[PATCH] bug: Fix no-return-statement warning with !CONFIG_BUG

Adrian Hunter
2024-04-10T15:32:32Z

BUG() does not return, and arch implementations of BUG() use unreachable()
or other non-returning code. However with !CONFIG_BUG, the default
implementation is often used instead, and that does not do that. x86 always
uses its own implementation, but powerpc with !CONFIG_BUG gives a build
error:

kernel/time/timekeeping.c: In function ‘timekeeping_debug_get_ns’:
kernel/time/timekeeping.c:286:1: error: no return statement in function
returning non-void [-Werror=return-type]

Add unreachable() to default !CONFIG_BUG BUG() implementation.

Fixes: e8e9d21a5df6 ("timekeeping: Refactor timekeeping helpers")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Closes: https://lore.kernel.org/all/CA+G9fYvjdZCW=7ZGxS6A_3bysjQ56YF7S-+PNLQ_8a4DKh1Bhg@mail.gmail.com/
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
include/asm-generic/bug.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 6e794420bd39..b7de3a4eade1 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -156,7 +156,10 @@ extern __printf(1, 2) void __warn_printk(const char *fmt, ...);

#else /* !CONFIG_BUG */
#ifndef HAVE_ARCH_BUG
-#define BUG() do {} while (1)
+#define BUG() do { \
+ do {} while (1); \
+ unreachable(); \
+} while (0)
#endif

#ifndef HAVE_ARCH_BUG_ON
--
2.34.1