From: balrog <balrog@c046a42c-6fe2-441c-8c8c-71466251a162>
Date: Tue, 28 Oct 2008 10:24:11 +0000 (+0000)
Subject: page_check_range: fix wrap around test (Lauro Ramos Venancio).
X-Git-Tag: qemu-xen-4.3.0-rc1~10716
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=55f280c90ed7288b392fcf718efc2d3caca11e91;p=qemu-upstream-unstable.git

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.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5563 c046a42c-6fe2-441c-8c8c-71466251a162
---

diff --git a/exec.c b/exec.c
index f1fcec833..697a19eb2 100644
--- a/exec.c
+++ b/exec.c
@@ -2081,12 +2081,13 @@ int page_check_range(target_ulong start, target_ulong len, int flags)
     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 )