diff mbox series

[v7,02/12] file: Export receive_fd() to modules

Message ID 20210517095513.850-3-xieyongji@bytedance.com (mailing list archive)
State New
Headers show
Series Introduce VDUSE - vDPA Device in Userspace | expand

Commit Message

Xie Yongji May 17, 2021, 9:55 a.m. UTC
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>
---
 fs/file.c            | 6 ++++++
 include/linux/file.h | 7 +++----
 2 files changed, 9 insertions(+), 4 deletions(-)

Comments

Al Viro May 20, 2021, 6:18 a.m. UTC | #1
On Mon, May 17, 2021 at 05:55:03PM +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.

Which tree is that against?  Because in mainline this won't even build, let
alone work.

> --- a/fs/file.c
> +++ b/fs/file.c
> @@ -1135,6 +1135,12 @@ int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flag
>  	return new_fd;
>  }
>  
> +int receive_fd(struct file *file, unsigned int o_flags)
> +{
> +	return __receive_fd(-1, file, NULL, o_flags);
> +}
> +EXPORT_SYMBOL_GPL(receive_fd);

fs/file.c:1097:int __receive_fd(struct file *file, int __user *ufd, unsigned int o_flags)
Xie Yongji May 20, 2021, 6:32 a.m. UTC | #2
On Thu, May 20, 2021 at 2:18 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Mon, May 17, 2021 at 05:55:03PM +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.
>
> Which tree is that against?  Because in mainline this won't even build, let
> alone work.
>

Oh, sorry for that. Now I'm based on vhost.git tree. But looks like I
miss Christoph's commit
42eb0d54c08 ("fs: split receive_fd_replace from __receive_fd"). Will
rebase on it in v8.

Thanks,
Yongji
diff mbox series

Patch

diff --git a/fs/file.c b/fs/file.c
index f633348029a5..ef4da2eaf25b 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -1135,6 +1135,12 @@  int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flag
 	return new_fd;
 }
 
+int receive_fd(struct file *file, unsigned int o_flags)
+{
+	return __receive_fd(-1, 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 225982792fa2..4667f9567d3e 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(int 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(-1, file, ufd, o_flags);
 }
-static inline int receive_fd(struct file *file, unsigned int o_flags)
-{
-	return __receive_fd(-1, file, NULL, o_flags);
-}
 static inline int receive_fd_replace(int fd, struct file *file, unsigned int o_flags)
 {
 	return __receive_fd(fd, file, NULL, o_flags);