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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EB6D0C433DB for ; Mon, 1 Feb 2021 12:55:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD77B64EBA for ; Mon, 1 Feb 2021 12:55:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231796AbhBAMzW (ORCPT ); Mon, 1 Feb 2021 07:55:22 -0500 Received: from wforward5-smtp.messagingengine.com ([64.147.123.35]:52785 "EHLO wforward5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231703AbhBAMzK (ORCPT ); Mon, 1 Feb 2021 07:55:10 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailforward.west.internal (Postfix) with ESMTP id EBE5B60D; Mon, 1 Feb 2021 07:54:19 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Mon, 01 Feb 2021 07:54:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=6pFQqa Oz0CG2uuRKwDPtbqwhQYTRyYVJD5XeSQNyW/8=; b=UFN4/FhIiCRFriGs4nXION IyESGPW4q8pw1AM8JO35Q+3fIlJGYhCzEP2MvSp3njUyPluhx0w3pn1qeWqMYdKM CqtO1xMyFp3zN9F6gPjrW9oMLpBbThFKtd8phNDlxrEHNNUGmcLjhjfJZZT3/WDI pgAN/oy1uPfnp65RIq1wRZHwHl3JIf44lzmmj10RPN5FD/bGYJuutucvzojnV5h1 4YfXG+s6KXn40f4HgOHKdvOec9hRHUGBZNaeer0fXWF26YIeA6F5nDwcfRPxhlrm BPmVLELR+7gpWrUPZytKcH6knqVbJMjh3ev6YKqWg3Bt2OKr/DvlaEozamK422tg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrfeekgdeghecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertddttd flnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdhorhhg qeenucggtffrrghtthgvrhhnpeeiteevheeuvdfhtdfgvdeiieehheefleevveehjedute evueevledujeejgfetheenucfkphepkeefrdekiedrjeegrdeigeenucevlhhushhtvghr ufhiiigvpeefnecurfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhrohgrhhdrtg homh X-ME-Proxy: Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) by mail.messagingengine.com (Postfix) with ESMTPA id 0DF2124005D; Mon, 1 Feb 2021 07:54:18 -0500 (EST) Subject: FAILED: patch "[PATCH] io_uring: fix cancellation taking mutex while" failed to apply to 5.10-stable tree To: asml.silence@gmail.com, axboe@kernel.dk Cc: From: Date: Mon, 01 Feb 2021 13:54:17 +0100 Message-ID: <161218405715580@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 5.10-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 . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ca70f00bed6cb255b7a9b91aa18a2717c9217f70 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Tue, 26 Jan 2021 15:28:27 +0000 Subject: [PATCH] io_uring: fix cancellation taking mutex while TASK_UNINTERRUPTIBLE do not call blocking ops when !TASK_RUNNING; state=2 set at [<00000000ced9dbfc>] prepare_to_wait+0x1f4/0x3b0 kernel/sched/wait.c:262 WARNING: CPU: 1 PID: 19888 at kernel/sched/core.c:7853 __might_sleep+0xed/0x100 kernel/sched/core.c:7848 RIP: 0010:__might_sleep+0xed/0x100 kernel/sched/core.c:7848 Call Trace: __mutex_lock_common+0xc4/0x2ef0 kernel/locking/mutex.c:935 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 io_wq_submit_work+0x39a/0x720 fs/io_uring.c:6411 io_run_cancel fs/io-wq.c:856 [inline] io_wqe_cancel_pending_work fs/io-wq.c:990 [inline] io_wq_cancel_cb+0x614/0xcb0 fs/io-wq.c:1027 io_uring_cancel_files fs/io_uring.c:8874 [inline] io_uring_cancel_task_requests fs/io_uring.c:8952 [inline] __io_uring_files_cancel+0x115d/0x19e0 fs/io_uring.c:9038 io_uring_files_cancel include/linux/io_uring.h:51 [inline] do_exit+0x2e6/0x2490 kernel/exit.c:780 do_group_exit+0x168/0x2d0 kernel/exit.c:922 get_signal+0x16b5/0x2030 kernel/signal.c:2770 arch_do_signal_or_restart+0x8e/0x6a0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0xac/0x1e0 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x48/0x190 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Rewrite io_uring_cancel_files() to mimic __io_uring_task_cancel()'s counting scheme, so it does all the heavy work before setting TASK_UNINTERRUPTIBLE. Cc: stable@vger.kernel.org # 5.9+ Reported-by: syzbot+f655445043a26a7cfab8@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov [axboe: fix inverted task check] Signed-off-by: Jens Axboe diff --git a/fs/io_uring.c b/fs/io_uring.c index 09aada153a71..bb0270eeb8cb 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8873,30 +8873,31 @@ static void io_cancel_defer_files(struct io_ring_ctx *ctx, } } +static int io_uring_count_inflight(struct io_ring_ctx *ctx, + struct task_struct *task, + struct files_struct *files) +{ + struct io_kiocb *req; + int cnt = 0; + + spin_lock_irq(&ctx->inflight_lock); + list_for_each_entry(req, &ctx->inflight_list, inflight_entry) + cnt += io_match_task(req, task, files); + spin_unlock_irq(&ctx->inflight_lock); + return cnt; +} + static void io_uring_cancel_files(struct io_ring_ctx *ctx, struct task_struct *task, struct files_struct *files) { while (!list_empty_careful(&ctx->inflight_list)) { struct io_task_cancel cancel = { .task = task, .files = files }; - struct io_kiocb *req; DEFINE_WAIT(wait); - bool found = false; - - spin_lock_irq(&ctx->inflight_lock); - list_for_each_entry(req, &ctx->inflight_list, inflight_entry) { - if (!io_match_task(req, task, files)) - continue; - found = true; - break; - } - if (found) - prepare_to_wait(&task->io_uring->wait, &wait, - TASK_UNINTERRUPTIBLE); - spin_unlock_irq(&ctx->inflight_lock); + int inflight; - /* We need to keep going until we don't find a matching req */ - if (!found) + inflight = io_uring_count_inflight(ctx, task, files); + if (!inflight) break; io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true); @@ -8905,7 +8906,11 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, io_cqring_overflow_flush(ctx, true, task, files); /* cancellations _may_ trigger task work */ io_run_task_work(); - schedule(); + + prepare_to_wait(&task->io_uring->wait, &wait, + TASK_UNINTERRUPTIBLE); + if (inflight == io_uring_count_inflight(ctx, task, files)) + schedule(); finish_wait(&task->io_uring->wait, &wait); } }