From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20130911042929.513749552@goodmis.org> Date: Wed, 11 Sep 2013 00:30:51 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wladislav Wiebe , Alexander Sverdlin , Rob Herring Subject: [224/251] of: fdt: fix memory initialization for expanded DT References: <20130911042707.738353451@goodmis.org> Content-Disposition: inline; filename=0224-of-fdt-fix-memory-initialization-for-expanded-DT.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.6.11.9-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Wladislav Wiebe [ Upstream commit 9e40127526e857fa3f29d51e83277204fbdfc6ba ] 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 Cc: stable@vger.kernel.org Signed-off-by: Rob Herring Signed-off-by: Steven Rostedt --- drivers/of/fdt.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 91a375f..17fad3b 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -390,6 +390,8 @@ 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); -- 1.7.10.4