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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 76FE1C10F11 for ; Wed, 24 Apr 2019 10:20:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 34DAF2175B for ; Wed, 24 Apr 2019 10:20:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="tvZwlW5c" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729304AbfDXKU4 (ORCPT ); Wed, 24 Apr 2019 06:20:56 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:42898 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727297AbfDXKUx (ORCPT ); Wed, 24 Apr 2019 06:20:53 -0400 Received: by mail-pl1-f194.google.com with SMTP id x15so4712020pln.9 for ; Wed, 24 Apr 2019 03:20:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Fb2EnMzMz2ypaDEqcSzmRBnRvvy4LG0Bkb4/NEy/6yA=; b=tvZwlW5cyD0vQD+fjDSYBUaHF6PyD+Xpq5o9pNthq3MKHZZDqN8vcCNX24L8yo6ipu 0szBNfnjmeqJs2ug+qejKkRfGffs8VxL3aBnc2LmZ4lRCa2mso0YUnAnniOG69hEXKVX 8HjNMK5AE/tw22INvefEZTIEZJncDFhOXrty2MU4qHN3rb+tgTQSMxuETV9EZowtIDhO L6EjIvq9t0J8WH2yerLXYFtOIHpxWhCHkfwaKOcTIekU4aj5YGAuWX86Q3ciD3xcQCKK PirUD6yPKInIFKA2hhAETzeWskYYD7qDfAGSHrgDqF3miqE/8nv14lGuoWU+V/15GlPh JvAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Fb2EnMzMz2ypaDEqcSzmRBnRvvy4LG0Bkb4/NEy/6yA=; b=aNgLuq8T2Uv/sEgWrUvKjnuTANt6V7efsMa3iLbPZ3wkkoABT61eEVCcsou3Iv9SSe U8oUYbMSodnGXRPlWyYnLGyZRlnHco84rZ+COzfDUpIqJB0HPltPzFirjnGQlXhEvYu6 zL2IbfCeCixq7iNzz5Yc+aZdfMkelQZ32cEFLSjhtJH4EWULzAtNBE29xbbVPCZK2rnn x4oEB5wb1xhGuHosXDWv6RC1mxN9FyA12MHd4hqUda7r6XMdp9itkT0PXCaOhooW0AKH aLa1fdDExfRwupSnFAiy09wA36B8+rVAC/cUDzgzJre2jS4F3/+cVGgWtxU2R2ZcHR1x wUjQ== X-Gm-Message-State: APjAAAVe9YcMpnlAC4Fx9eZS7rl4dj8rUmi3yK2AOo7IjIbJr8eZ0XAC Vq3IdAnq5KGVNu6H1evSBbc= X-Google-Smtp-Source: APXvYqw7xsJ3zxV0np2hdQ6aj+WwDIFACjlHf4OiOOlnIxg1cse9kHpX/7wftB/0BtYNbVIGpFGnpQ== X-Received: by 2002:a17:902:ba85:: with SMTP id k5mr31584379pls.270.1556101252308; Wed, 24 Apr 2019 03:20:52 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id v19sm25051604pfn.62.2019.04.24.03.20.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Apr 2019 03:20:51 -0700 (PDT) From: Yuyang Du To: peterz@infradead.org, will.deacon@arm.com, mingo@kernel.org Cc: bvanassche@acm.org, ming.lei@redhat.com, frederic@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, Yuyang Du Subject: [PATCH 08/28] locking/lockdep: Define INITIAL_CHAIN_KEY for chain keys to start with Date: Wed, 24 Apr 2019 18:19:14 +0800 Message-Id: <20190424101934.51535-9-duyuyang@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20190424101934.51535-1-duyuyang@gmail.com> References: <20190424101934.51535-1-duyuyang@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Chain keys are computed using Jenkins hash function, which needs an initial hash to start with. Dedicate a macro to make this clear and configurable. A later patch changes this initial chain key. Signed-off-by: Yuyang Du --- include/linux/lockdep.h | 1 + init/init_task.c | 2 +- kernel/locking/lockdep.c | 18 +++++++++--------- 3 files changed, 11 insertions(+), 10 deletions(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 751a2cc..bb47d7c 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -229,6 +229,7 @@ struct lock_chain { * bitfield