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Date:   Fri, 15 Jul 2022 09:49:27 +0200
From:   Joerg Roedel <joro@8bytes.org>
To:     Yang Yingliang <yangyingliang@huawei.com>
Cc:     linux-kernel@vger.kernel.org, iommu@lists.linux.dev,
        iommu@lists.linux-foundation.org, will@kernel.org,
        yf.wang@mediatek.com, Robin Murphy <robin.murphy@arm.com>
Subject: Re: [PATCH -next] iommu/dma: Fix missing mutex_init() in
 iommu_get_msi_cookie()
Message-ID: <YtEcB6717b3d5suQ@8bytes.org>
References: <20220627085533.1469141-1-yangyingliang@huawei.com>
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In-Reply-To: <20220627085533.1469141-1-yangyingliang@huawei.com>
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Adding Robin.

On Mon, Jun 27, 2022 at 04:55:33PM +0800, Yang Yingliang wrote:
> cookie_alloc() is called by iommu_get_dma_cookie() and iommu_get_msi_cookie(),
> but the mutex is only initialized in iommu_get_dma_cookie(), move mutex_init()
> into cookie_alloc() to make sure the mutex will be initialized.
> 
> Fixes: ac9a5d522bb8 ("iommu/dma: Fix race condition during iova_domain initialization")
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>  drivers/iommu/dma-iommu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 1910f4f1612b..e29157380c48 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -294,6 +294,7 @@ static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
>  	if (cookie) {
>  		INIT_LIST_HEAD(&cookie->msi_page_list);
>  		cookie->type = type;
> +		mutex_init(&cookie->mutex);
>  	}
>  	return cookie;
>  }
> @@ -311,7 +312,6 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
>  	if (!domain->iova_cookie)
>  		return -ENOMEM;
>  
> -	mutex_init(&domain->iova_cookie->mutex);
>  	return 0;
>  }
>  
> -- 
> 2.25.1