tree: https://github.com/osandov/linux.git btrfs-send-encoded head: d3940b20ce9f2cf1e25106a87ddd90e165e34674 commit: ced2f02da25627eccaa276c08183a2764795c93f [8/14] btrfs: add BTRFS_IOC_ENCODED_READ config: arc-randconfig-s031-20210816 (attached as .config) compiler: arceb-elf-gcc (GCC) 11.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.3-348-gf0e6938b-dirty # https://github.com/osandov/linux/commit/ced2f02da25627eccaa276c08183a2764... git remote add osandov https://github.com/osandov/linux.git git fetch --no-tags osandov btrfs-send-encoded git checkout ced2f02da25627eccaa276c08183a2764795c93f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=arc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) fs/btrfs/ioctl.c:4957:38: sparse: expected struct iovec const [noderef] __user *uvec fs/btrfs/ioctl.c:4957:38: sparse: got struct iovec const *[addressable] iov fs/btrfs/ioctl.c:408:6: sparse: sparse: context imbalance in 'btrfs_exclop_start_try_lock' - wrong count at exit fs/btrfs/ioctl.c:419:6: sparse: sparse: context imbalance in 'btrfs_exclop_start_unlock' - unexpected unlock vim +4957 fs/btrfs/ioctl.c 4906 4907 static int btrfs_ioctl_encoded_read(struct file *file, void __user *argp, 4908 bool compat) 4909 { 4910 struct btrfs_ioctl_encoded_io_args args; 4911 size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args, 4912 flags); 4913 size_t copy_end; 4914 struct iovec iovstack[UIO_FASTIOV]; 4915 struct iovec *iov = iovstack; 4916 struct iov_iter iter; 4917 loff_t pos; 4918 struct kiocb kiocb; 4919 ssize_t ret; 4920 4921 if (!capable(CAP_SYS_ADMIN)) { 4922 ret = -EPERM; 4923 goto out_acct; 4924 } 4925 4926 if (compat) { 4927 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT) 4928 struct btrfs_ioctl_encoded_io_args_32 args32; 4929 4930 copy_end = offsetofend(struct btrfs_ioctl_encoded_io_args_32, 4931 flags); 4932 if (copy_from_user(&args32, argp, copy_end)) { 4933 ret = -EFAULT; 4934 goto out_acct; 4935 } 4936 args.iov = compat_ptr(args32.iov); 4937 args.iovcnt = args32.iovcnt; 4938 args.offset = args32.offset; 4939 args.flags = args32.flags; 4940 #else 4941 return -ENOTTY; 4942 #endif 4943 } else { 4944 copy_end = copy_end_kernel; 4945 if (copy_from_user(&args, argp, copy_end)) { 4946 ret = -EFAULT; 4947 goto out_acct; 4948 } 4949 } 4950 if (args.flags != 0) { 4951 ret = -EINVAL; 4952 goto out_acct; 4953 } 4954 memset((char *)&args + copy_end_kernel, 0, 4955 sizeof(args) - copy_end_kernel); 4956 4958 &iov, &iter); 4959 if (ret < 0) 4960 goto out_acct; 4961 4962 if (iov_iter_count(&iter) == 0) { 4963 ret = 0; 4964 goto out_iov; 4965 } 4966 pos = args.offset; 4967 ret = rw_verify_area(READ, file, &pos, args.len); 4968 if (ret < 0) 4969 goto out_iov; 4970 4971 init_sync_kiocb(&kiocb, file); 4972 ret = kiocb_set_rw_flags(&kiocb, 0); 4973 if (ret) 4974 goto out_iov; 4975 kiocb.ki_pos = pos; 4976 4977 ret = btrfs_encoded_read(&kiocb, &iter, &args); 4978 if (ret >= 0) { 4979 fsnotify_access(file); 4980 if (copy_to_user(argp + copy_end, 4981 (char *)&args + copy_end_kernel, 4982 sizeof(args) - copy_end_kernel)) 4983 ret = -EFAULT; 4984 } 4985 4986 out_iov: 4987 kfree(iov); 4988 out_acct: 4989 if (ret > 0) 4990 add_rchar(current, ret); 4991 inc_syscr(current); 4992 return ret; 4993 } 4994 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org