On Tue, Nov 10, 2020 at 01:41:12PM -0800, Jianxin Xiong wrote: > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device, > + unsigned long offset, size_t size, > + int fd, int access, > + const struct dma_buf_attach_ops *ops) > +{ > + struct dma_buf *dmabuf; > + struct ib_umem_dmabuf *umem_dmabuf; > + struct ib_umem *umem; > + unsigned long end; > + long ret; > + > + if (check_add_overflow(offset, (unsigned long)size, &end)) > + return ERR_PTR(-EINVAL); > + > + if (unlikely(PAGE_ALIGN(end) < PAGE_SIZE)) > + return ERR_PTR(-EINVAL); This is weird, what does it do? > + > + if (unlikely(!ops || !ops->move_notify)) > + return ERR_PTR(-EINVAL); > + > + umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL); > + if (!umem_dmabuf) > + return ERR_PTR(-ENOMEM); > + > + umem = &umem_dmabuf->umem; > + umem->ibdev = device; > + umem->length = size; > + umem->address = offset; > + umem->writable = ib_access_writable(access); > + umem->is_dmabuf = 1; > + > + if (unlikely(!ib_umem_num_pages(umem))) { > + ret = -EINVAL; > + goto out_free_umem; > + } > + > + dmabuf = dma_buf_get(fd); > + if (IS_ERR(dmabuf)) { > + ret = PTR_ERR(dmabuf); > + goto out_free_umem; > + } > + > + if (dmabuf->size < offset + size) { > + ret = -EINVAL; > + goto out_release_dmabuf; offset + size == end, already computed, in fact move this above the kzalloc Jason