From ab0b196ce5551a093388bb2ceace30df7891051c Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sun, 6 Sep 2020 00:45:47 +0300 Subject: [PATCH] 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: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index bc7028d9e6f9..ed7032bb76bf 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -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; }