Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fixes from Ingo Molnar:
 "A handful of objtool fixes related to unreachable code, plus a build
  fix for out of tree modules"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Enclose contents of unreachable() macro in a block
  objtool: Prevent GCC from merging annotate_unreachable()
  objtool: Improve detection of BUG() and other dead ends
  objtool: Fix CONFIG_STACK_VALIDATION=y warning for out-of-tree modules

1 files changed, 13 insertions, 1 deletions

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 811f7a915658..76e28c229805 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -197,6 +197,17 @@
 #endif
 #endif
 
+#ifdef CONFIG_STACK_VALIDATION
+#define annotate_unreachable() ({                                       \
+        asm("%c0:\t\n"                                                  \
+            ".pushsection __unreachable, \"a\"\t\n"                     \
+            ".long %c0b\t\n"                                            \
+            ".popsection\t\n" : : "i" (__LINE__));                      \
+})
+#else
+#define annotate_unreachable()
+#endif
+
 /*
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer
@@ -206,7 +217,8 @@
  * this in the preprocessor, but we can live with this because they're
  * unreleased.  Really, we need to have autoconf for the kernel.
  */
-#define unreachable() __builtin_unreachable()
+#define unreachable() \
+        do { annotate_unreachable(); __builtin_unreachable(); } while (0)
 
 /* Mark a function definition as prohibited from being cloned. */
 #define __noclone       __attribute__((__noclone__, __optimize__("no-tracer")))