lto: Handle LTO common symbols in module loader
Here is the workaround I made for having the kernel not reject modules
built with -flto. The clean solution would be to get the compiler to not
emit the symbol. Or if it has to emit the symbol, then emit it as
initialized data but put it into a comdat/linkonce section.
Minor tweaks by AK over Joe's patch.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391846481-31491-5-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/kernel/module.c b/kernel/module.c
index d24fcf2..b99e801 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1948,6 +1948,10 @@
switch (sym[i].st_shndx) {
case SHN_COMMON:
+ /* Ignore common symbols */
+ if (!strncmp(name, "__gnu_lto", 9))
+ break;
+
/* We compiled with -fno-common. These are not
supposed to happen. */
pr_debug("Common symbol: %s\n", name);