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From: "Michael S. Tsirkin" <mst@redhat.com>
To: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: "David S. Miller" <davem@davemloft.net>,
	Tiwei Bie <tiwei.bie@intel.com>,
	virtualization@lists.linux-foundation.org
Subject: Re: [PATCH] virtio_ring: check desc == NULL when packed and indirect
Date: Mon, 27 Sep 2021 05:36:32 -0400	[thread overview]
Message-ID: <20210927053429-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20210927030618.81278-1-xuanzhuo@linux.alibaba.com>

On Mon, Sep 27, 2021 at 11:06:18AM +0800, Xuan Zhuo wrote:
> In the case of packed, use indirect desc, since desc is allocated by
> kmalloc_array(), we should check whether its return value is NULL.
> 
> Fixes: 1ce9e6055fa ("virtio_ring: introduce packed ring support")
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  drivers/virtio/virtio_ring.c | 27 ++++++++++++++++-----------
>  1 file changed, 16 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index dd95dfd85e98..7dd381eae725 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -1050,21 +1050,20 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
>  }
>  
>  static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> -				       struct scatterlist *sgs[],
> -				       unsigned int total_sg,
> -				       unsigned int out_sgs,
> -				       unsigned int in_sgs,
> -				       void *data,
> -				       gfp_t gfp)
> +					 struct scatterlist *sgs[],
> +					 struct vring_packed_desc *desc,
> +					 unsigned int total_sg,
> +					 unsigned int out_sgs,
> +					 unsigned int in_sgs,
> +					 void *data,
> +					 gfp_t gfp)
>  {
> -	struct vring_packed_desc *desc;
>  	struct scatterlist *sg;
>  	unsigned int i, n, err_idx;
>  	u16 head, id;
>  	dma_addr_t addr;
>  
>  	head = vq->packed.next_avail_idx;
> -	desc = alloc_indirect_packed(total_sg, gfp);
>  
>  	if (unlikely(vq->vq.num_free < 1)) {
>  		pr_debug("Can't add buf len 1 - avail = 0\n");
> @@ -1191,9 +1190,15 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
>  
>  	BUG_ON(total_sg == 0);
>  
> -	if (virtqueue_use_indirect(_vq, total_sg))
> -		return virtqueue_add_indirect_packed(vq, sgs, total_sg,
> -				out_sgs, in_sgs, data, gfp);
> +	if (virtqueue_use_indirect(_vq, total_sg)) {
> +		desc = alloc_indirect_packed(total_sg, gfp);
> +		if (desc) {
> +			return virtqueue_add_indirect_packed(vq, sgs, desc,
> +							     total_sg,
> +							     out_sgs, in_sgs,
> +							     data, gfp);
> +		}

Eschew {} for a single statement if conditions pls.


> +	}
>  
>  	head = vq->packed.next_avail_idx;
>  	avail_used_flags = vq->packed.avail_used_flags;
> -- 
> 2.31.0

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      parent reply	other threads:[~2021-09-27  9:36 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-27  3:06 [PATCH] virtio_ring: check desc == NULL when packed and indirect Xuan Zhuo
2021-09-27  3:20 ` Jason Wang
2021-09-27  3:25   ` Xuan Zhuo
2021-09-27  3:43     ` Jason Wang
2021-09-27  9:36 ` Michael S. Tsirkin [this message]

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