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

Xie Yongji
2021-08-31T10:39:10Z

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>
---
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