diff mbox series

[04/17] vhost: prep vhost_dev_init users to handle failures

Message ID 1603326903-27052-5-git-send-email-michael.christie@oracle.com (mailing list archive)
State New, archived
Headers show
Series vhost: fix scsi cmd handling and cgroup support | expand

Commit Message

Mike Christie Oct. 22, 2020, 12:34 a.m. UTC 
This is just a prep patch to get vhost_dev_init callers ready to handle
the next patch where the function can fail. In this patch vhost_dev_init
just returns 0, but I think it's easier to check for goto/error handling
errors separated from the next patch.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/vhost/net.c   | 11 +++++++----
 drivers/vhost/scsi.c  |  7 +++++--
 drivers/vhost/test.c  |  9 +++++++--
 drivers/vhost/vdpa.c  |  7 +++++--
 drivers/vhost/vhost.c | 14 ++++++++------
 drivers/vhost/vhost.h | 10 +++++-----
 drivers/vhost/vsock.c |  9 ++++++---
 7 files changed, 43 insertions(+), 24 deletions(-)

Comments

kernel test robot Oct. 22, 2020, 5:22 a.m. UTC | #1 
Hi Mike,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on vhost/linux-next]
[also build test WARNING on v5.9 next-20201021]
[cannot apply to target/for-next]
[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/Mike-Christie/vhost-fix-scsi-cmd-handling-and-cgroup-support/20201022-083844
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: x86_64-randconfig-a013-20201021 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project ee6abef5323d59b983129bf3514ef6775d1d6cd5)
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/6e1629548d318c2c9af7490379a3c9d7e3cba0d5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Mike-Christie/vhost-fix-scsi-cmd-handling-and-cgroup-support/20201022-083844
        git checkout 6e1629548d318c2c9af7490379a3c9d7e3cba0d5
        # 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 >>):

>> drivers/vhost/vsock.c:633:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
           if (vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/vhost/vsock.c:648:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   drivers/vhost/vsock.c:633:2: note: remove the 'if' if its condition is always false
           if (vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/vhost/vsock.c:609:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
   1 warning generated.

vim +633 drivers/vhost/vsock.c

   604	
   605	static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
   606	{
   607		struct vhost_virtqueue **vqs;
   608		struct vhost_vsock *vsock;
   609		int ret;
   610	
   611		/* This struct is large and allocation could fail, fall back to vmalloc
   612		 * if there is no other way.
   613		 */
   614		vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
   615		if (!vsock)
   616			return -ENOMEM;
   617	
   618		vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
   619		if (!vqs) {
   620			ret = -ENOMEM;
   621			goto out;
   622		}
   623	
   624		vsock->guest_cid = 0; /* no CID assigned yet */
   625	
   626		atomic_set(&vsock->queued_replies, 0);
   627	
   628		vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
   629		vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
   630		vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
   631		vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
   632	
 > 633		if (vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
   634				   UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
   635				   VHOST_VSOCK_WEIGHT, true, NULL))
   636			goto err_dev_init;
   637	
   638		file->private_data = vsock;
   639		spin_lock_init(&vsock->send_pkt_list_lock);
   640		INIT_LIST_HEAD(&vsock->send_pkt_list);
   641		vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
   642		return 0;
   643	
   644	err_dev_init:
   645		kfree(vqs);
   646	out:
   647		vhost_vsock_free(vsock);
   648		return ret;
   649	}
   650	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Mike Christie Oct. 23, 2020, 4:15 p.m. UTC | #2 
On 10/21/20 7:34 PM, Mike Christie wrote:
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index 86617bb..63ba363 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -1632,14 +1632,17 @@ static int vhost_scsi_open(struct inode *inode, struct file *f)
>   		vqs[i] = &vs->vqs[i].vq;
>   		vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
>   	}
> -	vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV,
> -		       VHOST_SCSI_WEIGHT, 0, true, NULL);
> +	if (vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV,
> +			   VHOST_SCSI_WEIGHT, 0, true, NULL))


> diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
> index f40205f..a1a35e1 100644
> --- a/drivers/vhost/vsock.c
> +++ b/drivers/vhost/vsock.c
> @@ -630,9 +630,10 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
>   	vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
>   	vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
>   
> -	vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
> -		       UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
> -		       VHOST_VSOCK_WEIGHT, true, NULL);
> +	if (vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
> +			   UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
>

Just giving myself a review comment, so it doesn't happen like last time 
where multiple people waste their time and hit the same issue :)

I will fix this one found by the kernel test robot and fix up a similar 
scsi.c case where the return value is not propagated above.
Jason Wang Nov. 2, 2020, 5:57 a.m. UTC | #3 
On 2020/10/22 上午8:34, Mike Christie wrote:
> This is just a prep patch to get vhost_dev_init callers ready to handle
> the next patch where the function can fail. In this patch vhost_dev_init
> just returns 0, but I think it's easier to check for goto/error handling
> errors separated from the next patch.
>
> Signed-off-by: Mike Christie<michael.christie@oracle.com>
> ---
>   drivers/vhost/net.c   | 11 +++++++----
>   drivers/vhost/scsi.c  |  7 +++++--
>   drivers/vhost/test.c  |  9 +++++++--
>   drivers/vhost/vdpa.c  |  7 +++++--
>   drivers/vhost/vhost.c | 14 ++++++++------
>   drivers/vhost/vhost.h | 10 +++++-----
>   drivers/vhost/vsock.c |  9 ++++++---
>   7 files changed, 43 insertions(+), 24 deletions(-)


Acked-by: Jason Wang <jasowang@redhat.com>
Dan Carpenter Nov. 3, 2020, 10:04 a.m. UTC | #4 
Hi Mike,

url:    https://github.com/0day-ci/linux/commits/Mike-Christie/vhost-fix-scsi-cmd-handling-and-cgroup-support/20201022-083844
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: i386-randconfig-m021-20201101 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

smatch warnings:
drivers/vhost/vsock.c:648 vhost_vsock_dev_open() error: uninitialized symbol 'ret'.

vim +/ret +648 drivers/vhost/vsock.c

433fc58e6bf2c8b Asias He        2016-07-28  605  static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
433fc58e6bf2c8b Asias He        2016-07-28  606  {
433fc58e6bf2c8b Asias He        2016-07-28  607  	struct vhost_virtqueue **vqs;
433fc58e6bf2c8b Asias He        2016-07-28  608  	struct vhost_vsock *vsock;
433fc58e6bf2c8b Asias He        2016-07-28  609  	int ret;
433fc58e6bf2c8b Asias He        2016-07-28  610  
433fc58e6bf2c8b Asias He        2016-07-28  611  	/* This struct is large and allocation could fail, fall back to vmalloc
433fc58e6bf2c8b Asias He        2016-07-28  612  	 * if there is no other way.
433fc58e6bf2c8b Asias He        2016-07-28  613  	 */
dcda9b04713c3f6 Michal Hocko    2017-07-12  614  	vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
433fc58e6bf2c8b Asias He        2016-07-28  615  	if (!vsock)
433fc58e6bf2c8b Asias He        2016-07-28  616  		return -ENOMEM;
433fc58e6bf2c8b Asias He        2016-07-28  617  
433fc58e6bf2c8b Asias He        2016-07-28  618  	vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
433fc58e6bf2c8b Asias He        2016-07-28  619  	if (!vqs) {
433fc58e6bf2c8b Asias He        2016-07-28  620  		ret = -ENOMEM;
433fc58e6bf2c8b Asias He        2016-07-28  621  		goto out;
433fc58e6bf2c8b Asias He        2016-07-28  622  	}
433fc58e6bf2c8b Asias He        2016-07-28  623  
a72b69dc083a931 Stefan Hajnoczi 2017-11-09  624  	vsock->guest_cid = 0; /* no CID assigned yet */
a72b69dc083a931 Stefan Hajnoczi 2017-11-09  625  
433fc58e6bf2c8b Asias He        2016-07-28  626  	atomic_set(&vsock->queued_replies, 0);
433fc58e6bf2c8b Asias He        2016-07-28  627  
433fc58e6bf2c8b Asias He        2016-07-28  628  	vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
433fc58e6bf2c8b Asias He        2016-07-28  629  	vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
433fc58e6bf2c8b Asias He        2016-07-28  630  	vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
433fc58e6bf2c8b Asias He        2016-07-28  631  	vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
433fc58e6bf2c8b Asias He        2016-07-28  632  
6e1629548d318c2 Mike Christie   2020-10-21  633  	if (vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
e82b9b0727ff6d6 Jason Wang      2019-05-17  634  			   UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
6e1629548d318c2 Mike Christie   2020-10-21  635  			   VHOST_VSOCK_WEIGHT, true, NULL))
6e1629548d318c2 Mike Christie   2020-10-21  636  		goto err_dev_init;
                                                                ^^^^^^^^^^^^^^^^^
"ret" needs to be set here.

433fc58e6bf2c8b Asias He        2016-07-28  637  
433fc58e6bf2c8b Asias He        2016-07-28  638  	file->private_data = vsock;
433fc58e6bf2c8b Asias He        2016-07-28  639  	spin_lock_init(&vsock->send_pkt_list_lock);
433fc58e6bf2c8b Asias He        2016-07-28  640  	INIT_LIST_HEAD(&vsock->send_pkt_list);
433fc58e6bf2c8b Asias He        2016-07-28  641  	vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
433fc58e6bf2c8b Asias He        2016-07-28  642  	return 0;
433fc58e6bf2c8b Asias He        2016-07-28  643  
6e1629548d318c2 Mike Christie   2020-10-21  644  err_dev_init:
6e1629548d318c2 Mike Christie   2020-10-21  645  	kfree(vqs);
433fc58e6bf2c8b Asias He        2016-07-28  646  out:
433fc58e6bf2c8b Asias He        2016-07-28  647  	vhost_vsock_free(vsock);
433fc58e6bf2c8b Asias He        2016-07-28 @648  	return ret;
433fc58e6bf2c8b Asias He        2016-07-28  649  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 831d824..fd30b53 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1316,10 +1316,11 @@  static int vhost_net_open(struct inode *inode, struct file *f)
 		n->vqs[i].rx_ring = NULL;
 		vhost_net_buf_init(&n->vqs[i].rxq);
 	}
-	vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX,
-		       UIO_MAXIOV + VHOST_NET_BATCH,
-		       VHOST_NET_PKT_WEIGHT, VHOST_NET_WEIGHT, true,
-		       NULL);
+	if (vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX,
+			   UIO_MAXIOV + VHOST_NET_BATCH,
+			   VHOST_NET_PKT_WEIGHT, VHOST_NET_WEIGHT, true,
+			   NULL))
+		goto err_dev_init;
 
 	vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev);
 	vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev);
@@ -1330,6 +1331,8 @@  static int vhost_net_open(struct inode *inode, struct file *f)
 
 	return 0;
 
+err_dev_init:
+	kfree(xdp);
 err_xdp:
 	kfree(queue);
 err_queue:
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 86617bb..63ba363 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1632,14 +1632,17 @@  static int vhost_scsi_open(struct inode *inode, struct file *f)
 		vqs[i] = &vs->vqs[i].vq;
 		vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
 	}
-	vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV,
-		       VHOST_SCSI_WEIGHT, 0, true, NULL);
+	if (vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV,
+			   VHOST_SCSI_WEIGHT, 0, true, NULL))
+		goto err_dev_init;
 
 	vhost_scsi_init_inflight(vs, NULL);
 
 	f->private_data = vs;
 	return 0;
 
