[v4,01/16] x86: remove LTO_REFERENCE_INITCALL()

Commit Message

Luis R. Rodriguez Aug. 19, 2016, 9:32 p.m. UTC

From: "Luis R. Rodriguez" <[e-mail]>

The setup for LTO never made it upstream, and although this has
some users, this is now really old stuff for a gcc 4.7 LTO problem.
We know that at least LTO_REFERENCE_INITCALL() work around can
be removed if LTO is not supported on v4.7 anymore.

As per Andi the DISABLE_LTO and LTO_CFLAGS are still neeeded though.

v3: added to this series, removing LTO_REFERENCE_INITCALL()
    justifies that other future similar macros do not need
    a respective LTO_REFERENCE_INITCALL() on them therefore
    simplifying new code.

Acked-by: Andi Kleen <[e-mail]>
Signed-off-by: Luis R. Rodriguez <[e-mail]>
---
 include/linux/init.h | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

Patch

diff --git a/include/linux/init.h b/include/linux/init.h
index 1e5c131d5c9a..aa662ad80d9c 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -151,23 +151,6 @@  extern bool initcall_debug;
 
 #ifndef __ASSEMBLY__
 
-#ifdef CONFIG_LTO
-/* Work around a LTO gcc problem: when there is no reference to a variable
- * in a module it will be moved to the end of the program. This causes
- * reordering of initcalls which the kernel does not like.
- * Add a dummy reference function to avoid this. The function is
- * deleted by the linker.
- */
-#define LTO_REFERENCE_INITCALL(x) \
-	; /* yes this is needed */			\
-	static __used __exit void *reference_##x(void)	\
-	{						\
-		return &x;				\
-	}
-#else
-#define LTO_REFERENCE_INITCALL(x)
-#endif
-
 /* initcalls are now grouped by functionality into separate 
  * subsections. Ordering inside the subsections is determined
  * by link order. 
@@ -180,8 +163,7 @@  extern bool initcall_debug;
 
 #define __define_initcall(fn, id) \
 	static initcall_t __initcall_##fn##id __used \
-	__attribute__((__section__(".initcall" #id ".init"))) = fn; \
-	LTO_REFERENCE_INITCALL(__initcall_##fn##id)
+	__attribute__((__section__(".initcall" #id ".init"))) = fn;
 
 /*
  * Early initcalls run before initializing SMP.