Re: [PATCH] ASoC: SOF: Intel: Check the bar size before remapping

[Pierre-Louis Bossart]

On 4/9/22 09:39, Zheyu Ma wrote:
> The driver should use the pci_resource_len() to get the actual length of
> pci bar, and compare it with the expect value. If the bar size is too
> small (such as a broken device), the driver should return an error.
> 
> Signed-off-by: Zheyu Ma <zheyuma97@xxxxxxxxx>
> ---
>  sound/soc/sof/intel/pci-tng.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/soc/sof/intel/pci-tng.c b/sound/soc/sof/intel/pci-tng.c
> index 6efef225973f..7d502cc3ca80 100644
> --- a/sound/soc/sof/intel/pci-tng.c
> +++ b/sound/soc/sof/intel/pci-tng.c
> @@ -75,7 +75,11 @@ static int tangier_pci_probe(struct snd_sof_dev *sdev)
>  
>  	/* LPE base */
>  	base = pci_resource_start(pci, desc->resindex_lpe_base) - IRAM_OFFSET;
> -	size = PCI_BAR_SIZE;
> +	size = pci_resource_len(pci, desc->resindex_lpe_base);
> +	if (size < PCI_BAR_SIZE) {
> +		dev_err(sdev->dev, "error: I/O region is too small.\n");
> +		return -ENODEV;
> +	}

May I ask how you found this issue?

I am not clear on why there's a patch dedicated for a single device, but the same pattern in hda.c and in the HDaudio legacy driver exists.

>  
>  	dev_dbg(sdev->dev, "LPE PHY base at 0x%x size 0x%x", base, size);
>  	sdev->bar[DSP_BAR] = devm_ioremap(sdev->dev, base, size);