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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E131EC388F7 for ; Sat, 31 Oct 2020 11:50:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B8042065D for ; Sat, 31 Oct 2020 11:50:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604145055; bh=3pEmG3AOSznnPgnSo/shb2yrAfKCHH08OSL14uUoVkM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uoBsuI1g91+m5g3Oy5N6i7K61IQMddCjRO2PXrPkb9tt1wZdX2kWSo0YYYB90ZNBz MIMWBXePIEmnn0bK1ESlLHkWpBxGjgXjQ/kt1truEnakK60x+TzIOJrGV6bkHcHn+V nshuj1B2Q7hs25QA+qdlgHh06R7fwVanT0Rp4nEk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727476AbgJaLko (ORCPT ); Sat, 31 Oct 2020 07:40:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:39308 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727442AbgJaLkg (ORCPT ); Sat, 31 Oct 2020 07:40:36 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7B43220719; Sat, 31 Oct 2020 11:40:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604144436; bh=3pEmG3AOSznnPgnSo/shb2yrAfKCHH08OSL14uUoVkM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BbnDX//eOrx9eI8OxFV7HaHStzLOnfFvgC/gUp8lE2d+pfN9DAQZe/s/g8y90fv8d RVv4AYu21u1IU1YYDcN0GNvF0mJw//c/wpgBKMfzMktHfVwV5v4Kw4/6Kb2XzeJ9bb 1BmZAcgG3sMsQbVwt9Q7pA16snd+KMVYrixcL0HA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jens Axboe Subject: [PATCH 5.8 02/70] io_uring: dont run task work on an exiting task Date: Sat, 31 Oct 2020 12:35:34 +0100 Message-Id: <20201031113459.607784722@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201031113459.481803250@linuxfoundation.org> References: <20201031113459.481803250@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jens Axboe commit 6200b0ae4ea28a4bfd8eb434e33e6201b7a6a282 upstream. This isn't safe, and isn't needed either. We are guaranteed that any work we queue is on a live task (and will be run), or it goes to our backup io-wq threads if the task is exiting. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1762,6 +1762,12 @@ static int io_put_kbuf(struct io_kiocb * static inline bool io_run_task_work(void) { + /* + * Not safe to run on exiting task, and the task_work handling will + * not add work to such a task. + */ + if (unlikely(current->flags & PF_EXITING)) + return false; if (current->task_works) { __set_current_state(TASK_RUNNING); task_work_run(); @@ -7791,6 +7797,8 @@ static void io_uring_cancel_files(struct io_put_req(cancel_req); } + /* cancellations _may_ trigger task work */ + io_run_task_work(); schedule(); finish_wait(&ctx->inflight_wait, &wait); }