Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964889Ab3E2Hel (ORCPT ); Wed, 29 May 2013 03:34:41 -0400 Received: from mail-we0-f172.google.com ([74.125.82.172]:46873 "EHLO mail-we0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935084Ab3E2Hej (ORCPT ); Wed, 29 May 2013 03:34:39 -0400 MIME-Version: 1.0 In-Reply-To: <35FD53F367049845BC99AC72306C23D1610991B85B@CNBJMBX05.corpusers.net> References: <35FD53F367049845BC99AC72306C23D1610991B85B@CNBJMBX05.corpusers.net> Date: Wed, 29 May 2013 09:34:38 +0200 Message-ID: Subject: Re: A bug about system call on ARM From: richard -rw- weinberger To: "Wang, Yalin" Cc: "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3401 Lines: 98 Hi! On Wed, May 29, 2013 at 8:52 AM, Wang, Yalin wrote: > Hi all, > > I am a new comer to this mailing list , > I am happy to join this community . > > I have a bug reported from our android phones which is caused by the system call . > It seems like kernel bugs from my view . Is this a unmodified Linux kernel from kernel.org? In other works, no (half broken) board support package from your hardware vendor? Did you try a more recent kernel? (At least 3.4.47). Maybe your problem is already known and fixed... > Crash in file arch\arm\kernel\ entry-common.S > > /***************************************************************/ > > ENTRY(vector_swi) > sub sp, sp, #S_FRAME_SIZE > stmia sp, {r0 - r12} @ Calling r0 - r12 > ARM( add r8, sp, #S_PC ) > ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr > THUMB( mov r8, sp ) > THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr > mrs r8, spsr @ called from non-FIQ mode, so ok. > str lr, [sp, #S_PC] @ Save calling PC > str r8, [sp, #S_PSR] @ Save CPSR > str r0, [sp, #S_OLD_R0] @ Save OLD_R0 > zero_fp > > /* > * Get the system call number. > */ > > #if defined(CONFIG_OABI_COMPAT) > > /* > * If we have CONFIG_OABI_COMPAT then we need to look at the swi > * value to determine if it is an EABI or an old ABI call. > */ > #ifdef CONFIG_ARM_THUMB > tst r8, #PSR_T_BIT > movne r10, #0 @ no thumb OABI emulation > ldreq r10, [lr, #-4] @ get SWI instruction // crash at this instruction, when get SWI instruction > #else > ldr r10, [lr, #-4] @ get SWI instruction > A710( and ip, r10, #0x0f000000 @ check for SWI ) > A710( teq ip, #0x0f000000 ) > A710( bne .Larm710bug ) > #endif > #ifdef CONFIG_CPU_ENDIAN_BE8 > rev r10, r10 @ little endian instruction > #endif > > /***************************************************************************************************/ > > Then reason why it will crash when get SWI instruction is maybe > This page is clear to aged by kernel, > But this MMU fault happpened in kernel, > So the kernel do_page_fault function will not clear this page to young, > So that will crash . > > It should poll this page to make it present or the fault should be handled by fixup section , > Anyway, this place should not crash by kernel . > > The kernel version I used is 3.4.0 > I have add the kernel log and the call stack recovered by trace32 tools > Pls have a look at it . > > > Thanks . > > > > Sony Mobile Communications > Tel: +86 10 5966 9819 > Phone: 18610323092 > Address: No.16 Guangshun South Street, Chaoyang, Beijing, P.R.C. > > sonymobile.com > > > -- Thanks, //richard -- 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/