Subject: Re: [net-next 06/10] ixgbe: eliminate Smatch warnings in ixgbe_debugfs.c

From: Dan Carpenter <[email-masked]>
Date: Wed, 21 Nov 2012 14:04:09 +0300

On Wed, Nov 21, 2012 at 02:47:32AM -0800, Jeff Kirsher wrote:
> +	len = simple_write_to_buffer(ixgbe_dbg_reg_ops_buf,
> +				     sizeof(ixgbe_dbg_reg_ops_buf)-1,
> +				     ppos,
> +				     buffer,
> +				     count);
> +	if (len < 0)
> +		return -EFAULT;

Any negative return is bad.

	if (len)
		return len;

> +
> +	ixgbe_dbg_reg_ops_buf[len] = '\0';
>  
>  	if (strncmp(ixgbe_dbg_reg_ops_buf, "write", 5) == 0) {
>  		u32 reg, value;
> @@ -187,15 +196,15 @@ static ssize_t ixgbe_dbg_netdev_ops_write(struct file *filp,
>  	if (count >= sizeof(ixgbe_dbg_netdev_ops_buf))
>  		return -ENOSPC;
>  
> -	bytes_not_copied = copy_from_user(ixgbe_dbg_netdev_ops_buf,
> -					  buffer, count);
> -	if (bytes_not_copied < 0)
> -		return bytes_not_copied;
> -	else if (bytes_not_copied < count)
> -		count -= bytes_not_copied;
> -	else
> -		return -ENOSPC;
> -	ixgbe_dbg_netdev_ops_buf[count] = '\0';
> +	len = simple_write_to_buffer(ixgbe_dbg_netdev_ops_buf,
> +				     sizeof(ixgbe_dbg_netdev_ops_buf)-1,
> +				     ppos,
> +				     buffer,
> +				     count);
> +	if (len < 0)
> +		return -EFAULT;

Same.

> +
> +	ixgbe_dbg_netdev_ops_buf[len] = '\0';

regards,
dan carpenter