Re: [PATCH V4 1/2] PCI: rcar: Move the inbound index check

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Sat, Oct 26, 2019 at 08:26:58PM +0200, marek.vasut@gmail.com wrote:
> From: Marek Vasut <marek.vasut+renesas@gmail.com>
> 
> Since the $idx variable value is stored across multiple calls to
> rcar_pcie_inbound_ranges() function, and the $idx value is used to
> index registers which are written, subsequent calls might cause
> the $idx value to be high enough to trigger writes into nonexistent
> registers.
> 
> Fix this by moving the $idx value check to the beginning of the loop.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> Reviewed-by: Andrew Murray <andrew.murray@arm.com>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: linux-renesas-soc@vger.kernel.org
> To: linux-pci@vger.kernel.org
> ---
> V2: New patch
> V3: Adjust the check to idx >= MAX_NR_INBOUND_MAPS - 1
> V4: Rebase on next/master
> ---
>  drivers/pci/controller/pcie-rcar.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)

Applied both patches to pci/rcar, thanks !

Lorenzo

> diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
> index e45bb2a7bfa5..b2a5c3e94245 100644
> --- a/drivers/pci/controller/pcie-rcar.c
> +++ b/drivers/pci/controller/pcie-rcar.c
> @@ -1049,6 +1049,10 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
>  	mask &= ~0xf;
>  
>  	while (cpu_addr < cpu_end) {
> +		if (idx >= MAX_NR_INBOUND_MAPS - 1) {
> +			dev_err(pcie->dev, "Failed to map inbound regions!\n");
> +			return -EINVAL;
> +		}
>  		/*
>  		 * Set up 64-bit inbound regions as the range parser doesn't
>  		 * distinguish between 32 and 64-bit types.
> @@ -1068,11 +1072,6 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
>  		pci_addr += size;
>  		cpu_addr += size;
>  		idx += 2;
> -
> -		if (idx > MAX_NR_INBOUND_MAPS) {
> -			dev_err(pcie->dev, "Failed to map inbound regions!\n");
> -			return -EINVAL;
> -		}
>  	}
>  	*index = idx;
>  
> -- 
> 2.23.0
>