Date:   Wed, 12 Jan 2022 07:48:53 +0900
From:   William Breathitt Gray <vilhelm.gray@gmail.com>
To:     Dan Carpenter <dan.carpenter@oracle.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel-janitors@vger.kernel.org
Subject: Re: [PATCH v2] counter: fix an IS_ERR() vs NULL bug
Message-ID: <Yd4JVSTUcFVFNhaJ@shinobu>
References: <20220111173243.GA2192@kili>
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On Tue, Jan 11, 2022 at 08:32:43PM +0300, Dan Carpenter wrote:
> There are 8 callers for devm_counter_alloc() and they all check for NULL
> instead of error pointers.  I think NULL is the better thing to return
> for allocation functions so update counter_alloc() and devm_counter_alloc=
()
> to return NULL instead of error pointers.
>=20
> Fixes: c18e2760308e ("counter: Provide alternative counter registration f=
unctions")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

> ---
> v2: make additional style changes
>=20
>  drivers/counter/counter-core.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
>=20
> diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-cor=
e.c
> index 7e0957eea094..869894b74741 100644
> --- a/drivers/counter/counter-core.c
> +++ b/drivers/counter/counter-core.c
> @@ -90,10 +90,8 @@ struct counter_device *counter_alloc(size_t sizeof_pri=
v)
>  	int err;
> =20
>  	ch =3D kzalloc(sizeof(*ch) + sizeof_priv, GFP_KERNEL);
> -	if (!ch) {
> -		err =3D -ENOMEM;
> -		goto err_alloc_ch;
> -	}
> +	if (!ch)
> +		return NULL;
> =20
>  	counter =3D &ch->counter;
>  	dev =3D &counter->dev;
> @@ -123,9 +121,8 @@ struct counter_device *counter_alloc(size_t sizeof_pr=
iv)
>  err_ida_alloc:
> =20
>  	kfree(ch);
> -err_alloc_ch:
> =20
> -	return ERR_PTR(err);
> +	return NULL;
>  }
>  EXPORT_SYMBOL_GPL(counter_alloc);
> =20
> @@ -208,12 +205,12 @@ struct counter_device *devm_counter_alloc(struct de=
vice *dev, size_t sizeof_priv
>  	int err;
> =20
>  	counter =3D counter_alloc(sizeof_priv);
> -	if (IS_ERR(counter))
> -		return counter;
> +	if (!counter)
> +		return NULL;
> =20
>  	err =3D devm_add_action_or_reset(dev, devm_counter_put, counter);
>  	if (err < 0)
> -		return ERR_PTR(err);
> +		return NULL;
> =20
>  	return counter;
>  }
> --=20
> 2.20.1
>=20

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