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

[Adrian Hunter]

On 10/04/24 13:56, Naresh Kamboju wrote:
> The powerpc,s390, superSh and sparc tinyconfig builds failed due to
> following build
> warnings / errors on the Linux next-20240410 with gcc-13 and gcc-11.
> 
> List build failures:
> ---
> * s390, build
>   - gcc-13-tinyconfig - failed
>   - gcc-8-tinyconfig - failed
> 
> * sh, build
>   - gcc-11-tinyconfig - failed
> 
> * sparc, build
>   - gcc-11-tinyconfig - failed
> 
> * mips, build
>   - gcc-12-tinyconfig - failed
>   - gcc-8-tinyconfig - failed
> 
> * powerpc, build
>   - gcc-13-tinyconfig - failed
>   - gcc-8-tinyconfig - failed
> 
> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> 
> Build log:
> --------
> 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]
>   286 | }
>       | ^
> cc1: some warnings being treated as errors

Using unreachable() in the default BUG() seems to make this go
away.

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 6e794420bd39..891bd9b0be70 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -156,7 +156,7 @@ 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


> 
> steps to reproduce:
> ---
> # tuxmake --runtime podman --target-arch powerpc --toolchain gcc-13
> --kconfig tinyconfig
> 
> Links:
>  - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240410/testrun/23380322/suite/build/test/gcc-13-tinyconfig/details/
>  - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240410/testrun/23380301/suite/build/test/gcc-11-tinyconfig/history/
>  - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240410/testrun/23380301/suite/build/tests/
> 
> --
> Linaro LKFT
> https://lkft.linaro.org