From: "Scott Parish" <srparish@us.ibm.com>
Subject: [patch] PFN_PHYS PAE overflow (fixes bug 242)
Date: Fri, 14 Oct 2005 17:12:24 +0000
Message-ID: <20051014171223.GK3417@us.ibm.com>
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machine_specific_memory_setup() makes the following call to setup e820:

    add_memory_region(0, PFN_PHYS(max_pfn), E820_RAM);

Since max_pfn is (rightly) an unsigned long, we overflow for the current
definition of PFN_PHYS. Attached is my preferred solution as it will
hopefully avoid similar situations that may come up in the future.

sRp

-- 
Scott Parish
Signed-off-by: srparish@us.ibm.com

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diff -rN -u -p old-xen-build2/linux-2.6-xen-sparse/include/asm-xen/asm-i386/setup.h new-xen-build2/linux-2.6-xen-sparse/include/asm-xen/asm-i386/setup.h
--- old-xen-build2/linux-2.6-xen-sparse/include/asm-xen/asm-i386/setup.h	2005-10-04 19:08:26.000000000 +0000
+++ new-xen-build2/linux-2.6-xen-sparse/include/asm-xen/asm-i386/setup.h	2005-10-14 18:59:42.000000000 +0000
@@ -8,7 +8,7 @@
 
 #define PFN_UP(x)	(((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
 #define PFN_DOWN(x)	((x) >> PAGE_SHIFT)
-#define PFN_PHYS(x)	((x) << PAGE_SHIFT)
+#define PFN_PHYS(x)	((unsigned long long)(x) << PAGE_SHIFT)
 
 /*
  * Reserved space for vmalloc and iomap - defined in asm/page.h

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