On Thu, 2022-11-03 at 17:30 -0700, Dan Williams wrote:
> When a region is deleted any targets that have been previously assigned
> to that region hold references to it. Trigger those references to
> drop by detaching all targets at unregister_region() time.
>
> Otherwise that region object will leak as userspace has lost the ability
> to detach targets once region sysfs is torn down.
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Fixes: b9686e8c8e39 ("cxl/region: Enable the assignment of endpoint decoders to regions")
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
> drivers/cxl/core/region.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
Looks good,
Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
>
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index d26ca7a6beae..c52465e09f26 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1557,8 +1557,19 @@ static struct cxl_region *to_cxl_region(struct device *dev)
> static void unregister_region(void *dev)
> {
> struct cxl_region *cxlr = to_cxl_region(dev);
> + struct cxl_region_params *p = &cxlr->params;
> + int i;
>
> device_del(dev);
> +
> + /*
> + * Now that region sysfs is shutdown, the parameter block is now
> + * read-only, so no need to hold the region rwsem to access the
> + * region parameters.
> + */
> + for (i = 0; i < p->interleave_ways; i++)
> + detach_target(cxlr, i);
> +
> cxl_region_iomem_release(cxlr);
> put_device(dev);
> }
>
