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Message-ID: <bf27518d-4990-8b0e-c6ea-26a658ce2e54@gmail.com>
Date:   Mon, 14 Mar 2022 16:55:55 +0530
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Subject: Re: [PATCH] staging: android: ashmem: Declared file operation with
 const keyword Warning found by checkpatch.pl script.
Content-Language: en-US
To:     Pavel Skripkin <paskripkin@gmail.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        =?UTF-8?Q?Arve_Hj=c3=b8nnev=c3=a5g?= <arve@android.com>,
        Todd Kjos <tkjos@android.com>,
        Martijn Coenen <maco@android.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Christian Brauner <brauner@kernel.org>,
        Hridya Valsaraju <hridya@google.com>,
        Suren Baghdasaryan <surenb@google.com>,
        linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev
References: <20220312204128.3942-1-shaikhkamal2012@gmail.com>
 <303ed0c8-8e2c-51a4-a4da-be973a25cdec@gmail.com>
From:   shaikh kamaluddin <shaikhkamal2012@gmail.com>
In-Reply-To: <303ed0c8-8e2c-51a4-a4da-be973a25cdec@gmail.com>
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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


Thanks & Regards,
Shaikh Kamaluddin