[PATCH 01/15] mm: various small mmap_prepare cleanups

[Andrew Morton]

On Thu, 12 Mar 2026 20:27:16 +0000 "Lorenzo Stoakes (Oracle)" <ljs at kernel.org> wrote:

> +int mmap_action_prepare(struct vm_area_desc *desc,
> +			struct mmap_action *action)
> +
>  {
>  	switch (action->type) {
>  	case MMAP_NOTHING:
> -		break;
> +		return 0;
>  	case MMAP_REMAP_PFN:
> -		remap_pfn_range_prepare(desc, action->remap.start_pfn);
> -		break;
> +		return remap_pfn_range_prepare(desc, action);
>  	case MMAP_IO_REMAP_PFN:
> -		io_remap_pfn_range_prepare(desc, action->remap.start_pfn,
> -					   action->remap.size);
> -		break;
> +		return io_remap_pfn_range_prepare(desc, action);
>  	}
>  }
>  EXPORT_SYMBOL(mmap_action_prepare);

hm, was this the correct version?

mm/util.c: In function 'mmap_action_prepare':
mm/util.c:1451:1: error: control reaches end of non-void function [-Werror=return-type]
 1451 | }

--- a/mm/util.c~mm-various-small-mmap_prepare-cleanups-fix
+++ a/mm/util.c
@@ -1356,6 +1356,8 @@ int mmap_action_prepare(struct vm_area_d
 		return remap_pfn_range_prepare(desc, action);
 	case MMAP_IO_REMAP_PFN:
 		return io_remap_pfn_range_prepare(desc, action);
+	default:
+		BUG();
 	}
 }
 EXPORT_SYMBOL(mmap_action_prepare);
_