linux-kernel - Re: [PATCH 1/6] software node: Provide replacement for device_add

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 2 Feb 2021 17:01:02 +0200
From:   Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To:     "Rafael J. Wysocki" <rafael@...nel.org>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Felipe Balbi <balbi@...nel.org>,
        Mathias Nyman <mathias.nyman@...el.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        "open list:ULTRA-WIDEBAND (UWB) SUBSYSTEM:" 
        <linux-usb@...r.kernel.org>
Subject: Re: [PATCH 1/6] software node: Provide replacement for
 device_add_properties()

Hi Rafael,

On Tue, Feb 02, 2021 at 03:44:05PM +0100, Rafael J. Wysocki wrote:
> > +/**
> > + * device_create_managed_software_node - Create a software node for a device
> > + * @dev: The device the software node is assigned to.
> > + * @properties: Device properties for the software node.
> > + * @parent: Parent of the software node.
> > + *
> > + * Creates a software node as a managed resource for @dev, which means the
> > + * lifetime of the newly created software node is tied to the lifetime of @dev.
> > + * Software nodes created with this function should not be reused or shared
> > + * because of that. The function takes a deep copy of @properties for the
> > + * software node.
> > + *
> > + * Since the new software node is assigned directly to @dev, and since it should
> > + * not be shared, it is not returned to the caller. The function returns 0 on
> > + * success, and errno in case of an error.
> > + */
> > +int device_create_managed_software_node(struct device *dev,
> > +                                       const struct property_entry *properties,
> > +                                       const struct software_node *parent)
> > +{
> > +       struct fwnode_handle *p = software_node_fwnode(parent);
> > +       struct fwnode_handle *fwnode;
> > +
> > +       if (parent && !p)
> > +               return -EINVAL;
> > +
> > +       fwnode = fwnode_create_software_node(properties, p);
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To answer your question below: here.

> > +       if (IS_ERR(fwnode))
> > +               return PTR_ERR(fwnode);
> > +
> > +       to_swnode(fwnode)->managed = true;
> > +       set_secondary_fwnode(dev, fwnode);
> > +
> > +       return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(device_create_managed_software_node);
> > +
> >  int software_node_notify(struct device *dev, unsigned long action)
> >  {
> >         struct swnode *swnode;
> > @@ -1073,6 +1111,11 @@ int software_node_notify(struct device *dev, unsigned long action)
> >                 sysfs_remove_link(&swnode->kobj, dev_name(dev));
> >                 sysfs_remove_link(&dev->kobj, "software_node");
> >                 kobject_put(&swnode->kobj);
> > +
> > +               if (swnode->managed) {
> > +                       set_secondary_fwnode(dev, NULL);
> > +                       kobject_put(&swnode->kobj);
> 
> Where does the corresponding kobject_get() get called?

So in function fwnode_create_software_node() we use
kobject_init_and_add().


thanks,

-- 
heikki