From patchwork Tue Dec 20 22:01:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 13078200 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 EDE8AC4332F for ; Tue, 20 Dec 2022 22:02:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233946AbiLTWBz (ORCPT ); Tue, 20 Dec 2022 17:01:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234195AbiLTWBx (ORCPT ); Tue, 20 Dec 2022 17:01:53 -0500 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCD4A265B; Tue, 20 Dec 2022 14:01:51 -0800 (PST) Received: by mail-pj1-x1032.google.com with SMTP id o12so13802201pjo.4; Tue, 20 Dec 2022 14:01:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=Een9ADhaz5ehEAwvU7HmNyImJ88Ez5hMroHk5J56uIY=; b=SYMe3153Rgqa44SBJ483+8SEvUSJddnUW99SDn7Cb7pisiecKZ4W9gurVO9hgUr85U xWVIaidt/JbnlDs+ZA+sEB+RmzsUVxqHG5Bkxr5AczT73lAmR6y9BTa2QCambxcvjt9N ifU4qYhtoyoQYg6OgVNToRz7WshXgdBhqs0hDtHbQSY7ALJ1ViRQXukWfMO9uL/UxXIo izzbQ5JUfhgnciKx9aawh7HZsvmWErSipBZNEhxjWsgUVBuwSfnD92MEaqgap4ZbT0C+ PcjfLOUpLXVcUrDC9Oex6c4EGRq1ME2Mf5ftHlZD2gYc0lIrRepJJCpygbVjCj/4bwFr S47g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=Een9ADhaz5ehEAwvU7HmNyImJ88Ez5hMroHk5J56uIY=; b=uPNyJI62gC73Mfjb1wbL4epExfc6cgZbFAN/p8M7SSSckokukXPlIRCCG+H2jjPy3S PRhz+BU13NpG8DMBfys8nSJ0mdjcHJ+9CCTI9mGOsMbLtvBvVSYpnQ3FE/Fh3pEMrCUW 7A4GwW5NVlYwAD1VUXTr6bYiVHQt6QoFbaAf6/REJBfBtj8ET5EtVJYpPOM4Yzvwd7+t m8lEAAD8Wo6GPrrFsUE9zIWs4ZOGCa1bPnDgynYkhpKw13xHxuhFVeErU8app4GWjpJ/ JPYj4ugEwyrTutmwvJ07/99c8e2fn2p/ad3a4F+G6jYwHxccbbWQvIQMEMpC7IU/QKvw l9mA== X-Gm-Message-State: ANoB5pn8BknGcIcWXjU5eBhgJrLPZRzfQLarlACLLdSDcOrWbJGXBUEq DEt8YVgN7mFl1GGGsvclCUo= X-Google-Smtp-Source: AA0mqf54MeYpjZZW+1Y7x5xPCzVqiUZI5umLUtQO1SZfSgWrcvf7l7Y/KSS2ywRVk0CE1Z9PrRZJ3Q== X-Received: by 2002:a17:90a:db04:b0:219:b936:6bd7 with SMTP id g4-20020a17090adb0400b00219b9366bd7mr49496981pjv.19.1671573711192; Tue, 20 Dec 2022 14:01:51 -0800 (PST) Received: from youngsil.svl.corp.google.com ([2620:15c:2d4:203:68c4:de54:581a:ee2]) by smtp.gmail.com with ESMTPSA id 2-20020a17090a174200b00217090ece49sm14374pjm.31.2022.12.20.14.01.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Dec 2022 14:01:50 -0800 (PST) Sender: Namhyung Kim From: Namhyung Kim To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Song Liu , Jiri Olsa , Peter Zijlstra Cc: Martin KaFai Lau , Yonghong Song , John Fastabend , KP Singh , Hao Luo , Stanislav Fomichev , LKML , bpf@vger.kernel.org, Ingo Molnar , Arnaldo Carvalho de Melo Subject: [PATCH bpf-next 2/2] selftests/bpf: Add perf_event_read_sample test cases Date: Tue, 20 Dec 2022 14:01:44 -0800 Message-Id: <20221220220144.4016213-3-namhyung@kernel.org> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog In-Reply-To: <20221220220144.4016213-1-namhyung@kernel.org> References: <20221220220144.4016213-1-namhyung@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net It checks the perf event sample access with bpf_cast_to_kern_ctx(). It should access sample data only event->attr.sample_type allows. Other fields might not be initialized. $ ./vmtest.sh ./test_progs -t perf_event_read_sample ... #135/1 perf_event_read_sample/perf_event_read_sample_ok:OK #135/2 perf_event_read_sample/perf_event_read_sample_invalid:OK #135 perf_event_read_sample:OK Signed-off-by: Namhyung Kim --- .../selftests/bpf/prog_tests/perf_sample.c | 167 ++++++++++++++++++ .../selftests/bpf/progs/test_perf_sample.c | 33 ++++ 2 files changed, 200 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/perf_sample.c create mode 100644 tools/testing/selftests/bpf/progs/test_perf_sample.c diff --git a/tools/testing/selftests/bpf/prog_tests/perf_sample.c b/tools/testing/selftests/bpf/prog_tests/perf_sample.c new file mode 100644 index 000000000000..dc1e88711e23 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/perf_sample.