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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 CEA47C4646D for ; Mon, 6 Aug 2018 13:27:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9311B21A2D for ; Mon, 6 Aug 2018 13:27:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9311B21A2D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730079AbeHFPgj (ORCPT ); Mon, 6 Aug 2018 11:36:39 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:43908 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729722AbeHFPgj (ORCPT ); Mon, 6 Aug 2018 11:36:39 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w76DNxZl105767 for ; Mon, 6 Aug 2018 09:27:32 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2kpppdhh9x-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 06 Aug 2018 09:27:31 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 6 Aug 2018 14:27:26 +0100 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w76DRPGP43647176 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 6 Aug 2018 13:27:25 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3F284AE058; Mon, 6 Aug 2018 16:27:20 +0100 (BST) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E16A4AE053; Mon, 6 Aug 2018 16:27:19 +0100 (BST) Received: from localhost (unknown [9.152.212.144]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Mon, 6 Aug 2018 16:27:19 +0100 (BST) Date: Mon, 6 Aug 2018 15:27:23 +0200 From: Vasily Gorbik To: Mathieu Desnoyers , Shuah Khan , Thomas Gleixner Cc: Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v2 1/1] rseq/selftests: add __rseq_abi misalignment check References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-TM-AS-GCONF: 00 x-cbid: 18080613-0028-0000-0000-000002E634AA X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18080613-0029-0000-0000-0000239E56FA Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-06_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808060143 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kernel rseq syscall expects that struct rseq is 32 bytes aligned and returns EINVAL otherwise. Even though __rseq_abi is declared as static and proper aligned attribute is present __rseq_abi is a part of thread local storage. It turns out that on some platforms TLS itself is not properly aligned (at least for threads created), which is a glibc nptl bug and should be eventually fixed and backported. But in a meanwhile add __rseq_abi misalignment check, which would detect this situation and skip rseq test with some user friendly message. glibc bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23403 Signed-off-by: Vasily Gorbik --- tools/testing/selftests/rseq/rseq.c | 20 +++++++++++++++++++ .../testing/selftests/rseq/run_param_test.sh | 4 ++-- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c index 4847e97ed049..3de7f0e7442e 100644 --- a/tools/testing/selftests/rseq/rseq.c +++ b/tools/testing/selftests/rseq/rseq.c @@ -64,6 +64,24 @@ static int sys_rseq(volatile struct rseq *rseq_abi, uint32_t rseq_len, return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig); } +/* + * rseq syscall might fail on some platforms due to wrong alignment of TLS + * variables: + * https://sourceware.org/bugzilla/show_bug.cgi?id=23403 + * + * check if glibc bug is present and skip the test in this case + */ +static void assert_rseq_abi_aligned(void) +{ + if ((unsigned long)&__rseq_abi & (__alignof__(__rseq_abi) - 1)) { + fputs("__rseq_abi is not properly aligned, which is a known\n" + "glibc nptl bug (https://sourceware.org/bugzilla/show_bug.cgi?id=23403).\n" + "You need a fixed version of glibc to run this test.\n", + stderr); + exit(4); /* skip this test */ + } +} + int rseq_register_current_thread(void) { int rc, ret = 0; @@ -72,6 +90,7 @@ int rseq_register_current_thread(void) signal_off_save(&oldset); if (refcount++) goto end; + assert_rseq_abi_aligned(); rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), 0, RSEQ_SIG); if (!rc) { assert(rseq_current_cpu_raw() >= 0); @@ -94,6 +113,7 @@ int rseq_unregister_current_thread(void) signal_off_save(&oldset); if (--refcount) goto end; + assert_rseq_abi_aligned(); rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), RSEQ_FLAG_UNREGISTER, RSEQ_SIG); if (!rc) diff --git a/tools/testing/selftests/rseq/run_param_test.sh b/tools/testing/selftests/rseq/run_param_test.sh index 3acd6d75ff9f..56caf5e3de3e 100755 --- a/tools/testing/selftests/rseq/run_param_test.sh +++ b/tools/testing/selftests/rseq/run_param_test.sh @@ -34,9 +34,9 @@ function do_tests() local i=0 while [ "$i" -lt "${#TEST_LIST[@]}" ]; do echo "Running test ${TEST_NAME[$i]}" - ./param_test ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1 + ./param_test ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit $? echo "Running compare-twice test ${TEST_NAME[$i]}" - ./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1 + ./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit $? let "i++" done } -- 2.18.0.13.gd42ae10