Messages in this thread | | | Date | Tue, 22 Jun 2021 16:36:30 +0200 | From | Dominik Brodowski <> | Subject | Re: v5.13-rcX regression - NULL pointer dereference - MFD and software node API |
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Am Tue, Jun 22, 2021 at 05:10:44PM +0300 schrieb Heikki Krogerus: > On Tue, Jun 22, 2021 at 11:09:58AM +0300, Heikki Krogerus wrote: > > On Mon, Jun 21, 2021 at 05:31:50PM +0200, Dominik Brodowski wrote: > > > Am Mon, Jun 21, 2021 at 01:37:59PM +0300 schrieb Heikki Krogerus: > > > > On Mon, Jun 21, 2021 at 01:00:06PM +0300, Andy Shevchenko wrote: > > > > > Can you, please, attach this to the bug report? > > > > > > > > > > Long story here is that the device creation fails but we already have added > > > > > swnode to it. Meanwhile, device itself is not completely instantiated (yet) > > > > > and dev_name(dev) is NULL. The software_node_notify() is called with such > > > > > device and Oopses in the following line > > > > > > > > > > sysfs_remove_link(&swnode->kobj, dev_name(dev)); > > > > > > > > > > My patch fixes another issue that might happen before this and in the code > > > > > that retrieves swnode itself in the device_remove_software_node(). > > > > > > > > > > Of course my patch won't fix this issue. > > > > > > > > > > I have heard that Heikki is looking how to fix the issue in your case and > > > > > potentially in any other cases where device_add_software_node() is called > > > > > against not formed object instance. > > > > > > > > Dominik, can you test the attached patch to confirm if this really is > > > > the case. > > > > > > With this patch applied, the panic disappears. > > > > Thanks Dominik. I'll clean it and send it out today. > > Before I send the patch to Rafael and Greg, can you confirm that the > appropriate API (device_is_registered()) also works? I'm attaching > patch that should be the final version (if it works).
Heikki, that works perfectly. Many thanks, especially for the speedy development of the bugfix!
Best, Dominik
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