Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751067Ab3IXG3c (ORCPT ); Tue, 24 Sep 2013 02:29:32 -0400 Received: from mail-oa0-f44.google.com ([209.85.219.44]:50347 "EHLO mail-oa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750808Ab3IXG3b (ORCPT ); Tue, 24 Sep 2013 02:29:31 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Tue, 24 Sep 2013 11:59:30 +0530 Message-ID: Subject: Re: [Query] Stack Overflow in "arch/arm/kernel/unwind.c" while unwinding frame From: Anurag Aggarwal To: Jean Pihet Cc: linux@arm.linux.org.uk, "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.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: 2068 Lines: 67 Hi Jean, I don't think that it is related to the warning that you have suggested On Tue, Sep 24, 2013 at 11:58 AM, Jean Pihet wrote: > Hi, > > Adding Russell and l.a.k ML. > > Another question: is this linked to the following build warning? > CC arch/arm/kernel/return_address.o > arch/arm/kernel/return_address.c:63:2: warning: #warning "TODO: > return_address should use unwind tables" > > Regards, > Jean > > On 24 September 2013 07:23, Anurag Aggarwal wrote: >> Hi All, >> >> While executing unwind backtrace instructions in ARM, in the function >> unwind_exec_insn() >> there are chances that SP overflows from stack. >> >> >> For example while executing instruction with opcode 0xAE, vsp can go >> beyond stack to area that has not been allocated till now. >> >> unsigned long *vsp = (unsigned long *)ctrl->vrs[SP]; >> int reg; >> >> /* pop R4-R[4+bbb] */ >> for (reg = 4; reg <= 4 + (insn & 7); reg++) >> ctrl->vrs[reg] = *vsp++; >> >> The above scenario can happen while executing any of the unwind instruction. >> >> One of the ways to fix the problem is to check for vsp with stack >> limits before we increment it, but doing it for all the instructions >> seems a little bad. >> >> I just want to know that if anyone has faced the problem before >> >> I am working on Linux kernel for Android phones and I saw one case >> when this happened. >> >> I am new to Linux Kernel so not sure if this is the right place to ask >> the question. >> >> >> -- >> Anurag Aggarwal >> -- >> 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/ -- Anurag Aggarwal -- 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/