[PATCH 1/3] spi: fix resource leak for drivers without .remove callback

From: Uwe Kleine-König
Date: Thu Nov 19 2020 - 10:21:38 EST


Consider an spi driver with a .probe but without a .remove callback (e.g.
rtc-ds1347). The function spi_drv_probe() is called to bind a device and
so some init routines like dev_pm_domain_attach() are used. As there is
no remove callback spi_drv_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 either both or none of the functions and make
them handle the callback not being set.

Fixes: 33cf00e57082 ("spi: attach/detach SPI device to the ACPI power domain")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
drivers/spi/spi.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 0cab239d8e7f..5bdc66f08ee1 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -405,9 +405,11 @@ static int spi_drv_probe(struct device *dev)
if (ret)
return ret;

- ret = sdrv->probe(spi);
- if (ret)
- dev_pm_domain_detach(dev, true);
+ if (sdrv->probe) {
+ ret = sdrv->probe(spi);
+ if (ret)
+ dev_pm_domain_detach(dev, true);
+ }

return ret;
}
@@ -415,9 +417,10 @@ static int spi_drv_probe(struct device *dev)
static int spi_drv_remove(struct device *dev)
{
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
- int ret;
+ int ret = 0;

- ret = sdrv->remove(to_spi_device(dev));
+ if (sdrv->remove)
+ ret = sdrv->remove(to_spi_device(dev));
dev_pm_domain_detach(dev, true);

return ret;
@@ -442,10 +445,10 @@ int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
{
sdrv->driver.owner = owner;
sdrv->driver.bus = &spi_bus_type;
- if (sdrv->probe)
+ if (sdrv->probe || sdrv->remove) {
sdrv->driver.probe = spi_drv_probe;
- if (sdrv->remove)
sdrv->driver.remove = spi_drv_remove;
+ }
if (sdrv->shutdown)
sdrv->driver.shutdown = spi_drv_shutdown;
return driver_register(&sdrv->driver);

base-commit: 09162bc32c880a791c6c0668ce0745cf7958f576
prerequisite-patch-id: 81a6cc3e9e110aa4427c029e2f950f83a91c9a22
prerequisite-patch-id: 9c80bf49810461fd0e1a35b0a134675bc4333678
prerequisite-patch-id: bfb025de56c9e52ea068686a64f5f5ed6b29ab4f
prerequisite-patch-id: b490ddb3c51a92f058e252faf89c4cadd4a0e415
prerequisite-patch-id: 9c94ab8c9f66d0330549d1ecdc18e6ac97f8a7e4
--
2.28.0