[PATCH] regmap: debugfs: fix a memory leak when calling regmap_attach_dev

[Xiaolei Wang]

This should be caused by
commit <9b947a13e7f6> ("<regmap: use debugfs even when no device>")

After initializing the regmap through
syscon_regmap_lookup_by_compatible, then regmap_attach_dev to the
device, because the debugfs_name has been allocated, there is no need to
redistribute it again

unreferenced object 0xd8399b80 (size 64):
  comm "swapper/0", pid 1, jiffies 4294937641 (age 278.590s)
  hex dump (first 32 bytes):
        64 75 6d 6d 79 2d 69 6f 6d 75 78 63 2d 67 70 72
dummy-iomuxc-gpr
        40 32 30 65 34 30 30 30 00 7f 52 5b d8 7e 42 69
@20e4000..R[.~Bi
  backtrace:
        [<ca384d6f>] kasprintf+0x2c/0x54
        [<6ad3bbc2>] regmap_debugfs_init+0xdc/0x2fc
        [<bc4181da>] __regmap_init+0xc38/0xd88
        [<1f7e0609>] of_syscon_register+0x168/0x294
        [<735e8766>] device_node_get_regmap+0x6c/0x98
        [<d96c8982>] imx6ul_init_machine+0x20/0x88
        [<0456565b>] customize_machine+0x1c/0x30
        [<d07393d8>] do_one_initcall+0x80/0x3ac
        [<7e584867>] kernel_init_freeable+0x170/0x1f0
        [<80074741>] kernel_init+0x8/0x120
        [<285d6f28>] ret_from_fork+0x14/0x20
        [<00000000>] 0x0

Signed-off-by: Xiaolei Wang <xiaolei.w...@windriver.com>
---
 drivers/base/regmap/regmap-debugfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/regmap/regmap-debugfs.c 
b/drivers/base/regmap/regmap-debugfs.c
index 8dfac7f3ed7a..271142981f98 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -582,8 +582,10 @@ void regmap_debugfs_init(struct regmap *map)
                devname = dev_name(map->dev);
 
        if (name) {
-               map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
+               if (!map->debugfs_name) {
+                       map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
                                              devname, name);
+               }
                name = map->debugfs_name;
        } else {
                name = devname;
-- 
2.25.1