Hi Dave, kernel test robot noticed the following build warnings: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Dave-Marchevsky/bpf-Don-t-explicitly-emit-BTF-for-struct-btf_iter_num/20231003-035600 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20231002195341.2940874-3-davemarchevsky%40fb.com patch subject: [PATCH v4 bpf-next 2/3] bpf: Introduce task_vma open-coded iterator kfuncs config: i386-buildonly-randconfig-001-20231003 (https://download.01.org/0day-ci/archive/20231004/202310040045.CufS8H4U-lkp@xxxxxxxxx/config) compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231004/202310040045.CufS8H4U-lkp@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202310040045.CufS8H4U-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> kernel/bpf/task_iter.c:827:17: warning: no previous declaration for 'bpf_iter_task_vma_new' [-Wmissing-declarations] __bpf_kfunc int bpf_iter_task_vma_new(struct bpf_iter_task_vma *it, ^~~~~~~~~~~~~~~~~~~~~ >> kernel/bpf/task_iter.c:871:36: warning: no previous declaration for 'bpf_iter_task_vma_next' [-Wmissing-declarations] __bpf_kfunc struct vm_area_struct *bpf_iter_task_vma_next(struct bpf_iter_task_vma *it) ^~~~~~~~~~~~~~~~~~~~~~ >> kernel/bpf/task_iter.c:880:18: warning: no previous declaration for 'bpf_iter_task_vma_destroy' [-Wmissing-declarations] __bpf_kfunc void bpf_iter_task_vma_destroy(struct bpf_iter_task_vma *it) ^~~~~~~~~~~~~~~~~~~~~~~~~ vim +/bpf_iter_task_vma_new +827 kernel/bpf/task_iter.c 826 > 827 __bpf_kfunc int bpf_iter_task_vma_new(struct bpf_iter_task_vma *it, 828 struct task_struct *task, u64 addr) 829 { 830 struct bpf_iter_task_vma_kern *kit = (void *)it; 831 bool irq_work_busy = false; 832 int err; 833 834 BUILD_BUG_ON(sizeof(struct bpf_iter_task_vma_kern) != sizeof(struct bpf_iter_task_vma)); 835 BUILD_BUG_ON(__alignof__(struct bpf_iter_task_vma_kern) != __alignof__(struct bpf_iter_task_vma)); 836 837 /* is_iter_reg_valid_uninit guarantees that kit hasn't been initialized 838 * before, so non-NULL kit->data doesn't point to previously 839 * bpf_mem_alloc'd bpf_iter_task_vma_kern_data 840 */ 841 kit->data = bpf_mem_alloc(&bpf_global_ma, sizeof(struct bpf_iter_task_vma_kern_data)); 842 if (!kit->data) 843 return -ENOMEM; 844 845 kit->data->task = get_task_struct(task); 846 kit->data->mm = task->mm; 847 if (!kit->data->mm) { 848 err = -ENOENT; 849 goto err_cleanup_iter; 850 } 851 852 /* kit->data->work == NULL is valid after bpf_mmap_unlock_get_irq_work */ 853 irq_work_busy = bpf_mmap_unlock_get_irq_work(&kit->data->work); 854 if (irq_work_busy || !mmap_read_trylock(kit->data->mm)) { 855 err = -EBUSY; 856 goto err_cleanup_iter; 857 } 858 859 vma_iter_init(&kit->data->vmi, kit->data->mm, addr); 860 return 0; 861 862 err_cleanup_iter: 863 if (kit->data->task) 864 put_task_struct(kit->data->task); 865 bpf_mem_free(&bpf_global_ma, kit->data); 866 /* NULL kit->data signals failed bpf_iter_task_vma initialization */ 867 kit->data = NULL; 868 return err; 869 } 870 > 871 __bpf_kfunc struct vm_area_struct *bpf_iter_task_vma_next(struct bpf_iter_task_vma *it) 872 { 873 struct bpf_iter_task_vma_kern *kit = (void *)it; 874 875 if (!kit->data) /* bpf_iter_task_vma_new failed */ 876 return NULL; 877 return vma_next(&kit->data->vmi); 878 } 879 > 880 __bpf_kfunc void bpf_iter_task_vma_destroy(struct bpf_iter_task_vma *it) 881 { 882 struct bpf_iter_task_vma_kern *kit = (void *)it; 883 884 if (kit->data) { 885 bpf_mmap_unlock_mm(kit->data->work, kit->data->mm); 886 put_task_struct(kit->data->task); 887 bpf_mem_free(&bpf_global_ma, kit->data); 888 } 889 } 890 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
