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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 98868ECDE4C for ; Thu, 8 Nov 2018 20:35:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CFAC20840 for ; Thu, 8 Nov 2018 20:35:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6CFAC20840 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727558AbeKIGNB (ORCPT ); Fri, 9 Nov 2018 01:13:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:7622 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727519AbeKIGNB (ORCPT ); Fri, 9 Nov 2018 01:13:01 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1509F307D85A; Thu, 8 Nov 2018 20:35:52 +0000 (UTC) Received: from llong.com (dhcp-17-55.bos.redhat.com [10.18.17.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id BE648101F97D; Thu, 8 Nov 2018 20:35:50 +0000 (UTC) From: Waiman Long To: Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner Cc: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Petr Mladek , Sergey Senozhatsky , Andrey Ryabinin , Tejun Heo , Andrew Morton , Waiman Long Subject: [RFC PATCH 07/12] locking/lockdep: Add support for nested terminal locks Date: Thu, 8 Nov 2018 15:34:23 -0500 Message-Id: <1541709268-3766-8-git-send-email-longman@redhat.com> In-Reply-To: <1541709268-3766-1-git-send-email-longman@redhat.com> References: <1541709268-3766-1-git-send-email-longman@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Thu, 08 Nov 2018 20:35:52 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are use cases where we want to allow 2-level nesting of one terminal lock underneath another one. So the terminal lock type is now extended to support a new nested terminal lock where it can allow the acquisition of another regular terminal lock underneath it. Signed-off-by: Waiman Long --- include/linux/lockdep.h | 9 ++++++++- kernel/locking/lockdep.c | 15 +++++++++++++-- kernel/locking/lockdep_internals.h | 2 +- 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index c5ff8c5..ed4d177 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -147,12 +147,16 @@ struct lock_class_stats { * 1) LOCKDEP_FLAG_NOVALIDATE: No full validation, just simple checks. * 2) LOCKDEP_FLAG_TERMINAL: This is a terminal lock where lock/unlock on * another lock within its critical section is not allowed. + * 3) LOCKDEP_FLAG_TERMINAL_NESTED: This is a terminal lock that allows + * one more regular terminal lock to be nested underneath it. */ #define LOCKDEP_FLAG_NOVALIDATE (1 << 0) #define LOCKDEP_FLAG_TERMINAL (1 << 1) +#define LOCKDEP_FLAG_TERMINAL_NESTED (1 << 2) #define LOCKDEP_NOCHECK_FLAGS (LOCKDEP_FLAG_NOVALIDATE |\ - LOCKDEP_FLAG_TERMINAL) + LOCKDEP_FLAG_TERMINAL |\ + LOCKDEP_FLAG_TERMINAL_NESTED) /* * Map the lock object (the lock instance) to the lock-class object. @@ -314,6 +318,8 @@ extern void lockdep_init_map(struct lockdep_map *lock, const char *name, do { (lock)->dep_map.flags |= LOCKDEP_FLAG_NOVALIDATE; } while (0) #define lockdep_set_terminal_class(lock) \ do { (lock)->dep_map.flags |= LOCKDEP_FLAG_TERMINAL; } while (0) +#define lockdep_set_terminal_nested_class(lock) \ + do { (lock)->dep_map.flags |= LOCKDEP_FLAG_TERMINAL_NESTED; } while (0) /* * Compare locking classes @@ -431,6 +437,7 @@ static inline void lockdep_on(void) #define lockdep_set_novalidate_class(lock) do { } while (0) #define lockdep_set_terminal_class(lock) do { } while (0) +#define lockdep_set_terminal_nested_class(lock) do { } while (0) /* * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 02631a0..2b75613 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -3268,13 +3268,24 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, class_idx = class - lock_classes + 1; if (depth) { + int prev_type; + hlock = curr->held_locks + depth - 1; /* - * Warn if the previous lock is a terminal lock. + * Warn if the previous lock is a terminal lock or the + * previous lock is a nested terminal lock and the current + * one isn't a regular terminal lock. */ - if (DEBUG_LOCKS_WARN_ON(hlock_is_terminal(hlock))) + prev_type = hlock_is_terminal(hlock); + if (DEBUG_LOCKS_WARN_ON((prev_type == LOCKDEP_FLAG_TERMINAL) || + ((prev_type == LOCKDEP_FLAG_TERMINAL_NESTED) && + (flags_is_terminal(class->flags) != + LOCKDEP_FLAG_TERMINAL)))) { + pr_warn("Terminal lock error: prev lock = %s, curr lock = %s\n", + hlock->instance->name, class->name); return 0; + } if (hlock->class_idx == class_idx && nest_lock) { if (hlock->references) { diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index 271fba8..abe646a 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -215,5 +215,5 @@ static inline unsigned long debug_class_ops_read(struct lock_class *class) static inline unsigned int flags_is_terminal(unsigned int flags) { - return flags & LOCKDEP_FLAG_TERMINAL; + return flags & (LOCKDEP_FLAG_TERMINAL|LOCKDEP_FLAG_TERMINAL_NESTED); } -- 1.8.3.1