From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753900AbdIFViL (ORCPT ); Wed, 6 Sep 2017 17:38:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:50602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753621AbdIFVhQ (ORCPT ); Wed, 6 Sep 2017 17:37:16 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CA36921E93 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@kernel.org Cc: linux-kernel@vger.kernel.org, Borislav Petkov , Brian Gerst , Andrew Cooper , Juergen Gross , Boris Ostrovsky , Kees Cook , Andy Lutomirski Subject: [RFC 15/17] x86/boot/32: Fix cpu_current_top_of_stack initialization at boot Date: Wed, 6 Sep 2017 14:37:00 -0700 Message-Id: <435cba8520a53956b5df9ad9aa1cbe9ab6d4aded.1504733277.git.luto@kernel.org> X-Mailer: git-send-email 2.13.5 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 cpu_current_top_of_stack's initialization forgot about TOP_OF_KERNEL_STACK_PADDING. This bug didn't matter because the idle threads never enter user mode. Signed-off-by: Andy Lutomirski --- arch/x86/kernel/smpboot.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index b474c8de7fba..e6544bac7c51 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -958,8 +958,7 @@ void common_cpu_up(unsigned int cpu, struct task_struct *idle) #ifdef CONFIG_X86_32 /* Stack for startup_32 can be just as for start_secondary onwards */ irq_ctx_init(cpu); - per_cpu(cpu_current_top_of_stack, cpu) = - (unsigned long)task_stack_page(idle) + THREAD_SIZE; + per_cpu(cpu_current_top_of_stack, cpu) = task_top_of_stack(idle); #else initial_gs = per_cpu_offset(cpu); #endif -- 2.13.5