Re: [PATCH vhost 4/6] virtio_net: big mode support premapped

[Dan Carpenter <dan.carpenter@linaro.org>]

Hi Xuan,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Xuan-Zhuo/virtio_ring-introduce-dma-map-api-for-page/20240411-105318
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link:    https://lore.kernel.org/r/20240411025127.51945-5-xuanzhuo%40linux.alibaba.com
patch subject: [PATCH vhost 4/6] virtio_net: big mode support premapped
config: i386-randconfig-141-20240414 (https://download.01.org/0day-ci/archive/20240414/202404141343.iPhKo7zd-lkp@intel.com/config)
compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0

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@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202404141343.iPhKo7zd-lkp@intel.com/

New smatch warnings:
drivers/net/virtio_net.c:485 give_pages() warn: impossible condition '((page->dma_addr) == (~0)) => (0-u32max == u64max)'

vim +485 drivers/net/virtio_net.c

e9d7417b97f420 Jason Wang      2012-12-07  481  static void give_pages(struct receive_queue *rq, struct page *page)
0a888fd1f6320d Mark McLoughlin 2008-11-16  482  {
9ab86bbcf8be75 Shirley Ma      2010-01-29  483  	struct page *end;
0a888fd1f6320d Mark McLoughlin 2008-11-16  484  
59e4bcf761eeba Xuan Zhuo       2024-04-11 @485  	if (page_dma_addr(page) == DMA_MAPPING_ERROR) {

(struct page)->dma_addr is unsigned long but DMA_MAPPING_ERROR is
dma_addr_t.

59e4bcf761eeba Xuan Zhuo       2024-04-11  486  		if (page_chain_map(rq, page)) {
59e4bcf761eeba Xuan Zhuo       2024-04-11  487  			__free_pages(page, 0);
59e4bcf761eeba Xuan Zhuo       2024-04-11  488  			return;
59e4bcf761eeba Xuan Zhuo       2024-04-11  489  		}
59e4bcf761eeba Xuan Zhuo       2024-04-11  490  	}
59e4bcf761eeba Xuan Zhuo       2024-04-11  491  
e9d7417b97f420 Jason Wang      2012-12-07  492  	/* Find end of list, sew whole thing into vi->rq.pages. */
590f79cf558cb4 Xuan Zhuo       2024-04-11  493  	for (end = page; page_chain_next(end); end = page_chain_next(end));
590f79cf558cb4 Xuan Zhuo       2024-04-11  494  
590f79cf558cb4 Xuan Zhuo       2024-04-11  495  	page_chain_add(end, rq->pages);
e9d7417b97f420 Jason Wang      2012-12-07  496  	rq->pages = page;
0a888fd1f6320d Mark McLoughlin 2008-11-16  497  }

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