2022-09-20 01:49:30

by Xiu Jianfeng

Subject: [PATCH] mm/secretmem: remove reduntant return value

The return value @ret is always 0, so remove it and return 0 directly.

Signed-off-by: Xiu Jianfeng <[email protected]>
---
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))
@@ -290,6 +288,6 @@ static int __init secretmem_init(void)
/* prevent secretmem mappings from ever getting PROT_EXEC */
secretmem_mnt->mnt_flags |= MNT_NOEXEC;

- return ret;
+ return 0;
}
fs_initcall(secretmem_init);
--
2.17.1

2022-09-20 12:53:44

by David Hildenbrand

Subject: Re: [PATCH] mm/secretmem: remove reduntant return value

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 <[email protected]>
> ---
> 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);

--
Thanks,

David / dhildenb

2022-09-20 13:30:52

by Xiu Jianfeng

Subject: Re: [PATCH] mm/secretmem: remove reduntant return value

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 <[email protected]>
>> ---
>>   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]:)

2022-09-20 13:34:51

by David Hildenbrand

Subject: Re: [PATCH] mm/secretmem: remove reduntant return value

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 <[email protected]>
>>> ---
>>>   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 <[email protected]>
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 <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Ammar Faizi <[email protected]>
Cc: Hagen Paul Pfeifer <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>


--
Thanks,

David / dhildenb