diff options
| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-05-17 22:48:17 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-05-17 22:54:22 +0200 |
| commit | 63d22063073b0ab46d1e06fe633fb5de8f5c58e1 (patch) | |
| tree | a5bafd332a3436b98e5ae892d1708f73065f836b | |
| parent | 30d7891ae903d1e2903033a3df453d7533011076 (diff) | |
| download | linux-63d22063073b0ab46d1e06fe633fb5de8f5c58e1.tar.gz | |
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>
| -rw-r--r-- | drivers/rtc/rtc-tps6586x.c | 14 |
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: |