Re: [PATCH] vhost: handle error while adding split ranges to iotlb

[Stefano Garzarella]

On Sat, Mar 12, 2022 at 07:41:21PM +0530, Anirudh Rayabharam wrote:
> vhost_iotlb_add_range_ctx() handles the range [0, ULONG_MAX] by
> splitting it into two ranges and adding them separately. The return
> value of adding the first range to the iotlb is currently ignored.
> Check the return value and bail out in case of an error.

We could add:

Fixes: e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries")

> Signed-off-by: Anirudh Rayabharam <mail@xxxxxxxxxxxxx>
> ---
> drivers/vhost/iotlb.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
> index 40b098320b2a..5829cf2d0552 100644
> --- a/drivers/vhost/iotlb.c
> +++ b/drivers/vhost/iotlb.c
> @@ -62,8 +62,12 @@ int vhost_iotlb_add_range_ctx(struct vhost_iotlb *iotlb,
> 	 */
> 	if (start == 0 && last == ULONG_MAX) {
> 		u64 mid = last / 2;
> +		int err = vhost_iotlb_add_range_ctx(iotlb, start, mid, addr,
> +				perm, opaque);
> +
> +		if (err)
> +			return err;
>
> -		vhost_iotlb_add_range_ctx(iotlb, start, mid, addr, perm, opaque);
> 		addr += mid + 1;
> 		start = mid + 1;
> 	}
> --
> 2.35.1

Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>