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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 1551FC43381 for ; Thu, 28 Feb 2019 07:06:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0AA321850 for ; Thu, 28 Feb 2019 07:06:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731390AbfB1HG2 (ORCPT ); Thu, 28 Feb 2019 02:06:28 -0500 Received: from terminus.zytor.com ([198.137.202.136]:41481 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731129AbfB1HG2 (ORCPT ); Thu, 28 Feb 2019 02:06:28 -0500 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x1S75xOu2938362 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 27 Feb 2019 23:05:59 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x1S75xok2938357; Wed, 27 Feb 2019 23:05:59 -0800 Date: Wed, 27 Feb 2019 23:05:59 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Bart Van Assche Message-ID: Cc: mingo@kernel.org, johannes@sipsolutions.net, peterz@infradead.org, torvalds@linux-foundation.org, longman@redhat.com, tglx@linutronix.de, bvanassche@acm.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, hpa@zytor.com, paulmck@linux.vnet.ibm.com, will.deacon@arm.com Reply-To: torvalds@linux-foundation.org, peterz@infradead.org, johannes@sipsolutions.net, mingo@kernel.org, longman@redhat.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, bvanassche@acm.org, tglx@linutronix.de, will.deacon@arm.com, paulmck@linux.vnet.ibm.com, hpa@zytor.com In-Reply-To: <20190214230058.196511-7-bvanassche@acm.org> References: <20190214230058.196511-7-bvanassche@acm.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] locking/lockdep: Make zap_class() remove all matching lock order entries Git-Commit-ID: 86cffb80a525f7b8f969c8c79669d383e02f17d1 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 86cffb80a525f7b8f969c8c79669d383e02f17d1 Gitweb: https://git.kernel.org/tip/86cffb80a525f7b8f969c8c79669d383e02f17d1 Author: Bart Van Assche AuthorDate: Thu, 14 Feb 2019 15:00:41 -0800 Committer: Ingo Molnar CommitDate: Thu, 28 Feb 2019 07:55:40 +0100 locking/lockdep: Make zap_class() remove all matching lock order entries Make sure that all lock order entries that refer to a class are removed from the list_entries[] array when a kernel module is unloaded. Signed-off-by: Bart Van Assche Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Johannes Berg Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Waiman Long Cc: Will Deacon Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-7-bvanassche@acm.org Signed-off-by: Ingo Molnar --- include/linux/lockdep.h | 1 + kernel/locking/lockdep.c | 19 +++++++++++++------ 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 0c38bade84b7..b5e6bfe0ae4a 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -178,6 +178,7 @@ static inline void lockdep_copy_map(struct lockdep_map *to, struct lock_list { struct list_head entry; struct lock_class *class; + struct lock_class *links_to; struct stack_trace trace; int distance; diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 21d84510e28f..28fbeb2a10cc 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -859,7 +859,8 @@ static struct lock_list *alloc_list_entry(void) /* * Add a new dependency to the head of the list: */ -static int add_lock_to_list(struct lock_class *this, struct list_head *head, +static int add_lock_to_list(struct lock_class *this, + struct lock_class *links_to, struct list_head *head, unsigned long ip, int distance, struct stack_trace *trace) { @@ -873,6 +874,7 @@ static int add_lock_to_list(struct lock_class *this, struct list_head *head, return 0; entry->class = this; + entry->links_to = links_to; entry->distance = distance; entry->trace = *trace; /* @@ -1907,14 +1909,14 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * Ok, all validations passed, add the new lock * to the previous lock's dependency list: */ - ret = add_lock_to_list(hlock_class(next), + ret = add_lock_to_list(hlock_class(next), hlock_class(prev), &hlock_class(prev)->locks_after, next->acquire_ip, distance, trace); if (!ret) return 0; - ret = add_lock_to_list(hlock_class(prev), + ret = add_lock_to_list(hlock_class(prev), hlock_class(next), &hlock_class(next)->locks_before, next->acquire_ip, distance, trace); if (!ret) @@ -4107,15 +4109,20 @@ void lockdep_reset(void) */ static void zap_class(struct lock_class *class) { + struct lock_list *entry; int i; /* * Remove all dependencies this lock is * involved in: */ - for (i = 0; i < nr_list_entries; i++) { - if (list_entries[i].class == class) - list_del_rcu(&list_entries[i].entry); + for (i = 0, entry = list_entries; i < nr_list_entries; i++, entry++) { + if (entry->class != class && entry->links_to != class) + continue; + list_del_rcu(&entry->entry); + /* Clear .class and .links_to to avoid double removal. */ + WRITE_ONCE(entry->class, NULL); + WRITE_ONCE(entry->links_to, NULL); } /* * Unhash the class and remove it from the all_lock_classes list: