validation/sm_locking6.c

   1 int __raw_local_irq_save();
   2 int _spin_trylock(int x);
   3 int raw_local_irq_restore(flags);
   4
   5 #define spin_trylock_irqsave(lock, flags) \
   6 ({ \
   7         (flags) = __raw_local_irq_save(); \
   8         _spin_trylock(lock) ? 1 : ({ raw_local_irq_restore(flags);  0; }); \
   9 })
  10
  11 void _spin_unlock_irqrestore(int lock, int flags);
  12
  13 int zzz;
  14
  15 void func (void)
  16 {
  17         int lock = 1;
  18         int flags = 1;
  19
  20         if (!spin_trylock_irqsave(lock, flags))
  21                 return;
  22         _spin_unlock_irqrestore(lock, flags);
  23         if (zzz)
  24                 return;
  25         if (spin_trylock_irqsave(lock, flags))
  26                 return;
  27         return;
  28 }
  29 /*
  30  * check-name: Smatch locking #6
  31  * check-command: smatch -p=kernel -DCONFIG_SMP=y sm_locking6.c
  32  *
  33  * check-output-start
  34 sm_locking6.c:27 func() warn: inconsistent returns 'flags'.
  35   Locked on  : 26
  36   Unlocked on: 21,24,27
  37 sm_locking6.c:27 func() warn: inconsistent returns 'lock'.
  38   Locked on  : 26
  39   Unlocked on: 24,27
  40  * check-output-end
  41  */