Re: [PATCH] Staging : android: Struct file_operations should be const

[Joe Perches]

On Mon, 2022-02-07 at 00:17 -0300, Leonardo Araujo wrote:
> From: "Leonardo Araujo" <leonardo.aa88@xxxxxxxxx>
> 
> WARNING: struct file_operations should normally be const

Always compile the files modified by a patch before you send it out.

[]
> diff --git 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;
>  

<apply patch>
$ make allyesconfig
$ make drivers/staging/android/ashmem.o
[...]
  CC      drivers/staging/android/ashmem.o
drivers/staging/android/ashmem.c: In function ‘ashmem_mmap’:
drivers/staging/android/ashmem.c:431:37: error: assignment of read-only variable ‘vmfile_fops’
  431 |                         vmfile_fops = *vmfile->f_op;
      |                                     ^
drivers/staging/android/ashmem.c:432:42: error: assignment of member ‘mmap’ in read-only object
  432 |                         vmfile_fops.mmap = ashmem_vmfile_mmap;
      |                                          ^
drivers/staging/android/ashmem.c:433:55: error: assignment of member ‘get_unmapped_area’ in read-only object
  433 |                         vmfile_fops.get_unmapped_area =
      |                                                       ^
make[3]: *** [scripts/Makefile.build:289: drivers/staging/android/ashmem.o] Error 1
make[2]: *** [scripts/Makefile.build:572: drivers/staging/android] Error 2
make[1]: *** [scripts/Makefile.build:572: drivers/staging] Error 2
make: *** [Makefile:1965: drivers] Error 2