+err_dev_init:
+	kfree(vqs);
 err_vqs:
 	kvfree(vs);
 err_vs:
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index a09dedc..c255ae5 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -119,12 +119,17 @@  static int vhost_test_open(struct inode *inode, struct file *f)
 	dev = &n->dev;
 	vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
 	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
-	vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,
-		       VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT, true, NULL);
+	if (vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,
+			   VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT, true, NULL)
+		goto err_dev_init;
 
 	f->private_data = n;
 
 	return 0;
+
+err_dev_init:
+	kfree(vqs);
+	return -ENOMEM;
 }
 
 static void *vhost_test_stop_vq(struct vhost_test *n,
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index a2dbc85..9c8a686 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -810,8 +810,10 @@  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 		vqs[i] = &v->vqs[i];
 		vqs[i]->handle_kick = handle_vq_kick;
 	}
-	vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
-		       vhost_vdpa_process_iotlb_msg);
+	r = vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
+			   vhost_vdpa_process_iotlb_msg);
+	if (r)
+		goto err_dev_init;
 
 	dev->iotlb = vhost_iotlb_alloc(0, 0);
 	if (!dev->iotlb) {
@@ -829,6 +831,7 @@  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 
 err_init_iotlb:
 	vhost_dev_cleanup(&v->vdev);
+err_dev_init:
 	kfree(vqs);
 err:
 	atomic_dec(&v->opened);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 6818f71..b35229e 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -458,12 +458,12 @@  static size_t vhost_get_desc_size(struct vhost_virtqueue *vq,
 	return sizeof(*vq->desc) * num;
 }
 
-void vhost_dev_init(struct vhost_dev *dev,
-		    struct vhost_virtqueue **vqs, int nvqs,
-		    int iov_limit, int weight, int byte_weight,
-		    bool use_worker,
-		    int (*msg_handler)(struct vhost_dev *dev,
-				       struct vhost_iotlb_msg *msg))
+int vhost_dev_init(struct vhost_dev *dev,
+		   struct vhost_virtqueue **vqs, int nvqs,
+		   int iov_limit, int weight, int byte_weight,
+		   bool use_worker,
+		   int (*msg_handler)(struct vhost_dev *dev,
+				      struct vhost_iotlb_msg *msg))
 {
 	struct vhost_virtqueue *vq;
 	int i;
@@ -500,6 +500,8 @@  void vhost_dev_init(struct vhost_dev *dev,
 			vhost_poll_init(&vq->poll, vq->handle_kick,
 					EPOLLIN, dev);
 	}
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(vhost_dev_init);
 
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 1365f33..9ad34b1 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -167,11 +167,11 @@  struct vhost_dev {
 };
 
 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
-void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
-		    int nvqs, int iov_limit, int weight, int byte_weight,
-		    bool use_worker,
-		    int (*msg_handler)(struct vhost_dev *dev,
-				       struct vhost_iotlb_msg *msg));
+int vhost_dev_init(struct vhost_dev *dev, struct vhost_virtqueue **vqs,
+		   int nvqs, int iov_limit, int weight, int byte_weight,
+		   bool use_worker,
+		   int (*msg_handler)(struct vhost_dev *dev,
+				      struct vhost_iotlb_msg *msg));
 long vhost_dev_set_owner(struct vhost_dev *dev);
 bool vhost_dev_has_owner(struct vhost_dev *dev);
 long vhost_dev_check_owner(struct vhost_dev *);
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index f40205f..a1a35e1 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -630,9 +630,10 @@  static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
 	vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
 	vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
 
-	vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
-		       UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
-		       VHOST_VSOCK_WEIGHT, true, NULL);
+	if (vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
+			   UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
+			   VHOST_VSOCK_WEIGHT, true, NULL))
+		goto err_dev_init;
 
 	file->private_data = vsock;
 	spin_lock_init(&vsock->send_pkt_list_lock);
@@ -640,6 +641,8 @@  static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
 	vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
 	return 0;
 
+err_dev_init:
+	kfree(vqs);
 out:
 	vhost_vsock_free(vsock);
 	return ret;