@@ -751,8 +751,7 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
cmos_rtc.dev = dev;
dev_set_drvdata(dev, &cmos_rtc);
- cmos_rtc.rtc = rtc_device_register(driver_name, dev,
- &cmos_rtc_ops, THIS_MODULE);
+ cmos_rtc.rtc = devm_rtc_allocate_device(dev);
if (IS_ERR(cmos_rtc.rtc)) {
retval = PTR_ERR(cmos_rtc.rtc);
goto cleanup0;
@@ -822,6 +821,11 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
goto cleanup2;
}
+ cmos_rtc.rtc->ops = &cmos_rtc_ops;
+ retval = rtc_register_device(cmos_rtc.rtc);
+ if (retval)
+ goto cleanup3;
+
dev_info(dev, "%s%s, %zd bytes nvram%s\n",
!is_valid_irq(rtc_irq) ? "no alarms" :
cmos_rtc.mon_alrm ? "alarms up to one year" :
@@ -833,12 +837,13 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
return 0;
+cleanup3:
+ sysfs_remove_bin_file(&dev->kobj, &nvram);
cleanup2:
if (is_valid_irq(rtc_irq))
free_irq(rtc_irq, cmos_rtc.rtc);
cleanup1:
cmos_rtc.dev = NULL;
- rtc_device_unregister(cmos_rtc.rtc);
cleanup0:
if (RTC_IOMAPPED)
release_region(ports->start, resource_size(ports));
@@ -869,7 +874,6 @@ static void cmos_do_remove(struct device *dev)
hpet_unregister_irq_handler(cmos_interrupt);
}
- rtc_device_unregister(cmos->rtc);
cmos->rtc = NULL;
ports = cmos->iomem;
The probe function is not allowed to fail after registering the RTC because the following may happen: CPU0: CPU1: sys_load_module() do_init_module() do_one_initcall() cmos_do_probe() rtc_device_register() __register_chrdev() cdev->owner = struct module* open("/dev/rtc0") rtc_device_unregister() module_put() free_module() module_free(mod->module_core) /* struct module *module is now freed */ chrdev_open() spin_lock(cdev_lock) cdev_get() try_module_get() module_is_live() /* dereferences already freed struct module* */ Switch to devm_rtc_allocate_device/rtc_register_device to register the rtc as late as possible. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> --- drivers/rtc/rtc-cmos.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)