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Date:   Sun, 28 May 2023 08:57:02 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     mirimmad@outlook.com
Cc:     Immad Mir <mirimmad17@gmail.com>,
        Ivan Orlov <ivan.orlov0322@gmail.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpc: fix debugfs_create_dir error checking
Message-ID: <2023052835-oxidant-doily-404f@gregkh>
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On Sun, May 28, 2023 at 01:16:44PM +0530, mirimmad@outlook.com wrote:
> From: Immad Mir <mirimmad17@gmail.com>
> 
> The debugfs_create_dir returns ERR_PTR incase of an error and the
> correct way of checking it by using the IS_ERR inline function, and
> not the simple null comparision. This patch fixes this.
> 
> Suggested-By: Ivan Orlov <ivan.orlov0322@gmail.com>
> Signed-off-by: Immad Mir <mirimmad17@gmail.com>
> ---
>  arch/powerpc/platforms/powernv/opal-xscom.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c b/arch/powerpc/platforms/powernv/opal-xscom.c
> index 6b4eed2ef..262cd6fac 100644
> --- a/arch/powerpc/platforms/powernv/opal-xscom.c
> +++ b/arch/powerpc/platforms/powernv/opal-xscom.c
> @@ -168,7 +168,7 @@ static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
>  	ent->path.size = strlen((char *)ent->path.data);
> 
>  	dir = debugfs_create_dir(ent->name, root);
> -	if (!dir) {
> +	if (IS_ERR(dir)) {
>  		kfree(ent->path.data);
>  		kfree(ent);
>  		return -1;

Why is this driver caring if debugfs is working or not at all?  It
should just ignore the error and keep moving forward.

And -1 is not a valid error number :(

Have you hit this error on this driver?

thanks,

greg k-h