Re: [PATCH v3] staging: qlge: fix build breakage with dumping enabled

[Coiby Xu]

On Thu, Sep 03, 2020 at 12:49:18PM +0900, Benjamin Poirier wrote:
> On 2020-09-02 22:00 +0800, Coiby Xu wrote:
> > This fixes commit 0107635e15ac
> > ("staging: qlge: replace pr_err with netdev_err") which introduced an
> > build breakage of missing `struct ql_adapter *qdev` for some functions
> > and a warning of type mismatch with dumping enabled, i.e.,
> >
> > $ make CFLAGS_MODULE="QL_ALL_DUMP=1 QL_OB_DUMP=1 QL_CB_DUMP=1 \
> >   QL_IB_DUMP=1 QL_REG_DUMP=1 QL_DEV_DUMP=1" M=drivers/staging/qlge
> >
> > qlge_dbg.c: In function ‘ql_dump_ob_mac_rsp’:
> > qlge_dbg.c:2051:13: error: ‘qdev’ undeclared (first use in this function); did you mean ‘cdev’?
> >  2051 |  netdev_err(qdev->ndev, "%s\n", __func__);
> >       |             ^~~~
> > qlge_dbg.c: In function ‘ql_dump_routing_entries’:
> > qlge_dbg.c:1435:10: warning: format ‘%s’ expects argument of type ‘char *’, but argument 3 has type ‘int’ [-Wformat=]
> >  1435 |        "%s: Routing Mask %d = 0x%.08x\n",
> >       |         ~^
> >       |          |
> >       |          char *
> >       |         %d
> >  1436 |        i, value);
> >       |        ~
> >       |        |
> >       |        int
> > qlge_dbg.c:1435:37: warning: format ‘%x’ expects a matching ‘unsigned int’ argument [-Wformat=]
> >  1435 |        "%s: Routing Mask %d = 0x%.08x\n",
> >       |                                 ~~~~^
> >       |                                     |
> >       |                                     unsigned int
> >
> > Fixes: 0107635e15ac ("staging: qlge: replace pr_err with netdev_err")
> > Reported-by: Benjamin Poirier <benjamin.poirier@xxxxxxxxx>
> > Suggested-by: Benjamin Poirier <benjamin.poirier@xxxxxxxxx>
> > Signed-off-by: Coiby Xu <coiby.xu@xxxxxxxxx>
> > ---
>
> Thanks for following up on this issue.
>
> [...]
> > @@ -1632,8 +1635,8 @@ void ql_dump_wqicb(struct wqicb *wqicb)
> >
> >  void ql_dump_tx_ring(struct tx_ring *tx_ring)
> >  {
> > -	if (!tx_ring)
> > -		return;
> > +	struct ql_adapter *qdev = tx_ring->qdev;
> > +
> >  	netdev_err(qdev->ndev, "===================== Dumping tx_ring %d ===============\n",
> >  		   tx_ring->wq_id);
> >  	netdev_err(qdev->ndev, "tx_ring->base = %p\n", tx_ring->wq_base);
>
> Did you actually check to confirm that the test can be removed?

Thank you for the reminding! For the current code, when ql_dump_tx_ring
is called, tx_ring would never be null.

> This is something that you should mention in the changelog at the very
> least since that change is not directly about fixing the build breakage
> and if it's wrong, it can lead to null pointer deref.

I thought it is common practice in C that the caller makes sure
the passed parameter isn't a null pointer because a QEMU developer
also gave me the same advice after reviewing one of my patches for
QEMU a few weeks ago. I'll mention this in the commit message. Thank
you for the suggestion!


--
Best regards,
Coiby