From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757740AbcBXEz3 (ORCPT ); Tue, 23 Feb 2016 23:55:29 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:52081 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757204AbcBXEE2 (ORCPT ); Tue, 23 Feb 2016 23:04:28 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anson Huang , Nicolas Pitre , Russell King Subject: [PATCH 3.14 46/70] ARM: 8471/1: need to save/restore arm register(r11) when it is corrupted Date: Tue, 23 Feb 2016 19:33:55 -0800 Message-Id: <20160224033355.592507433@linuxfoundation.org> X-Mailer: git-send-email 2.7.1 In-Reply-To: <20160224033354.061464831@linuxfoundation.org> References: <20160224033354.061464831@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Anson Huang commit fa0708b320f6da4c1104fe56e01b7abf66fd16ad upstream. In cpu_v7_do_suspend routine, r11 is used while it is NOT saved/restored, different compiler may have different usage of ARM general registers, so it may cause issues during calling cpu_v7_do_suspend. We meet kernel fault occurs when using GCC 4.8.3, r11 contains valid value before calling into cpu_v7_do_suspend, but when returned from this routine, r11 is corrupted and lead to kernel fault. Doing save/restore for those corrupted registers is a must in assemble code. Signed-off-by: Anson Huang Reviewed-by: Nicolas Pitre Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/mm/proc-v7.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -95,7 +95,7 @@ ENDPROC(cpu_v7_dcache_clean_area) .equ cpu_v7_suspend_size, 4 * 9 #ifdef CONFIG_ARM_CPU_SUSPEND ENTRY(cpu_v7_do_suspend) - stmfd sp!, {r4 - r10, lr} + stmfd sp!, {r4 - r11, lr} mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID mrc p15, 0, r5, c13, c0, 3 @ User r/o thread ID stmia r0!, {r4 - r5} @@ -112,7 +112,7 @@ ENTRY(cpu_v7_do_suspend) mrc p15, 0, r9, c1, c0, 1 @ Auxiliary control register mrc p15, 0, r10, c1, c0, 2 @ Co-processor access control stmia r0, {r5 - r11} - ldmfd sp!, {r4 - r10, pc} + ldmfd sp!, {r4 - r11, pc} ENDPROC(cpu_v7_do_suspend) ENTRY(cpu_v7_do_resume)