tree: https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git fs_fuse_split head: 674d5faded4c40245ea02240e731aa82c7ab4c9e commit: 674d5faded4c40245ea02240e731aa82c7ab4c9e [5/5] fuse: alloc initial fuse_conn and fuse_mount config: powerpc-randconfig-r025-20210209 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476) 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 # install powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git/commit/... git remote add fuse https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git git fetch --no-tags fuse fs_fuse_split git checkout 674d5faded4c40245ea02240e731aa82c7ab4c9e # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc 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 >>): fuse_conn_put(fc); ^~ fs/fuse/inode.c:1466:22: note: initialize the variable 'fc' to silence this warning struct fuse_conn *fc; ^ = NULL 1 warning generated. vim +/fc +1503 fs/fuse/inode.c 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1460 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1461 static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1462 { 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1463 struct fuse_fs_context *ctx = fsc->fs_private; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1464 struct file *file; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1465 int err; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1466 struct fuse_conn *fc; fcee216beb9c15 Max Reitz 2020-05-06 1467 struct fuse_mount *fm; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1468 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1469 err = -EINVAL; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1470 file = fget(ctx->fd); 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1471 if (!file) 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1472 goto err; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1473 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1474 /* 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1475 * Require mount to happen from the same user namespace which 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1476 * opened /dev/fuse to prevent potential attacks. 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1477 */ 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1478 if ((file->f_op != &fuse_dev_operations) || 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1479 (file->f_cred->user_ns != sb->s_user_ns)) 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1480 goto err_fput; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1481 ctx->fudptr = &file->private_data; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1482 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1483 err = -ENOMEM; 674d5faded4c40 Miklos Szeredi 2021-02-11 1484 fm = fuse_conn_new(sb->s_user_ns, &fuse_dev_fiq_ops, NULL, NULL, NULL); 674d5faded4c40 Miklos Szeredi 2021-02-11 1485 if (!fm) fcee216beb9c15 Max Reitz 2020-05-06 1486 goto err_fput; fcee216beb9c15 Max Reitz 2020-05-06 1487 fcee216beb9c15 Max Reitz 2020-05-06 1488 sb->s_fs_info = fm; 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1489 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1490 err = fuse_fill_super_common(sb, ctx); 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1491 if (err) 0cc2656cdb0b1f Stefan Hajnoczi 2018-06-13 1492 goto err_put_conn; 0720b315976447 Miklos Szeredi 2006-04-10 1493 /* 0720b315976447 Miklos Szeredi 2006-04-10 1494 * atomic_dec_and_test() in fput() provides the necessary 0720b315976447 Miklos Szeredi 2006-04-10 1495 * memory barrier for file->private_data to be visible on all 0720b315976447 Miklos Szeredi 2006-04-10 1496 * CPUs after this 0720b315976447 Miklos Szeredi 2006-04-10 1497 */ 0720b315976447 Miklos Szeredi 2006-04-10 1498 fput(file); fcee216beb9c15 Max Reitz 2020-05-06 1499 fuse_send_init(get_fuse_mount_super(sb)); d8a5ba45457e4a Miklos Szeredi 2005-09-09 1500 return 0; d8a5ba45457e4a Miklos Szeredi 2005-09-09 1501 c2b8f006909b9b Miklos Szeredi 2009-01-26 1502 err_put_conn: 514b5e3ff45e6c Miklos Szeredi 2020-11-11 @1503 fuse_conn_put(fc); 514b5e3ff45e6c Miklos Szeredi 2020-11-11 1504 kfree(fm); 543b8f8662fe6d Tetsuo Handa 2018-05-01 1505 sb->s_fs_info = NULL; c2b8f006909b9b Miklos Szeredi 2009-01-26 1506 err_fput: c2b8f006909b9b Miklos Szeredi 2009-01-26 1507 fput(file); c2b8f006909b9b Miklos Szeredi 2009-01-26 1508 err: d8a5ba45457e4a Miklos Szeredi 2005-09-09 1509 return err; d8a5ba45457e4a Miklos Szeredi 2005-09-09 1510 } d8a5ba45457e4a Miklos Szeredi 2005-09-09 1511 :::::: The code at line 1503 was first introduced by commit :::::: 514b5e3ff45e6cfc39cfa7c094727d8e6d885986 fuse: get rid of fuse_mount refcount :::::: TO: Miklos Szeredi <mszeredi(a)redhat.com&gt; :::::: CC: Miklos Szeredi <mszeredi(a)redhat.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org