On Wed, Jul 19, 2023 at 06:33:05PM +0800, kernel test robot wrote: > Hi Xuan, > > kernel test robot noticed the following build warnings: > > [auto build test WARNING on v6.4] > [cannot apply to mst-vhost/linux-next linus/master v6.5-rc2 v6.5-rc1 next-20230719] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Xuan-Zhuo/virtio_ring-check-use_dma_api-before-unmap-desc-for-indirect/20230719-121424 > base: v6.4 > patch link: https://lore.kernel.org/r/20230719040422.126357-11-xuanzhuo%40linux.alibaba.com > patch subject: [PATCH vhost v12 10/10] virtio_net: merge dma operations when filling mergeable buffers > config: i386-randconfig-i006-20230718 (https://download.01.org/0day-ci/archive/20230719/202307191819.0tatknWa-lkp@xxxxxxxxx/config) > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 > reproduce: (https://download.01.org/0day-ci/archive/20230719/202307191819.0tatknWa-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/202307191819.0tatknWa-lkp@xxxxxxxxx/ > > All warnings (new ones prefixed by >>): > > drivers/net/virtio_net.c: In function 'virtnet_rq_init_one_sg': > >> drivers/net/virtio_net.c:624:41: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] > 624 | rq->sg[0].dma_address = (dma_addr_t)addr; > | ^ > drivers/net/virtio_net.c: In function 'virtnet_rq_alloc': > >> drivers/net/virtio_net.c:682:28: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] > 682 | *sg_addr = (void *)(dma->addr + alloc_frag->offset - sizeof(*dma)); > | ^ yea these casts are pretty creepy. I think it's possible dma_addr_t won't fit in a pointer or a pointer won't fit in dma_addr_t. > > vim +624 drivers/net/virtio_net.c > > 619 > 620 static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *addr, u32 len) > 621 { > 622 if (rq->do_dma) { > 623 sg_init_table(rq->sg, 1); > > 624 rq->sg[0].dma_address = (dma_addr_t)addr; > 625 rq->sg[0].length = len; > 626 } else { > 627 sg_init_one(rq->sg, addr, len); > 628 } > 629 } > 630 > 631 static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, > 632 void **sg_addr, gfp_t gfp) > 633 { > 634 struct page_frag *alloc_frag = &rq->alloc_frag; > 635 struct virtnet_rq_dma *dma; > 636 struct device *dev; > 637 void *buf, *head; > 638 dma_addr_t addr; > 639 > 640 if (unlikely(!skb_page_frag_refill(size, alloc_frag, gfp))) > 641 return NULL; > 642 > 643 head = (char *)page_address(alloc_frag->page); > 644 > 645 if (rq->do_dma) { > 646 dma = head; > 647 > 648 /* new pages */ > 649 if (!alloc_frag->offset) { > 650 if (rq->last_dma) { > 651 /* Now, the new page is allocated, the last dma > 652 * will not be used. So the dma can be unmapped > 653 * if the ref is 0. > 654 */ > 655 virtnet_rq_unmap(rq, rq->last_dma, 0); > 656 rq->last_dma = NULL; > 657 } > 658 > 659 dev = virtqueue_dma_dev(rq->vq); > 660 > 661 dma->len = alloc_frag->size - sizeof(*dma); > 662 > 663 addr = dma_map_single_attrs(dev, dma + 1, dma->len, DMA_FROM_DEVICE, 0); > 664 if (addr == DMA_MAPPING_ERROR) > 665 return NULL; > 666 > 667 dma->addr = addr; > 668 dma->need_sync = dma_need_sync(dev, addr); > 669 > 670 /* Add a reference to dma to prevent the entire dma from > 671 * being released during error handling. This reference > 672 * will be freed after the pages are no longer used. > 673 */ > 674 get_page(alloc_frag->page); > 675 dma->ref = 1; > 676 alloc_frag->offset = sizeof(*dma); > 677 > 678 rq->last_dma = dma; > 679 } > 680 > 681 ++dma->ref; > > 682 *sg_addr = (void *)(dma->addr + alloc_frag->offset - sizeof(*dma)); > 683 } else { > 684 *sg_addr = head + alloc_frag->offset; > 685 } > 686 > 687 buf = head + alloc_frag->offset; > 688 > 689 get_page(alloc_frag->page); > 690 alloc_frag->offset += size; > 691 > 692 return buf; > 693 } > 694 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki
