[Patch v4 3/7] acpi_memhotplug.c: fix memory leak when memory device is unbound from the module acpi_memhotplug

From: Wen Congyang
Date: Thu Nov 08 2012 - 06:00:26 EST


We allocate memory to store acpi_memory_info, so we should free it before
freeing mem_device.

CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
CC: Rafael J. Wysocki <rjw@xxxxxxx>
CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
drivers/acpi/acpi_memhotplug.c | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index e573e87..5e5ac80 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -131,12 +131,22 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context)
return AE_OK;
}

+static void
+acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
+{
+ struct acpi_memory_info *info, *n;
+
+ mutex_lock(&mem_device->list_lock);
+ list_for_each_entry_safe(info, n, &mem_device->res_list, list)
+ kfree(info);
+ INIT_LIST_HEAD(&mem_device->res_list);
+ mutex_unlock(&mem_device->list_lock);
+}
+
static int
acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
{
acpi_status status;
- struct acpi_memory_info *info, *n;
-

if (!list_empty(&mem_device->res_list))
return 0;
@@ -144,11 +154,7 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
acpi_memory_get_resource, mem_device);
if (ACPI_FAILURE(status)) {
- mutex_lock(&mem_device->list_lock);
- list_for_each_entry_safe(info, n, &mem_device->res_list, list)
- kfree(info);
- INIT_LIST_HEAD(&mem_device->res_list);
- mutex_unlock(&mem_device->list_lock);
+ acpi_memory_free_device_resources(mem_device);
return -EINVAL;
}

@@ -447,6 +453,15 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
return;
}

+static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
+{
+ if (!mem_device)
+ return;
+
+ acpi_memory_free_device_resources(mem_device);
+ kfree(mem_device);
+}
+
static int acpi_memory_device_add(struct acpi_device *device)
{
int result;
@@ -512,7 +527,7 @@ static int acpi_memory_device_remove(struct acpi_device *device, int type)
if (result)
return result;

- kfree(mem_device);
+ acpi_memory_device_free(mem_device);

return 0;
}
--
1.8.0

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