On 11/3/2022 5:30 PM, 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>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
drivers/cxl/core/region.c | 11 +++++++++++
1 file changed, 11 insertions(+)
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);
}
