[patch] 2.5.43 export _end

[Keith Owens]

Some programs such as ps, lkcd and others need to validate that
System.map matches the kernel.  Comparing all symbol names from ksyms
against map breaks badly when faced with function descriptors (ia64 has
hundreds of mismatches because of function descriptors).  lkcd attempts
to solve this problem by adding kernel_magic which contains the value
of _end, but that requires /dev/kmem access to read kernel_magic.

Trivial fix - export _end.  Every arch *lds* file defines _end.
No special access is required to match ksyms _end against System.map
_end.

Index: 43.1/kernel/ksyms.c
--- 43.1/kernel/ksyms.c Wed, 16 Oct 2002 14:25:21 +1000 kaos (linux-2.5/w/d/18_ksyms.c 1.22.1.31 444)
+++ 43.1(w)/kernel/ksyms.c Thu, 17 Oct 2002 12:16:14 +1000 kaos (linux-2.5/w/d/18_ksyms.c 1.22.1.31 444)
@@ -602,3 +602,7 @@ EXPORT_SYMBOL(__per_cpu_offset);
 
 /* debug */
 EXPORT_SYMBOL(dump_stack);
+
+/* To match ksyms with System.map */
+extern const char _end[];
+EXPORT_SYMBOL(_end);