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=-2.7 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,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 13BCBC6783B for ; Tue, 11 Dec 2018 22:15:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C251F2084E for ; Tue, 11 Dec 2018 22:15:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=mailprotect.be header.i=@mailprotect.be header.b="kBvshdmS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C251F2084E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=acm.org 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 S1726381AbeLKWOO (ORCPT ); Tue, 11 Dec 2018 17:14:14 -0500 Received: from com-out001.mailprotect.be ([83.217.72.83]:58737 "EHLO com-out001.mailprotect.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726308AbeLKWOL (ORCPT ); Tue, 11 Dec 2018 17:14:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mailprotect.be; s=mail; h=Content-Transfer-Encoding:MIME-Version:Message-Id :Date:Subject:Cc:To:From:reply-to:sender:bcc:in-reply-to:references: content-type; bh=lPIVnauzj81YfwkDDegoiE1uVpqRqpbOmNEvzTUtOr0=; b=kBvshdmSs+fT TD1jo2LCNaTq08v8PCoMLxCkhweFvIqHnYf9eBvEvqkQHNNhTpyTpzIZlxO2WXA4jM3rrEZymrbhk 7VSLsAEScw6O54VkQ3AhdB2+k/fjqj02aEmiMTZrqc0uUVAKCzPp9WJEpmfA5sVHz4suYnHMvZ7mh J8n1fUvAausmcKp05paU/qXgjVTHIiNp+tNqajKHXm2PMUiUeAk/wM+wXorRvnOg1KYBWXrL/Nu9y t/TvGb9PV5nUM446NjGmmjA3OyETAuLvPhWsMLHozQSiP0+NHFKkTlJPLQ6d2C8uxXNWxoKxnrHup xjXNz1xsEy8JeWIiEdYBcw==; Received: from smtp-auth.mailprotect.be ([178.208.39.155]) by com-mpt-out001.mailprotect.be with esmtp (Exim 4.89) (envelope-from ) id 1gWqHo-0005Lw-PR; Tue, 11 Dec 2018 23:13:53 +0100 Received: from desktop-bart.svl.corp.google.com (unknown [104.133.8.89]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp-auth.mailprotect.be (Postfix) with ESMTPSA id 83D5DC0718; Tue, 11 Dec 2018 23:13:34 +0100 (CET) From: Bart Van Assche To: peterz@infradead.org Cc: mingo@redhat.com, tj@kernel.org, longman@redhat.com, johannes.berg@intel.com, linux-kernel@vger.kernel.org, Bart Van Assche Subject: [PATCH v4 00/15] locking/lockdep: Add support for dynamic keys Date: Tue, 11 Dec 2018 14:13:06 -0800 Message-Id: <20181211221321.196536-1-bvanassche@acm.org> X-Mailer: git-send-email 2.20.0.rc2.403.gdbc3b29805-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Originating-IP: 178.208.39.155 X-SpamExperts-Domain: mailprotect.be X-SpamExperts-Username: 178.208.39.128/27 Authentication-Results: mailprotect.be; auth=pass smtp.auth=178.208.39.128/27@mailprotect.be X-SpamExperts-Outgoing-Class: ham X-SpamExperts-Outgoing-Evidence: Combined (0.08) X-Recommended-Action: accept X-Filter-ID: EX5BVjFpneJeBchSMxfU5qG7cpVmpnDvIHp2+sbGUo1602E9L7XzfQH6nu9C/Fh9KJzpNe6xgvOx q3u0UDjvO1tLifGj39bI0bcPyaJsYTb/+zriNZuqQk0xRpGwjn+MTR8dtByWYYhgj25jR+mEA3YO AtfhCcV13BpIh8lqRXSSiFVwqwU9VgKUrYQ0lqWyFDaym8oavoPYsm7m1mVEGf0/5ST3nkt5XYDK YAuRpmF7E2F3eqKXiTd2ECUghryWsXVhPBs4K8hVtp6La00Uv8ZB14E0iQtvqvjtp9rD8If9bcHJ zTYM7Gz36QU/LMAv0C6YQxDn16lwRqui2ilsPyTg127TqHZDxA/kZB41Rh8wUGmdr3B4qT9RiswA A6TjCkmYneWmOLktMt7B24Jcus2wWVbjHO/cpJpsYlvFhM+N0nsLdCG7LGfReC1C1uWeBldNoc4/ ugpbufbubK+x4pGqVAT1vWFeEhEnVslbRXVRh+7MnWbw7fXOUdDwPDg2bN87qJveuvI4FkaTzox5 7en0TkQuIdVjxFJSAPHvCxKJKuWBdR7YVGu3dD+xoi67r0TCUZsaG+mLAH7VoDC8TGpF0nrTJnXQ ungkKNbjrbxYFX5W98JZfM4UDzp+I2t3/FxvddG4mRHKJlnoc+LvLMw4Oh2LkwsmIC+tUiJAU2Hq vcLZCDNz7FE5l8aegTfrXgepXw2uOkh8BWaRmYTapEnuVpgRu+5Csn5Mqn0EOmQ4zJ5Xvbj1fZ7U ZAcZAKRxxrMZUT78gpA1Zyw3QtodznRSNA+VaZsOBFopY/kW1qm1docXitEPM13yBfBB3B5fzBq4 o6xB5AMMdSDguIlqHHJIe5U4rz33MPOIlGKEX4NMFgsxYIHCku08yYLbMWIz8Sz3rXkToGgoPkqM hPcHscFEFmAKKS84AwX/iljz3fd1vw8CKdLIQ0mXmruaJQIi+FOxgkVvyyGR6ssTaccR4EbSKT4v l+2c5ndA22w8Q+OWgwomWRcGIJOYPo3qjuJ89r6TOdr62U9MDkWGkPl9AMOpyKA69LF1Ge2GaGfx mfos7YTXbqll+CkEp8Abhi88xg9tdbvxd+VhQOn2K5bYwN40eTXlWiUAYdLmsJdAoPJvtp9WlTt+ Kq0eQx3E5oYrsjSrzniyQYOvVIVbP1OsRtMGMevVVKNikwLQ0fq/FOtFj5jedxzVymPEjnK9ocrD