tree: https://github.com/jgunthorpe/linux for-yishai head: f2e248975954bcc9b76fc51c917a950d2757f930 commit: 5ba994930f2ac492c86cfd9ef9da78c0fcb34809 [17/22] RDMA/mlx5: Move mlx5_ib_cont_pages() to the creation of the mlx5_ib_mr config: x86_64-randconfig-a006-20200818 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 4deda57106f7c9b982a49cb907c33e3966c8de7f) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu git checkout 5ba994930f2ac492c86cfd9ef9da78c0fcb34809 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 (IS_ERR(mr->umem)) { ^~~~~~~~~~~~~~~~ drivers/infiniband/hw/mlx5/mr.c:1581:9: note: uninitialized use occurs here return err; ^~~ drivers/infiniband/hw/mlx5/mr.c:1521:3: note: remove the 'if' if its condition is always false if (IS_ERR(mr->umem)) { ^~~~~~~~~~~~~~~~~~~~~~~ drivers/infiniband/hw/mlx5/mr.c:1492:9: note: initialize the variable 'err' to silence this warning int err; ^ = 0 1 warning generated. # https://github.com/jgunthorpe/linux/commit/5ba994930f2ac492c86cfd9ef9da78... git remote add jgunthorpe https://github.com/jgunthorpe/linux git fetch --no-tags jgunthorpe for-yishai git checkout 5ba994930f2ac492c86cfd9ef9da78c0fcb34809 vim +1521 drivers/infiniband/hw/mlx5/mr.c 1479 1480 int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start, 1481 u64 length, u64 virt_addr, int new_access_flags, 1482 struct ib_pd *new_pd, struct ib_udata *udata) 1483 { 1484 struct mlx5_ib_dev *dev = to_mdev(ib_mr->device); 1485 struct mlx5_ib_mr *mr = to_mmr(ib_mr); 1486 struct ib_pd *pd = (flags & IB_MR_REREG_PD) ? new_pd : ib_mr->pd; 1487 int access_flags = flags & IB_MR_REREG_ACCESS ? 1488 new_access_flags : 1489 mr->access_flags; 1490 int upd_flags = 0; 1491 u64 addr, len; 1492 int err; 1493 1494 mlx5_ib_dbg(dev, "start 0x%llx, virt_addr 0x%llx, length 0x%llx, access_flags 0x%x\n", 1495 start, virt_addr, length, access_flags); 1496 1497 if (!mr->umem) 1498 return -EINVAL; 1499 1500 if (is_odp_mr(mr)) 1501 return -EOPNOTSUPP; 1502 1503 if (flags & IB_MR_REREG_TRANS) { 1504 addr = virt_addr; 1505 len = length; 1506 } else { 1507 addr = mr->umem->address; 1508 len = mr->umem->length; 1509 } 1510 1511 if (flags != IB_MR_REREG_PD) { 1512 /* 1513 * Replace umem. This needs to be done whether or not UMR is 1514 * used. 1515 */ 1516 flags |= IB_MR_REREG_TRANS; 1517 atomic_sub(ib_umem_num_pages(mr->umem), 1518 &dev->mdev->priv.reg_pages); 1519 ib_umem_release(mr->umem); 1520 mr->umem = mr_umem_get(dev, addr, len, access_flags); 1522 mr->umem = NULL; 1523 goto err; 1524 } 1525 atomic_add(ib_umem_num_pages(mr->umem), 1526 &dev->mdev->priv.reg_pages); 1527 } 1528 1529 if (!mlx5_ib_can_use_umr(dev, mr->umem->length, true, access_flags) || 1530 (flags & IB_MR_REREG_TRANS && !use_umr_mtt_update(mr, addr, len))) { 1531 /* 1532 * UMR can't be used - MKey needs to be replaced. 1533 */ 1534 if (mr->cache_ent) 1535 detach_mr_from_cache(mr); 1536 err = destroy_mkey(dev, mr); 1537 if (err) 1538 goto err; 1539 1540 mr = reg_create(ib_mr, pd, mr->umem, addr, access_flags, true); 1541 if (IS_ERR(mr)) { 1542 err = PTR_ERR(mr); 1543 mr = to_mmr(ib_mr); 1544 goto err; 1545 } 1546 } else { 1547 /* 1548 * Send a UMR WQE 1549 */ 1550 mr->ibmr.pd = pd; 1551 mr->access_flags = access_flags; 1552 mr->mmkey.iova = addr; 1553 mr->mmkey.size = len; 1554 mr->mmkey.pd = to_mpd(pd)->pdn; 1555 1556 if (flags & IB_MR_REREG_TRANS) { 1557 upd_flags = MLX5_IB_UPD_XLT_ADDR; 1558 if (flags & IB_MR_REREG_PD) 1559 upd_flags |= MLX5_IB_UPD_XLT_PD; 1560 if (flags & IB_MR_REREG_ACCESS) 1561 upd_flags |= MLX5_IB_UPD_XLT_ACCESS; 1562 err = mlx5_ib_update_xlt(mr, 0, mlx5_mr_num_pages(mr), 1563 mr->page_shift, upd_flags); 1564 } else { 1565 err = rereg_umr(pd, mr, access_flags, flags); 1566 } 1567 1568 if (err) 1569 goto err; 1570 } 1571 1572 set_mr_fields(dev, mr, len, access_flags); 1573 1574 return 0; 1575 1576 err: 1577 ib_umem_release(mr->umem); 1578 mr->umem = NULL; 1579 1580 clean_mr(dev, mr); 1581 return err; 1582 } 1583 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org