Hi Peter, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on arm-perf/for-next/perf] [also build test WARNING on linus/master v5.7-rc6] [cannot apply to arm64/for-next/core next-20200519] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Peter-Collingbourne/arm64-Expose... base: https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git for-next/perf config: arm64-randconfig-r005-20200520 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 3393cc4cebf9969db94dc424b7a2b6195589c33b) 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 # install arm64 cross compiling tool for clang build # apt-get install binutils-aarch64-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): WARN(1, "ESR 0x%x is not DABT or IABT from EL0n", esr); ~~ ^~~ %lx include/asm-generic/bug.h:124:29: note: expanded from macro 'WARN' __WARN_printf(TAINT_WARN, format); ^~~~~~ include/asm-generic/bug.h:92:17: note: expanded from macro '__WARN_printf' __warn_printk(arg); ^~~ arch/arm64/kernel/traps.c:826:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized", ^~~~~~~~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:827:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_WFx] = "WFI/WFE", ^~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:828:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_CP15_32] = "CP15 MCR/MRC", ^~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:829:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_CP15_64] = "CP15 MCRR/MRRC", ^~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:830:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_CP14_MR] = "CP14 MCR/MRC", ^~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:831:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_CP14_LS] = "CP14 LDC/STC", ^~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:832:27: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_FP_ASIMD] = "ASIMD", ^~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:833:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_CP10_ID] = "CP10 MRC/VMRS", ^~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:834:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_PAC] = "PAC", ^~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:835:26: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_CP14_64] = "CP14 MCRR/MRRC", ^~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:836:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_ILL] = "PSTATE.IL", ^~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:837:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_SVC32] = "SVC (AArch32)", ^~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:838:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_HVC32] = "HVC (AArch32)", ^~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:839:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_SMC32] = "SMC (AArch32)", ^~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:840:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [ESR_ELx_EC_SVC64] = "SVC (AArch64)", ^~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:825:28: note: previous initialization is here [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", ^~~~~~~~~~~~~~~~~ arch/arm64/kernel/traps.c:841:24: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] vim +283 arch/arm64/kernel/traps.c 236 237 static unsigned long esr_to_error_code(unsigned long esr, unsigned long far) 238 { 239 /* 240 * If the faulting address is in the kernel, we must sanitize the ESR. 241 * From userspace's point of view, kernel-only mappings don't exist 242 * at all, so we report them as level 0 translation faults. 243 * (This is not quite the way that "no mapping there at all" behaves: 244 * an alignment fault not caused by the memory type would take 245 * precedence over translation fault for a real access to empty 246 * space. Unfortunately we can't easily distinguish "alignment fault 247 * not caused by memory type" from "alignment fault caused by memory 248 * type", so we ignore this wrinkle and just return the translation 249 * fault.) 250 */ 251 if (!is_ttbr0_addr(untagged_addr(far))) { 252 switch (ESR_ELx_EC(esr)) { 253 case ESR_ELx_EC_DABT_LOW: 254 /* 255 * These bits provide only information about the 256 * faulting instruction, which userspace knows already. 257 * We explicitly clear bits which are architecturally 258 * RES0 in case they are given meanings in future. 259 * We always report the ESR as if the fault was taken 260 * to EL1 and so ISV and the bits in ISS[23:14] are 261 * clear. (In fact it always will be a fault to EL1.) 262 */ 263 esr &= ESR_ELx_EC_MASK | ESR_ELx_IL | 264 ESR_ELx_CM | ESR_ELx_WNR; 265 esr |= ESR_ELx_FSC_FAULT; 266 break; 267 case ESR_ELx_EC_IABT_LOW: 268 /* 269 * Claim a level 0 translation fault. 270 * All other bits are architecturally RES0 for faults 271 * reported with that DFSC value, so we clear them. 272 */ 273 esr &= ESR_ELx_EC_MASK | ESR_ELx_IL; 274 esr |= ESR_ELx_FSC_FAULT; 275 break; 276 default: 277 /* 278 * This should never happen (entry.S only brings us 279 * into this code for insn and data aborts from a lower 280 * exception level). Fail safe by not providing an ESR 281 * context record at all. 282 */ 284 esr = 0; 285 break; 286 } 287 } 288 289 if (is_compat_task()) { 290 /* Use the compat FSR WnR */ 291 return !!(esr & ESR_ELx_WNR) << FSR_WRITE_SHIFT; 292 } 293 294 return esr; 295 } 296 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org