On 2018-09-25 12:31 p.m., Bart Van Assche wrote:

On Tue, 2018-09-25 at 12:15 -0600, Logan Gunthorpe wrote:

quoted

On 2018-09-25 11:29 a.m., Bart Van Assche wrote:

quoted

On Tue, 2018-09-25 at 10:22 -0600, Logan Gunthorpe wrote:

quoted

@@ -83,9 +132,14 @@ static int pci_p2pdma_setup(struct pci_dev *pdev)
 
 	pdev->p2pdma = p2p;
 
+	error = sysfs_create_group(&pdev->dev.kobj, &p2pmem_group);
+	if (error)
+		goto out_pool_destroy;
+
 	return 0;
 
 out_pool_destroy:
+	pdev->p2pdma = NULL;
 	gen_pool_destroy(p2p->pool);
 out:
 	devm_kfree(&pdev->dev, p2p);

This doesn't look right to me. Shouldn't devm_remove_action() be called instead
of devm_kfree() if sysfs_create_group() fails?

That makes no sense to me. We are reversing a devm_kzalloc() not a
custom action....

In case what I wrote was not clear: both devm_kzalloc() and
devm_add_action_or_reset() have to be reversed if sysfs_create_group() fails.
devm_add_action_or_reset() calls devres_add(). The latter function adds an
element to the dev->devres_head list. So I think that only calling devm_kfree()
if sysfs_create_group() fails will lead to corruption of the dev->devres_head
list.

I don't see how it would corrupt the list. devres_remove() uses
list_del_init() which doesn't require that you only remove the tail from
the list... The way I read the code, you can remove any devm action at
any time.

Logan