Hi Andy, kernel test robot noticed the following build warnings: https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/driver-core-Ignore-0-in-dev_err_probe/20240826-113856 base: driver-core/driver-core-testing patch link: https://lore.kernel.org/r/20240822130722.1261891-3-andriy.shevchenko%40linux.intel.com patch subject: [PATCH v2 2/4] platform/x86: int3472: Simplify dev_err_probe() usage config: i386-randconfig-141-20240830 (https://download.01.org/0day-ci/archive/20240831/202408310807.sNPe5Mr2-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202408310807.sNPe5Mr2-lkp@xxxxxxxxx/ smatch warnings: drivers/platform/x86/intel/int3472/discrete.c:292 skl_int3472_handle_gpio_resources() error: uninitialized symbol 'err_msg'. drivers/platform/x86/intel/int3472/discrete.c:292 skl_int3472_handle_gpio_resources() warn: passing zero to 'dev_err_probe' vim +/err_msg +292 drivers/platform/x86/intel/int3472/discrete.c 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 270 case INT3472_GPIO_TYPE_POWER_ENABLE: 53c5f7f6e7930f drivers/platform/x86/intel/int3472/discrete.c Hans de Goede 2023-10-04 271 ret = skl_int3472_register_regulator(int3472, gpio); 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 272 if (ret) 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 273 err_msg = "Failed to map regulator to sensor\n"; 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 274 53c5f7f6e7930f drivers/platform/x86/intel/int3472/discrete.c Hans de Goede 2023-10-04 275 break; 53c5f7f6e7930f drivers/platform/x86/intel/int3472/discrete.c Hans de Goede 2023-10-04 276 default: /* Never reached */ 53c5f7f6e7930f drivers/platform/x86/intel/int3472/discrete.c Hans de Goede 2023-10-04 277 ret = -EINVAL; 53c5f7f6e7930f drivers/platform/x86/intel/int3472/discrete.c Hans de Goede 2023-10-04 278 break; 53c5f7f6e7930f drivers/platform/x86/intel/int3472/discrete.c Hans de Goede 2023-10-04 279 } 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 280 break; 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 281 default: 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 282 dev_warn(int3472->dev, 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 283 "GPIO type 0x%02x unknown; the sensor may not work\n", 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 284 type); 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 285 ret = 1; ^^^^^^^^ 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 286 break; 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 287 } 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 288 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 289 int3472->ngpios++; 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 290 ACPI_FREE(obj); 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 291 5de691bffe57fd drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c Daniel Scally 2021-06-03 @292 return dev_err_probe(int3472->dev, ret, err_msg); This is the success path. "err_msg" is only set for the error path. "ret" is 1 so it will use the uninitialized data. But even if ret were zero, it's illegal to pass uninitialized variables to functions which aren't inlined. 1) It's undefined behavior 2) Linus said so 3) It causes UBSan warnings at runtime. regards, dan carpenter -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
