Hi Nathan, I love your patch! Perhaps something to improve: [auto build test WARNING on 7c53f6b671f4aba70ff15e1b05148b10d58c2837] url: https://github.com/0day-ci/linux/commits/Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714 base: 7c53f6b671f4aba70ff15e1b05148b10d58c2837 config: m68k-allmodconfig (attached as .config) compiler: m68k-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 # https://github.com/0day-ci/linux/commit/775adad26a60878926c0ee6cd460a1375bbe51e6 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714 git checkout 775adad26a60878926c0ee6cd460a1375bbe51e6 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): lib/ubsan.c:192:6: warning: no previous prototype for '__ubsan_handle_add_overflow' [-Wmissing-prototypes] 192 | void __ubsan_handle_add_overflow(void *data, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:200:6: warning: no previous prototype for '__ubsan_handle_sub_overflow' [-Wmissing-prototypes] 200 | void __ubsan_handle_sub_overflow(void *data, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:207:6: warning: no previous prototype for '__ubsan_handle_mul_overflow' [-Wmissing-prototypes] 207 | void __ubsan_handle_mul_overflow(void *data, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:214:6: warning: no previous prototype for '__ubsan_handle_negate_overflow' [-Wmissing-prototypes] 214 | void __ubsan_handle_negate_overflow(void *_data, void *old_val) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:234:6: warning: no previous prototype for '__ubsan_handle_divrem_overflow' [-Wmissing-prototypes] 234 | void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:315:6: warning: no previous prototype for '__ubsan_handle_type_mismatch' [-Wmissing-prototypes] 315 | void __ubsan_handle_type_mismatch(struct type_mismatch_data *data, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:329:6: warning: no previous prototype for '__ubsan_handle_type_mismatch_v1' [-Wmissing-prototypes] 329 | void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:343:6: warning: no previous prototype for '__ubsan_handle_out_of_bounds' [-Wmissing-prototypes] 343 | void __ubsan_handle_out_of_bounds(void *_data, void *index) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:360:6: warning: no previous prototype for '__ubsan_handle_shift_out_of_bounds' [-Wmissing-prototypes] 360 | void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:402:6: warning: no previous prototype for '__ubsan_handle_builtin_unreachable' [-Wmissing-prototypes] 402 | void __ubsan_handle_builtin_unreachable(void *_data) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/ubsan.c:412:6: warning: no previous prototype for '__ubsan_handle_load_invalid_value' [-Wmissing-prototypes] 412 | void __ubsan_handle_load_invalid_value(void *_data, void *val) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> lib/ubsan.c:431:6: warning: no previous prototype for '__ubsan_handle_alignment_assumption' [-Wmissing-prototypes] 431 | void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/__ubsan_handle_alignment_assumption +431 lib/ubsan.c 359 > 360 void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs) 361 { 362 struct shift_out_of_bounds_data *data = _data; 363 struct type_descriptor *rhs_type = data->rhs_type; 364 struct type_descriptor *lhs_type = data->lhs_type; 365 char rhs_str[VALUE_LENGTH]; 366 char lhs_str[VALUE_LENGTH]; 367 unsigned long ua_flags = user_access_save(); 368 369 if (suppress_report(&data->location)) 370 goto out; 371 372 ubsan_prologue(&data->location, "shift-out-of-bounds"); 373 374 val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs); 375 val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs); 376 377 if (val_is_negative(rhs_type, rhs)) 378 pr_err("shift exponent %s is negative\n", rhs_str); 379 380 else if (get_unsigned_val(rhs_type, rhs) >= 381 type_bit_width(lhs_type)) 382 pr_err("shift exponent %s is too large for %u-bit type %s\n", 383 rhs_str, 384 type_bit_width(lhs_type), 385 lhs_type->type_name); 386 else if (val_is_negative(lhs_type, lhs)) 387 pr_err("left shift of negative value %s\n", 388 lhs_str); 389 else 390 pr_err("left shift of %s by %s places cannot be" 391 " represented in type %s\n", 392 lhs_str, rhs_str, 393 lhs_type->type_name); 394 395 ubsan_epilogue(); 396 out: 397 user_access_restore(ua_flags); 398 } 399 EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds); 400 401 402 void __ubsan_handle_builtin_unreachable(void *_data) 403 { 404 struct unreachable_data *data = _data; 405 ubsan_prologue(&data->location, "unreachable"); 406 pr_err("calling __builtin_unreachable()\n"); 407 ubsan_epilogue(); 408 panic("can't return from __builtin_unreachable()"); 409 } 410 EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable); 411 412 void __ubsan_handle_load_invalid_value(void *_data, void *val) 413 { 414 struct invalid_value_data *data = _data; 415 char val_str[VALUE_LENGTH]; 416 417 if (suppress_report(&data->location)) 418 return; 419 420 ubsan_prologue(&data->location, "invalid-load"); 421 422 val_to_string(val_str, sizeof(val_str), data->type, val); 423 424 pr_err("load of value %s is not a valid value for type %s\n", 425 val_str, data->type->type_name); 426 427 ubsan_epilogue(); 428 } 429 EXPORT_SYMBOL(__ubsan_handle_load_invalid_value); 430 > 431 void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr, --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org