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include + +#include +#include "test_perf_sample.skel.h" + +#ifndef noinline +#define noinline __attribute__((noinline)) +#endif + +/* treat user-stack data as invalid (for testing only) */ +#define PERF_SAMPLE_INVALID PERF_SAMPLE_STACK_USER + +#define PERF_MMAP_SIZE 8192 +#define DATA_MMAP_SIZE 4096 + +static int perf_fd = -1; +static void *perf_ringbuf; +static struct test_perf_sample *skel; + +static int open_perf_event(u64 sample_flags) +{ + struct perf_event_attr attr = { + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_PAGE_FAULTS, + .sample_type = sample_flags, + .sample_period = 1, + .disabled = 1, + .size = sizeof(attr), + }; + int fd; + void *ptr; + + fd = syscall(SYS_perf_event_open, &attr, 0, -1, -1, 0); + if (!ASSERT_GT(fd, 0, "perf_event_open")) + return -1; + + ptr = mmap(NULL, PERF_MMAP_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + if (!ASSERT_NEQ(ptr, MAP_FAILED, "mmap")) { + close(fd); + return -1; + } + + perf_fd = fd; + perf_ringbuf = ptr; + + return 0; +} + +static void close_perf_event(void) +{ + if (perf_fd == -1) + return; + + munmap(perf_ringbuf, PERF_MMAP_SIZE); + close(perf_fd); + + perf_fd = -1; + perf_ringbuf = NULL; +} + +static noinline void *trigger_perf_event(void) +{ + int *buf = mmap(NULL, DATA_MMAP_SIZE, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0); + + if (!ASSERT_NEQ(buf, MAP_FAILED, "mmap")) + return NULL; + + ioctl(perf_fd, PERF_EVENT_IOC_ENABLE); + + /* it should generate a page fault which triggers the perf_event */ + *buf = 1; + + ioctl(perf_fd, PERF_EVENT_IOC_DISABLE); + + munmap(buf, DATA_MMAP_SIZE); + + /* return the map address to check the sample addr */ + return buf; +} + +/* check if the perf ringbuf has a sample data */ +static int check_perf_event(void) +{ + struct perf_event_mmap_page *page = perf_ringbuf; + struct perf_event_header *hdr; + + if (page->data_head == page->data_tail) + return 0; + + hdr = perf_ringbuf + page->data_offset; + + if (hdr->type != PERF_RECORD_SAMPLE) + return 0; + + return 1; +} + +static void setup_perf_sample_bpf_skel(void) +{ + struct bpf_link *link; + + skel = test_perf_sample__open_and_load(); + if (!ASSERT_OK_PTR(skel, "test_perf_sample_open_and_load")) + return; + + link = bpf_program__attach_perf_event(skel->progs.perf_sample_filter, perf_fd); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_perf_event")) + return; +} + +static void clean_perf_sample_bpf_skel(void) +{ + test_perf_sample__detach(skel); + test_perf_sample__destroy(skel); +} + +static void test_perf_event_read_sample_ok(void) +{ + u64 flags = PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_ADDR; + uintptr_t map_addr; + + if (open_perf_event(flags) < 0) + return; + setup_perf_sample_bpf_skel(); + map_addr = (uintptr_t)trigger_perf_event(); + + ASSERT_EQ(check_perf_event(), 1, "number of sample"); + ASSERT_EQ(skel->bss->sample_addr, map_addr, "sample addr"); + ASSERT_EQ((int)skel->bss->sample_pid, getpid(), "sample pid"); + /* just assume the IP in (trigger_perf_event, +4096) */ + ASSERT_GT(skel->bss->sample_ip, (uintptr_t)trigger_perf_event, "sample ip"); + ASSERT_LT(skel->bss->sample_ip, (uintptr_t)trigger_perf_event + 4096, "sample ip"); + + clean_perf_sample_bpf_skel(); + close_perf_event(); +} + +static void test_perf_event_read_sample_invalid(void) +{ + u64 flags = PERF_SAMPLE_INVALID; + + if (open_perf_event(flags) < 0) + return; + setup_perf_sample_bpf_skel(); + trigger_perf_event(); + + ASSERT_EQ(check_perf_event(), 0, "number of sample"); + + clean_perf_sample_bpf_skel(); + close_perf_event(); +} + +void test_perf_event_read_sample(void) +{ + if (test__start_subtest("perf_event_read_sample_ok")) + test_perf_event_read_sample_ok(); + if (test__start_subtest("perf_event_read_sample_invalid")) + test_perf_event_read_sample_invalid(); +} diff --git a/tools/testing/selftests/bpf/progs/test_perf_sample.c b/tools/testing/selftests/bpf/progs/test_perf_sample.c new file mode 100644 index 000000000000..b1f498d447b9 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_perf_sample.c @@ -0,0 +1,33 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2022 Google + +#include "vmlinux.h" +#include + +unsigned long long sample_ip; +unsigned long long sample_pid; +unsigned long long sample_addr; + +void *bpf_cast_to_kern_ctx(void *) __ksym; + +#define SAMPLE_FLAGS (PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_ADDR) + +SEC("perf_event") +int perf_sample_filter(void *ctx) +{ + struct bpf_perf_event_data_kern *kctx; + + kctx = bpf_cast_to_kern_ctx(ctx); + + if ((kctx->event->attr.sample_type & SAMPLE_FLAGS) != SAMPLE_FLAGS) + return 0; + + sample_ip = kctx->data->ip; + sample_pid = kctx->data->tid_entry.pid; + sample_addr = kctx->data->addr; + + /* generate sample data */ + return 1; +} + +char _license[] SEC("license") = "GPL";