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Date:   Sun, 15 Dec 2019 19:28:14 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Aditya Pakki <pakki001@umn.edu>
Cc:     devel@driverdev.osuosl.org, Vandana BN <bnvandana@gmail.com>,
        Harsh Jain <harshjain32@gmail.com>, kjlu@umn.edu,
        linux-kernel@vger.kernel.org,
        Simon =?iso-8859-1?Q?Sandstr=F6m?= <simon@nikanor.nu>
Subject: Re: [PATCH] staging: kpc2000: replace assertion with recovery code
Message-ID: <20191215182814.GA859066@kroah.com>
References: <20191215181243.31519-1-pakki001@umn.edu>
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On Sun, Dec 15, 2019 at 12:12:37PM -0600, Aditya Pakki wrote:
> In kpc_dma_transfer, if either priv or ldev is NULL, crashing the
> process is excessive and is not needed. Instead of asserting, by
> passing the error upstream, the error can be handled.
> 
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
> ---
>  drivers/staging/kpc2000/kpc_dma/fileops.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/kpc2000/kpc_dma/fileops.c b/drivers/staging/kpc2000/kpc_dma/fileops.c
> index cb52bd9a6d2f..1c4633267cc1 100644
> --- a/drivers/staging/kpc2000/kpc_dma/fileops.c
> +++ b/drivers/staging/kpc2000/kpc_dma/fileops.c
> @@ -49,9 +49,11 @@ static int kpc_dma_transfer(struct dev_private_data *priv,
>  	u64 dma_addr;
>  	u64 user_ctl;
>  
> -	BUG_ON(priv == NULL);
> +	if (!priv)
> +		return -EINVAL;

How can prive ever be NULL here?  Can you track back to all callers to
verify this?  If so, just remove the check.

thanks,

greg k-h