Re: [PATCH v4 0/4] PCI: arm64/powerpc: Fix parsing of linux,pci-probe-only

From: Rob Herring
Date: Fri Sep 04 2015 - 14:53:23 EST


On Fri, Sep 4, 2015 at 11:50 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote:
> The pci-host-generic driver parses the linux,pci-probe-only property,
> and assumes that it will have a boolean parameter.
>
> Turns out that the Seattle DTS file has a naked "linux,pci-probe-only"
> property, which leads to the driver dereferencing some unsuspecting
> memory location. Nothing really bad happens (we end up reading some
> other bit of DT, fortunately), but that not a reason to keep it this
> way. Turns out that the Pseries code (where this code was lifted from)
> may suffer from the same issue.
>
> The first patch introduces a common (and fixed) version of that check
> that can be used by drivers and architectures that require it. The two
> following patches change the pci-host-generic driver and the powerpc
> code to use it.
>
> Finally, the bad property is removed from the Seatle DTS, because it
> is simply not necessary (it actually prevents me from using SR-IOV,
> which otherwise runs fine without the probe-only thing).
>
> This has been tested on the offending Seattle board.
>
> * From v3:
> - Restrict the property lookup to /chosen (Rob)
> - Acked-by on patch #4 from Suravee
> - I swear this is the last time I rework these patches! ;-)
>
> * From v2:
> - Use of_property_read_u32 to safely read the property (Rob)
> - Add a log message to indicate when we enable probe-only
> (probably quite useful for debugging)
>
> * From v1:
> - Consolidate the parsing in of_pci.c (Bjorn)
>
> Marc Zyngier (4):
> of/pci: Add of_pci_check_probe_only to parse "linux,pci-probe-only"
> PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
> powerpc: PCI: Fix lookup of linux,pci-probe-only property
> arm64: dts: Drop linux,pci-probe-only from the Seattle DTS
>
> arch/arm64/boot/dts/amd/amd-overdrive.dts | 1 -
> arch/powerpc/platforms/pseries/setup.c | 14 ++------------
> drivers/of/of_pci.c | 28 ++++++++++++++++++++++++++++
> drivers/pci/host/pci-host-generic.c | 9 +--------
> include/linux/of_pci.h | 3 +++
> 5 files changed, 34 insertions(+), 21 deletions(-)

For the series:

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>

Rob
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