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 8AC46C43387 for ; Wed, 9 Jan 2019 21:03:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D296206B7 for ; Wed, 9 Jan 2019 21:03:05 +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="VutswhSI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727765AbfAIVDE (ORCPT ); Wed, 9 Jan 2019 16:03:04 -0500 Received: from out002.mailprotect.be ([83.217.72.86]:35041 "EHLO out002.mailprotect.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727570AbfAIVC6 (ORCPT ); Wed, 9 Jan 2019 16:02:58 -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:References :In-Reply-To:Message-Id:Date:Subject:Cc:To:From:reply-to:sender:bcc: content-type; bh=gR/VynVKG44fRcUkOLIGF+ZwdosY/lkukVz3eTd4cKM=; b=VutswhSITZlo jxvSy2oeCrkNk/ER/ObVPswN0fV3WOOyX6gVgJdlc57cpkOAFfDkWLVb5CfzVs1ITahfkpuLOWm59 6US5vnOzGMpS+yFBJZt+LC6tLvFj6k5Y5vJxPY4vNcA2rtNYn2QRr3vxbYWpWMvjCSkDtK0Wf8Oc/ WCyWvQG/LM3tTPp+/qbV3qkR3ykmoeV16m/oulXFMs6nIyxHrjjTfEUpUWA3qhPxKEeV6y2kXdHNs KvBlHNS+9wHvS9VYEcO48nJOzeaZy9oJXIUwAVFrFv78/pHOhFjx+yckpwtnykdvO/IVHMIqjwfNg Khjn25sYgcIJQkS7FXvH5g==; Received: from smtp-auth.mailprotect.be ([178.208.39.159]) by com-mpt-out002.mailprotect.be with esmtp (Exim 4.89) (envelope-from ) id 1ghKzu-0009Jz-Vc; Wed, 09 Jan 2019 22:02:47 +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 1454BC0687; Wed, 9 Jan 2019 22:02:41 +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 , Johannes Berg Subject: [PATCH v6 12/16] locking/lockdep: Check data structure consistency Date: Wed, 9 Jan 2019 13:02:00 -0800 Message-Id: <20190109210204.192109-13-bvanassche@acm.org> X-Mailer: git-send-email 2.20.1.97.g81188d93c3-goog In-Reply-To: <20190109210204.192109-1-bvanassche@acm.org> References: <20190109210204.192109-1-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 (0.00207606592447) X-Recommended-Action: accept X-Filter-ID: EX5BVjFpneJeBchSMxfU5m0LG5wvthHCFwUjAmzo3r9602E9L7XzfQH6nu9C/Fh9KJzpNe6xgvOx q3u0UDjvO1tLifGj39bI0bcPyaJsYTb/+zriNZuqQk0xRpGwjn+MTR8dtByWYYhgj25jR+mEA3YO AtfhCcV13BpIh8lqRXSSiFVwqwU9VgKUrYQ0lqWyFDaym8oavoPYsm7m1mVEGf0/5ST3nkt5XYDK YAuRpmF7E2F3eqKXiTd2ECUghryWXlqwG31yUGf3t09vBVYS71V1Pk0aHudBU1wyWVTA5OYS1waI XXCBiQFDV0yen8nGcSeERs4TOTnIH1kc1IWc5eLazqbUYkjl7F1LyK0RORq9ezGj7cxAYzB80BAN JS2TSNgvEAWLFiDAlQR6Wu0I/iWDegq4fQ11AxLVlrI7DVH6GzPz+r852EXXeYX4ImMyzDg6HYuT CyYgL61SIkBTYXPEvhymCNb22qmKERGbL1SqvGGff0htQqhQf0/aDrhpLM4xnCPpmyyS7jgD9Nen VVoB/PLX+rmdznc91veCJAwpCI+5VHpzDqRcT2+GtIE8SRAgmLDKAcp9i+Q+BEiSUj07SNjVkl0P Pj+OUYZX3/3Z86X+I1ED1LLv7p/g4HOOdbYb9IXfYGRpVS/0hA4Mwp9kB6JZdl+SJy+nWImyKEy/ zJE11ZjKQFiKV8EwnkodMjMm/D2rEPnNAuCCnt9B91Ax/uigYcgpQGDKFCrOdd8gr/U0flMcy2Vi /IcBgY4aVBKUAPQbBk8nfWT8Lcjyyn9ZSA9YgSwQmLSJwsFnO3lUxpF8dVvwCXY/4mE1q/c/E53d gi3vLmcjfrrMypRHn7OOqpiCgGRKllFsZ2U4mg8rwDNP6f68eQMaGABFR3/XX1KrFIDnIhhlHDLh vRwgYpikjrjEsQHYqzPksYepQjQSeP/rn+UB/EmrduGPxHj/dKsQ+WcgzL7pTOYRE2yEvlBrMyfp YuyanAZpMXssfrVwLrD8rqLg0SqQCDr4y/2a/qbXAUfyfj3i0I3UfX/4ndwMQJ1xaQdr/FIdEU2Q lt/YhBKQrXFod+WvUUP1Uys1SCu8wQmWlqgUhZKbKdwa/OuO5TcDeKjrEmYPn2IVWRtfdRHps2br TOkutpvyrdmtvbYO9ASW9x0dzW2b+IEXgSV5FVT0nNNOs1IDBtijAxf8XG910biZEcomWehz4u8s zDg6HYuTCyYgL61SIkBTYSiCBqrB4vMmHpjmx6wTDBzk2EPy497nssgnoMkIb3rMdj8luXC7km26 QtXP9s02LA== 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 code that verifies