From: Larry Finger <Larry.Finger@lwfinger.net>
To: Wei Yongjun <weiyj.lk@gmail.com>
Cc: lauro.venancio@openbossa.org, aloisio.almeida@openbossa.org,
sameo@linux.intel.com, yongjun_wei@trendmicro.com.cn,
linux-wireless@vger.kernel.org
Subject: Re: [PATCH v2] NFC: pn544_hci: move the dereference below the NULL test
Date: Fri, 07 Sep 2012 21:03:43 -0500 [thread overview]
Message-ID: <504AA77F.2010906@lwfinger.net> (raw)
In-Reply-To: <CAPgLHd_gF6X91JPGZK0f7vhSAK+d74YfbcvPn+givzMr=44+Sw@mail.gmail.com>
On 09/07/2012 08:53 PM, Wei Yongjun wrote:
> From: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
>
> The dereference should be moved below the NULL test.
>
> spatch with a semantic match is used to found this.
> (http://coccinelle.lip6.fr/)
>
> Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
> ---
> drivers/nfc/pn544_hci.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nfc/pn544_hci.c b/drivers/nfc/pn544_hci.c
> index aa71807..7b20f2d 100644
> --- a/drivers/nfc/pn544_hci.c
> +++ b/drivers/nfc/pn544_hci.c
> @@ -341,13 +341,14 @@ flush:
> static irqreturn_t pn544_hci_irq_thread_fn(int irq, void *dev_id)
> {
> struct pn544_hci_info *info = dev_id;
> - struct i2c_client *client = info->i2c_dev;
> + struct i2c_client *client;
> struct sk_buff *skb = NULL;
> int r;
>
> BUG_ON(!info);
> BUG_ON(irq != info->i2c_dev->irq);
>
> + client = info->i2c_dev;
As long as you are reworking this section, doesn't BUG_ON seem a little harsh? I
do not think the kernel should ever be crashed because a non-essential driver is
messed up. As the patch would be a totally different change, it should be a new
submission, but I think each of these conditions should trigger a WARN_ON_ONCE,
and return IRQ_NONE when they occur.
Larry
> dev_dbg(&client->dev, "IRQ\n");
>
> if (info->hard_fault != 0)
>
>
> --
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> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
next prev parent reply other threads:[~2012-09-08 2:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-08 1:53 [PATCH v2] NFC: pn544_hci: move the dereference below the NULL test Wei Yongjun
2012-09-08 2:03 ` Larry Finger [this message]
-- strict thread matches above, loose matches on Subject: below --
2012-09-08 3:34 Wei Yongjun
2012-09-08 12:37 ` Larry Finger
2012-09-10 13:10 ` Kalle Valo
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