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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3288DC6FD1C for ; Wed, 22 Mar 2023 06:45:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230106AbjCVGpZ (ORCPT ); Wed, 22 Mar 2023 02:45:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230026AbjCVGoz (ORCPT ); Wed, 22 Mar 2023 02:44:55 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CE6C5BDBE for ; Tue, 21 Mar 2023 23:44:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1679467442; x=1711003442; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=filNSMPYZWlECjrivq6FRSVbw/cDhlvzd0VGwFLNwtE=; b=H+YT0WmkxVuMvxeD7mtpltvdg4+gqqzUVv3Jzf3I2DmbxEumPVte9uPu dxpgz1INjId4D/Zzv50AmzHr7JIeu3WTQ07mYwntLW9oq0sda96KINU1p w84HmqyCVWoyGgNPd9NfCzLKHJ0UQGtPK998NrnC3KB+SBi8BaUrX0g3M /9P0DKXvlkL9UlaCp5RTGZkkzBMM4X5MoLALEfoQqulSgB/eh32D93P3U 03MHNskb8l8oLZ4tJNDzW9X6BdVpvF5eYrxkGJI07d/Eh3SD8wULh3mr6 fVzl0XPyVRPMVy2VoE7a0HQGuCLC5Yyk1lf16WCx7F7HKabv/bz2BpkgU g==; X-IronPort-AV: E=McAfee;i="6600,9927,10656"; a="366877607" X-IronPort-AV: E=Sophos;i="5.98,281,1673942400"; d="scan'208";a="366877607" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Mar 2023 23:43:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10656"; a="746187349" X-IronPort-AV: E=Sophos;i="5.98,281,1673942400"; d="scan'208";a="746187349" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga008.fm.intel.com with ESMTP; 21 Mar 2023 23:43:53 -0700 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, bigeasy@linutronix.de, yujie.liu@intel.com, shan.kang@intel.com Subject: [PATCH v2 1/1] x86/vdso: choose the right GDT_ENTRY_CPUNODE for 32-bit getcpu() on 64-bit kernel Date: Tue, 21 Mar 2023 23:17:58 -0700 Message-Id: <20230322061758.10639-1-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The vDSO getcpu() reads CPU ID from the GDT_ENTRY_CPUNODE entry when the RDPID instruction is not available. And GDT_ENTRY_CPUNODE is defined as 28 on 32-bit Linux kernel and 15 on 64-bit. But the 32-bit getcpu() on 64-bit Linux kernel is compiled with 32-bit Linux kernel GDT_ENTRY_CPUNODE, i.e., 28, beyond the 64-bit Linux kernel GDT limit. Thus, it just fails _silently_. When BUILD_VDSO32_64 is defined, choose the 64-bit Linux kernel GDT definitions to compile the 32-bit getcpu(). Fixes: 877cff5296faa6e ("x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu") Reported-by: kernel test robot https://lore.kernel.org/oe-lkp/202303020903.b01fd1de-yujie.liu@intel.com/ Reported-by: Shan Kang Signed-off-by: Xin Li --- Change since v1: * Define all of the GDT_ENTRY_* macros in *one* place, then make that *one* place depend on BUILD_VDSO32_64 (Dave Hansen). --- arch/x86/include/asm/segment.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index 794f69625780..9d6411c65920 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -56,7 +56,7 @@ #define GDT_ENTRY_INVALID_SEG 0 -#ifdef CONFIG_X86_32 +#if defined(CONFIG_X86_32) && !defined(BUILD_VDSO32_64) /* * The layout of the per-CPU GDT under Linux: * -- 2.34.1