https://gcc.gnu.org/bugzilla/show_bug.cgi?id=28901
--- Comment #37 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Note this change also introduces some warnings when compiling the arm64 kernel: In file included from arch/arm64/crypto/aes-glue.c:17:0: include/linux/cpufeature.h:48:33: warning: ‘cpu_feature_match_AES’ defined but not used [-Wunused-const-variable=] static struct cpu_feature const cpu_feature_match_ ## x[] = \ ^ arch/arm64/crypto/aes-glue.c:452:1: note: in expansion of macro ‘module_cpu_feature_match’ module_cpu_feature_match(AES, aes_init); ^~~~~~~~~~~~~~~~~~~~~~~~ MODULE_DEVICE_TABLE(cpu, cpu_feature_match_ ## x); \ This happens when the aes crypto code is compiled in rather than a module.