Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759154Ab3IHDqo (ORCPT ); Sat, 7 Sep 2013 23:46:44 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56083 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755492Ab3IHDTI (ORCPT ); Sat, 7 Sep 2013 23:19:08 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Alexander Sverdlin" , "Rob Herring" , "Wladislav Wiebe" Date: Sun, 08 Sep 2013 03:52:01 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [084/121] of: fdt: fix memory initialization for expanded DT In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2140 Lines: 56 3.2.51-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Wladislav Wiebe commit 9e40127526e857fa3f29d51e83277204fbdfc6ba upstream. 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 Signed-off-by: Rob Herring Signed-off-by: Ben Hutchings --- drivers/of/fdt.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -389,6 +389,8 @@ static void __unflatten_device_tree(stru 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); -- 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/