Commit ab0b196c authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: fix overlapped memcpy in io_req_map_rw() 



When io_req_map_rw() is called from io_rw_prep_async(), it memcpy()
iorw->iter into itself. Even though it doesn't lead to an error, such a
memcpy()'s aliasing rules violation is considered to be a bad practise.

Inline io_req_map_rw() into io_rw_prep_async(). We don't really need any
remapping there, so it's much simpler than the generic implementation.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent afb87658

fs/io_uring.c

+4 −1
Original line number Diff line number Diff line
@@ -3071,7 +3071,10 @@ static inline int io_rw_prep_async(struct io_kiocb *req, int rw, 
	if (unlikely(ret < 0))

		return ret;



	io_req_map_rw(req, iov, iorw->fast_iov, &iorw->iter);

	iorw->bytes_done = 0;

	iorw->free_iovec = iov;

	if (iov)

		req->flags |= REQ_F_NEED_CLEANUP;

	return 0;

}