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=-7.8 required=3.0 tests=DATE_IN_PAST_06_12, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 32B63C04AAE for ; Wed, 8 May 2019 17:03:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E08021530 for ; Wed, 8 May 2019 17:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729101AbfEHRDe (ORCPT ); Wed, 8 May 2019 13:03:34 -0400 Received: from mga03.intel.com ([134.134.136.65]:5322 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728993AbfEHRDF (ORCPT ); Wed, 8 May 2019 13:03:05 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 May 2019 10:03:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,446,1549958400"; d="scan'208";a="169697595" Received: from chang-linux-3.sc.intel.com ([172.25.66.171]) by fmsmga002.fm.intel.com with ESMTP; 08 May 2019 10:03:04 -0700 From: "Chang S. Bae" To: Andy Lutomirski , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andi Kleen Cc: Ravi Shankar , "Chang S . Bae" , LKML , Andi Kleen Subject: [PATCH v7 15/18] selftests/x86/fsgsbase: Test ptracer-induced GSBASE write with FSGSBASE Date: Wed, 8 May 2019 03:02:30 -0700 Message-Id: <1557309753-24073-16-git-send-email-chang.seok.bae@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1557309753-24073-1-git-send-email-chang.seok.bae@intel.com> References: <1557309753-24073-1-git-send-email-chang.seok.bae@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This validates that GS and GSBASE are independently preserved in ptracer commands. Suggested-by: Andy Lutomirski Signed-off-by: Chang S. Bae Cc: Thomas Gleixner Cc: Ingo Molnar Cc: H. Peter Anvin Cc: Andi Kleen --- tools/testing/selftests/x86/fsgsbase.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c index daff504..7cd36be 100644 --- a/tools/testing/selftests/x86/fsgsbase.c +++ b/tools/testing/selftests/x86/fsgsbase.c @@ -470,7 +470,7 @@ static void test_ptrace_write_gsbase(void) wait(&status); if (WSTOPSIG(status) == SIGTRAP) { - unsigned long gs; + unsigned long gs, base; unsigned long gs_offset = USER_REGS_OFFSET(gs); unsigned long base_offset = USER_REGS_OFFSET(gs_base); @@ -486,6 +486,7 @@ static void test_ptrace_write_gsbase(void) err(1, "PTRACE_POKEUSER"); gs = ptrace(PTRACE_PEEKUSER, child, gs_offset, NULL); + base = ptrace(PTRACE_PEEKUSER, child, base_offset, NULL); /* * In a non-FSGSBASE system, the nonzero selector will load @@ -496,8 +497,14 @@ static void test_ptrace_write_gsbase(void) if (gs != 0x7) { nerrs++; printf("[FAIL]\tGS changed to %lx\n", gs); + } else if (have_fsgsbase && (base != 0xFF)) { + nerrs++; + printf("[FAIL]\tGSBASE changed to %lx\n", base); } else { - printf("[OK]\tGS remained 0x7\n"); + printf("[OK]\tGS remained 0x7 %s"); + if (have_fsgsbase) + printf("and GSBASE changed to 0xFF"); + printf("\n"); } } -- 2.7.4