sh: mark end of BUG() implementation as unreachable

When building the sh architecture, the compiler doesn't realize that
BUG() doesn't return, so it will complain about functions using BUG()
that are marked with the noreturn attribute:

   lib/string.c: In function 'fortify_panic':
>> lib/string.c:986:1: warning: 'noreturn' function does return
    }
    ^

Link: http://lkml.kernel.org/r/20170627192050.GA66784@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/sh/include/asm/bug.h b/arch/sh/include/asm/bug.h
index 1b77f068be2b1d027ae460ce0e6919a84223a1f1..c9828f785ca0bce1f3e49a73def335bfc67eafc7 100644 (file)
--- a/arch/sh/include/asm/bug.h
+++ b/arch/sh/include/asm/bug.h
@@ -48,6 +48,7 @@ do {                                                  \
                   "i" (__FILE__),                      \
                   "i" (__LINE__), "i" (0),             \
                   "i" (sizeof(struct bug_entry)));     \
+       unreachable();                                  \
 } while (0)
 
 #define __WARN_FLAGS(flags)                            \