Re: [PATCH] printk: add early_counter_ns routine for printk blind spot

kernel test robot
2025-11-27T09:13:43Z

Hi Tim,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.18-rc7]
[cannot apply to akpm-mm/mm-everything next-20251127]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Tim-Bird/printk-add-early_counter_ns-routine-for-printk-blind-spot/20251125-133242
base: linus/master
patch link: https://lore.kernel.org/r/39b09edb-8998-4ebd-a564-7d594434a981%40bird.org
patch subject: [PATCH] printk: add early_counter_ns routine for printk blind spot
config: i386-randconfig-2006-20250825 (https://download.01.org/0day-ci/archive/20251127/202511271051.yfp2O98B-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251127/202511271051.yfp2O98B-lkp@intel.com/reproduce)

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/202511271051.yfp2O98B-lkp@intel.com/

All errors (new ones prefixed by >>):

ld: init/main.o: in function `kernel_init':
>> init/main.c:1522:(.ref.text+0x201): undefined reference to `__udivdi3'

vim +1522 init/main.c

1481
1482 static int __ref kernel_init(void *unused)
1483 {
1484 int ret;
1485 u64 end_cycles, end_ns;
1486 u32 early_mult, early_shift;
1487
1488 /*
1489 * Wait until kthreadd is all set-up.
1490 */
1491 wait_for_completion(&kthreadd_done);
1492
1493 kernel_init_freeable();
1494 /* need to finish all async __init code before freeing the memory */
1495 async_synchronize_full();
1496
1497 system_state = SYSTEM_FREEING_INITMEM;
1498 kprobe_free_init_mem();
1499 ftrace_free_init_mem();
1500 kgdb_free_init_mem();
1501 exit_boot_config();
1502 free_initmem();
1503 mark_readonly();
1504
1505 /*
1506 * Kernel mappings are now finalized - update the userspace page-table
1507 * to finalize PTI.
1508 */
1509 pti_finalize();
1510
1511 system_state = SYSTEM_RUNNING;
1512 numa_default_policy();
1513
1514 rcu_end_inkernel_boot();
1515
1516 do_sysctl_args();
1517
1518 /* show calibration data for early_counter_ns */
1519 end_cycles = get_cycles();
1520 end_ns = local_clock();
1521 clocks_calc_mult_shift(&early_mult, &early_shift,
> 1522 ((end_cycles - start_cycles) * NSEC_PER_SEC)/(end_ns - start_ns),
1523 NSEC_PER_SEC, 50);
1524

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0-DAY CI Kernel Test Service