[PATCH] objtool: enclose contents of unreachable() macro in a block

From: Josh Poimboeuf
Date: Mon Feb 27 2017 - 23:23:11 EST



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.

Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Suggested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
include/linux/compiler-gcc.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index de47134..f457b520 100644
--- 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")))
--
2.7.4