From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755617AbdKBIBJ (ORCPT ); Thu, 2 Nov 2017 04:01:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:39184 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755601AbdKBIBE (ORCPT ); Thu, 2 Nov 2017 04:01:04 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5EEB32193A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=luto@kernel.org From: Andy Lutomirski To: X86 ML Cc: Borislav Petkov , "linux-kernel@vger.kernel.org" , Brian Gerst , Dave Hansen , Linus Torvalds , Andy Lutomirski Subject: [PATCH v2 20/20] x86/traps: Use a new on_thread_stack() helper to clean up an assertion Date: Thu, 2 Nov 2017 00:59:17 -0700 Message-Id: <856b15bee1f55017b8f79d3758b0d51c48a08cf8.1509609304.git.luto@kernel.org> X-Mailer: git-send-email 2.13.6 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 Let's keep the stack-related logic together rather than open-coding a comparison in an assertion in the traps code. Reviewed-by: Borislav Petkov Signed-off-by: Andy Lutomirski --- arch/x86/include/asm/processor.h | 6 ++++++ arch/x86/kernel/traps.c | 3 +-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index ae2ae6d80674..f10dae14f951 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -541,6 +541,12 @@ static inline unsigned long current_top_of_stack(void) #endif } +static inline bool on_thread_stack(void) +{ + return (unsigned long)(current_top_of_stack() - + current_stack_pointer) < THREAD_SIZE; +} + #ifdef CONFIG_PARAVIRT #include #else diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 67db4f43309e..42a9c4458f5d 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -141,8 +141,7 @@ void ist_begin_non_atomic(struct pt_regs *regs) * will catch asm bugs and any attempt to use ist_preempt_enable * from double_fault. */ - BUG_ON((unsigned long)(current_top_of_stack() - - current_stack_pointer) >= THREAD_SIZE); + BUG_ON(!on_thread_stack()); preempt_enable_no_resched(); } -- 2.13.6