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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 EC6C9C43381 for ; Mon, 25 Feb 2019 21:41:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B84FA20652 for ; Mon, 25 Feb 2019 21:41:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130908; bh=sBErCJTa8jm6WC72b4Jzz0kOQVnGNm0VyJMYQJAS57k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SGYZXb4scLvR2r9VHe/KK/ghTGRsMGqAm6J5jDsHCIWQZRu5N28alLim/TwDxbTRj p9aMxm6y7J4pK3g/qMHy940urq8Ed3hvGqpKKuzQVbyfa3vswqviGmtHBzxSsrNNhF OYWRlahMwo1PTONx7OZGp1dKGja72L2Z7E/NhF5U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732413AbfBYVdR (ORCPT ); Mon, 25 Feb 2019 16:33:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:39490 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728907AbfBYVdP (ORCPT ); Mon, 25 Feb 2019 16:33:15 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CDF64217F5; Mon, 25 Feb 2019 21:33:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130394; bh=sBErCJTa8jm6WC72b4Jzz0kOQVnGNm0VyJMYQJAS57k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M/ZcSlPbbwezaC5vhdx7pv/ybqccehtREzlMy7g5KokQ+lcWGOaVtontUwkb60hfc W28KDP7IhcsxqRkoZsAnHfIsIbBY1WVNkqsurKNIqFu7Ggi70E4JL2lyK4S2kTnvm9 nZANwRE4P/Uls3zWNLemg2HrmwNdHZDATL/ThzAg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Song Liu , Stanislav Fomichev , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.20 108/183] selftests/bpf: retry tests that expect build-id Date: Mon, 25 Feb 2019 22:11:21 +0100 Message-Id: <20190225195112.895012140@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190225195054.748060397@linuxfoundation.org> References: <20190225195054.748060397@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit f67ad87ab3120e82845521b18a2b99273a340308 ] While running test_progs in a loop I found out that I'm sometimes hitting "Didn't find expected build ID from the map" error. Looking at stack_map_get_build_id_offset() it seems that it is racy (by design) and can sometimes return BPF_STACK_BUILD_ID_IP (i.e. can't trylock current->mm->mmap_sem). Let's retry this test a single time. Fixes: 13790d1cc72c ("bpf: add selftest for stackmap with build_id in NMI context") Acked-by: Song Liu Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- tools/testing/selftests/bpf/test_progs.c | 30 ++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index 6ac7232b0fdeb..3ec4ce156074c 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -1136,7 +1136,9 @@ static void test_stacktrace_build_id(void) int i, j; struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH]; int build_id_matches = 0; + int retry = 1; +retry: err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno)) goto out; @@ -1249,6 +1251,19 @@ static void test_stacktrace_build_id(void) previous_key = key; } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0); + /* stack_map_get_build_id_offset() is racy and sometimes can return + * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID; + * try it one more time. + */ + if (build_id_matches < 1 && retry--) { + ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); + close(pmu_fd); + bpf_object__close(obj); + printf("%s:WARN:Didn't find expected build ID from the map, retrying\n", + __func__); + goto retry; + } + if (CHECK(build_id_matches < 1, "build id match", "Didn't find expected build ID from the map\n")) goto disable_pmu; @@ -1289,7 +1304,9 @@ static void test_stacktrace_build_id_nmi(void) int i, j; struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH]; int build_id_matches = 0; + int retry = 1; +retry: err = bpf_prog_load(file, BPF_PROG_TYPE_PERF_EVENT, &obj, &prog_fd); if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno)) return; @@ -1384,6 +1401,19 @@ static void test_stacktrace_build_id_nmi(void) previous_key = key; } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0); + /* stack_map_get_build_id_offset() is racy and sometimes can return + * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID; + * try it one more time. + */ + if (build_id_matches < 1 && retry--) { + ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); + close(pmu_fd); + bpf_object__close(obj); + printf("%s:WARN:Didn't find expected build ID from the map, retrying\n", + __func__); + goto retry; + } + if (CHECK(build_id_matches < 1, "build id match", "Didn't find expected build ID from the map\n")) goto disable_pmu; -- 2.19.1