[PATCH]i386: fix overflow in vmap on an x86 system which has morethan 4GB memory.

[Anatoli Antonovitch]

Description
(max_mapnr << PAGE_SHIFT) would overflow on an x86 system which has more
than 4GB memory, and hence cause vmap to fail every time.


Signed-off-by: Michael Chen <micche@xxxxxxx>

Patch
diff -Nur linux-2.4.21-40.EL/mm/vmalloc.c
linux-2.4.21-40.EL.diff/mm/vmalloc.c
--- linux-2.4.21-40.EL/mm/vmalloc.c     2006-02-02 21:13:20.000000000
-0600
+++ linux-2.4.21-40.EL.diff/mm/vmalloc.c        2006-09-04
11:29:33.000000000 -0500
@@ -298,8 +298,8 @@
        struct vm_struct *area;
        unsigned long size = count << PAGE_SHIFT;
 
-       if (!size || size > (max_mapnr << PAGE_SHIFT))
-               return NULL;
+    if (!count || count > max_mapnr)
+        return NULL;
        area = get_vm_area(size, flags);
        if (!area) {
                return NULL;


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