Hi Xuan, kernel test robot noticed the following build warnings: url: https://github.com/intel-lab-lkp/linux/commits/Xuan-Zhuo/virtio_ring-introduce-vring_need_unmap_buffer/20240820-153644 base: net-next/main patch link: https://lore.kernel.org/r/20240820073330.9161-4-xuanzhuo%40linux.alibaba.com patch subject: [PATCH net-next 03/13] virtio_ring: packed: harden dma unmap for indirect config: x86_64-randconfig-161-20240820 (https://download.01.org/0day-ci/archive/20240821/202408210655.dx8v5uRW-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 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> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202408210655.dx8v5uRW-lkp@xxxxxxxxx/ New smatch warnings: drivers/virtio/virtio_ring.c:1634 detach_buf_packed() error: uninitialized symbol 'desc'. vim +/desc +1634 drivers/virtio/virtio_ring.c 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1594 static void detach_buf_packed(struct vring_virtqueue *vq, 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1595 unsigned int id, void **ctx) 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1596 { 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1597 struct vring_desc_state_packed *state = NULL; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1598 struct vring_packed_desc *desc; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1599 unsigned int i, curr; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1600 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1601 state = &vq->packed.desc_state[id]; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1602 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1603 /* Clear data ptr. */ 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1604 state->data = NULL; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1605 aeef9b4733c5c2 Jason Wang 2021-06-04 1606 vq->packed.desc_extra[state->last].next = vq->free_head; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1607 vq->free_head = id; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1608 vq->vq.num_free += state->num; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1609 d5c0ed17fea60c Xuan Zhuo 2024-02-23 1610 if (unlikely(vq->use_dma_api)) { 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1611 curr = id; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1612 for (i = 0; i < state->num; i++) { d80dc15bb6e76a Xuan Zhuo 2022-02-24 1613 vring_unmap_extra_packed(vq, 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1614 &vq->packed.desc_extra[curr]); aeef9b4733c5c2 Jason Wang 2021-06-04 1615 curr = vq->packed.desc_extra[curr].next; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1616 } 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1617 } 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1618 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1619 if (vq->indirect) { dfcc54f92ab71c Xuan Zhuo 2024-08-20 1620 struct vring_desc_extra *extra; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1621 u32 len; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1622 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1623 /* Free the indirect table, if any, now that it's unmapped. */ dfcc54f92ab71c Xuan Zhuo 2024-08-20 1624 extra = state->indir; dfcc54f92ab71c Xuan Zhuo 2024-08-20 1625 if (!extra) 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1626 return; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1627 de6a29c4b4c442 Xuan Zhuo 2024-08-20 1628 if (vring_need_unmap_buffer(vq)) { 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1629 len = vq->packed.desc_extra[id].len; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1630 for (i = 0; i < len / sizeof(struct vring_packed_desc); 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1631 i++) dfcc54f92ab71c Xuan Zhuo 2024-08-20 1632 vring_unmap_extra_packed(vq, &extra[i]); 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1633 } 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 @1634 kfree(desc); ^^^^ desc is never initialized/used. dfcc54f92ab71c Xuan Zhuo 2024-08-20 1635 state->indir = NULL; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1636 } else if (ctx) { dfcc54f92ab71c Xuan Zhuo 2024-08-20 1637 *ctx = state->indir; 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1638 } 1ce9e6055fa0a9 Tiwei Bie 2018-11-21 1639 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
