Re: [PATCH v4 1/3] PCI: dwc: allow to limit registers set length

[Lorenzo Pieralisi]

On Tue, Dec 04, 2018 at 05:55:26PM +0100, Stefan Agner wrote:
> Add length to the struct dw_pcie and check that the accessors
> dw_pcie_(rd|wr)_conf() do not read/write beyond that point.
> 
> Suggested-by: Trent Piepho <tpiepho@xxxxxxxxxx>
> Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
> ---
> Changes in v4:
> - Move length check to dw_pcie_rd_conf
> 
>  .../pci/controller/dwc/pcie-designware-host.c    | 16 ++++++++++++++--
>  drivers/pci/controller/dwc/pcie-designware.h     |  1 +
>  2 files changed, 15 insertions(+), 2 deletions(-)

Hi Stefan,

I wanted to ask you if this series should be considered for v5.1
inclusion, it is in the PCI backlog. If it is, let me have a look
and if it is OK to go I will likely ask you to rebase it.

Thanks,
Lorenzo

> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 692dd1b264fb..9fc0f7bd99f0 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -606,14 +606,20 @@ static int dw_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
>  			   int size, u32 *val)
>  {
>  	struct pcie_port *pp = bus->sysdata;
> +	struct dw_pcie *pci;
>  
>  	if (!dw_pcie_valid_device(pp, bus, PCI_SLOT(devfn))) {
>  		*val = 0xffffffff;
>  		return PCIBIOS_DEVICE_NOT_FOUND;
>  	}
>  
> -	if (bus->number == pp->root_bus_nr)
> +	if (bus->number == pp->root_bus_nr) {
> +		pci = to_dw_pcie_from_pp(pp);
> +		if (pci->dbi_length && where + size > pci->dbi_length)
> +			return PCIBIOS_BAD_REGISTER_NUMBER;
> +
>  		return dw_pcie_rd_own_conf(pp, where, size, val);
> +	}
>  
>  	return dw_pcie_rd_other_conf(pp, bus, devfn, where, size, val);
>  }
> @@ -622,12 +628,18 @@ static int dw_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
>  			   int where, int size, u32 val)
>  {
>  	struct pcie_port *pp = bus->sysdata;
> +	struct dw_pcie *pci;
>  
>  	if (!dw_pcie_valid_device(pp, bus, PCI_SLOT(devfn)))
>  		return PCIBIOS_DEVICE_NOT_FOUND;
>  
> -	if (bus->number == pp->root_bus_nr)
> +	if (bus->number == pp->root_bus_nr) {
> +		pci = to_dw_pcie_from_pp(pp);
> +		if (pci->dbi_length && where + size > pci->dbi_length)
> +			return PCIBIOS_BAD_REGISTER_NUMBER;
> +
>  		return dw_pcie_wr_own_conf(pp, where, size, val);
> +	}
>  
>  	return dw_pcie_wr_other_conf(pp, bus, devfn, where, size, val);
>  }
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 9943d8c68335..9cd7bdc94200 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -229,6 +229,7 @@ struct dw_pcie {
>  	void __iomem		*dbi_base2;
>  	/* Used when iatu_unroll_enabled is true */
>  	void __iomem		*atu_base;
> +	int			dbi_length;
>  	u32			num_viewport;
>  	u8			iatu_unroll_enabled;
>  	struct pcie_port	pp;
> -- 
> 2.19.1
>