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

From: Greg Kroah-Hartman
Date: Fri Oct 02 2020 - 09:48:12 EST


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