[PATCH v3 1/3] thermal: prevent cooling device with no type to be registered

[Wei Wang <wvw@google.com>]

commit 54fa38cc2eda ("thermal: core: prevent zones with no types to be
registered") added logic to prevent thermal zone with empty type to be
registered. Similarly, there are APIs that rely on cdev->type.
This patch prevents cooling device without valid type to be registered.

Signed-off-by: Wei Wang <wvw@google.com>
---
 drivers/thermal/thermal_core.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index d4481cc8958f..974e2d91c30b 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -954,12 +954,22 @@ __thermal_cooling_device_register(struct device_node *np,
 	struct thermal_zone_device *pos = NULL;
 	int result;
 
-	if (type && strlen(type) >= THERMAL_NAME_LENGTH)
+	if (!type || !type[0]) {
+		pr_err("Error: No cooling device type defined\n");
 		return ERR_PTR(-EINVAL);
+	}
+
+	if (strlen(type) >= THERMAL_NAME_LENGTH) {
+		pr_err("Error: Cooling device name over %d chars: %s\n",
+			THERMAL_NAME_LENGTH, type);
+		return ERR_PTR(-EINVAL);
+	}
 
 	if (!ops || !ops->get_max_state || !ops->get_cur_state ||
-	    !ops->set_cur_state)
+	    !ops->set_cur_state) {
+		pr_err("Error: Cooling device missing callbacks: %s\n", type);
 		return ERR_PTR(-EINVAL);
+	}
 
 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 	if (!cdev)
@@ -972,7 +982,7 @@ __thermal_cooling_device_register(struct device_node *np,
 	}
 
 	cdev->id = result;
-	strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
+	strlcpy(cdev->type, type, sizeof(cdev->type));
 	mutex_init(&cdev->lock);
 	INIT_LIST_HEAD(&cdev->thermal_instances);
 	cdev->np = np;
-- 
2.24.0.393.g34dc348eaf-goog