file: Export receive_fd() to modules

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>
Link: https://lore.kernel.org/r/20210831103634.33-4-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/fs/file.c b/fs/file.c
index 86dc995..210e540 100644 (file)
--- 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 2de2e46..51e830b 100644 (file)
--- 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);