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* [bug report] fpga: dfl: fme: add performance reporting support
@ 2020-05-02 13:24 Dan Carpenter
  2020-05-06  6:31 ` Xu Yilun
  0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2020-05-02 13:24 UTC (permalink / raw)
  To: hao.wu; +Cc: linux-fpga

Hello Wu Hao,

The patch 724142f8c42a: "fpga: dfl: fme: add performance reporting
support" from Apr 27, 2020, leads to the following static checker
warning:

	drivers/fpga/dfl-fme-perf.c:948 fme_perf_offline_cpu()
	error: potential NULL dereference 'priv'.

drivers/fpga/dfl-fme-perf.c
   941  static int fme_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
   942  {
   943          struct fme_perf_priv *priv;
   944          int target;
   945  
   946          priv = hlist_entry_safe(node, struct fme_perf_priv, node);
                                  ^^^^^
It doesn't make sense to use the _safe() version if we're not going to
check for NULL.

   947  
   948          if (cpu != priv->cpu)
   949                  return 0;
   950  
   951          target = cpumask_any_but(cpu_online_mask, cpu);
   952          if (target >= nr_cpu_ids)
   953                  return 0;
   954  
   955          priv->cpu = target;
   956          return 0;
   957  }

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [bug report] fpga: dfl: fme: add performance reporting support
  2020-05-02 13:24 [bug report] fpga: dfl: fme: add performance reporting support Dan Carpenter
@ 2020-05-06  6:31 ` Xu Yilun
  2020-05-07  6:42   ` Wu, Hao
  0 siblings, 1 reply; 3+ messages in thread
From: Xu Yilun @ 2020-05-06  6:31 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: hao.wu, linux-fpga

On Sat, May 02, 2020 at 04:24:19PM +0300, Dan Carpenter wrote:
> Hello Wu Hao,
> 
> The patch 724142f8c42a: "fpga: dfl: fme: add performance reporting
> support" from Apr 27, 2020, leads to the following static checker
> warning:
> 
> 	drivers/fpga/dfl-fme-perf.c:948 fme_perf_offline_cpu()
> 	error: potential NULL dereference 'priv'.
> 
> drivers/fpga/dfl-fme-perf.c
>    941  static int fme_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
>    942  {
>    943          struct fme_perf_priv *priv;
>    944          int target;
>    945  
>    946          priv = hlist_entry_safe(node, struct fme_perf_priv, node);
>                                   ^^^^^
> It doesn't make sense to use the _safe() version if we're not going to
> check for NULL.

Thanks for catching this. Will fix it.

Regards,
Yilun.

> 
>    947  
>    948          if (cpu != priv->cpu)
>    949                  return 0;
>    950  
>    951          target = cpumask_any_but(cpu_online_mask, cpu);
>    952          if (target >= nr_cpu_ids)
>    953                  return 0;
>    954  
>    955          priv->cpu = target;
>    956          return 0;
>    957  }
> 
> regards,
> dan carpenter

^ permalink raw reply	[flat|nested] 3+ messages in thread

* RE: [bug report] fpga: dfl: fme: add performance reporting support
  2020-05-06  6:31 ` Xu Yilun
@ 2020-05-07  6:42   ` Wu, Hao
  0 siblings, 0 replies; 3+ messages in thread
From: Wu, Hao @ 2020-05-07  6:42 UTC (permalink / raw)
  To: Xu, Yilun, Dan Carpenter; +Cc: linux-fpga@vger.kernel.org

> On Sat, May 02, 2020 at 04:24:19PM +0300, Dan Carpenter wrote:
> > Hello Wu Hao,
> >
> > The patch 724142f8c42a: "fpga: dfl: fme: add performance reporting
> > support" from Apr 27, 2020, leads to the following static checker
> > warning:
> >
> > 	drivers/fpga/dfl-fme-perf.c:948 fme_perf_offline_cpu()
> > 	error: potential NULL dereference 'priv'.
> >
> > drivers/fpga/dfl-fme-perf.c
> >    941  static int fme_perf_offline_cpu(unsigned int cpu, struct hlist_node
> *node)
> >    942  {
> >    943          struct fme_perf_priv *priv;
> >    944          int target;
> >    945
> >    946          priv = hlist_entry_safe(node, struct fme_perf_priv, node);
> >                                   ^^^^^
> > It doesn't make sense to use the _safe() version if we're not going to
> > check for NULL.
> 
> Thanks for catching this. Will fix it.

Yes, it's not necessary to use _safe version here.
Thanks Dan for reporting this, and thanks Yilun for covering this when
I was on leave.

Hao

> 
> Regards,
> Yilun.
> 
> >
> >    947
> >    948          if (cpu != priv->cpu)
> >    949                  return 0;
> >    950
> >    951          target = cpumask_any_but(cpu_online_mask, cpu);
> >    952          if (target >= nr_cpu_ids)
> >    953                  return 0;
> >    954
> >    955          priv->cpu = target;
> >    956          return 0;
> >    957  }
> >
> > regards,
> > dan carpenter

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-05-07  6:43 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2020-05-02 13:24 [bug report] fpga: dfl: fme: add performance reporting support Dan Carpenter
2020-05-06  6:31 ` Xu Yilun
2020-05-07  6:42   ` Wu, Hao

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