Re: [PATCH v1 1/1] serial: core: make static analyzer happy about locks

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Nov 10, 2016 at 04:59:54PM +0200, Andy Shevchenko wrote:
> On Thu, 2016-11-10 at 14:59 +0100, Greg Kroah-Hartman wrote:
> > On Thu, Nov 03, 2016 at 06:26:57PM +0200, Andy Shevchenko wrote:
> > > Static analyzer can not see balanced locking if the lock is acquired
> > > and
> > > released conditionally. Add __acquire() and __release() markings in
> > > the right
> > > locations so that sparse isn't tripped up on the conditional
> > > locking.
> > > 
> > > drivers/tty/serial/serial_core.c:131:17: warning: context imbalance
> > > in 'uart_stop' - unexpected unlock
> > > include/linux/spinlock.h:362:9: warning: context imbalance in
> > > 'uart_start' - unexpected unlock
> > > include/linux/spinlock.h:362:9: warning: context imbalance in
> > > 'uart_put_char' - unexpected unlock
> > > include/linux/spinlock.h:362:9: warning: context imbalance in
> > > 'uart_write' - unexpected unlock
> > > include/linux/spinlock.h:362:9: warning: context imbalance in
> > > 'uart_write_room' - unexpected unlock
> > > include/linux/spinlock.h:362:9: warning: context imbalance in
> > > 'uart_chars_in_buffer' - unexpected unlock
> > > include/linux/spinlock.h:362:9: warning: context imbalance in
> > > 'uart_flush_buffer' - unexpected unlock
> > > 
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > > ---
> > >  drivers/tty/serial/serial_core.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/drivers/tty/serial/serial_core.c
> > > b/drivers/tty/serial/serial_core.c
> > > index f2303f3..ff90c8e 100644
> > > --- a/drivers/tty/serial/serial_core.c
> > > +++ b/drivers/tty/serial/serial_core.c
> > > @@ -82,6 +82,8 @@ static inline void uart_port_deref(struct
> > > uart_port *uport)
> > >  		struct uart_port *__uport = uart_port_ref(state);	
> > > \
> > >  		if (__uport)					
> > > 	\
> > >  			spin_lock_irqsave(&__uport->lock, flags);	
> > > \
> > > +		else						
> > > 	\
> > > +			__acquire(&__uport->lock);			
> > > \
> > 
> > That doesn't make much logical sense.  Yes, I know __acquire is just a
> > crazy macro, but really, look at what you just wrote and tell me that
> > someone who doesn't know what __acquire does, would instantly think
> > this
> > is a null pointer dereference.
> > 
> > Please fix.
> 
> Do you mean add comments here in the code?

Huh?

No, fix the macro to make sense!!!
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux