Re: [RFC v1 2/6] virtio/vsock: add support for virtio datagram

From: kernel test robot <lkp@intel.com>
To: kbuild-all@lists.01.org
Subject: Re: [RFC v1 2/6] virtio/vsock: add support for virtio datagram
Date: Wed, 16 Jun 2021 19:18:19 +0800	[thread overview]
Message-ID: <202106161905.rmuxHSC5-lkp@intel.com> (raw)
In-Reply-To: <20210609232501.171257-3-jiang.wang@bytedance.com>

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Hi Jiang,

[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on vhost/linux-next]
[also build test WARNING on tip/perf/core linus/master v5.13-rc6]
[cannot apply to next-20210615]
[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]

url:    https://github.com/0day-ci/linux/commits/Jiang-Wang/virtio-vsock-introduce-SOCK_DGRAM-support/20210616-120056
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: x86_64-randconfig-a015-20210615 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 64720f57bea6a6bf033feef4a5751ab9c0c3b401)
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
        # https://github.com/0day-ci/linux/commit/b156a0ad587c43dbfc98397f01b34fad15054bf0
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jiang-Wang/virtio-vsock-introduce-SOCK_DGRAM-support/20210616-120056
        git checkout b156a0ad587c43dbfc98397f01b34fad15054bf0
        # 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@intel.com>

All warnings (new ones prefixed by >>):

>> net/vmw_vsock/virtio_transport_common.c:416:6: warning: variable 'free_space' set but not used [-Wunused-but-set-variable]
           u32 free_space;
               ^
   1 warning generated.

vim +/free_space +416 net/vmw_vsock/virtio_transport_common.c

   408	
   409	static ssize_t
   410	virtio_transport_dgram_do_dequeue(struct vsock_sock *vsk,
   411							   struct msghdr *msg, size_t len)
   412	{
   413		struct virtio_vsock_sock *vvs = vsk->trans;
   414		struct virtio_vsock_pkt *pkt;
   415		size_t total = 0;
 > 416		u32 free_space;
   417		int err = -EFAULT;
   418	
   419		spin_lock_bh(&vvs->rx_lock);
   420		if (total < len && !list_empty(&vvs->rx_queue)) {
   421			pkt = list_first_entry(&vvs->rx_queue,
   422					       struct virtio_vsock_pkt, list);
   423	
   424			total = len;
   425			if (total > pkt->len - pkt->off)
   426				total = pkt->len - pkt->off;
   427			else if (total < pkt->len - pkt->off)
   428				msg->msg_flags |= MSG_TRUNC;
   429	
   430			/* sk_lock is held by caller so no one else can dequeue.
   431			 * Unlock rx_lock since memcpy_to_msg() may sleep.
   432			 */
   433			spin_unlock_bh(&vvs->rx_lock);
   434	
   435			err = memcpy_to_msg(msg, pkt->buf + pkt->off, total);
   436			if (err)
   437				return err;
   438	
   439			spin_lock_bh(&vvs->rx_lock);
   440	
   441			virtio_transport_dec_rx_pkt(vvs, pkt);
   442			list_del(&pkt->list);
   443			virtio_transport_free_pkt(pkt);
   444		}
   445	
   446		free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);
   447	
   448		spin_unlock_bh(&vvs->rx_lock);
   449	
   450		if (total > 0 && msg->msg_name) {
   451			/* Provide the address of the sender. */
   452			DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
   453	
   454			vsock_addr_init(vm_addr, le64_to_cpu(pkt->hdr.src_cid),
   455							le32_to_cpu(pkt->hdr.src_port));
   456			msg->msg_namelen = sizeof(*vm_addr);
   457		}
   458		return total;
   459	}
   460	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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