Message-ID: <1504197650.2786.38.camel@perches.com>
Subject: Re: [PATCH 4.9 01/12] p54: memset(0) whole array
From: Joe Perches <joe@perches.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org, Jiri Slaby <jslaby@suse.cz>,
        Christian Lamparter <chunkeey@googlemail.com>,
        Kalle Valo <kvalo@codeaurora.org>
Date: Thu, 31 Aug 2017 09:40:50 -0700
In-Reply-To: <20170831154238.982008528@linuxfoundation.org>
References: <20170831154238.914795784@linuxfoundation.org>
         <20170831154238.982008528@linuxfoundation.org>
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On Thu, 2017-08-31 at 17:44 +0200, Greg Kroah-Hartman wrote:
> 4.9-stable review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Jiri Slaby <jslaby@suse.cz>
> 
> commit 6f17581788206444cbbcdbc107498f85e9765e3d upstream.
> 
> gcc 7 complains:
> drivers/net/wireless/intersil/p54/fwio.c: In function 'p54_scan':
> drivers/net/wireless/intersil/p54/fwio.c:491:4: warning: 'memset' used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size]
> 
> Fix that by passing the correct size to memset.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Christian Lamparter <chunkeey@googlemail.com>
> Cc: Kalle Valo <kvalo@codeaurora.org>
> Acked-by: Christian Lamparter <chunkeey@googlemail.com>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> ---
>  drivers/net/wireless/intersil/p54/fwio.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/drivers/net/wireless/intersil/p54/fwio.c
> +++ b/drivers/net/wireless/intersil/p54/fwio.c
> @@ -488,7 +488,7 @@ int p54_scan(struct p54_common *priv, u1
>  
>  			entry += sizeof(__le16);
>  			chan->pa_points_per_curve = 8;
> -			memset(chan->curve_data, 0, sizeof(*chan->curve_data));
> +			memset(chan->curve_data, 0, sizeof(chan->curve_data));
>  			memcpy(chan->curve_data, entry,
>  			       sizeof(struct p54_pa_curve_data_sample) *
>  			       min((u8)8, curve_data->points_per_channel));
> 

Why is this change correct?

curve_data is a pointer.

This now clears the sizeof a pointer and not
the sizeof struct p54_cal_database