Re: [PATCH] x86/platform/intel/iosf_mbi: Fix error handling in iosf_mbi_init()

[Yuan Can <yuancan@xxxxxxxxxx>]

在 2022/11/15 16:26, Andy Shevchenko 写道:
> On Tue, Nov 15, 2022 at 9:38 AM Yuan Can <yuancan@xxxxxxxxxx> wrote:
> > A problem about modprobe iosf_mbi failed is triggered with the following
> > log given:
> >
> >   debugfs: Directory 'iosf_sb' with parent '/' already present!
> >
> > The reason is that iosf_mbi_init() returns pci_register_driver()
> > directly without checking its return value, if pci_register_driver()
> > failed, it returns without removing debugfs, resulting the debugfs of
> > iosf_sb can never be created later.
> >
> >   iosf_mbi_init()
> >     iosf_mbi_dbg_init() # create debugfs
> >     pci_register_driver()
> >       driver_register()
> >         bus_add_driver()
> >           priv = kzalloc(...) # OOM happened
> >     # return without remove debugfs and destroy workqueue
> >
> > Fix by remove debugfs and iosf_mbi_pm_qos when pci_register_driver()
> removing
>
> > returns error.
> >   static int __init iosf_mbi_init(void)
> >   {
> > +       int ret;
> > +
> >          iosf_debugfs_init();
> >
> >          cpu_latency_qos_add_request(&iosf_mbi_pm_qos, PM_QOS_DEFAULT_VALUE);
> >
> > -       return pci_register_driver(&iosf_mbi_pci_driver);
> > +       ret = pci_register_driver(&iosf_mbi_pci_driver);
> > +       if (ret) {
> > +               cpu_latency_qos_remove_request(&iosf_mbi_pm_qos);
> > +               iosf_debugfs_remove();
> > +       }
> > +
> > +       return ret;
> >   }
> Can we rewrite it as
>
>    if (ret)
>      goto err_remove;
>
>    return 0;
>
> err_remove:
>    ...
>    return ret;
>
> ?
Thanks for these suggestions! will be changed in the next version.

--
Best regards,
Yuan Can