tree: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/ghostbusters head: 9a313c5d65a5f10ddf605022e9220e52946326f0 commit: 13d4ca202f2cde01512b290eeaeee35938a7b351 [9/19] arm64: Rewrite Spectre-v2 mitigation code config: arm64-randconfig-r005-20200920 (attached as .config) compiler: aarch64-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 13d4ca202f2cde01512b290eeaeee35938a7b351 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): arch/arm64/kernel/proton-pack.c: In function 'spectre_v2_enable_fw_mitigation': 287 | install_bp_hardening_cb(cb); | ^~~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors # https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?i... git remote add arm64 https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git git fetch --no-tags arm64 for-next/ghostbusters git checkout 13d4ca202f2cde01512b290eeaeee35938a7b351 vim +/install_bp_hardening_cb +287 arch/arm64/kernel/proton-pack.c 261 262 static enum mitigation_state spectre_v2_enable_fw_mitigation(void) 263 { 264 bp_hardening_cb_t cb; 265 enum mitigation_state state; 266 267 state = spectre_v2_get_cpu_fw_mitigation_state(); 268 if (state != SPECTRE_MITIGATED) 269 return state; 270 271 if (spectre_v2_mitigations_off()) 272 return SPECTRE_VULNERABLE; 273 274 switch (arm_smccc_1_1_get_conduit()) { 275 case SMCCC_CONDUIT_HVC: 276 cb = call_hvc_arch_workaround_1; 277 break; 278 279 case SMCCC_CONDUIT_SMC: 280 cb = call_smc_arch_workaround_1; 281 break; 282 283 default: 284 return SPECTRE_VULNERABLE; 285 } 286 288 return SPECTRE_MITIGATED; 289 } 290 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org