Re: [PATCH] serial: core: Fix kmemleak issue for serial core device remove

From: Jiri Slaby
Date: Fri Aug 04 2023 - 05:20:22 EST


On 04. 08. 23, 11:09, Tony Lindgren wrote:
Kmemleak reports issues for serial8250 ports after the hardware specific
driver takes over on boot as noted by Tomi.

The kerneldoc for device_initialize() says we must call device_put()
after calling device_initialize(). We are calling device_put() on the
error path, but are missing it from the device remove path. This causes
release() to never get called for the devices on remove.

Let's add the missing put_device() calls for both serial ctrl and
port devices.

Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Reported-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/tty/serial/serial_base_bus.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
--- a/drivers/tty/serial/serial_base_bus.c
+++ b/drivers/tty/serial/serial_base_bus.c
@@ -99,6 +99,7 @@ void serial_base_ctrl_device_remove(struct serial_ctrl_device *ctrl_dev)
return;
device_del(&ctrl_dev->dev);
+ put_device(&ctrl_dev->dev);
}
struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port,
@@ -174,6 +175,7 @@ void serial_base_port_device_remove(struct serial_port_device *port_dev)
return;
device_del(&port_dev->dev);
+ put_device(&port_dev->dev);

I didn't check the code, but device_unregister()?

--
js
suse labs