From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758888AbcGKNTa (ORCPT ); Mon, 11 Jul 2016 09:19:30 -0400 Received: from mga04.intel.com ([192.55.52.120]:2997 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753697AbcGKNRz (ORCPT ); Mon, 11 Jul 2016 09:17:55 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,346,1464678000"; d="scan'208";a="1019448927" From: "Fenghua Yu" To: "Ingo Molnar" , "Thomas Gleixner" , "H. Peter Anvin" , "Dave Hansen" , "Ravi V Shankar" Cc: Yu-cheng Yu , "Fenghua Yu" , "x86" , "linux-kernel" Subject: [PATCH 1/4] x86/fpu/xstate: Fix __fpu_restore_sig() for XSAVES Date: Mon, 11 Jul 2016 09:18:54 -0700 Message-Id: <1468253937-40008-2-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 1.8.0.1 In-Reply-To: <1468253937-40008-1-git-send-email-fenghua.yu@intel.com> References: <1468253937-40008-1-git-send-email-fenghua.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yu-cheng Yu When the kernel is using XSAVES compacted format, we cannot do __copy_from_user() from a signal frame, which has standard-format data. Fix it by using copyin_to_xsaves(), which converts between formats and filters out all supervisor states that we do not allow userspace to write. Signed-off-by: Yu-cheng Yu Signed-off-by: Fenghua Yu Reviewed-by: Dave Hansen --- arch/x86/kernel/fpu/signal.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 8aa96cb..9e231d8 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -323,8 +323,15 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) */ fpu__drop(fpu); - if (__copy_from_user(&fpu->state.xsave, buf_fx, state_size) || - __copy_from_user(&env, buf, sizeof(env))) { + if (using_compacted_format()) { + err = copyin_to_xsaves(NULL, buf_fx, + &fpu->state.xsave); + } else { + err = __copy_from_user(&fpu->state.xsave, + buf_fx, state_size); + } + + if (err || __copy_from_user(&env, buf, sizeof(env))) { fpstate_init(&fpu->state); trace_x86_fpu_init_state(fpu); err = -1; -- 2.5.0