On Mon, May 15, 2023 at 05:08:37PM +0800, Baoquan He wrote: > Several architectures has done checking if slab if available in > ioremap_prot(). In fact it should be done in generic ioremap_prot() > since on any architecutre, slab allocator must be available before > get_vm_area_caller() and vunmap() are used. > > Add the checking into generic_ioremap_prot(). Should we add a WARN_ON/WARN_ON_ONCE to aid debugging? Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@xxxxxx>