ARM: initrd: disable initrds outside of memory

We can't cope with initrds outside of memory, so check that the
initrd is within some declared memory to the kernel before using
it.  Otherwise we're likely to OOPS during boot.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/init.c

@@ -330,6 +330,12 @@ void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
 	memblock_reserve(__pa(_stext), _end - _stext);
 #endif
 #ifdef CONFIG_BLK_DEV_INITRD
+	if (phys_initrd_size &&
+	    !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
+		pr_err("INITRD: 0x%08lx+0x%08lx is not a memory region - disabling initrd\n",
+		       phys_initrd_start, phys_initrd_size);
+		phys_initrd_start = phys_initrd_size = 0;
+	}
 	if (phys_initrd_size &&
 	    memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
 		pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region - disabling initrd\n",