tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 33b64befb1a28bca3f5a9ed9807d2f87e976c63a commit: af66b51563ad7e625602809a0f4c45154df063d1 [8396/9381] file: convert to SLAB_TYPESAFE_BY_RCU config: i386-randconfig-061-20231004 (https://download.01.org/0day-ci/archive/20231004/202310041744.d34gIv9V-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231004/202310041744.d34gIv9V-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/202310041744.d34gIv9V-lkp@xxxxxxxxx/ sparse warnings: (new ones prefixed by >>) fs/file.c:379:17: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct file **old_fds @@ got struct file [noderef] __rcu **fd @@ fs/file.c:379:17: sparse: expected struct file **old_fds fs/file.c:379:17: sparse: got struct file [noderef] __rcu **fd fs/file.c:380:17: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct file **new_fds @@ got struct file [noderef] __rcu **fd @@ fs/file.c:380:17: sparse: expected struct file **new_fds fs/file.c:380:17: sparse: got struct file [noderef] __rcu **fd fs/file.c:395:17: sparse: sparse: incompatible types in comparison expression (different address spaces): fs/file.c:395:17: sparse: struct file [noderef] __rcu * fs/file.c:395:17: sparse: struct file * fs/file.c:430:54: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct file *file @@ got struct file [noderef] __rcu *[assigned] __ret @@ fs/file.c:470:28: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct fdtable [noderef] __rcu *fdt @@ got struct fdtable * @@ fs/file.c:646:14: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct file *file @@ got struct file [noderef] __rcu * @@ fs/file.c:841:30: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct file *file @@ got struct file [noderef] __rcu * @@ >> fs/file.c:875:22: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct file [noderef] __rcu *file @@ got struct file * @@ >> fs/file.c:879:21: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct atomic_t [usertype] *v @@ got struct atomic_t [noderef] __rcu * @@ >> fs/file.c:882:31: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct file [noderef] __rcu *file_reloaded @@ got struct file * @@ >> fs/file.c:906:32: sparse: sparse: incorrect type in return expression (different address spaces) @@ expected struct file * @@ got struct file [noderef] __rcu *file_reloaded @@ >> fs/file.c:908:22: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct file * @@ got struct file [noderef] __rcu *file @@ fs/file.c:1200:16: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct file *tofree @@ got struct file [noderef] __rcu * @@ vim +875 fs/file.c 855 856 /** 857 * get_file_rcu - try go get a reference to a file under rcu 858 * @f: the file to get a reference on 859 * 860 * This function tries to get a reference on @f carefully verifying that 861 * @f hasn't been reused. 862 * 863 * This function should rarely have to be used and only by users who 864 * understand the implications of SLAB_TYPESAFE_BY_RCU. Try to avoid it. 865 * 866 * Return: Returns @f with the reference count increased or NULL. 867 */ 868 struct file *get_file_rcu(struct file __rcu **f) 869 { 870 for (;;) { 871 struct file __rcu *file; 872 struct file __rcu *file_reloaded; 873 struct file __rcu *file_reloaded_cmp; 874 > 875 file = rcu_dereference_raw(*f); 876 if (!file) 877 return NULL; 878 > 879 if (unlikely(!atomic_long_inc_not_zero(&file->f_count))) 880 continue; 881 > 882 file_reloaded = rcu_dereference_raw(*f); 883 884 /* 885 * Ensure that all accesses have a dependency on the 886 * load from rcu_dereference_raw() above so we get 887 * correct ordering between reuse/allocation and the 888 * pointer check below. 889 */ 890 file_reloaded_cmp = file_reloaded; 891 OPTIMIZER_HIDE_VAR(file_reloaded_cmp); 892 893 /* 894 * atomic_long_inc_not_zero() above provided a full 895 * memory barrier when we acquired a reference. 896 * 897 * This is paired with the write barrier from assigning 898 * to the __rcu protected file pointer so that if that 899 * pointer still matches the current file, we know we 900 * have successfully acquire a reference to it. 901 * 902 * If the pointers don't match the file has been 903 * reallocated by SLAB_TYPESAFE_BY_RCU. 904 */ 905 if (file == file_reloaded_cmp) > 906 return file_reloaded; 907 > 908 fput(file); 909 } 910 } 911 EXPORT_SYMBOL_GPL(get_file_rcu); 912 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
