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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 0365CC32750 for ; Fri, 2 Aug 2019 10:00:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D061F20665 for ; Fri, 2 Aug 2019 10:00:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564740020; bh=sjU39/06cAWp44DyUMSwwUya99C8wbkAQnuEq44IuLc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JNtksKUGpIGeCqUby5ThOElC2zUrhGKMc60G4u2YvJm6L3azXa5+IqNWDRwH4bTU3 TGO8q2EwsV/tLs35nuGIg6t6W38JXbnlZsZYQN3uGHvCOEnG9OubK1DA/GUNcDD+rA n1JdokZpuuEUHMbssLIMn6ZZFXj9SToLEq+Gtjr4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407051AbfHBKAT (ORCPT ); Fri, 2 Aug 2019 06:00:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:58526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406065AbfHBJwo (ORCPT ); Fri, 2 Aug 2019 05:52:44 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 802ED20880; Fri, 2 Aug 2019 09:52:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739564; bh=sjU39/06cAWp44DyUMSwwUya99C8wbkAQnuEq44IuLc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eY6wPkYup9bzX/ceEPQjirBE/GPKzS1EosiGw572J4gMrcILZr0Pmm7VfaRxazrF+ riD0A25TF3CCBf6HjCGbGFdSIwYOq53fa12C2t7oh6ZRyKQfDND/r372F3BfdrEI45 I5a4qnH2vbmVIos6zC4BdoB+NqidjvqRB9PNWkuc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Qian Cai , Yuyang Du , "Peter Zijlstra (Intel)" , Andrew Morton , Linus Torvalds , "Paul E. McKenney" , Thomas Gleixner , Will Deacon , arnd@arndb.de, frederic@kernel.org, Ingo Molnar , Sasha Levin Subject: [PATCH 4.9 200/223] locking/lockdep: Fix lock used or unused stats error Date: Fri, 2 Aug 2019 11:37:05 +0200 Message-Id: <20190802092250.101586900@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190802092238.692035242@linuxfoundation.org> References: <20190802092238.692035242@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 68d41d8c94a31dfb8233ab90b9baf41a2ed2da68 ] The stats variable nr_unused_locks is incremented every time a new lock class is register and decremented when the lock is first used in __lock_acquire(). And after all, it is shown and checked in lockdep_stats. However, under configurations that either CONFIG_TRACE_IRQFLAGS or CONFIG_PROVE_LOCKING is not defined: The commit: 091806515124b20 ("locking/lockdep: Consolidate lock usage bit initialization") missed marking the LOCK_USED flag at IRQ usage initialization because as mark_usage() is not called. And the commit: 886532aee3cd42d ("locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING") further made mark_lock() not defined such that the LOCK_USED cannot be marked at all when the lock is first acquired. As a result, we fix this by not showing and checking the stats under such configurations for lockdep_stats. Reported-by: Qian Cai Signed-off-by: Yuyang Du Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: arnd@arndb.de Cc: frederic@kernel.org Link: https://lkml.kernel.org/r/20190709101522.9117-1-duyuyang@gmail.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- kernel/locking/lockdep_proc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index a0f61effad25..c482de6f5262 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -229,6 +229,7 @@ static int lockdep_stats_show(struct seq_file *m, void *v) nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0, sum_forward_deps = 0; +#ifdef CONFIG_PROVE_LOCKING list_for_each_entry(class, &all_lock_classes, lock_entry) { if (class->usage_mask == 0) @@ -260,12 +261,12 @@ static int lockdep_stats_show(struct seq_file *m, void *v) if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ) nr_hardirq_read_unsafe++; -#ifdef CONFIG_PROVE_LOCKING sum_forward_deps += lockdep_count_forward_deps(class); -#endif } #ifdef CONFIG_DEBUG_LOCKDEP DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused); +#endif + #endif seq_printf(m, " lock-classes: %11lu [max: %lu]\n", nr_lock_classes, MAX_LOCKDEP_KEYS); -- 2.20.1