use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages

After all that's what they are intended for.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 9e3581f..0dac75e 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -993,7 +993,7 @@
 			 */
 			safe_copy_page(buffer, s_page);
 			dst = kmap_atomic(d_page, KM_USER0);
-			memcpy(dst, buffer, PAGE_SIZE);
+			copy_page(dst, buffer);
 			kunmap_atomic(dst, KM_USER0);
 		} else {
 			safe_copy_page(page_address(d_page), s_page);
@@ -1687,7 +1687,7 @@
 		memory_bm_position_reset(&orig_bm);
 		memory_bm_position_reset(&copy_bm);
 	} else if (handle->cur <= nr_meta_pages) {
-		memset(buffer, 0, PAGE_SIZE);
+		clear_page(buffer);
 		pack_pfns(buffer, &orig_bm);
 	} else {
 		struct page *page;
@@ -1701,7 +1701,7 @@
 			void *kaddr;
 
 			kaddr = kmap_atomic(page, KM_USER0);
-			memcpy(buffer, kaddr, PAGE_SIZE);
+			copy_page(buffer, kaddr);
 			kunmap_atomic(kaddr, KM_USER0);
 			handle->buffer = buffer;
 		} else {
@@ -1984,7 +1984,7 @@
 		void *dst;
 
 		dst = kmap_atomic(last_highmem_page, KM_USER0);
-		memcpy(dst, buffer, PAGE_SIZE);
+		copy_page(dst, buffer);
 		kunmap_atomic(dst, KM_USER0);
 		last_highmem_page = NULL;
 	}
@@ -2270,9 +2270,9 @@
 
 	kaddr1 = kmap_atomic(p1, KM_USER0);
 	kaddr2 = kmap_atomic(p2, KM_USER1);
-	memcpy(buf, kaddr1, PAGE_SIZE);
-	memcpy(kaddr1, kaddr2, PAGE_SIZE);
-	memcpy(kaddr2, buf, PAGE_SIZE);
+	copy_page(buf, kaddr1);
+	copy_page(kaddr1, kaddr2);
+	copy_page(kaddr2, buf);
 	kunmap_atomic(kaddr2, KM_USER1);
 	kunmap_atomic(kaddr1, KM_USER0);
 }