and hitting the BUG in hlock_class(). */ #define MAX_LOCKDEP_KEYS ((1UL << MAX_LOCKDEP_KEYS_BITS) - 1) +#define INITIAL_CHAIN_KEY 0 struct held_lock { /* diff --git a/init/init_task.c b/init/init_task.c index 1b15cb9..afa6ad7 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -167,7 +167,7 @@ struct task_struct init_task #endif #ifdef CONFIG_LOCKDEP .lockdep_depth = 0, /* no locks held yet */ - .curr_chain_key = 0, + .curr_chain_key = INITIAL_CHAIN_KEY, .lockdep_recursion = 0, #endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 4ce0e39..3055ea7 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -361,7 +361,7 @@ static inline u64 iterate_chain_key(u64 key, u32 idx) inline void lockdep_init_task(struct task_struct *task) { task->lockdep_depth = 0; /* no locks held yet */ - task->curr_chain_key = 0; + task->curr_chain_key = INITIAL_CHAIN_KEY; task->lockdep_recursion = 0; } @@ -852,7 +852,7 @@ static bool class_lock_list_valid(struct lock_class *c, struct list_head *h) static bool check_lock_chain_key(struct lock_chain *chain) { #ifdef CONFIG_PROVE_LOCKING - u64 chain_key = 0; + u64 chain_key = INITIAL_CHAIN_KEY; int i; for (i = chain->base; i < chain->base + chain->depth; i++) @@ -2414,7 +2414,7 @@ static u64 print_chain_key_iteration(int class_idx, u64 chain_key) print_chain_keys_held_locks(struct task_struct *curr, struct held_lock *hlock_next) { struct held_lock *hlock; - u64 chain_key = 0; + u64 chain_key = INITIAL_CHAIN_KEY; int depth = curr->lockdep_depth; int i = get_first_held_lock(curr, hlock_next); @@ -2434,7 +2434,7 @@ static u64 print_chain_key_iteration(int class_idx, u64 chain_key) static void print_chain_keys_chain(struct lock_chain *chain) { int i; - u64 chain_key = 0; + u64 chain_key = INITIAL_CHAIN_KEY; int class_id; printk("depth: %u\n", chain->depth); @@ -2742,7 +2742,7 @@ static void check_chain_key(struct task_struct *curr) #ifdef CONFIG_DEBUG_LOCKDEP struct held_lock *hlock, *prev_hlock = NULL; unsigned int i; - u64 chain_key = 0; + u64 chain_key = INITIAL_CHAIN_KEY; for (i = 0; i < curr->lockdep_depth; i++) { hlock = curr->held_locks + i; @@ -2766,7 +2766,7 @@ static void check_chain_key(struct task_struct *curr) if (prev_hlock && (prev_hlock->irq_context != hlock->irq_context)) - chain_key = 0; + chain_key = INITIAL_CHAIN_KEY; chain_key = iterate_chain_key(chain_key, hlock->class_idx); prev_hlock = hlock; } @@ -3681,14 +3681,14 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, /* * How can we have a chain hash when we ain't got no keys?! */ - if (DEBUG_LOCKS_WARN_ON(chain_key != 0)) + if (DEBUG_LOCKS_WARN_ON(chain_key != INITIAL_CHAIN_KEY)) return 0; chain_head = 1; } hlock->prev_chain_key = chain_key; if (separate_irq_context(curr, hlock)) { - chain_key = 0; + chain_key = INITIAL_CHAIN_KEY; chain_head = 1; } chain_key = iterate_chain_key(chain_key, class_idx); @@ -4530,7 +4530,7 @@ static void remove_class_from_lock_chain(struct pending_free *pf, return; recalc: - chain_key = 0; + chain_key = INITIAL_CHAIN_KEY; for (i = chain->base; i < chain->base + chain->depth; i++) chain_key = iterate_chain_key(chain_key, chain_hlocks[i] + 1); if (chain->depth && chain->chain_key == chain_key) -- 1.8.3.1