From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wladislav Wiebe Subject: Re: seq_file: procfs: kmalloc_slab WARNING Date: Fri, 30 Aug 2013 09:10:51 +0200 Message-ID: <5220457B.60200@gmail.com> References: <5200F97F.50204@gmail.com> <20130829145450.5f8b30326484e7098dcf6e08@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org To: Andrew Morton Return-path: Received: from mail-la0-f42.google.com ([209.85.215.42]:35703 "EHLO mail-la0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752002Ab3H3HMd (ORCPT ); Fri, 30 Aug 2013 03:12:33 -0400 Received: by mail-la0-f42.google.com with SMTP id ep20so1218452lab.15 for ; Fri, 30 Aug 2013 00:12:32 -0700 (PDT) In-Reply-To: <20130829145450.5f8b30326484e7098dcf6e08@linux-foundation.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hi Andrew, On 29/08/13 23:54, Andrew Morton wrote: > On Tue, 06 Aug 2013 15:26:23 +0200 Wladislav Wiebe wrote: > > [..] > kmalloc_large() only exists in slub, so this will break slab and slob > builds. > > Did you try adding __GFP_NOWARN? That's appropriate in this case. > Thanks for the reply, I already committed the fix for the real problem in DT: 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 --- 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); -- 1.7.1