[PATCH RFC POC 39/50] seccomp: stop putting the listener descriptor back on failure

[Christian Brauner]

Rely on the fd exit path machinery.

Signed-off-by: Christian Brauner (Amutable) <brauner at kernel.org>
---
 kernel/seccomp.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 86cf4460d69e..dc275ab1e031 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1957,7 +1957,7 @@ static long seccomp_set_mode_filter(unsigned int flags,
 	const unsigned long seccomp_mode = SECCOMP_MODE_FILTER;
 	struct seccomp_filter *prepared = NULL;
 	long ret = -EINVAL;
-	int listener = -1;
+	const struct fd_slot *listener = NULL;
 	struct file *listener_f = NULL;
 
 	/* Validate flags. */
@@ -1990,15 +1990,14 @@ static long seccomp_set_mode_filter(unsigned int flags,
 		return PTR_ERR(prepared);
 
 	if (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) {
-		listener = get_unused_fd_flags(O_CLOEXEC);
-		if (listener < 0) {
-			ret = listener;
+		listener = fd_prepare(O_CLOEXEC);
+		if (IS_ERR(listener)) {
+			ret = PTR_ERR(listener);
 			goto out_free;
 		}
 
 		listener_f = init_listener(prepared);
 		if (IS_ERR(listener_f)) {
-			put_unused_fd(listener);
 			ret = PTR_ERR(listener_f);
 			goto out_free;
 		}
@@ -2038,11 +2037,9 @@ static long seccomp_set_mode_filter(unsigned int flags,
 		if (ret) {
 			listener_f->private_data = NULL;
 			fput(listener_f);
-			put_unused_fd(listener);
 			seccomp_notify_detach(prepared);
 		} else {
-			fd_install(listener, listener_f);
-			ret = listener;
+			ret = fd_stage(listener, listener_f);
 		}
 	}
 out_free:

-- 
2.53.0