From patchwork Mon Sep 12 10:11:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Marchevsky X-Patchwork-Id: 12973539 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4446EECAAD5 for ; Mon, 12 Sep 2022 10:11:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229569AbiILKLT (ORCPT ); Mon, 12 Sep 2022 06:11:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229498AbiILKLT (ORCPT ); Mon, 12 Sep 2022 06:11:19 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E71511D0E2 for ; Mon, 12 Sep 2022 03:11:17 -0700 (PDT) Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28C3RxiE004812 for ; Mon, 12 Sep 2022 03:11:17 -0700 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=GrI7o9/3/ri+nmbxzBpOB+4deChuDQZ8KLaqT3tZW5U=; b=HR65RM3hZ6GPgowYA94UJTK6IDmphIQuNfuVuToPu5oQtzWCll9/Ac3vZ/80nocMzO2N XFoyK6rFj0E5L+EJU5CrLrwdD8aFNDt3Mk7p1S684iFdwg7qXLOWDQiPGOlyMrqlwE/+ Kt3qbIdDgiyHMEMkvW8du0ii5GNCy15SV8o= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3jgsw48asy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 12 Sep 2022 03:11:17 -0700 Received: from twshared1781.23.frc3.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 15.1.2375.31; Mon, 12 Sep 2022 03:11:16 -0700 Received: by devbig077.ldc1.facebook.com (Postfix, from userid 158236) id BD3E9D59737A; Mon, 12 Sep 2022 03:11:08 -0700 (PDT) From: Dave Marchevsky To: CC: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Kernel Team , Liam Wisehart , Dave Marchevsky Subject: [PATCH bpf-next 1/2] bpf: Allow ringbuf memory to be used as map key Date: Mon, 12 Sep 2022 03:11:05 -0700 Message-ID: <20220912101106.2765921-1-davemarchevsky@fb.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: KW7PPUN8Gl0N2vX9ZIHgHcZRcKqA-_6Y X-Proofpoint-GUID: KW7PPUN8Gl0N2vX9ZIHgHcZRcKqA-_6Y X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-12_06,2022-09-12_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This patch adds support for the following pattern: struct some_data *data = bpf_ringbuf_reserve(&ringbuf, sizeof(struct some_data, 0)); bpf_map_lookup_elem(&another_map, &data->some_field); bpf_ringbuf_submit(data); Currently the verifier does not consider bpf_ringbuf_reserve's PTR_TO_MEM ret type a valid key input to bpf_map_lookup_elem. Since PTR_TO_MEM is by definition a valid region of memory, it is safe to use it as a key for lookups. Signed-off-by: Dave Marchevsky --- kernel/bpf/verifier.c | 2 + tools/testing/selftests/bpf/Makefile | 8 ++- .../selftests/bpf/prog_tests/ringbuf.c | 10 +++ .../bpf/progs/test_ringbuf_map_key.c | 69 +++++++++++++++++++ 4 files changed, 86 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index c259d734f863..d093618aed99 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5626,6 +5626,8 @@ static const struct bpf_reg_types map_key_value_types = { PTR_TO_PACKET_META, PTR_TO_MAP_KEY, PTR_TO_MAP_VALUE, + PTR_TO_MEM, + PTR_TO_MEM | MEM_ALLOC, }, }; diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 6cd327f1f216..231d9c1364c9 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -351,9 +351,11 @@ LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h \ test_subskeleton.skel.h test_subskeleton_lib.skel.h \ test_usdt.skel.h -LSKELS := fentry_test.c fexit_test.c fexit_sleep.c \ - test_ringbuf.c atomics.c trace_printk.c trace_vprintk.c \ - map_ptr_kern.c core_kern.c core_kern_overflow.c +LSKELS := fentry_test.c fexit_test.c fexit_sleep.c atomics.c \ + trace_printk.c trace_vprintk.c map_ptr_kern.c \ + core_kern.c core_kern_overflow.c test_ringbuf.c \ + test_ringbuf_map_key.c + # Generate both light skeleton and libbpf skeleton for these LSKELS_EXTRA := test_ksyms_module.c test_ksyms_weak.c kfunc_call_test.c \ kfunc_call_test_subprog.c diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testing/selftests/bpf/prog_tests/ringbuf.c index 9a80fe8a6427..1cf458d1a179 100644 --- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c @@ -13,6 +13,7 @@ #include #include #include "test_ringbuf.lskel.h" +#include "test_ringbuf_map_key.lskel.h" #define EDONE 7777 @@ -297,3 +298,12 @@ void test_ringbuf(void) ring_buffer__free(ringbuf); test_ringbuf_lskel__destroy(skel); } + +void test_ringbuf_map_key(void) +{ + struct test_ringbuf_map_key_lskel *skel_map_key; + + skel_map_key = test_ringbuf_map_key_lskel__open_and_load(); + ASSERT_OK_PTR(skel_map_key, "test_ringbuf_map_key_lskel__open_and_load failed"); + test_ringbuf_map_key_lskel__destroy(skel_map_key); +} diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c b/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c new file mode 100644 index 000000000000..96a791a9762e --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +struct sample { + int pid; + int seq; + long value; + char comm[16]; +}; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); + __uint(max_entries, 4096); +} ringbuf SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 1000); + __type(key, struct sample); + __type(value, int); +} hash_map SEC(".maps"); + +/* inputs */ +int pid = 0; +long value = 0; +long flags = 0; + +/* outputs */ +long total = 0; +long dropped = 0; + +/* inner state */ +long seq = 0; + +SEC("fentry/" SYS_PREFIX "sys_getpgid") +int test_ringbuf_mem_map_key(void *ctx) +{ + int cur_pid = bpf_get_current_pid_tgid() >> 32; + struct sample *sample; + int *lookup_val; + int zero = 0; + + if (cur_pid != pid) + return 0; + + sample = bpf_ringbuf_reserve(&ringbuf, sizeof(*sample), 0); + if (!sample) { + __sync_fetch_and_add(&dropped, 1); + return 0; + } + + sample->pid = pid; + bpf_get_current_comm(sample->comm, sizeof(sample->comm)); + sample->value = value; + sample->seq = seq++; + + /* This prog is never run, successful load w/ below use of sample mem + * as map key is considered success + */ + lookup_val = (int *)bpf_map_lookup_elem(&hash_map, sample); + bpf_ringbuf_submit(sample, 0); + return 0; +}