tree: https://github.com/amir73il/linux fan_rename head: d853df988fac35734c681deca299d26358f3e2fd commit: 5fe3b310a5dc68cff5bd3dfbdfcc4c699a11ab15 [6/8] fanotify: record either old name new name or both for FAN_RENAME config: hexagon-randconfig-r045-20211118 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c46becf500df2a7fb4b4fce16178a036c344315a) 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/amir73il/linux/commit/5fe3b310a5dc68cff5bd3dfbdfcc4c69... git remote add amir73il https://github.com/amir73il/linux git fetch --no-tags amir73il fan_rename git checkout 5fe3b310a5dc68cff5bd3dfbdfcc4c699a11ab15 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=hexagon If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): if (WARN_ON_ONCE(!(mask & FAN_MOVE))) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/asm-generic/bug.h:179:33: note: expanded from macro 'WARN_ON_ONCE' #define WARN_ON_ONCE(condition) WARN_ON(condition) ^~~~~~~~~~~~~~~~~~ include/asm-generic/bug.h:165:28: note: expanded from macro 'WARN_ON' #define WARN_ON(condition) ({ \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/notify/fanotify/fanotify.c:856:19: note: uninitialized use occurs here set_active_memcg(old_memcg); ^~~~~~~~~ fs/notify/fanotify/fanotify.c:796:4: note: remove the 'if' if its condition is always false if (WARN_ON_ONCE(!(mask & FAN_MOVE))) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/notify/fanotify/fanotify.c:749:30: note: initialize the variable 'old_memcg' to silence this warning struct mem_cgroup *old_memcg; ^ = NULL 1 warning generated. vim +796 fs/notify/fanotify/fanotify.c 735 736 static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, 737 u32 mask, const void *data, 738 int data_type, struct inode *dir, 739 const struct qstr *file_name, 740 __kernel_fsid_t *fsid) 741 { 742 struct fanotify_event *event = NULL; 743 gfp_t gfp = GFP_KERNEL_ACCOUNT; 744 unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS); 745 struct inode *id = fanotify_fid_inode(mask, data, data_type, dir, 746 fid_mode); 747 struct inode *dirid = fanotify_dfid_inode(mask, data, data_type, dir); 748 const struct path *path = fsnotify_data_path(data, data_type); 749 struct mem_cgroup *old_memcg; 750 struct dentry *moved = NULL; 751 struct inode *child = NULL; 752 bool name_event = false; 753 unsigned int hash = 0; 754 bool ondir = mask & FAN_ONDIR; 755 struct pid *pid; 756 757 if ((fid_mode & FAN_REPORT_DIR_FID) && dirid) { 758 /* 759 * For certain events and group flags, report the child fid 760 * in addition to reporting the parent fid and maybe child name. 761 */ 762 if (fanotify_report_child_fid(fid_mode, mask) && id != dirid) 763 child = id; 764 765 id = dirid; 766 767 /* 768 * We record file name only in a group with FAN_REPORT_NAME 769 * and when we have a directory inode to report. 770 * 771 * For directory entry modification event, we record the fid of 772 * the directory and the name of the modified entry. 773 * 774 * For event on non-directory that is reported to parent, we 775 * record the fid of the parent and the name of the child. 776 * 777 * Even if not reporting name, we need a variable length 778 * fanotify_name_event if reporting both parent and child fids. 779 */ 780 if (!(fid_mode & FAN_REPORT_NAME)) { 781 name_event = !!child; 782 file_name = NULL; 783 } else if ((mask & ALL_FSNOTIFY_DIRENT_EVENTS) || !ondir) { 784 name_event = true; 785 } 786 787 /* 788 * In the special case of FAN_RENAME event, the FAN_MOVE flags 789 * are only used internally to indicate if we need to report 790 * only the old parent+name, only the new parent+name or both. 791 * 'dirid' and 'file_name' are the old parent+name and 792 * 'moved' has the new parent+name. 793 */ 794 if (mask & FAN_RENAME) { 795 /* Either old and/or new info must be reported */ 797 goto out; 798 799 if (!(mask & FAN_MOVED_FROM)) { 800 /* Do not report old parent+name */ 801 dirid = NULL; 802 file_name = NULL; 803 } 804 if (mask & FAN_MOVED_FROM) { 805 /* Report new parent+name */ 806 moved = fsnotify_data_dentry(data, data_type); 807 } 808 /* Clear internal flags */ 809 mask &= ~FAN_MOVE; 810 name_event = true; 811 } 812 } 813 814 /* 815 * For queues with unlimited length lost events are not expected and 816 * can possibly have security implications. Avoid losing events when 817 * memory is short. For the limited size queues, avoid OOM killer in the 818 * target monitoring memcg as it may have security repercussion. 819 */ 820 if (group->max_events == UINT_MAX) 821 gfp |= __GFP_NOFAIL; 822 else 823 gfp |= __GFP_RETRY_MAYFAIL; 824 825 /* Whoever is interested in the event, pays for the allocation. */ 826 old_memcg = set_active_memcg(group->memcg); 827 828 if (fanotify_is_perm_event(mask)) { 829 event = fanotify_alloc_perm_event(path, gfp); 830 } else if (fanotify_is_error_event(mask)) { 831 event = fanotify_alloc_error_event(group, fsid, data, 832 data_type, &hash); 833 } else if (name_event && (file_name || moved || child)) { 834 event = fanotify_alloc_name_event(dirid, fsid, file_name, child, 835 moved, &hash, gfp); 836 } else if (fid_mode) { 837 event = fanotify_alloc_fid_event(id, fsid, &hash, gfp); 838 } else { 839 event = fanotify_alloc_path_event(path, &hash, gfp); 840 } 841 842 if (!event) 843 goto out; 844 845 if (FAN_GROUP_FLAG(group, FAN_REPORT_TID)) 846 pid = get_pid(task_pid(current)); 847 else 848 pid = get_pid(task_tgid(current)); 849 850 /* Mix event info, FAN_ONDIR flag and pid into event merge key */ 851 hash ^= hash_long((unsigned long)pid | ondir, FANOTIFY_EVENT_HASH_BITS); 852 fanotify_init_event(event, hash, mask); 853 event->pid = pid; 854 855 out: 856 set_active_memcg(old_memcg); 857 return event; 858 } 859 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org