Re: [PATCH v9 16/17] vduse: Introduce VDUSE - vDPA Device in Userspace
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From: Dan Carpenter <hidden>
Date: 2021-07-13 13:28:36
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kvm, linux-fsdevel, linux-iommu, lkml, virtualization
On Tue, Jul 13, 2021 at 04:46:55PM +0800, Xie Yongji wrote:
quoted hunk ↗ jump to hunk
+static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name) +{ + struct vduse_vdpa *vdev; + int ret; + + if (dev->vdev) + return -EEXIST; + + vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev, + &vduse_vdpa_config_ops, name, true); + if (!vdev) + return -ENOMEM;
This should be an IS_ERR() check instead of a NULL check. The vdpa_alloc_device() macro is doing something very complicated but I'm not sure what. It calls container_of() and that looks buggy until you spot the BUILD_BUG_ON_ZERO() compile time assert which ensures that the container_of() is a no-op. Only one of the callers checks for error pointers correctly so maybe it's too complicated or maybe there should be better documentation. regards, dan carpenter