From: Catalin Marinas <catalin.marinas@arm.com>
To: George Cherian <gcherian@marvell.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"guohanjun@huawei.com" <guohanjun@huawei.com>,
"will.deacon@arm.com" <will.deacon@arm.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Yang Yingliang <yangyingliang@huawei.com>,
"bhelgaas@google.com" <bhelgaas@google.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] arm64: PCI: fix memleak when calling pci_iomap/unmap()
Date: Mon, 7 Sep 2020 12:21:19 +0100 [thread overview]
Message-ID: <20200907112118.GD26513@gaia> (raw)
In-Reply-To: <BYAPR18MB267959E6FE4BEF38D0A4611EC5280@BYAPR18MB2679.namprd18.prod.outlook.com>
+ Lorenzo
On Mon, Sep 07, 2020 at 10:51:21AM +0000, George Cherian wrote:
> Catalin Marinas <catalin.marinas@arm.com> wrote:
> > On Sat, Sep 05, 2020 at 10:48:11AM +0800, Yang Yingliang wrote:
> > > diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index
> > > 1006ed2d7c604..ddfa1c53def48 100644
> > > --- a/arch/arm64/kernel/pci.c
> > > +++ b/arch/arm64/kernel/pci.c
> > > @@ -217,4 +217,9 @@ void pcibios_remove_bus(struct pci_bus *bus)
> > > acpi_pci_remove_bus(bus);
> > > }
> > >
> > > +void pci_iounmap(struct pci_dev *dev, void __iomem *addr) {
> > > + iounmap(addr);
> > > +}
> > > +EXPORT_SYMBOL(pci_iounmap);
> >
> > So, what's wrong with the generic pci_iounmap() implementation?
> > Shouldn't it call iounmap() already?
>
> Since ARM64 selects CONFIG_GENERIC_PCI_IOMAP and not
> CONFIG_GENERIC_IOMAP, the pci_iounmap function is reduced to a NULL
> function. Due to this, even the managed release variants or even the explicit
> pci_iounmap calls doesn't really remove the mappings leading to leak.
Ah, I missed the fact that pci_iounmap() depends on a different
config option.
> https://lkml.org/lkml/2020/8/20/28
So is this going to be fixed in the generic code? That would be my
preference.
A problem with the iounmap() in the proposed patch is that the region
may have been an I/O port, so we could end up unmapping the I/O space.
--
Catalin
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next prev parent reply other threads:[~2020-09-07 11:22 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-05 2:48 [PATCH] arm64: PCI: fix memleak when calling pci_iomap/unmap() Yang Yingliang
2020-09-07 10:45 ` Catalin Marinas
[not found] ` <BYAPR18MB267959E6FE4BEF38D0A4611EC5280@BYAPR18MB2679.namprd18.prod.outlook.com>
2020-09-07 11:21 ` Catalin Marinas [this message]
2020-09-09 11:36 ` Lorenzo Pieralisi
2020-09-09 13:54 ` Catalin Marinas
2020-09-09 17:37 ` Lorenzo Pieralisi
2020-09-11 9:51 ` Lorenzo Pieralisi
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