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=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 299A1C04EB8 for ; Wed, 28 Nov 2018 23:44:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9059206B2 for ; Wed, 28 Nov 2018 23:44:32 +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="G3ceWvkq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9059206B2 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 S1727693AbeK2Krv (ORCPT ); Thu, 29 Nov 2018 05:47:51 -0500 Received: from out002.mailprotect.be ([83.217.72.86]:42153 "EHLO out002.mailprotect.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727007AbeK2Kru (ORCPT ); Thu, 29 Nov 2018 05:47:50 -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:References :In-Reply-To:Message-Id:Date:Subject:Cc:To:From:reply-to:sender:bcc: content-type; bh=wc3OpeHu5BZObpN0LPN3EmYqY86q8cZb/pOpjiUTBfA=; b=G3ceWvkqB4SR QNZdG9CUHwm99l1R8/iyW9Tgfy+Z3CSefXtX9+l63udhVwSUlrLHVisOhj3vTAqINlcpP4ztQRGef TWkBic3q1xAp85sNJDGqq9froRmbwKgQrNpOBr9Yv4aSnSHSWhtpZ33/WVSTs3l4YXscmZJYeuABx dEuXE5BIuwh5VOyTfFSiS3xjynxrjGBxHwW51MYBCrRnX7W+8D/fOmiPaLTrMFEZSwF8ouCSu40pK GV7XOwtp1HyYdw6eZ/iQ2kRRQqk4M3jty6835EbuCWV+mw22gRNmrx7hqwEW28e7uZF86LtSNqi+M EzbGs26BFCPTMUqiBm2wdg==; Received: from smtp-auth.mailprotect.be ([178.208.39.159]) by com-mpt-out002.mailprotect.be with esmtp (Exim 4.89) (envelope-from ) id 1gS9VC-000Fm0-Oi; Thu, 29 Nov 2018 00:44:18 +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 A087AC11D1; Thu, 29 Nov 2018 00:44:16 +0100 (CET) From: Bart Van Assche To: mingo@redhat.com Cc: peterz@infradead.org, tj@kernel.org, johannes.berg@intel.com, linux-kernel@vger.kernel.org, Bart Van Assche Subject: [PATCH 23/27] locking/lockdep: Check data structure consistency Date: Wed, 28 Nov 2018 15:43:21 -0800 Message-Id: <20181128234325.110011-24-bvanassche@acm.org> X-Mailer: git-send-email 2.20.0.rc0.387.gc7a69e6b6c-goog In-Reply-To: <20181128234325.110011-1-bvanassche@acm.org> References: <20181128234325.110011-1-bvanassche@acm.org> 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: SB/global_tokens (0.0011960716015) X-Recommended-Action: accept X-Filter-ID: EX5BVjFpneJeBchSMxfU5jinzgJ1EtFkeyeuV4rfmFd602E9L7XzfQH6nu9C/Fh9KJzpNe6xgvOx q3u0UDjvO1tLifGj39bI0bcPyaJsYTb/+zriNZuqQk0xRpGwjn+MTR8dtByWYYhgj25jR+mEA3YO AtfhCcV13BpIh8lqRXSSiFVwqwU9VgKUrYQ0lqWyB41b1wEpWO6ik9HITpMsqebHcXK5F5szpMR3 ucwUCaulpCLw+Xb9GLNy0GASgpn9t8C9mOBdONdnsxgsk1D2p09kN7MM31r8n6t5T2S20aX6y7YY evlhZhZ4qit068tqq2ydL+V39l/HBScm+SV6be+d9aVwS6cHCn1lU19HAi33Iz6Zvpm8cPQnANwk DQ5BNCNwpGn8jfSb3NCl2WUq09dCYgcgr835yVjKQZA6hJL1LiMHCxRezvZaFOrUVh8zaVyj66M1 yz85ZZhpUrhTRbASVYnBhdKUnGmBdHG7BUn2dK6UtSEdwn3yFtfkzf2g6K04cY809V1JdCwiLdDQ Dow7RSjhmGOVelXQaHGaUkBvyMjbyNpr4xR6RL2C9+qlIny++hg9dJLqN5zmWqF/oNe6FVV7drXD mtOldfpWzeUCaRHvx+uLGHS3n3Y0pMd0ZyCgxZHINA6A5+7T9o6by6wCf9/ixXi9QE6xc2MJdJIs WkULIn/2FBvF31UHbsndehIqUczFWeS6sE8e1b5/UlaX0Ao5X99TlizdjWjXhcukjPvPb2ztUwUU F4ekbSpuNzlrea/7iuldgAMiBvdjMS5J8moEi3zrRvDLm1YEEdEHmFDqewO9xyOqCYO8P1aHcsG0 kWCiESR44kXyAcFBnvq0JaXhRWKyqy0OhbkmMxu2AdrcZPAiQvyjIZ4LQqnqqLEDUnB02oJPHAlf IubJYzA0XAoGECHs14pjPDDBgamvNiA5kjk+kUt44s0jst5foe/FOaCTJx4a7HWQH97sguITVg6Q TrHGofvmrHam4/RuhWzfuvHd4y0L/HyfN5U858I8R2vIYlYbA7G/CY3eeSCFRiwDn8j3yWGHtM7w dRonBy/PpUxgSFRPcWxJF+/beJHmCfSNEcGdfFKs5M18F1x96tlonSt5Ig9mwLw4vXsdf68W0InH /+bTMKNm38MHV+diwrlXuxzeO2WnJyd7g8lLLKZgdBo3YHaSgbLEg7M4I+zZPnIX6k9TnzH5sZcr MS+4ayUpOtEhdxekWDmK9g== 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 Debugging lockdep data structure inconsistencies is challenging. Add disabled code that verifies data structure consistency at runtime. Signed-off-by: Bart Van Assche --- kernel/locking/lockdep.c | 142 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 288a2f6fd0ef..141bb0662ff5 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -72,6 +72,8 @@ module_param(lock_stat, int, 0644); #define lock_stat 0 #endif +static bool check_data_structure_consistency; + /* * lockdep_lock: protects the lockdep graph, the hashes and the * class/list/hash allocators. @@ -736,6 +738,135 @@ static