From: Dan Williams <dan.j.williams@xxxxxxxxx>
commit 0d9e734018d70cecf79e2e4c6082167160a0f13f upstream.
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")
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Link: https://lore.kernel.org/r/166752183055.947915.17681995648556534844.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cxl/core/region.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1556,8 +1556,19 @@ static struct cxl_region *to_cxl_region(
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);
}
