[tip:core/urgent] objtool: Enclose contents of unreachable() macro in a block

From: tip-bot for Josh Poimboeuf
Date: Tue Feb 28 2017 - 05:45:08 EST


Commit-ID: 4e4636cf981b5b629fbfb78aa9f232e015f7d521
Gitweb: http://git.kernel.org/tip/4e4636cf981b5b629fbfb78aa9f232e015f7d521
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Mon, 27 Feb 2017 22:21:16 -0600
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 28 Feb 2017 07:47:26 +0100

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 <linux@xxxxxxxxxxxx>
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")
Link: 20170228042116.glmwmwiohcix7o4a@treble">http://lkml.kernel.org/r/20170228042116.glmwmwiohcix7o4a@treble
Signed-off-by: Ingo Molnar <mingo@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..f457b52 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")))