Re: [PATCH] net: Remove casts to same type

[Ben Hutchings <bhutchings@solarflare.com>]

On Sun, 2012-06-03 at 20:41 -0700, Joe Perches wrote:
> Adding casts of objects to the same type is unnecessary
> and confusing for a human reader.
> 
> For example, this cast:
> 
> 	int y;
> 	int *p = (int *)&y;
> 
> I used the coccinelle script below to find and remove these
> unnecessary casts.  I manually removed the conversions this
> script produces of casts with __force and __user.
[...]
> diff --git a/net/9p/client.c b/net/9p/client.c
> index a170893..5cbea90 100644
> --- a/net/9p/client.c
> +++ b/net/9p/client.c
> @@ -1548,7 +1548,7 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
>  			kernel_buf = 1;
>  			indata = data;
>  		} else
> -			indata = (char *)udata;
> +			indata = udata;
>  		/*
>  		 * response header len is 11
>  		 * PDU Header(7) + IO Size (4)
[...]

This one is casting char __user * to char *.  We need a cast to let
sparse know this is deliberate, though presumably we need __force as
well.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.