Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword Warning found by checkpatch.pl script.

[shaikh kamaluddin <shaikhkamal2012@gmail.com>]

On 3/14/2022 5:03 PM, Greg Kroah-Hartman wrote:
> On Mon, Mar 14, 2022 at 04:55:55PM +0530, shaikh kamaluddin wrote:
>> On 3/13/2022 3:13 AM, Pavel Skripkin wrote:
>>> Hi Shaikh,
>>>
>>> On 3/12/22 23:41, shaikh kamal wrote:
>>>> Signed-off-by: shaikh kamal <shaikhkamal2012@gmail.com>
>>>> ---
>>>>    drivers/staging/android/ashmem.c | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/staging/android/ashmem.c
>>>> b/drivers/staging/android/ashmem.c
>>>> index ddbde3f8430e..4c6b420fbf4d 100644
>>>> --- a/drivers/staging/android/ashmem.c
>>>> +++ b/drivers/staging/android/ashmem.c
>>>> @@ -377,7 +377,7 @@ ashmem_vmfile_get_unmapped_area(struct file
>>>> *file, unsigned long addr,
>>>>    static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
>>>>    {
>>>> -    static struct file_operations vmfile_fops;
>>>> +    static const struct file_operations vmfile_fops;
>>>>        struct ashmem_area *asma = file->private_data;
>>>>        int ret = 0;
>>>
>>> Are you sure this patch compiles? vmfile_fops is overrided few lines below
>>>
>>> odd checkpatch.pl warning...
>>>
>>>
>>>
>>>
>>> With regards,
>>> Pavel Skripkin
>>
>> Thank you,yes vmfile_fops is overrided in below code.
>> Building the kernel - make -j4,
>> drivers/staging/android/ashmem.c: In function ‘ashmem_mmap’:
>> drivers/staging/android/ashmem.c:431:16: error: assignment of read-only
>> variable ‘vmfile_fops’
>>      vmfile_fops = *vmfile->f_op;
>>                  ^
>> drivers/staging/android/ashmem.c:432:21: error: assignment of member ‘mmap’
>> in read-only object
>>      vmfile_fops.mmap = ashmem_vmfile_mmap;
>>                       ^
>> drivers/staging/android/ashmem.c:433:34: error: assignment of member
>> ‘get_unmapped_area’ in read-only object
>>      vmfile_fops.get_unmapped_area =
>>                                    ^
>> scripts/Makefile.build:288: recipe for target
>> 'drivers/staging/android/ashmem.o' failed
>> make[3]: *** [drivers/staging/android/ashmem.o] Error 1
>> scripts/Makefile.build:550: recipe for target 'drivers/staging/android'
>> failed
>> make[2]: *** [drivers/staging/android] Error 2
>> scripts/Makefile.build:550: recipe for target 'drivers/staging' failed
>> make[1]: *** [drivers/staging] Error 2
>> Makefile:1831: recipe for target 'drivers' failed
> 
> As always, it is expected that when you submit a change to the kernel,
> at the very least you have test-built it to ensure that it does not
> break the build.  Please remember to do this next time.
> 
> thanks,
> 
> greg k-h


Thank you, I will do that.

Regards,
Shaikh Kamaluddin