[Qemu-devel] [5563] page_check_range: fix wrap around test (Lauro Ramos Venancio).

[Andrzej Zaborowski]

Revision: 5563
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5563
Author:   balrog
Date:     2008-10-28 10:24:11 +0000 (Tue, 28 Oct 2008)

Log Message:
-----------
page_check_range: fix wrap around test (Lauro Ramos Venancio).

Move up the warp around test because line
'end = TARGET_PAGE_ALIGN(start+len);'
can interfere with it.

Modified Paths:
--------------
    trunk/exec.c

Modified: trunk/exec.c
===================================================================
--- trunk/exec.c        2008-10-28 10:21:03 UTC (rev 5562)
+++ trunk/exec.c        2008-10-28 10:24:11 UTC (rev 5563)
@@ -2081,12 +2081,13 @@
     target_ulong end;
     target_ulong addr;
 
+    if (start + len < start)
+        /* we've wrapped around */
+        return -1;
+
     end = TARGET_PAGE_ALIGN(start+len); /* must do before we loose bits in the 
next step */
     start = start & TARGET_PAGE_MASK;
 
-    if( end < start )
-        /* we've wrapped around */
-        return -1;
     for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
         p = page_find(addr >> TARGET_PAGE_BITS);
         if( !p )