remove_memory_block() calls kfree(mem). I think it shouled be called from
device_release(). So the patch implements memory_block_release()

CC: David Rientjes <rientjes@google.com>
CC: Jiang Liu <redacted>
CC: Len Brown <redacted>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <redacted>
CC: Christoph Lameter <redacted>
Cc: Minchan Kim <redacted>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: KOSAKI Motohiro <redacted>
CC: Wen Congyang <redacted>
Signed-off-by: Yasuaki Ishimatsu <redacted>
---
 drivers/base/memory.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 038be73..1cd3ef3 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c

@@ -109,6 +109,15 @@ bool is_memblk_offline(unsigned long start, unsigned long size)
 }
 EXPORT_SYMBOL(is_memblk_offline);
 
+#define to_memory_block(device) container_of(device, struct memory_block, dev)
+
+static void release_memory_block(struct device *dev)
+{
+	struct memory_block *mem = to_memory_block(dev);
+
+	kfree(mem);
+}
+
 /*
  * register_memory - Setup a sysfs device for a memory block
  */

@@ -119,6 +128,7 @@ int register_memory(struct memory_block *memory)
 
 	memory->dev.bus = &memory_subsys;
 	memory->dev.id = memory->start_section_nr / sections_per_block;
+	memory->dev.release = release_memory_block;
 
 	error = device_register(&memory->dev);
 	return error;

@@ -674,7 +684,6 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section,
 		mem_remove_simple_file(mem, phys_device);
 		mem_remove_simple_file(mem, removable);
 		unregister_memory(mem);
-		kfree(mem);
 	} else
 		kobject_put(&mem->dev.kobj);