Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756437Ab2HXVPl (ORCPT ); Fri, 24 Aug 2012 17:15:41 -0400 Received: from mga03.intel.com ([143.182.124.21]:7595 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753464Ab2HXVPd (ORCPT ); Fri, 24 Aug 2012 17:15:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,304,1344236400"; d="scan'208";a="190967384" From: Suresh Siddha To: hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, andreas.herrmann3@amd.com, bp@amd64.org, robert.richter@amd.com Cc: linux-kernel@vger.kernel.org, Suresh Siddha Subject: [PATCH 2/6] x86, fpu: remove unnecessary user_fpu_end() in save_xstate_sig() Date: Fri, 24 Aug 2012 14:12:58 -0700 Message-Id: <1345842782-24175-3-git-send-email-suresh.b.siddha@intel.com> X-Mailer: git-send-email 1.7.6.5 In-Reply-To: <1345842782-24175-1-git-send-email-suresh.b.siddha@intel.com> References: <1345842782-24175-1-git-send-email-suresh.b.siddha@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2121 Lines: 61 Few lines below we do drop_fpu() which is more safer. Remove the unnecessary user_fpu_end() in save_xstate_sig(), which allows the drop_fpu() to ignore any pending exceptions from the user-space and drop the current fpu. Signed-off-by: Suresh Siddha --- arch/x86/include/asm/fpu-internal.h | 17 +++-------------- arch/x86/kernel/xsave.c | 1 - 2 files changed, 3 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index fe95ad0..fac39e9 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -412,22 +412,11 @@ static inline void __drop_fpu(struct task_struct *tsk) } /* - * The actual user_fpu_begin/end() functions - * need to be preemption-safe. + * Need to be preemption-safe. * - * NOTE! user_fpu_end() must be used only after you - * have saved the FP state, and user_fpu_begin() must - * be used only immediately before restoring it. - * These functions do not do any save/restore on - * their own. + * NOTE! user_fpu_begin() must be used only immediately before restoring + * it. This function does not do any save/restore on their own. */ -static inline void user_fpu_end(void) -{ - preempt_disable(); - __thread_fpu_end(current); - preempt_enable(); -} - static inline void user_fpu_begin(void) { preempt_disable(); diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index 6cfc7d9..f0bb844 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -254,7 +254,6 @@ int save_xstate_sig(void __user *buf, void __user *buf_fx, int size) /* Update the thread's fxstate to save the fsave header. */ if (ia32_fxstate) fpu_fxsave(&tsk->thread.fpu); - user_fpu_end(); } else { sanitize_i387_state(tsk); if (__copy_to_user(buf_fx, xsave, xstate_size)) -- 1.7.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/