[PATCH V8 44/44] devdax: Enable stray access protection

[ira . weiny]

From: Ira Weiny <ira.weiny@xxxxxxxxx>

Device dax is primarily accessed through user space and kernel access is
controlled through the kmap interfaces.

Now that all valid kernel initiated access to dax devices have been
accounted for, turn on PGMAP_PKEYS_PROTECT for device dax.

Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>

---
Changes for V8
	Rebase to 5.17-rc1
	Use pgmap_protection_available()
	s/PGMAP_PKEYS_PROTECT/PGMAP_PROTECTION/
---
 drivers/dax/device.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index d33a0613ed0c..cee375ef2cac 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -452,6 +452,8 @@ int dev_dax_probe(struct dev_dax *dev_dax)
 	if (dev_dax->align > PAGE_SIZE)
 		pgmap->vmemmap_shift =
 			order_base_2(dev_dax->align >> PAGE_SHIFT);
+	if (pgmap_protection_available())
+		pgmap->flags |= PGMAP_PROTECTION;
 	addr = devm_memremap_pages(dev, pgmap);
 	if (IS_ERR(addr))
 		return PTR_ERR(addr);
-- 
2.31.1