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authorAlexandre Belloni <alexandre.belloni@bootlin.com>2018-05-17 22:48:17 +0200
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2018-05-17 22:54:22 +0200
commit63d22063073b0ab46d1e06fe633fb5de8f5c58e1 (patch)
treea5bafd332a3436b98e5ae892d1708f73065f836b /drivers/rtc
parent30d7891ae903d1e2903033a3df453d7533011076 (diff)
rtc: tps6586x: fix possible race condition
The probe function is not allowed to fail after the RTC is registered 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* */ Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-tps6586x.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/rtc/rtc-tps6586x.c b/drivers/rtc/rtc-tps6586x.c
index 46a19adf9a96..9b741143f131 100644
--- a/drivers/rtc/rtc-tps6586x.c
+++ b/drivers/rtc/rtc-tps6586x.c
@@ -276,14 +276,15 @@ static int tps6586x_rtc_probe(struct platform_device *pdev)
device_init_wakeup(&pdev->dev, 1);
platform_set_drvdata(pdev, rtc);
- rtc->rtc = devm_rtc_device_register(&pdev->dev, dev_name(&pdev->dev),
- &tps6586x_rtc_ops, THIS_MODULE);
+ rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc->rtc)) {
ret = PTR_ERR(rtc->rtc);
- dev_err(&pdev->dev, "RTC device register: ret %d\n", ret);
+ dev_err(&pdev->dev, "RTC allocate device: ret %d\n", ret);
goto fail_rtc_register;
}
+ rtc->rtc->ops = &tps6586x_rtc_ops;
+
ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
tps6586x_rtc_irq,
IRQF_ONESHOT,
@@ -294,6 +295,13 @@ static int tps6586x_rtc_probe(struct platform_device *pdev)
goto fail_rtc_register;
}
disable_irq(rtc->irq);
+
+ ret = rtc_register_device(rtc->rtc);
+ if (ret) {
+ dev_err(&pdev->dev, "RTC device register: ret %d\n", ret);
+ goto fail_rtc_register;
+ }
+
return 0;
fail_rtc_register: