ANDROID: 16K: Ensure mseal start and len are 16kB multiples

For 16kB page size emulation in x86_64, ensure that mseal()
operates on regions that are __PAGE_SIZE multiple sized and
aligned.

Bug: 383389337
Bug: 356480574
Change-Id: I0bc25a0090637b51558050764010a6e24275a2bb
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>

mm/mseal.c

@@ -12,6 +12,7 @@
 #include <linux/mm.h>
 #include <linux/mm_inline.h>
 #include <linux/mmu_context.h>
+#include <linux/page_size_compat.h>
 #include <linux/syscalls.h>
 #include <linux/sched.h>
 #include "internal.h"
@@ -222,10 +223,10 @@ int do_mseal(unsigned long start, size_t len_in, unsigned long flags)
 		return ret;
 
 	start = untagged_addr(start);
-	if (!PAGE_ALIGNED(start))
+	if (!__PAGE_ALIGNED(start))
 		return -EINVAL;
 
-	len = PAGE_ALIGN(len_in);
+	len = __PAGE_ALIGN(len_in);
 	/* Check to see whether len was rounded up from small -ve to zero. */
 	if (len_in && !len)
 		return -EINVAL;