Re: [PATCH v3] PCI: mediatek-gen3: Fix refcount leak in mtk_pcie_init_irq_domains

From: Jianjun Wang <jianjun.wang@mediatek.com>
To: Bjorn Helgaas <helgaas@kernel.org>, Miaoqian Lin <linmq006@gmail.com>
Cc: miles.chen@mediatek.com, "Ryder Lee" <ryder.lee@mediatek.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"Marc Zyngier" <maz@kernel.org>,
	linux-pci@vger.kernel.org, linux-mediatek@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3] PCI: mediatek-gen3: Fix refcount leak in mtk_pcie_init_irq_domains
Date: Thu, 9 Jun 2022 10:16:46 +0800	[thread overview]
Message-ID: <f3f38fe193b949956691ed788e23e3c3bd59c2da.camel@mediatek.com> (raw)
In-Reply-To: <20220608212058.GA424368@bhelgaas>

Hi Bjorn,

On Wed, 2022-06-08 at 16:20 -0500, Bjorn Helgaas wrote:
> On Wed, Jun 01, 2022 at 08:12:58AM +0400, Miaoqian Lin wrote:
> > of_get_child_by_name() returns a node pointer with refcount
> > incremented, we should use of_node_put() on it when not need
> > anymore.
> > Add missing of_node_put() to avoid refcount leak.
> > 
> > Fixes: 814cceebba9b ("PCI: mediatek-gen3: Add INTx support")
> > Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> 
> Can we get an ack from Ryder or Jianjun, as well, since they're
> listed
> as maintainers?

Sure, thanks for the reminder.

Acked-by: Jianjun Wang <jianjun.wang@mediatek.com>
> 
> > ---
> > changes in v2:
> > - move of_node_put(intc_node) right after irq_domain_add_linear to
> > cover
> > normal path and error paths.
> > ---
> > changes in v3:
> > - call of_node_put() in error paths with goto, and call
> > of_node_put() before
> >   return 0 in normal path. Since this function has a goto part to
> > handle
> >   resources, so put them together, as suggested by Miles Chen <
> > miles.chen@mediatek.com>
> > 
> > v1 link: 
> > https://lore.kernel.org/all/20220526110246.53502-1-linmq006@gmail.com/
> > v2 link: 
> > https://lore.kernel.org/all/20220530064807.34534-1-linmq006@gmail.com/
> > ---
> >  drivers/pci/controller/pcie-mediatek-gen3.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c
> > b/drivers/pci/controller/pcie-mediatek-gen3.c
> > index 3e8d70bfabc6..bceed28446ed 100644
> > --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> > +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> > @@ -600,7 +600,8 @@ static int mtk_pcie_init_irq_domains(struct
> > mtk_gen3_pcie *pcie)
> >  						  &intx_domain_ops,
> > pcie);
> >  	if (!pcie->intx_domain) {
> >  		dev_err(dev, "failed to create INTx IRQ domain\n");
> > -		return -ENODEV;
> > +		ret = -ENODEV;
> > +		goto out_put_node;
> >  	}
> >  
> >  	/* Setup MSI */
> > @@ -623,13 +624,15 @@ static int mtk_pcie_init_irq_domains(struct
> > mtk_gen3_pcie *pcie)
> >  		goto err_msi_domain;
> >  	}
> >  
> > +	of_node_put(intc_node);
> >  	return 0;
> >  
> >  err_msi_domain:
> >  	irq_domain_remove(pcie->msi_bottom_domain);
> >  err_msi_bottom_domain:
> >  	irq_domain_remove(pcie->intx_domain);
> > -
> > +out_put_node:
> > +	of_node_put(intc_node);
> >  	return ret;
> >  }
> >  
> > -- 
> > 2.25.1
> > 
> > 
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