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Subject: Re: [PATCH 18/23] cx18: Replace memcpy with struct assignment
From: Andy Walls <awalls@md.metrocast.net>
To: Ezequiel Garcia <elezegarcia@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        Julia.Lawall@lip6.fr, kernel-janitors@vger.kernel.org,
        Peter Senna Tschudin <peter.senna@gmail.com>
Date: Tue, 23 Oct 2012 18:17:28 -0400
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	 <1351022246-8201-18-git-send-email-elezegarcia@gmail.com>
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On Tue, 2012-10-23 at 16:57 -0300, Ezequiel Garcia wrote:
> This kind of memcpy() is error-prone. Its replacement with a struct
> assignment is prefered because it's type-safe and much easier to read.
> 
> Found by coccinelle. Hand patched and reviewed.
> Tested by compilation only.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @@
> identifier struct_name;
> struct struct_name to;
> struct struct_name from;
> expression E;
> @@
> -memcpy(&(to), &(from), E);
> +to = from;
> // </smpl>
> 
> Cc: Andy Walls <awalls@md.metrocast.net>

Signed-off-by: Andy Walls <awalls@md.metrocast.net>

> Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
> Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
> ---
>  drivers/media/pci/cx18/cx18-i2c.c |    6 ++----
>  1 files changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/pci/cx18/cx18-i2c.c b/drivers/media/pci/cx18/cx18-i2c.c
> index 51609d5..930d40f 100644
> --- a/drivers/media/pci/cx18/cx18-i2c.c
> +++ b/drivers/media/pci/cx18/cx18-i2c.c
> @@ -240,15 +240,13 @@ int init_cx18_i2c(struct cx18 *cx)
>  
>  	for (i = 0; i < 2; i++) {
>  		/* Setup algorithm for adapter */
> -		memcpy(&cx->i2c_algo[i], &cx18_i2c_algo_template,
> -			sizeof(struct i2c_algo_bit_data));
> +		cx->i2c_algo[i] = cx18_i2c_algo_template;
>  		cx->i2c_algo_cb_data[i].cx = cx;
>  		cx->i2c_algo_cb_data[i].bus_index = i;
>  		cx->i2c_algo[i].data = &cx->i2c_algo_cb_data[i];
>  
>  		/* Setup adapter */
> -		memcpy(&cx->i2c_adap[i], &cx18_i2c_adap_template,
> -			sizeof(struct i2c_adapter));
> +		cx->i2c_adap[i] = cx18_i2c_adap_template;
>  		cx->i2c_adap[i].algo_data = &cx->i2c_algo[i];
>  		sprintf(cx->i2c_adap[i].name + strlen(cx->i2c_adap[i].name),
>  				" #%d-%d", cx->instance, i);