Qs1Q7QbJ8LleNweIjcZcgw== X-Report-Abuse-To: spam@com-mpt-mgt001.mailprotect.be Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter and Ingo, A known shortcoming of the current lockdep implementation is that it requires lock keys to be allocated statically. This forces certain unrelated synchronization objects to share keys and this key sharing can cause false positive deadlock reports. This patch series adds support for dynamic keys in the lockdep code and eliminates a class of false positive reports from the workqueue implementation. The changes compared to v3 are: - Rework the code that frees objects that are no longer used such that it is now guaranteed that a grace period elapses between last use and freeing. - The lockdep self tests pass again. - Avoid that the patch that removes all matching lock order entries can cause list corruption. Note: the change in this patch to realize that is removed again by a later patch. In other words, this change is only necessary to make the series bisectable. The changes compared to v2 are: - Made sure that all schedule_free_zapped_classes() calls are protected with the graph lock. - When removing a lock class, only recalculate lock chains that have been modified. - Combine a list_del() and list_add_tail() call into a list_move_tail() call in register_lock_class(). - Use an RCU read lock instead of the graph lock inside is_dynamic_key(). The changes compared to v1 are: - Addressed Peter's review comments: remove the list_head that I had added to struct lock_list again, replaced all_list_entries and free_list_entries by two bitmaps, use call_rcu() to free lockdep objects, add a BUILD_BUG_ON() that compares the size of struct lock_class_key and raw_spin_lock_t. - Addressed the "unknown symbol" errors reported by the build bot by adding a few #ifdef / #endif directives. Addressed the 32-bit warnings by using %d instead of %ld for array indices and by casting the array indices to unsigned int. - Removed several WARN_ON_ONCE(!class->hash_entry.pprev) statements since these duplicate the code in check_data_structures(). - Left out the patch that causes lockdep to complain if no name has been assigned to a lock object. That patch namely causes the build bot to complain about certain lock objects but I have not yet had the time to figure out the identity of these lock objects. Bart. Bart Van Assche (15): locking/lockdep: Fix required memory size reported if CONFIG_PROVE_LOCKING=n locking/lockdep: Make zap_class() remove all matching lock order entries locking/lockdep: Reorder struct lock_class members locking/lockdep: Initialize the locks_before and locks_after lists earlier locking/lockdep: Split lockdep_free_key_range() and lockdep_reset_lock() locking/lockdep: Make it easy to detect whether or not inside a selftest locking/lockdep: Free lock classes that are no longer in use locking/lockdep: Reuse list entries that are no longer in use locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count() locking/lockdep: Reuse lock chains that have been freed locking/lockdep: Check data structure consistency locking/lockdep: Verify whether lock objects are small enough to be used as class keys locking/lockdep: Add support for dynamic keys kernel/workqueue: Use dynamic lockdep keys for workqueues lockdep tests: Test dynamic key registration include/linux/lockdep.h | 38 +- include/linux/workqueue.h | 28 +- kernel/locking/lockdep.c | 884 ++++++++++++++++-- kernel/locking/lockdep_internals.h | 3 +- kernel/locking/lockdep_proc.c | 12 +- kernel/workqueue.c | 60 +- lib/locking-selftest.c | 2 + tools/lib/lockdep/include/liblockdep/common.h | 2 + tools/lib/lockdep/include/liblockdep/mutex.h | 11 +- tools/lib/lockdep/tests/ABBA.c | 9 + 10 files changed, 893 insertions(+), 156 deletions(-) -- 2.20.0.rc2.403.gdbc3b29805-goog