Re: [PATCH v2 7/7] iommu/vt-d: Remove BUG_ON in dmar_insert_dev_scope()

[Baolu Lu <baolu.lu@linux.intel.com>]

On 3/31/23 10:42 AM, Tina Zhang wrote:
> The dmar_insert_dev_scope() could fail if any unexpected condition is
> encountered. However, in this situation, the kernel should attempt
> recovery and proceed with execution. Remove BUG_ON with WARN_ON, so that
> kernel can avoid being crashed when an unexpected condition occurs.
> 
> Signed-off-by: Tina Zhang <tina.zhang@intel.com>
> ---
>   drivers/iommu/intel/dmar.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
> index 9684c96247f8..7eceee081235 100644
> --- a/drivers/iommu/intel/dmar.c
> +++ b/drivers/iommu/intel/dmar.c
> @@ -262,7 +262,8 @@ int dmar_insert_dev_scope(struct dmar_pci_notify_info *info,
>   						   get_device(dev));
>   				return 1;
>   			}
> -		BUG_ON(i >= devices_cnt);
> +		if (WARN_ON(i >= devices_cnt))
> +			return -EINVAL;

You have returned an error number. Do you still need a WARN_ON()?

>   	}
>   
>   	return 0;

Best regards,
baolu