Hi Li, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git OLK-5.10 head: 1588d318a9e388d05b6cf5e2a63134c8beb6a355 commit: f86d165bfe5f6248743774bb07af0bd7cff12443 [3415/3415] arm64: Add non nmi ipi backtrace support config: arm64-allnoconfig (https://download.01.org/0day-ci/archive/20251222/202512220254.DKUPaC7y-lkp@i...) compiler: aarch64-linux-gcc (GCC) 15.1.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251222/202512220254.DKUPaC7y-lkp@i...) 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@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202512220254.DKUPaC7y-lkp@intel.com/ All errors (new ones prefixed by >>): arch/arm64/kernel/ipi_nmi.c: In function 'ipi_cpu_backtrace': arch/arm64/kernel/ipi_nmi.c:38:9: error: implicit declaration of function 'printk_safe_enter'; did you mean 'printk_nmi_enter'? [-Werror=implicit-function-declaration] 38 | printk_safe_enter(); | ^~~~~~~~~~~~~~~~~ | printk_nmi_enter

...

arch/arm64/kernel/ipi_nmi.c:40:9: error: implicit declaration of function 'printk_safe_exit'; did you mean 'printk_nmi_exit'? [-Werror=implicit-function-declaration] 40 | printk_safe_exit(); | ^~~~~~~~~~~~~~~~ | printk_nmi_exit cc1: some warnings being treated as errors

vim +40 arch/arm64/kernel/ipi_nmi.c 35 36 static void ipi_cpu_backtrace(void *info) 37 {

38 printk_safe_enter(); 39 nmi_cpu_backtrace(get_irq_regs()); 40 printk_safe_exit(); 41 } 42

-- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki