Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull 'struct fd' class updates from Al Viro:
 "The bulk of struct fd memory safety stuff

  Making sure that struct fd instances are destroyed in the same scope
  where they'd been created, getting rid of reassignments and passing
  them by reference, converting to CLASS(fd{,_pos,_raw}).

  We are getting very close to having the memory safety of that stuff
  trivial to verify"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  deal with the last remaing boolean uses of fd_file()
  css_set_fork(): switch to CLASS(fd_raw, ...)
  memcg_write_event_control(): switch to CLASS(fd)
  assorted variants of irqfd setup: convert to CLASS(fd)
  do_pollfd(): convert to CLASS(fd)
  convert do_select()
  convert vfs_dedupe_file_range().
  convert cifs_ioctl_copychunk()
  convert media_request_get_by_fd()
  convert spu_run(2)
  switch spufs_calls_{get,put}() to CLASS() use
  convert cachestat(2)
  convert do_preadv()/do_pwritev()
  fdget(), more trivial conversions
  fdget(), trivial conversions
  privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
  o2hb_region_dev_store(): avoid goto around fdget()/fdput()
  introduce "fd_pos" class, convert fdget_pos() users to it.
  fdget_raw() users: switch to CLASS(fd_raw)
  convert vmsplice() to CLASS(fd)
  ...

1 files changed, 11 insertions, 27 deletions

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 826d21c4486b..62433cb3d2c2 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -2259,25 +2259,22 @@ int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds,
 {
 	int error;
 	int full_check = 0;
-	struct fd f, tf;
 	struct eventpoll *ep;
 	struct epitem *epi;
 	struct eventpoll *tep = NULL;
 
-	error = -EBADF;
-	f = fdget(epfd);
-	if (!fd_file(f))
-		goto error_return;
+	CLASS(fd, f)(epfd);
+	if (fd_empty(f))
+		return -EBADF;
 
 	/* Get the "struct file *" for the target file */
-	tf = fdget(fd);
-	if (!fd_file(tf))
-		goto error_fput;
+	CLASS(fd, tf)(fd);
+	if (fd_empty(tf))
+		return -EBADF;
 
 	/* The target file descriptor must support poll */
-	error = -EPERM;
 	if (!file_can_poll(fd_file(tf)))
-		goto error_tgt_fput;
+		return -EPERM;
 
 	/* Check if EPOLLWAKEUP is allowed */
 	if (ep_op_has_event(op))
@@ -2396,12 +2393,6 @@ error_tgt_fput:
 		loop_check_gen++;
 		mutex_unlock(&epnested_mutex);
 	}
-
-	fdput(tf);
-error_fput:
-	fdput(f);
-error_return:
-
 	return error;
 }
 
@@ -2429,8 +2420,6 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
 static int do_epoll_wait(int epfd, struct epoll_event __user *events,
 			 int maxevents, struct timespec64 *to)
 {
-	int error;
-	struct fd f;
 	struct eventpoll *ep;
 
 	/* The maximum number of event must be greater than zero */
@@ -2442,17 +2431,16 @@ static int do_epoll_wait(int epfd, struct epoll_event __user *events,
 		return -EFAULT;
 
 	/* Get the "struct file *" for the eventpoll file */
-	f = fdget(epfd);
-	if (!fd_file(f))
+	CLASS(fd, f)(epfd);
+	if (fd_empty(f))
 		return -EBADF;
 
 	/*
 	 * We have to check that the file structure underneath the fd
 	 * the user passed to us _is_ an eventpoll file.
 	 */
-	error = -EINVAL;
 	if (!is_file_epoll(fd_file(f)))
-		goto error_fput;
+		return -EINVAL;
 
 	/*
 	 * At this point it is safe to assume that the "private_data" contains
@@ -2461,11 +2449,7 @@ static int do_epoll_wait(int epfd, struct epoll_event __user *events,
 	ep = fd_file(f)->private_data;
 
 	/* Time to fish for events ... */
-	error = ep_poll(ep, events, maxevents, to);
-
-error_fput:
-	fdput(f);
-	return error;
+	return ep_poll(ep, events, maxevents, to);
 }
 
 SYSCALL_DEFINE4(epoll_wait, int, epfd, struct epoll_event __user *, events,