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 813ACC6FD1D for ; Mon, 20 Mar 2023 08:04:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230284AbjCTIES (ORCPT ); Mon, 20 Mar 2023 04:04:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229762AbjCTIEP (ORCPT ); Mon, 20 Mar 2023 04:04:15 -0400 Received: from mout-p-102.mailbox.org (mout-p-102.mailbox.org [80.241.56.152]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6736A3C07; Mon, 20 Mar 2023 01:04:12 -0700 (PDT) Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:b231:465::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-102.mailbox.org (Postfix) with ESMTPS id 4Pg6h80ytJz9sx1; Mon, 20 Mar 2023 09:04:08 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=steffen.cc; s=MBO0001; t=1679299448; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=bTYHukQgUX4nzP26XOdQWPxkwbbqFAk7D0BpCeYCkSE=; b=kOMYnrqhCvK5YtABjE7vZcjQbdzAKuibr4CkPWDpinjcWO3NPh0elKeCpku3eglaXAY8LH atk5d3oeqiH/vEb20+PJGadSjC5o03eQ7hkAjrFeoae3v+T/qmZWgJ6jnbQAdexRTJt1dt DC36HewVs5jr9y0sMaJGkXOblANyMP02CqGzZBxc/s0e+H6gIeXtf9Dnukn9/uHeFPZxo4 lp91q8Bv1oGqvxFZZJjTvD/26C7Go6dUqXVUkoDPbfvu3vgAY5Se55Vf6u39saY3zAcCQB CGnNvOARSgd5vlykhmo1n/wxSVQohL+a5peLTQ2hQMl+fJgfG2JXWCFr9QxL7g== From: linux@steffen.cc To: "Luis Claudio R . Goncalves" , linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Steffen Dirkwinkel Subject: [PATCH v5.10-rt] kernel: fork: set wake_q_sleeper.next=NULL again in dup_task_struct Date: Mon, 20 Mar 2023 09:03:47 +0100 Message-Id: <20230320080347.32434-1-linux@steffen.cc> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4Pg6h80ytJz9sx1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steffen Dirkwinkel Without this we get system hangs within a couple of days. It's also reproducible in minutes with "stress-ng --exec 20". Example error in dmesg: INFO: task stress-ng:163916 blocked for more than 120 seconds. Not tainted 5.10.168-rt83 #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:stress-ng state:D stack: 0 pid:163916 ppid: 72833 flags:0x00004000 Call Trace: __schedule+0x2bd/0x940 preempt_schedule_lock+0x23/0x50 rt_spin_lock_slowlock_locked+0x117/0x2c0 rt_spin_lock_slowlock+0x51/0x80 rt_write_lock+0x1e/0x1c0 do_exit+0x3ac/0xb20 do_group_exit+0x39/0xb0 get_signal+0x145/0x960 ? wake_up_new_task+0x21f/0x3c0 arch_do_signal_or_restart+0xf1/0x830 ? __x64_sys_futex+0x146/0x1d0 exit_to_user_mode_prepare+0x116/0x1a0 syscall_exit_to_user_mode+0x28/0x190 entry_SYSCALL_64_after_hwframe+0x61/0xc6 RIP: 0033:0x7f738d9074a7 RSP: 002b:00007ffdafda3cb0 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00000000000000ca RCX: 00007f738d9074a7 RDX: 0000000000028051 RSI: 0000000000000000 RDI: 00007f738be949d0 RBP: 00007ffdafda3d88 R08: 0000000000000000 R09: 00007f738be94700 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000028051 R13: 00007f738be949d0 R14: 00007ffdafda51e0 R15: 00007f738be94700 Fixes: 1ba44dcf789d ("Merge tag 'v5.10.162' into v5.10-rt") Signed-off-by: Steffen Dirkwinkel --- kernel/fork.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/fork.c b/kernel/fork.c index c6e0d555fca9..0c4c20eb762c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -949,6 +949,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) tsk->splice_pipe = NULL; tsk->task_frag.page = NULL; tsk->wake_q.next = NULL; + tsk->wake_q_sleeper.next = NULL; tsk->pf_io_worker = NULL; account_kernel_stack(tsk, 1); -- 2.40.0