Re: [GIT PULL] Networking for v6.8-rc7

[Jakub Kicinski]

On Thu, 29 Feb 2024 12:56:21 -0800 Linus Torvalds wrote:
> On Thu, 29 Feb 2024 at 12:39, Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
> > A few hours late, the commit on top fixes an odd "rcu_dereference()
> > needs to know full type" build issue I can't repro..  
> 
> Ugfh. That change literally makes a single load instruction be a
> function call. Pretty sad, particularly with all the crazy CPU
> mitigations causing that to be even more expensive than it is already.
> 
> I really don't see how that error can happen, it sounds very odd.
> 
> Oh well.

Another mysterious report was:

include/linux/dpll.h:179:1: warning: control reaches end of non-void function [-Wreturn-type]
https://lore.kernel.org/all/202403010245.MXVdcekk-lkp@xxxxxxxxx/

which I also don't see how since the code as of the commit used was:

   173	static inline struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
   174	{
   175	#if IS_ENABLED(CONFIG_DPLL)
   176		return rcu_dereference_rtnl(dev->dpll_pin);
   177	#else
   178		return NULL;
   179	#endif
   180	}

We'll rejig this in net-next, all the caller does is pass the result
to another function.