From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VH7BY-0004mm-HO for barebox@lists.infradead.org; Wed, 04 Sep 2013 07:07:29 +0000 Date: Wed, 4 Sep 2013 09:07:04 +0200 From: Sascha Hauer Message-ID: <20130904070704.GI30088@pengutronix.de> References: <1377964462-10387-1-git-send-email-plagnioj@jcrosoft.com> <20130902090523.GT30088@pengutronix.de> <20130902102406.GK19197@ns203013.ovh.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20130902102406.GK19197@ns203013.ovh.net> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 1/1] arm: mmu: catch NULL pointer dereferences To: Jean-Christophe PLAGNIOL-VILLARD Cc: barebox@lists.infradead.org On Mon, Sep 02, 2013 at 12:24:06PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote: > On 11:05 Mon 02 Sep , Sascha Hauer wrote: > > On Sat, Aug 31, 2013 at 05:54:22PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote: > > > For high vectors if memory start at 0x0. We have to > > > live without being able to catch NULL pointer dereferences. > > > > > Why not add the check to vectors_init() instead of passing this as > > argument? > > > > I must say I'm not entirely happy with this approach. Being able to > > catch NULL pointer derefs is really a good thing. When exactly does the > > faulting zero SDRAM page become a problem for you? obviously something > > like > > > > cp /somehing /dev/ram0 > > > > does not work. Some care must probably be taken when setting up the > > kernel parameters. Are these the problems or is there something else? > yes it's get issue with uImage that get data load there :( > > as I can not control the load addr from uImage :( > > and on ux5x0 and arm board I have ddr starting at 0x0 Maybe we should add some hook which dynamically enables/disables the zero page. The bootm code could then disable it. Anyway, for now we can also apply the current patch, but please move the is_start_zero test to vectors_init(). Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox