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

From: Xie Yongji
Date: Mon May 17 2021 - 05:56:20 EST


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@xxxxxxxxxxxxx>
---
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 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);
--
2.11.0