On some cpus memcpy() is not appropriate for copying task structs, any more
than copy_page().  For example, on Athlons it uses 3dnow acceleration, which
causes the snapshotted task struct to have the wrong preempt count on resume.

This just replaces the swsusp snapshot memcpy() with an inlined always-safe
version so that hibernation works again on K7 and various other cpus where
such acceleration is used.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

Index: g26/kernel/power/snapshot.c
===================================================================
--- g26.orig/kernel/power/snapshot.c	2006-07-03 10:45:30.000000000 -0700
+++ g26/kernel/power/snapshot.c	2006-07-06 09:33:07.000000000 -0700
@@ -227,11 +227,19 @@ static void copy_data_pages(struct pbe *
 		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
 			if (saveable(zone, &zone_pfn)) {
 				struct page *page;
+				u8 *src, *dest, *last;
+
 				page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
 				BUG_ON(!pbe);
 				pbe->orig_address = (unsigned long)page_address(page);
-				/* copy_page is not usable for copying task structs. */
-				memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE);
+				/* copy_page is not usable for copying task
+				 * structs; neither is memcpy on some cpus.
+				 */
+				dest = (u8 *)pbe->address;
+				last = dest + PAGE_SIZE;
+				src = (u8 *)pbe->orig_address;
+				while (dest != last)
+					*dest++ = *src++;
 				pbe = pbe->next;
 			}
 		}