From: "Jérôme Pouiller" <jerome.pouiller@silabs.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: devel@driverdev.osuosl.org, netdev@vger.kernel.org,
linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
Dan Carpenter <dan.carpenter@oracle.com>,
"David S . Miller" <davem@davemloft.net>,
Kalle Valo <kvalo@codeaurora.org>
Subject: Re: [PATCH 3/8] staging: wfx: standardize the error when vif does not exist
Date: Sat, 10 Oct 2020 15:29:34 +0200 [thread overview]
Message-ID: <5203347.001cLfkWmS@pc-42> (raw)
In-Reply-To: <20201010124034.GA1701199@kroah.com>
On Saturday 10 October 2020 14:40:34 CEST Greg Kroah-Hartman wrote:
> On Sat, Oct 10, 2020 at 02:22:13PM +0200, Jérôme Pouiller wrote:
> > On Friday 9 October 2020 20:52:47 CEST Kalle Valo wrote:
> > > Jerome Pouiller <Jerome.Pouiller@silabs.com> writes:
> > >
> > > > From: Jérôme Pouiller <jerome.pouiller@silabs.com>
> > > >
> > > > Smatch complains:
> > > >
> > > > drivers/staging/wfx/hif_rx.c:177 hif_scan_complete_indication() warn: potential NULL parameter dereference 'wvif'
> > > > drivers/staging/wfx/data_tx.c:576 wfx_flush() warn: potential NULL parameter dereference 'wvif'
> > > >
> > > > Indeed, if the vif id returned by the device does not exist anymore,
> > > > wdev_to_wvif() could return NULL.
> > > >
> > > > In add, the error is not handled uniformly in the code, sometime a
> > > > WARN() is displayed but code continue, sometime a dev_warn() is
> > > > displayed, sometime it is just not tested, ...
> > > >
> > > > This patch standardize that.
> > > >
> > > > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > > Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
> > > > ---
> > > > drivers/staging/wfx/data_tx.c | 5 ++++-
> > > > drivers/staging/wfx/hif_rx.c | 34 ++++++++++++++++++++++++----------
> > > > drivers/staging/wfx/sta.c | 4 ++++
> > > > 3 files changed, 32 insertions(+), 11 deletions(-)
> > > >
> > > > diff --git a/drivers/staging/wfx/data_tx.c b/drivers/staging/wfx/data_tx.c
> > > > index b4d5dd3d2d23..8db0be08daf8 100644
> > > > --- a/drivers/staging/wfx/data_tx.c
> > > > +++ b/drivers/staging/wfx/data_tx.c
> > > > @@ -431,7 +431,10 @@ static void wfx_skb_dtor(struct wfx_vif *wvif, struct sk_buff *skb)
> > > > sizeof(struct hif_req_tx) +
> > > > req->fc_offset;
> > > >
> > > > - WARN_ON(!wvif);
> > > > + if (!wvif) {
> > > > + pr_warn("%s: vif associated with the skb does not exist anymore\n", __func__);
> > > > + return;
> > > > + }
> > >
> > > I'm not really a fan of using function names in warning or error
> > > messages as it clutters the log. In debug messages I think they are ok.
> >
> > In the initial code, I used WARN() that far more clutters the log (I
> > have stated that a backtrace won't provide any useful information, so
> > pr_warn() was better suited).
> >
> > In add, in my mind, these warnings are debug messages. If they appears,
> > the user should probably report a bug.
> >
> > Finally, in this patch, I use the same message several times (ok, not
> > this particular one). So the function name is a way to differentiate
> > them.
>
> You should use dev_*() for these, that way you can properly determine
> the exact device as well.
Totally agree. I initially did that. However, the device is a field of
wvif which is NULL in this case.
I could have changed the code to get the real pointer to the device. But
I didn't want to clutter the code just for a debug message (and also
because I was a bit lazy).
--
Jérôme Pouiller
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next prev parent reply other threads:[~2020-10-10 13:29 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 17:12 [PATCH 0/8] staging: wfx: fix issues reported by Smatch Jerome Pouiller
2020-10-09 17:13 ` [PATCH 1/8] staging: wfx: improve error handling of hif_join() Jerome Pouiller
2020-10-09 17:13 ` [PATCH 2/8] staging: wfx: check memory allocation Jerome Pouiller
2020-10-09 18:51 ` Kalle Valo
2020-10-10 12:07 ` Jérôme Pouiller
2020-10-10 13:18 ` Dan Carpenter
2020-10-10 13:54 ` Dan Carpenter
2020-10-09 17:13 ` [PATCH 3/8] staging: wfx: standardize the error when vif does not exist Jerome Pouiller
2020-10-09 18:52 ` Kalle Valo
2020-10-10 12:22 ` Jérôme Pouiller
2020-10-10 12:40 ` Greg Kroah-Hartman
2020-10-10 13:29 ` Jérôme Pouiller [this message]
2020-10-09 17:13 ` [PATCH 4/8] staging: wfx: wfx_init_common() returns NULL on error Jerome Pouiller
2020-10-09 17:13 ` [PATCH 5/8] staging: wfx: increase robustness of hif_generic_confirm() Jerome Pouiller
2020-10-09 17:13 ` [PATCH 6/8] staging: wfx: gpiod_get_value() can return an error Jerome Pouiller
2020-10-09 17:13 ` [PATCH 7/8] staging: wfx: drop unicode characters from strings Jerome Pouiller
2020-10-09 17:13 ` [PATCH 8/8] staging: wfx: improve robustness of wfx_get_hw_rate() Jerome Pouiller
2020-10-16 1:50 ` Nathan Chancellor
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