On 4/5/21 5:59 AM, eichest@xxxxxxxxx wrote: > From: Stefan Eichenberger <eichest@xxxxxxxxx> > > If the WDIOF_PRETIMEOUTE flag is not set when registering the device the WDIOF_PRETIMEOUT > driver will not show the sysfs entries or register the default governor. > By moving the registering after the decision whether pretimeout is > supported this gets fixed. > This is problematic. If the notifier is called and the watchdog is not yet registered, it will call watchdog_notify_pretimeout on an unregistered watchdog device which would crash the system. The notifier function needs to handle that situation. This is for both registration and removal: On removal, the watchdog device would be unregistered first (because of the use of devm_ functions) and, again, the notifier could be called on an unregistered watchdog device. > Signed-off-by: Stefan Eichenberger <eichest@xxxxxxxxx> > --- > drivers/watchdog/imx_sc_wdt.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c > index e9ee22a7cb45..eddb1ae630e0 100644 > --- a/drivers/watchdog/imx_sc_wdt.c > +++ b/drivers/watchdog/imx_sc_wdt.c > @@ -183,10 +183,6 @@ static int imx_sc_wdt_probe(struct platform_device *pdev) > watchdog_stop_on_reboot(wdog); > watchdog_stop_on_unregister(wdog); > > - ret = devm_watchdog_register_device(dev, wdog); > - if (ret) > - return ret; > - > ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, > SC_IRQ_WDOG, > true); > @@ -213,6 +209,10 @@ static int imx_sc_wdt_probe(struct platform_device *pdev) > else > dev_warn(dev, "Add action failed, pretimeout NOT supported\n"); > > + ret = devm_watchdog_register_device(dev, wdog); > + if (ret) > + return ret; > + > return 0; This is equivalent to just "return ret;". > } > >
