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Subject: Re: [PATCH 2/6] mm/hugetlb: fix WARN_ON(!kobj) in
 sysfs_create_group()
To:     Muchun Song <muchun.song@linux.dev>
CC:     Andrew Morton <akpm@linux-foundation.org>,
        <mike.kravetz@oracle.com>, Muchun Song <songmuchun@bytedance.com>,
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References: <20220816130553.31406-1-linmiaohe@huawei.com>
 <20220816130553.31406-3-linmiaohe@huawei.com>
 <AA374889-2C8B-4D8B-9542-A760267F00E4@linux.dev>
From:   Miaohe Lin <linmiaohe@huawei.com>
Message-ID: <a9dead65-0b68-e373-1785-7324b1378e24@huawei.com>
Date:   Wed, 17 Aug 2022 10:39:47 +0800
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On 2022/8/17 10:31, Muchun Song wrote:
> 
> 
>> On Aug 16, 2022, at 21:05, Miaohe Lin <linmiaohe@huawei.com> wrote:
>>
>> If sysfs_create_group() fails with hstate_attr_group, hstate_kobjs[hi]
>> will be set to NULL. Then it will be passed to sysfs_create_group() if
>> h->demote_order != 0 thus triggering WARN_ON(!kobj) check. Fix this by
>> making sure hstate_kobjs[hi] != NULL when calling sysfs_create_group.
>>
>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> 
> It’s better to add a Fixes tag here.

Will add it in next version. Thanks for your review and comment.

Thanks,
Miaohe Lin

> 
> Reviewed-by: Muchun Song <songmuchun@bytedance.com>
> 
> Thanks.
> 
> .
>