bool assign_lock_key(struct lockdep_map *lock) return true; } +/* Check whether element @e occurs in list @h */ +static bool in_list(struct list_head *e, struct list_head *h) +{ + struct list_head *f; + + list_for_each(f, h) + if (e == f) + return true; + + return false; +} + +/* + * Check whether entry @e occurs in any of the locks_after or locks_before + * lists. + */ +static bool in_any_class_list(struct list_head *e) +{ + struct lock_class *class; + int i; + + for (i = 0; i < ARRAY_SIZE(lock_classes); i++) { + class = &lock_classes[i]; + if (in_list(e, &class->locks_after) || + in_list(e, &class->locks_before)) + return true; + } + return false; +} + +static bool class_lock_list_valid(struct lock_class *c, struct list_head *h) +{ + struct lock_list *e; + + list_for_each_entry(e, h, lock_order_entry) { + if (e->links_to != c) { + printk(KERN_INFO "class %s: mismatch for lock entry %ld; class %s <> %s", + c->name ? : "(?)", e - list_entries, + e->links_to && e->links_to->name ? + e->links_to->name : "(?)", + e->class && e->class->name ? e->class->name : + "(?)"); + return false; + } + } + return true; +} + +static u16 chain_hlocks[]; + +static bool check_lock_chain_key(struct lock_chain *chain) +{ + u64 chain_key = 0; + int i; + + for (i = chain->base; i < chain->base + chain->depth; i++) + chain_key = iterate_chain_key(chain_key, chain_hlocks[i] + 1); + /* + * The 'unsigned long long' casts avoid that a compiler warning + * is reported when building tools/lib/lockdep. + */ + if (chain->chain_key != chain_key) + printk(KERN_INFO "chain %lld: key %#llx <> %#llx\n", + (unsigned long long)(chain - lock_chains), + (unsigned long long)chain->chain_key, + (unsigned long long)chain_key); + return chain->chain_key == chain_key; +} + +static bool check_data_structures(void) +{ + struct lock_class *class; + struct lock_chain *chain; + struct hlist_head *head; + struct lock_list *e; + int i; + + /* + * Check whether all list entries that are in use occur in a class + * lock list. + */ + list_for_each_entry(e, &all_list_entries, alloc_entry) { + if (!in_any_class_list(&e->lock_order_entry)) { + printk(KERN_INFO "list entry %ld is not in any class list; class %s <> %s\n", + e - list_entries, + e->class->name ? : "(?)", + e->links_to->name ? : "(?)"); + return false; + } + } + + /* + * Check whether all list entries that are not in use do not occur in + * a class lock list. + */ + list_for_each_entry(e, &free_list_entries, alloc_entry) { + if (in_any_class_list(&e->lock_order_entry)) { + printk(KERN_INFO "list entry %ld occurs in a class list; class %s <> %s\n", + e - list_entries, + e->class && e->class->name ? e->class->name : + "(?)", + e->links_to && e->links_to->name ? + e->links_to->name : "(?)"); + return false; + } + } + + /* Check whether all classes have valid lock lists. */ + for (i = 0; i < ARRAY_SIZE(lock_classes); i++) { + class = &lock_classes[i]; + if (!class->locks_before.next) + continue; + if (!class_lock_list_valid(class, &class->locks_before)) + return false; + if (!class_lock_list_valid(class, &class->locks_after)) + return false; + } + + /* Check the chain_key of all lock chains. */ + for (i = 0; i < ARRAY_SIZE(chainhash_table); i++) { + head = chainhash_table + i; + hlist_for_each_entry_rcu(chain, head, entry) + if (!check_lock_chain_key(chain)) + return false; + } + + return true; +} + static void init_lists(void) { int i; @@ -4294,6 +4425,14 @@ static void free_zapped_classes(struct list_head *zapped_classes) unsigned long flags; int locked; + raw_local_irq_save(flags); + locked = graph_lock(); + if (check_data_structure_consistency) + WARN_ON_ONCE(!check_data_structures()); + if (locked) + graph_unlock(); + raw_local_irq_restore(flags); + if (list_empty(zapped_classes)) return; @@ -4314,6 +4453,9 @@ static void free_zapped_classes(struct list_head *zapped_classes) if (locked) graph_unlock(); raw_local_irq_restore(flags); + + if (check_data_structure_consistency) + WARN_ON_ONCE(!check_data_structures()); } /* -- 2.20.0.rc0.387.gc7a69e6b6c-goog