powerpc/32: prepare shadow area for KASAN

This patch prepares a shadow area for KASAN.

The shadow area will be at the top of the kernel virtual
memory space above the fixmap area and will occupy one
eighth of the total kernel virtual memory space.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/ptdump/ptdump.c

@@ -100,6 +100,10 @@ static struct addr_marker address_markers[] = {
 #endif
 	{ 0,	"Fixmap start" },
 	{ 0,	"Fixmap end" },
+#endif
+#ifdef CONFIG_KASAN
+	{ 0,	"kasan shadow mem start" },
+	{ 0,	"kasan shadow mem end" },
 #endif
 	{ -1,	NULL },
 };
@@ -323,6 +327,10 @@ static void populate_markers(void)
 #endif
 	address_markers[i++].start_address = FIXADDR_START;
 	address_markers[i++].start_address = FIXADDR_TOP;
+#ifdef CONFIG_KASAN
+	address_markers[i++].start_address = KASAN_SHADOW_START;
+	address_markers[i++].start_address = KASAN_SHADOW_END;
+#endif
 #endif /* CONFIG_PPC64 */
 }