Re: [PATCH v3 -next] binder: simplify the return expression of binder_mmap

[Greg Kroah-Hartman]

On Tue, Sep 29, 2020 at 09:52:16AM +0800, Liu Shixin wrote:
> Simplify the return expression.
> 
> Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
> ---
> v3: Add the change description.
> v2: Get rid of the "ret" and "failure string" variables.
> v1: Simplify the return expression.
> ---
>  drivers/android/binder.c | 18 ++++--------------
>  1 file changed, 4 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 37a505c41dec..49c0700816a5 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -5180,9 +5180,7 @@ static const struct vm_operations_struct binder_vm_ops = {
>  
>  static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
>  {
> -	int ret;
>  	struct binder_proc *proc = filp->private_data;
> -	const char *failure_string;
>  
>  	if (proc->tsk != current->group_leader)
>  		return -EINVAL;
> @@ -5194,9 +5192,9 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
>  		     (unsigned long)pgprot_val(vma->vm_page_prot));
>  
>  	if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
> -		ret = -EPERM;
> -		failure_string = "bad vm_flags";
> -		goto err_bad_arg;
> +		pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
> +		       proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM);
> +		return -EPERM;
>  	}
>  	vma->vm_flags |= VM_DONTCOPY | VM_MIXEDMAP;
>  	vma->vm_flags &= ~VM_MAYWRITE;
> @@ -5204,15 +5202,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
>  	vma->vm_ops = &binder_vm_ops;
>  	vma->vm_private_data = proc;
>  
> -	ret = binder_alloc_mmap_handler(&proc->alloc, vma);
> -	if (ret)
> -		return ret;
> -	return 0;
> -
> -err_bad_arg:
> -	pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
> -	       proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
> -	return ret;
> +	return binder_alloc_mmap_handler(&proc->alloc, vma);
>  }
>  
>  static int binder_open(struct inode *nodp, struct file *filp)
> -- 
> 2.25.1

Todd and other Binder maintainers, what do you think of this?

thanks,

greg k-h