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Message-ID: <7f1cfee4-c6de-ea59-0aa9-9bd55054fb22@redhat.com>
Date:   Tue, 20 Sep 2022 15:22:38 +0200
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Subject: Re: [PATCH] mm/secretmem: remove reduntant return value
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To:     xiujianfeng <xiujianfeng@huawei.com>, akpm@linux-foundation.org
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Binyi Han <dantengknight@gmail.com>
References: <20220920012205.246217-1-xiujianfeng@huawei.com>
 <3196b824-bcee-0c44-bfd3-f6cd8a1e6719@redhat.com>
 <c4e99ea3-302d-b173-27f1-92c38ddaca8c@huawei.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <c4e99ea3-302d-b173-27f1-92c38ddaca8c@huawei.com>
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On 20.09.22 14:35, xiujianfeng wrote:
> Hi,
> 
> 在 2022/9/20 20:10, David Hildenbrand 写道:
>> On 20.09.22 03:22, Xiu Jianfeng wrote:
>>> The return value @ret is always 0, so remove it and return 0 directly.
>>>
>>> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
>>> ---
>>>    mm/secretmem.c | 6 ++----
>>>    1 file changed, 2 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/mm/secretmem.c b/mm/secretmem.c
>>> index 6a44efb673b2..04c3ac9448a1 100644
>>> --- a/mm/secretmem.c
>>> +++ b/mm/secretmem.c
>>> @@ -278,10 +278,8 @@ static struct file_system_type secretmem_fs = {
>>>    static int __init secretmem_init(void)
>>>    {
>>> -    int ret = 0;
>>> -
>>>        if (!secretmem_enable)
>>> -        return ret;
>>> +        return 0;
>>>        secretmem_mnt = kern_mount(&secretmem_fs);
>>>        if (IS_ERR(secretmem_mnt))
>>
>> On top of which tree is that?
>>
>> 6.0-rc6 has here:
>>
>> if (IS_ERR(secretmem_mnt))
>>       ret = PTR_ERR(secretmem_mnt);
>>
> Sorry, it's on linux-next tree, I should have used [PATCH -next]:)
> 

Maybe this change should be squashed into the patch from Binyi directly:


commit 4eb5bbde3ccb710d3b85bfb13466612e56393369 (mm/mm-hotfixes-stable)
Author: Binyi Han <dantengknight@gmail.com>
Date:   Sun Sep 4 00:46:47 2022 -0700

     mm: fix dereferencing possible ERR_PTR
     
     Smatch checker complains that 'secretmem_mnt' dereferencing possible
     ERR_PTR().  Let the function return if 'secretmem_mnt' is ERR_PTR, to
     avoid deferencing it.
     
     Link: https://lkml.kernel.org/r/20220904074647.GA64291@cloud-MacBookPro
     Fixes: 1507f51255c9f ("mm: introduce memfd_secret system call to create "secret" memory areas")
     Signed-off-by: Binyi Han <dantengknight@gmail.com>
     Reviewed-by: Andrew Morton <akpm@linux-foudation.org>
     Cc: Mike Rapoport <rppt@kernel.org>
     Cc: Ammar Faizi <ammarfaizi2@gnuweeb.org>
     Cc: Hagen Paul Pfeifer <hagen@jauu.net>
     Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
     Cc: <stable@vger.kernel.org>
     Signed-off-by: Andrew Morton <akpm@linux-foundation.org>


-- 
Thanks,

David / dhildenb