From patchwork Fri Feb 4 19:17:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reinette Chatre X-Patchwork-Id: 12735477 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 2E3ECC433FE for ; Fri, 4 Feb 2022 19:18:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232299AbiBDTSC (ORCPT ); Fri, 4 Feb 2022 14:18:02 -0500 Received: from mga11.intel.com ([192.55.52.93]:61194 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232259AbiBDTSC (ORCPT ); Fri, 4 Feb 2022 14:18:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644002282; x=1675538282; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=hSJGQlS3PL8jbOVhKeoI5KEQF3vEjiDdnv98cafGarE=; b=P2vOAFdX0BEzzPmO6u5f3hqQzAxFW1FA8piav8dZ6zVLXXuYdmUlZL6E 35XndsdzkeOKEVwAoEpBi1mrJD6J1eMh/YFGMYYCtXU0rn6TK91TkyiIl FfpCNTVSq5/3qAUTkw4yU0Be/s1CPMHqLd4lnPKgkEZvvX46aFBW7CurX k4rLgNs3rMxR0jyI0O1zVV8c8e/zPx4onHvWhBRqC+8nkXA2tVQ+0FN88 7ScmN7eHxovF00wx2zs+5pGzth83p8GEPUkqdSFKkSDOLrsGbq3jaylL+ yonF10znT+Il/TPo8dSCLReYjT6hNGzai5C+GA0LwK1XTtKKq0IOuGjUq g==; X-IronPort-AV: E=McAfee;i="6200,9189,10248"; a="246017070" X-IronPort-AV: E=Sophos;i="5.88,343,1635231600"; d="scan'208";a="246017070" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2022 11:18:00 -0800 X-IronPort-AV: E=Sophos;i="5.88,343,1635231600"; d="scan'208";a="524412819" Received: from rchatre-ws.ostc.intel.com ([10.54.69.144]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2022 11:18:00 -0800 From: Reinette Chatre To: shuah@kernel.org, linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Reinette Chatre , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , x86@kernel.org Subject: [PATCH 3/3] selftests/x86/corrupt_xstate_header: Use existing __cpuid_count() macro Date: Fri, 4 Feb 2022 11:17:11 -0800 Message-Id: <6bc87ebe3a62ad2ee31a5e5952897c48a8ef2d77.1644000145.git.reinette.chatre@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org gcc as well as clang makes the __cpuid_count() macro available via cpuid.h to conveniently call the CPUID instruction. Below is a copy of the macro as found in cpuid.h: #define __cpuid_count(level, count, a, b, c, d) \ __asm__ ("cpuid\n\t" \ : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \ : "0" (level), "2" (count)) The corrupt_xstate_header test contains a local function used as wrapper to the CPUID instruction. One difference between the corrupt_xstate_header implementation and the macro from cpuid.h is that the corrupt_xstate_header implementation provides the "volatile" qualifier to the asm() call. The "volatile" qualifier is necessary when CPUID has side effects and thus any optimizations should be avoided. CPUID is used in the corrupt_xstate_header test to query the system for its XSAVE/XRSTOR support, a query without side effect, the "volatile" qualifier is thus not required and the macro from cpuid.h can be used instead. Remove the duplicated wrapper to CPUID and use __cpuid_count() from cpuid.h instead. Cc: Andy Lutomirski Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: x86@kernel.org Signed-off-by: Reinette Chatre --- .../selftests/x86/corrupt_xstate_header.c | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) diff --git a/tools/testing/selftests/x86/corrupt_xstate_header.c b/tools/testing/selftests/x86/corrupt_xstate_header.c index ab8599c10ce5..7a877612bc98 100644 --- a/tools/testing/selftests/x86/corrupt_xstate_header.c +++ b/tools/testing/selftests/x86/corrupt_xstate_header.c @@ -7,6 +7,7 @@ #define _GNU_SOURCE +#include #include #include #include @@ -17,25 +18,11 @@ #include #include -static inline void __cpuid(unsigned int *eax, unsigned int *ebx, - unsigned int *ecx, unsigned int *edx) -{ - asm volatile( - "cpuid;" - : "=a" (*eax), - "=b" (*ebx), - "=c" (*ecx), - "=d" (*edx) - : "0" (*eax), "2" (*ecx)); -} - static inline int xsave_enabled(void) { unsigned int eax, ebx, ecx, edx; - eax = 0x1; - ecx = 0x0; - __cpuid(&eax, &ebx, &ecx, &edx); + __cpuid_count(0x1, 0x0, eax, ebx, ecx, edx); /* Is CR4.OSXSAVE enabled ? */ return ecx & (1U << 27);