xsplice: Prevent new symbols duplicating core symbols

When loading patches, the code prevents loading a patch containing a new
symbol that duplicates a symbol from another loaded patch. However, the
check should also prevent loading a new symbol that duplicates a symbol
from the core hypervisor.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>

xen/common/xsplice.c

@@ -748,7 +748,8 @@ static int build_symbol_table(struct payload *payload,
 
         if ( !found )
         {
-            if ( xsplice_symbols_lookup_by_name(symtab[i].name) )
+            if ( symbols_lookup_by_name(symtab[i].name) ||
+                 xsplice_symbols_lookup_by_name(symtab[i].name) )
             {
                 dprintk(XENLOG_ERR, XSPLICE "%s: duplicate new symbol: %s\n",
                         elf->name, symtab[i].name);