On 19 Oct 2022 16:24, Andrew Burgess via Gdb-patches wrote:
> When calling semctl with an GETVAL action, the 'union semun' argument
> is unused.
> 
> Rather than passing an uninitialized variable (as we currently do),
> just pass the integer 0.  This silences some compiler warnings, and is
> just as correct (given the argument is ignored).
> 
> To be honest, it might be the case that the argument is not needed at
> all, however, I'm a little nervous to make this change as the amount
> of testing I can do of this code is limited.  Every example I found
> online for a semctl/GETVAL call did pass the final argument, so that's
> what I've continued to do.

the semctl prototype is:
	int semctl(int semid, int semnum, int cmd, ...);

i would just delete the 4th arg, but if you really want to keep the 0, OK.
-mike