From patchwork Mon Mar 23 15:20:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 1260111 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linutronix.de Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48mJ466CRPz9sRY for ; Tue, 24 Mar 2020 02:20:54 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727239AbgCWPUs (ORCPT ); Mon, 23 Mar 2020 11:20:48 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:41746 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727127AbgCWPUs (ORCPT ); Mon, 23 Mar 2020 11:20:48 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1jGOsF-000148-59; Mon, 23 Mar 2020 16:20:19 +0100 Date: Mon, 23 Mar 2020 16:20:19 +0100 From: Sebastian Siewior To: Thomas Gleixner Cc: LKML , Peter Zijlstra , Ingo Molnar , Linus Torvalds , Joel Fernandes , Oleg Nesterov , Davidlohr Bueso , Davidlohr Bueso , Greg Kroah-Hartman , Logan Gunthorpe , Bjorn Helgaas , Kurt Schwemmer , linux-pci@vger.kernel.org, Felipe Balbi , linux-usb@vger.kernel.org, Kalle Valo , "David S. Miller" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, Darren Hart , Andy Shevchenko , platform-driver-x86@vger.kernel.org, Zhang Rui , "Rafael J. Wysocki" , linux-pm@vger.kernel.org, Len Brown , linux-acpi@vger.kernel.org, kbuild test robot , Nick Hu , Greentime Hu , Vincent Chen , Guo Ren , linux-csky@vger.kernel.org, Brian Cain , linux-hexagon@vger.kernel.org, Tony Luck , Fenghua Yu , linux-ia64@vger.kernel.org, Michal Simek , Michael Ellerman , Arnd Bergmann , Geoff Levand , linuxppc-dev@lists.ozlabs.org, "Paul E . McKenney" , Jonathan Corbet , Randy Dunlap Subject: [PATCH] completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() Message-ID: <20200323152019.4qjwluldohuh3by5@linutronix.de> References: <20200321112544.878032781@linutronix.de> <20200321113242.317954042@linutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200321113242.317954042@linutronix.de> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The warning was intended to spot complete_all() users from hardirq context on PREEMPT_RT. The warning as-is will also trigger in interrupt handlers, which are threaded on PREEMPT_RT, which was not intended. Use lockdep_assert_RT_in_threaded_ctx() which triggers in non-preemptive context on PREEMPT_RT. Suggested-by: Peter Zijlstra Reported-by: kernel test robot Signed-off-by: Sebastian Andrzej Siewior --- include/linux/lockdep.h | 15 +++++++++++++++ kernel/sched/completion.c | 2 +- 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 425b4ceb7cd07..206774ac69460 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -711,6 +711,21 @@ do { \ # define lockdep_assert_in_irq() do { } while (0) #endif +#ifdef CONFIG_PROVE_RAW_LOCK_NESTING + +# define lockdep_assert_RT_in_threaded_ctx() do { \ + WARN_ONCE(debug_locks && !current->lockdep_recursion && \ + current->hardirq_context && \ + !(current->hardirq_threaded || current->irq_config), \ + "Not in threaded context on PREEMPT_RT as expected\n"); \ +} while (0) + +#else + +# define lockdep_assert_RT_in_threaded_ctx() do { } while (0) + +#endif + #ifdef CONFIG_LOCKDEP void lockdep_rcu_suspicious(const char *file, const int line, const char *s); #else diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c index f15e96164ff1e..a778554f9dad7 100644 --- a/kernel/sched/completion.c +++ b/kernel/sched/completion.c @@ -58,7 +58,7 @@ void complete_all(struct completion *x) { unsigned long flags; - WARN_ON(irqs_disabled()); + lockdep_assert_RT_in_threaded_ctx(); raw_spin_lock_irqsave(&x->wait.lock, flags); x->done = UINT_MAX;