objtool: Enclose contents of unreachable() macro in a block

Guenter Roeck reported a boot failure in mips64.  It was bisected to the
following commit:

  d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")

The unreachable() macro was formerly only composed of a single
statement.  The above commit added a second statement, but neglected to
enclose the statements in a block.

Suggested-by: Guenter Roeck <[email protected]>
Reported-by: Guenter Roeck <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")
Link: http://lkml.kernel.org/r/20170228042116.glmwmwiohcix7o4a@treble
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index de471346b365f82809f109b3c90288213771f759..f457b520ead6e81d4cde702bf0eb13d74eb7907d 100644 (file)
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -215,7 +215,8 @@
  * 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() annotate_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")))