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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 BB362C432BE for ; Wed, 1 Sep 2021 04:09:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BD0960ED4 for ; Wed, 1 Sep 2021 04:09:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229846AbhIAEJ4 (ORCPT ); Wed, 1 Sep 2021 00:09:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbhIAEJz (ORCPT ); Wed, 1 Sep 2021 00:09:55 -0400 Received: from mail-yb1-xb33.google.com (mail-yb1-xb33.google.com [IPv6:2607:f8b0:4864:20::b33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 155EFC061575; Tue, 31 Aug 2021 21:08:59 -0700 (PDT) Received: by mail-yb1-xb33.google.com with SMTP id z18so2560699ybg.8; Tue, 31 Aug 2021 21:08:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4T6MpzYWaQVP7um/e/Du343DWTOvDE+C03sra0qPBIk=; b=WGBmb8M/vFrlx3/toZSSDbVUD9cViBwQl1L2jjh9j/wzYwyKMSWmyCreoQBYHhBqJQ 3BxQaCdVs1AwUVzJzUO63+RJiucH+Q4R3yEvITR0Iaq8iShJUHNsx78n4AwJ8JDVHzfu abr9jg1DtNXvOtVUYuzlEHqNtNtz7FxvgdK+WDCjtBJsSTekL/sBf2G2UA30lrKLn3NX PQ/kTneSQchfHlpw1zuEO3gtD2WdrhPql0tmp/f5nPTJjodc6jbYLwGRGZm6wYTgnZss 9l21FjpO2C1HwOpPMYxpNsi0bbwV0/TMCF9CJ95v3GSxtSu5APFulU/+2A+aBIyHVmVB Cczw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4T6MpzYWaQVP7um/e/Du343DWTOvDE+C03sra0qPBIk=; b=cqZojPVL1pQiw986u05RrIX8XBo1RxkbBcK9kJ8mXSHwK2bPo4N3lKxSNV+cY78Jxu qks1r3e7Nce7sILB7ZB1Dw4oAf52bFpODCmnAkSC7FkAQDe4COXsErOdbyHqV0w1xC+u tzA1bcUWJzKA3y+Znl+OuRtNqzLzpz+LTXE84xEky5l/3nHeNkpMHEbQssYG6ETF/Qp+ u6VVxpZI9eDOudjnXUYQVS4tALGeEXE+dhsPlkGXaqeqZGXhNwFQvGBl0jbIr36PWLi3 pwm6l7iup2gAmEWNxnsyYqV32YwKgPo7yuCCKQm1sBxdQs1B2YN15D+tuXmdkenbwHgE LwzA== X-Gm-Message-State: AOAM531OBa52AVoqbwEDinWy0OPQaz8L0Jeno6P9Es3nnUJ9ygTRLRHs N8Qb9EbFxT4vlOExOR5JhQ7Wd7jCp5fLYuq83+c= X-Google-Smtp-Source: ABdhPJx0KQievz8CGByVCBB9wA9HsV7RMN304eYLbOtjjIXRLcrg9gUf8unSMQ0zCkQ6R0wNKFLyjwssmsKlAH8lwWg= X-Received: by 2002:a25:4941:: with SMTP id w62mr35416729yba.230.1630469338253; Tue, 31 Aug 2021 21:08:58 -0700 (PDT) MIME-Version: 1.0 References: <20210901003517.3953145-1-songliubraving@fb.com> <20210901003517.3953145-4-songliubraving@fb.com> In-Reply-To: <20210901003517.3953145-4-songliubraving@fb.com> From: Andrii Nakryiko Date: Tue, 31 Aug 2021 21:08:47 -0700 Message-ID: Subject: Re: [PATCH v4 bpf-next 3/3] selftests/bpf: add test for bpf_get_branch_snapshot To: Song Liu Cc: bpf , open list , Arnaldo Carvalho de Melo , Peter Ziljstra , Ingo Molnar , Kajol Jain , Kernel Team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Tue, Aug 31, 2021 at 7:01 PM Song Liu wrote: > > This test uses bpf_get_branch_snapshot from a fexit program. The test uses > a target function (bpf_testmod_loop_test) and compares the record against > kallsyms. If there isn't enough record matching kallsyms, the test fails. > > Signed-off-by: Song Liu > --- LGTM, few minor nits below Acked-by: Andrii Nakryiko > .../selftests/bpf/bpf_testmod/bpf_testmod.c | 14 ++- > .../bpf/prog_tests/get_branch_snapshot.c | 101 ++++++++++++++++++ > .../selftests/bpf/progs/get_branch_snapshot.c | 44 ++++++++ > tools/testing/selftests/bpf/trace_helpers.c | 37 +++++++ > tools/testing/selftests/bpf/trace_helpers.h | 5 + > 5 files changed, 200 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c > create mode 100644 tools/testing/selftests/bpf/progs/get_branch_snapshot.c > [...] > + > +void test_get_branch_snapshot(void) > +{ > + struct get_branch_snapshot *skel = NULL; > + int err; > + > + if (create_perf_events()) { > + test__skip(); /* system doesn't support LBR */ > + goto cleanup; > + } > + > + skel = get_branch_snapshot__open_and_load(); > + if (!ASSERT_OK_PTR(skel, "get_branch_snapshot__open_and_load")) > + goto cleanup; > + > + err = kallsyms_find("bpf_testmod_loop_test", &skel->bss->address_low); > + if (!ASSERT_OK(err, "kallsyms_find")) > + goto cleanup; > + > + err = kallsyms_find_next("bpf_testmod_loop_test", &skel->bss->address_high); > + if (!ASSERT_OK(err, "kallsyms_find_next")) > + goto cleanup; > + > + err = get_branch_snapshot__attach(skel); > + if (!ASSERT_OK(err, "get_branch_snapshot__attach")) > + goto cleanup; > + > + /* trigger the program */ > + system("cat /sys/kernel/bpf_testmod > /dev/null 2>& 1"); ugh :( see prog_tests/module_attach.c, we can extract and reuse trigger_module_test_read() and trigger_module_test_write() > + > + if (skel->bss->total_entries < 16) { > + /* too few entries for the hit/waste test */ > + test__skip(); > + goto cleanup; > + } > + [...] > +SEC("fexit/bpf_testmod_loop_test") > +int BPF_PROG(test1, int n, int ret) > +{ > + long i; > + > + total_entries = bpf_get_branch_snapshot(entries, sizeof(entries), 0); > + total_entries /= sizeof(struct perf_branch_entry); > + > + bpf_printk("total_entries %lu\n", total_entries); > + > + for (i = 0; i < PERF_MAX_BRANCH_SNAPSHOT; i++) { > + if (i >= total_entries) > + break; > + if (in_range(entries[i].from) && in_range(entries[i].to)) > + test1_hits++; > + else if (!test1_hits) > + wasted_entries++; > + bpf_printk("i %d from %llx to %llx", i, entries[i].from, > + entries[i].to); debug leftovers? this will be polluting trace_pipe unnecessarily; same for above total_entries bpf_printk() > + } > + return 0; > +} > diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c > index e7a19b04d4eaf..5100a169b72b1 100644 > --- a/tools/testing/selftests/bpf/trace_helpers.c > +++ b/tools/testing/selftests/bpf/trace_helpers.c > @@ -1,4 +1,5 @@ > // SPDX-License-Identifier: GPL-2.0 > +#include > #include > #include > #include > @@ -117,6 +118,42 @@ int kallsyms_find(const char *sym, unsigned long long *addr) > return err; > } > [...]