a /8/jixYDlSB2OGR4c3cskgq1swA3pROcJVU= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 33tnwnsbmk-8 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 29 Sep 2020 01:48:20 -0700 Received: from intmgw003.08.frc2.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 29 Sep 2020 01:48:08 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 68DF962E5765; Tue, 29 Sep 2020 01:48:00 -0700 (PDT) From: Song Liu To: , CC: , , , , , Song Liu Subject: [PATCH bpf-next 1/2] bpf: introduce BPF_F_SHARE_PE for perf event array Date: Tue, 29 Sep 2020 01:47:49 -0700 Message-ID: <20200929084750.419168-2-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200929084750.419168-1-songliubraving@fb.com> References: <20200929084750.419168-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-29_01:2020-09-29,2020-09-29 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 phishscore=0 lowpriorityscore=0 mlxlogscore=999 impostorscore=0 bulkscore=0 adultscore=0 suspectscore=2 malwarescore=0 clxscore=1015 priorityscore=1501 mlxscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009290080 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Currently, perf event in perf event array is removed from the array when the map fd used to add the event is closed. This behavior makes it difficult to the share perf events with perf event array. Introduce perf event map that keeps the perf event open with a new flag BPF_F_SHARE_PE. With this flag set, perf events in the array are not removed when the original map fd is closed. Instead, the perf event will stay in the map until 1) it is explicitly removed from the array; or 2) the array is freed. Signed-off-by: Song Liu --- include/uapi/linux/bpf.h | 3 +++ kernel/bpf/arraymap.c | 31 +++++++++++++++++++++++++++++-- tools/include/uapi/linux/bpf.h | 3 +++ 3 files changed, 35 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 82522f05c0213..74f7a09e9d1e3 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -414,6 +414,9 @@ enum { /* Enable memory-mapping BPF map */ BPF_F_MMAPABLE = (1U << 10), + +/* Share perf_event among processes */ + BPF_F_SHARE_PE = (1U << 11), }; /* Flags for BPF_PROG_QUERY. */ diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index e5fd31268ae02..4938ff183d846 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -15,7 +15,7 @@ #include "map_in_map.h" #define ARRAY_CREATE_FLAG_MASK \ - (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK) + (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | BPF_F_SHARE_PE) static void bpf_array_free_percpu(struct bpf_array *array) { @@ -64,6 +64,10 @@ int array_map_alloc_check(union bpf_attr *attr) attr->map_flags & BPF_F_MMAPABLE) return -EINVAL; + if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY && + attr->map_flags & BPF_F_SHARE_PE) + return -EINVAL; + if (attr->value_size > KMALLOC_MAX_SIZE) /* if value_size is bigger, the user space won't be able to * access the elements. @@ -778,6 +782,26 @@ static int fd_array_map_delete_elem(struct bpf_map *map, void *key) } } +static void perf_event_fd_array_map_free(struct bpf_map *map) +{ + struct bpf_event_entry *ee; + struct bpf_array *array; + int i; + + if ((map->map_flags & BPF_F_SHARE_PE) == 0) { + fd_array_map_free(map); + return; + } + + array = container_of(map, struct bpf_array, map); + for (i = 0; i < array->map.max_entries; i++) { + ee = READ_ONCE(array->ptrs[i]); + if (ee) + fd_array_map_delete_elem(map, &i); + } + bpf_map_area_free(array); +} + static void *prog_fd_array_get_ptr(struct bpf_map *map, struct file *map_file, int fd) { @@ -1134,6 +1158,9 @@ static void perf_event_fd_array_release(struct bpf_map *map, struct bpf_event_entry *ee; int i; + if (map->map_flags & BPF_F_SHARE_PE) + return; + rcu_read_lock(); for (i = 0; i < array->map.max_entries; i++) { ee = READ_ONCE(array->ptrs[i]); @@ -1148,7 +1175,7 @@ const struct bpf_map_ops perf_event_array_map_ops = { .map_meta_equal = bpf_map_meta_equal, .map_alloc_check = fd_array_map_alloc_check, .map_alloc = array_map_alloc, - .map_free = fd_array_map_free, + .map_free = perf_event_fd_array_map_free, .map_get_next_key = array_map_get_next_key, .map_lookup_elem = fd_array_map_lookup_elem, .map_delete_elem = fd_array_map_delete_elem, diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 82522f05c0213..74f7a09e9d1e3 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -414,6 +414,9 @@ enum { /* Enable memory-mapping BPF map */ BPF_F_MMAPABLE = (1U << 10), + +/* Share perf_event among processes */ + BPF_F_SHARE_PE = (1U << 11), }; /* Flags for BPF_PROG_QUERY. */ From patchwork Tue Sep 29 08:47:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 11805293 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E2ACE139A for ; 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s=facebook; bh=f1DRt8DSh7xvwsbLwZtA/reljbesfZWQwqhLxzP0MJY=; b=iuH70HO4HlPxk8dd7EZ+wP1NRWtlHsW+aXTzKUjr99w2M9RnwVTKHGj2jAycU09EUsau MIv8SdtzeNHf82riPBxfN46hx5X0wWg6vU6zC6mwWrbl9p0Fj8zy6W1TKAUY2FMNLRiz /3PB7tuTtesLoAqU5AN839e5cjkNDCR/4cQ= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 33t3cpbv3w-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 29 Sep 2020 01:48:14 -0700 Received: from intmgw004.