Re: [PATCH v1] binderfs: remove separate device_initcall()

[Todd Kjos <tkjos@google.com>]

On Wed, Jan 30, 2019 at 4:25 PM Christian Brauner <christian@brauner.io> wrote:
>
> binderfs should not have a separate device_initcall(). When a kernel is
> compiled with CONFIG_ANDROID_BINDERFS register the filesystem alongside
> CONFIG_ANDROID_IPC. This use-case is especially sensible when users specify
> CONFIG_ANDROID_IPC=y, CONFIG_ANDROID_BINDERFS=y and
> ANDROID_BINDER_DEVICES="".
> When CONFIG_ANDROID_BINDERFS=n then this always succeeds so there's no
> regression potential for legacy workloads.
>
> Signed-off-by: Christian Brauner <christian@brauner.io>

Acked-by: Todd Kjos <tkjos@google.com>

>
> ---
> /* Changelog */
> - ensure that device_name is set to NULL so kfree() doesn't freak out
> ---
>  drivers/android/binder.c          | 7 ++++++-
>  drivers/android/binder_internal.h | 9 +++++++++
>  drivers/android/binderfs.c        | 4 +---
>  3 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 57cf259de600..4d2b2ad1ee0e 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -5854,9 +5854,10 @@ static int __init init_binder_device(const char *name)
>  static int __init binder_init(void)
>  {
>         int ret;
> -       char *device_name, *device_names, *device_tmp;
> +       char *device_name, *device_tmp;
>         struct binder_device *device;
>         struct hlist_node *tmp;
> +       char *device_names = NULL;
>
>         ret = binder_alloc_shrinker_init();
>         if (ret)
> @@ -5917,6 +5918,10 @@ static int __init binder_init(void)
>                 }
>         }
>
> +       ret = init_binderfs();
> +       if (ret)
> +               goto err_init_binder_device_failed;
> +
>         return ret;
>
>  err_init_binder_device_failed:
> diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
> index 7fb97f503ef2..045b3e42d98b 100644
> --- a/drivers/android/binder_internal.h
> +++ b/drivers/android/binder_internal.h
> @@ -46,4 +46,13 @@ static inline bool is_binderfs_device(const struct inode *inode)
>  }
>  #endif
>
> +#ifdef CONFIG_ANDROID_BINDERFS
> +extern int __init init_binderfs(void);
> +#else
> +static inline int __init init_binderfs(void)
> +{
> +       return 0;
> +}
> +#endif
> +
>  #endif /* _LINUX_BINDER_INTERNAL_H */
> diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
> index 7a550104a722..e773f45d19d9 100644
> --- a/drivers/android/binderfs.c
> +++ b/drivers/android/binderfs.c
> @@ -550,7 +550,7 @@ static struct file_system_type binder_fs_type = {
>         .fs_flags       = FS_USERNS_MOUNT,
>  };
>
> -static int __init init_binderfs(void)
> +int __init init_binderfs(void)
>  {
>         int ret;
>
> @@ -568,5 +568,3 @@ static int __init init_binderfs(void)
>
>         return ret;
>  }
> -
> -device_initcall(init_binderfs);
> --
> 2.20.1
>