Re: [PATCH v13 03/13] file: Export receive_fd() to modules

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Aug 31, 2021 at 06:36:24PM +0800, Xie Yongji wrote:
> Export receive_fd() so that some modules can use
> it to pass file descriptor between processes without
> missing any security stuffs.
> 
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> Acked-by: Jason Wang <jasowang@redhat.com>

This needs some acks from fs devels.
Viro?


> ---
>  fs/file.c            | 6 ++++++
>  include/linux/file.h | 7 +++----
>  2 files changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/file.c b/fs/file.c
> index 86dc9956af32..210e540672aa 100644
> --- a/fs/file.c
> +++ b/fs/file.c
> @@ -1134,6 +1134,12 @@ int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags)
>  	return new_fd;
>  }
>  
> +int receive_fd(struct file *file, unsigned int o_flags)
> +{
> +	return __receive_fd(file, NULL, o_flags);
> +}
> +EXPORT_SYMBOL_GPL(receive_fd);
> +
>  static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags)
>  {
>  	int err = -EBADF;
> diff --git a/include/linux/file.h b/include/linux/file.h
> index 2de2e4613d7b..51e830b4fe3a 100644
> --- a/include/linux/file.h
> +++ b/include/linux/file.h
> @@ -94,6 +94,9 @@ extern void fd_install(unsigned int fd, struct file *file);
>  
>  extern int __receive_fd(struct file *file, int __user *ufd,
>  			unsigned int o_flags);
> +
> +extern int receive_fd(struct file *file, unsigned int o_flags);
> +
>  static inline int receive_fd_user(struct file *file, int __user *ufd,
>  				  unsigned int o_flags)
>  {
> @@ -101,10 +104,6 @@ static inline int receive_fd_user(struct file *file, int __user *ufd,
>  		return -EFAULT;
>  	return __receive_fd(file, ufd, o_flags);
>  }
> -static inline int receive_fd(struct file *file, unsigned int o_flags)
> -{
> -	return __receive_fd(file, NULL, o_flags);
> -}
>  int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);
>  
>  extern void flush_delayed_fput(void);
> -- 
> 2.11.0