Linux 4.9.297 doesn't provide BUILD_BUG_ON anymore in linux/bug.h also identified itself with the version number 4.9.255 when decoding the LINUX_VERSION_CODE. So we have to try to guess now if we need to include linux/build_bug.h based on whether BUILD_BUG_ON is defined or not after including linux/bug.h.

If not doing this, the build will fail with errors like:

net/batman-adv/bat_algo.c:146:1: error: undefined identifier 'BUILD_BUG_ON_ZERO' net/batman-adv/bat_algo.c:146:1: error: undefined identifier 'BUILD_BUG_ON_ZERO' net/batman-adv/bat_algo.c:146:1: error: undefined identifier 'BUILD_BUG_ON_ZERO' net/batman-adv/bat_algo.c:146:1: error: undefined identifier 'BUILD_BUG_ON_ZERO' net/batman-adv/bat_algo.c:146:1: error: undefined identifier 'BUILD_BUG_ON_ZERO' net/batman-adv/bat_algo.c:146:1: error: undefined identifier 'BUILD_BUG_ON_ZERO' In file included from ./arch/x86/include/asm/cpufeatures.h:5, from ./arch/x86/include/asm/cmpxchg.h:5, from ./arch/x86/include/asm/atomic.h:7, from ./include/linux/atomic.h:4, from net/batman-adv/main.h:207, from net/batman-adv/bat_algo.c:7: ./arch/x86/include/asm/qspinlock.h: In function ‘virt_spin_lock’: ./arch/x86/include/asm/required-features.h:104:29: error: implicit declaration of function ‘BUILD_BUG_ON_ZERO’ [-Werror=implicit-function-declaration]

Signed-off-by: Sven Eckelmann sven@narfation.org --- compat-include/linux/build_bug.h | 11 +++++++++++ 1 file changed, 11 insertions(+)

diff --git a/compat-include/linux/build_bug.h b/compat-include/linux/build_bug.h index 0eecc688..1002431d 100644 --- a/compat-include/linux/build_bug.h +++ b/compat-include/linux/build_bug.h @@ -15,6 +15,17 @@ #include_next <linux/build_bug.h> #else #include <linux/bug.h> + +/* Linux 4.9.297 doesn't provide BUILD_BUG_ON anymore in linux/bug.h + * also identified itself with the version number 4.9.255 when decoding the + * LINUX_VERSION_CODE. So we have to try to guess now if we need to include + * linux/build_bug.h based on whether BUILD_BUG_ON is defined or not after + * including linux/bug.h + */ +#ifndef BUILD_BUG_ON +#include_next <linux/build_bug.h> +#endif + #endif

#endif /* _NET_BATMAN_ADV_COMPAT_LINUX_BUILD_BUG_H_ */