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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 03E74C4338F for ; Sun, 15 Aug 2021 07:07:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E206761038 for ; Sun, 15 Aug 2021 07:07:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236026AbhHOHHi convert rfc822-to-8bit (ORCPT ); Sun, 15 Aug 2021 03:07:38 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:42526 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235457AbhHOHHU (ORCPT ); Sun, 15 Aug 2021 03:07:20 -0400 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 17F75B3U014360 for ; Sun, 15 Aug 2021 00:06:48 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 3ae9vqc1we-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Sun, 15 Aug 2021 00:06:48 -0700 Received: from intmgw006.03.ash8.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Sun, 15 Aug 2021 00:06:47 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 2EA963D405A0; Sun, 15 Aug 2021 00:06:39 -0700 (PDT) From: Andrii Nakryiko To: , , CC: , , Peter Zijlstra Subject: [PATCH v5 bpf-next 14/16] selftests/bpf: add bpf_cookie selftests for high-level APIs Date: Sun, 15 Aug 2021 00:06:07 -0700 Message-ID: <20210815070609.987780-15-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210815070609.987780-1-andrii@kernel.org> References: <20210815070609.987780-1-andrii@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-FB-Source: Intern X-Proofpoint-GUID: JB8lw8jd6c_7bjyYyaz38Ef-W4-phJHN X-Proofpoint-ORIG-GUID: JB8lw8jd6c_7bjyYyaz38Ef-W4-phJHN X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-08-15_02:2021-08-13,2021-08-15 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 mlxscore=0 clxscore=1015 priorityscore=1501 lowpriorityscore=0 phishscore=0 bulkscore=0 suspectscore=0 impostorscore=0 mlxlogscore=999 spamscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108150049 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add selftest with few subtests testing proper bpf_cookie usage. Kprobe and uprobe subtests are pretty straightforward and just validate that the same BPF program attached with different bpf_cookie will be triggered with those different bpf_cookie values. Tracepoint subtest is a bit more interesting, as it is the only perf_event-based BPF hook that shares bpf_prog_array between multiple perf_events internally. This means that the same BPF program can't be attached to the same tracepoint multiple times. So we have 3 identical copies. This arrangement allows to test bpf_prog_array_copy()'s handling of bpf_prog_array list manipulation logic when programs are attached and detached. The test validates that bpf_cookie isn't mixed up and isn't lost during such list manipulations. Perf_event subtest validates that two BPF links can be created against the same perf_event (but not at the same time, only one BPF program can be attached to perf_event itself), and that for each we can specify different bpf_cookie value. Signed-off-by: Andrii Nakryiko --- .../selftests/bpf/prog_tests/bpf_cookie.c | 254 ++++++++++++++++++ .../selftests/bpf/progs/test_bpf_cookie.c | 85 ++++++ 2 files changed, 339 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/bpf_cookie.c create mode 100644 tools/testing/selftests/bpf/progs/test_bpf_cookie.c diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c new file mode 100644 index 000000000000..5eea3c3a40fe --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c @@ -0,0 +1,254 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include "test_bpf_cookie.skel.h" + +static void kprobe_subtest(struct test_bpf_cookie *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts); + struct bpf_link *link1 = NULL, *link2 = NULL; + struct bpf_link *retlink1 = NULL, *retlink2 = NULL; + + /* attach two kprobes */ + opts.bpf_cookie = 0x1; + opts.retprobe = false; + link1 = bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe, + SYS_NANOSLEEP_KPROBE_NAME, &opts); + if (!ASSERT_OK_PTR(link1, "link1")) + goto cleanup; + + opts.bpf_cookie = 0x2; + opts.retprobe = false; + link2 = bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe, + SYS_NANOSLEEP_KPROBE_NAME, &opts); + if (!ASSERT_OK_PTR(link2, "link2")) + goto cleanup; + + /* attach two kretprobes */ + opts.bpf_cookie = 0x10; + opts.retprobe = true; + retlink1 = bpf_program__attach_kprobe_opts(skel->progs.handle_kretprobe, + SYS_NANOSLEEP_KPROBE_NAME, &opts); + if (!ASSERT_OK_PTR(retlink1, "retlink1")) + goto cleanup; + + opts.bpf_cookie = 0x20; + opts.retprobe = true; + retlink2 = bpf_program__attach_kprobe_opts(skel->progs.handle_kretprobe, + SYS_NANOSLEEP_KPROBE_NAME, &opts); + if (!ASSERT_OK_PTR(retlink2, "retlink2")) + goto cleanup; + + /* trigger kprobe && kretprobe */ + usleep(1); + + ASSERT_EQ(skel->bss->kprobe_res, 0x1 | 0x2, "kprobe_res"); + ASSERT_EQ(skel->bss->kretprobe_res, 0x10 | 0x20, "kretprobe_res"); + +cleanup: + bpf_link__destroy(link1); + bpf_link__destroy(link2); + bpf_link__destroy(retlink1); + bpf_link__destroy(retlink2); +} + +static void uprobe_subtest(struct test_bpf_cookie *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts); + struct bpf_link *link1 = NULL, *link2 = NULL; + struct bpf_link *retlink1 = NULL, *retlink2 = NULL; + size_t uprobe_offset; + ssize_t base_addr; + + base_addr = get_base_addr(); + uprobe_offset = get_uprobe_offset(&get_base_addr, base_addr); + + /* attach two uprobes */ + opts.bpf_cookie = 0x100; + opts.retprobe = false; + link1 = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, 0 /* self pid */, + "/proc/self/exe", uprobe_offset, &opts); + if (!ASSERT_OK_PTR(link1, "link1")) + goto cleanup; + + opts.bpf_cookie = 0x200; + opts.retprobe = false; + link2 = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, -1 /* any pid */, + "/proc/self/exe", uprobe_offset, &opts); + if (!ASSERT_OK_PTR(link2, "link2")) + goto cleanup; + + /* attach two uretprobes */ + opts.bpf_cookie = 0x1000; + opts.retprobe = true; + retlink1 = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe, -1 /* any pid */, + "/proc/self/exe", uprobe_offset, &opts); + if (!ASSERT_OK_PTR(retlink1, "retlink1")) + goto cleanup; + + opts.bpf_cookie = 0x2000; + opts.retprobe = true; + retlink2 = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe, 0 /* self pid */, + "/proc/self/exe", uprobe_offset, &opts); + if (!ASSERT_OK_PTR(retlink2, "retlink2")) + goto cleanup; + + /* trigger uprobe && uretprobe */ + get_base_addr(); + + ASSERT_EQ(skel->bss->uprobe_res, 0x100 | 0x200, "uprobe_res"); + ASSERT_EQ(skel->bss->uretprobe_res, 0x1000 | 0x2000, "uretprobe_res"); + +cleanup: + bpf_link__destroy(link1); + bpf_link__destroy(link2); + bpf_link__destroy(retlink1); + bpf_link__destroy(retlink2); +} + +static void tp_subtest(struct test_bpf_cookie *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_tracepoint_opts, opts); + struct bpf_link *link1 = NULL, *link2 = NULL, *link3 = NULL; + + /* attach first tp prog */ + opts.bpf_cookie = 0x10000; + link1 = bpf_program__attach_tracepoint_opts(skel->progs.handle_tp1, + "syscalls", "sys_enter_nanosleep", &opts); + if (!ASSERT_OK_PTR(link1, "link1")) + goto cleanup; + + /* attach second tp prog */ + opts.bpf_cookie = 0x20000; + link2 = bpf_program__attach_tracepoint_opts(skel->progs.handle_tp2, + "syscalls", "sys_enter_nanosleep", &opts); + if (!ASSERT_OK_PTR(link2, "link2")) + goto cleanup; + + /* trigger tracepoints */ + usleep(1); + + ASSERT_EQ(skel->bss->tp_res, 0x10000 | 0x20000, "tp_res1"); + + /* now we detach first prog and will attach third one, which causes + * two internal calls to bpf_prog_array_copy(), shuffling + * bpf_prog_array_items around. We test here that we don't lose track + * of associated bpf_cookies. + */ + bpf_link__destroy(link1); + link1 = NULL; + kern_sync_rcu(); + skel->bss->tp_res = 0; + + /* attach third tp prog */ + opts.bpf_cookie = 0x40000; + link3 = bpf_program__attach_tracepoint_opts(skel->progs.handle_tp3, + "syscalls", "sys_enter_nanosleep", &opts); + if (!ASSERT_OK_PTR(link3, "link3")) + goto cleanup; + + /* trigger tracepoints */ + usleep(1); + + ASSERT_EQ(skel->bss->tp_res, 0x20000 | 0x40000, "tp_res2"); + +cleanup: + bpf_link__destroy(link1); + bpf_link__destroy(link2); + bpf_link__destroy(link3); +} + +static void burn_cpu(void) +{ + volatile int j = 0; + cpu_set_t cpu_set; + int i, err; + + /* generate some branches on cpu 0 */ + CPU_ZERO(&cpu_set); + CPU_SET(0, &cpu_set); + err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set); + ASSERT_OK(err, "set_thread_affinity"); + + /* spin the loop for a while (random high number) */ + for (i = 0; i < 1000000; ++i) + ++j; +} + +static void pe_subtest(struct test_bpf_cookie *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, opts); + struct bpf_link *link = NULL; + struct perf_event_attr attr; + int pfd = -1; + + /* create perf event */ + memset(&attr, 0, sizeof(attr)); + attr.size = sizeof(attr); + attr.type = PERF_TYPE_SOFTWARE; + attr.config = PERF_COUNT_SW_CPU_CLOCK; + attr.freq = 1; + attr.sample_freq = 4000; + pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); + if (!ASSERT_GE(pfd, 0, "perf_fd")) + goto cleanup; + + opts.bpf_cookie = 0x100000; + link = bpf_program__attach_perf_event_opts(skel->progs.handle_pe, pfd, &opts); + if (!ASSERT_OK_PTR(link, "link1")) + goto cleanup; + + burn_cpu(); /* trigger BPF prog */ + + ASSERT_EQ(skel->bss->pe_res, 0x100000, "pe_res1"); + + /* prevent bpf_link__destroy() closing pfd itself */ + bpf_link__disconnect(link); + /* close BPF link's FD explicitly */ + close(bpf_link__fd(link)); + /* free up memory used by struct bpf_link */ + bpf_link__destroy(link); + link = NULL; + kern_sync_rcu(); + skel->bss->pe_res = 0; + + opts.bpf_cookie = 0x200000; + link = bpf_program__attach_perf_event_opts(skel->progs.handle_pe, pfd, &opts); + if (!ASSERT_OK_PTR(link, "link2")) + goto cleanup; + + burn_cpu(); /* trigger BPF prog */ + + ASSERT_EQ(skel->bss->pe_res, 0x200000, "pe_res2"); + +cleanup: + close(pfd); + bpf_link__destroy(link); +} + +void test_bpf_cookie(void) +{ + struct test_bpf_cookie *skel; + + skel = test_bpf_cookie__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + skel->bss->my_tid = syscall(SYS_gettid); + + if (test__start_subtest("kprobe")) + kprobe_subtest(skel); + if (test__start_subtest("uprobe")) + uprobe_subtest(skel); + if (test__start_subtest("tracepoint")) + tp_subtest(skel); + if (test__start_subtest("perf_event")) + pe_subtest(skel); + + test_bpf_cookie__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_bpf_cookie.c b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c new file mode 100644 index 000000000000..2d3a7710e2ce --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include "vmlinux.h" +#include +#include + +int my_tid; + +int kprobe_res; +int kprobe_multi_res; +int kretprobe_res; +int uprobe_res; +int uretprobe_res; +int tp_res; +int pe_res; + +static void update(void *ctx, int *res) +{ + if (my_tid != (u32)bpf_get_current_pid_tgid()) + return; + + *res |= bpf_get_attach_cookie(ctx); +} + +SEC("kprobe/sys_nanosleep") +int handle_kprobe(struct pt_regs *ctx) +{ + update(ctx, &kprobe_res); + return 0; +} + +SEC("kretprobe/sys_nanosleep") +int handle_kretprobe(struct pt_regs *ctx) +{ + update(ctx, &kretprobe_res); + return 0; +} + +SEC("uprobe/trigger_func") +int handle_uprobe(struct pt_regs *ctx) +{ + update(ctx, &uprobe_res); + return 0; +} + +SEC("uretprobe/trigger_func") +int handle_uretprobe(struct pt_regs *ctx) +{ + update(ctx, &uretprobe_res); + return 0; +} + +/* bpf_prog_array, used by kernel internally to keep track of attached BPF + * programs to a given BPF hook (e.g., for tracepoints) doesn't allow the same + * BPF program to be attached multiple times. So have three identical copies + * ready to attach to the same tracepoint. + */ +SEC("tp/syscalls/sys_enter_nanosleep") +int handle_tp1(struct pt_regs *ctx) +{ + update(ctx, &tp_res); + return 0; +} +SEC("tp/syscalls/sys_enter_nanosleep") +int handle_tp2(struct pt_regs *ctx) +{ + update(ctx, &tp_res); + return 0; +} +SEC("tp/syscalls/sys_enter_nanosleep") +int handle_tp3(void *ctx) +{ + update(ctx, &tp_res); + return 1; +} + +SEC("perf_event") +int handle_pe(struct pt_regs *ctx) +{ + update(ctx, &pe_res); + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.30.2