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misc: use put_device() instead of kfree()

PATCH In review Arvind Yadav 3 participants 5 messages Mar 12, 2018 – Mar 13, 2018

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#0 lore raw

cover misc: use put_device() instead of kfree()

Never directly free @dev after calling device_register(), even if it returned an error! Always use put_device() to give up the reference initialized.

Arvind Yadav (2):
[PATCH 1/2] misc: mic: Release reference count and memory for VOP device [PATCH 2/2] misc: ocxl: use put_device() instead of device_unregister()

 drivers/misc/mic/bus/vop_bus.c | 6 ++++--
 drivers/misc/ocxl/pci.c        | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)
Signature · 1 line
1.9.1
#1 lore raw

PATCH 1/2 misc: mic: Release reference count and memory for VOP device

Never directly free @dev after calling device_register(), even if it returned an error! Always use put_device() to give up the reference initialized.
Release allocated memory for vop device in vop_release_dev().

---
 drivers/misc/mic/bus/vop_bus.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
drivers/misc/mic/bus/vop_bus.c +4 -2
index fd7f2a6..e5bb9c7 100644
@@ -135,7 +135,9 @@ void vop_unregister_driver(struct vop_driver *driver)
 
 static void vop_release_dev(struct device *d)
 {
-	put_device(d);
+	struct vop_device *dev = dev_to_vop(d);
+
+	kfree(dev);
 }
 
 struct vop_device *
@@ -174,7 +176,7 @@ struct vop_device *
 		goto free_vdev;
 	return vdev;
 free_vdev:
-	kfree(vdev);
+	put_device(&vdev->dev);
 	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(vop_register_device);
Signature · 1 line
1.9.1
#2 lore raw

PATCH 2/2 misc: ocxl: use put_device() instead of device_unregister()

In reply to Arvind Yadav

if device_register() returned an error! Always use put_device() to give up the reference initialized.

---
 drivers/misc/ocxl/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/misc/ocxl/pci.c +1 -1
index 0051d9e..21f4254 100644
@@ -519,7 +519,7 @@ static struct ocxl_fn *init_function(struct pci_dev *dev)
 	rc = device_register(&fn->dev);
 	if (rc) {
 		deconfigure_function(fn);
-		device_unregister(&fn->dev);
+		put_device(&fn->dev);
 		return ERR_PTR(rc);
 	}
 	return fn;
Signature · 1 line
1.9.1
Acked-by on v1 2/2
#3 lore raw

Re: [PATCH 2/2] misc: ocxl: use put_device() instead of device_unregister()

Quoted 4 lines · Arvind Yadav

if device_register() returned an error! Always use put_device() to give up the reference initialized.

This looks right, thanks for picking it up.

Signature · 2 lines
Andrew Donnellan              OzLabs, ADL Canberra
[email protected]  IBM Australia Limited
Acked-by on v1 2/2
#4 lore raw

Re: [PATCH 2/2] misc: ocxl: use put_device() instead of device_unregister()

In reply to Arvind Yadav

Le 12/03/2018 à 12:36, Arvind Yadav a écrit :

Quoted 5 lines

if device_register() returned an error! Always use put_device() to give up the reference initialized.

---

OK, device_unregister() calls put_device() but also other actions that we can skip in this case.

Quoted 17 lines
  drivers/misc/ocxl/pci.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
drivers/misc/ocxl/pci.c +1 -1
index 0051d9e..21f4254 100644
@@ -519,7 +519,7 @@ static struct ocxl_fn *init_function(struct pci_dev *dev)
  	rc = device_register(&fn->dev);
  	if (rc) {
  		deconfigure_function(fn);
-		device_unregister(&fn->dev);
+		put_device(&fn->dev);
  		return ERR_PTR(rc);
  	}
  	return fn;