On 2020/2/11 下午9:52, Jason Gunthorpe wrote:
On Mon, Feb 10, 2020 at 11:56:08AM +0800, Jason Wang wrote:
+
+static struct vdpasim *vdpasim_create(void)
+{
+ struct vdpasim *vdpasim;
+ struct virtio_net_config *config;
+ struct vdpa_device *vdpa;
+ struct device *dev;
+ int ret = -ENOMEM;
+
+ vdpasim = kzalloc(sizeof(*vdpasim), GFP_KERNEL);
+ if (!vdpasim)
+ goto err_vdpa_alloc;
+
+ vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!vdpasim->buffer)
+ goto err_buffer_alloc;
+
+ vdpasim->iommu = vhost_iotlb_alloc(2048, 0);
+ if (!vdpasim->iommu)
+ goto err_iotlb;
+
+ config = &vdpasim->config;
+ config->mtu = 1500;
+ config->status = VIRTIO_NET_S_LINK_UP;
+ eth_random_addr(config->mac);
+
+ INIT_WORK(&vdpasim->work, vdpasim_work);
+ spin_lock_init(&vdpasim->lock);
+
+ vdpa = &vdpasim->vdpa;
+ vdpa->dev.release = vdpasim_release_dev;
The driver should not provide the release function.
Again the safest model is 'vdpa_alloc_device' which combines the
kzalloc and the vdpa_init_device() and returns something that is
error unwound with put_device()
The subsystem owns the release and does the kfree and other cleanup
like releasing the IDA.
So I think if we agree bus instead of class is used. vDPA bus can
provide a release function in vdpa_alloc_device()?
+ vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu);
+ vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu);
+
+ dev = &vdpa->dev;
+ dev->coherent_dma_mask = DMA_BIT_MASK(64);
+ set_dma_ops(dev, &vdpasim_dma_ops);
+
+ ret = vdpa_init_device(vdpa, &vdpasim_dev->dev, dev,
+ &vdpasim_net_config_ops);
+ if (ret)
+ goto err_init;
+
+ ret = vdpa_register_device(vdpa);
+ if (ret)
+ goto err_register;
See? This error unwind is now all wrong:
+
+ return vdpasim;
+
+err_register:
+ put_device(&vdpa->dev);
Double put_device
Yes.
+err_init:
+ vhost_iotlb_free(vdpasim->iommu);
+err_iotlb:
+ kfree(vdpasim->buffer);
+err_buffer_alloc:
+ kfree(vdpasim);
kfree after vdpa_init_device() is incorrect, as the put_device now
does kfree via release
Ok, will fix.
+static int __init vdpasim_dev_init(void)
+{
+ struct device *dev;
+ int ret = 0;
+
+ vdpasim_dev = kzalloc(sizeof(*vdpasim_dev), GFP_KERNEL);
+ if (!vdpasim_dev)
+ return -ENOMEM;
+
+ dev = &vdpasim_dev->dev;
+ dev->release = vdpasim_device_release;
+ dev_set_name(dev, "%s", VDPASIM_NAME);
+
+ ret = device_register(&vdpasim_dev->dev);
+ if (ret)
+ goto err_register;
+
+ if (!vdpasim_create())
+ goto err_register;
Wrong error unwind here too
Will fix.
Thanks
+ return 0;
+
+err_register:
+ kfree(vdpasim_dev);
+ vdpasim_dev = NULL;
+ return ret;
+}
Jason
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