[PATCH] kbuild: modpost needs to cope with new glibc elf header on sparc

Recently a change in the glibc elf.h header has been introduced causing
modpost to spawn tons of warnings (like the one below) building the kernel
on sparc:

[SNIP]
*** Warning: "current_thread_info_reg" [net/sunrpc/auth_gss/auth_rpcgss.ko] undefined!
*** Warning: "" [net/sunrpc/auth_gss/auth_rpcgss.ko] undefined!
*** Warning: "" [net/sunrpc/auth_gss/auth_rpcgss.ko] undefined!
[SNIP]

Ben Collins discovered that the STT_REGISTERED definition in glibc did change
and that this change needs to be propagated to modpost.

glibc change:
-#define STT_REGISTER   13              /* Global register reserved to app. */
+#define STT_SPARC_REGISTER     13      /* Global register reserved to app. */

I did and tested this simple patch to maintain compatibility with newer (>= 2.3.4)
and older (<= 2.3.2) glibc.
Signed-off-by: Fabio M. Di Nitto <fabbione@fabbione.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/mod/modpost.c

@@ -359,11 +359,16 @@ handle_modversions(struct module *mod, struct elf_info *info,
 		/* ignore __this_module, it will be resolved shortly */
 		if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
 			break;
-#ifdef STT_REGISTER
+/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
+#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
+/* add compatibility with older glibc */
+#ifndef STT_SPARC_REGISTER
+#define STT_SPARC_REGISTER STT_REGISTER
+#endif
 		if (info->hdr->e_machine == EM_SPARC ||
 		    info->hdr->e_machine == EM_SPARCV9) {
 			/* Ignore register directives. */
-			if (ELF_ST_TYPE(sym->st_info) == STT_REGISTER)
+			if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 				break;
 		}
 #endif