Re: [PATCH] staging: comedi: comedi_fops.c: changed type in assignment to unsigned int *

[Ian Abbott]

On 15/07/2020 05:48, B K Karthik wrote:
> fixed a sparse warning by changing the type in
> assignment from void [noderef] __user * to unsigned int *
> (different address space)
>
> Signed-off-by: B K Karthik <karthik.bk2000@xxxxxxxx>
> ---
>   drivers/staging/comedi/comedi_fops.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
> index 3f70e5dfac39..4cc012e231b7 100644
> --- a/drivers/staging/comedi/comedi_fops.c
> +++ b/drivers/staging/comedi/comedi_fops.c
> @@ -2956,7 +2956,7 @@ static int get_compat_cmd(struct comedi_cmd *cmd,
>   	cmd->scan_end_arg = v32.scan_end_arg;
>   	cmd->stop_src = v32.stop_src;
>   	cmd->stop_arg = v32.stop_arg;
> -	cmd->chanlist = compat_ptr(v32.chanlist);
> +	cmd->chanlist = (unsigned int *) compat_ptr(v32.chanlist);

That should be:

	cmd->chanlist = (unsigned int __force *)compat_ptr(v32.chanlist);

>   	cmd->chanlist_len = v32.chanlist_len;
>   	cmd->data = compat_ptr(v32.data);
>   	cmd->data_len = v32.data_len;

A reverse cast is required in put_compat_cmd():

	v32.chanlist = ptr_to_compat((unsigned int __user *)cmd->chanlist);

Those changes will get rid of the sparse warnings.

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