1 files changed, 33 insertions, 41 deletions

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 469a64dd6495..efd43df3a99a 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -109,44 +109,21 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 
 /* Unreachable code */
 #ifdef CONFIG_OBJTOOL
-/*
- * These macros help objtool understand GCC code flow for unreachable code.
- * The __COUNTER__ based labels are a hack to make each instance of the macros
- * unique, to convince GCC not to merge duplicate inline asm statements.
- */
-#define __stringify_label(n) #n
-
-#define __annotate_reachable(c) ({					\
-	asm volatile(__stringify_label(c) ":\n\t"			\
-			".pushsection .discard.reachable\n\t"		\
-			".long " __stringify_label(c) "b - .\n\t"	\
-			".popsection\n\t");				\
-})
-#define annotate_reachable() __annotate_reachable(__COUNTER__)
-
-#define __annotate_unreachable(c) ({					\
-	asm volatile(__stringify_label(c) ":\n\t"			\
-		     ".pushsection .discard.unreachable\n\t"		\
-		     ".long " __stringify_label(c) "b - .\n\t"		\
-		     ".popsection\n\t" : : "i" (c));			\
-})
-#define annotate_unreachable() __annotate_unreachable(__COUNTER__)
-
 /* Annotate a C jump table to allow objtool to follow the code flow */
 #define __annotate_jump_table __section(".rodata..c_jump_table,\"a\",@progbits #")
-
 #else /* !CONFIG_OBJTOOL */
-#define annotate_reachable()
-#define annotate_unreachable()
 #define __annotate_jump_table
 #endif /* CONFIG_OBJTOOL */
 
-#ifndef unreachable
-# define unreachable() do {		\
-	annotate_unreachable();		\
+/*
+ * Mark a position in code as unreachable.  This can be used to
+ * suppress control flow warnings after asm blocks that transfer
+ * control elsewhere.
+ */
+#define unreachable() do {		\
+	barrier_before_unreachable();	\
 	__builtin_unreachable();	\
 } while (0)
-#endif
 
 /*
  * KENTRY - kernel entry point
@@ -216,28 +193,43 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 
 #endif /* __KERNEL__ */
 
+/**
+ * offset_to_ptr - convert a relative memory offset to an absolute pointer
+ * @off:	the address of the 32-bit offset value
+ */
+static inline void *offset_to_ptr(const int *off)
+{
+	return (void *)((unsigned long)off + *off);
+}
+
+#endif /* __ASSEMBLY__ */
+
+#ifdef CONFIG_64BIT
+#define ARCH_SEL(a,b) a
+#else
+#define ARCH_SEL(a,b) b
+#endif
+
 /*
  * Force the compiler to emit 'sym' as a symbol, so that we can reference
  * it from inline assembler. Necessary in case 'sym' could be inlined
  * otherwise, or eliminated entirely due to lack of references that are
  * visible to the compiler.
  */
-#define ___ADDRESSABLE(sym, __attrs) \
-	static void * __used __attrs \
+#define ___ADDRESSABLE(sym, __attrs)						\
+	static void * __used __attrs						\
 	__UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)(uintptr_t)&sym;
+
 #define __ADDRESSABLE(sym) \
 	___ADDRESSABLE(sym, __section(".discard.addressable"))
 
-/**
- * offset_to_ptr - convert a relative memory offset to an absolute pointer
- * @off:	the address of the 32-bit offset value
- */
-static inline void *offset_to_ptr(const int *off)
-{
-	return (void *)((unsigned long)off + *off);
-}
+#define __ADDRESSABLE_ASM(sym)						\
+	.pushsection .discard.addressable,"aw";				\
+	.align ARCH_SEL(8,4);						\
+	ARCH_SEL(.quad, .long) __stringify(sym);			\
+	.popsection;
 
-#endif /* __ASSEMBLY__ */
+#define __ADDRESSABLE_ASM_STR(sym) __stringify(__ADDRESSABLE_ASM(sym))
 
 #ifdef __CHECKER__
 #define __BUILD_BUG_ON_ZERO_MSG(e, msg) (0)