Re: [PATCH v2 3/4] cxl/pci: Fix sanitize notifier setup

[Dan Williams <dan.j.williams@intel.com>]

Davidlohr Bueso wrote:
> On Fri, 29 Sep 2023, Dan Williams wrote:
> 
> >+static int cxl_sanitize_setup_notifier(struct cxl_memdev *cxlmd)
> >+{
> >+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> >+	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
> >+	struct device *dev = cxlds->dev;
> 
> This wants to be dev = &cxlmd->dev;

No, the notifier needs to be torn down in the cxl_pci teardown path. If
cxlmd->dev was the devm operations host then this notifier would need to
be setup from the cxl_mem driver, not cxl_pci. The teardown order of
cxl_pci ends with @cxlds->dev as the devm host ends up as:

cxl_sanitize_teardown_notifier()
cxl_memdev_unregister()

...otherwise if the @cxlmd->dev is used then the devm callback may not
fire until device_release() time since it is possible that the cxl_mem
driver never attaches to trigger the typical devm action around
->remove() time.

> >+	struct kernfs_node *sec;
> >+
> >+	if (!test_bit(CXL_SEC_ENABLED_SANITIZE, mds->security.enabled_cmds))
> >+		return 0;
> >+
> >+	sec = sysfs_get_dirent(dev->kobj.sd, "security");
> >+	if (!sec) {
> >+		dev_err(dev, "sanitize notification setup failure\n");
> 
> Nit: Should the error message differ from the next one? Maybe s/sanitize/security?

Maybe, but these things will likely never fire, as devm_cxl_add_memdev()
would have failed before getting here. Maybe just delete them?