From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965876AbdGTXfG (ORCPT ); Thu, 20 Jul 2017 19:35:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:42296 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936260AbdGTXfF (ORCPT ); Thu, 20 Jul 2017 19:35:05 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B05FC22B67 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Thu, 20 Jul 2017 19:35:01 -0400 From: Steven Rostedt To: LKML Cc: Thomas Gleixner , QLogic-Storage-Upstream@qlogic.com, martin.petersen@oracle.com, James Bottomley Subject: [BUG] lockdep splat with cpu_hotplug_lock Message-ID: <20170720193501.4f09499f@gandalf.local.home> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org My tests triggered this splat on 4.13-rc1: Loading iSCSI transport class v2.0-870. QLogic NetXtreme II iSCSI Driver bnx2i v2.7.10.1 (Jul 16, 2014) iscsi: registered transport (bnx2i) ============================================ WARNING: possible recursive locking detected 4.13.0-rc1-test+ #2 Not tainted -------------------------------------------- swapper/0/1 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++++}, at: [] __cpuhp_setup_state+0x28/0x59 but task is already holding lock: (cpu_hotplug_lock.rw_sem){++++++}, at: [] bnx2i_mod_init+0x134/0x209 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(cpu_hotplug_lock.rw_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by swapper/0/1: #0: (cpu_hotplug_lock.rw_sem){++++++}, at: [] bnx2i_mod_init+0x134/0x209 stack backtrace: CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc1-test+ #2 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 Call Trace: dump_stack+0x68/0x92 __lock_acquire+0x84b/0xebb ? __lock_is_held+0x47/0x7a ? mark_held_locks+0x5e/0x74 ? _raw_spin_unlock_irqrestore+0x40/0x47 lock_acquire+0x108/0x19c ? lock_acquire+0x108/0x19c ? __cpuhp_setup_state+0x28/0x59 cpus_read_lock+0x2f/0x5f ? __cpuhp_setup_state+0x28/0x59 __cpuhp_setup_state+0x28/0x59 ? bnx2i_percpu_thread_create+0x79/0x79 bnx2i_mod_init+0x17a/0x209 ? iscsi_transport_init+0x1c1/0x1c1 ? set_debug_rodata+0x17/0x17 do_one_initcall+0x90/0x131 ? set_debug_rodata+0x17/0x17 kernel_init_freeable+0x1e5/0x26d ? rest_init+0xd8/0xd8 kernel_init+0xe/0xfa ret_from_fork+0x27/0x40 ahci 0000:00:1f.2: version 3.0 ahci 0000:00:1f.2: AHCI 0001.0300 32 slots 6 ports 6 Gbps 0x3 impl SATA mode ahci 0000:00:1f.2: flags: 64bit ncq led clo pio slum part ems apst scsi host0: ahci I'd let the powers that be figure it out. -- Steve