From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753041AbcEJXh7 (ORCPT ); Tue, 10 May 2016 19:37:59 -0400 Received: from mga11.intel.com ([192.55.52.93]:44892 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753094AbcEJXes (ORCPT ); Tue, 10 May 2016 19:34:48 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,606,1455004800"; d="scan'208";a="100873283" From: Yu-cheng Yu To: linux-kernel@vger.kernel.org, x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar Cc: Dave Hansen , Andy Lutomirski , Borislav Petkov , Sai Praneeth Prakhya , "Ravi V. Shankar" , Fenghua Yu , Yu-cheng Yu Subject: [PATCH v6 11/13] x86/xsaves: When a disabled xstate component offset is requested, return NULL Date: Tue, 10 May 2016 16:30:03 -0700 Message-Id: <32f956933af74045ae503ae90437fc83b92d1ba8.1462914897.git.yu-cheng.yu@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is an error to request a disabled XSAVE/XSAVES component address. For that case, make __raw_xsave_addr() return a NULL and issue a warning. Signed-off-by: Yu-cheng Yu --- arch/x86/kernel/fpu/xstate.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index a913d4e..7c2cdc4 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -761,6 +761,11 @@ void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask) { int feature_nr = fls64(xstate_feature_mask) - 1; + if (!xfeature_enabled(feature_nr)) { + WARN_ON_FPU(1); + return NULL; + } + return (void *)xsave + xstate_comp_offsets[feature_nr]; } -- 1.9.1