Kbuild, lto: Handle basic LTO in modpost

- Don't warn about LTO marker symbols. modpost runs before
the linker, so the module is not necessarily LTOed yet.
- Don't complain about .gnu.lto* sections

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391846481-31491-13-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index f91dd4565b81..63804a16ba9f 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -623,7 +623,10 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
 
         switch (sym->st_shndx) {
         case SHN_COMMON:
-                warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
+                if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
+                        /* Should warn here, but modpost runs before the linker */
+                } else
+                        warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
                 break;
         case SHN_UNDEF:
                 /* undefined symbol */
@@ -849,6 +852,7 @@ static const char *section_white_list[] =
         ".xt.lit",         /* xtensa */
         ".arcextmap*",                  /* arc */
         ".gnu.linkonce.arcext*",        /* arc : modules */
+        ".gnu.lto*",
         NULL
 };