[PATCH 4.19 138/247] amba: Fix resource leak for drivers without .remove

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 15:48:52 EST


From: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>

[ Upstream commit de5d7adb89367bbc87b4e5ce7afe7ae9bd86dc12 ]

Consider an amba driver with a .probe but without a .remove callback (e.g.
pl061_gpio_driver). The function amba_probe() is called to bind a device
and so dev_pm_domain_attach() and others are called. As there is no remove
callback amba_remove() isn't called at unbind time however and so calling
dev_pm_domain_detach() is missed and the pm domain keeps active.

To fix this always use the core driver callbacks and handle missing amba
callbacks there. For probe refuse registration as a driver without probe
doesn't make sense.

Fixes: 7cfe249475fd ("ARM: AMBA: Add pclk support to AMBA bus infrastructure")
Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Link: https://lore.kernel.org/r/20210126165835.687514-2-u.kleine-koenig@xxxxxxxxxxxxxx
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/amba/bus.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 41b706403ef72..2380ebd9b7fda 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -284,10 +284,11 @@ static int amba_remove(struct device *dev)
{
struct amba_device *pcdev = to_amba_device(dev);
struct amba_driver *drv = to_amba_driver(dev->driver);
- int ret;
+ int ret = 0;

pm_runtime_get_sync(dev);
- ret = drv->remove(pcdev);
+ if (drv->remove)
+ ret = drv->remove(pcdev);
pm_runtime_put_noidle(dev);

/* Undo the runtime PM settings in amba_probe() */
@@ -304,7 +305,9 @@ static int amba_remove(struct device *dev)
static void amba_shutdown(struct device *dev)
{
struct amba_driver *drv = to_amba_driver(dev->driver);
- drv->shutdown(to_amba_device(dev));
+
+ if (drv->shutdown)
+ drv->shutdown(to_amba_device(dev));
}

/**
@@ -317,12 +320,13 @@ static void amba_shutdown(struct device *dev)
*/
int amba_driver_register(struct amba_driver *drv)
{
- drv->drv.bus = &amba_bustype;
+ if (!drv->probe)
+ return -EINVAL;

-#define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn
- SETFN(probe);
- SETFN(remove);
- SETFN(shutdown);
+ drv->drv.bus = &amba_bustype;
+ drv->drv.probe = amba_probe;
+ drv->drv.remove = amba_remove;
+ drv->drv.shutdown = amba_shutdown;

return driver_register(&drv->drv);
}
--
2.27.0