[ 06/13] of: fdt: fix memory initialization for expanded DT
3.4-stable 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, >_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: Greg Kroah-Hartman
---
drivers/of/fdt.c |2 ++
1 file changed, 2 insertions(+)
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -390,6 +390,8 @@ 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);
--
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[ 06/13] of: fdt: fix memory initialization for expanded DT
3.4-stable review patch. If anyone has any objections, please let me know. -- From: Wladislav Wiebe wladislav...@gmail.com 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 wladislav...@gmail.com Acked-by: Alexander Sverdlin alexander.sverd...@nsn.com Signed-off-by: Rob Herring rob.herr...@calxeda.com Signed-off-by: Greg Kroah-Hartman gre...@linuxfoundation.org --- drivers/of/fdt.c |2 ++ 1 file changed, 2 insertions(+) --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -390,6 +390,8 @@ 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
