Re: [PATCH 1/4] devcoredump: use memory_read_from_buffer

[Johannes Berg]

On Thu, 2019-05-02 at 17:59 +0900, Akinobu Mita wrote:
> Use memory_read_from_buffer() to simplify devcd_readv().

Reviewed-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>

> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> Cc: Keith Busch <keith.busch@xxxxxxxxx>
> Cc: Jens Axboe <axboe@xxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
> ---
>  drivers/base/devcoredump.c | 11 +----------
>  1 file changed, 1 insertion(+), 10 deletions(-)
> 
> diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c
> index f1a3353..3c960a6 100644
> --- a/drivers/base/devcoredump.c
> +++ b/drivers/base/devcoredump.c
> @@ -164,16 +164,7 @@ static struct class devcd_class = {
>  static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count,
>  			   void *data, size_t datalen)
>  {
> -	if (offset > datalen)
> -		return -EINVAL;
> -
> -	if (offset + count > datalen)
> -		count = datalen - offset;
> -
> -	if (count)
> -		memcpy(buffer, ((u8 *)data) + offset, count);
> -
> -	return count;
> +	return memory_read_from_buffer(buffer, count, &offset, data, datalen);
>  }
>  
>  static void devcd_freev(void *data)