[PATCH RFC 4/5] file: stop exposing receive_fd_user()

From: Christian Brauner <brauner@kernel.org>
To: linux-fsdevel@vger.kernel.org
Cc: Jan Kara <jack@suse.com>, Jens Axboe <axboe@kernel.dk>,
	 Carlos Llamas <cmllamas@google.com>,
	 Alexander Viro <viro@zeniv.linux.org.uk>,
	 Linus Torvalds <torvalds@linux-foundation.org>,
	 Christian Brauner <brauner@kernel.org>
Subject: [PATCH RFC 4/5] file: stop exposing receive_fd_user()
Date: Thu, 30 Nov 2023 13:49:10 +0100	[thread overview]
Message-ID: <20231130-vfs-files-fixes-v1-4-e73ca6f4ea83@kernel.org> (raw)
In-Reply-To: <20231130-vfs-files-fixes-v1-0-e73ca6f4ea83@kernel.org>

Not every subsystem needs to have their own specialized helper.
Just us the __receive_fd() helper.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 include/linux/file.h | 7 -------
 include/net/scm.h    | 9 +++++++++
 net/compat.c         | 2 +-
 net/core/scm.c       | 2 +-
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/include/linux/file.h b/include/linux/file.h
index 6e9099d29343..c0d5219c2852 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -101,13 +101,6 @@ extern int __receive_fd(struct file *file, int __user *ufd,
 
 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)
-{
-	if (ufd == NULL)
-		return -EFAULT;
-	return __receive_fd(file, ufd, o_flags);
-}
 int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);
 
 extern void flush_delayed_fput(void);
diff --git a/include/net/scm.h b/include/net/scm.h
index e8c76b4be2fe..8aae2468bae0 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -5,6 +5,7 @@
 #include <linux/limits.h>
 #include <linux/net.h>
 #include <linux/cred.h>
+#include <linux/file.h>
 #include <linux/security.h>
 #include <linux/pid.h>
 #include <linux/nsproxy.h>
@@ -208,5 +209,13 @@ static inline void scm_recv_unix(struct socket *sock, struct msghdr *msg,
 	scm_destroy_cred(scm);
 }
 
+static inline int scm_recv_one_fd(struct file *f, int __user *ufd,
+				  unsigned int flags)
+{
+	if (!ufd)
+		return -EFAULT;
+	return __receive_fd(f, ufd, flags);
+}
+
 #endif /* __LINUX_NET_SCM_H */
 
diff --git a/net/compat.c b/net/compat.c
index 6564720f32b7..485db8ee9b28 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -297,7 +297,7 @@ void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm)
 	int err = 0, i;
 
 	for (i = 0; i < fdmax; i++) {
-		err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
+		err = scm_recv_one_fd(scm->fp->fp[i], cmsg_data + i, o_flags);
 		if (err < 0)
 			break;
 	}
diff --git a/net/core/scm.c b/net/core/scm.c
index 880027ecf516..eec78e312550 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -319,7 +319,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 	}
 
 	for (i = 0; i < fdmax; i++) {
-		err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
+		err = scm_recv_one_fd(scm->fp->fp[i], cmsg_data + i, o_flags);
 		if (err < 0)
 			break;
 	}

-- 
2.42.0

