On 29/01/2019 10:10, Phil Elwell wrote: > "cat /sys/kernel/debug/bcm2835_thermal/regset" causes a NULL pointer > dereference in bcm2835_thermal_debugfs. The driver makes use of the > implementation details of the thermal framework to retrieve a pointer > to its private data from a struct thermal_zone_device, and gets it > wrong - leading to the crash. Instead, store its private data as the > drvdata and retrieve the thermal_zone_device pointer from it. > > Fixes: bcb7dd9ef206 ("thermal: bcm2835: add thermal driver for bcm2835 SoC") > > Signed-off-by: Phil Elwell <p...@raspberrypi.org>
Reviewed-by: Daniel Lezcano <daniel.lezc...@linaro.org> One question: do you really want the thermal driver to be loaded as a module ? Don't you want to have it operational as soon as possible instead of waiting the OS to boot and load the kernel module? If a module format is not needed, then the thermal_zone field won't be needed anymore because the 'remove' ops can be removed and the need of the tz field to unregister it disappears. > --- > drivers/thermal/broadcom/bcm2835_thermal.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/drivers/thermal/broadcom/bcm2835_thermal.c > b/drivers/thermal/broadcom/bcm2835_thermal.c > index 720760c..ba39647 100644 > --- a/drivers/thermal/broadcom/bcm2835_thermal.c > +++ b/drivers/thermal/broadcom/bcm2835_thermal.c > @@ -119,8 +119,7 @@ static const struct debugfs_reg32 bcm2835_thermal_regs[] > = { > > static void bcm2835_thermal_debugfs(struct platform_device *pdev) > { > - struct thermal_zone_device *tz = platform_get_drvdata(pdev); > - struct bcm2835_thermal_data *data = tz->devdata; > + struct bcm2835_thermal_data *data = platform_get_drvdata(pdev); > struct debugfs_regset32 *regset; > > data->debugfsdir = debugfs_create_dir("bcm2835_thermal", NULL); > @@ -266,7 +265,7 @@ static int bcm2835_thermal_probe(struct platform_device > *pdev) > > data->tz = tz; > > - platform_set_drvdata(pdev, tz); > + platform_set_drvdata(pdev, data); > > /* > * Thermal_zone doesn't enable hwmon as default, > @@ -290,8 +289,8 @@ static int bcm2835_thermal_probe(struct platform_device > *pdev) > > static int bcm2835_thermal_remove(struct platform_device *pdev) > { > - struct thermal_zone_device *tz = platform_get_drvdata(pdev); > - struct bcm2835_thermal_data *data = tz->devdata; > + struct bcm2835_thermal_data *data = platform_get_drvdata(pdev); > + struct thermal_zone_device *tz = data->tz; > > debugfs_remove_recursive(data->debugfsdir); > thermal_zone_of_sensor_unregister(&pdev->dev, tz); > -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog