Re: memcpy() in swsusp (was: Re: [PATCH 2/2] Fix console handling during suspend/resume)

[Dave Jones <davej@redhat.com>]

On Thu, Jul 06, 2006 at 01:44:42PM -0700, David Brownell wrote:
 > 
 > > > Of course it needs fixing ... it's a bug, also a regression.
 > > > 
 > > > My question is where to fix...
 > > 
 > > Well, I meant replacing the memcpy() in copy_data_pages with an open coded
 > > copying loop.  That should be enough to fix the problem.
 > 
 > One like this?  Yes, it works.  The slower speed shouldn't be
 > much of an issue here.  (Though I'm glad that something in RC1
 > has gotten rid of that slowdown in reading/writing snapshots.)

Why not just use __memcpy instead? Which should be safe on all archs
to do the simplest possible memcpy.

Signed-off-by: Dave Jones <davej@redhat.com>

--- linux-2.6/kernel/power/snapshot.c~	2006-07-06 16:56:11.000000000 -0400
+++ linux-2.6/kernel/power/snapshot.c	2006-07-06 16:59:11.000000000 -0400
@@ -230,8 +230,9 @@ static void copy_data_pages(struct pbe *
 				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 */
+				__memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE);
 				pbe = pbe->next;
 			}
 		}
-- 
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