[Xen-devel] [PATCH]: Fix fully-virtualized core dumps for 32-bit guests

[Chris Lalancette <clalance@xxxxxxxxxx>]

All,
     Attached is a simple patch to fix core dumps for 32-bit guests running on
32-bit HV/dom0.  The problem ends up being a cast in the libxc dumping code;
basically in xc_core_x86.c, p2m_size is a ulong, and in the case of a 32-bit FV
guest 0xFFFFF is returned from xc_memory_op() in nr_gpfns.  However, 1 is then
added.  This means that when we are doing the map->size calculations, we have
0x100000 << 12, which yields 0, which is then stored in the uint64 map->size.
The simple fix is to cast p2m_size up to 64-bits first, then do the shift, then
store it into map->size.
     The patch is against xen-3.1, but should apply to current xen-unstable.

Signed-off-by: Chris Lalancette <clalance@xxxxxxxxxx>

diff -r c0b0974fb055 tools/libxc/xc_core_x86.c
--- a/tools/libxc/xc_core_x86.c Fri May 18 16:59:32 2007 +0100
+++ b/tools/libxc/xc_core_x86.c Mon Jun 11 14:18:19 2007 -0400
@@ -49,7 +49,7 @@ xc_core_arch_memory_map_get(int xc_handl
     }
 
     map->addr = 0;
-    map->size = p2m_size << PAGE_SHIFT;
+    map->size = ((uint64_t)p2m_size) << PAGE_SHIFT;
 
     *mapp = map;
     *nr_entries = 1;

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