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::c) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 29 Sep 2020 01:48:13 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 165DB62E5765; Tue, 29 Sep 2020 01:48:06 -0700 (PDT) From: Song Liu To: , CC: , , , , , Song Liu Subject: [PATCH bpf-next 2/2] selftests/bpf: add tests for BPF_F_SHARE_PE Date: Tue, 29 Sep 2020 01:47:50 -0700 Message-ID: <20200929084750.419168-3-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200929084750.419168-1-songliubraving@fb.com> References: <20200929084750.419168-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-29_01:2020-09-29,2020-09-29 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 bulkscore=0 malwarescore=0 clxscore=1015 impostorscore=0 mlxlogscore=999 suspectscore=0 priorityscore=1501 lowpriorityscore=0 spamscore=0 adultscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009290080 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add tests for perf event array with and without BPF_F_SHARE_PE. Add a perf event to array via fd mfd. Without BPF_F_SHARE_PE, the perf event is removed when mfd is closed. With BPF_F_SHARE_PE, the perf event is removed when the map is freed. Signed-off-by: Song Liu --- .../bpf/prog_tests/perf_event_share.c | 68 +++++++++++++++++++ .../bpf/progs/test_perf_event_share.c | 44 ++++++++++++ 2 files changed, 112 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/perf_event_share.c create mode 100644 tools/testing/selftests/bpf/progs/test_perf_event_share.c diff --git a/tools/testing/selftests/bpf/prog_tests/perf_event_share.c b/tools/testing/selftests/bpf/prog_tests/perf_event_share.c new file mode 100644 index 0000000000000..a37cfdd047ea6 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/perf_event_share.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2019 Facebook */ +#include +#include +#include "test_perf_event_share.skel.h" + +static int duration; + +static void test_one_map(struct bpf_map *map, struct bpf_program *prog, + bool has_share_pe) +{ + int err, key = 0, pfd = -1, mfd = bpf_map__fd(map); + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts); + struct perf_event_attr attr = { + .size = sizeof(struct perf_event_attr), + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_CPU_CLOCK, + }; + + pfd = syscall(__NR_perf_event_open, &attr, 0 /* pid */, + -1 /* cpu 0 */, -1 /* group id */, 0 /* flags */); + if (CHECK(pfd < 0, "perf_event_open", "failed\n")) + return; + + err = bpf_map_update_elem(mfd, &key, &pfd, BPF_ANY); + if (CHECK(err < 0, "bpf_map_update_elem", "failed\n")) + goto cleanup; + + err = bpf_prog_test_run_opts(bpf_program__fd(prog), &opts); + if (CHECK(err < 0, "bpf_prog_test_run_opts", "failed\n")) + goto cleanup; + if (CHECK(opts.retval != 0, "bpf_perf_event_read_value", + "failed with %d\n", opts.retval)) + goto cleanup; + + /* closing mfd, prog still holds a reference on map */ + close(mfd); + + err = bpf_prog_test_run_opts(bpf_program__fd(prog), &opts); + if (CHECK(err < 0, "bpf_prog_test_run_opts", "failed\n")) + goto cleanup; + + if (has_share_pe) { + CHECK(opts.retval != 0, "bpf_perf_event_read_value", + "failed with %d\n", opts.retval); + } else { + CHECK(opts.retval != -ENOENT, "bpf_perf_event_read_value", + "should have failed with %d, but got %d\n", -ENOENT, + opts.retval); + } + +cleanup: + close(pfd); +} + +void test_perf_event_share(void) +{ + struct test_perf_event_share *skel; + + skel = test_perf_event_share__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + return; + + test_one_map(skel->maps.array_1, skel->progs.read_array_1, false); + test_one_map(skel->maps.array_2, skel->progs.read_array_2, true); + + test_perf_event_share__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_perf_event_share.c b/tools/testing/selftests/bpf/progs/test_perf_event_share.c new file mode 100644 index 0000000000000..005bfe375352f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_perf_event_share.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook +#include "vmlinux.h" +#include +#include + +struct { + __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); + __uint(max_entries, 1); + __uint(key_size, sizeof(int)); + __uint(value_size, sizeof(int)); +} array_1 SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); + __uint(max_entries, 1); + __uint(key_size, sizeof(int)); + __uint(value_size, sizeof(int)); + __uint(map_flags, BPF_F_SHARE_PE); /* array_2 has BPF_F_SHARE_PE */ +} array_2 SEC(".maps"); + +SEC("raw_tp/sched_switch") +int BPF_PROG(read_array_1) +{ + struct bpf_perf_event_value val; + long ret; + + ret = bpf_perf_event_read_value(&array_1, 0, &val, sizeof(val)); + bpf_printk("read_array_1 returns %ld", ret); + return ret; +} + +SEC("raw_tp/task_rename") +int BPF_PROG(read_array_2) +{ + struct bpf_perf_event_value val; + long ret; + + ret = bpf_perf_event_read_value(&array_2, 0, &val, sizeof(val)); + bpf_printk("read_array_2 returns %ld", ret); + return ret; +} + +char LICENSE[] SEC("license") = "GPL";