Commit f0a4e62b authored Feb 07, 2022 by Nathan Chancellor Committed by Jens Axboe Mar 10, 2022

io_uring: Fix use of uninitialized ret in io_eventfd_register()

Clang warns:

  fs/io_uring.c:9396:9: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
          return ret;
                 ^~~
  fs/io_uring.c:9373:13: note: initialize the variable 'ret' to silence this warning
          int fd, ret;
                     ^
                      = 0
  1 warning generated.

Just return 0 directly and reduce the scope of ret to the if statement,
as that is the only place that it is used, which is how the function was
before the fixes commit.

Fixes: 1a75fac9a0f9 ("io_uring: avoid ring quiesce while registering/unregistering eventfd")
Link: https://github.com/ClangBuiltLinux/linux/issues/1579


Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220207162410.1013466-1-nathan@kernel.org


Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 8bb649ee

fs/io_uring.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -9378,7 +9378,7 @@ static int io_eventfd_register(struct io_ring_ctx ctx, void __user arg,
		{
		struct io_ev_fd *ev_fd;
		__s32 __user *fds = arg;
		int fd, ret;
		int fd;

		ev_fd = rcu_dereference_protected(ctx->io_ev_fd,
		lockdep_is_held(&ctx->uring_lock));
		@@ -9394,14 +9394,14 @@ static int io_eventfd_register(struct io_ring_ctx ctx, void __user arg,

		ev_fd->cq_ev_fd = eventfd_ctx_fdget(fd);
		if (IS_ERR(ev_fd->cq_ev_fd)) {
		ret = PTR_ERR(ev_fd->cq_ev_fd);
		int ret = PTR_ERR(ev_fd->cq_ev_fd);
		kfree(ev_fd);
		return ret;
		}
		ev_fd->eventfd_async = eventfd_async;

		rcu_assign_pointer(ctx->io_ev_fd, ev_fd);
		return ret;
		return 0;
		}

		static void io_eventfd_put(struct rcu_head *rcu)