Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757650AbYCCOpl (ORCPT ); Mon, 3 Mar 2008 09:45:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754041AbYCCOny (ORCPT ); Mon, 3 Mar 2008 09:43:54 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:37164 "EHLO gprs189-60.eurotel.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753939AbYCCOnx (ORCPT ); Mon, 3 Mar 2008 09:43:53 -0500 Date: Mon, 3 Mar 2008 13:17:35 +0100 From: Pavel Machek To: "Klaus S. Madsen" , Suspend-devel list Cc: Ingo Molnar , "H. Peter Anvin" , LKML , "Rafael J. Wysocki" , Thomas Gleixner Subject: Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending Message-ID: <20080303121735.GE28369@elf.ucw.cz> References: <20080228150444.GG17932@hjernemadsen.org> <47C6F4F9.90700@zytor.com> <20080228192404.GH17932@hjernemadsen.org> <47C70C01.4020605@zytor.com> <20080228194920.GJ17932@hjernemadsen.org> <47C739A6.5020608@zytor.com> <20080229070028.GK17932@hjernemadsen.org> <47C873AA.6040305@zytor.com> <20080229212654.GL27212@elte.hu> <20080301094525.GQ17932@hjernemadsen.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080301094525.GQ17932@hjernemadsen.org> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2162 Lines: 48 Hi! > > > Klaus S. Madsen wrote: > > >> open("/dev/mem", O_RDWR) = 5 > > >> mmap2(NULL, 1282, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED|MAP_FIXED, 5, 0) = 0 > > >> mmap2(0xa0000, 393216, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 5, 0xa0) = 0xa0000 > > > ^^^^^^^^^^^^^^^^^^^^ > > >> close(5) = 0 > > >> ioperm(0, 0x400, 0x1) = 0 > > >> iopl(0x3) = 0 > > >> access("/sys/bus/pci", R_OK) = 0 > > >> write(1, "Calling get_mode\n", 17) = 17 > > >> vm86(0x1, 0xb7f14ccc, 0xb7f14830, 0xc000, 0x18b6 > > >> --- SIGSEGV (Segmentation fault) @ 0 (0) --- > > >> +++ killed by SIGSEGV (core dumped) +++ > > > > > > This is the VGA BIOS being mapped, it's mapped PROT_READ|PROT_WRITE, but > > > no PROT_EXEC; if the kernel is NX-capable it *should* segfault trying to > > > execute out of this area, which is exactly what will happen when vm86 > > > executes INT 10h. > > > > > > If we can find that mmap() in the s2ram source code and add PROT_EXEC > > > to it, it would be interesting. > > > > Klaus, could you send your .config as well? Lets make sure that NX is > > even relevant in this context. > Allright. The mmap in question is in the x86-common.c file in libx86, > and adding PROT_EXEC to it solves the problem. Ok, sw should probably fix that in s2ram... can you mail a patch to me, and suspend-devel? > I have attached my .config. > > The only thing I don't understand is why this is suddenly a problem with > 2.6.25, and not with 2.6.24? Is there a bug in 2.6.24 and previously > that allows real-mode execution of non-executable pages? It is strange indeed... Should it be traced as an regression? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/