mm: don't allow executable ioremap mappings

There is no need to execute from iomem (and most platforms it is
impossible anyway), so add the pgprot_nx() call similar to vmap.

Link: https://lkml.kernel.org/r/20210824091259.1324527-3-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/vmalloc.c

@@ -316,7 +316,7 @@ int ioremap_page_range(unsigned long addr, unsigned long end,
 {
 	int err;
 
-	err = vmap_range_noflush(addr, end, phys_addr, prot,
+	err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot),
 				 ioremap_max_page_shift);
 	flush_cache_vmap(addr, end);
 	return err;