Re: [PATCH 1/2] pci: rpadlpar: fix leaked device_node references in add/remove paths

[Bjorn Helgaas <helgaas@kernel.org>]

On Fri, Mar 22, 2019 at 01:27:21PM -0500, Tyrel Datwyler wrote:
> The find_dlpar_node() helper returns a device node with its reference
> incremented. Both the add and remove paths use this helper for find the
> appropriate node, but fail to release the reference when done.
> 
> Annotate the find_dlpar_node() helper with a comment about the incremented
> reference count, and call of_node_put() on the obtained device_node in the
> add and remove paths. Also, fixup a reference leak in the find_vio_slot()
> helper where we fail to call of_node_put() on the vdevice node after we
> iterate over its children.
> 
> Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>

Both applied to pci/hotplug for v5.2, thanks!

> ---
>  drivers/pci/hotplug/rpadlpar_core.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
> index e2356a9c7088..182f9e3443ee 100644
> --- a/drivers/pci/hotplug/rpadlpar_core.c
> +++ b/drivers/pci/hotplug/rpadlpar_core.c
> @@ -51,6 +51,7 @@ static struct device_node *find_vio_slot_node(char *drc_name)
>  		if (rc == 0)
>  			break;
>  	}
> +	of_node_put(parent);
>  
>  	return dn;
>  }
> @@ -71,6 +72,7 @@ static struct device_node *find_php_slot_pci_node(char *drc_name,
>  	return np;
>  }
>  
> +/* Returns a device_node with its reference count incremented */
>  static struct device_node *find_dlpar_node(char *drc_name, int *node_type)
>  {
>  	struct device_node *dn;
> @@ -306,6 +308,7 @@ int dlpar_add_slot(char *drc_name)
>  			rc = dlpar_add_phb(drc_name, dn);
>  			break;
>  	}
> +	of_node_put(dn);
>  
>  	printk(KERN_INFO "%s: slot %s added\n", DLPAR_MODULE_NAME, drc_name);
>  exit:
> @@ -439,6 +442,7 @@ int dlpar_remove_slot(char *drc_name)
>  			rc = dlpar_remove_pci_slot(drc_name, dn);
>  			break;
>  	}
> +	of_node_put(dn);
>  	vm_unmap_aliases();
>  
>  	printk(KERN_INFO "%s: slot %s removed\n", DLPAR_MODULE_NAME, drc_name);
> -- 
> 2.12.3
>