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=-2.8 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 29E1DC43444 for ; Mon, 17 Dec 2018 21:31:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E273E20874 for ; Mon, 17 Dec 2018 21:31:00 +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="IMthgdKf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733118AbeLQVa7 (ORCPT ); Mon, 17 Dec 2018 16:30:59 -0500 Received: from out002.mailprotect.be ([83.217.72.86]:38929 "EHLO out002.mailprotect.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727887AbeLQVa6 (ORCPT ); Mon, 17 Dec 2018 16:30:58 -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=7zN+oV6yRgwmz1Dto0nrm+JnXv93F1m4kcxxtGDJQcI=; b=IMthgdKf/znX M5Gz3AxEk3I7EqnXHJvFSq7ynnpaxjb4PtgkUPttVKqN7Erw6mOg5/o5a1zpKo71wUbwbuoe0wDRb Cf78hC82qYCsJKlaN1w0l/a9t7O+6u/iS1L7L50nvAerEiwV9QJbec7poID2F2y5Pxstg0xkbXsYu u82P3MYT97pHcmoTuRtTjpjDqGbVuX4q+HcL7fTGM+HRazcTiTvUdVEBAnVEtwYVw5FMi/J823clY lRG15/5qQFGvhuDjb9adr6bzNX9ZDY7HAjumKcSSuKhEvJAAisoWZzecdKBkqPVJHYbCBZonYNBKP Z0QglUCExbOMf98XxnmyhQ==; Received: from smtp-auth.mailprotect.be ([178.208.39.159]) by com-mpt-out002.mailprotect.be with esmtp (Exim 4.89) (envelope-from ) id 1gZ0TJ-0001N4-4N; Mon, 17 Dec 2018 22:30:42 +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 53835C00A8; Mon, 17 Dec 2018 22:30:34 +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 v5 00/15] locking/lockdep: Add support for dynamic keys Date: Mon, 17 Dec 2018 13:29:47 -0800 Message-Id: <20181217213002.73776-1-bvanassche@acm.org> X-Mailer: git-send-email 2.20.0.405.gbc1bbc6f85-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Originating-IP: 178.208.39.159 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 (0.07) X-Recommended-Action: accept X-Filter-ID: EX5BVjFpneJeBchSMxfU5n+CvbT4OXSwyLahOvCNVZd602E9L7XzfQH6nu9C/Fh9KJzpNe6xgvOx q3u0UDjvO1tLifGj39bI0bcPyaJsYTb/+zriNZuqQk0xRpGwjn+MTR8dtByWYYhgj25jR+mEA3YO AtfhCcV13BpIh8lqRXSSiFVwqwU9VgKUrYQ0lqWyFDaym8oavoPYsm7m1mVEGf0/5ST3nkt5XYDK YAuRpmF7E2F3eqKXiTd2ECUghryWsXVhPBs4K8hVtp6La00Uv8ZB14E0iQtvqvjtp9rD8If9bcHJ zTYM7Gz36QU/LMAvByeZp1VLEA1x/1qRPU90uCTg127TqHZDxA/kZB41Rh8wUGmdr3B4qT9RiswA A6TjCkmYneWmOLktMt7B24JcugzjEiJdFHfKejKhxr74HTqN0nsLdCG7LGfReC1C1uWeBldNoc4/ ugpbufbubK+x4pGqVAT1vWFeEhEnVslbRXVRh+7MnWbw7fXOUdDwPDg2bN87qJveuvI4FkaTzox5 7en0TkQuIdVjxFJSAPHvCxKJKuWBdR7YVGu3dD+xoi67r0TCUZsaG+mLAH7VoDC8TGpF0nrTJnXQ ungkKNbjrbxYFX5W98JZfM4UDzp+I2t3/FxvddG4mRHKJlnoc+LvLMw4Oh2LkwsmIC+tUiJAU2Hq vcLZCDNz7FE5l8aegTfrXgepXw2uOkh8BWaRmYTapEnuVpgRu+5Csn5Mqn0EOmQ4zJ5Xvbj1fZ7U ZAcZAKRxmEeggn4dXb7yqusq0s5DtHjAuWm1g4dKQcnjq+K7pxF/YQg7NrcXqRbN9FIAlKlZzBq4 o6xB5AMMdSDguIlqHHJIe5U4rz33MPOIlGKEX4NMFgsxYIHCku08yYLbMWIz8Sz3rXkToGgoPkqM hPcHscFEFmAKKS84AwX/iljz3fd1vw8CKdLIQ0mXmruaJQIieftg9oX73yAdMI5rvHm/KiZ2EoFj UffItseFo4T76UWWgwomWRcGIJOYPo3qjuJ8Dg/kZ2rBdh8HP0IdYe7j8cOpyKA69LF1Ge2GaGfx 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 v4 are: - Introduced the function lockdep_set_selftest_task() to fix a build failure for CONFIG_LOCKDEP=n. - Fixed a use-after-free issue in is_dynamic_key() by adding the following code in that function: if (!debug_locks) return true; - Changed if (WARN_ON_ONCE(!pf)) into if (!pf) to avoid that the new lockdep implementation triggers more kernel warnings than the current implementation. This keeps the build happy when doing regression tests. - Added a synchronize_rcu() call at the end of lockdep_unregister_key() to avoid a use-after-free. 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. - Rebased this patch series on top of the tip/locking/core branch. 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 | 42 +- include/linux/workqueue.h | 28 +- kernel/locking/lockdep.c | 913 +++++++++++++++--- 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, 913 insertions(+), 169 deletions(-) -- 2.20.0.405.gbc1bbc6f85-goog