linux-kernel - Re: [PATCH] kernel/power/energy_model.c: fix memory leak with using debugfs

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Message-ID: <CAJZ5v0ikyjgKfrnEk=yiK-KHas8QEC0-O_mdRCMvkeKS+uoovw@mail.gmail.com>
Date:   Thu, 9 Feb 2023 20:37:10 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-pm@...r.kernel.org, "Rafael J. Wysocki" <rafael@...nel.org>,
        Pavel Machek <pavel@....cz>, Len Brown <len.brown@...el.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] kernel/power/energy_model.c: fix memory leak with using debugfs_lookup()

On Thu, Feb 2, 2023 at 4:15 PM Greg Kroah-Hartman
<gregkh@...uxfoundation.org> wrote:
>
> When calling debugfs_lookup() the result must have dput() called on it,
> otherwise the memory will leak over time.  To make things simpler, just
> call debugfs_lookup_and_remove() instead which handles all of the logic
> at once.
>
> Cc: "Rafael J. Wysocki" <rafael@...nel.org>
> Cc: Pavel Machek <pavel@....cz>
> Cc: Len Brown <len.brown@...el.com>
> Cc: linux-pm@...r.kernel.org
> Cc: linux-kernel@...r.kernel.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> ---
>  kernel/power/energy_model.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
> index f82111837b8d..7b44f5b89fa1 100644
> --- a/kernel/power/energy_model.c
> +++ b/kernel/power/energy_model.c
> @@ -87,10 +87,7 @@ static void em_debug_create_pd(struct device *dev)
>
>  static void em_debug_remove_pd(struct device *dev)
>  {
> -       struct dentry *debug_dir;
> -
> -       debug_dir = debugfs_lookup(dev_name(dev), rootdir);
> -       debugfs_remove_recursive(debug_dir);
> +       debugfs_lookup_and_remove(dev_name(dev), rootdir);
>  }
>
>  static int __init em_debug_init(void)
> --

Applied as 6.3 material, thanks!