[PATCH] mtd: physmap_of: Fix map name when "linux, mtd-name" is absent

[Pawel Moll]

Commit d68cbdd4fb04d2b756ad53c22f36943167b16340 "mtd: physmap_of:
allow to specify the mtd name for retro compatiblity" introduced
a "linux,mtd-name" property to override map names, but when
this property is absent (so of_property_read_string() returns
value != 0) an uninitialized value is used (as mtd_name is not
set). This may lead to kernel oopses when the name is
derefernced, eg:

Unable to handle kernel NULL pointer dereference at virtual address 00000001
pgd = 80004000
[00000001] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 3    Not tainted  (3.8.0-rc5+ #644)
PC is at strcmp+0x4/0x30
LR is at parse_cmdline_partitions+0x54/0x2f8

Fixed by initializing the variable to NULL.

Signed-off-by: Pawel Moll <pawel.moll at arm.com>
---
 drivers/mtd/maps/physmap_of.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index 67cc73c..7901d72 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -170,7 +170,7 @@ static int of_flash_probe(struct platform_device *dev)
 	resource_size_t res_size;
 	struct mtd_part_parser_data ppdata;
 	bool map_indirect;
-	const char *mtd_name;
+	const char *mtd_name = NULL;
 
 	match = of_match_device(of_flash_match, &dev->dev);
 	if (!match)
-- 
1.7.10.4