Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756079Ab3HPMag (ORCPT ); Fri, 16 Aug 2013 08:30:36 -0400 Received: from demumfd001.nsn-inter.net ([93.183.12.32]:13888 "EHLO demumfd001.nsn-inter.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751149Ab3HPMad (ORCPT ); Fri, 16 Aug 2013 08:30:33 -0400 Message-ID: <520E1B62.1060501@nsn.com> Date: Fri, 16 Aug 2013 14:30:26 +0200 From: Alexander Sverdlin User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: ext Wladislav Wiebe CC: grant.likely@linaro.org, rob.herring@calxeda.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] of: fdt: fix memory initialization for expanded DT References: <5208C04A.5000303@gmail.com> In-Reply-To: <5208C04A.5000303@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-purgate-type: clean X-purgate-Ad: Categorized by eleven eXpurgate (R) http://www.eleven.de X-purgate: clean X-purgate: This mail is considered clean (visit http://www.eleven.de for further information) X-purgate-size: 1944 X-purgate-ID: 151667::1376656227-00003561-91DB344C/0-0/0-0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2137 Lines: 57 Hi! On 08/12/2013 01:00 PM, ext Wladislav Wiebe wrote: > Already existing property flags are filled wrong for properties created from > initial FDT. This could cause problems if this DYNAMIC device-tree functions > are used later, i.e. properties are attached/detached/replaced. Simply dumping > flags from the running system show, that some initial static (not allocated via > kzmalloc()) nodes are marked as dynamic. > > I putted some debug extensions to property_proc_show(..) : > .. > + if (OF_IS_DYNAMIC(pp)) > + pr_err("DEBUG: xxx : OF_IS_DYNAMIC\n"); > + if (OF_IS_DETACHED(pp)) > + pr_err("DEBUG: xxx : OF_IS_DETACHED\n"); > > when you operate on the nodes (e.g.: ~$ cat /proc/device-tree/*some_node*) you > will see that those flags are filled wrong, basically in most cases it will dump > a DYNAMIC or DETACHED status, which is in not true. > (BTW. this OF_IS_DETACHED is a own define for debug purposes which which just > make a test_bit(OF_DETACHED, &x->_flags) > > If nodes are dynamic kernel is allowed to kfree() them. But it will crash > attempting to do so on the nodes from FDT -- they are not allocated via > kzmalloc(). > > Signed-off-by: Wladislav Wiebe Acked-by: Alexander Sverdlin > --- > drivers/of/fdt.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 6bb7cf2..b10ba00 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -392,6 +392,8 @@ static void __unflatten_device_tree(struct boot_param_header *blob, > mem = (unsigned long) > dt_alloc(size + 4, __alignof__(struct device_node)); > > + memset((void *)mem, 0, size); > + > ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef); > > pr_debug(" unflattening %lx...\n", mem); > -- Best regards, Alexander Sverdlin. -- 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/