Re: [akpm-mm:mm-new] BUILD SUCCESS WITH UNVERIFIED WARNING e0ffd277b09a7c9f1a436e5f75be37ac490bc59f

On Tue, 11 Aug 2026 16:50:15 -0700 Stanislav Kinsburskii <[email protected]> wrote:

> > Caused by
> > 
> > 	121170831228 ("mm/hmm: add hmm_range_fault_unlocked_timeout() for mmap lock-drop support")
> > 
> > 
> > Stanislaw, you've previously said that this is a can't-happen, but boy
> > I'm getting tired of seeing this warning report.  Would the below change
> > hurt anything?  I can't immediately think of a cost-free way of doing
> > this.
> > 
> 
> I think this change doesn't do any harm.
> Perhaps it worth a WARN_ON_ONCE to expose a wrong fault handler
> behavior?

Like this?

		if (ret & (VM_FAULT_COMPLETED | VM_FAULT_RETRY)) {
			if (hmm_vma_walk->locked)    /* needed by sparse */
				*hmm_vma_walk->locked = false;
			else
				WARN_ON_ONCE(1);    /* broken fault handler */
			return HMM_FAULT_UNLOCKED;
		}