From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751832AbdIVDPb (ORCPT ); Thu, 21 Sep 2017 23:15:31 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:57898 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751780AbdIVDPa (ORCPT ); Thu, 21 Sep 2017 23:15:30 -0400 X-UUID: 70cb9e1d885c4ed2a606918da336fd95-20170922 From: Ji Zhang To: Russell King , Matthias Brugger CC: , , , , Ji Zhang Subject: [PATCH] arm: fix text section corruption Date: Fri, 22 Sep 2017 11:15:19 +0800 Message-ID: <1506050119-2670-1-git-send-email-ji.zhang@mediatek.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When CONFIG_CPU_SW_DOMAIN_PAN is enabled, there are 9 registers being pushed into stack in save_regs, but in fixup it still consider there are 8 registers in stack, which is the case of CONFIG_CPU_SW_DOMAIN_PAN disabled. When fixup being executed, -EFAULT will be written to the text section. In fixup: mov r4, #-EFAULT /* * When CONFIG_CPU_SW_DOMAIN_PAN enabled, r5 will load the value stored by * lr in save_regs, which is the address of instruction in text section. */ ldr r5, [sp,#8*4] @err_ptr /* * This will write -EFAULT(0xfffffff2) to r5, which points to text section * now, and when function returns, it will use 0xfffffff2 as an * instruction, then undefined instruction occurs. */ str r4, [r5] Signed-off-by: Ji Zhang --- arch/arm/lib/csumpartialcopyuser.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/lib/csumpartialcopyuser.S b/arch/arm/lib/csumpartialcopyuser.S index 1712f13..b83fdc0 100644 --- a/arch/arm/lib/csumpartialcopyuser.S +++ b/arch/arm/lib/csumpartialcopyuser.S @@ -85,7 +85,11 @@ .pushsection .text.fixup,"ax" .align 4 9001: mov r4, #-EFAULT +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + ldr r5, [sp, #9*4] @ *err_ptr +#else ldr r5, [sp, #8*4] @ *err_ptr +#endif str r4, [r5] ldmia sp, {r1, r2} @ retrieve dst, len add r2, r2, r1 -- 1.9.1