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Message-ID: <8cb9ad12-1426-43b6-830f-277d3b3b6a02@amd.com>
Date: Tue, 7 May 2024 16:12:14 +0700
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 1/1] iommu/amd: Fix sysfs leak in iommu init
Content-Language: en-US
To: "Kun(llfl)" <llfl@linux.alibaba.com>, Joerg Roedel <joro@8bytes.org>,
 Will Deacon <will@kernel.org>, Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Robin Murphy <robin.murphy@arm.com>, iommu@lists.linux.dev,
 linux-kernel@vger.kernel.org, Vasant Hegde <vasant.hegde@amd.com>
References: <4d516a6500ea0760e13cc19e2b14e663aa333518.1715048443.git.llfl@linux.alibaba.com>
From: "Suthikulpanit, Suravee" <suravee.suthikulpanit@amd.com>
In-Reply-To: <4d516a6500ea0760e13cc19e2b14e663aa333518.1715048443.git.llfl@linux.alibaba.com>
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Thanks for finding this sysfs leak.

On 5/7/2024 9:32 AM, Kun(llfl) wrote:
> During the iommu initialization, iommu_init_pci() adds sysfs nodes.
> However, these nodes aren't remove in free_iommu_resources() subsequently.
> 
> Fixes: ad8694bac410 ("iommu/amd: Move AMD IOMMU driver into subdirectory")

Actually, this commit only move the code into new directory structure. 
The original commit was:

commit 39ab9555c24110671f8dc671311a26e5c985b592
Author: Joerg Roedel <jroedel@suse.de>
Date:   Wed Feb 1 16:56:46 2017 +0100

     iommu: Add sysfs bindings for struct iommu_device

> Signed-off-by: Kun(llfl) <llfl@linux.alibaba.com>
> ---
>   drivers/iommu/amd/init.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
> index ac6754a85f35..624ea2549f64 100644
> --- a/drivers/iommu/amd/init.c
> +++ b/drivers/iommu/amd/init.c
> @@ -1678,8 +1678,15 @@ static void __init free_pci_segments(void)
>   	}
>   }
>   
> +static void __init free_sysfs(struct amd_iommu *iommu)
> +{
> +	if (iommu->iommu.dev)
> +		iommu_device_sysfs_remove(&iommu->iommu);
> +}
> +
>   static void __init free_iommu_one(struct amd_iommu *iommu)
>   {
> +	free_sysfs(iommu);

As part of the clean up, we also need to also call 
iommu_device_unregister() before iommu_device_sysfs_remove().

Thanks,
Suravee

>   	free_cwwb_sem(iommu);
>   	free_command_buffer(iommu);
>   	free_event_buffer(iommu);