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Subject: Re: [PATCH] driver core: Call dma_cleanup() on the test_remove path
To:     Jason Gunthorpe <jgg@nvidia.com>
CC:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Joerg Roedel <jroedel@suse.de>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <0-v1-8fd93768dbcf+19b-really_probe_dma_cleanup_jgg@nvidia.com>
From:   Zenghui Yu <yuzenghui@huawei.com>
Message-ID: <ce997cca-32c2-fc04-b84c-b97e6ccea4ca@huawei.com>
Date:   Mon, 24 Jul 2023 11:56:09 +0800
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+Cc: LKML

On 2023/7/22 0:20, Jason Gunthorpe wrote:
> When test_remove is enabled really_probe() does not properly pair
> dma_configure() with dma_remove(), it will end up calling dma_configure()
> twice. This corrupts the owner_cnt and renders the group unusable with
> VFIO/etc.
> 
> Add the missing cleanup before going back to re_probe.
> 
> Fixes: 25f3bcfc54bc ("driver core: Add dma_cleanup callback in bus_type")
> Reported-by: Zenghui Yu <yuzenghui@huawei.com>
> Closes: https://lore.kernel.org/all/6472f254-c3c4-8610-4a37-8d9dfdd54ce8@huawei.com/
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  drivers/base/dd.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 878aa7646b37e4..a528cec24264ab 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -693,6 +693,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  
>  		device_remove(dev);
>  		driver_sysfs_remove(dev);
> +		if (dev->bus && dev->bus->dma_cleanup)
> +			dev->bus->dma_cleanup(dev);
>  		device_unbind_cleanup(dev);
>  
>  		goto re_probe;
> 
> base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5
> 

Tested-by: Zenghui Yu <yuzenghui@huawei.com>

Thanks,
Zenghui