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[PATCH v2] x86: remove LTO_REFERENCE_INITCALL()

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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.

Tested-by: 0-day
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 include/linux/init.h | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

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.
-- 
2.8.4

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Is LTO_REFERENCE_INITCALL() still needed? "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-06-24 01:40 +0200
  Re: Is LTO_REFERENCE_INITCALL() still needed? Andi Kleen <andi@firstfloor.org> - 2016-06-24 23:10 +0200
    Re: Is LTO_REFERENCE_INITCALL() still needed? "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-06-28 02:50 +0200
      [PATCH] x86: remove LTO flags "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-07-07 02:30 +0200
        Re: [PATCH] x86: remove LTO flags Andi Kleen <andi@firstfloor.org> - 2016-07-07 04:00 +0200
          [PATCH v2] x86: remove LTO_REFERENCE_INITCALL() "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-07-07 18:10 +0200
            Re: [PATCH v2] x86: remove LTO_REFERENCE_INITCALL() Andi Kleen <andi@firstfloor.org> - 2016-07-07 18:40 +0200

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