data structure consistency at runtime. That code is disabled by default because it is very CPU intensive. Cc: Peter Zijlstra Cc: Waiman Long Cc: Johannes Berg Signed-off-by: Bart Van Assche --- kernel/locking/lockdep.c | 170 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 170 insertions(+) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index a8ea03bfc944..acf61dbb8b30 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -74,6 +74,8 @@ 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. @@ -760,6 +762,81 @@ 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, entry) { + if (e->links_to != c) { + printk(KERN_INFO "class %s: mismatch for lock entry %ld; class %s <> %s", + c->name ? : "(?)", + (unsigned long)(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) +{ +#ifdef CONFIG_PROVE_LOCKING + 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; +#else + return true; +#endif +} + static bool list_entry_being_freed(int list_entry_idx) { struct pending_free *pf; @@ -773,6 +850,97 @@ static bool list_entry_being_freed(int list_entry_idx) return false; } +static bool in_any_zapped_class_list(struct lock_class *class) +{ + struct pending_free *pf; + int i; + + for (i = 0, pf = pending_free; i < ARRAY_SIZE(pending_free); + i++, pf++) + if (in_list(&class->lock_entry, &pf->zapped_classes)) + return true; + + return false; +} + +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 classes occur in a lock list. */ + for (i = 0; i < ARRAY_SIZE(lock_classes); i++) { + class = &lock_classes[i]; + if (!in_list(&class->lock_entry, &all_lock_classes) && + !in_list(&class->lock_entry, &free_lock_classes) && + !in_any_zapped_class_list(class)) { + printk(KERN_INFO "class %px/%s is not in any class list\n", + class, class->name ? : "(?)"); + return false; + 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_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; + } + } + + /* + * Check whether all list entries that are in use occur in a class + * lock list. + */ + for_each_set_bit(i, list_entries_in_use, ARRAY_SIZE(list_entries)) { + if (list_entry_being_freed(i)) + continue; + e = list_entries + i; + if (!in_any_class_list(&e->entry)) { + printk(KERN_INFO "list entry %d is not in any class list; class %s <> %s\n", + (unsigned int)(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. + */ + for_each_clear_bit(i, list_entries_in_use, ARRAY_SIZE(list_entries)) { + if (WARN_ON_ONCE(list_entry_being_freed(i))) + return false; + e = list_entries + i; + if (in_any_class_list(&e->entry)) { + printk(KERN_INFO "list entry %d occurs in a class list; class %s <> %s\n", + (unsigned int)(e - list_entries), + e->class && e->class->name ? e->class->name : + "(?)", + e->links_to && e->links_to->name ? + e->links_to->name : "(?)"); + return false; + } + } + + return true; +} + /* * Initialize the lock_classes[] array elements, the free_lock_classes list * and also the pending_free[] array. @@ -4376,6 +4544,8 @@ static void free_zapped_classes(struct rcu_head *ch) if (!graph_lock()) goto restore_irqs; pf->scheduled = false; + if (check_data_structure_consistency) + WARN_ON_ONCE(!check_data_structures()); list_for_each_entry(class, &pf->zapped_classes, lock_entry) { reinit_class(class); } -- 2.20.1.97.g81188d93c3-goog