On Mon, Aug 29, 2022 at 12:09 AM Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote: > > On Sun, 28 Aug 2022, Li Zhong wrote: > > > On Fri, Aug 26, 2022 at 9:01 AM Andy Shevchenko > > <andy.shevchenko@xxxxxxxxx> wrote: > > > > > > On Fri, Aug 26, 2022 at 11:38 AM Li Zhong <floridsleeves@xxxxxxxxx> wrote: > > > > > > > > uart_port_check() will return NULL pointer when state->uart_port is > > > > NULL. Check the return value before dereference it to avoid > > > > null-pointer-dereference error. > > > > > > Have you taken the locking into consideration? > > > If no, please do, if yes, expand your commit message to explain why > > > the current locking scheme doesn't prevent an error from happening. > > > > > > > The locking is taken into consideration but these three checks do not need to > > unlock in error-handling because unlock() will be called in the callers. Will > > add the comment in v2 patch. > > I think he meant you should indicate why the current locking doesn't cover > the case you're fixing, not whether this function should call unlock() or > not. > Thanks for clarifications. The locking does not guarantee the return value of uart_port_check() is not NULL. Actually in line 773 of this file (drivers/tty/serial/serial_core.c), uart_port_check() is also called in critical section but still there is check on whether the return value is NULL. > -- > i. >
