From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55606C433FE for ; Mon, 21 Nov 2022 11:52:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229642AbiKULwN (ORCPT ); Mon, 21 Nov 2022 06:52:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231448AbiKULwE (ORCPT ); Mon, 21 Nov 2022 06:52:04 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B654829375 for ; Mon, 21 Nov 2022 03:52:02 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 750ADB80ED0 for ; Mon, 21 Nov 2022 11:52:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88397C433D6; Mon, 21 Nov 2022 11:51:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669031520; bh=cl09z0IgKthlEkWpns64M10YDhVp3HThA/Xlmk9gG1w=; h=Subject:To:Cc:From:Date:From; b=I5rhl2ehBrYPrzRGiTnQraPw2kJwJw3oR6bRrsMJriGc/v5I2qOXiDGyQ/B9+PF3t nF10bytHG2TLPtzCVG2PmJfrXHNpkiv6ALchx/3IQ1YJEGXkNNTJTFe/xUQ/LLqgAT RvxnsQF5TbjMqEXD/qTUsRw1dzxc0jMhUn8oQf0M= Subject: FAILED: patch "[PATCH] io_uring: disallow self-propelled ring polling" failed to apply to 5.15-stable tree To: asml.silence@gmail.com, axboe@kernel.dk Cc: From: Date: Mon, 21 Nov 2022 12:51:56 +0100 Message-ID: <166903151616523@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . Possible dependencies: 7fdbc5f014c3 ("io_uring: disallow self-propelled ring polling") 2ba69707d915 ("io_uring: clean up io_poll_check_events return values") d245bca6375b ("io_uring: don't expose io_fill_cqe_aux()") f3b44f92e59a ("io_uring: move read/write related opcodes to its own file") c98817e6cd44 ("io_uring: move remaining file table manipulation to filetable.c") 735729844819 ("io_uring: move rsrc related data, core, and commands") 3b77495a9723 ("io_uring: split provided buffers handling into its own file") 7aaff708a768 ("io_uring: move cancelation into its own file") 329061d3e2f9 ("io_uring: move poll handling into its own file") cfd22e6b3319 ("io_uring: add opcode name to io_op_defs") 92ac8beaea1f ("io_uring: include and forward-declaration sanitation") c9f06aa7de15 ("io_uring: move io_uring_task (tctx) helpers into its own file") a4ad4f748ea9 ("io_uring: move fdinfo helpers to its own file") e5550a1447bf ("io_uring: use io_is_uring_fops() consistently") 17437f311490 ("io_uring: move SQPOLL related handling into its own file") 59915143e89f ("io_uring: move timeout opcodes and handling into its own file") e418bbc97bff ("io_uring: move our reference counting into a header") 36404b09aa60 ("io_uring: move msg_ring into its own file") f9ead18c1058 ("io_uring: split network related opcodes into its own file") e0da14def1ee ("io_uring: move statx handling to its own file") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 7fdbc5f014c3f71bc44673a2d6c5bb2d12d45f25 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Fri, 18 Nov 2022 15:41:41 +0000 Subject: [PATCH] io_uring: disallow self-propelled ring polling When we post a CQE we wake all ring pollers as it normally should be. However, if a CQE was generated by a multishot poll request targeting its own ring, it'll wake that request up, which will make it to post a new CQE, which will wake the request and so on until it exhausts all CQ entries. Don't allow multishot polling io_uring files but downgrade them to oneshots, which was always stated as a correct behaviour that the userspace should check for. Cc: stable@vger.kernel.org Fixes: aa43477b04025 ("io_uring: poll rework") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/3124038c0e7474d427538c2d915335ec28c92d21.1668785722.git.asml.silence@gmail.com Signed-off-by: Jens Axboe diff --git a/io_uring/poll.c b/io_uring/poll.c index c34019b18211..055632e9092a 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -246,6 +246,8 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) continue; if (req->apoll_events & EPOLLONESHOT) return IOU_POLL_DONE; + if (io_is_uring_fops(req->file)) + return IOU_POLL_DONE; /* multishot, just fill a CQE and proceed */ if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {