Re: [PATCH v2] PM: domains: Ensure genpd_debugfs_dir exists before remove

[Greg Kroah-Hartman]

On Wed, Jul 06, 2022 at 01:16:49AM +0800, Hsin-Yi Wang wrote:
> Both genpd_debug_add() and genpd_debug_remove() may be called
> indirectly by other drivers while genpd_debugfs_dir is not yet
> set. For example, drivers can call pm_genpd_init() in probe or
> pm_genpd_init() in probe fail/cleanup path:
> 
> pm_genpd_init()
>  --> genpd_debug_add()
> 
> pm_genpd_remove()
>  --> genpd_remove()
>    --> genpd_debug_remove()
> 
> At this time, genpd_debug_init() may not yet be called.
> 
> genpd_debug_add() checks that if genpd_debugfs_dir is NULL, it
> will return directly. Make sure this is also checked
> in pm_genpd_remove(), otherwise components under debugfs root
> which has the same name as other components under pm_genpd may
> be accidentally removed, since NULL represents debugfs root.
> 
> Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains")
> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> ---
> v1->v2: Add more context in commit message

Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>