Re: [PATCH net 1/2] selftests: netfilter: fix udpclash tool hang

[Florian Westphal <fw@strlen.de>]

Jakub Kicinski <kuba@kernel.org> wrote:
> On Tue,  2 Sep 2025 20:58:54 +0200 Florian Westphal wrote:
> > Yi Chen reports that 'udpclash' loops forever depending on compiler
> > (and optimization level used); while (x == 1) gets optimized into
> > for (;;).  Switch to stdatomic to prevent this.
> 
> gcc version 15.1.1 (F42) w/ whatever flags kselftests use appear to be
> unaware of this macro:
> 
> udpclash.c:33:26: error: implicit declaration of function ‘ATOMIC_VAR_INIT’; did you mean ‘ATOMIC_FLAG_INIT’? [-Wimplicit-function-declaration]
>    33 | static atomic_int wait = ATOMIC_VAR_INIT(1);
>       |                          ^~~~~~~~~~~~~~~
>       |                          ATOMIC_FLAG_INIT
> udpclash.c:33:26: error: initializer element is not constant
> Could you perhaps use volatile instead?

That works too.  I'll send a new PR tomorrow, its late here.