[1/7,v2] fix memory leak when memory device is unbound from the module acpi_memhotplug

Commit Message

Wen Congyang July 11, 2012, 7:47 a.m. UTC

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

Signed-off-by: Wen Congyang <[e-mail]>
---
 drivers/acpi/acpi_memhotplug.c |   31 +++++++++++++++++++++----------
 1 files changed, 21 insertions(+), 10 deletions(-)

Comments

Andrew Morton July 11, 2012, 9:55 p.m. UTC | #1

On Wed, 11 Jul 2012 15:47:02 +0800
Wen Congyang <[e-mail]> wrote:

> To: [e-mail]

I'm still not sure if that email address works?  I've been cc'ing
[e-mail] lately as well.  

There are some pretty serious-looking bugfixes in this series.


I merged your patches into my tree to get them a bit of testing. 
Please note that I renamed them all so their titles reflect the
subsystem which they are patching.  Documentation/SubmittingPatches
section 15 goes into details on this convention.

Having done that rename, it becomes obvious that patches 1-6 are acpi
memhotplug changes, but the seventh patch is a fix against core MM
code.  I've sent that patch to Linus earlier today.
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Patch

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index d985713..fe699ec 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -125,12 +125,20 @@  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;
+
+	list_for_each_entry_safe(info, n, &mem_device->res_list, list)
+		kfree(info);
+	INIT_LIST_HEAD(&mem_device->res_list);
+}
+
 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;
@@ -138,9 +146,7 @@  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)) {
-		list_for_each_entry_safe(info, n, &mem_device->res_list, list)
-			kfree(info);
-		INIT_LIST_HEAD(&mem_device->res_list);
+		acpi_memory_free_device_resources(mem_device);
 		return -EINVAL;
 	}
 
@@ -399,6 +405,15 @@  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;
@@ -451,14 +466,10 @@  static int acpi_memory_device_add(struct acpi_device *device)
 
 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 {
-	struct acpi_memory_device *mem_device = NULL;
-
-
 	if (!device || !acpi_driver_data(device))
 		return -EINVAL;
 
-	mem_device = acpi_driver_data(device);
-	kfree(mem_device);
+	acpi_memory_device_free(acpi_driver_data(device));
 
 	return 0;
 }