From patchwork Fri Feb 26 17:52:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuah Khan X-Patchwork-Id: 12107035 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 EC9C5C433E0 for ; Fri, 26 Feb 2021 17:53:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ADDC360241 for ; Fri, 26 Feb 2021 17:53:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230260AbhBZRxZ (ORCPT ); Fri, 26 Feb 2021 12:53:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230144AbhBZRxA (ORCPT ); Fri, 26 Feb 2021 12:53:00 -0500 Received: from mail-il1-x12a.google.com (mail-il1-x12a.google.com [IPv6:2607:f8b0:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 85E44C061786 for ; Fri, 26 Feb 2021 09:52:19 -0800 (PST) Received: by mail-il1-x12a.google.com with SMTP id g9so8748971ilc.3 for ; Fri, 26 Feb 2021 09:52:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=KzQ9OBQajFeaiUpGgz5pU1UyInmaQ1PIgYZOHvN7J2s=; b=QmEx6PMwk5EzxsrPZJ6iRfQ/ny2qMbBfnWObiy0RKj7IzCtCtGd2xn3nfRRPTWrMDn 8qODazbWCshriSjXgg2GqqfyIxkQxBwY1cmWSxb2GEk7YRApPYA3iYuVChku9DJatqOG Rg8jTRSgD/ztSQ1+1eAYv8ZZWPYSsXyi4jNH0= 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=KzQ9OBQajFeaiUpGgz5pU1UyInmaQ1PIgYZOHvN7J2s=; b=fI7Z8p3KaYEvSzG3lRsn1a708fd1LWTItMZ1G64AQ9nM9ZOEcnfet05oy5cV9cD6HD x+Xyjf24a2MTD3H/v2Ej+xU8uKo2rPjhlYp5WOg5ZVIIeYIzirLegtc2nJg7NV08ix6P VtK5rFBL44tVoAGcMqgkEfQwIJ5AC5NDMRfrrtpJ9SBUEp1oJGFu1nqMyQHgh7EzCGsN Nc3SIGx6mofLb3oRq0JCM5tFa1Bj10NMAHmPEDkzDsG2cjybosXb9Ee2RRRj835D7Ilf XZX2WDVQuaSdbiYODR/rqiPHpdyDZKLZBBvsKpq03hcWf3tSr7KhW48UxtwxI54bwl+U VOdQ== X-Gm-Message-State: AOAM533XiAbkhETtzG2obj2mZFHOfmx63xHIGs7BSJqBDAK9FdkVvFz+ 4JB0c5DflIZTTuYHPDNrnOAJaA== X-Google-Smtp-Source: ABdhPJzKtNZ9DqshtlkVijD2KykbsioNqaOrCP1Wc05drU0Weq1Yrn5ll6pcxxXm1ey3JQd/0u87WQ== X-Received: by 2002:a92:cc49:: with SMTP id t9mr3302848ilq.86.1614361939062; Fri, 26 Feb 2021 09:52:19 -0800 (PST) Received: from shuah-t480s.internal (c-24-9-64-241.hsd1.co.comcast.net. [24.9.64.241]) by smtp.gmail.com with ESMTPSA id y25sm5594060ioa.5.2021.02.26.09.52.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Feb 2021 09:52:18 -0800 (PST) From: Shuah Khan To: peterz@infradead.org, mingo@redhat.com, will@kernel.org, kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org Cc: Shuah Khan , ath10k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/3] lockdep: add lockdep_assert_not_held() Date: Fri, 26 Feb 2021 10:52:13 -0700 Message-Id: X-Mailer: git-send-email 2.27.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Some kernel functions must be called without holding a specific lock. Add lockdep_assert_not_held() to be used in these functions to detect incorrect calls while holding a lock. lockdep_assert_not_held() provides the opposite functionality of lockdep_assert_held() which is used to assert calls that require holding a specific lock. Incorporates suggestions from Peter Zijlstra to avoid misfires when lockdep_off() is employed. The need for lockdep_assert_not_held() came up in a discussion on ath10k patch. ath10k_drain_tx() and i915_vma_pin_ww() are examples of functions that can use lockdep_assert_not_held(). Link: https://lore.kernel.org/lkml/37a29c383bff2fb1605241ee6c7c9be3784fb3c6.1613171185.git.skhan@linuxfoundation.org/ Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ Signed-off-by: Shuah Khan --- include/linux/lockdep.h | 11 ++++++++--- kernel/locking/lockdep.c | 5 ++++- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index b9e9adec73e8..93eb5f797fc1 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -294,8 +294,12 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) -#define lockdep_assert_held(l) do { \ - WARN_ON(debug_locks && !lockdep_is_held(l)); \ +#define lockdep_assert_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 0); \ + } while (0) + +#define lockdep_assert_not_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 1); \ } while (0) #define lockdep_assert_held_write(l) do { \ @@ -384,7 +388,8 @@ extern int lockdep_is_held(const void *); #define lockdep_is_held_type(l, r) (1) #define lockdep_assert_held(l) do { (void)(l); } while (0) -#define lockdep_assert_held_write(l) do { (void)(l); } while (0) +#define lockdep_assert_not_held(l) do { (void)(l); } while (0) +#define lockdep_assert_held_write(l) do { (void)(l); } while (0) #define lockdep_assert_held_read(l) do { (void)(l); } while (0) #define lockdep_assert_held_once(l) do { (void)(l); } while (0) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index bdaf4829098c..d3299fd85c4a 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -5472,7 +5472,10 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) int ret = 0; if (unlikely(!lockdep_enabled())) - return 1; /* avoid false negative lockdep_assert_held() */ + /* avoid false negative lockdep_assert_not_held() + * and lockdep_assert_held() + */ + return -1; raw_local_irq_save(flags); check_flags(flags);